含金银褐铁矿直接碱性浸出预分离锰银

The Pre-Separation Between Manganese and Silver of Limonite Contained Gold and Silver Via Direct Alkaline Leaching Method

摘要:

云南某矿中的银多数以类质同象或微细粒包裹体存在于褐铁矿和铅硬锰矿中，直接采用氰化浸出其浸出率仅为30.26%。为提高银的氰化浸出率，采用直接碱性浸出法对矿物进行锰、银预分离实验，研究了不同反应条件对浸出的影响，以确立最优的工艺流程。结果表明，在浸出液中铵根的浓度为1.5 mol?L^-1、浓氨水为1.5 mL（在浸出液中的浓度为0.0195 mol?L^-1）、还原剂铜丝4 g、液固比为3:1的条件下，常温下反应4 h后，锰的浸出率为47.2%，而银不被浸出，实现了银和锰预分离。经碱浸后的渣再进行氰化浸出，银的氰化浸出率可提升至71.66%。该方法原材料价廉易得、操作简单、环境污染小，可在短时间内较好地实现锰和银的分离回收，具有较高的综合经济价值。

Abstract:

In a certain mineral resource Yunnan， most silver exists in limonite and lead psilomelane in forms of isomorphism or microgranular enclaves， and the direct cyanide leaching rate is only about 30.26%. The direct alkaline leaching method was used to pre-separate manganese and silver from minerals to improve the cyanide leaching rate of silver. The influence of different reaction conditions on leaching was studied， and finally the optimal process flow was established. The results show that， when the concentration of ammonium in the leaching solution is 1.5 mol?L^-1， adding 1.5 mL concentrated aqueous ammonia （0.0195 mol?L^-1 in the leaching solution） and 4 g reductant Cu and react at room temperature for 4 hours with a liquid-solid ratio of 3∶1， the leaching rate of manganese is 47.2%， the silver is not leached， and the pre-separation of silver and manganese is realized. The residue after alkaline leaching is then cyanide leached， and the cyanide leaching rate of silver can be increased to 71.66%. This method has the advantages of cheap and easy-to-obtain raw materials， simple operation， and little environmental pollution， and can realize effective separation and recovery of manganese and silver in a short period of time， has high comprehensive economic value. This method utilizes cheap and easy-to-obtain raw materials， has simple operation and little environmental pollution， and can effectively separate and recover manganese and silver in a short time， and therefore has high comprehensive economic values.