碳酸钠选择性浸出钨钼混合矿的热力学  

Thermodynamic analysis of powellite selective leaching by soda

作　　者：吴金玲[1] 李江涛[1] 刘旭恒[1] 陈星宇[1] 何利华[1] 

机构地区：[1]中南大学冶金与环境学院,长沙410083

出　　处：《有色金属科学与工程》2013年第5期33-38,共6页Nonferrous Metals Science and Engineering

基　　金：国家科技支撑计划资助项目(2012BAB10B04)

摘　　要：针对碳酸钠选择性浸出钨钼混合矿的理论问题,选取25℃条件下的热力学数据,计算并绘制了不同总碳浓度条件下的Ca-W-Mo-C-H2O体系主要离子的浓度对数图,以及溶液中总钨、总钼的浓度与pH关系图,分析了CO32-浓度以及pH值对钨酸钙和钼酸钙混合体系选择性浸出的影响.结果表明:溶液中钨钼饱和浓度随着CO32-浓度的增加而增加,且钼的饱和浓度是钨饱和浓度的1.85倍;在总碳浓度一定的条件下,CaMoO4比CaWO4更易分解;为了避免低pH值下CO32-以HCO3-形式存在导致钨钼浸出率降低,溶液需要保持较高的碱度.通过控制溶液总碳浓度及pH值,可以达到钨钼混合矿选择性浸出钼的目的.For theoretical issues of powellite soda selective leaching, equilibrium diagrams of Ca- W-Mo-C-H2O system were drawn on the basis of thermodynamic data at 25 ℃. Total concentration of ions （W, Mo）-pH relationship diagrams were depicted. The effects of system pH value and total carbon-containing ions concen-tration on mixed system selective leaching were analyzed. Along with the concentration of CO 32-increasing, the total （W, Mo）concentration in the solution was added. The saturation concentration of Mo is about 1.85 times that of W. Under a certain total carbon concentration, CaMoO4 is more likely to decompose than CaWO4. In ad-dition, the high pH value should be maintained to avoid an unexpected abundant of HCO 3- instead of CO32-mainly existing under low pH value, leading to the decrease of W and Mo leaching rate. By controlling the total carbon concentration and pH value of the solution, Mo can be obtained by the effects of W and Mo selective leaching.

关 键 词：钨钼混合矿 碳酸钠 热力学计算 选择性浸出 

分 类 号：TF841.1[冶金工程—有色金属冶金] TF803.13