See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

COPPER (See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

symbol Cu, atomic See also:

• WEIGHT

weight 63.1, H=1, or 63.6, O = 16)  , a See also:

• METAL
• METAL (through Fr. from Lat. metallum, mine, quarry, adapted from Gr. µATaXAov, in the same sense, probably connected with ,ueraAAdv, to search after, explore, µeTa, after, aAAos, other)

metal which has been known to and used by the human See also:

• RACE

race from the most remote periods . Its alloy with See also:

• TIN (Lat.- stannum, whence the chemical symbol " Sn "; atomic weight =117.6, 0=16)

tin (See also:

• BRONZE

bronze) was the first metallic See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound in See also:

• COMMON

common use by mankind, and so extensive and characteristic was its employment in pre-historic times that the See also:

• EPOCH (Gr. E7roxij, holding in suspense, a pause, from E1rxav, to hold up, to stop)

epoch is known as the Bronze See also:

• AGE (Fr. age, through late Lat. aetaticum, from aetas)

Age . By the Greeks and See also:

• ROMANS
• ROMANS, EPISTLE TO THE

Romans both the metal and its See also:

• ALLOYS (through the Fr. aloyer, from Lat. alligare, to combine)

alloys were indifferently known as xaAicbr and aes . As, according to See also:

• PLINY, THE ELDER
• PLINY, THE YOUNGER

Pliny, the See also:

• ROMAN

Roman See also:

• SUPPLY (through Fr. from Lat. supplere, to fill up)

supply was chiefly See also:

• DRAWN

drawn from See also:

• CYPRUS
• CYPRUS, CHURCH OF

Cyprus, it came to be termed aes cyprium, which was gradually shortened to cyprium, . and corrupted into cuprum, whence comes the See also:

• ENGLISH

English word See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper, the See also:

• FRENCH
• FRENCH, DANIEL CHESTER (1850– )
• FRENCH, NICHOLAS (1604-1678)

French cuivre, and the See also:

• GERMAN
• GERMAN, DUTCH AND SCANDINAVIAN

German Kupfer . Copper is a brilliant metal of a See also:

• PECULIAR

peculiar red See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour which assumes a pinkish or yellowish tinge on a freshly fractured See also:

• SURFACE

surface of the pure metal, and is purplish when the metal contains cuprous See also:

• OXIDE

oxide . Its specific gravity varies between 8.91 and 8.95, according to the treatment to which it may have been subjected; J . F . W . Hampe gives 8.945 (1o) for perfectly pure and compact copper . See also:

• ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

Ordinary commercial copper is somewhat porous and has a specific gravity ranging from 8.2 to 8.5 . It takes a brilliant See also:

• POLISH

polish, is in a high degree malleable and ductile, and in tenacity it only falls See also:

• SHORT, FRANCIS JOB (1857– )

short of See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron, exceeding in that quality both See also:

• SILVER

silver and See also:

• GOLD
• GOLD [symbol Au, atomic weight 195.7(H = 1),197.2(0 =16)]

gold . By different authorities its melting-point is stated at from l000° to 1200° C.; C .

T . Heycock and F . H . See also:

• NEVILLE, GEORGE (c. 1432-1476)
• NEVILLE, or NEVILL
• NEVILLE, RALPH (d. 1244)

Neville give 1o8o •5; P . Dejean gives 1085° as the freezing-point . The molten metal is See also:

• SEA (in O. Eng. sae, a common Teutonic word; cf. Ger. See, Dutch Zee, &c.; the ultimate source is uncertain)
• SEA, COMMAND OF THE

sea-See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green in colour, and at higher temperatures (in the electric arc) it vaporizes and See also:

• BURNS, JOHN (1858– )
• BURNS, ROBERT (1759-1796)
• BURNS, SIR GEORGE

burns with a green See also:

• FLAME (Lat. flamma; the root flag- appears in flagrare, to burn, blaze, and Gr. d, XEryew)

flame . G . W . A . Kahlbaum succeeded in subliming the metal in a vacuum, and H . See also:

• MOISSAN, HENRI (1852-1907)

Moissan (Compt. rend., 1905, 141, p . 853) distilled it in the electric See also:

• FURNACE

furnace .

Molten copper absorbs See also:

• CARBON (symbol C, atomic weight 12)

carbon monoxide, See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen and See also:

• SULPHUR

sulphur dioxide; it also appears to decompose See also:

• HYDROCARBONS

hydrocarbons (methane, ethane), absorbing the hydrogen and the carbon separating out . These occluded gases are all liberated when the copper cools, and so give rise to porous castings, unless See also:

• SPECIAL

special precautions are taken . The gases are also expelled from the molten metal by See also:

• LEAD
• LEAD (pronounced iced)

lead, carbon dioxide, or See also:

• WATER

water vapour . Its specific See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat is o•o899 at o° C. and 0•0942 at See also:

• IOO

Ioo°; the coefficient of linear expansion per I° C. is o•oo1869 . In electric conductivity it stands next to silver; the conducting See also:

• POWER [WILLIAM GRATTAN] TYRONE (1797-1841)

power of silver being equal to Too, that of perfectly pure copper is given by A . Matthiessen as 96.4 at 13° C . Copper is not affected by exposure in dry See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air, but in a moist See also:

• ATMOSPHERE (Gr. fir µ6r, vapour; orkaipa, a sphere)

atmosphere, containing carbonic See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid, it becomes coated with a green basic carbonate . When heated or rubbed it emits a peculiar disagreeable odour . Sulphuric and hydrochloric acids have little or no See also:

• ACTION

action upon it at ordinary temperatures, even when in a See also:

• FINE

fine See also:

• STATE
• STATE, GREAT OFFICERS OF

state of See also:

• DIVISION (from Lat. dividere, to break up into parts, separate)

division; but on See also:

• HEATING

heating, copper sulphate and sulphur dioxide are formed in the first See also:

• CASE
• CASE, JOHN (d. 1600)

case, and cuprous chloride and hydrogen in the second . Concentrated nitric acid has also very little action, but with the dilute acid a vigorous action ensues . The first products of this reaction are copper nitrate and nitric oxide, but, as the concentration of the copper nitrate increases, nitrous oxide and, eventually, See also:

• FREE

free See also:

• NITROGEN [symbol N., atomic weight 14.01, 0=16]

nitrogen are liberated . Many colloidal solutions of copper have been obtained .

A reddish-See also:

• BROWN
• BROWN, CHARLES BROCKDEN (1771-181o)
• BROWN, FORD MADOX (1821-1893)
• BROWN, FRANCIS (1849- )
• BROWN, GEORGE (1818-188o)
• BROWN, HENRY KIRKE (1814-1886)
• BROWN, JACOB (1775–1828)
• BROWN, JOHN (1715–1766)
• BROWN, JOHN (1722-1787)
• BROWN, JOHN (1735–1788)
• BROWN, JOHN (1784–1858)
• BROWN, JOHN (1800-1859)
• BROWN, JOHN (1810—1882)
• BROWN, JOHN GEORGE (1831— )
• BROWN, ROBERT (1773-1858)
• BROWN, SAMUEL MORISON (1817—1856)
• BROWN, SIR GEORGE (1790-1865)
• BROWN, SIR JOHN (1816-1896)
• BROWN, SIR WILLIAM, BART
• BROWN, THOMAS (1663-1704)
• BROWN, THOMAS (1778-1820)
• BROWN, THOMAS EDWARD (1830-1897)
• BROWN, WILLIAM LAURENCE (1755–1830)

brown See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution is obtained from solutions of copper chloride, stannous chloride and an alkaline tartrate (Lottermoser, Anorganische Colloide, 1901) . Occurrence.—Copper is widely distributed in nature, occurring in most soils, ferruginous See also:

• MINERAL

mineral See also:

• WATERS, TERRITORIAL

waters, and ores . It has been discovered in seaweed; in the See also:

• BLOOD

blood of certain See also:

• CEPHALOPODA

Cephalopoda and Ascidia as haemocyanin, a substance resembling the ferruginous haemoglobin, and of a See also:

• SPECIES

species of Limulus; in See also:

• STRAW

straw, See also:

• HAY
• HAY (a word common in various forms to Teutonic languages; cf. Ger. Heu, Dutch hooi; the root from which it is derived, meaning " to cut," is also seen in " to hew "; cf. " hoe ")
• HAY, GEORGE (1729—1811)
• HAY, GILBERT
• HAY, JOHN (1838–1905)

hay, eggs, See also:

• CHEESE (Lat. caseus)

cheese, See also:

• MEAT

meat, and other See also:

• FOOD
• FOOD (like the verb " to feed," from a Teutonic root, whence O. Eng. foda; cf. " fodder "; connected with Gr. lrareicOae, to feed)

food-stuffs; in the See also:

• LIVER (O. Eng. lifer; cf. cognate forms, Dutch lever, Ger. Leber, Swed. lefver, &c.; the O. H. Ger. forms are libara, lipora, &c.; the Teut. word has been connected with Gr. i'prap and Lat. jecur)

liver and kidneys, and, in traces, in the blood of See also:

• MAN
• MAN, ISLE OF (anc. Mona)

man and other animals (as an entirely See also:

• ADVENTITIOUS (from Lat. adventicius, coming from abroad)

adventitious constituent, however); it has also been shown by A . H . See also:

• CHURCH
• CHURCH (according to most authorities derived from the Gr. Kvpcaxov [&wµa], " the Lord's [house]," and common to many Teutonic, Slavonic and other languages under various forms—Scottish kirk, Ger. Kirche, Swed. kirka, Dan. kirke, Russ. tserkov, Buig. cerk
• CHURCH, FREDERICK EDWIN (1826-1900)
• CHURCH, GEORGE EARL (1835–1910)
• CHURCH, RICHARD WILLIAM (1815–189o)
• CHURCH, SIR RICHARD (1784–1873)

Church to exist to the extent of 5.9% in turacin, the colouring-See also:

• MATTER

matter of the wing-feathers of the Turaco . Native copper, sometimes termed by miners malleable or virgin copper, occurs as a mineral having all the properties of the smelted metal . It crystallizes in the cubic See also:

• SYSTEM

system, but the crystals are often flattened, elongated, rounded or otherwise distorted . Twins are common . Usually the metal is arborescent, dendritic, filiform, See also:

• MOSS

moss-like or laminar . Native copper is found in most copper-mines, usually in the upper workings, where the See also:

• DEPOSIT (Lat. depositurn, from deponere, to lay down, to put in the care of)

deposit has been exposed to atmospheric influences . The metal seems to have been reduced from solutions of its salts, and deposits may be formed around mine-See also:

• TIMBER

timber or on iron See also:

• OBJECTS

objects . It of ten fills cracks and fissures in the See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock .

It is not infrequently found in See also:

• SERPENTINE

serpentine, and in basic eruptive rocks, where it occurs as See also:

• VEINS

veins and in amygdales . The largest known deposits are those in the See also:

• LAKE
• LAKE, GERARD LAKE, 1ST VISCOUNT (1744-1808)

Lake See also:

• SUPERIOR

Superior region, near Keweenaw Point, See also:

• MICHIGAN
• MICHIGAN, LAKE
• MICHIGAN, UNIVERSITY OF

Michigan, where masses upwards of 400 tons in See also:

• WEIGHT

weight have been discovered . The metal was formerly worked by the See also:

• INDIANS, NORTH AMERICAN

Indians for implements and ornaments . It occurs in a See also:

• SERIES (a Latin word from serere, to join)

series of amygdaloidal dolerites or diabases, and in the associated sandstones and conglomerates . Native silver occurs with the copper, in some cases embedded in it, like crystals in a See also:

• PORPHYRY (IlopcPisptos) (A.D. 233-c. 304)

porphyry . The copper is also accompanied by See also:

• EPIDOTE

epidote, See also:

• CALCITE

calcite, See also:

• PREHNITE

prehnite, See also:

• ANALCITE

analcite and other zeolitic minerals . Pseudomorphs after calcite are known; and it is notable that native copper occurs pseudomorphous after See also:

• ARAGONITE

aragonite at Corocoro, in See also:

• BOLIVIA

Bolivia, where the copper is disseminated through See also:

• SANDSTONE

sandstone . Ores.—The See also:

• PRINCIPAL

principal ores of copper are the oxides See also:

• CUPRITE

cuprite and See also:

• MELACONITE

melaconite, the See also:

• CARBONATES

carbonates See also:

• MALACHITE

malachite and chessylite, the basic chloride See also:

• ATACAMITE

atacamite, the silicate See also:

• CHRYSOCOLLA

chrysocolla, the sulphides chalcocite, chalcopyrite, See also:

• ERUBESCITE

erubescite and See also:

• TETRAHEDRITE

tetrahedrite . Cuprite (q.v.) occurs in most cupriferous mines, but never by itself in large quantities . Melaconite (q.v.) was formerly largely worked in the Lake Superior region, and is abundant in some of the mines of See also:

• TENNESSEE

Tennessee and the See also:

• MISSISSIPPI

Mississippi valley . Malachite is a valuable ore containing about 56% of the metal; it is obtained in very large quantities from See also:

• SOUTH
• SOUTH, ROBERT (1634–1716)

South See also:

• AUSTRALIA

Australia, See also:

• SIBERIA

Siberia and other localities . Frequently intermixed with the green malachite is the See also:

• BLUE (common in different forms to most European languages)

blue carbonate chessylite or See also:

• AZURITE, or CHESSYLITE

azurite (q.v.), an ore containing when pure 55'16% of the metal .

