含铁氰化渣中铁的浸出性能和热力学研究

Thermodynamic Analysis and Leaching Performance of Iron Extraction from Cyanide Tailings

以含铁氰化渣为原料进行了酸浸试验,考察了浸出酸用量系数、浸出温度和浸出时间对铁浸出率的影响。热力学分析结果表明,氰化渣中的铁氧化物在高温、浓酸条件下以可溶性铁离子形式进入浸出液。试验结果表明:在硫酸浓度45%、硫酸用量系数(硫酸理论用量的倍数)1.5、盐酸用量0.1 m L/g、体系沸点温度下、液固比3∶1、浸出时间4 h的最佳条件下,铁浸出率为96.53%;然后采用胶体分散法制备聚合硫酸铁回收浸出液中的铁。浸出渣氰化浸出试验结果表明,金浸出率达到98.82%,为实现氰化渣的综合利用提供了一种新的处理工艺。

The test on acid leaching of cyanide tailings was conducted to investigate effects of H2SO4 dosage,leaching time and temperature on the iron leaching rate. The thermodynamic analysis indicated that the iron oxide in the cyanide tailings can be leached into the leaching solution in the form of soluble iron ions at high temperature with the concentrated acid. It is found that the leaching process with H2SO4 at the concentration of 45% and in an amount of 1.5 times the theoretical value,with HCl at the dosage of 0. 1 m L / g,liquid and solid ratio of 3∶ 1,at the temperature of boiling point of the system for 4 h,can result in the leaching rate of Fe up to 96. 53%. The Fe in the leaching solution was then recovered by the polymeric ferric sulfate solution that was prepared by dispersing Fe（ OH）3colloid,and the residue was taken for a cyanide leaching test,resulting in the leaching rate of Au up to 98. 82%. It is concluded that such new process can provide an alternative way for the comprehensive utilization of cyanide tailings.