Preparation method of high-purity tungsten powder

Abstract

The invention discloses a preparation method of high-purity tungsten powder. The high-purity tungsten powder preparation process is short, industrialized batch production can be achieved, and the costis low. Commercial ammonium paratungstate is selected as raw materials and directly subjected to ammonia solution filtering, an ammonium tungstate solution is prepared, after crystallizing, filtering, washing and drying are conducted, ammonium paratungstate is prepared again, then hydrogen gas reduction is conducted in a reduction furnace of a metal furnace tube, and the high-purity tungsten powder is prepared. According to the preparation method of the high-purity tungsten powder, the ammonium paratungstate calcining step is omitted, and the introduced quantities of impurities in the calcining process can be decreased; and general technicians in the field can know that commercial common tungsten powder is obtained through hydrogen gas reduction by taking ammonium paratungstate as the rawmaterials, in the preparation method, a recrystallized product is still ammonium paratungstate, and the high-purity tungsten powder can be conveniently prepared by adopting a common tungsten powder reduction technology.

Description

technical field [0001] The invention belongs to the technical field of tungsten powder preparation, and in particular relates to a preparation method of high-purity tungsten powder. Background technique [0002] In the semiconductor industry, a variety of high-purity metal targets are required, with a purity of more than 99.999%. Among them, high-purity copper targets, high-purity aluminum targets, high-purity titanium targets, and high-purity tantalum targets are used in large quantities. target etc. In comparison, high-purity tungsten targets, high-purity tungsten-titanium targets and high-purity tungsten-silicon targets are less used, but they are irreplaceable in applications such as memory and chips, and are used as wiring materials and diffusion barriers. [0003] In the semiconductor industry, the purity of high-purity tungsten targets, high-purity tungsten-titanium targets and high-purity tungsten-silicon targets is required to be above 99.999%, which requires the p...

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Problems solved by technology

US4762695 discloses tungsten powder or tungsten oxide powder using H 2 o 2 Decompose, and then use ion exchange process to purify, obtain ammonium tungstate after evaporation and crystallization, and obtain high-purity tungsten powder after hydrogen reduction. This method is costly and difficult to produce in batches

CN10125938A discloses a method of chemical cleaning combined with hydrothermal reaction to prepare high-purity tungsten powder. Firstly, a tungstate solution is prepared, the solution is pressurized at 20-40MPa, and after hydrothermal reaction at 120-200°C, it is cleaned and dried with deionized water The precursor is obtained, and the precursor is reduced to obtain high-purity tungsten powder; this method has a complicated process route and is not suitable for mass production

CN103302299A discloses the method of "ammonia dissolution-recrystallization method" to prepare high-purity tungsten powder. Ammonium paratungstate is used as raw material, and tungsten oxide is obtained after calcining; ammonia dissolution, filtration, recrystallization and drying are carried out to obtain ammonium metatungstate; Hydrogen reduction in the quartz furnace tube produces high-purity tungsten powder; this scheme has a long process, the output of ammonium metatungstate is small and unstable, and the reduction furnace of the quartz furnace tube is too small to carry out mass industrial production

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