制备高品质多钒酸铵工艺参数优化与研究

Optimization and Study on process parameters for preparation of high quality ammonium polyvanadate

工业生产航空航天用五氧化二钒、高纯五氧化二钒、工业级五氧化二钒以及三氧化二钒等产品需要低杂质、大颗粒、低水份的多钒酸铵或偏钒酸铵,目前生产以上产品使用最多的是多钒酸铵。而从含钒溶液中提取与回收钒的方法有多种,目前最常用和最成熟的方法是酸性铵盐沉淀法,而影响酸性铵盐沉钒的因素主要有:钒液质量、沉淀液的pH值、杂质含量、悬浮物、铵盐的加入量、沉钒时间、沉淀过程中的酸度、温度等。本研究通过实验以及生产实践的方法对以上影响因素进行了工艺参数优化,通过铝法除杂参数的优化可以得出,除杂温度不高于80℃、搅拌时间6~9分钟、pH值8~9,除杂系数0.8~0.95。钒液浓度在28g/l左右时采用一次加酸沉淀,进液后直接加铵盐和硫酸(进液温度42℃左右),沉淀酸度控制在1.9~2.4之间。硫酸铵沉钒反应温度大于95℃,氯铵沉钒温度大于90℃,加铵系数调整为0.8左右。通过工艺参数的优化和研究,多钒酸铵的品质得到提升,同时降低了产线辅料以及能源成本。

Ammonium polyvanadate or ammonium metavanadate with low impurity,large particle and low water content is needed for the industrial production of vanadium pentoxide,high purity vanadium pentoxide,industrial grade vanadium pentoxide and vanadium trioxide for aerospace.At present,ammonium polyvanadate is the most used product in the production of the above products.There are many methods to extract and recover vanadium from vanadium containing solution.At present,the most commonly used and mature method is acidic ammonium salt precipitation.The main factors affecting the precipitation of vanadium by acidic ammonium salt are:the quality of vanadium solution,pH value of precipitation solution,impurity content,suspended solids,amount of ammonium salt,precipitation time,acidity and temperature in the precipitation process.In this study,the process parameters of the above factors were optimized through experiments and production practice.Through the optimization of the parameters of aluminum method,it can be concluded that the impurity removal temperature is not higher than 80℃,the stirring time is 6~9 minutes,the pH value is 8~9,and the impurity removal coefficient is 0.8~0.95.When the concentration of vanadium solution is about 28g/L,acid precipitation is used once.Ammonium salt and sulfuric acid are directly added after the solution is fed into the solution(the feed temperature is about 42℃),and the acidity of precipitation is controlled between 1.9 and 2.4.The reaction temperature of vanadium precipitation with ammonium sulfate is higher than 95℃,the temperature of vanadium precipitation with ammonium chloride is higher than 90℃,and the ammonium addition coefficient is adjusted to about 0.8.Through the optimization and research of process parameters,the quality of ammonium polyvanadate was improved,and the production line auxiliary materials and energy costs were reduced.