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采用溶剂萃取法从含钒钨酸钠溶液中选择性萃取分离V。考察了萃取体系组成、料液初始pH值、萃取相比、振荡时间、温度等因素对萃取效果的影响,并确定了萃取级数和反萃体系,考察了萃取剂循环使用效果。实验结果表明,采用组成(体积分数)为20%N263+40%仲辛醇+40%磺化煤油的有机相体系,对初始pH值为8.70、WO3浓度为66.21g/L、V2O5浓度为11.46g/L的料液进行萃取分离V,在相比O/A为1/2.5及室温条件下,经过6级逆流萃取,V2O5萃取率达到99.90%以上,WO3的共萃率仅8.00%左右,萃余液中V2O5浓度可降至10 mg/L以下;负载有机相用1.5mol/L NaCl+2mol/L NaOH溶液反萃,在相比O/A为3/1及室温条件下,V2O5单级反萃率可达95.24%,WO3单级反萃率为100%。萃取剂在循环使用过程中对钒钨的萃取效果基本不变。
V is selectively extracted from vanadium-containing sodium tungstate solution by solvent extraction. The effects of extraction system composition, initial pH value of feed solution, extraction time, temperature and other factors on the extraction efficiency were investigated. The extraction series and stripping system were also investigated. The experimental results showed that the optimum conditions were as follows: the initial pH was 8.70, the concentration of WO3 was 66.21g / L, the concentration of V2O5 was 11.46 g / L, the V2O5 extraction rate was over 99.90% after 6 stages countercurrent extraction at O / A ratio of 1 / 2.5 and room temperature, and the WO3 co-extraction rate was only about 8.00% The concentration of V2O5 in the raffinate can be reduced to less than 10 mg / L. The loaded organic phase is stripped with 1.5 mol / L NaCl + 2 mol / L NaOH solution. When the O / A ratio is 3/1 and room temperature, Level stripping rate of up to 95.24%, WO3 single-stage stripping rate of 100%. Extractant in the recycling process of vanadium tungsten extraction effect basically unchanged.