Novel method for preparing molybdic acid

The invention provides a novel method for preparing molybdic acid, which comprises the following steps: by taking crude sodium molybdate as a raw material, deeply removing impurities in molybdate through a precipitation method and an ion exchange method, forming a molybdic acid solution from the obtained pure sodium molybdate solution through a bipolar membrane electrolysis system, and adding a crystallization aid or heating and crystallizing to prepare a high-purity molybdic acid product. According to the method, impurities in molybdenum can be deeply removed, inorganic acid does not need to be consumed, the method is environment-friendly, a NaOH byproduct generated in the production process can be recycled in the process, the recovery rate is high, and the production cost is low; the quality of the obtained molybdic acid product meets the raw material standard of the catalyst industry. 本发明提供了一种制备钼酸的新方法，该方法以粗钼酸钠为原料，通过沉淀法、离子交换法深度去除钼酸盐中的杂质，获得的纯净钼酸钠溶液经双极膜电解系统形成钼酸溶液，再经加入结晶助剂或加热结晶制备出高纯钼酸产品。本发明可深度去除钼中杂质、无需消耗无机酸，环境