低钾低钠低氯高纯仲钨酸铵制备工艺研究

Preparation Technique of High Purity APT with Low Contents of Potassium,Sodium and Chloride

随着产品工艺的发展,零级品的APT原料已不能满足高端硬质合金的生产要求。传统工艺在制取高纯仲钨酸铵时,一般使用零级品APT进行氨溶,再通过蒸发重结晶,以达到提纯的目的。研究根据离子交换法制取仲钨酸铵的原理,通过优化现有离子交换法制取仲钨酸铵工艺,过程主要包括配矿球磨、碱煮过滤、离子交换、除钼、蒸发结晶、烘干筛分等阶段,试验中通过严格控制离子交换、除钼、结晶洗涤、去离子水制备等工序的生产技术指标和所使用的各辅助材料中杂质的含量,从而达到制取低钾、低钠、低氯高纯仲钨酸铵的目的,所制取的高纯仲钨酸铵的总杂质能保证在7×10^(-5)以内,特别是ω(K)≤3×10^(-6)、ω(Na)≤2×10^(-6)、ω(Cl)≤1×10^(-5)。

With the development of technology products,the APT zero grade materials can not meet the production requirements of high-end carbide.The traditional method for the production of high purity ammonium paratungstate was to dissolve zero grade APT products,and then torecrystallize by evaporation.Based on the ion exchange theory,this study optimizes the existing ion exchange process to prepare high purity APT.Through rigidly controlling the technical index in the processes of ion exchange,evaporative crystallization,washing and deionized water preparation,and the impurity contents in the supplementary materials used in such processes,we can produce high purity APT with low contents of potassium,sodium and chlorine.The total impurity content is lower than 7 ×10^（-5）in the products obtained by the new technology.Specifically,the content of sodium,potassium,and chlorine is lower than 2×10^（-6）,3×10^（-6）,and 1×10^（-5）,respectively.