含铬、钴废催化剂的回收研究

论文编号:HG240  论文字数:16816,页数:25

摘 要：本文根据含钴、铬废催化剂的特点，比较各种分离方法，提出了较为经济合理的焙烧、酸溶解和萃取分离的工艺流程。与单化学沉淀方法比，本工艺流程具有铬、钴的回收率高，工艺路线简单，可以节约成本的特点。
 废催化剂焙烧、溶解过程，通过单因素实验得到较佳的工艺条件如下：焙烧温度400℃，纯碱与废催化剂的质量比为1.0：1，粒度为60目，焙烧时间为4h，溶解液为40%硫酸，液固比为10.0：1，溶解温度为120℃，溶解时间1h，在此条件下，废催化剂的溶解率为99%。
 废催化剂萃取分离过程，通过单因素实验得到较佳的工艺条件如下：萃取剂的含量为30%，皂化率为60%，溶液的pH为2.0，溶液温度为室温，平衡时间为3min，钴萃取率达到99%以上，铬的萃取率在5%以下。
　　废催化剂经过焙烧、溶解、萃取分离后，可以得到产品草酸钴以及氢氧化铬。
关键词：废催化剂；溶解率；P507萃取；钴回收

Abstract： According to the characteristic of spent catalyst which contains cobalt and chromium, a economical and reasonable technical process of roasting, the acid dissolution and the extraction separation has been proposed comparing with many separation methods. The characteristic of this technical process is higher recovery rate of cobalt and chromium, simpler technological route and lower cost，compared with the single chemistry precipitation.
 In the process of roasting and dissolution, better technological conditions can be got as follows by single factor experiment: roasting temperature is 400°C, the reaction time is 4 hours, the mass ratio of spent catalyst to the sodium carbonate is 1：1, spent catalyst padding granularity is 60 items, the fluid-to-solid ratio is 10：1, the solution temperature is 120 ° C，the dissolution time is 1h，40% sulfuric acid as the solvent substance. Based on the above conditions, the dissolution ratio is more than 99%.
 In the process of extraction and separation, better technological conditions can be got as follows by single factor experiment: the content of extracting agent is 30%, the saponification ratio is 60%, the solution pH is 2.0, the solution’s temperature is room temperature, the equilibrium time is 3min, the cobalt extraction ratio is up to 99%, the chromium extraction ratio is less than 5%.
 After the process of roasting, dissolution, and the extraction separation, the products cobalt oxalate and the chromic hydroxide from the spent catalyst can be prepared.
Keywords： Spent catalyst; Dissolution ratio; P507 extraction; Chromium recovery