论文部分内容阅读
针对钨冶炼过程中采用选择性沉淀法除钼后溶液中铜浓度“反常”偏高的现象,利用同时平衡原理,对该溶液体系中的Cu-NH3-C l-S复杂络合平衡进行了热力学计算,并根据结果绘制了有关平衡图,同时结合生产实际进行了分析与解释。结果表明,选择性沉淀法除钼后溶液中的铜可与HS-,NH3,C l-和OH-等阴离子形成多种复杂络合离子,但大多数铜络合离子浓度非常低,对溶液中总铜浓度影响很小;造成铜的“反常”偏高的主要原因在于铜与HS-形成的Cu(HS)3-和CuS(HS)33-络离子,并且在计算条件下,该类络离子的浓度随pH值及溶液中[S]的增加而迅速增加。最后根据分析结果,提出了避免铜杂质超标的对策,主要方法如下:(1)在不造成大量钨损的前提下尽可能降低溶液硫化的pH值或在保证硫化深度的前提下尽可能降低硫化剂的用量,可使除钼后溶液中铜浓度降低;(2)可以在除钼后向溶液中加入氧化剂(如H2O2)将溶液中剩余的硫氧化成SO24-,使其无法与铜络合从而减少溶液中的铜浓度;(3)因铜络离子均以络阴离子的形式存在,可通过溶剂萃取或阴离子交换树脂吸附,将含铜络阴离子除去,从而降低溶液中的铜浓度。
Aiming at the phenomenon that the Cu concentration in the solution after the removal of molybdenum by the selective precipitation method is abnormally high in the process of tungsten smelting, the complex complexation of Cu-NH3-C1S in the solution system is carried out by using the principle of simultaneous equilibrium According to the thermodynamic calculation, the equilibrium diagram is drawn according to the results, and the analysis and explanation are combined with the actual production. The results show that the copper in the solution after the selective precipitation method can form complex complex ions with the anions such as HS-, NH3, C l- and OH-, but the concentration of most copper complex ions is very low. For the solution The main reason for the high copper concentration is copper (HS) 3- and CuS (HS) 33- complex formed by copper and HS-, and under the condition of calculation, The concentration of this class of ions increases rapidly with increasing pH and solution [S]. Finally, based on the analysis results, the countermeasures to avoid excessive copper impurities are proposed. The main methods are as follows: (1) To reduce the sulfide value of the solution as much as possible without causing large amount of tungsten loss or to reduce the vulcanization The dosage of the agent can reduce the concentration of copper in the solution after removing the molybdenum; (2) the remaining sulfur in the solution can be oxidized to SO24- by adding an oxidizing agent (such as H2O2) Thereby reducing the concentration of copper in the solution. (3) Since the copper ions are in the form of complex anions, the copper-containing complex anion can be removed by solvent extraction or anion exchange resin adsorption to reduce the concentration of copper in the solution.