COPPER MINES. Copper occurs in nature both in the metallic state, when it is known as native copper, and mineralized or combined with oxygen, sulphur, and various other foreign substances, constituting what are called the ores of copper. (See Copper.) This metal and its ores occur, like most other metals, both disseminated in beds of various kinds of rock, and in veins or lodes, which are deposits in fissures intersecting previously formed rocks. Copper and copper ores are found in rocks of very various geological ages. The crystalline schists of the eozoic age contain in many places both interstratified ore beds and lodes carrying the ores of this metal. This is true of the rocks of the great Appalachian system, which abound in deposits of copper ores in various localities, from Newfoundland through Quebec and Vermont into Virginia, the Carolinas, Tennessee, and Georgia. The copper ores of the Rocky mountains and those of Cuba and Chili are also in crystalline rocks; and the same is true of those of the Ural, of Norway, Sweden, Cornwall, and Devonshire. The great deposits of native copper found on the shores of Lake Superior, however, belong to a series of sandstones and conglomerates, interstratified with contemporaneous bedded trappean rocks, which rest upon the crystalline Huronian schists, and, being overlaid by the upper Cambrian rocks of the New York system, may be regarded as of the lower Cambrian age. Rich ores of copper occur in the palaeozoic series in the so-called Shawangunk grit of Ulster co., New York. In Connecticut, New Jersey, and Pennsylvania, deposits of copper ores are found in sandstones of the mesozoic age, and somewhat similar deposits occur in various parts of Europe. The well known mines of Mansfeld in Germany, in which a sulphuretted ore is finely disseminated through black bituminous schists, are examples. There are important mines in Siberia and the Ural mountains. The product of Russia is estimated at 4,660 tons a year. The Swedish copper mine of Fahlun, in Dalecarlia, is supposed to have been worked for nearly 1,000 years. It was long extremely productive, yielding in the beginning of the 17th century nearly 4,000 tons annually, but it has since greatly declined. There are mines in other parts of Sweden, where in 1855 there were 15 smelting works, producing 1,990 metric tons (2,205 lbs.) of pig copper; in 1863, 16 works, producing 2,222½ tons; in 1868, 12, producing 2,410 tons. The product for 1869 was 2,600 tons; for 1870, 2,193 tons. The exports of crude copper in 1867 amounted to 1,928 tons; in 1868, 2,320; in 1869, 2,076; and in 1870, 1,957. From Norway there were imported into Great Britain, in 1867, 6,007 tons of ore, worth £34,209, and 193 of unwrought or partly wrought copper; in 1868, 6,871 tons of ore, worth £66,995, and 216 of copper; in 1869, 6,589 of ore, worth £154,508, and 105 of copper; in 1870, 1,911 of ore, worth £9,110, and 100 of copper; in 1871, 4,299 tons of ore, worth 26,520, and 97 of copper. In the German empire copper is mined at Holzappel and elsewhere in Nassau; in the Eifel mountains, and at Eschweiler and Stolberg, near Aix-la-Chapelle; in Westphalia, and in the Hartz mountains, as well as at Mansfeld, in Prussian Saxony. In 1869, 217,415 metric tons of ore were obtained in the Zollverein, valued at about $1,300,000; in 1870, 207,381 tons, worth $1,250,000. The product of the smelting works in 1869 was 5,129 tons of copper, valued at over $2,000,000, and 4,730 tons of brass of about the same value; in 1870, 4,797 tons of copper, worth about $1,800,000, and 4,411 of brass, of about the same value. The value of sulphate of copper in 1869 was about $270,000, and in 1870 about $285,000. In 1869 the imports of copper and manufactures of the same amounted to 12,240 tons; the exports were 7,413 tons. In Prussia alone 156 copper mines were in operation in 1869, employing 6,691 miners, and producing 214,507 tons of ore, valued at about $1,275,000; 13 smelting works, employing 1,408 hands, and producing 4,448 tons of crude copper, worth about $1,750,000; 23 establishments, with 658 hands, producing 3,713 tons of copper manufactures, valued at $1,775,000; 77 establishments, with 1,381 hands, producing 4,722 tons of brass, worth about $2,025,000; and 2 manufactories of sulphate of copper, employing 47 hands, and producing 945 tons, valued at $110,000. The most important mines of the Austrian empire are in Hungary, though the metal is also found in Bohemia. The product of ore, metal, and sulphate, with the value of each, from 1863 to 1867, is shown in the following table:
