COPPER
The conditions of copper mining are exactly opposite from those of silver. The Indians used almost no metal except copper, and for three hundred years white men used the old Indian mines and refined the copper by Indian methods. Better methods of mining copper and extracting it from the ores have been employed for the last fifty years, but within a dozen years the refining of copper has been revolutionized by electric methods. An enormous amount has been produced, but production has been kept down on account of the high prices. It is said that if the price could be reduced one-half, ten times as much copper would be used. Most of the uses of copper have arisen in the last twenty-five years. Its greatest use is for electric wiring. Nothing can take its place, and the use is increasing astonishingly.
Copper is used largely in alloys. Bronze is an alloy of copper and tin, and its use has greatly increased in castings, fittings for buildings, tablets, and statues.
A much more useful alloy is brass, made from copper and zinc. Brass is very extensively used for parts of machinery, engines, automobiles, and also for fittings for buildings. Sheet copper is used for sheathing for ships, for boilers, and for various chemical processes carried on by electricity or by acids. Very many of these processes have been discovered within ten or fifteen years, and have largely increased the uses for copper. One of the older uses of copper which is less common now was for cooking utensils. Copper is used by the government for coining one-cent pieces.
No single country compares at present with the United States in the production of copper, but if reports be correct there is enough copper in central Africa to supply the world for years to come. Next to the United States, Spain mines the largest amount at present, and Japan ranks next.
For many years the rate of increase was enormous. In 1845, 224,000 pounds were mined; in 1888, 226,000,000 pounds. Eight years later, in 1896, it had doubled; after another ten years, in 1906, it had doubled that quantity, and reached 918,000,000 pounds. In 1890 we were using three pounds of copper for every man, woman and child in the country. And in 1907, six and one-half pounds.
Michigan, Montana, and Arizona produce the bulk of the copper. Utah, California, Colorado, New Mexico, Wyoming, and Nevada each produce copper in amounts ranging from the 66,000,000 pounds mined in Utah to the 2,000,000 pounds mined in Nevada. It is probable that the use will not increase so rapidly in the near future. Much old copper will be remelted.
There are large areas of copper lands which are now classed as "available" with copper at about its present price of thirteen cents a pound. If the world production should grow so great as to cause a decided drop in the price, much that is now considered available could not be mined at a profit, and the copper supply from this country would be greatly reduced. If, on the other hand, copper should rise to fifteen or twenty cents or higher, the amount of available copper land would be vastly increased. The report on the Conservation of Mineral Resources says in effect: "The copper resources of the United States are believed to be large enough to allow for a number of years for a demand increasing at the rate of 30,000,000 pounds a year. Should this demand continue for a long period the scarcity would be felt and result in a rising price, which would open up a market for these low-grade ores and also cause the use of other metals, like aluminum, to take the place of copper whenever possible."
There is no great waste in the mining of copper, but in the extraction of copper from the ore the waste is often as much as thirty per cent., and it is not easy to avoid this on account of the chemical changes that take place.