Recovery of polymetallic elements from cyanide tailings via reduction smelting  

采用还原熔炼法回收氰化尾渣中的多金属元素

作　　者：Gong-hao LI Fen JIAO Chen LI Si-yu GU Shi-yang LIU Xin WEI 李塨灏;焦芬;李琛;顾丝雨;刘世阳;魏鑫(中南大学资源加工与生物工程学院,长沙410083)

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第3期975-989,共15页中国有色金属学报(英文版)

基　　金：supported by the National Key R&D Program of China(No.2020YFC1909203);the Hunan Provincial Innovation Project,China(No.CX20230213)。

摘　　要：A process for treating cyanide tailings was proposed.The process essentially implicates reduction smelting which involves volatilizing silver,lead,and zinc in the cyanide tailings at high temperatures.Meanwhile,gold and copper combine with the reduced iron to form a metal phase,allowing for the simultaneous recovery of polymetallic elements.The experimental results indicate that the process works optimally with a coke powder of 7.5 wt.%,an alkalinity of 1.0,a melting temperature of 1450℃,and a melting time of 60 min.Under these conditions,more than 99% of gold,77% of copper and 94% of iron are incorporated into pig iron.In the meantime,the volatilization rate of silver exceeds 90%,while lead and zinc are essentially completely volatilized.The primary component of the by-product smelting slag is akermanite,which exhibits lower leaching toxicity than the national standard and belongs to general solid waste.Additionally,taking the trapping process of iron to copper as a case study,the mechanism of iron trapping is methodically examined and divided into three processes:smelting reduction,migration capture,and condensation deposition.提出了一种处理氰化尾渣的方法。还原熔炼使氰化尾渣中的银、铅和锌在高温下挥发,而金和铜与还原态铁结合形成金属相,实现多金属元素的共同回收。实验结果表明,最佳工艺条件为焦粉用量7.5%(质量分数)、碱度1.0、熔炼温度1450℃以及熔炼时间60 min。此条件下超过99%的金、77%的铜和94%的铁进入生铁,同时银的挥发率超过90%,铅和锌基本完全挥发。副产物熔炼渣的主要成分为钙镁黄长石,浸出毒性低于国家标准,属于一般固废。此外,以铁对铜的捕集过程为例,分析铁的捕获机理,并将其分为熔炼还原、迁移捕集和凝聚沉积3个阶段。

关 键 词：cyanide tailings gold tailings reduction smelting valuable element recovery 

分 类 号：O64[理学—物理化学]