The product of copper for 1869 was 2,698 metric tons.—In Italy copper is found in the mountains bordering the gulf of Genoa, and in Sardinia, and there are mines in the mountains of Modena, and in central and southern Tuscany. In 1865 there were 34 mines in Italy, employing 2,412 hands, and producing 16,075 metric tons of ore, valued at $318,725; and 21 smelting works, with 287 hands, producing 1,032½ tons of copper, worth $552,915. The average production during the period 1867-'70 was 25,500 tons of ore and 550 tons of pig copper.—In France there are copper mines at Chessy and St. Bel near Lyons, but the product is not large. Considerable quantities of ore and crude metal, however, are imported, and smelted in that country. The product of the mines and smelting works for different periods has been as follows:
The imports into France from 1857 to 1868 are shown by the following table:
Of the 71,697 tons of ore imported into France during that period, 22,119 were from Peru and 7,870 from Algeria. The value of manufactured, alloyed, and old copper imported in 1868 was $1,348,014. The exports in 1867 were 3,454 metric tons of ore and 2,647 of crude copper; in 1868, 2,976 tons of ore, 3,812 of crude copper, and $1,380,861 worth of manufactured copper.—Spain is one of the chief copper-producing countries, and its mines have long been famous. The most important are those of Huelva, near the Rio Tinto, in Andalusia. The quantity of ore raised has been as follows: in 1864, 294,079 metric tons; in 1866, 347,257; in 1868, 284,184. The amount worked at the government mine of Tinto in 1864 was 64,756 tons, producing 1,046½ tons of copper; in 1866, 67,608 tons, producing 1,135 tons of copper; in 1868, 56,453 tons, producing 1,124 tons of copper. The average fineness was 1¾ per cent. At the same rate the total copper product of the kingdom for 1864 would be 5,146 tons; in 1866, 6,077 tons; in 1868, 4,973 tons. From Portugal were exported to Great Britain, in 1868, 1,774 tons of ore, worth $125,830; in, 1869, 4,214 tons, worth $308,840; in 1870, 2,592 tons, worth $152,275; in 1871, 2,895 tons, worth $287,755.—In England, the mines of Cornwall and Devonshire were formerly the most productive known, but they have greatly declined. There are also some mines in Cumberland, Wales, and Ireland. In 1757 the mine called Huel Virgin, in Cornwall (now a part of the consolidated mines), produced in two weeks, at a cost of £100, copper ores which sold for £5,700; and in the next 23 days the product, obtained at about the same proportional cost, sold for £9,600. From 1744 to 1758 the average annual value of the copper product of Cornwall is stated at from £100,000 to £160,000. The production continued rapidly to increase, until in 1800 it amounted to 55,981 tons of ore, which produced 5,187 tons of metal, worth £550,925. In 1805, 78,452 tons of ore produced 6,234 tons of copper, worth £862,510; and though in subsequent years larger quantities of equally rich ore were produced, the same value was not reached till 1834, when 143,296 tons of ore produced 11,224 tons of copper, worth £887,502. The product of the mines of the United Kingdom since 1847 has been as follows:
The product for 1856 includes that of Cornwall and Devon only; that for 1872 is estimated. In addition to the above, considerable quantities of copper are obtained from pyrites mined in the kingdom. The amount for 1867 was 2,338 tons; 1868, 1,530; 1869, 1,519; 1870 and 1871, about 1,500 tons each. The separate product of Wales in 1866 was about 650 tons; of Ireland, 1,335 tons. The number of mines in the United Kingdom in 1862 was 228; 1863, 222; 1864, 201; 1865, 203; 1866, 173. The average yield of the ore is 7 or 8 per cent. The following tables exhibit the British trade in copper from 1857 to 1871:
|YEARS.||Imports.|| Exports (foreign and |
| Ore and
The relative amounts of ore and regulus imported have been as follows: 1868, 83,334 tons of ore and 30,702 of regulus; 1869, 72,199 and 38,769; 1870, 62,104 and 44,528; 1871, 48,215 and 30,476. Nearly all the regulus and the greater part of the unwrought copper are brought from Chili, while the ore is furnished by various copper-producing countries.
