Using metal tungsten as anode to electrolyze molten salt to synthesize high-purity tungsten hexafluoride

Abstract

The metal tungsten plate is preferred as the anode of the electrolytic cell, and the raw material lithium beryllium fluoride eutectic is preferably used as the electrolyte. The melting point range is suitable for electrolysis and has no hydrogen fluoride component. It can cut off harmful components such as carbon tetrafluoride and hydrogen fluoride from the source. pollution. The tungsten hexafluoride gas generated in the electrolytic cell, the entrained molten salt dust and a small amount of fluorine gas that has not reacted with metal tungsten enter the gas purification tank along the gas outlet pipe of the electrolytic cell, and the tungsten hexafluoride is removed by the dust filter plate and dust adsorbent Entrained electrolyte dust; use tungsten microsphere reaction layer to convert a small amount of unreacted fluorine gas into tungsten hexafluoride, use a microporous filter to filter out all entrained metal tungsten particles, and finally produce high-purity hexafluoride Tungsten gas. The invention realizes the direct synthesis of high-purity tungsten hexafluoride by electrolysis, and has the advantages of simple process route, less impurities in the finished product, high yield, highly competitive comprehensive production cost and the like.

Description

technical field [0001] The invention relates to a device for directly synthesizing high-purity tungsten hexafluoride by electrolyzing molten salt. Background technique [0002] Tungsten hexafluoride (WF 6 ) is the only stable and industrially produced variety of tungsten fluorides so far. There are many important uses; for example, the tungsten / rhenium composite coating is prepared by the CVD process of mixed metals, which can be used in the manufacture of solar energy absorbing materials and X-ray emitting electrodes; making tungsten generate hard tungsten carbide on the surface of steel, copper or other metals It can be used to improve the surface properties of metals and to manufacture various special-shaped tungsten parts such as tungsten tubes, tungsten nozzles and tungsten crucibles. WF 6 In the electronics industry, it is also widely used as a raw material for semiconductor electrodes and conductive pastes, especially tungsten disilicide (WSi) made of it. 2 ), oft...

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Problems solved by technology

[0011] Patent CN1281823A discloses a method for producing ultra-high-purity (UHP) tungsten hexafluoride. The method is to first distill crude tungsten hexafluoride to separate non-volatile metal impurities in tungsten hexafluoride, and then pass through fluorine salt After adsorption, HF is removed, and finally the high-purity tungsten hexafluoride product is separated by UHP helium bubbling system. This method does not improve the purity of tungsten hexafluoride from the source, but uses cumbersome purification procedures to improve The purity of tungsten oxide is extremely expensive to produce

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