栃洞鉱山におけるトラックレス・マイニングを活用した操業の改善, 合理化

Abstract

In 1968, the Trackless Mining System was introduced to Tochibora Mine for the first time in Japan.Since then, the mechanization and the rationalization of each underground work have been carried out with the practical application of this system and we have succeeded in saving operating cost to a large extent.Moreover, the ratio of minor ore deposits occupying for percent of the minable ore reserve has been increasing with the advance of mining large-sized ore deposits. Under the above aggregating mining conditions, waste dilution has been improved without lowering mining efficiency and the grade of crude ore has been raised by the improvement of mining method or by the expanding application of the Mechanized Cut and Fill method.As the result, in spite of the reduction from 4, 800t/day to 3, 200t/day due to the economical depression in 1979, we have reduced the operating costs under the unfavorable conditions of raising labor and other costs. And we have come to be able to carry on the stable mining management, overcoming the unfavorable conditions of low ore grade mining (Ag 19 et, Pb 0.3%, Zn 4.2%), while many of unprofitable metal mines are going to be closed or suspended.