EXPORTS (DOMESTIC PRODUCE).
The exports are to every quarter of the globe, but perhaps India is the most important market.—The most important copper mines in the United States are those on the south shore of Lake Superior, where the metal occurs in the bedded trappean rocks, with interstratified sandstones and conglomerates, which are developed to a greater or less extent in various localities along both sides of the lake, and are everywhere copper-bearing. The copper is almost wholly in the native or metallic state, and occurs in veins cutting the strata, associated with quartz and various spars and crystalline minerals; and also disseminated in the beds of rock, in which the richest and most productive mines of all are now wrought. While in some of the veins masses of pure copper weighing many tons are met with, the copper in the beds is generally in smaller masses or grains. In this state it occurs in the layers of soft amygdaloidal trap, locally known as ash beds; while in other cases the pure metal appears as the cementing material of conglomerates or breccias made up of the ruins of red feldspar porphyry rocks belonging to an older formation. Remarkable examples of this latter mode of occurrence are seen in the Boston and Albany mine and the Calumet and Hecla mine, the latter of which yielded in 1872 the enormous amount of 8,000 tons of fine copper, or about one tenth of the entire product of the globe. The working of these mines of Lake Superior commenced in 1845, and from that period up to 1858 the entire production of the whole region amounted to a little over 16,000 tons. The copper is extracted by crushing and washing the rock, and is then in a nearly pure state, requiring only to be melted down to ingot copper. There are evidences that mines were worked in this region ages since by a primitive people who had only stone tools for their work. A copper region of great importance occurs in adjacent parts of the states of Virginia, North Carolina, Tennessee, and Georgia, where sulphuretted ores are found in crystalline schists. For several years previous to 1861 the numerous mines in these regions were wrought in an imperfect manner; but the civil war, together with the great depression in the price of copper which followed up to 1871, has caused these mines to be for the most part abandoned, with the exception of those of Ducktown, Tennessee, which yield large quantities of ores that are smelted on the spot. With the present augmented price of copper, and with the aid of improved processes for extraction of the metal from its ores, this region may become a second Cornwall. The deposits of copper ore in the mesozoic sandstones of Connecticut and New Jersey were formerly worked to a considerable extent. From those of Belleville, in the latter state, large quantities of ore were shipped to England as early as 1731. From the irregularity of these deposits, and from the fact that part of the metal is disseminated through the sandstones in an oxidized condition, and not easily extracted by the ordinary smelting processes, these mines have been abandoned. Very lately, however, rich deposits of valuable copper ore have been opened in these sandstones in Chester co., Pa. According to the census of 1870, there were in the United States 40 copper-mining establishments, with 93 steam engines of 6,318 horse power, 3 water wheels of 70 horse power, and 5,404 hands, of whom 2,157 were employed above ground, and 3,247 under ground; capital invested, $7,789,374; wages paid, $2,706,264; value of materials, $586,844; value of product, $5,201,312. The mines were distributed as follows:
|Hands.||Capital.|| Value of |
- Also 3 water wheels of 70 horse power.