Atacamite (q.v.) occurs chiefly in See also:

• CHILE, or CHILI (derived, it is said, from the Quichua chin , cold, or tchili, snow)

Chile and See also:

• PERU
• PERU (apparently from Biru, a small river on the west coast of Colombia, where Pizarro landed)

Peru . Chrysocolla (q.v.) contains in the pure state 30% of the metal; it is an abundant ore in Chile, See also:

• WISCONSIN (known as " the Badger' state ")
• WISCONSIN, UNIVERSITY OF

Wisconsin and See also:

• MISSOURI

Missouri . The sulphur compounds of copper are, however, the most valuable from the economic point of view . Chalcocite, redruthite, copper-glance (q.v.) or vitreous copper (Cu2S) contains about 8o % of copper . Copper See also:

• PYRITES

pyrites, or chalcopyrite, contains 34.6% of copper when pure; but many of the ores, such as those worked specially by wet processes on See also:

• ACCOUNT
• ACCOUNT (through O. Fr. acont, Late Lat. comptum, cornputare, to calculate)

account of the presence of a large proportion of iron sulphide, contain less than 5% of copper . Cornish ores are almost entirely pyritic; and indeed it is from such ores that by far the largest proportion of copper is extracted throughout the See also:

• WORLD

world . In See also:

• CORNWALL

Cornwall copper lodes usually run See also:

• EAST
• EAST, ALFRED (1849- )

east and See also:

• WEST
• WEST, BENJAMIN (1738-1820)
• WEST, NICHOLAS (1461-1533)

west . They occur both in the " killas " or See also:

• CLAY (from O. Eng. claeg, a word common in various forms to Teutonic languages, cf. Ger. Klei)
• CLAY, CASSIUS MARCELLUS (1810-1903)
• CLAY, CHARLES (1801–1893)
• CLAY, FREDERIC (1838–1889)
• CLAY, HENRY (1777–1852)

clay-See also:

• SLATE (properly CLAY SLATE; in M. Eng. slat or sclat, from O. Fr. esclat, a small piece of wood used as a tile; esclater, to break into pieces, whence modern Fr. eclat, the root being seen also in Ger. schleissen, to split)

slate, and in the " growan " or See also:

• GRANITE (adapted from the Ital. granite, grained; Lat. granum, grain)

granite . Erubescite (q.v.), bornite, or horseflesh ore is much richer in copper than the ordinary pyrites, and contains 56 or 57% of copper . Tetrahedrite (q.v.), fahlerz, or See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey copper, contains from 30 to 48% of copper, with See also:

• ARSENIC (symbol As, atomic weight 75.0)

arsenic, See also:

• ANTIMONY (symbol Sb, atomic weight 120.2)

antimony, iron and sometimes See also:

• ZINC

zinc, silver or See also:

• MERCURY
• MERCURY (MERCU1uus)
• MERCURY (symbol Hg, atomic weight = 2oo)

mercury . Other copper minerals are percylite (PbCuC12(OH)2), boleite (3PbCuC12(OH)2, AgC1), stromeyerite ((Cu, Ag)2S}, cubanite (CuS, Fe2S3), See also:

• STANNITE

stannite (Cu2S, FeSnS3), tennantite'(3Cu2S, As2S3), emplectite (Cu2S, Bi2S3), wolfsbergite (Cu2S, Sb2S3), famatinite (3Cu2S, Sb2S5) and enargite (3Cu2S, As2S5) . For other minerals, see Compounds of Copper below .

Metallurgy.—Copper is obtained from its ores by three principal methods, which may be denominated—(r) the pyro-metallurgical or dry method, (2) the hydro-metallurgical or wet method, and (3) the electro-metallurgical method . The methods of working vary according to the nature of the ores treated and See also:

• LOCAL

local circumstances . The dry method, or ordinary smelting, cannot be profitably practised with ores containing less than 4% of copper, for which and for still poorer ores the wet See also:

• PROCESS

process is preferred . Copper Smelting.—We shall first give the See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general principles which underlie the methods for the dry extraction of copper, and then proceed to a more detailed discussion of the plant used . Since all sulphuretted copper ores (and these are of the most economic importance) are invariably contaminated with arsenic and antimony, it is necessary to eliminate these impurities, as far as possible, at a very See also:

• EARLY
• EARLY, JUBAL ANDERSON (1816-1894)

early See also:

• STAGE (Fr. 6/age; from Lat. stare, to stand)

stage . This is effected by calcination or roasting . The roasted ore is then smelted to a mixture of copper and iron sulphides, known as copper " matte " or " coarse-metal," which contains little or no arsenic, antimony or See also:

• SILICA

silica . The coarse-metal is now smelted, with See also:

• COKE (a northern English word, possibly connected with " colk," core)
• COKE, SIR EDWARD (1552-1634)
• COKE, SIR JOHN (1563-1644)
• COKE, THOMAS (1747-1814)

coke and siliceous fluxes (in See also:

• ORDER
• ORDER (through Fr. ordre, for earlier ordene, from Lat. ordo, ordinis, rank, service, arrangement; the ultimate source is generally taken to be the root seen in Lat. oriri, rise, arise, begin; cf. " origin ")
• ORDER, HOLY

order to slag off the irqn), and the product, consisting of an impure copper sulphide, is variously known as blue-metal," when more or less iron is still See also:

• PRESENT

present, " pimple-metal," when free copper and more or less copper oxide is present, or " fine " or " See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white-metal," which is a fairly pure copper sulphide, containing about 75% of the metal . This product is re-smelted to See also:

• FORM (Lat. forma)

form " coarse-copper," containing about 95% of the metal, which is then refined . Roasted ores may be smelted in reverberatory furnaces (English process), or in blast-furnaces (German or See also:

• SWEDISH

Swedish process) . The matte is treated either in reverberatory furnaces (English process), in blast furnaces (German process), or in converters (See also:

• BESSEMER
• BESSEMER, SIR HENRY (1813-1898)

Bessemer process) . The " See also:

• AMERICAN

American process " or " Pyritic smelting " consists in the See also:

• DIRECT

direct smelting of raw ores to matte in blast furnaces .

The plant in which the operations are conducted varies in different countries . But though this or that process takes its name from the See also:

• COUNTRY (from the Mid. Eng. contre or contrie, and O. Fr. cuntree; Late Lat. contrata, showing the derivation from contra, opposite, over against, thus the tract of land which fronts the sight, cf. Ger. Gegend, neighbourhood)

country in which it has been mainly See also:

• DEVELOPED

developed, this does not mean that only that process is there followed . The " English process " is made up of the following operations: (r) calcination; (2) smelting in reverberatory furnaces to form the matte; (3) roasting the matte; and (4) subsequent smelting in reverberatory furnaces to fine- or white-metal; (5) treating the fine-metal in reverberatory furnaces to coarse- or See also:

• BLISTER (a word found in many forms in Teutonic languages, cf. Ger. Blase; it is ultimately connected with the same root as in " blow," cf. " bladder ")

blister-copper, either with or without previous calcination; (6) refining of the coarse-copper . A shorter process (the so-called " direct process ") converts the fine-metal into refined copper directly . The " Welsh process " closely resembles the English method; the See also:

• MAIN (from the Aryan root which appears in " may " and " might," and Lat. magnus, great)
• MAIN (Lat. Moenus)

main difference consists in the enrichment of the matte by smelting with the See also:

• RICH, BARNABE (c. 1540-1617)
• RICH, CLAUDIUS JAMES (1787-1821)
• RICH, JOHN (1692-1761)
• RICH, PENELOPE, LADY (c. 1562–1607)
• RICH, RICHARD, 1ST BARON RICH (1490?-1567)

rich copper-bearing slags obtained in subsequent operations . The " German or Swedish process " is characterized by the introduction of blast-furnaces . It is made up of the following operations: (I) calcination, (2) smelting in blast-furnaces to form the matte, (3) roasting the matte, (4) smelting in blast-furnaces with coke and fluxes to " See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black- " or " coarse-metal," (5) refining the coarse-metal . The " Anglo-German Process " is a See also:

• COMBINATION (Lat. combinare, to combine)

combination of the two preceding, and consists in smelting the calcined ores in See also:

• SHAFT
• SHAFT (O. Eng., sceaft, from scafan, to shave; the word is common to Teutonic languages)

shaft furnaces, concentrating the matte in reverberatory furnaces, and smelting to coarse-metal in either . The impurities contained in coarse-copper are mainly iron, lead, zinc, See also:

• COBALT (symbol Co, atomic weight 59)

cobalt, See also:

• NICKEL
• NICKEL (symbol Ni, atomic weight 58.68 (0=16))

nickel, See also:

• BISMUTH

bismuth, arsenic, antimony, sulphur, See also:

• SELENIUM [symbol Se, atomic weight 79.2 (O=16)]

selenium and See also:

• TELLURIUM [Symbol Te, atomic weight 127.5 (0=16)]

tellurium . These can be eliminated by an oxidizing See also:

• FUSION

fusion, and slagging or volatilizing the products resulting from this operation, or by See also:

• ELECTROLYSIS (formed from Gr. Xbety, to loosen)

electrolysis (see below) . In the process of oxidation, a certain amount of cuprous oxide is always formed, which melts in with the copper and diminishes its softness and tenacity . It is, therefore, necessary to reconvert the oxide into the metal .

This is effected by stirring the molten metal with a See also:

• POLE (FAMILY)
• POLE, REGINALD (1500-1558)
• POLE, RICHARD DE LA (d. 1525)
• POLE, WILLIAM (1814—1900)

pole of green See also:

• WOOD, ANTHONY A2 (1632-1695)
• WOOD, JOHN GEORGE (1827—1889)
• WOOD, MRS HENRY [ELLEN] (1814—1887)
• WOOD, SEARLES VALENTINE (1798—188o)

wood (" poling "); the products which arise from the See also:

• COMBUSTION (from the Lat. comburere, to burn up)

combustion and See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation of the wood reduce the oxide to metal, and if the operation be properly conducted " tough-See also:

• PITCH
• PITCH, MUSICAL

pitch " copper, soft, malleable and exhibiting a lustrous silky fracture, is obtained . The surface of the molten metal is protected from oxidation by a layer of See also:

• ANTHRACITE (Gr. avOpaE, coal)

anthracite or See also:

• CHARCOAL

charcoal . ".See also:

• BEAN (a common Teutonic word, cf. Ger. Bohne)

Bean-shot " eopper is obtained by throwing the molten metal into hot water; if See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold water be used, " feathered-shot " copper is formed . " Rosette " copper is obtained as thin plates of a characteristic dark-red colour, by pouring water upon the surface of the molten metal, and removing the crust formed . " See also:

• JAPAN

Japan " copper is See also:

• PURPLE

purple-red in colour, and is formed by casting into ingots, weighing from six ounces to a See also:

• POUND
• POUND (2)—(a)

pound, and rapidly cooling by See also:

• IMMERSION (Lat. immersio, dipping),

immersion in water . The colour of these two varieties is due to a layer of oxide . " See also:

• TILE (0. Eng. tigel, Fr. tuile, connected with Lat. tegula)

Tile " copper is an impure copper, and is obtained by refining the first tappings . " Best-selected " copper is a purer variety . Calcination or Roasting and Calcining Furnaces.—The roasting should be conducted so as to eliminate as much of the arsenic and antimony as possible, and to leave just enough sulphur as is necessary to combine with all the copper present when the calcined ore is smelted . The process is effected either in heaps, stalls, shaft furnaces, reverberatory furnaces or muffle furnaces . See also:

• STALL (0. Eng. steall, stael, cf. Du. stal, Ger. and Swed. Stall, a common Teutonic word for a place, station, place for standing in; the root is the Indo-European std–, to stand, seen also in Latin stabulum, Greek vraO bs, and in stallion, an entire hors

Stall and heap roasting require considerable See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time, and can only be economically employed when the loss of the sulphur is of no consequence; they also occupy much space, but they have the See also:

• ADVANTAGE

advantage of requiring little See also:

• FUEL (O. Fr. feuaile, popular Lat. focalia, from focus, hearth, fire)

fuel and handling . Shaft furnaces are in use for ores rich in sulphur, and where it is desirable to convert the See also:

• WASTE (O. Fr. wast, guast, gast, gaste; Lat. vastus, vast, desolate)

waste gases into sulphuric acid .

Reverberatory roasting does not admit of the utilization of the waste gases, and requires fine ores and much labour and fuel; it has, however, the advantage of being rapid . Muffle furnaces are suitable for fine ores which are liable to decrepitate or See also:

• SINTER

sinter . They involve high cost in fuel and labour, but permit the utilization of the waste gases . Reverberatory furnaces of three types are employed in calcining copper ores: (i) fixed furnaces, with either See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand or See also:

• MECHANICAL

mechanical rabbling; (2) furnaces with movable beds; (3) furnaces with rotating working See also:

• CHAMBERS (the Fr. chambre, from Lat. camera, a room)
• CHAMBERS, EPHRAIM (d. 1740)
• CHAMBERS, GEORGE (1803-1840)
• CHAMBERS, ROBERT (18oz-1871)
• CHAMBERS, SIR WILLIAM (1726-1796)

chambers . Hand rabbling in fixed furnaces has been largely superseded by mechanical rabbling . Of mechanically rabbling furnaces we may mention the O'Harra modified by See also:

• ALLEN, BOG OF
• ALLEN, ETHAN (1739–1789)
• ALLEN, GRANT CHARLES GRANT BLAIRFINDIEI, (1848–1899)
• ALLEN, JAMES LANE (1850– )
• ALLEN, JOHN (1476–1534)
• ALLEN, or ALLEYN, THOMAS (1542-1632)
• ALLEN, WILLIAM (1532-1594)
• ALLEN, WILLIAM FRANCIS (183o-1889)

Allen-Brown, the Hixon, the See also:

• KELLER, ALBERT (1845- )
• KELLER, GOTTFRIED (1819-1890)
• KELLER, HELEN ADAMS (188o- )

Keller-Gaylord-See also:

• COLE, SIR HENRY (1808–1882)
• COLE, THOMAS (1801–1848)
• COLE, TIMOTHY (1852– )
• COLE, VICAT (1833–1893)

Cole, the Ropp, the See also:

• SPENCE, THOMAS (1750-1814)

Spence, the Wethey, the See also:

• PARKES, SIR HARRY SMITH (1828-1885)
• PARKES, SIR HENRY (1815–1896)

Parkes, See also:

• PEARCE, CHARLES SPRAGUE (1851– )

Pearce's " See also:

• TURRET (from O. Fr. tourette, diminutive of tour, tower, mod. Fr. tourelle)

Turret " and Brown's " Horseshoe " furnaces . See also:

• BLAKE, EDWARD (1833– )
• BLAKE, ROBERT (1599-1657)
• BLAKE, WILLIAM (1757-1827)

Blake's and See also:

• BRUNTON, MARY (1778–1818)

Brunton's furnaces are reverberatory furnaces with a movable See also:

• BED
• BED (a common Teutonic word, cf. German Bett, probably connected with the Indo-European root bhodh, seen in the Lat. fodere, to dig; so " a dug-out place " for safe resting, or in the same sense as a garden " bed ")

bed . Furnaces with rotating working chambers admit of continuous working; the fuel and labour See also:

• COSTS

costs are both See also:

• LOW, SETH (1850- )
• LOW, WILL HICOK (1853- )

low . In the White-See also:

• HOWELL, JAMES (c. 1594-1666)

Howell revolving furnace with lifters—a modification of the Oxland—the ore is fed and discharged in a continuous stream . The See also:

• BRUCKNER, ANTON (1824–1896)

Bruckner See also:

• CYLINDER (Gr. KvAwSpos, from KvXivaety, to roll)

cylinder resembles the Elliot and See also:

• RUSSELL (FAMILY)
• RUSSELL, ISRAEL COOK (1852- )
• RUSSELL, JOHN (1745-1806)
• RUSSELL, JOHN (d. 1494)
• RUSSELL, JOHN RUSSELL, 1ST EARL (1792-1878)
• RUSSELL, JOHN SCOTT (1808–1882)
• RUSSELL, LORD WILLIAM (1639–1683)
• RUSSELL, SIR WILLIAM HOWARD
• RUSSELL, THOMAS (1762-1788)
• RUSSELL, WILLIAM CLARK (1844– )

Russell black ash furnace; its cylinder tapers slightly towards each end, and is generally i8 ft. See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long by 8 ft . 6 in. in its greatest See also:

• DIAMETER (from the Cr. &a, through, µErpov, measure)

diameter . Its See also:

• CHARGE
• CHARGE (through the Fr. from the Late Lat. carricare, to load in a carrus or wagon; cf. " cargo ")

charge of from 8 to 12 tons of ore or concentrates is slowly agitated at a See also:

• RATE

rate of three revolutions a See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute, and in from 24 to 36 See also:

• HOURS, CANONICAL

hours it is reduced from say 40 or 35 % to 7 % of sulphur .

