复杂高硫渣中有价金属的分离工艺

Separation and enrichment of valuable elements from complex high-sulfur slag

采用煤油脱硫—氯盐浸出—分步水解法对复杂高硫渣中有价金属的分离进行研究。研究反应时间、反应温度、液固比等因素对实验过程的影响。结果表明:在反应温度为95℃,反应时间为0.5h,液固比分别为111时进行2次连续煤油脱硫实验,硫的脱除率为98%,脱硫渣中铋和锑富集,其含量约为复杂高硫渣的6倍。在硫酸质量浓度和氯化钠质量浓度均为150g/L,液固比为101,反应温度为65℃时,锑的浸出率为96%,铋的浸出率为98%。采用分步水解,在氯盐浸出液中控制pH=0.8水解沉锑;在沉锑后液中控制pH=1.5水解沉铋,锑和铋的沉淀率分别为85.6%和98%。在整个优化工艺条件下,锑的回收率为82%,铋的回收率为96%。

The separation and enrichment of valuable elements in the complex high-sulfur slag by oxygen-leaching from arsenic filter-cake were studied by the methods of re-desulfurization using kerosene,chloride-leaching,two-step hydrolysis.The effects of reaction time,temperature,mass ratio between the liquid and solid on leaching process were studied.The results show that the rate of desulfurization is 98%and the contents of Sb,Bi are enriched 6 times in the re-desulfurization slag when the temperature is 95℃,the reaction time is 0.5 h and mass ratio between the liquid and solid is 11 1 in the following two steps.In the chloride-leaching,the leaching rates of bismuth and antimony are 98%and 96%,respectively when the concentration of sulfuric acid and sodium chloride are 150 g/L respectively,mass ratio between the liquid and solid is 10 1,reaction time is 0.5 h and temperature is 65℃.In the two-step hydrolysis,SbOCl is obtained from the chloride leaching solution when pH value is 0.8,and BiOCl is obtained from the hydrolysis solution when pH value is 1.5.The deposition rates of bismuth and antimony are 85.6%and 98%,respectively.In the whole process of optimum conditions,the recoveries of bismuth and antimony reach 96%and 82%,respectively.