Mo(W)-H_2O系溶液化学行为研究

The Chemical Behaviors of Mo(W)-H_2O System Solution

依据Mo(W)-H2O体系中存在的主要电化学反应以及各反应组份的热力学数据,通过在室温下(298 K)的热力学计算,归纳出Mo-H2O系、W-H2O系反应平衡式及其εT和pH的计算式,并绘制出Mo-H2O系与W-H2O系的电位-pH图.图形明确了钨、钼的各种物质形态在不同pH条件下的热力学稳定区以及化学反应可能性,并指出了MoO42-及WO42-的电化学性质差异.结果表明:W-H2O体系总体电位值明显低于Mo-H2O体系电位值,可利用其性质的差异,选择适当的还原剂进行选择性还原,实现钨钼的高效分离.

This paper studies the Mo-H2O system,W-H2O system balanced reaction and εT-pH calculation formula based on the main electrochemical reaction and the thermo-dynamic data of the reaction component in Mo（W）-H2O system.The Mo-H2O system and W-H2O system potential-pH diagram are mapped out through the thermodynamic calculation at room temperature（298 K）.In the graphics,the thermo-dynamic stable region of various substances forms of tungsten and molybdenum under different pH conditions and the possibility of chemical reaction are indicated.The electrochemical properties difference of MoO42-and WO42-are pointed out.The result shows that the potential value of W-H2O system is significantly lower than the value of Mo-H2O system.The phenomenon of the potential value differences can be used to select the appropriate reducing agent for selective reduction.The separation of tungsten and molybdenum can be efficiently practiced.