The ore is under better See also:

• CONTROL (Fr. contrdle, older form contre rolle, from Med. Lat. contra-rotulus, a counter roll or copy of a document used to check the original; there is no instance in English of the use of " control " in this, its literal, meaning)

control than is possible with the continuous feed and See also:

• DISCHARGE (adapted from the O. Fr. discharge, modern decharge, from a med. Lat. discargare, to unload, dis- and earn care, to load, cf. " charge ")

discharge, and when sufficiently roasted can be passed red-hot to the reverberatory furnace . These advantages compensate for the See also:

• WEAR

wear and See also:

• TEAR

tear and the cost of moving the heavy dead-weight . Shaft calcining furnaces are available for fine ores and permit the recovery of the sulphur . They are square, oblong or circular in See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

section, and the interior is fitted with See also:

• HORIZONTAL

horizontal or inclined plates or prisms, which regulate the fall of the ore . In the Gerstenhoffer and Hasenclever-Helbig furnaces the fall is retarded by prisms and inclined plates . In other furnaces the ore rests on a series of horizontal plates, and either remains on the same See also:

• PLATE

plate throughout the operation (011ivier and Perret furnace), or is passed from plate to plate by hand (Maletra), or by mechanical means (Spence and M'Dougall) . The M'Dougall furnace is turret-shaped, and consists of a series of circular hearths, on which the ore is agitated by rakes attached to revolving arms and made to fall from See also:

• HEARTH (a word which appears in various forms in several Teutonic languages, cf. Dutch haard, German Herd, in the sense of " floor ")

hearth to hearth . It has been modified by Herreshoff, who uses a large hollow revolving central shaft cooled by a current of air . The shaft is provided with sockets, into which movable arms with their rakes are readily dropped . The See also:

• PETER
• PETER (Lat. Petrus from Gr. irfpos, a rock, Ital. Pietro, Piero, Pier, Fr. Pierre, Span. Pedro, Ger. Peter, Russ. Petr)
• PETER (PEDRO)
• PETER, EPISTLES OF
• PETER, ST

Peter Spence type of calcining furnace has been followed in a large number of inventions . In some the rakes are attached to rigid frames, with a reciprocating See also:

• MOTION (Lat. motio, from movere, to move)
• MOTION, LAWS OF

motion; in others to See also:

• CROSS

cross-bars moved by revolving chains . Some ofthese furnaces are straight, others circular .

Some have only one hearth, others three . This and the previous type of furnace, owing to their large capacity, are at present in greatest favour . The M'Dougall-Herreshoff, working on ores of over 30% of sulphur, requires no fuel; but in furnaces of the reverberatory type fuel must be used, as an excess of air enters through the slotted sides and the hinged doors which open and shut frequently to permit of the passage of the rakes . The See also:

• CONSUMPTION (Lat. consumere)

consumption of fuel, however, does not exceed r of See also:

• COAL

coal to ro of ore . The quantity of ore which these large furnaces, with a hearth See also:

• AREA

area as See also:

• GREAT

great as 2000 ft. and over, will roast varies from 40 to 6o tons a See also:

• DAY (O. Eng. dreg, Ger. Tag; according to the New English Dictionary, " in no way related to the Lat. dies")
• DAY, JOHN (1574-1640?)
• DAY, THOMAS (1748-1789)

day . Shaft calcining furnaces like the Gerstenhoffer, Hasenclever, and others designed for burning pyrites fines have not found favour in See also:

• MODERN

modern copper See also:

• WORKS

works . The Fusion of Ores in Reverberatory and See also:

• CUPOLA (Ital., from Lat. cupula, small cask or vault, cupa, tub)

Cupola Furnaces.—After the ore has been partially calcined, it is smelted to See also:

• EXTRACT (from Lat. extrahere, to draw out)

extract its earthy matter and to concentrate the copper with See also:

• PART

part of its iron and sulphur into a matte . In reverberatory furnaces it is smelted by fuel in a fireplace, See also:

• SEPARATE

separate from the ore, and in cupolas the fuel, generally coke, is in direct contact with the ore . When See also:

• SWANSEA

Swansea was the centre of the copper-smelting See also:

• INDUSTRY (Lat. industria, from indu-, a form of the pre, position in, and either stare, to stand, or struere, to pile up)

industry in See also:

• EUROPE

Europe, many varieties of ores from different mines were smelted in the same furnaces, and the Welsh reverberatory furnaces were used . To-day more than eight-tenths of the copper ores of the world are reduced to impure copper bars or to fine copper at the mines; and where the See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character of the ore permits, the cupola furnace is found more economical in both fuel and labour than the reverberatory . The Welsh method finds adherents only in See also:

• WALES (Cymru, Gwalia, Cambria)

Wales and Chile . In See also:

• AMERICA

America the usual method is to roast ores or concentrates so that the matte yielded by either the reverberatory or cupola furnace will run from 45 to 50% in copper, and then to See also:

• TRANSFER (from Lat. transferre, to bear across, carry over)

transfer to the Bessemer converter, which blows it up to 99 % .

In See also:

• BUTTE
• BUTTE (O. Fr. butte, a hillock or rising ground)

Butte, See also:

• MONTANA

Montana, reverberatories have in the past been preferred to cupola furnaces, as the charge has consisted mainly of fine roasted concentrates; but the cupola is gaining ground there . At the See also:

• BOSTON
• BOSTON, THOMAS (1676-1732)

Boston and Great Falls (Montana) works tilting reverberatories, modelled after open hearth See also:

• STEEL, FLORA ANNIE (1847– )

steel furnaces, were first erected; but they were found to possess objectionable features . Now both these and the See also:

• EGG (O.E. aeg, cf. Ger. Ei, Swed. aegg, and prob. Gr. u,ov, Lat. ovum)
• EGG, AUGUSTUS LEOPOLD (1816-1863)

egg-shaped reverberatories are being abandoned for furnaces as long as 43 ft . 6 in. from See also:

• BRIDGE

bridge to bridge and of a width of 15 ft . 9 in. heated by See also:

• GAS

gas, with re-generative checker See also:

• WORK

work at each end, and fed with ore or See also:

• CON

con, centrates, red-hot from the calciners, through a See also:

• LINE

line of hoppers suspended above the roof . Furnaces of this See also:

• SIZE

size See also:

• SMELT (Osmerus eperlanus; Fr. eperlan; Scotch sparling or spirling)

smelt 200 tons of charge a day . But even when the old type of reverberatory is preferred, as at the Argo works, at See also:

• DENVER

Denver, where rich gold. and silver-bearing copper matte is made, the growth of the furnace in size has been steady . See also:

• RICHARD
• RICHARD (d. 1184)
• RICHARD, FRANCOIS MARIE BENJAMIN (18,9-1908)
• RICHARD, HENRY (1812-1888)
• RICHARD, ST

Richard Pearce's reverberatories in 1878 had an area of hearth of 15 ft. by 9 ft . 8 in., and smelted 12 tons of cold charge daily, with a consumption of i ton of coal to 2.4 tons of ore . In r900 the furnaces were 35 ft. by 16 ft., and smelt 5o tons daily of hot ore, with the consumption of i ton of coal to 3.7 tons of ore . The See also:

• HOME
• HOME, DANIEL DUNGLAS (1833-1886)
• HOME, EARLS OF

home of cupola smelting was See also:

• GERMANY
• GERMANY (Ger. Deutschland)

Germany, where it has never ceased to make steady progress . In See also:

• MANSFELD

Mansfeld See also:

• BRICK (derived according to some etymologists from the Teutonic bricke, a disk or plate; but more authoritatively, through the French brique, originally a " broken piece," applied especially to bread, and so to clay, from the Teutonic brikan, to break)

brick cupola furnaces are without a See also:

• RIVAL

rival in size, equipment and performance .

They are See also:

• ROUND (O. Fr. rond, Lat. rotundus, the Fr. is the source also of Du. rond; Ger., Swed., Dan. and Nor. rond)

round stacks, designed on the See also:

• MODEL (0. Fr. modelle, mod. modele; It. modello, pattern, mould; from Lat. modus, measure, standard)

model of iron blast furnaces, 29 ft. high, fed mechanically, and provided with stoves to heat the blast by the furnace gases . The low percentage of sulphur in the roasted ore is little more than enough to produce a matte of 40 to 45%, and therefore the escaping gases are better fitted than those of most copper cupola furnaces for burning in a See also:

• STOVE

stove . But as the slag carries on an See also:

• AVERAGE

average 46 % of silica, it is only through the utmost skill that it can be made to run as low on an average as o•3 % in copper oxide . As the matte contains on an average o•2% of silver, it is still treated by the Ziervogel wet method of extraction, the management dreading the loss which might occur in the Bessemer process of concentration, applied as preliminary to electrolytic separation . Blast furnaces of large size, built of brick, have been constructed for treating the richest aDd more silicious ores of Rio Tinto, and the Rio Tinto See also:

• COMPANY

Company has introduced converters at the mine . This method of extraction contrasts favourably in time with the leaching process, which is so slow that over ro,000,000 tons of ore are always under treatment on the immense leaching floors of the company's works in See also:

• SPAIN
• SPAIN (Espana)

Spain . In the See also:

• UNITED

United States the cupola has undergone a See also:

• RADICAL (Lat. radix, a root)

radical modification in being built of water-jacketed sections . The first water-jacketed cupola which came into general use was a circular inverted See also:

• CONE (Gr. Kwvos)

cone, with a slight See also:

• TAPER (probably of Celtic origin, cf. Irish tapar, Welsh tampr, taper, torch)

taper, of 36 inches diameter at the tuyeres, and composed of an See also:

• OUTER

outer and an inner metal See also:

• SHELL
• SHELL (O. Eng. scell, scyll, cf. Du. sceel, shell, Goth. skalja, tile; the word means originally a thin flake,. cf. Swed. skalja, to peel off; it is allied to " scale " and " skill," from a root meaning to cleave, divide, separate)

shell, between which water circulated . As greater size has been demanded, See also:

• OVAL (Lat. ovum, egg)

oval and rectangular furnaces—as large as 18o in. by 56 in. at the tuyereshave been built in sections of See also:

• CAST (from the verb meaning " to throw "; the word is Scand. in origin, cf. Dan. kaste, and Swed. kasta; " cast " in Middle Eng. took the place of the A.S. weor pan, cf. Ger. werf en)

cast or See also:

• SHEET

sheet iron or steel . A single section can be removed and replaced without entirely emptying the stack, as a shell of congealed slag always coats the inner surface of the jacket . The largest furnaces are those of the Boston & Montana Company at Great Falls, Montana, which have put through 500 tons of charge daily, pouring their melted slag and matte into large See also:

• WELLS
• WELLS, CHARLES JEREMIAH (1798?–1879)
• WELLS, DAVID AMES (1828—1898)
• WELLS, HERBERT GEORGE (1866— )
• WELLS, SIR THOMAS SPENCER, 1ST BART

wells of ro ft. in diameter . A combined brick- and water-cooled furnace has been adopted by the Iron See also:

• MOUNTAIN (0. Fr. montaigne; popular Lat. montanea, an adjectival form from the classical mons, montis, whence Eng. " mount," a form usually used along with the name of an individual mountain, e.g. Mt Everest)
• MOUNTAIN, THE (La Montagne)

Mountain Company at See also:

• KESWICK

Keswick, Cal., for matte concentration .

