回收及浸出剂的再生
(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 研究了从亚氨基二乙酸浸出低品位氧化锌矿所得的Zn2+-Ida2−-H2O溶液中锌的回收和浸出剂的再生。首先加入CaO调节溶液pH使锌以粗氧化锌形式加以回收，然后通入CO2气体使沉锌过程中所积累的大量钙离子以CaCO3形式脱除，同时实现浸出剂亚氨基二乙酸的再生。确定沉锌工艺条件如下：沉锌温度85 ℃、终点pH值10、陈化时间60 min；沉钙工艺条件如下：沉钙温度70 ℃、终点pH值8、CO2流量0.2 L/min。结果表明：浸出液按上述条件进行沉锌—沉钙—再浸出处理后，沉锌率为93.37%，沉钙率为97.88%，锌浸出率为78%；所得粗氧化锌含锌56.91%、铅3.40%，碳酸钙纯度大于97%。
关键字: 氧化锌矿；亚氨基二乙酸；沉淀；浸出剂再生
Zn2+-Ida2−-H2O system
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The recovery of Zn and the regeneration of lixiviant from the Zn2+-Ida2−-H2O solution which is obtained by low grade zinc oxide leached with iminodiacetic acid were investigated. Zn was precipitated as ZnO by adjusting the pH value of the leaching solution with CaO, and the lixiviant was regenerated subsequently when the accumulated Ca was removed as CaCO3 by adding CO2. The optimal conditions for Zn precipitation are determined as follows: the Zn precipitation temperature of 85 ℃, final pH of 10 and aging time of 60 min. And the optimal conditions for Ca precipitation are as follows: the Ca precipitation temperature of 70 ℃, final pH of 8 and flow rate of CO2 gas of 0.2 L/min. The results show that when leaching liquor is treated under above optimal conditions, the precipitation of Zn is 93.37%, the precipitation of Ca is 97.88% and the leaching recovery of Zn is 78%. ZnO obtained from Zn precipitation process contains 56.91% Zn and 3.40% Pb, while CaCO3 obtained from Ca precipitation process has a purity more than 97%.
Key words: zinc oxide ore; iminodiacetic acid; precipitation; lixiviant reclamation
