石煤氧化焙烧-碱浸提钒工艺

摘要

研究NaOH与纯碱添加量比例对氧化焙烧石煤中钒浸出率的影响。在最佳比例的浸出剂下，研究浸出温度、时间和液固比对钒浸出的影响以及浸出液循环利用实验。结果表明：在相对石煤质量12%NaOH 和4%纯碱的浸出剂下，钒浸出率达到88.67%，比单独使用12%的NaOH做浸出剂下钒的浸出率提高10%左右。在最佳质量分数的浸出剂下，最佳工艺条件为：浸出液NaOH浓度为1.0 mol/L，纯碱浓度为0.13 mol/L，浸出温度为95℃，时间为3 h，液固比为3：1。浸出液经固液分离后循环使用，第二次添加原有浸出剂用量的1/4，第三次添加原有浸出剂用量的1/2后，平均钒浸出率达83.40%，不仅降低了浸出剂用量，同时也提高了水资源的利用率。%The effect of the addition amount of NaOH and Na2CO3 on the leaching rate of vanadium from roasted stone coal was studied. With the optimal condition of leaching agent, the effects of leaching time, temperature and liquid to solid ratio on vanadium leaching rate and the leaching solution recycle experiment were studied. The results show that the leaching rate of vanadium is 88.67%under the condition of 12%NaOH and 4%Na2CO3 compared with the mass of stone coal, which is almost 10% higher than the leaching rate with NaOH 12% only in reaction system. The optimal technological conditions are that the NaOH concentration is 1.0 mol/L, the Na2CO3 concentration is 0.13 mol/L, the leaching temperature is 95℃, the leaching time is 3 h and the liquid to solid ratio is 3:1. The leaching agent was recycled to extract vanadium after solid-liquid separation. The average leaching rate is 83.40%when 1/4 of original leaching agent is added at the second time and 1/2 is added at the third time. The amount of the leaching agent is reduced and water efficiency is enhanced at the same time.