Ammonium vanadate/ammonia precipitation for vanadium production from a high vanadate to sodium ratio solution obtained via membrane electrolysis method
Ammonium vanadate/ammonia precipitation for vanadium production from a high vanadate to sodium ratio solution obtained via membrane electrolysis method
复制标题
DOI：
10.1016/j.jclepro.2020.121357
复制
发表时间：
2020-08
影响因子：
11.1
通讯作者：
Pan Bo;Biao Liu;Shaona Wang;Marco Wenzel;J. Weigand;M. Feng;H. Du;Yi Zhang
中科院分区：
文献类型：
--
作者：
Pan Bo;Biao Liu;Shaona Wang;Marco Wenzel;J. Weigand;M. Feng;H. Du;Yi Zhang
钒是一种重要的战略金属，在多个行业中得到了广泛的应用。然而，目前用于生产钒化合物的方法由于在钒沉淀操作期间钠盐、铵盐和酸的混合而产生显著量的高盐度含铵废水。为避免V2 O 5生产过程中产生的废水，提出了一种清洁、可循环利用的V2 O 5生产工艺。以NH 4VO 3和NH3·H2O为沉淀剂，从膜电解法得到的高钒钠摩尔比酸性溶液中沉淀钒酸盐（NH3）2·3V 2 O 5·H2O和（NH3）2·V2 O 5·H2O，避免了废水或固体废物的产生。煅烧后可得到高纯度的V2 O 5产品。采用ICP、XPS、SEM、XRD等技术研究了钒的沉淀过程，采用溶液电导法研究了钒的沉淀速率。详细考察了过量系数、溶液温度、溶液V/Na摩尔比和溶液pH等关键沉淀参数。结果表明，提高过量系数、溶液温度、溶液V/Na摩尔比以及降低溶液pH值，有利于获得纯度≥ 99.9%V2O5的钒产品。在V/Na摩尔比为2.58、过量系数为2、固溶温度为363 K时，获得了最佳的固溶工艺参数。使用两种沉淀剂获得的钒产品具有相似的纯度（大于99.9%），然而，由于水解反应的程度更高，与NH3·H2O沉淀法（38.76%）相比，NH 4VO 3沉淀法显示出更高的Na 2 Oyn −沉淀率（66.36%），表明第一种方法是上级的。在此基础上设计了一套完整的V2 O 5生产零排放工艺。本研究所提出的方法和获得的结果可为钒的清洁生产工艺设计提供依据。
Vanadium is an important strategic metal and has been widely applied in a multiple of industries. However, the current process for the production of vanadium compounds suffers from the generation of a significant amount of high salinity ammonium containing wastewater due to the mixing of sodium salts, ammonium salts, and acid during vanadium precipitation operation. In order to avoid the generation of wastewater at source, a clean and recyclable V2O5production process was proposed and investigated in this study. Using NH4VO3and NH3·H2O as precipitants, (NH3)2·3V2O5·H2O and (NH3)2·V2O5·H2O were obtained by precipitation of vanadate (VxOyn−) from a high vanadate to sodium (V/Na) molar ratio acidic solution obtained via membrane electrolysis method, avoiding the generation of wastewater or solid waste. After calcination, high purity V2O5product could be obtained. The vanadium precipitation process was investigated using ICP, XPS, SEM, XRD techniques, and the precipitation rate was investigated using solution conductivity method. Critical precipitation parameters such as excessive coefficient, solution temperature, solution V/Na molar ratio and solution pH were examined in detail. The results showed that increase the excessive coefficient, solution temperature and solution V/Na molar ratio, as well as reduce the solution pH would be beneficial for obtaining high purity vanadium products (≥99.9% V2O5). Optimum parameters were obtained at the V/Na molar ratio of 2.58, the excessive coefficient of 2, and the solution temperature of 363 K. The vanadium products obtained using both precipitants have a similar purity (more than 99.9%), however, due to a higher degree of hydrolysis reaction, the NH4VO3precipitation method showed a higher VxOyn−precipitation rate (66.36%) in comparison with the NH3·H2O precipitation method (38.76%), indicating that the first method was superior. Based on this, a complete process with zero waste emission for V2O5production was designed. The methods proposed and the results obtained from this study could provide fundamental information for the design of cleaner vanadium production process.