钒渣钙化焙烧熟料酸浸工艺温度控制

Temperature Control of Acid Leaching Process for Calcified Clinker of Vanadium Slag

钒渣钙化焙烧熟料采用硫酸浸出工艺得到含钒浸出液,在工业生产中发现其浸出过程温度升高易引起钒水解沉淀,导致钒收率降低。针对钙化熟料浸出过程温度控制问题,研究了浸出过程硫酸浓度、硫酸加入量、固液比和浸出剂初始温度对浸出的影响。结果表明:硫酸浓度、固液比和浸出剂初始温度对钙化熟料浸出料浆温度有明显影响,优选浸出pH为2.7~2.9,硫酸浓度≤38%,固液比0.3~0.4,浸出剂初始温度25~35℃,可控制浸出料浆温度满足工艺要求,并获得较高的钒浸出率。通过浸出工业生产验证,浸出温度平均降低了13.09℃,钒浸出率平均提高了3.45个百分点,应用效果显著。

The calcified clinker of vanadium slag is usually leached by sulfuric acid to obtain V-containing solution. During the industrial process of acid leaching, the leaching temperature increases abnormally and vanadium in the solution will be precipitated to decrease the recovery rate. In this paper, the effects of sulfuric acid concentration, sulfuric acid addition, solid-liquid ratio and the initial temperature of leaching agent on the leaching process were investigated. The results show that the sulfuric acid concentration, solid-liquid ratio and initial temperature of leaching agent influence the leaching temperature obviously. The leaching slurry temperature can be controlled to satisfy the process requirements with a higher vanadium leaching rate, at optimum conditions for leaching pH of 2.7~2.9,concentration of sulfuric acid ≤38%,solid-liquid ratio of 0.3~0.4 and leaching agent initial temperature of 25~35 ℃. Verified by industrial leaching production, the leaching temperature can be reduced by an average of 13.09 ℃,with the leaching rate of vanadium increasing by 3.45 percentage points.