In it the cooling is effected by water pipes, interposed horizontally between the layers of bricks . The Mt . See also:

• LYELL, SIR CHARLES (1797-1875)

Lyell smelting works in See also:

• TASMANIA

Tasmania, which are of special See also:

• INTEREST

interest, will be referred to later . (See Pyritic Smelting below.) Concentrating Matte to Copper in the Bessemer Converter.—As soon as the pneumatic method of decarburizing See also:

• PIG
• PIG (a word of obscure origin, connected with the Low Ger. and Dut. word of the same meaning, bigge)

pig iron was accepted as practicable, experiments were made with a view to Bessemerizing copper ores and mattes . One of the earliest and most exhaustive series of experiments was made on Rio Tinto ores at the See also:

• JOHN
• JOHN (1167–1216)
• JOHN (1290-c. 1320)
• JOHN (1296-1346)
• JOHN (1371–1419)
• JOHN (1468-1532)
• JOHN (1801-1873)
• JOHN (Heb. llni')
• JOHN (ZAPOLYA) (1487-1540)
• JOHN, 4TH MARQUESS OF TWEEDDALE (c. 1695-1762)
• JOHN, DON (1545-1578)
• JOHN, DON (1629–1679)
• JOHN, GOSPEL OF ST
• JOHN, or HAYS (1513–1571)
• JOHN, THE APOSTLE
• JOHN, THE EPISTLES OF

John Brown works by John Hollway, with the aim of both smelting the ore and concentrating the matte in the same furnace, by the heat evolved through the oxidation of their sulphur and iron . Experiments along the same lines were made by See also:

• FRANCIS
• FRANCIS (FRarrcols) OF SALES, ST (1567-1622)
• FRANCIS (Lat. Franciscus, Ital. Francesco, Span. Francisco, Fr. Francois, Ger. Franz)
• FRANCIS, SIR PHILIP (174o-1818)

Francis Bawden at Rio Tinto and See also:

• CLAUDE, JEAN (1619-1687)

Claude Vautin in Australia . The difficulty of effecting this See also:

• DOUBLE
• DOUBLE (from the Mid. Eng. duble, the form which gives the present pronunciation, through the Old Er. duble, from Lat. duplus, twice as much)

double See also:

• OBJECT

object in one operation was so great that in subsequent experiments the aim was merely to concentrate the matte to metallic copper in converters of the Bessemer type . The concentration was effected without any embarrassment till metallic copper commenced to separate and chill in the bottom tuyeres . To meet this obstacle P . Mantles proposed elevated See also:

• SIDE
• SIDE (mod. Eski Adalia)

side tuyeres, which could be kept clear by punching through See also:

• GATES, HORATIO (1728-1806)

gates in a See also:

• WIND
• WIND (a common Teut. word, cognate with Skt. vats, Lat. ventus, cf. " weather," to be of course distinguished from to " wind," to coil or twist, O.Eng. windan, cf. "wander," "wend," &c.)

wind See also:

• BOX
• BOX (Gr. irl or, Lat. buxus, box-wood; cf. 2r6Eir, a pyx)

box . His invention was adopted by the Vivians, at the Eguilles works near Sargues, See also:

• VAUCLUSE

Vaucluse, See also:

• FRANCE
• FRANCE, ANATOLE (1844– )

France, and at See also:

• LEGHORN (Ital. Livorno, Fr. Livourne)

Leghorn in See also:

• ITALY
• ITALY (Italia)

Italy . But the greatest expansion of this method has been in the United States, where more than 400,000,000 lb. of copper are annually made in Bessemer converters .

Vessels of several designs are used—some modelled exactly after steel converters, other See also:

• BARREL (a word of uncertain origin common to Romance languages; the Celtic forms, as in the Gaelic baraill, are derived from the English)

barrel-shaped, but all with side tuyeres elevated about so in. above the level of the bottom lining . Practice, however, in treating copper matte differs essentially from the treatment of pig iron, inasmuch as from 20 to 30% of iron must be eliminated as slag and an See also:

• EQUIVALENT

equivalent quantity of silica must be supplied . The only See also:

• PRACTICAL

practical mode of doing this, as yet devised, is by lining the converter with a silicious mixture . This is so rapidly consumed that the converters must be cooled and partially relined after 3 to 6 charges, dependent on the iron contents of the matte . When available, a silicious rock containing copper or the See also:

• PRECIOUS (O. Fr. precios, mod. precieux, Lat. pretiosus, of high value or price, pretium)

precious metals is of course preferred to barren lining . The material for lining, and the frequent replacement thereof, constitute the principal expense of the method . The other items of cost are labour, the quantity of which depends on the mechanical appliances provided for handling the converter shells and inserting the lining; and the blast, which in barrel-shaped converters is low and in See also:

• VERTICAL (from Lat. vertex, highest point)

vertical converters is high, and which varies therefore from 3 to 15 lb to the square See also:

• INCH (O. Eng. ynce from Lat. uncia, a twelfthpart; cf. " ounce," and see As)

inch . The quantity of air consumed in a converter which will See also:

• BLOW, JOHN (1648-1708)

blow up about 35 tons of matte per day is about 3000 cub. ft. per minute . The operation of raising a charge of 50% matte to copper usually consists of two blows . The first blow occupies about 25 minutes, and oxidizes all but a small quantity of the iron and some of the sulphur, raisingthe product to white metal . The slag is then poured and skimmed, the blast turned on and converter retilted . During the second blow the sulphur is rapidly oxidized, and the charge reduced to metal of 99% in from 30 to 40 minutes .

Little or no slag results from the second blow . That from the first blow contains between 1% and 2% of copper, and is usually poured from ladles operated by an electric See also:

• CRANE (in Dutch, Kraan; O. Ger. Kraen; cognate, as also the Lat. grus, and consequently the Fr. grue and Span. grulla, with the Gr. dpavos)
• CRANE, STEPHEN (1870-1900)
• CRANE, WALTER (1845– )
• CRANE, WILLIAM HENRY (1845– )

crane into a reverberatory, or into the settling well of the cupola . The matte also, in all economically planned works, is conveyed, still molten, by electric See also:

• CRANES (so called from the resemblance to the long neck of the bird, cf. Gr. 'y pavor, Fr. grue)

cranes from the furnace to the converters . When lead or zinc is not present in notable quantity, the loss of the precious metals by volatilization is slight, but more than 5% of these metals in the matte is prohibitive . Under favourable conditions in the larger works of the United States the cost of converting a 50% matte to metallic copper is generally understood to be only about 15w to 3- of a cent per lb. of refined copper . Pyritic Smelting.—The heat generated by the oxidation of iron and sulphur has always been used to maintain combustion in the kilns or stalls for roasting pyrites . Pyritic smelting is a development of the See also:

• RUSSIAN

Russian engineer Semenikov's treatment (proposed in 1866) of copper matte in a Bessemer converter . Since John Hollway's and other early experiments of See also:

• LAWRENCE
• LAWRENCE (LAURENTIUS, LORENZO), ST
• LAWRENCE, AMOS (1786—1852)
• LAWRENCE, AMOS ADAMS (1814–1886)
• LAWRENCE, GEORGE ALFRED (1827–1876)
• LAWRENCE, JOHN LAIRD MAIR LAWRENCE, 1ST BARON (1811-1879)
• LAWRENCE, SIR HENRY MONTGOMERY (1806–1857)
• LAWRENCE, SIR THOMAS (1769–1830)
• LAWRENCE, STRINGER (1697–1775)

Lawrence See also:

• AUSTIN
• AUSTIN, ALFRED
• AUSTIN, JOHN (179o-1859)
• AUSTIN, SARAH (1793-1867)
• AUSTIN, STEPHEN FULLER (1793-1836)

Austin and See also:

• ROBERT
• ROBERT (1275—1343)
• ROBERT, HUBERT (1753-1808)
• ROBERT, LOUIS LEOPOLD (1794-1835)

Robert Sticht, no serious attempts have been made to utilize the heat escaping from a converting See also:

• VESSEL (O. Fr. vaissel, from a rare Lat. vascellum, dim. of vas, vase, urn)

vessel in smelting ore and matte either in the same apparatus or in a separate furnace . But considerable progress has been made in smelting highly sulphuretted ores by the heat of their own oxidizable constituents . At Tilt See also:

• COVE

Cove, See also:

• NEWFOUNDLAND

Newfoundland, the Cape Copper . Company smelted copper ore, with just the proper proportion of sulphur, iron and silica, successfully without any fuel, when once the initial charge had been fused with coke . The furnaces used were of ordinary See also:

• DESIGN (Fr. desiin, drawing; Lat. designare, to mark out)

design and built of brick .

Lump ore alone was fed, and the resulting matte showed a concentration of only 3 into i . When, however, a hot blast is used on highly sulphuretted copper ores, a concentration of 8 of ore into 1 of matte is obtained, with a consumption of less than one-third the fuel which would be consumed in smelting the charge had the ore been previously calcined . A great impetus to pyritic smelting was given by the investigations of W . L . Austin, of Denver, See also:

• COLORADO

Colorado, and both at See also:

• LEADVILLE

Leadville and Silverton raw ores are successfully smelted with as low a fuel consumption as 3 of coke to too of charge . Two types of pyritic smelting may be distinguished: one, in which the operation is solely sustained by the combustion of the sulphur in the ores, without the assistance of fuel or a hot blast; the other in which the operation is accelerated by fuel, or a hot blast, or both . The largest See also:

• ESTABLISHMENT (0. Fr. establissement, Fr. etablissement, late Norm. Fr. establishement, from O. Fr. establir, Fr. etablir, Lat. stabilire, to make stable)

establishment in which advantage is taken of the self-contained fuel is at the smelting works of the Mt . Lyell Company, Tasmania . There the blast is raised from 600° to 700 F. in stoves heated by extraneous fuel, and the raw ore smelted with only 3 % of coke . The ore is a compact iron pyrites containing copper 2.5%, silver 3'83 oz., gold 0.139 oz . It is smelted raw with hot blast in cupola furnaces, the largest being 210 in. by 40 in . The resulting matte runs 25% .

This is reconcentrated raw in hot-blast cupolas to 55%, and blown directly into copper in converters . Thus these ores, as heavily charged with sulphur as those of the Rio Tinto, are speedily reduced by three operations and without roasting, with a saving of 97.6% of the copper, 93'2% of the silver and 93.6% of the gold . Pyritic smelting has met with a varying economic success . According to See also:

• HERBERT (FAMILY)
• HERBERT, GEORGE (1593-1633)
• HERBERT, HENRY WILLIAM
• HERBERT, SIR THOMAS (1606-1682)

Herbert See also:

• LANG, ANDREW (1844— )
• LANG, KARL HEINRICH, RITTER VON (1764-1835)

Lang, its most prominent See also:

• CHANCE (through the O. Fr. cheance, from the Late Lat. cadentia, things happening, from cadere, to fall out, happen; cf. " case ")

chance of success is in localities where fuel is dear, and the ores contain precious metals and sufficient sulphides and arsenides to render profitable dressing unnecessary . The Nicholls and See also:

• JAMES
• JAMES (Gr. 'IlrKw,l3or, the Heb. Ya`akob or Jacob)
• JAMES (JAMES FRANCIS EDWARD STUART) (1688-1766)
• JAMES, 2ND EARL OF DOUGLAS AND MAR(c. 1358–1388)
• JAMES, DAVID (1839-1893)
• JAMES, EPISTLE OF
• JAMES, GEORGE PAYNE RAINSFOP
• JAMES, HENRY (1843— )
• JAMES, JOHN ANGELL (1785-1859)
• JAMES, THOMAS (c. 1573–1629)
• JAMES, WILLIAM (1842–1910)
• JAMES, WILLIAM (d. 1827)

James Process.—Nicholls and James have applied, very ingeniously, well-known reactions to the refining of copper, raised to the grade of white metal . This process is practised by the Cape Copper and Elliot Metal Company . A portion of the white metal is calcined to such a degree of oxidation that when fused with the unroasted portion, the reaction between the See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen in the roasted matte and the sulphur in the raw material liberates the metallic copper . The metal is so pure that it can be refined by a continuous operation in the same furnace . Wet Methods for Copper Extraction.—Wet methods are only employed for low grade ores (under favourable circumstances ore containing from 4 to 1% of copper has admitted of economic treatment), and for gold and silver bearing metallurgical products . The fundamental principle consists in getting the ore into a solution, from which the metal can be precipitated . The ores of any economic importance contain the copper either as oxide, carbonate, sulphate or sulphide . These compounds are got into solution either as chlorides or sulphates, and from either of these salts the metal can be readily obtained .

Ores in which the copper is present as oxide or carbonate are soluble in sulphuric or hydrochloric acids, ferrous chloride, ferric sulphate,ammoniacal compounds and See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium thiosulphate . Of these solvents, only the first three are of economic importance . The choice of sulphuric or hydrochloric acid depends mainly upon the cost, both acting with about the same rapidity; thus if a Leblanc soda factory is near at hand, then hydrochloric acid would most certainly be employed . Ferrous chloride is not much used; the See also:

• DOUGLAS
• DOUGLAS, GAVIN (1474?-1522)
• DOUGLAS, JOHN (1721—1807.)
• DOUGLAS, SIR CHARLES
• DOUGLAS, SIR HOWARD
• DOUGLAS, STEPHEN ARNOLD (18,3–1861)

Douglas-See also:

• HUNT, ALFRED WILLIAM (183o-1896)
• HUNT, HENRY (1i73-1835)
• HUNT, HENRY JACKSON (1819-1889)
• HUNT, JAMES HENRY LEIGH (1784-1859)
• HUNT, ROBERT (1807-1887)
• HUNT, THOMAS STERRY (1826-1892)
• HUNT, WILLIAM HENRY (1790—1864)
• HUNT, WILLIAM HOLMAN (1827-1910)
• HUNT, WILLIAM MORRIS (1824-1879)

Hunt process uses a mixture of See also:

• SALT (a common Teutonic word, cf. Dutch zout, Ger. Salz, Scand. salt; cognate with Gr. &Xs, Lat. sal)
• SALT, SIR TITUS, BART

salt and ferrous sulphate which involves the formation of ferrous chloride, and the new Douglas-Hunt process employs sulphuric acid in which ferrous chloride is added after leaching . Sulphuric acid may be applied as such on the ores placed in lead, brick, or See also:

• STONE
• STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
• STONE, CHARLES POMEROY (1824-1887)
• STONE, EDWARD JAMES (1831-1897)
• STONE, FRANK (1800-1859)
• STONE, GEORGE (1708—1764)
• STONE, LUCY [BLACKWELL] (1818-1893)
• STONE, MARCUS (184o— )
• STONE, NICHOLAS (1586-1647)

stone chambers; or as a mixture of sulphur dioxide, nitrous fumes (generated from Chile See also:

• SALTPETRE (from the Lat. sal, salt, Petra, a rock)

saltpetre and sulphuric acid), and See also:

• STEAM
• STEAM (0. Eng. steam, vapour, smoke, cf. Du. steam; the origin is unknown)

steam, which permeates the ore resting on the false bottom of a brick chamber . When most of the copper has been converted into the sulphate, the ore is lixiviated . Hydrochloric acid is applied in the same way as sulphuric acid; it has certain advantages of which the most important is that it does not admit the formation of basic salts; its See also:

• CHIEF (from Fr. chef, head, Lat. caput)

chief disadvantage is that it dissolves the oxides of iron, and accordingly must not be used for highly ferriferous ores . The solubility of copper carbonate in ferrous chloride solution was pointed out by Max Schaffner in 1862, and the subsequent recognition of the solubility of the oxide in the same solvent by James Douglas and Sterry Hunt resulted in the " Douglas-Hunt " process for the wet extraction of copper . Ferrous chloride decomposes the copper oxide and carbonate with the formation of cuprous and cupric chlorides (which remain in solution), and the precipitation of ferrous oxide, carbon dioxide being simultaneously liberated from the carbonate . In the See also:

• ORIGINAL

original form of the Douglas-Hunt process, ferrous chloride was formed by the interaction of sodium chloride (common salt) with ferrous sulphate (green See also:

• VITRIOL

vitriol), the sodium sulphate formed at the same time being removed by See also:

• CRYSTALLIZATION

crystallization . The ground ore was stirred with this solution at 7o° C. in wooden tubs until all the copper was dissolved . The liquor was then filtered from the iron oxides, and the filtrate treated with scrap iron, which precipitated the copper and reformed ferrous chloride, which could be used in the first stage of the process .

