[125] Plant capacity. Evidently not reached in 1917.
Since the high copper prices of 1916 there was a heavy importation of Chinese copper coins into Japan. In 1917 one concern alone had contracted for 200,000 tons of such coins, which contain about 85 per cent. copper, and the rate of importation at that time would mean 60,000 tons refined copper a year from this secondary source. This development has enabled Japan to make heavy exports of copper.
The collapse of Russia removed one of Japan’s big copper markets. Japan will probably not be able profitably to produce a large exportable surplus of copper unless the price obtained is fairly high compared to quotations ruling in 1912 to 1914. Under normal conditions Japan will supply her own needs for copper with little or nothing to spare.
KOREA (CHOSEN)
The Seoul Mining Co. (Collbran and Bostwick) is producing from contact deposits, one 50 miles and the other 100 miles from a harbor. This American concern is a dominant trading and banking house in Korea and is working mines formerly operated by Koreans. The copper ores are sulphides between limestone and granite. Five hundred tons of 60 per cent. concentrates were shipped from Chosen to the United States in 1917.
CHINA
The present production of China is 2,000 tons a year, and the chief deposits are in Yunnan Province. A great many localities are reported to show copper ores, mainly cupriferous pyrite in very old schists, or in Permian basalt. The latter deposits are too small for modern methods. In the last hundred years, lack of wood to make charcoal has restricted output to a nominal amount. Small seams of native copper are highly esteemed by the natives. The ores are carefully hand-picked, and the small-scale methods are wasteful.
The Tungschuanfu mine, Yunnan, the chief mine in China, has a yearly output of about 1,000 tons of copper. The district has been worked for hundreds of and probably is very rich. The ores, replacements in limestone and veins in shale, are 8 per cent. copper and the reserves are large. The Yaoki Kansu government smelter is a modern plant with a capacity of four tons of copper a day.
There are several other mines, all controlled by the government. Outside engineers have reported favorably on some of them, but the government closely regulates copper mining in China because it affects currency and government profits on coinage of copper. There are also some copper mines worked with the contact iron deposits of China (formed by contact action of diorite); and deposits of malachite in Triassic sandstone are worked at several points.