Synthesis of high purity tungsten hexafluoride using metal tungsten as anodic electrolytic molten salt

Abstract

A metal tungsten plate is preferably used as an anode of an electrolytic bath, a raw material lithium fluoride beryllium eutectic is preferably used as an electrolyte, the melting point range is suitable for electrolysis and does not contain hydrogen fluoride components, and the pollution of harmful components such as carbon tetrafluoride, hydrogen fluoride and the like to the finished product tungsten hexafluoride can be cut off from the source. Tungsten hexafluoride gas generated in an electrolytic bath, entrained molten salt dust and a small amount of fluorine gas which is not reacted withmetal tungsten enter a gas purification tank along a gas outlet pipe of the electrolytic bath, and electrolyte dust entrained by the tungsten hexafluoride is removed by a dust filter plate and a dustadsorbent; a tungsten microsphere reaction layer is used for completely converting a small amount of unreacted fluorine gas into tungsten hexafluoride, and a microporous filter is used for completelyfiltering entrained tungsten particles to finally generate high-purity tungsten hexafluoride gas. The method achieves direct synthesis of the high-purity tungsten hexafluoride by an electrolytic method, and has the advantages of simple process route, less finished product impurities, high yield, extremely competitive comprehensive production cost and the like.

Description

technical field [0001] The invention relates to a device and a process 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...

AI Technical Summary

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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