硒酸泥制备粗硒新工艺

摘要

Crude selenium was prepared from selenium acid mud using a new technology of kerosene desulphurization, oxidization-leaching and reduction-extraction of selenium. The results show that kerosene can effectively remove sulfur from selenium acid mud when the temperature is controlled above 95℃, and the rate of desulphurization is larger than 97%. Accordingly, the optimum oxidization-leaching conditions are determined as follows: temperature 80℃, leaching time 2 h and ratio of liquid to solid of 5:1, H2SO4 concentration 300 g/L. After oxidization-leaching under optimum conditions, the leaching rate of selenium can reach above 97%. The optimum conditions of selenium deposition experiments are obtained as m(H2NCSNH2)=0.60 g, m(Na2SO3)=7 g, the acidity of 150 g/L, temperature of 23 V, aging time of 10 h. In the whole process under optimum conditions, the rate of desulphurization is larger than 97%, the recovery of selenium is above 97%, and the ultimate selenium content in the crude selenium is more than 92%, respectively.%研究采用煤油脱硫-氧化浸出—还原沉硒法处理硒酸泥制备粗硒的新工艺.研究结果表明:当温度控制在95℃以上时,煤油可有效去除硒酸泥中的单质硫,硫的脱除率大于97％;当浸出温度为80℃、浸出时间为2h、液固比为5∶1和H2SO4质量浓度为300g/L时进行NaClO3氧化浸硒实验,硒的浸出率为97.76％;采用硫脲-Na2SO3还原沉硒,优化条件为:硫脲加入量0.60 g,Na2SO3加入量7 g,酸度150 g/L,陈化时间10h.在整个优化工艺条件下,硫的脱除率大于97％,硒的回收率大于97％,粗硒的品位大于92％.