摘要
测定了KOHK3VO4H2O体系的溶解度,结合KOHK2CrO4H2O体系的溶解度变化规律,研究了KOHK2CrO4K3VO4H2O四元体系中蒸发结晶分离K2CrO4和冷却结晶分离K3VO4的方法.针对钒渣钾系亚熔盐分解获得的溶出液组成,研究了该体系中K2CrO4和K3VO4结晶分离工艺参数对分离效果的影响.结果表明,将溶出液蒸发至KOH浓度为630670g/L进行K2CrO4分离,K2CrO4结晶率达90%以上,晶体纯度达95%以上;将分离K2CrO4后的结晶母液继续蒸发至KOH浓度为800850g/L,从80℃到40℃自然降温,在搅拌速度200r/min、晶种添加量2%()的优化结晶条件下,K3VO4结晶率为60%以上,晶体纯度达90%以上.分离K2CrO4和K3VO4后的溶液返回钒渣亚熔盐分解反应过程循环使用.
The solubility of KOH-K3VO4-H20 system was determined. Based on the solubility variation of KOH-K3VO4-H2O and KOH-K2CrO4-H2O systems, the separation method of K2CrO4 and K3VO4 by evaporation crystallization and cooling crystallization respectively from KOH-K2CrO4-K3VO4-H2O system was established. Aiming at the digestion liquor obtained by the sub-molten salt decomposition reaction, the effects of process parameters on crystallization separation of K2CrO4 and K3VO4 was studied. The results showed that K2CrO4 was separated when the KOH concentration of digestion liquor was evaporated to 630~670 g/L. The crystallization rate of K2CrO4 was more than 80%, and its purity over 95%. The mother liquor was continuously evaporated, the optimal experimental conditions for the separation of K3VO4 were obtained： KOH concentration 800-850 g/L, temperature from 80 ℃ to 40℃ with natural cooling, stirring speed 200 r/min, seed load 2%（ω）. Under the conditions, the crystallization rate of K3VO4 was more than 60%, and its purity over 90%. The solution after the separation of K2CrO4 and K3VO4 was recycled for the sub-molten salt decomposition reaction.
出处
《过程工程学报》
CAS
CSCD
北大核心
2012年第3期402-408,共7页
The Chinese Journal of Process Engineering
基金
国家"十二五"科技支撑计划基金资助项目(编号:2012BAF03B01)
国家自然科学基金重大项目资助(编号:51090382)
国家高技术研究发展计划(863)基金资助项目(编号:2011AA060702)
关键词
铬酸钾
钒酸钾
氢氧化钾
亚熔盐
结晶分离
K2CrO4
K3VO4
KOH
sub-molten salt
crystallization separation
