铝酸钠溶液中钒酸盐的析出行为研究

Crystallization Behavior of Vanadate in Sodium Aluminate Solution

以氧化铝生产流程中氢氧化铝的洗涤液为原料,研究了苛性碱浓度、反应温度及反应时间对溶液中钒酸盐析出情况的影响。结果表明,钒酸盐的析出率随苛性碱浓度的升高和反应时间的延长而增大,随反应温度的升高而减小。当铝酸钠溶液的苛性碱浓度为200g/L、反应温度为30℃、反应时间为72h时,溶液中的钒元素可减少60%以上。结晶析出的钒酸盐主要为钒酸钠和偏钒酸钠,其晶体结构为八面体。

Influence of caustic alkali concentration,reaction temperature and reaction time on precipitation of vanadate in aluminum hydroxide washing solution was studied applying washing liquid of aluminum hydroxide during alumina production as raw material.The results show that precipitation rate of vanadate rises with increase of caustic concentration and reaction time,but drops with increase of reaction temperature.When reaction temperature is 30℃,concentration of caustic soda in sodium aluminate solution is 200 g/L,and reaction time is 72 h,vanadium content in solution can be reduced by more than 60%.XRD and SEM analysis shows that vanadate precipitated in form of sodium vanadate and sodium metavanadate,and its crystal structure is octahedron.