K^(+)对拜耳法溶出过程中含钾铝土矿反应行为的影响  

Effects of K^(+) on Reaction Behaviors of Potassium-bearing Bauxite during Bayer Digestion Process

作　　者：武国宝 WU Guo-bao(Zhengzhou Nonferrous Metals Research Institute Co.,Ltd.,CHALCO,Zhengzhou 450041,China)

机构地区：[1]中铝郑州有色金属研究院有限公司,郑州450041

出　　处：《有色金属（冶炼部分）》2021年第7期16-20,41,共6页Nonferrous Metals（Extractive Metallurgy)

基　　金：中国铝业股份有限公司科技专项(ZB2020001007)。

摘　　要：用不同K^(+)浓度的铝酸钠溶液进行了含钾铝土矿的拜耳法溶出试验和溶液脱硅试验。结果表明,在30.19~301.94g/L内,溶液中K^(+)浓度的变化对氧化铝溶出率和溶出赤泥N/S的影响较小;随着溶液中K^(+)浓度的升高,铝土矿中K2O的表观溶出率显著降低,但无法完全阻止K元素在溶出过程中进入溶液。在溶液中K^(+)浓度≤155.28g/L条件下,K^(^(+))取代Na^(+)进入钠硅渣晶格的难度大,工厂溶液中K^(+)的平衡浓度预计会远高于当前的水平。应用含钾铝土矿生产的企业必须采取除钾工艺措施才能有效控制生产系统中钾含量的升高。Experiments on Bayer digestion of potassium-bearing bauxite and solution desilication with different concentration of K^(+)in caustic sodium aluminate solution were carried out.The results show that,in range of 30.19~301.94 g/L,variation of concentration of K^(+)in caustic sodium aluminate liquor has less effect on extraction efficiency of alumina and N/S of red mud.Entering of K element into liquor cannot be prevented entirely during Bayer digestion process,even apparent extraction efficiency of K2O contained in bauxite can be reduced remarkably with increasing of K^(+)concentration in caustic sodium aluminate liquor.It is difficult for K^(+)to replace Na^(+)and enter into crystal lattice of sodium aluminosilicate hydrate as K^(+)concentration in solution is not higher than 155.28 g/L,and equilibrium concentration of K^(+)in plant solution would be much higher than current level.Technological measures for potassium removal should be taken to control increasing concentration of K^(+)effectively in plant production system.

关 键 词：K^(+) 含钾铝土矿 拜耳法 溶出 反应行为 

分 类 号：TF821[冶金工程—有色金属冶金]