锂云母矿石提锂浸取液体系中除铝的研究  

Aluminum Recovery in Leaching Solution of Lepidolite after Lithium Extraction

作　　者：旷戈[1] 郭慧[1] 刘善军[1] 罗文斌[1] 尚亚伟 

机构地区：[1]福州大学化学化工学院,福建福州350108

出　　处：《稀有金属》2014年第1期102-107,共6页Chinese Journal of Rare Metals

基　　金：国家科技部十二五国家科技支撑计划(2012BAB10B02)资助项目

摘　　要：锂云母矿物提锂浸取液中含有较高浓度的铝,如何有效去除或者回收铝成为降低综合提锂成本的关键。在综合考察碱法、酸法及溶剂萃取法等传统回收铝的方法的优点和不足之处的基础上,提出了一种更为有效的除铝方法,即铝与浸取液中K等其他组分形成钾明矾等含附加值的矾,在去除铝的同时又能联产其他化工产品,从而降低矿物提锂的综合成本。本研究采用等温溶解平衡法对浸取液特征体系中两个三元子体系Li2SO4-Al2(SO4)3-H2O和K2SO4-Al2(SO4)3-H2O在低温下(5℃)的稳定相平衡关系进行了初步研究,可以为浸取液成矾除铝提供基础数据及理论指导。依据溶解度数据绘制出Li2SO4-Al2(SO4)3-H2O和K2SO4-Al2(SO4)3-H2O的稳定平衡相图,平衡液相所对应的固相由X射线粉末衍射仪(XRD)确定,并划分出相应的结晶区。由相图可以看出,Li2SO4和Al2(SO4)3并未形成复盐,而K2SO4则与Al2(SO4)3可在较大浓度范围内形成钾明矾KAl(SO4)2·12H2O。研究表明,Li+,Al3+不易成矾,而K+和Al3+易形成钾明矾。生产实践中,可以通过调节浸取液中Li+、K+和Al3+的组分浓度,使其浓度范围控制在钾明矾的成矾结晶区,最终使高浓度的铝通过成矾结晶的形式得到综合回收利用。同时又能使Li和K组分得到初步分离,进而降低综合提锂成本,提高矿物提锂工艺的生产效益。Since the leaching solution of lepidolite contained a great amount of aluminum after lithium extraction, how to remove or recover effectively would definitely affect the cost for lithium extraction. The comprehensive analysis was made on the merits and shortcomings of the traditional methods ： alkali, acid and solvent extraction methods. Then a more effective way was proposed ： recovered a- luminum by alums formation with K ~ or other components contained in the leaching solution. The cost for lithium extraction would he decreased by producing value added co-products such as potassium alum. The Li2SO4-Al2 （SO4） 3-H2O and K2SO4-Al2 （SO4） 3 -H2O ternary systems were the subsystem of the featured system of the leaching solution. The phase equilibria in the Li2SO4-Al2 （SQ） 3-H2O and K2SO4-Al2 （SO4）3-H2O ternary systems at 5 ℃were investigated with isothermal equilibrium method. The phase equilibria investigation could provide fundamental data and instruction for lithium extraction, which was important for alum formation to recover aluminum. The solid phase was determined by X-ray diffraction （XRD） analysis. Based on the solubility data, the phase diagrams were plotted. The crystallized fields also were determined. The phase diagrams showed that K2SO4 and Al2 （SQ）3 could form potassium alum （KAI（ SO4） 2. 12H2O） in a large range of concentration, while it seemed that Li2SO4 and Al2 （SO4） 3 could not form double salts. The investigation indicated that Li ~ and Al^3＋ could not form alum, but K ＋ and Al3 ＋ could form potassium alum easily. Therefore, the aluminum could be recovered by regulating K^＋ , Li^＋ and Al3^＋ concentration to form alums. Thus, the aluminum was recovered as high value co-products, and lithium and potassium could be separated preliminarily. The alum formation method could decrease costs and enlarge profit for lithium extraction, which had significant practical meaning for lithium extraction.

关 键 词：锂云母 提锂 除铝 成矾 相平衡 

分 类 号：TQ115[化学工程—无机化工] TF11[冶金工程—冶金物理化学]