复杂金精矿焙砂酸浸-氰化工艺的研究及金银物相演变规律

研究了复杂金精矿焙砂酸浸—氰化工艺酸浸分铜工序铜浸出率,以及后续氰化过程金、银浸出率的影响。结果表明:在浸出温度363K、浸出时间3h、硫酸浓度1.0mol/L、搅拌转速300r/min、液固比4∶1的较优条件下,金、银、铜的浸出率分别为93.21%、83.25%、95.57%。硅酸盐包裹是造成银浸出率低的主要原因。无添加剂直接焙烧,氰化渣中硅酸盐包裹银占渣含银总量的60.30%;在焙烧过程中添加氢氧化钠可以有效降低硅酸盐对银的包裹,有效提高银的浸出率,氰化渣中硅酸盐包裹银仅占渣含银总量的27.56%。

Study on Acid Leaching Cyanide Process of Complex Gold Concentrates and Evolution of Gold and Silver Phases

Copper leaching rate of acid leaching-cyanide process in complex gold concentrate calcine acid leaching-cyanide process and leaching rates of gold and silver in subsequent cyanidation process were studied. The results show that leaching rates of gold, silver and copper are 93.21%, 83.25%, and 95.57% separately under the optimum leaching conditions including leaching temperature of 363 K, leaching time of 3 h, sulfuric acid concentration of 1.0 mol/L, stirring speed of 300 r/min, and L/S=4/1. Silicate inclusion is the main cause of low silver leaching rate. Content of silver silicate inclusions is 60.30% of total amount of silver in cyanide residue without additives in roasting process. Sodium hydroxide addition in roasting process can effectively reduce probability of silver silicate inclusion and improve silver leaching rate. Content of silver silicate inclusion is only 27.56% of total amount of silver in cyanide residue in sodium hydroxide roasting process.