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)