一、引言白银厂在兰州北东北约百公里,为甘肃最大硫化矿产地。矿区为南山系变质岩分布之区。原生矿床为含黄铁矿片岩,夹于变质岩层间。走向近北西西,倾斜向北。因次生风化作用,上部变为赤铁矿体,所含硫质及一部铁质铜质等流至下部,与 I. INTRODUCTION Baiyin Plant is about 100 kilometers northeast of Lanzhou and is the largest sulphide ore producing place in Gansu. The mining area is the area where the Nanshan metamorphic rocks are distributed. Primary deposits are pyrite-bearing schist, sandwiched between metamorphic rocks. Toward the North West, tilt north. Due to secondary weathering, the upper part becomes a hematite ore body, the sulfur content and an iron bronze flow to the lower part, and