用偏钒酸铵制备偏钒酸钠工艺研究

对以偏钒酸铵为原料制取偏钒酸钠的工艺进行了研究。提出了以乙醇作为溶析剂，对偏钒酸钠溶液进行溶析结晶，并获得了良好效果。考察了制备过程中的主要影响因素，并确定了最佳工艺条件：碱溶pH=9~10、脱氨温度为90 ℃、浓缩终点溶液pH=7.5~8.0、浓缩终点总钒质量浓度为160 g/L、溶析剂与溶液体积比为1∶1、结晶时间为60 min。在最佳工艺条件下，通过碱溶除杂、脱氨浓缩、溶析结晶等工艺过程，制备出高纯度的偏钒酸钠，产品纯度达到99.5%以上。该方法工艺简单，对于生产高纯度的偏钒酸钠产品具有重要的指导作用。

Study on preparation technology of sodium metavanadate with ammonium metavanadate

The preparation technology of sodium metavanadate was studied with ammonium metavanadate as raw material. Solventing-out crystallization was applied in sodium metavanadate solution by using ethanol as eluent and good results were obtained.The main influence factors of process were investigated，and the optimum process conditions were determined：alkali dissolving pH was 9~10，ammonium removal temperature was 90 ℃，terminal pH of concentrate was 7.5~8.0，mass concentration of total vanadium for concentrated terminal point was 160 g/L，volume ratio of solventing-out agent to solution was 1∶1，and crystallization period was 60 min.The results showed that the purity of prepared sodium metavanadate can reach more than 99.5% under the optimum process conditions，through some processes，such as alkali dissolving and impurity removal，ammonium removal and concentration，and solventing-out crystallization.The results showed that the process was simple and had an important guiding role on the preparing high-purity sodium metavanadate.