The advantage of this method rests chiefly on the small amount of iron required; but its disadvantages are that any silver present in the ores goes into solution, the formation of basic salts, and the difficulty of filtering from the iron oxides . A modification of the method was designed to remedy these defects . The ore is first treated with dilute sulphuric acid, and then ferrous or See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium chloride added, thus forming copper chlorides . If calcium chloride be used the precipitated calcium sulphate must be removed by filtration . Sulphur dioxide is then blown in, and the precipitate is treated with iron, which produces metallic copper, or See also:

• MILK (0. Eng. meoluc; from a common Indo-European root, cf. Lat. mulgere, Gr. ?t dXyetv)

milk of See also:

• LIME
• LIME (O. Eng. lim, Lat. limes, mud, from linere, to smear)

lime, which produces cuprous oxide . Hot air is blown into the filtrate, which contains ferrous or calcium chlorides, to expel the excess of sulphur dioxide, and the liquid can then be used again . In this process (" new Douglas-Hunt") there are no iron oxides formed, the silver is not dissolved, and the quantity of iron necessary is relatively small, since all the copper is in the cuprous See also:

• CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition . It is not used in the treatment of ores, but finds application in the case of calcined argentiferous lead and copper mattes . The precipitation of the copper from the solution, in which it is present as sulphate, or as cuprous and cupric chlorides, is generally effected by metallic iron . Either wrought, pig, iron sponge or iron bars are employed, and it is important to See also:

• NOTICE

notice that the form in which the copper is precipitated, and also the time taken for the separation, largely depend upon the condition in which the iron is applied . Spongy iron acts most rapidly, and after this follow iron turnings and then sheet clippings . Other precipitants such as sulphuretted hydrogen and solutions of sulphides, which precipitate the copper as sulphides, and milk of lime, which gives copper oxides, have not met with commercial success .

When using iron as the precipitant, it is desirable that the solution should be as neutral as possible, and the quantity of ferric salts present should be reduced to a minimum; otherwise, a certain amount of iron would be used up by the free acid and in reducing the ferric salts . Ores in which the copper is present as sulphate are directly lixiviated and treated with iron . Mine waters generally contain the copper in this form, and it is extracted by conducting the waters along troughs fitted with iron gratings . The wet extraction of metallic copper from ores in which it occurs as the sulphide, may be considered to involve the following operations: (1) See also:

• CONVERSION (Lat. conversio, from convertere, to turn or ,change)

conversion of the copper into a soluble form, (2) dissolving out the soluble copper salt, (3) the precipitation of the copper . Copper sulphide may be converted either into the sulphate, which is soluble in water; the oxide, soluble in sulphuric or hydrochloric acid; cupric chloride, soluble in water; or cuprous chloride, which is soluble in solutions of metallic chlorides . The conversion into sulphate is generally effected by the oxidizing processes of weathering, calcination, heating with iron nitrate or ferric sulphate . It may also be accomplished by calcination with ferrous sulphate, or other easily decomposable sulphates, such as See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium sulphate . Weathering is a very slow, and, therefore, an expensive process; moreover, the entire conversion is only accomplished after a number of years . Calcination is only advisable for ores which contain relatively much iron pyrites and little copper pyrites . Also, however slowly the calcination may be conducted, there is always more or less copper sulphide See also:

• LEFT

left unchanged, and some copper oxide formed . Calcination with ferrous sulphate converts all the copper sulphide into sulphate . Heap roasting has been successfully employed at Agordo, in the Venetian See also:

• ALPS

Alps, and at Majdanpek in See also:

• SERVIA

Servia .

Josef Perino's process, which consists in heating the ore with iron nitrate to 500-1500 C., is said to possess several advantages, but it has not been applied commercially . Ferric sulphate is only used as an See also:

• AUXILIARY (from Lat. auxilium, help)

auxiliary to the weathering process and in an electrolytic process . The conversion of the sulphide into oxide is adopted where the Douglas-Hunt process is employed, or where hydrochloric or sulphuric acids are cheap . The calcination is effected in reverberatory furnaces, or in muffle furnaces, if the sulphur is to be recovered . Heap, stall or shaft furnace roasting is not very satisfactory, as it is very difficult to transform all the sulphide into oxide . The conversion of copper sulphide into the chlorides may be accomplished by calcining with common salt, or by treating the ores with ferrous chloride and hydrochloric acid or with ferric chloride . The dry way is best; the wet way is only employed when fuel is very dear, or when it is absolutely necessary that no noxious vapours should See also:

• ESCAPE (in mid. Eng. eschape or escape, from the O. Fr. eschapper, modern echapper, and escaper, low Lat. escapium, from ex, out of, and cappa, cape, cloak; cf. for the sense development the Gr. iichueoOat, literally to put off one's clothes, hence to sli

escape into the atmosphere . The dry method consists in an oxidizing roasting of the ores, and a subsequent chloridizing roasting with either common salt or Abraumsalz in reverberatory or muffle furnaces . The bulk of the copper is thus transformed into cupric chloride, little cuprous chloride being obtained . This method had been long proposed by See also:

• WILLIAM
• WILLIAM (1143-1214)
• WILLIAM (1227-1256)
• WILLIAM (1J33-1584)
• WILLIAM (A.S. Wilhelm, O. Norse Vilhidlmr; O. H. Ger. Willahelm, Willahalm, M. H. Ger. Willehelm, Willehalm, Mod.Ger. Wilhelm; Du. Willem; O. Fr. Villalme, Mod. Fr. Guillaume; from " will," Goth. vilja, and " helm," Goth. hilms, Old Norse hidlmr, meaning
• WILLIAM (c. 1130-C. 1190)
• WILLIAM, 13TH

William Longmaid, Max Schaffner, Becchi and See also:

• HAUPT, MORITZ (1808—1874)

Haupt, but was only introduced into See also:

• ENGLAND
• ENGLAND, THE CHURCH OF

England by the labours of William See also:

• HENDERSON
• HENDERSON, ALEXANDER (1583-1646)
• HENDERSON, EBENEZER (1784-1858)
• HENDERSON, GEORGE FRANCIS ROBERT (1854-1903)
• HENDERSON, JOHN (1747-1785)

Henderson, J . A . See also:

• PHILLIPS
• PHILLIPS, ADELAIDE (1833-1882)
• PHILLIPS, EDWARD (163o-1696)
• PHILLIPS, JOHN (1800—1874)
• PHILLIPS, SAMUEL (1814—1854)
• PHILLIPS, STEPHEN (1868– )
• PHILLIPS, THOMAS (1770-1845)
• PHILLIPS, WENDELL (1811-1884)

Phillips and others .

The wet method is employed at Rio Tinto, the particular variant being known as the " Dotsch " process . This consists in stacking the broken ore in heaps and adding a mixture of sodium sulphate and ferric chloride in the proportions necessary for the entire conversion of the iron into ferric sulphate . The heaps are moistened with ferric chloride solution, and the reaction is nfaintained by the liquid percolating through the heap . The liquid is run off at the See also:

• BASE

base of the heaps into the precipitating tanks, where the copper is thrown down by means of metallic iron . The ferrous chloride formed at the same time is converted into ferric chloride which can be used to moisten the heaps . This conversion is effected by allowing the ferrous chloride liquors slowly to descend a See also:

• TOWER (Lat. turris; Fr. tour, clocker; Ital. torre; Ger. Thurm)

tower, filled with pieces of wood, coke or See also:

• QUARTZ

quartz, where it meets an ascending current of See also:

• CHLORINE (symbol Cl, atomic weight 35`46 (0=16)

chlorine . The sulphate, oxide or chlorides, which are obtained from the sulphuretted ores, are lixiviated and the metal precipitated in the same manner as we have previously described . The metal so obtained is known as " See also:

• CEMENT (from Lat. caementum, rough pieces of stone, a shortened form of caedimentum, from caedere, to cut)

cement " copper . If it contains more than 55% of copper it is directly refined, while if it contains a See also:

• LOWER

lower percentage it is smelted with matte or calcined copper pyrites . The chief impurities are basic salts of iron, free iron, See also:

• GRAPHITE

graphite, and sometimes silica, antimony and iron arsenates . Washing removes some of these impurities, but some copper always passes into the slimes . If much carbonaceous matter be present (and this is generally so when iron sponge is used as the precipitant) the crude product is heated to redness in the air; this burns out the carbon, and, at the same time, oxidizes a little of the copper, which must be subsequently reduced .

A similar operation is conducted when arsenic is present; basic-lined reverberatory furnaces have been used for the same purpose . Electrolytic Refining.—The principles have long been known on which is based the electrolytic separation of copper from the certain elements which generally accompany it, whether these, like silver and gold, are valuable, or, like arsenic, antimony, bismuth, selenium and tellurium, are merely impurities . But it was not until the See also:

• DYNAMO (a shortened form of " dynamo-electric machine," from Gr. Sbvaµis, power)

dynamo was improved as a See also:

• MACHINE
• MACHINE (through Fr. from Lat. form machina of Gr. µnxavil)

machine for generating large quantities of See also:

• ELECTRICITY

electricity at a very low cost that the electrolysis of copper could be practised on a commercial See also:

• SCALE
• SCALE (1) A

scale . To-day, by See also:

• REASON (Lat. ratio, through French raison)

reason of other uses to which electricity is applied, electrically deposited copper of high conductivity is in ever-increasing demand, and commands a higher See also:

• PRICE
• PRICE, BARTHOLOMEW (1818–1898)
• PRICE, BONAMY (1807-1888)
• PRICE, RICHARD (1723-1791)

price than copper refined by fusion . This increase in value permits of copper with 4 not over L2 or $ro See also:

• WORTH
• WORTH, CHARLES FREDERICK (1825-1895)

worth of the precious metals being profitably subjected to electrolytic treatment . Thus many million ounces of silver and a great See also:

• DEAL

deal of gold are recovered which formerly were lost . The earliest serious See also:

• ATTEMPT (Lat. adtemptare, attentare, to try)

attempt to refine copper industrially was made by G . R . See also:

• ELKINGTON, GEORGE RICHARDS (1801-1865)

Elkington, whose first patent is dated 1865 . He cast crude copper, as obtained from the ore, into plates which were used as anodes, sheets of electro-deposited copper forming the cathodes . Six anodes were suspended, alternately with four cathodes, in a saturated solution of copper sulphate in a cylindrical See also:

• FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire-clay trough, all the anodes being connected in one parallel See also:

• GROUP

group, and all the cathodes in another . A See also:

• HUNDRED

hundred or more jars were coupled in series, the cathodes of one to the anodes of the next, and were so arranged that with the aid of side-pipes with leaden connexions and See also:

• INDIA
• INDIA, FRENCH

india-See also:

• RUBBER, INDIARUBBER

rubber See also:

• JOINTS

joints the electrolyte could, once daily, be made to circulate through them all from the See also:

• TOP (cf. Dan. top, Ger. Topf, also meaning pot)

top of one See also:

• JAR

jar to the bottom of the next .

