含多金属复杂金精矿焙烧预处理-提取金、银、铜研究  

Roasting Pretreatment of Poly-Metallic and Complex Gold Concentrate to Extract Gold,Silver and Copper

作　　者：王瑞祥[1,2] 曾斌[1] 余攀[1] 王志刚[2] 阮建国[2] 谢博毅[1] 

机构地区：[1]江西理工大学冶金与化学工程学院,江西赣州341000 [2]中国瑞林工程技术有限公司,江西南昌330031

出　　处：《稀有金属》2014年第1期86-92,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51164011);福建省区域科技重大合作项目(2011H4025);国家高技术研究发展计划(863计划)(2013AA064001)资助项目

摘　　要：采用焙烧-酸浸-氰化法从某含多金属复杂金精矿中提取金、银、铜,考察了焙烧预处理气氛、温度、时间、氢氧化钠加入量4个因素对金、银、铜提取率的影响。结果显示,焙烧气氛是影响金、银、铜提取率的关键因素,在富氧气氛下焙烧预处理,金、银、铜的提取率有显著提高,并确定较优试验条件为:富氧气氛,焙烧温度903 K,焙烧时间3 h,氢氧化钠加入量4%,硫酸浸出,液固比4∶1,硫酸浓度1 mol·L-1,反应温度363 K,反应时间3 h,氰化浸出,液固比4∶1,pH值10.5,氰化钠浓度4‰,反应72 h,此条件下,金、银、铜的提取率分别为94.55%,83.25%,94.75%。银化学物相分析知,添加氢氧化钠焙烧预处理,能够有效降低硅酸盐包裹银的含量。热力学计算知,在T=903 K,加入氢氧化纳焙烧预处理,可以减小ZnO·Fe2O3,CuO·Fe2O3,2ZnO·SiO2,2PbO·SiO2,PbO·SiO2的生成几率,削弱上述物质对金、银的包裹作用,对比不同氧压下的lgpSO2-lgp O2图,知氧分压越高,硫酸化焙烧稳定区域面积越大,有利于硫酸化焙烧进行,从而可以获得更高的金、银、铜的提取率。Gold, silver and copper were extracted from poly-metallic and complex gold concentrate by roasting-acid leaching-cyanide method. The effects of roasting atmosphere, roasting temperature, roasting time, and sodium hydroxide dosage on the extracting rate of gold, silver and copper were investigated. Experimental results showed that the roasting atmosphere was the key factor to impact the ex- traction rate of gold, silver and copper. The extraction rate of gold, silver and copper was improved significantly when roasting pre-treat- ment was performed in oxygen-rich atmosphere. And the optimal conditions were further determined as follows ： rich oxygen, roasting tem- perature of 903 K, roasting time of 3 h, sodium hydroxide dosage of 4 g, liquid to solid ratio of 4：1 in acid leach, sulfuric acid concen- tration of 1 mol＇L-~, reaction temperature of 363 K, reaction time of 3 h, liquid to solid ratio of 4：1 in cyanide leach, pH value of 10. 5, sodium cyanide concentration of 4%o, reaction time of 72 h. Under above-mentioned conditions, the extracting rate of gold, silver and copper were 94.55% , 83.25% , 94.75%, respectively. Silver chemical phase analysis showed that adding sodium hydroxide during roasting pretreatment could obviously reduce the amount of silver encapsulated in silicates. The analysis of thermodynamics calculation data showed that sodium hydroxide played an important role in reducing the generation of zinc ferrite, copper ferrite, positive zinc silicate, positive lead silicate, lead silicate which wrapped around gold and silver during roasting pretreatment. The relationship diagram between oxygen partial pressure and sulfur dioxide partial pressure revealed that the higher the oxygen pressure was, the larger the stable area of sulfation roasting was, the easier the sulfation roasting was, and the higher the extracting rate of gold, silver and copper was.

关 键 词：含多金属复杂金精矿 焙烧气氛 焙烧温度 焙烧时间 热力学 

分 类 号：TF83[冶金工程—有色金属冶金]