生物-化学两级循环反应器预处理坪定难处理金矿石

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

试验研究了矿石粒度、温度、Fe3+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℃、Fe3+质量浓度为6 g/L(6 K)、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72 h后,砷的浸出率可达到17.7%以上;预处理5 d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10 d,金的氰化浸出率为80.31%。试验结果还显示,温度的升高、Fe3+浓度的增加,可促进化学反应器中Fe3+对矿物的氧化,且矿石的粒度细预处理效果好。

In this paper, the pretreatment of arsenic-bearing refractory gold ore, which was collected from Pingding 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 Fe^3＋ 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 Fe^3＋ （6 K） and -74μm of particles size. Furthermore, the leaching rate of gold from the oxidation ores by cyanidation was higher than 91% after 5 days＇ pretreatment. This was markedly higher than that of traditional 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, Fe^3＋ concentration, and also by the decrease in ore particle size.