The current from a See also:

• WILDE, OSCAR

Wilde's dynamo was passed, apparently with a current See also:

• DENSITY (Lat. densus, thick)

density of 5 or 6 amperes per sq. ft., until the anodes were too crippled for further use . The cathodes, when thick enough, were either cast and rolled or sent into the See also:

• MARKET (Lat. mercatus, trade or place of trade)

market direct . Silver and other insoluble impurities collected at the bottom of the trough up to the level of the lower side-See also:

• TUBE (Lat. tuba)

tube, and were then run off through a plug in the bottom into settling tanks, from which they were removed for metallurgical treatment . The electrolyte was used until the See also:

• ACCUMULATION (from Lat. accumulare, to heap up)

accumulation of iron in it was too great, but was mixed from time to time with a little water acidulated by sulphuric acid . This process is of historic interest, and in principle it is identical with that now used . The modifications introduced have been chiefly in details, in order to economize materials and labour, to ensure purity of product, and to increase the rate of deposition . The See also:

• CHEMISTRY
• CHEMISTRY (formerly "chymistry"; Gr. xvµela; for derivation see ALCHEMY)

chemistry of the process has been studied by See also:

• MARTIN (Martinus)
• MARTIN, BON LOUIS HENRI (1810-1883)
• MARTIN, CLAUD (1735-1800)
• MARTIN, FRANCOIS XAVIER (1762-1846)
• MARTIN, HOMER DODGE (1836-1897)
• MARTIN, JOHN (1789-1854)
• MARTIN, LUTHER (1748-1826)
• MARTIN, SIR THEODORE (1816-1909)
• MARTIN, SIR WILLIAM FANSHAWE (1801–1895)
• MARTIN, ST (c. 316-400)
• MARTIN, WILLIAM (1767-1810)

Martin Kiliani (See also:

• BERG (Ducatus Montensis)

Berg- and Hultenm¢nnische Zeitung, 1885, p . 249), who found that, using the (low) current-density of 1.8 See also:

• AMPERE, ANDRE MARIE (1775–1836)
• AMPERE, JEAN JACQUES (1800-1864)

ampere per sq. ft. of See also:

• CATHODE

cathode, and an electrolyte containing See also:

• R2(rt-s2)

r2 lb of copper sulphate and lb of sulphuric acid per See also:

• GALLON

gallon, all the gold, See also:

• PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum and silver present in the crude copper anode remain as metals, undissolved, in the anode slime or mud, and all the lead remains there as sulphate, formed by the action of the sulphuric acid (or SO4 ions) ; he found also that arsenic forms arsenious oxide, which dissolves until the solution is saturated, and then remains in the slime, from which on long See also:

• STANDING

standing it gradually dissolves, after conversion by secondary reactions into arsenic oxide; antimony forms a basic sulphate which in part dissolves; bismuth partly dissolves and partly remains, but the dissolved portion tends slowly to separate out as a basic salt which becomes added to the slime; cuprous oxide, sulphide and selenides remain in the slime, and very slowly pass into solution by See also:

• SIMPLE

simple chemical action; tin partly dissolves (but in part separates again as basic salt) and partly remains as basic sulphate and stannic oxide; zinc, iron, nickel and cobalt pass into solution—more readily indeed than does the copper . Of the metals which dissolve, none (except bismuth, which is rarely present in any quantity) deposits at the anode so long as the solution retains its proper proportion of copper and acid, and the current-density is not too great . Neutral solutions are to be avoided because in them silver dissolves from the anode and, being more electro-negative than copper, is deposited at the cathode, while antimony and arsenic are also deposited, imparting a dark colour to the copper . Electrolytic copper should contain at least 99.92 % of metallic copper, the See also:

• BALANCE (derived through the Fr. from the Late Lat. bilantia, an apparatus for weighing, from bi, two, and lanx, a dish or scale)

balance consisting mainly of oxygen with not more than o•o1 % in all of lead, arsenic, antimony, bismuth and silver . Such a degree of purity is, however, unattainable unless the conditions of electrolysis are rigidly adhered to .

It should be observed that the free acid is gradually neutralized, partly by chemical action on certain constituents of the slime, partly by local action between different metals of the anode, both of which effect solution independently of the current, and partly by the peroxidation (or aeration) of ferrous sulphate formed from the iron in the anode . At the same time there is a See also:

• GRADUAL (Med. Lat. gradualis, of or belonging to steps or degrees; gradus, step)

gradual substitution of other metals for copper in the solution, because although copper plus other (more electro-See also:

• POSITIVE (or PORTABLE) ORGAN

positive) metals are constantly dissolving at the anode, only copper is deposited at the cathode . Hence the See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition and acidity of the solution, on which so much depends, must be constantly watched . The dependence of the mechanical qualities of the copper upon the current-density employed is well known . A very weak current gives a See also:

• PALE (through Fr. pal, from Lat. palms, a stake, for paglus, from the stem pag- of pangere, to fix; " pole " is from the same original source)

pale and brittle deposit, but as the current-density is in-creased up to a certain point, the properties of the metal improve; beyond this point they deteriorate, the colour becoming darker and the deposit less coherent, until at last it is dark brown and spongy or pulverulent . The presence of even a small proportion of hydrochloric acid imparts a brown tint to the deposit . See also:

• BARON
• BARON (1835-1895)
• BARON, MICHEL (1653—1729)

Baron H. v . Hiibl (Miltheil. See also:

• DES

des k. k. mililar-geograph . Inst., 1886, vol. vi. p . 51) has found that with neutral solutions a 5 % solution of copper sulphate gave no See also:

• GOOD, JOHN MASON (1764-1827)

good result, while with a go ''A solution the best deposit was obtained with a current-density of 28 amperes per sq. ft.; with solutions containing 2 % of sulphuric acid, the 5 % solution gave good deposits with current-densities of 4 to 7.5 amperes, and the 20% solution with 11.5 to 37 amperes, per sq. ft . The maximum current-densities for a pure acid solution at See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

rest were : for 15 % pure copper sulphate solutions 14 to 21 amperes, and for 20 % solutions 18.5 to 28 amperes, per sq. ft.; but when the solutions were kept in See also:

• GENTLE (through the Fr. gentil, from Lat. gentilis, belonging to the same gens, or family)

gentle motion these See also:

• MAXIMA

maxima could be increased to 21-28 and 28-37 amperes per sq. ft. respectively . The See also:

• NECESSITY (Lat. necessitas)

necessity for adjusting the current-density to the composition and treatment of the electrolyte is thus apparent .

The advantage of keeping the solution in motion is due partly to the renewal of solution thus effected in the neighbourhood of the electrodes, and partly to the neutralization of the tendency of liquids undergoing electrolysis to separate into layers, due to the different specific gravities of the solutions flowing from the opposing electrodes . Such an irregular See also:

• DISTRIBUTION (Lat. distribuere, to deal out)

distribution of the See also:

• BATH
• BATH, THOMAS THYNNE
• BATH, WILLIAM

bath, with strong copper sulphate solution from the anode at the bottom and acid solution from the cathode at the top, not only alters the conductivity in differeit strata and so causes irregular current-distribution, but may lead to the current-density in the upper layers being too great for the proportion of copper there present . Irregular and defective deposits are therefore obtained . See also:

• PROVISION (Lat. provisio)

Provision for circulation of solution is made in the systems of copper-refining now in use . See also:

• HENRY
• HENRY (1129-1195)
• HENRY (c. 1108-1139)
• HENRY (c. 1174–1216)
• HENRY (Fr. Henri; Span. Enrique; Ger. Heinrich; Mid. H. Ger. Heinrich and Heimrich; O.H.G. Haimi- or Heimirih, i.e. " prince, or chief of the house," from O.H.G. heim, the Eng. home, and rih, Goth. reiks; compare Lat. rex " king "—" rich," therefore " mig
• HENRY, EDWARD LAMSON (1841– )
• HENRY, JAMES (1798-1876)
• HENRY, JOSEPH (1797-1878)
• HENRY, MATTHEW (1662-1714)
• HENRY, PATRICK (1736–1799)
• HENRY, PRINCE OF BATTENBERG (1858-1896)
• HENRY, ROBERT (1718-1790)
• HENRY, VICTOR (1850– )
• HENRY, WILLIAM (1795-1836)

Henry Wilde, in 1875, in depositing copper on iron See also:

• PRINTING (from Lat. imprimere, O. Fr. empreindre)

printing-rollers, recognized this principle and rotated the rollers during electrolysis, thereby renewing the surfaces of metal and liquid in mutual contact, and imparting sufficient motion to the solution to prevent stratification; as an alternative he imparted motion to the electrolyte by means of propeller See also:

• BLADES, WILLIAM (1824-1890)

blades . Other workers have followed more or less on the same lines; reference may be made to the See also:

• PATENTS

patents of F . E. and A . S . Elmore, who sought to improve the character of the deposit by burnishing during electrolysis, of E . See also:

• DUMOULIN, CHARLES [MOLINAEUS] (1500-1566)

Dumoulin, and Sherard See also:

• COWPER, WILLIAM (1731-1800)
• COWPER, WILLIAM COWPER, 1ST EARL (c. 1665-1723)

Cowper-Coles (See also:

• ENGINEERING

Engineering See also:

• REVIEW (Fr. revue, from revoir, to see again, Lat. re and videre)

Review, 10o5, vol. xiii. p . 392), who prefers to rotate the cathode at a See also:

• SPEED, JOHN (1552–1629)

speed that maintains a peripheral velocity of at least woo ft. per minute . Certain other inventors have applied the same principle in a different way .

H . Thofehrn in America and J . C . See also:

• GRAHAM, SIR GERALD (1831–1899)
• GRAHAM, SIR JAMES ROBERT GEORGE
• GRAHAM, SYLVESTER (1794-1851)
• GRAHAM, THOMAS (1805-1869)

Graham iii England have patented processes by which jets of the electrolyte are caused to impinge with considerable force upon the surface of the cathode, so that the renewal of the liquid at this point takes See also:

• PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place very rapidly, and current-densities per sq. ft. of 5o to too amperes are recommended by the former, and of 300 amperes by the latter . Graham has described experiments in this direction, using a See also:

• JET (Fr. jais, Ger. Gagat)

jet of electrolyte forced (beneath the surface of the bath) through a hole in the anode upon the surface of the cathode . Whilst the jet was playing, a good deposit was formed with so high a current-density as 28o amperes per sq. ft., but if the jet was checked, the deposit (now in a still liquid) was instantaneously ruined . When two or more jets were used side by side the deposit was good opposite the centre of each, but See also:

• BAD, BCD

bad at the point where two currents met, because the rate of flow was reduced . By introducing perforated See also:

• SHIELDS, JAMES (181b-1879)

shields of ebonite between the electrodes, so that the full current-density was only attained at the centres of the jets, these See also:

• ILL

ill effects could be prevented . One of the chief troubles met with was the formation of arborescent growths around the edges of the cathode, due to the greater current-density in this region; this, however, was also obviated by the use of screens . By means of a very brisk rotation of cathode, combined with a rapid current of electrolyte, J . W . See also:

• SWAN (A. S. swan and swan, Icel. svanr, Du. zwaart, Ger. Schwan)
• SWAN, J
• SWAN, JOHN MACALLAN (1847-1910)
• SWAN, SIR JOSEPH WILSON (1828– )

Swan has succeeded in depositing excellent copper at current-densities exceeding woo amperes per sq. ft .

The methods by which such results are to be obtained cannot, however, as yet be practised economically on a working scale; one great difficulty in applying them to the refining of metals is that the jets of liquid would be liable to carry with them articles of anode mud, and Swan has shown that the presence of solid particles in the electrolyte is one of the most fruitful causes of the well-known nodular growths on electrodeposited copper . Experiments on a working scale with one of the jet processes in America have, it is reported, been given up after a full trial . In copper-refining practice, the current-density commonly ranges from 7.5 to 12 or 15, and occasionally to 18, amperes per sq. ft . The See also:

• ELECTRICAL
• ELECTRICAL (or ELECTROSTATIC) MACHINE

electrical pressure required to force a current of this intensity through the solution, and to overcome a certain opposing electromotive force arising from the more electro-negative impurities of the anode, depends upon the composition of the bath and of the anodes, the distance between the electrodes, and the temperature, but under the usual working conditions averages 0.3 volt for every pair of electrodes in series . In nearly all the processes now used, the solution contains about I q to 2 lb of copper sulphate and from 5 to 10 oz. of sulphuric acid per gallon of water, and the space between the electrodes is from 11 to 2 in., whilst the See also:

• TOTAL

total area of cathode surface in each tank may be 200 sq. ft., more or less . The anodes are usually cast copper plates about (say) 3 ft. by 2 ft. by or t in . The cathodes are frequently of electro-deposited copper, deposited to a thickness of aboutz in. on black-leaded copper plates, from which they are stripped before use . The tanks are commonly constructed of wood lined with lead, or tarred inside, and are placed in See also:

• TERRACE (Fr. terrace, terrasse, from It. terraccia, terrazzo, Lat. terra, earth)

terrace See also:

• FASHION (adapted from Fr. facon, agon, Lat. factio, making, facere, to do or make)

fashion each a little higher than the next in series, to facilitate the flow of solution through them all from a cistern at one end to a well at the other . Gangways are left between adjoining rows of tanks, and an overhead travelling-crane facilitates the removal of the electrodes . The arrangement of the tanks depends largely upon the voltage available from the electric generator selected; commonly they are divided into See also:

• GROUPS
• GROUPS, THEORY

groups, all the See also:

• BATHS

baths in each group being in series . In the huge See also:

• ANACONDA

Anaconda plant, for example, in which 15o tons of refined copper can be produced daily by the Thofehrn multiple system (not the jet system alluded to above), there are 600 tanks about 84 ft. by 4; ft. by 3; ft. deep, arranged in three groups of 200 tanks in series . The connexions are made by copper rods, each of which, in length, is twice the width of the tank, with a See also:

• BAYONET

bayonet-See also:

• BEND

bend in the See also:

• MIDDLE

middle, and serves to support the cathodes in the one and the anodes in the next tank .

Self-registering voltmeters indicate at any moment the potential difference in every tank, and therefore give notice of short circuits occur-See also:

• RING (O.E. hring; a word common to Teutonic languages; and probably cognate with the Lat. circus, Gr. KtpKOS or KpLKOS, Skt'. chakra, wheel, circle, cf. also " harangue "); in art, a band of circular shape of varying sizes, made of any material and used f

ring at any part of the See also:

• INSTALLATION

installation . The chief See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences between the commercial systems of refining See also:

• LIE, JONAS LAURITZ EDEMIL (1833—1908)
• LIE, MARIUS SOPHUS (1842–1899)

lie in the arrangement of the baths, in the disposition and manner of supporting the electrodes in each, in the method of circulating the solution, and in the current-density employed . The various systems are often classed in two groups, known respectively as the Multiple and Series systems, depending upon the arrangement of the electrodes in each tank . Under the multiple system anodes and cathodes are placed alternately, all the anodes in one tank being connected to one See also:

• ROD (O.E. rodd, probably related to Norw. rudda, stick, rodda, stake)
• ROD, EDOUARD (1857-1910)

rod, and all the cathodes to another, and the potential difference between the terminals of each tank is that between a single pair of plates . Under the series system only the first anode and the last cathode are connected to the conductors; between these are suspended, isolated from one another, a number of intermediate bi-polar electrode plates of raw copper, each of these plates acting on one side as a cathode, receiving a deposit of copper, and on the other as an anode, passing into solution; the voltage between the terminals of the tank will be as many times as great as that between a single pair of plates as there are spaces between electrodes in the tank . In time the original impure copper of the plates becomes replaced by refined copper, but if the plates are initially very impure and dissolve irregularly, it may happen that much residual scrap may have to be remelted, or that some of the metal may be twice refined, thus involving awaste of See also:

• ENERGY (from the Gr. ivipyela; iv, in, ipyov, work)

energy . Moreover, the high potential difference between the terminals of the series tank introduces a greater danger of short-circuiting through scraps of metal at the bottom of the bath ; for this reason, also, lead-lined vats are inadmissible, and tarred slate tanks are often used instead . A valuable comparison of the multiple and series systems has been published by E . Keller (see The Mineral Industry, New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York, 1899, vol . Vii. p . 229) . G .

