Preparation method for tungsten hexafluoride gas

Abstract

The invention provides a preparation method for tungsten hexafluoride gas, relating to fluoride of tungsten. The preparation method comprises the following steps of accessing hydrogen fluoride into an electrolytic bath to prepare fluorine electrolytically; by passing through a purifying purified tower, a first in-depth cooling tank and a second in-depth cooling tank in sequence, purifying the produced low-purity fluorine gas; accessing the purified fluorine gas to a reaction system to perform reaction, generating a crude product, namely tungsten hexafluoride; accessing the purified fluorine gas to a first horizontal fixed fixing bed reactor and a second horizontal fixed fixing bed reactor which are filled with waste tungsten cutting heads to perform reaction; collecting the prepared tungsten hexafluoride gas by a primary condenser, an intermediate condenser and a senior condenser in sequence; respectively unfreezing the collected tungsten hexafluoride gas to flow to a first storage tank, a second storage tank and a third storage tank to collect, discharging the uncondensed or unreacted impurity gas to a spraying tower through a tail part pipeline to perform alkali liquid absorption, heating the crude product tungsten hexafluoride collected by the first storage tank, the second storage tank and the third storage tank, and distilling the heated tungsten hexafluoride to a rectifying tower through a filter to perform rectifying and purifying. By utilizing the waste tungsten cutting heads, the preparation method provided by the invention has the advantages of safe process operation and high purity.

Description

technical field [0001] The invention relates to a tungsten fluoride, in particular to a method for preparing tungsten hexafluoride by using waste tungsten cut ends. Background technique [0002] Among tungsten fluorides, tungsten hexafluoride (WF 6 ) is the only species that is stable and industrially produced. Its main use is as a raw material for the metal tungsten chemical vapor deposition (CVD) process in the electronics industry, especially WSi made of it 2 It can be used as a wiring material for large scale integration (LSI). The composite coating of tungsten and rhenium is prepared by mixed metal CVD process, which can be used in the manufacture of X-ray emitting electrodes and solar absorbers. In addition, WF 6 In the electronics industry, it is also mainly used as a raw material for semiconductor electrodes and conductive pastes. WF 6 There are also many applications in non-electronic industries, such as tungsten can generate hard tungsten carbide on the surfa...

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Problems solved by technology

The purity of primary synthesized tungsten hexafluoride gas will directly affect the purity of high-purity tungsten hexafluoride gas. the cost will be high

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