含锂矿石酸浸提锂浸出液中铝的脱除工艺研究

Removal of Aluminum From an Acid Leachate Containing Lithium

一种含锂的萤石浮选尾矿的硫酸浸出液中含有较高浓度的铝,铝的脱除是锂回收工艺中的重要步骤.该文采用两步脱铝工艺,第一步为钾明矾法,第二步为苯甲酸盐法,取得了较好的脱铝效果,脱铝过程锂的损失低,苯甲酸盐可以再生.在第一步钾明矾法试验中,考查了静置沉淀时间对铝脱除效率的影响;在第二步苯甲酸盐法试验中,考察了pH、温度、苯甲酸盐用量、反应时间对铝脱除效果的影响.试验结果表明,在pH为2.5,温度为室温,苯甲酸钠用量为1.2倍理论量,反应时间为25 min的条件下,铝的脱除率在95%以上,锂的损失率低于3%.

In a sulfuric acid leachate from a fluorite flotation tailings containing lithium,aluminum removal is an important factor for lithium recovery and quality.In this paper,the two-steps technique of aluminum removal was developed,including potassium alum method and benzoate method,and aluminum could be removed effectively by this technique.The loss of lithium in the process of aluminum removal is low,benzoate can be regenerated.In the first step of potassium alum test,the effect of static precipitation time on aluminum removal efficiency was investigated.In the second step of benzoate method,the effects of pH,temperature,benzoate dosage and reaction time on aluminum removal were investigated.The results showed that under the condition of pH=2.5,room temperature,sodium benzoate dosage of 1.2 times theoretical amount and reaction time of 25 min,the removal efficiency of aluminum was more than 95%,and the loss of lithium was less than 3%.