硫酸锌电解液净化工艺和反应器的研究
文献类型：学位论文
| 作者 | 赵光明 |
| 学位类别 | 硕士 |
| 答辩日期 | 2010-05-21 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 张广积 ; 杨超 |
| 关键词 | 硫酸锌溶液 除钴 深度净化 铜离子 反应器 |
| 其他题名 | Studies on the process and reactor for zinc fulfate solution purification |
| 学位专业 | 化学工程 |
| 中文摘要 | 湿法炼锌工艺的硫酸锌电解液的净化除钴离子（Co2+）一直是工业难题。如果能够将钴离子浓度（[Co2+]）深度净化到0.1 mg/L，则其它杂质都能达到相应的深度净化水平。目前除钴工序存在很多问题，如锌粉消耗量多（200倍钴当量）、锌粉利用率低（仅10%左右）、净化渣难处理、能耗高等。且因为除钴不完全，导致后续电解积锌操作被迫提前中断、电流效率低和电积锌质量差，使生成的电积锌板厚度低（低于3 mm），只能采用人工剥锌。随着湿法炼锌工业的发展，国外的先进工艺已采用机械化剥锌，可以显著降低劳动强度和提高劳动生产率。因而，为了提高我国的湿法炼锌生产效率，必须设法将Co2+净化达到深度净化的水平。目前除钴主要采用的方法是锑盐除钴法。影响除钴效果的影响因素有很多，主要有：温度、锌粉用量及组成、初始铜离子浓度（[Cu2+]0）、氧气、搅拌等。本文首先通过单因素法研究了这几个因素对除钴的影响，再通过正交实验重点考察了锑离子、[Cu2+]0、温度和搅拌转速，确定了以Cu2+为深度净化除钴研究核心。本文对铜离子（Cu2+）在除钴中的影响进行了深入研究，考察了[Co2+]达到深度净化浓度的时间、低于深度净化浓度的持续时间以及达到深度净化要求的[Cu2+]0等因素。综合衡量除钴效果，得到最优的实验条件：初始钴离子浓度（[Co2+]0）15 mg/L时，钴锑质量比（Co/Sb）=2:1，[Cu2+]0 200 mg/L，达到深度净化浓度的时间和保持该浓度的时间分别是25和70 min；[Co2+]0 为7.5 mg/L时，Co/Sb=2:1，[Cu2+]0 100 mg/L，达到深度净化浓度的时间和保持该浓度的时间分别是40和55 min。最后对转速和反应器结构影响除钴的效果进行了研究，将500 mL反应体积得到的实验结果在4 L的反应器中进行验证，并利用SEM和能谱分析净化渣表面形态和组成，表明放大后仍可以取得较好除钴效果，转速对除钴的影响不大，但是高转速有利于返溶，推断返溶的原因可能是沉积的碱式钴盐溶解。同时采用1/2挡板有利于除钴的高效进行和降低能耗。 |
| 英文摘要 | In hydrometallurgical zinc production, cobalt, among all metallic impurities in the zinc electrolyte, is the most difficult one to be removed and has the most detrimental effect in electrowinning of metal zinc. There are many problems in the removal of cobalt ion ([Co2+]) in zinc sulfate solution, such as high consumption of zinc powder (200 times the stoichiometric amount of cobalt to be removed), low utilization ratio of zinc (only about 10%), hard disposal of purification residue, high-energy consumption and so on. Because of residual cobalt, the time of electrowinning operation is shorter than scheduled, with low current efficiency and poor quality of electrowinned zinc, which leads to the thickness of zinc sheet less than 3 mm and the hand-scalping process of zinc has to be recurred to. Along with the development of zinc industry, mechanized zinc scalping has been adopted in foreign advanced zinc hydrometallurgical factories and can decrease the labor intensity and increase the productivity remarkably. To improve the production efficiency of zinc hydrometallurgy in China, the removal of cobalt should be upgraded to the deep purification level. Currently, the addition of antimony-activator is the main method for removal of cobalt. There are many influencing factors in the process, such as temperature, amount and component of zinc powder, initial concentration of copper ion ([Cu2+]0), oxygen, agitation speed. In the present work, the effects of those factors were investigated by single factor analysis method firstly, and then the antimony ion, [Cu2+]0, temperature and agitation speed were studied by orthogonal tests. [Cu2+]0 was confirmed as the most important factor in the process of deep removal of cobalt from zinc sulfate solution. The effect of copper ions on deep removal of cobalt from zinc sulfate solution was analyzed comprehensively by several criteria, including tr the time when [Co2+] cobalt concentration being lowered to 0.1 mg/L, td the duration when [Co2+] was below 0.1 mg/L and [Cu2+]0 the initial concentration of copper guaranteeing the deep removal of cobalt. The best results were tr=25 min, td=70 min under the optimal conditions of additing [Cu2+]0 200 mg/L, mass ratio of Co and Sb (Co/Sb) at 2:1 for solution of [Co2+]0=15 mg/L, and tr=25 min, td=70 min when additing [Cu2+]0 100 mg/L, Co/Sb=2:1 for [Co2+]0 of 7.5 mg/L. The effects of the agitation speed and the reactor configuration were studied. The above optimal conditions were validated in a 4 L stirred reactor, and the purification process residue was examined by SEM and energy spectrum to analyse the surface topography and contents. It was indicated that the agitation speed had little effect on cobalt removal, and even promoted redissolution of precipitated cobalt, which is probably due to the dissolution of basic cobalt salt. [Co2+] reached 0.1 mg/L in the 4 L reactor. Wall baffles with the 1/2 height of solution level was good for efficient cobalt removal and energy consumption. |
| 语种 | 中文 |
| 公开日期 | 2013-09-22 |
| 页码 | 75 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1637]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 赵光明. 硫酸锌电解液净化工艺和反应器的研究[D]. 中国科学院研究生院. 2010. |
入库方式： OAI收割
来源：过程工程研究所
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