响应曲面法优化黄金氰渣亚硫酸钠-空气氧化法脱氰工艺

Optimization of cyanide removal technology by Na2SO3-Air oxidation of gold cyanide residues using response surface methodology

采用氰化法进行提金处理会产生大量黄金氰渣,对环境安全和人体健康产生严重危害,根据国家标准必须对其进行脱氰处理。使用亚硫酸钠-空气氧化法对某黄金企业产生的黄金氰渣进行脱氰处理,利用响应曲面法探究各因素对脱氰结果的影响及交互作用,进而得到脱氰的最佳工艺条件。结果表明:矿浆初始pH值、亚硫酸钠用量以及反应温度对脱氰结果产生明显影响,空气充入量的影响不大,脱氰反应在开始的15 min内迅速进行,60 min后基本反应完全。对响应曲面模型预测结果进行优化,在最佳条件初始pH值12.90,药剂用量为理论量的3.5倍,反应温度为40℃时对氰渣进行脱氰处理,总氰化物脱除率可达到88.94%,脱氰尾渣毒性浸出液中总氰含量为2.95 mg/L,满足国家标准。

The plenty of toxic gold cyanide residues are produced by the cyanidation process of gold extraction,which are harmful for environmental safety and human health.The cyanide in gold cyanide residues must be removed to reach the national standard.The removal of cyanide in gold cyanide residues by Na2SO3-Air oxidation process was investigated.To obtain the optimum conditions,the effects of reaction factors on cyanide removal efficiency and the significance of interaction between these factors were investigated by response surface method.The results show that the initial pH of slurry,the dose of Na2SO3 and the temperature have significant effects on the cyanide removal efficiency.The effect of air flow is less significant.The cyanide removal process was carried out rapidly within first 15 min,and basically the reaction completes after 60 min.According to the predicted results of response model,the optimum conditions are as follows:initial pH is 12.90,Na2SO3 dose is 3.5 times of the theoretical dose and temperature is 40℃,respectively.Under the optimum conditions,the cyanide removal efficiency is 88.94%,the content of cyanide in toxic leaching solution of residue is 2.95 mg/L,which reaches the national standard.