最近15～20年,许多黑色和有色冶金矿山,由于矿床二次开采,增加了地下和露天开采的矿石产量。克里沃罗格矿区二次开采的铁矿石,1965年为64.5万t,1975年为82.3万t,1980年为190.2万t。英古列茨采选公司中央矿井1981～1985年二次开采的矿石量为计划采矿量的60～80％。这些年,捷尔任斯基、基洛夫卡尔·李卜克内西和共产国际等矿务局有10个矿井进行了铁矿体的二次开采,地下采矿量约为1500万t,包括露天开 In the last 15 to 20 years, many black and non-ferrous metallurgical mines have increased production of underground and open-pit ore due to secondary mining. The second mining of iron ore in the Krivoy Rug mine area was 645,000 tons in 1965, 823,000 tons in 1975 and 1,902,000 tons in 1980. The Anglo-Gulz Mining Company Central Mines recovered from 1981 to 1985 an amount of 60 to 80% of the planned mining volume. In these years, 10 mining mines such as Tairinski, Kirovka-Liebknecht and Comintern carried out secondary mining of iron ore mines with an underground mining volume of about 15 million tons, including Open in the open