The more important of the Maryland mines is in Frederick co.; the other is in Carroll co. The Nevada mine is in Humboldt co., the North Carolina mine in Chatham co., the Tennessee mines in Polk co., and the Vermont mines in Orange co. Of the Michigan mines, 11 are in Houghton co., product $3,231,888; 6 in Keweenaw co., product $823,477; and 10 in Ontonagon co., product $256,802. The following table exhibits the product of the Lake Superior mines since 1858, in tons of 2,000 lbs.:
The product of Vermont for 1872 was between 400 and 500 tons; of Tennessee, about 750; and of the United States, nearly 14,000. The imports of copper ore for the year ending June 30, 1872, amounted to 1,355½ tons (2,240 lbs.) valued at $85,622; of unmanufactured copper, 2,280 tons, worth $1,040,458; the manufactures of copper imported were valued at $800,478. Of the ore, 1,091 tons were from Chili, and 248½ from Canada; of the copper, 1,671 tons came from England, 290 from Cuba, 123 from the British West Indies, and 115 from Chili. The exports of domestic ore were 1,778 tons, worth $101,752; of domestic copper, 120 tons, worth $64,844; the value of domestic manufactures of copper exported was $121,139. The exports of foreign copper and ore were valued at $7,406. The imports of brass and brass manufactures were valued at $173,515; domestic exports, $229,458; foreign exports, $1,966. The production of Canada and Newfoundland may be seen from the imports of ore and regulus into Great Britain from those colonies. The imports from the Dominion of Canada in 1867 were 1,062 tons, worth $51,155; in 1868, 5,270 tons, worth $277,435; in 1869, 3,152 tons, worth $97,335; in 1870, 2,907 tons, worth $191,830; in 1871, 2,083 tons, worth $153,670. From Newfoundland were imported in 1867, 4,120 tons, worth $189,849; in 1868, 8,061 tons, worth $254,325; in 1869, 6,237 tons, worth $159,220; in 1870, 4,162 tons, worth $259,570; in 1871, 1,887 tons, worth $91,375.—There are important copper mines near Santiago in Cuba, from which about 25,000 tons of ore, averaging 16 per cent. of metal, were shipped to England in 1850. The shipments of ore and regulus in 1867 were 7,257 tons, worth $477,150; in 1868, 10,861 tons, worth $744,445; in 1869, 3,869 tons, worth $298,645. The working of the mines was interrupted by the insurrection, and in 1870 and 1871 the shipments amounted to only a few hundred tons.—Chili is the chief copper-producing country of the world. In 1853 the total copper product was 55,700 tons, of which Chili yielded 14,000 tons, or 25 per cent.; while at present that country produces about one half of all the copper mined on the globe. The exports of copper from Chili for a series of years have been:
The value of the exports in 1870 was: bars, $8,067,178; regulus, $4,250,898; ore, $204,967; total, $12,523,043. The total product of the country is estimated as follows: in 1868, 46,500 tons; 1869, 55,000; 1870, 48,600; 1871, 44,900; 1872, 40,500. The mines at Corocoro, 15 leagues S. W. of La Paz, in Bolivia, yield abundantly, though without machinery for drainage or working. The native copper of the deposit, disseminated in sandstone, is extracted by crushing and washing. The product, known in commerce as barilla, was in 1869 from 3,000 to 3,500 tons of ore. Small quantities of copper are shipped from Peru to Great Britain.—The most productive mines of Australia are in South Australia, the largest being the Moonta and Wallaroo mines, on Yorke peninsula, which employ from 2,000 to 3,000 miners, and the Burra-Burra mine, employing about 1,000 hands. The exports from the colony of fine copper and ore from 1862 to 1871 were:
|YEARS.|| Fine copper,
The value of the copper exports in 1871 was £648,569. In New South Wales in 1872 there were 18 copper mines, with a nominal capital of £831,000, and a subscribed capital of £460,240. The product of 1871 was 667 tons of copper, valued at £44,123; exports, 1,350 tons of raw copper, worth £87,575, and 1,370 tons of ore, worth £14,264. The imports into Great Britain from Victoria from 1867 to 1871 were:
|Ore and regulus, tons||5,477||8,488||6,666||8,125||3,522|
|Unwrought and partly wrought copper, tons||763||281||1,085||445||1,202|
Small quantities of copper are also produced in West Australia.—There are copper mines in the Taurus, in Persia, India, Cochin China, and Japan. From the last named country considerable quantities are shipped to China and elsewhere in the East, the exports in 1870 from Hiogo and Osaka amounting to 1,290 tons, worth $426,375. Copper is likewise found in Morocco, in South Africa, and on the W. coast of that continent. The imports of ore and regulus into Great Britain from the Cape of Good Hope in 1867 were 5,935 tons, worth £108,534; in 1868, 2,843 tons, worth £62,407; in 1869, 4,628 tons, worth £92,155; in 1870, 6,926 tons, worth £118,155; in 1871, 6,414 tons, worth £143,812.—The total production of the world at different periods has been estimated as follows: in 1830, 25,500 tons; in 1840, 41,000 tons; in 1850, 54,700 tons. Simonin, in his “Underground Life,” calculates the yield in 1865 to have been 65,000 tons, worth $500 a ton.