【作者】 陈聪；

【导师】 曾德文；

【作者基本信息】 中南大学 ， 物理化学， 2012， 硕士

【摘要】 湿法炼锌过程中钙结晶危害是湿法冶金领域亟待解决的难题。为了揭示钙结晶在湿法炼锌过程中形成原因和结晶机理,提出合理的除钙方法,本文进行了以下研究：测定了二水硫酸钙和自制沉钙剂在实验室配制硫酸锌溶液(含锌98～194g/L)中不同温度下(25～80℃)的溶解度。结果表明,一定温度下,二水硫酸钙和自制沉钙剂的溶解度都随着硫酸锌浓度的增加而减小；在一定浓度的硫酸锌溶液中,二水硫酸钙溶解度随温度的升高而增加,而自制沉钙剂溶解度随温度的升高而减小。进一步对二水硫酸钙和自制沉钙剂在湿法炼锌厂现场取样的除铜镉净化液这一复杂电解质溶液中的溶解度进行研究,结果表明二水硫酸钙和自制沉钙剂在现场溶液中与在实验室配制硫酸锌溶液中的溶解度行为一致。研究了沉钙剂沉钙剂加入量及搅拌时间对现场取样的除铜镉净化液中钙离子去除效果。研究发现,湿法炼锌过程中去除钙结晶的最优条件是：温度80℃、溶液pH5.2、自制沉钙剂沉钙剂加入量5.0g/L搅拌时间1～2h。在此条件下可以将湿法炼锌体系中钙离子浓度降低到350ppm左右,达到良好的除钙效果。基于以上研究,提出一种简便实用的避免湿法炼锌过程中钙结晶的解决方案。更多还原

【Abstract】 To reduce the harm of calcium sulfate scaling in zinc hydrometallurgical process is still a worldwide tough task. In order to understand the crystallization mechanism and develop an economic and efficient method to avoid the scale formation of calcium sulfate, we have carried out following work:The solubility isotherms of gypsum and self-made calcium removing reagent at different temperatures (25～80℃) in the simulated zinc sulfate solution (98-194g/L) were determined by an isothermal method. The results showed that the solubility of dihydrate calcium sulfate and self-made calcium removing reagent decreases with increasing zinc sulfate concentration at a certain temperature. However, in a certain zinc sulfate concentration solution, the solubility of dihydrate calcium sulfate increases with increasing temperature, in contrast, one of self-made calcium removing reagent decreases with increasing temperature. A further study on the solubility of dihydrate calcium sulfate and self-made calcium removing reagent was carried out in practical electrolyte solution after the removal of copper and cadmium. The results showed that the solubility behaviors of dihydrate calcium sulfate and self-made calcium removing reagent are the same with those in simulated zinc sulfate solutions.Also, the influences of the quantity of calcium removing reagent added and stirring time on the concentration of Ca(Ⅱ) ion in the leaching solution after the removal of copper and cadmium were studied. The experimental results indicate that the "best" conditions for removal of calcium from the solution are:temperature80℃, pH5.2, amount of calcium removing reagent seed5.0g/L, stirring time1to2hours. Under the optimal condition, the concentration of calcium ion can be reduced to350ppm. Good results in removing calcium sulfate from electrolyte solution in zinc hydrometallurgical process could be achieved.Based on the above research, a new approach has been developed to remove the scaling of calcium sulfate in the zinc hydrometallurgy.更多还原