Kroupa has calculated that the cost of refining is 8s. per ton of copper higher under the series than it is under the multiple system ; but against this, it must be remembered that the new works of the See also:

• BALTIMORE
• BALTIMORE, GEORGE CALVERT, 1ST BARON (C. 1580—1632)

Baltimore Copper Smelting and See also:

• ROLLING

Rolling Company, which are as large as those of the Anaconda Copper See also:

• MINING

Mining Company, are using the See also:

• HAYDEN, FERDINAND VANDEVEER (1829–1887)

Hayden process, which is the chief representative of the several series systems . In this system rolled copper anodes are used; these, being purer than many cast anodes, having See also:

• FLAT (a modification of O. Eng. flet, an obsolete word of Teutonic origin, meaning the ground beneath the feet)

flat surfaces, and being held in place by guides, dissolve with great regularity and require a space of only t in. between the electrodes, so that the potential difference between each pair of plates may be reduced to 0.15–0.2 volt . J . A . W . Borchers, in Germany, and A . E . See also:

• SCHNEIDER, JOHANN GOTTLOB (1750-1822)
• SCHNEIDER, LOUIS (1805-1878)

Schneider and O . Szontagh, in America, have introduced a method of circulating the solution in each vat by forcing air into a vertical See also:

• PIPE

pipe communicating between the bottom and top of a tank, with the result that the bubbling of the air upward aspirates solution through the vertical pipe from below, at the same time aerating it, and causing it to overflow into the top of the tank . Obviously this slow circulation has but little effect on the rate at which the copper may be de-posited . The electrolyte, when too impure for further use, is commonly recrystallized, or electrolysed with insoluble anodes to recover the copper . The yield of copper per ampere (in round See also:

• NUMBERS, BOOK OF
• NUMBERS, PARTITION OF

numbers, z oz. of copper per ampere per diem) by See also:

• FARADAY, MICHAEL (1791-1867)

Faraday's See also:

• LAW
• LAW (0. Eng. lagu, M. Eng. lawe; from an old Teutonic root lag, " lie," what lies fixed or evenly; cf. Lat. lex, Fr. loi)
• LAW, JOHN (1671—1729)
• LAW, WILLIAM (1686-1761)

law is never attained in practice ; and although 98 % may with care be obtained, from 94 to 96% represents the more usual current-efficiency .

With 100 % current-efficiency and a potential difference of 0.3 volt between the electrodes, lb of copper should require about 0.154 electrical See also:

• HORSE (a word common to Teutonic languages in such forms as hors, hros, ros; cf. the Ger. ross)

horse-power hours as the amount of energy to be expended in the tank for its See also:

• PRODUCTION (Lat. productionem, from producere, to pro-duce)

production . In practice the See also:

• EXPENDITURE

expenditure is somewhat greater than this; in large works the See also:

• GROSS

gross horse-power required for the refining itself and for power and See also:

• LIGHTING

lighting in the factory may not exceed 0.19 to 0.2 (or in smaller works 0.25) horse-power hours per pound of copper refined . Many attempts have been made to use crude sulphide of copper or matte as an anode, and recover the copper at the cathode, the sulphur and other insoluble constitutents being left at the anode . The best known of these is the Marchese process, which was tested on a working scale at See also:

• GENOA (anc. Genua, Ital. Genova, Fr. GPnes)

Genoa and See also:

• STOLBERG
• STOLBERG, FRIEDRICH LEOPOLD, GRAF ZU (1750-1819)

Stolberg in Rhenish See also:

• PRUSSIA
• PRUSSIA (Ger. Preussen; Lat. Borussia)

Prussia . As the operation proceeded, it was found that the voltage had to be raised until it became prohibitive, while the anodes rapidly became honeycombed through and, crumbling away, filled up the space at "the bottom of the vat . The process was abandoned, but in a modified form appears to be now in use in Nijni-See also:

• NOVGOROD
• NOVGOROD (formerly known as V elikiy-Novgorod, Great Novgorod)

Novgorod in See also:

• RUSSIA
• RUSSIA (Rossiya)

Russia . See also:

• SIEMENS, ERNST WERNER VON (1816-1892)
• SIEMENS, SIR WILLIAM [KARL WILHELM] (1823-1883)

Siemens and Halske introduced a combined process in which the ore, after being part-roasted, is leached by solutions from a previous electrolytic operation, and the resulting copper solution electrolysed . In this process the anode solution had to be kept separate from the cathode solution, and the membrane which had in consequence to be used, was liable to become torn, and so to cause trouble by permitting the two solutions to mix . Modifications of the process have therefore been tried . Modern methods in copper smelting and refining have effected enormous See also:

• ECONOMY

economy in time, space, and labour, and have consequently increased the world's output . With pyritic smelting a sulphuretted copper ore, fed into a cupola in the See also:

• MORNING

morning, can be passed directly to the converter, blown up to metal, and shipped as 99% bars by evening—an operation which formerly, with heap roasting of the ore and repeated roasting of the mattes in stalls, would have occupied not less than four months . A large furnace and a Bessemer converter, the pair capable of making a million pounds of copper a See also:

• MONTH
• MONTH (a common Teutonic word, cf. Ger. Mond, Du. maand, Dan. maaned, &c., and cognate with Lat. mensis, Gr. µi7v, &c., in other branches of the Indo-Germanic family; all ultimately from the root seen in the word for the moon in nearly all those languages

month from a low-grade sulphuretted ore, will not occupy a space of more than 25 ft. by zoo ft.; and whereas, in making metallic copper out of a low-grade sulphuretted ore, one day's labour used to be expended on every ton of ore treated, to-day one day's labour will carry at least four tons of ore through the different mechanical and metallurgical processes necessary to reduce them to metal .

About 7o% of the world's See also:

• ANNUAL

annual copper output is refined electrolytically, and from the 461,583 tons refined in the United States in 1907, there were recovered 13,995,436 oz. of silver and 272,150 oz. of gold . The recovery of these valuable metals has contributed in no small degree to the expansion of electrolytic refining . Production.—The See also:

• SOURCES

sources of copper, its applications and its metallurgy, have undergone great changes . Chile was the largest producer in 1869 with 54,867 tons; but in 1899 her production had fallen off to 25,000 tons . Great See also:

• BRITAIN (Gr. Hperavuml vi7vot, Bperravia; Lat. Britannia, rarely Britannia)

Britain, though she had made See also:

• HALF

half the world's copper in 183o, held second place in r86o, making from native ores 15,968 tons; in 1900 her production was 777 tons, and in 1907, 711 tons . The United States made only 572 tons in 185o, and 12,600 tons in 1870; but she to-day makes more than 6o% of the world's total . In 1879, Spain was the largest producer, but now ranks third . The estimated total production for each See also:

• DECADE (from Gr. Oka, ten)

decade of the 19th See also:

• CENTURY (from Lat. centuria, a division of a hundred men)

century in metric tons is here shown: 18oI-1810 91,000 1811-1820 96,000 1821-1830 135,000 1831-1840 ^ 218,400 1841-1850 • 291,000 1851-1860 • 506,999 1861-1870 900,000 1871-1880 I,189,000 1881-1890 . 2,373,398 1891-1900 3,708,901 The following table gives the output of various countries and the world's production for the years 1895, 1900, 1905, 1907:- Country . 1895 . 1900 . 1905 .

1907 . United States . . 175,294 274,933 397,003 398,736 Spain and See also:

• PORTUGAL

Portugal 55,755 53,718 45,527 50,470 Japan . . . 18,725 28,285 36,485 49,718 Chile 22,428 26,016 29,632 27,112 Germany . . 16,799 20,635 22,492 20,818 See also:

• AUSTRALASIA

Australasia Io,16o 23,368 34,483 41,910 See also:

• MEXICO
• MEXICO (Span. Mejico, or Mexico,)
• MEXICO, FEDERAL DISTRICT OF
• MEXICO, GULF OF

Mexico 12,806 22,473 70,010 61,127 Russia 5,364 8,128 8,839 15,240 World's production . 339,994 496,819 699,514 723,807 As the stock on hand rarely exceeds three months' demand, and is often little more than a month's supply, it is evident that consumption has kept See also:

• CLOSE
• CLOSE (from Lat. clausum, shut)
• CLOSE, MAXWELL HENRY (1822-1903)

close See also:

• PACE (through O. Fr. pas, from Lat. passus, step, properly the stretch of the leg in walking, from pandere, to stretch)
• PACE, RICHARD (c. 1482-1536)

pace with production . The large demand for copper to be used in sheathing See also:

• SHIPS

ships ceased on the introduction of iron in See also:

• SHIPBUILDING

shipbuilding because of the difficulty of coating iron with an impervious layer of copper; but the consumption in the manufacture of electric apparatus and for electric conductors has far more than compensated . Alloys of Copper,-Copper unites with almost all other metals, and a large number of its alloys are of importance in the arts . The principal alloys in which it forms a leading ingredient are See also:

• BRASS
• BRASS (O. Eng. braes)

brass, bronze, and German or nickel silver; under these several heads their respective applications and qualities will be found . Compounds of Copper.-Copper probably forms six oxides, viz . Cu40, Cu30, Cu2O, CuO, Cu20, and CuOs .

The most important are cuprous oxide, Cu2O, and cupric oxide, CuO, both of Oxides which give rise to well-defined series of salts . The other and by oxides do not possess this See also:

• PROPERTY

property, as is also the case droxides. of the hydrated oxides Cu3022H2O and Cu4025H2O, de-scribed by M . Siewert . Cuprous oxide, Cu2O, occurs in nature as the mineral cuprite (q.v.) . It may be prepared artificially by heating copper See also:

• WIRE (A.S. wir, a wire; cf. Swed. vire, to twist, M.H.G. wiere, a gold ornament, Lat. viriae, armlets, ultimately from the root wi, to twist, bind)

wire to a white heat, and afterwards at a red heat, by the atmospheric oxidation of copper reduced in hydrogen, or by the slow oxidation of the metal udder water, It is obtained as a fine red crystalline precipitate by reducing an alkaline copper solution with See also:

• SUGAR

sugar . When finely divided it is of a fine red colour . It fuses at red heat, and See also:

• COLOURS, MILITARY

colours See also:

• GLASS
• GLASS (O.E. glees, cf. Ger. Glas, perhaps derived from an old Teutonic root gla-, a variant of glo-, having the general sense of shining, cf. " glare," " glow ")
• GLASS, STAINED

glass a See also:

• RUBY (Lat. rubeus, red)

ruby-red . The property was known to the ancients and during the middle ages; it was then lost for several centuries, to be rediscovered in about 1827 . Cuprous oxide is reduced by hydrogen, carbon monoxide, charcoal, or iron, to the metal ; it dissolves in hydrochloric acid forming cuprous chloride, and in other mineral acids to form cupric salts, with the separation of copper . It dissolves in See also:

• AMMONIA (NH3)

ammonia, forming a colourless solution which rapidly oxidizes and turns blue . A hydrated cuprous oxide, (4Cu2O, H20), is obtained as a See also:

• BRIGHT, JOHN (1811-188g)
• BRIGHT, SIR CHARLES TILSTON

bright yellow See also:

• POWDER (through O. Fr. puldre, modern poudre, from Lat. pulvis, pulveris, dust)

powder, when cuprous chloride is treated with potash or soda . It rapidly absorbs oxygen, assuming a blue colour .

Cuprous oxide corresponds to the series of cuprous salts, which are mostly white in colour, insoluble in water, and readily oxidized to cupric salts . Cupric oxide, CuO, occurs in nature as the mineral melaconite (q.v.), and can be obtained as a hygroscopic black powder by the gentle ignition of copper nitrate, carbonate or hydroxide; also by heating the hydroxide . It oxidizes carbon compounds to carbon dioxide and water, and therefore finds extensive application in See also:

• ANALYTICAL

analytical organic chemistry . It is also employed to colour glass, to which it imparts a See also:

• LIGHT

light green colour . Cupric hydroxide, Cu(OH)2, is obtained as a greenish-blue flocculent precipitate bymixing cold solutions of potash and a cupric salt . This precipitate always contains more or less potash, which cannot be entirely removed by washing . A purer product is obtained by adding ammonium chloride, filtering, and washing with hot water . Several hydrated oxides, e.g . Cu(OH),.3CuO,Cu(OH)2.6H2O,6CuO•See also:

• H2O (combined)

H2O, have been described . Both the oxide and hydroxide dissolve in ammonia to form a beautiful See also:

• AZURE (derived, through the Romance languages, from the Arabic al-lazward, for the precious stone lapis lazuli, the initial 1 having dropped)

azure-blue solution (Schweizer's reagent), which dissolves See also:

• CELLULOSE

cellulose, or perhaps, holds it in suspension as water does See also:

• STARCH

starch; accordingly, the solution rapidly perforates See also:

• PAPER
• PAPER (Fr. papier, from Lat. papyrus)

paper or See also:

• CALICO

calico . The salts derived from cupric oxide are generally white when anhydrous, but blue or green when hydrated . Copper quadrantoxide, Cu40, is an See also:

• OLIVE (Olea europaea)

olive-green powder formed by mixing well-cooled solutions of copper sulphate and alkaline stannous chloride .

