Sodium tungstate发表评论(0)编辑词条

Sodium tungstate, Na2WO4, a tungstate of sodium, is useful as a source of tungsten. It is prepared from tungsten ores used to manufacture tungsten by reducing it.
It is often found as the dihydrate, Na2WO4•2H2O. This salt is soluble in water and is a moderately strong oxidizing agent, but finds no common use in the chemistry laboratory. Like the molybdate, the deep-coloured complex tungstate(VI,V) is formed on reducing the compound with a very mild reducing agent, such as complex organic compounds. It is also thought to be a possible inhibitor of protein-tyrosine phosphatase (PTPase).It is also sometimes used as a fireproofing agent.
In organic chemistry, sodium tungstate is used as catalyst for epoxidation of alkenes and oxidation of alcohols into aldehydes or ketones.

钨酸钠
分子式: 有二水物和无水物二种,二水物分子式为Na2WO4•2H2O ,无水物分子式为Na2WO4
分子量: 二水物为329.86 ,无水物为293.86
性状:　白色具有光泽的片状结晶或结晶粉末，溶于水呈微碱性(PH8.5-9),不溶于乙醇， 微溶于氨。在空中风化。加热到100℃失去结晶水而成无水物。与强酸(氢氟酸除外)反应生成不溶于水的黄色钨酸, 与磷酸或磷酸盐反应生成磷钨杂多酸络合物, 与酒石酸、柠檬酸、草酸等有机酸反应生成相应有机酸络合物。
规格: 商品钨酸钠纯度一级品≥ 99.5 % , 二级品≥98.5 % 杂质成分符合国家标准或用户要求。
用途: 主要用于制取仲钨酸铵及深度加工制取三氧化钨、金属钨、碳化钨、硬质合金、钨条、钨丝等,制偏钨酸铵、钨酸及其它钨化合物用于石油化工、电镀、纺织、阻燃剂、水处理、染料、颜料、油墨等方面。
主要工艺原理: 通常采用钨精矿为原料与烧碱一起压煮,使钨转化为可溶性的钨酸钠,经过滤--离子交换等工艺分离矿物中的杂质成分,再经蒸发结晶--烘干得到白色结晶的钨酸钠产品。