生物-化学两级循环反应器预处理坪定难处理金矿石

试验研究了矿石粒度、温度、Fe^3＋浓度等因素对生物-化学两级循环反应器预处理甘肃坪定难处理金矿石效果的影响。试验研究结果表明：在70℃、Fe^3＋质量浓度为6g/L（6K）、矿石粒度-74μm的条件下，该矿石经生物-化学两级循环反应器氧化预处理72h后，砷的浸出率可达到17．7％以上；预处理5d后的氧化矿样金的氰化浸出率高达91．76％。而用传统生物氧化法预处理10d，金的氰化浸出率为80．31％。试验结果还显示，温度的升高、Fe^3＋浓度的增加，可促进化学反应器中Fe^3＋对矿物的氧化，且矿石的粒度细预处理效果好。

Pretreatment of Pingding refractory gold ore by continuous two-stage bio-chemical reactor in Gansu

In this paper, the pretreatment of arsenic-bearing refractory gold ore, which was collected from Ping-ding in Gasnsu province, was carried out by bioleaching in a novel continuous two-stage bio-chemical reactor. The effects of processing parameters, i.e. ore particle size, temperature and Fe3+ concentration et al. , were investigated. Results showed that an arsenic extraction rate of 17.7 % could be obtained for 72 h pretreatment under the conditions of 70℃, 6 g/L of Fe3+(6 K) and-74 μm of particles size. Furthermore, the leaching rate of gold from the oxida-tion ores by cyanidation was higher than 91% after 5 days' pretreatment. This was markedly higher than that of tradi-tional biological pretreatment even for 10 days, which was 80.31%. Results also demonstrated that the leaching rate of arsenic was favored by the rise of temperature, Fe3+ concentration, and also by the decrease in ore particle size.