The trientoxide, Cu3O, is obtained when cupric oxide is heated to 1500°-2000° C . It forms yellowish-red crystals, which scratch glass, and are unaffected by all acids except hydrofluoric; it also dissolves in molten potash . Copper dioxide, CuO2H20, is obtained as a yellowish-brown powder, by treating cupric See also:

• HYDRATE

hydrate with hydrogen peroxide . When moist, it decomposes at about 6° C., but the dry substance must be heated to about 18o°, before decomposition sets in (see L . See also:

• MOSER, JOHANN JAKOB (1701-1785)
• MOSER, JUSTUS (172o-1794)

Moser, Abst . J.C.S., 1907, H. p . 549) . Cuprous hydride, (CuH)a, was first obtained by See also:

• WURTZ, CHARLES ADOLPHE (1817–1884)

Wurtz in 1844, who treated a solution of copper sulphate with hypophosphorous acid, at a temperature not exceeding 7o° C . According to E . J . See also:

• BARTLETT, JOHN (1820-1905)
• BARTLETT, JOHN RUSSELL (18o5-1886)
• BARTLETT, PAUL WAYLAND (18654 )

Bartlett and W . H .

See also:

• MERRILL

Merrill, it decomposes when heated, and gives cupric hydride, CuH2, as a reddish-brown spongy See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass, which turns to a See also:

• CHOCOLATE

chocolate colour on exposure . It is a strong reducing See also:

• AGENT (from Lat. agere, to act)

agent . Cuprous fluoride, CuF, is a ruby-red crystalline mass, formed by heating cuprous chloride in an atmosphere of hydrofluoric acid at 1100°-12oo° C . It is soluble in boiling hydrochloric acid, but it is not reprecipitated by water, as is the case with cuprous chloride . Cupric fluoride, CuF2, is obtained by dissolving cupric oxide in hydrofluoric acid . The hydrated form, (CuF2, 2H2O, 5HF),is obtained as blue crystals, sparingly soluble in cold water; when heated to See also:

• LOO (formerly called " Lanterloo," Fr. lanturlu, the refrain of a popular 17th-century song)

loo° C. it gives the compound CuF(OH), which, when heated with ammonium fluoride in a current of carbon dioxide, gives anhydrous copper fluoride as a white powder . Cuprous chloride, CuCI or Cu2C12, was obtained by Robert See also:

• BOYLE
• BOYLE, JOHN J
• BOYLE, ROBERT (1627-1691)

Boyle by heating copper with mercuric chloride . It is also obtained by burning the metal in chlorine, by heating copper and cupric oxide with hydrochloric acid, or copper and cupric chloride with hydrochloric acid . It dissolves in the excess of acid, and is precipitated as a white crystalline powder on the addition of water . It melts at below red heat to a brown mass, and its vapour density at both red and white heat corresponds to the See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula Cu2Cl2• It turns dirty See also:

• VIOLET

violet on exposure to air and light; in moist air it absorbs oxygen and forms an oxychloride . Its solution in hydrochloric acid readily absorbs carbcn monoxide and See also:

• ACETYLENE

acetylene; hence it finds application in gas See also:

• ANALYSIS (Gr. avci and Meta, to break up into parts)

analysis . Its solution in ammonia is at first colourless, but rapidly turns blue, owing to oxidation .

This solution absorbs acetylene with the precipitation of red cuprous acetylide, Cu2C2, a very explosive compound . Cupric chloride, CuC12, is obtained by burning copper in an excess of chlorine, or by heating the hydrated chloride, obtained by dissolving the metal or cupric oxide in an excess of hydrochloric acid . It is a brown deliquescent powder, which rapidly forms the green hydrated salt CuC12, 2I-P2O on exposure . The oxychloride Cu302C12.4H2O is obtained as a pale blue precipitate when potash is added to an excess of cupric chloride . The oxychloride Cu40,C12,4H2O occurs in nature as the mineral atacamite . It may be artificially prepared by heating salt with ammonium copper sulphate to loo° . Other naturally occurring oxychlorides are botallackite and tallingite . " See also:

• BRUNSWICK
• BRUNSWICK (Ger. Braunschweig)
• BRUNSWICK, KARL WILHELM FERDINAND, DUKE OF (1735-18o6)

Brunswick green," a light green pigment, is obtained from copper sulphate and See also:

• BLEACHING

bleaching powder . The bromides closely resemble the chlorides and fluorides . Cuprous iodide, Cu2I2, is obtained as a white powder, which suffers little alteration on exposure, by the direct See also:

• UNION
• UNION (known locally as Union Hill and officially as Town of Union)

union of its components or by mixing solutions of cuprous chloride in hydrochloric acid and See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium iodide; or, with liberation of See also:

• IODINE (symbol I, atomic weight '26.92)

iodine, by adding potassium iodide to a cupric salt . It absorbs ammonia, forming the compound Cu2I2, 4NH3 . Cupric iodide is only known in combination, as in CuI2, 4NH3, H2O, which is obtained by exposing Cu212,4NH3 to moist air .

Cuprous sulphide, Cu2S, occurs in nature as the mineral chalcocite or copper-glance (q.v.), and may be obtained as a black brittle mass by the direct combination of its constituents . (See above, Metallurgy.) Cupric sulphide, CuS, occurs in nature as the mineral covellite . It may be prepared by heating cuprous sulphide with sulphur, or triturating cuprous sulphide with cold strong nitric acid, or as a dark brown precipitate by treating a copper solution with sulphuretted hydrogen . Several polysulphides, e.g . Cu2S5, Cu2S5, Cu4S5, Cu2S3, have been described; they are all unstable, decomposing. into cupric sulphide and sulphur . Cuprous sulphite, CuS03•H2O, is obtained as a brownish-red crystalline powder by treating cuprous hydrate with sulphurous acid . A cuproso-cupric sulphite, Cu2SO3, CuS03,2H2O, is obtained by mixing solutions of cupric sulphate and acid sodium sulphite . Cupric sulphate or " Blue Vitriol," CuSO4, is one of the most important salts of copper . It occurs in cupriferous mine waters and as the minerals chalcanthite or cyanosite, CuSO4.5H2O, and boothite, CuSO4.7H2O . Cupric sulphate is obtained commercially by the oxidation of sulphuretted copper ores (see above, Metallurgy; wet methods), or by dissolving cupric oxide in sulphuric acid . It was obtained in 1644 by See also:

• VAN

Van See also:

• HELMONT, JEAN BAPTISTE VAN (1577—1644)

Helmont, who heated copper with sulphur and moistened the See also:

• RESIDUE (through the French, from the Lat. residuum, a remainder, from residere, to remain)

residue, and in 1648 by See also:

• GLAUBER, JOHANN RUDOLF (1604-1668)

Glauber, who dissolved copper in strong sulphuric acid . (For the mechanism of this reaction see C .

H . Sluiter, Chem . Weekblad, 1906, 3, p . 63, and C . M. van See also:

• DEVENTER

Deventer, ibid., 1906, 3, p . 515.) It crystallizes with five molecules of water as large blue triclinic prisms . When heated to loo°, it loses four molecules of water and forms the bluish-white monohydrate, which, on further heating to 250°-260°, is converted into the white CuSO4 . The anhydrous salt is very hygroscopic, and hence finds application as a desiccating agent . It also absorbs gaseous hydrochloric acid . Copper sulphate is readily soluble in water, but in-soluble in See also:

• ALCOHOL

alcohol; it dissolves in hydrochloric acid with a consider-able fall in temperature, cupric chloride being formed . The copper is readily replaced by iron, a See also:

• KNIFE (0. E. cuff, a word appearing in different forms in many Teutonic languages, cf. Du. knijf, Ger. Kneif, a shoe-maker's knife, Swed. knif; the ultimate origin is unknown; Skeat finds the origin in the root of " nip," formerly " knip "; Fr. canif is a

knife-blade placed in an aqueous solution being covered immediately with a bright red deposit of copper . At one time this was regarded as a transmutation of iron into copper .

Several basic salts are known, some of which occur as minerals; of these, we may mention See also:

• BROCHANTITE

brochantite (.v.), CuSO4, 3Cu(OH2), langite, CuSO4, 3Cu(OH)2, H20, lyellite (or devilline), warringtonite; woodwardite and enysite are hydrated copper-aluminium sulphates, See also:

• CONNELLITE

connellite is a basic copper chlorosulphate, and spangolite is a basic copper aluminium chlorosulphate . Copper sulphate finds application in calico printing and in the preparation of the pigment See also:

• SCHEELE, KARL WILHELM (1742-1786)

Scheele's green . A copper nitride, Cu3N, is obtained by heating precipitated cuprous oxide in ammonia gas (A . Guntz and H . Bassett, See also:

• BULL
• BULL, GEORGE (1634–1710)
• BULL, JOHN (c. 1562–1628)
• BULL, OLE BORNEMANN (18ro-188o)

Bull . See also:

• SOC

Soc . Chim., 1906, 35, p . 201) . A maroon-coloured powder, of composition CuNO2, is formed when pure dry nitrogen dioxide is passed over finely-divided copper at 25°-30° . It decomposes when heated to 90°; with water it gives nitric oxide and cupric nitrate and nitrite . Cupric nitrate, Cu (NOs)2, is obtained by dissolving the metal or oxide in nitric acid . It forms dark blue prismatic crystals containing 3, 4, or 6 molecules of water according to the temperature of crystallization .

The trihydrate melts at 114.5° and boils at 17o°, giving off nitric acid, and leaving the basic salt Cu(NO3)2.3Cu(OH)2 . The mineral gerhardtite is the basic nitrate Cu2(OH)3NOs . Copper combines directly with See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus to form several compounds . The phosphide obtained by heating cupric phosphate, Cu2H2P2Os, in hydrogen, when mixed with potassium and cuprous sulphides or levigated coke, constitutes " See also:

• ABEL (better ABELL), THOMAS (d. 1540)
• ABEL (Hebrew for breath)
• ABEL, KARL FRIEDRICH (1725-1787)
• ABEL, NIELS HENRIK (1802-1829)
• ABEL, SIR FREDERICK AUGUSTUS, BART

Abel's fuse," which is used as a primer . A phosphide, Cu2P2, is formed by passing phosphoretted hydrogen over heated cuprous chloride . (For other phosphides see E . See also:

• HEYN, PIETER PIETERZOON [commonly abbreviated to PIET] (1578-1629)

Heyn and 0 . See also:

• BAUER, BRUNO (1809-1882)

Bauer, See also:

• REP, REPP, or REPS

Rep . Chem . Soc., 1906, 3, p . 39.) Cupric phosphate, Cus(PO4)2, may be obtained by precipitating a copper solution with sodium phosphate . Basic copper See also:

• PHOSPHATES

phosphates are of frequent occurrence in the mineral See also:

• KINGDOM

kingdom .

Of these we may notice libethenite, Cu2(OH)PO4; chalcosiderite, a basic copper iron phosphate; See also:

• TORBERNITE (or cupro-uranite)

torbernite, a copper uranyl phosphate; andrewsite, a hydrated copper iron phosphate; and henwoodite, a hydrated copper aluminium phosphate . Copper combines directly with arsenic td' form several arsenides, some of which occur in the mineral kingdom . Of these we may mention whitneyite, Cu9 As, algodonite, Cu9AS, and domeykite, Cu 3As . Copper arsenate is similar to cupric phosphate, and the resemblance is to be observed in the naturally occurring copper arsenates, which are generally isomorphous with the corresponding phosphates . See also:

• OLIVENITE

Olivenite corresponds to libethenite; clinoclase, euchroite, cornwallite and tyrolite are basic arsenates; zeunerite corresponds to torbernite; chalcophyllite (tamarite or " copper-See also:

• MICA

mica ") is a basic copper aluminium sulphato-arsenate, and bayldonite is a similar compound containing lead instead of aluminium . Copper arsenite forms the basis of a number of once valuable, but very poisonous, See also:

• PIGMENTS (Lat. pigmentum, from pingere, to paint)

pigments . Scheele's green is a basic copper arsenite; See also:

• SCHWEINFURT

Schweinfurt green, an aceto-arsenite; and Casselmann's green a compound of cupric sulphate with potassium or sodium acetate . Normal cupric carbonate, CuCO3, has not been definitely obtained, basic hydrated forms being formed when an alkaline carbonate is added to a cupric salt . Copper carbonates are of wide occurrence in the mineral kingdom, and constitute the valuable ores malachite and azurite . Copper See also:

• RUST (O.E. rust, a word which appears in -many Teutonic languages, cf. Du. roest, Ger. rost); in origin it is allied with " ruddy " and " red," the reddish-brown powdery substance which forms on the surface of iron or steel exposed to atmospheric corrosio

rust has the same composition as malachite; it results from the action of carbon dioxide and water on the metal . Copper carbonate is also the basis of the valuable blue to green pigments verditer, See also:

• BREMEN

Bremen blue and Bremen green . Mountain or mineral green is a naturally occurring carbonate .

By the direct union of copper and See also:

• SILICON [symbol Si, atomic weight 28.3 (0= 16)]

silicon, cuprosilicon, consisting mainly of Cu4Si, is obtained (See also:

• LEBEAU, JOSEPH (1794-1865)

Lebeau, C.R., 1906; Vigouroux, ibid.) . Copper silicates occur in the mineral kingdom, many minerals owing their colour to the presence of a cupriferous See also:

• ELEMENT (Lat. elementum)

element . See also:

• DIOPTASE

Dioptase (q.v.) and chrysocolla (q.v.) are the most important forms . Detection.—Compounds of copper impart a bright green coloration to the flame of a See also:

• BUNSEN, CHRISTIAN CHARLES JOSIAS, BARON VON (1791-186o,)
• BUNSEN, ROBERT WILHELM VON (1811-1899)

Bunsen burner . Ammonia gives a characteristic blue coloration when added to a solution of a copper salt; potassium ferrocyanide gives a brown precipitate, and, if the solution be very dilute, a brown colour is produced . This latter reaction will detect one partof copper in 500,000 of water . For the See also:

• BORAX (sodium pyroborate or sodium biborate)

borax beads and the qualitative separation of copper from other metals, see CHEMISTRY: Analytical . For the quantitative estimation, see See also:

• ASSAYING

ASSAYING: Copper . See also:

• MEDICINE

Medicine.—In medicine copper sulphate was employed as an emetic, but its employment for this purpose is now very rare, as it is exceedingly depressant, and if it fails to See also:

• ACT (Lat. actus, actum)

act, may seriously damage the gastric mucous membrane . It is, however, a useful superficial See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic and antiseptic . All copper compounds are poisonous, but not so harmful as the copper arsenical pigments .