回收及浸出劑的再生
(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究了從亞氨基二乙酸浸出低品位氧化鋅礦所得的Zn2+-Ida2−-H2O溶液中鋅的回收和浸出劑的再生。首先加入CaO調(diào)節(jié)溶液pH使鋅以粗氧化鋅形式加以回收，然后通入CO2氣體使沉鋅過程中所積累的大量鈣離子以CaCO3形式脫除，同時實現(xiàn)浸出劑亞氨基二乙酸的再生。確定沉鋅工藝條件如下：沉鋅溫度85 ℃、終點pH值10、陳化時間60 min；沉鈣工藝條件如下：沉鈣溫度70 ℃、終點pH值8、CO2流量0.2 L/min。結(jié)果表明：浸出液按上述條件進行沉鋅—沉鈣—再浸出處理后，沉鋅率為93.37%，沉鈣率為97.88%，鋅浸出率為78%；所得粗氧化鋅含鋅56.91%、鉛3.40%，碳酸鈣純度大于97%。
關(guān)鍵字: 氧化鋅礦；亞氨基二乙酸；沉淀；浸出劑再生
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
