响应曲面法优化金精矿生物氧化渣非氰浸金过程

采用单因素法和响应曲面法对活性炭-硫氰酸铵浸出金精矿生物氧化渣过程进行优化研究。结果表明,在硫氰酸铵浸金过程中加入活性炭能进一步提高金浸出率; 金浸出率随硫氰酸铵浓度和pH值增加而升高、随着活性炭添加量增加先升高后降低; 硫氰酸铵浓度和pH值的交互作用对金浸出率影响明显,各因素对金浸出的影响程度为:硫氰酸铵浓度>pH值>活性炭添加量; 在硫氰酸铵浓度0.85 mol/L、pH=11.58、活性炭添加量3.37 g/L的适宜工艺条件下,金浸出率预测值为93.93%,平均实验值为94.00%,二者误差值仅0.07%,模型能够对金浸出率实现准确地分析和预测。

Optimization of Cyanide-Free Gold Leaching Process by Response Surface Methodology for Bio-oxidation Residue of Gold Concentrate

The leaching process of bio-oxidation residue of gold concentrate with activated carbon-ammonium thiocyanate was optimized by using single factor method and response surface methodology. The results show that an addition of activated carbon in the process of gold leaching with ammonium thiocyanate can further improve the leaching rate of gold. It is shown that the gold leaching rate can increase with the increase of ammonium thiocyanate concentration and pH value, while decreases after an initial increase  by increasing  the adding amount of activated carbon. And the combined effect of ammonium thiocyanate concentration and pH value can bring obvious influence to gold leaching rate. The influence degree of each factor on gold leaching rate is in the following descending order: ammonium thiocyanate concentration> pH value> adding amount of activated carbon. Under the following appropriate processing conditions, including the concentration of ammonium thiocyanate at 0.85 mol/L, pH of 11.58 and addition of 3.37 g/L activated carbon, the gold leaching rate was predicted to be 93.93%. While the gold leaching rate obtained from the experiments was 94.00% on average, with the error just 0.07%. It is concluded that this model can be used to accurately analyze and predict  gold leaching rate.