高温复杂多金属硫化矿电位-pH图

High-temperature Complex Polymetallic Sulphide Ore Potential-pH Diagram

在湿法冶金过程中,为了提高反应速度、浸出率及减少环境污染,加压酸浸对金属硫化矿处理的应用越来越广。在对硫化物加压浸出过程热力学进行分析时,一般通过硫化物-水系电位-pH图来分析浸出的可能性及产物。通过对不同硫化物-水系的热力学计算,绘制了25、150℃下PbS-H_2O系、ZnS-H_2O系、FeS_2-H_2O系、CuFeS_2-H_2O系电位-pH图,并比较了25℃和150℃下各Me_mS_n的浸出电位值。得出复杂硫化矿中最容易浸出的是闪锌矿,各种铜的硫化物较难浸出,黄铜矿的浸出较容易,但黄铜矿的第一步浸出只是生成CuS和Fe^(2+),黄铁矿比铜蓝和辉铜矿较容易浸出,而比方铅矿困难。以上研究结果,不仅可为单一硫化物的加压浸出提供热力学依据,也可为含铜、铅、锌、铁的复杂多金属硫化物精矿直接高温加压浸出提供热力学依据。

In the process of hydrometallurgy,in order to increase the reaction rate,leaching rate and reduce environmental pollution,the application of acid leaching under pressure to metal sulfide ore is more and more widely used.In the thermodynamic analysis of sulfide-pressure leaching process,the possibility and product of leaching are generally analyzed by potential-pH diagram in sulfide-water system.Through the thermodynamic calculation of different sulfide-water systems,the potential-pH diagrams of PbS-H2O,ZnS-H2O,FeS2-H2O,and CuFeS2-H2O at 25℃and 150℃were drawn.The leaching potential values of various MemSn under 25°C and 150°C were compared.It was concluded that the copper sulfides ore were difficult to leach out,the leaching of chalcopyrite was easier than other copper sulfides,which the first step of chalcopyrite leaching was only to form CuS and Fe2+.Pyrite is easier to leach than copper sulfides,but more difficult than galena,and sphalerite is the most easily to be leached.The above results not only provide thermodynamic basis for pressure leaching of single sulfide,but also provide thermodynamic basis for direct high-temperature pressure leaching of complex polymetallic sulphide concentrate containing copper,lead,zinc and iron.