硫化法除钼过程中杂质砷的行为

摘要

According to the known thermodynamic data, the sulfidizing behavior of arsenic complexes in the sulfidizing separation of tungsten and molybdenum was calculated, and the distribution graphs of various arsenic ions vs pH and arsenic ion vs molar ratio of S to As were drawn. The influence law of pH and sulfidizing agent dosage on sulfidizing behavior of arsenic were discussed. The results show that, under certain conditions, the arsenic sulfide compounds can thoroughly be transformed into AsS43- in thermodynamics. The pH value of the solution is the key factor in sulfidizing effect, and the extent of arsenic sulfidizing increases with the increase of the sulfidizing agent dosage. More than 99% of As can be sulfidized to AsS43- under the conditions of pH 7.5-9.5 and mole ratio of S to As above 6.%根据已有的热力学数据,对钨钼硫化分离过程中杂质砷的各种配合物进行计算,绘制溶液中各含砷离子随pH及S与As的浓度比[S]/[As]变化的分布曲线,分析溶液中pH及硫化剂用量对砷硫化行为的影响规律.研究结果表明:控制一定的条件,将溶液中的含砷化合物较彻底地硫化为AsS43-在热力学上是完全可能的；溶液的pH是影响硫化效果的关键因素,并且砷的硫化程度随硫化剂用量的增加而增大；在pH=7.5～9.5范围内,硫用量[S]/[As]＞6时可使99％以上的As硫化为AsS43-.