上北鉱山における露天掘
1960 年 76 巻 868 号 p. 663-665
詳細
1960 年 76 巻 868 号 p. 663-665
Tne limonite doposits in Kamikita mine are consists of two types of ores, one may be regards oxidation of black-ore; the other may be secondary precipitated from ground water pass through the black-ore bodies.
Open pit mining was open in 1956 and about 150, 000 tons of are were produced.
By the reasons of heavy snow falls and cold weather in winter, anual operating times are only 5 months.(from June to Oct.) On 1959 some mechanization, such as power-shovel, bulldozers, and dump-trucks, were introduced into mining. After then mining expense is cutting downward.
