钼酸铵溶液化学沉淀法和离子交换法除钒研究

Removal of Vanadium from Ammonium Molybdate Solution by Chemical Precipitation and Ion Exchange

对采用化学沉淀法、运用A,B两种强碱性阴离子树脂交换法,从钼酸铵溶液中分离除钒的工艺条件进行了研究。研究结果表明:控制溶液pH值在8～9时,钒主要以VO 3-状态存在,沉钒效率高,偏钒酸铵沉淀纯度也高,达98.5%以上。A树脂能够深度分离钼酸铵溶液中的钒,最佳工艺条件是:控制料液pH值在7.28左右和降低Cl-浓度。Cl-与A树脂有较强的亲和力,其浓度的增加会显著降低A树脂对钒的吸附容量。在溶液pH值为7.28,几乎不含Cl-的条件下,A树脂饱和吸钒容量达到了21.73 g·L-1,此工艺可控制钼酸铵溶液中钒浓度在0.02 g·L-1以下。A树脂最高解析回收率达到98.68%,确保了钼钒深度分离后钒的回收利用效果。B树脂能够有效回收A树脂解析液中的钒和钼,其吸钒容量达到26.22 g·L-1,吸钼容量达到了71.06 g·L-1。B树脂为A树脂的优化树脂,其饱和吸附容量大于A树脂的饱和吸附容量。

The process conditions of vanadium removal from ammonium molybdate solution by chemical precipitation and ion exchange using A and B two kinds of alkaline anion resins were studied.It was found that controlling the pH value between 8 and 9,vanadium existed mainly as VO-3,the efficiency of NH4VO3′s precipitating was significant,and purity of NH4VO3 was high as above 98.5%.Resin A could separate vanadium from ammonium molybdate greatly,the best technological conditions were pH value of about 7.28 and reducing the concentration of Cl-.Cl-had strong appetency with resin A,and the increase of Cl-concentration notably reduced adsorption capacity of resin A.Resin A′s adsorption capacity of vanadium reached 21.73 g · L-1 under the conditions of 7.27 pH value and without Cl-.This technology could control the concentration of vanadium under 0.02 g · L-1 in ammonium molybdate solution.The highest stripping recovery rate of resin A was 98.68%,this ensured the good recovery result after the separation of ammonium and vanadium.Resin B could effectively recycle vanadium and ammonium from stripping solution of resin A,its adsorption capacity of vanadium reached 26.22 g · L-1,and its adsorption capacity of ammonium reached 71.06 g · L-1.Resin B was optimization of resin A,and it had larger adsorption capacity than resin A.