NaVO_(3)-H_(2)O体系碳酸氢铵/碳酸铵沉淀偏钒酸铵试验研究

Experimental study on precipitation of ammonium metavanadate in NaVO_(3)-H_(2)O system by ammonium bicarbonate and ammonium carbonate

针对钒渣钠法提钒得到的NaVO_(3)-H_(2)O溶液体系,利用碳酸氢铵/碳酸铵作为铵盐,考察了沉淀pH值、沉淀温度、结晶时间、加铵系数对偏钒酸铵结晶效果的影响。结果表明:在一定范围内提高溶液的pH值(9.1~9.5),可以改善偏钒酸铵的结晶率;在温度15~27℃、结晶时间>3 h、加铵系数不小于2.9条件下,可实现偏钒酸铵结晶率>85%,经煅烧获得的五氧化二钒纯度>99.3%,满足YB/T 5304—2017质量标准要求。

For the NaVO_(3)-H_(2)O solution system obtained by extracting vanadium from vanadium slag by sodium method,the effects of precipitation pH value,precipitation temperature,crystallization time,ammonium addition coefficient on the crystallization of ammonium metavanadate were investigated using ammonium bicarbonate and ammonium carbonate as ammonium salt.The results show that the crystallization rate of ammonium metavanadate can be improved by increasing the pH value of the solution(9.1–9.5)in a certain range.Under the conditions of temperature 15–27℃,crystallization time>3 h and ammonium addition coefficient no less than 2.9,the crystallization rate of ammonium metavanadate is higher than 85%,and the purity of vanadium pentoxide obtained by calcination ammonium metavanadate is higher than 99.3%,meeting the requirements of YB/T 5304—2017 quality standard.