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Home > Outline of Japan's Industrial Pollution Abatement > Preventative Measures Against Water Pollution Jinzu River, Toyama Prefecture > 2) History of Kamioka Mines

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Update:April 1, 2010

2) History of Kamioka Mines


Records recount that gold was refined from the Kamioka Mines as far back as 710, but it is said that full-scale mining for ore started in 1589 when the Mosumi and Wasayama silver mines were discovered in the now central part of the mining region. The silver mining boom did not last long, and the mines were placed under the direct control of the Tokugawa shogunate in 1692. The syogunate continued to refine silver, copper and zinc until their demise.
After the Meiji Restoration of 1868, the new government ordered all mines of the Kamioka mining region placed under the direction of the Mitsui as a means for restoring production. Mitsui began to produce lead and zinc with new technology from western Europe and modern management in 1887. Demand for lead and zinc grew when the Russo-Japanese War and WW- I broke out in 1904 and 1914 respectively. By 1905 it was said that the Kamioka Mines ranked amongst the world's best, owing to the sharp rise in the scale of production (the production of zinc began which had been discarded as an impurity up until that time),
Futhermore, the volume of extracted ore increased 4 times over as military because of the nation was in a state of war from 1935 to 1945, One-site production of zinc and sulfuric acid began in 1943, and cadmium in 1944.
After the war, Japan's famed Zaibatsu (plutocratic business groups) were dissolved in 1950. The metal division of Mitsui Mining (Co., Ltd.) was separated from the mother organization and reorganized as the Mitsui Mining and Smelting Co., Ltd. From 1950 to 1975, during the period of high postwar economic growth, productivity grew some 10 times over. Thereafter, as one mine after another closed because of the oil crisis and appreciating yen, the present Kamioka Mining Co., Ltd. broke off as an independent company in 1985. It is currently operating sa an internationally competitive mine (Fig.1-3 & 1-4).