复杂金精矿浸铜渣预处理工艺

Pre-treatment of Copper Leaching Residue of Complex Gold Concentration

对复杂金精矿浸铜渣硫酸和氟化氢铵预处理工艺进行研究,考察了硫酸与氟化氢铵摩尔浓度比值(R_(S/A))、摩尔浓度、反应液固比、反应时间、反应温度、搅拌速度对金银提取率的影响。结果表明,R_(S/A)和硫酸与氟化氢铵摩尔浓度是影响金银提取率的关键因素,在R_(S/A)=1/1,其摩尔浓度值升高,金、银的提取率可以得到显著提高。浸铜渣经预处理后,包裹物遭到破坏,出现蜂窝状孔隙,硅含量由原来的33.28%降低到5.49%。最佳预处理条件:R_(S/A)=1/1、摩尔浓度值1.5mol/L、反应液固比5∶1、反应时间2h、反应温度298K、搅拌速度250r/min。氰化条件:反应液固比4∶1、pH=10.5、氰化钠浓度4‰、搅拌速度300r/min、反应时间72h、反应温度298 K,此条件下,金、银的提取率分别为98.20%、95.77%,氰化残渣中金、银含量分别小于1.3g/t、50g/t。

Vitriol and ammonium hydrogen fluoride pre-treatment process of copper leaching residue of complex gold concentrate was studied.Effects of molar concentration ratio of sulfuric acid and ammonium hydrogen fluoride(RS/A),molar concentration,L/S,reaction time,reaction temperature,and stirring speed on extraction rate of gold and silver were investigated.The results show that RS/A and molar concentration of sulfuric acid and ammonium hydrogen fluoride are the key factors impacting extraction rate of gold and silver.When RS/A=1/1,extraction rate of gold and silver can be improved significantly with increase of molar concentration of sulfuric acid and ammonium hydrogen fluoride.Inclusions of copper leaching residue are destructed and honeycomb pores appear,and silicon content drops from 33.28%to 5.49%in pre-treatment process.The optimum pretreatment conditions include RS/A=1/1,molar concentration of sulfuric acid and ammonium hydrogen fluoride of 1.5 mol/L,L/S=5/1,reaction time of 2 h,reaction temperature of 298 K,and stirring speed of 250 r/min.Cyanidation conditions include L/S=4/1,pH value of 10.5,sodium cyanide concentration of 4‰,stirring speed of 300 r/min,reaction time of72 h,and reaction temperature of 298 K.Extraction rate of gold and silver is 98.20%and 95.77%respectively under the above-mentioned conditions,and content of gold and silver in cyanide residue is less than 1.3 g/t and 50 g/t respectively.