Apparatus and method for preparing ultrafine WO3

Abstract

The invention discloses an apparatus and a method for preparing ultrafine WO3, and belongs to the technical field of powder metallurgy, and the apparatus and the method can be applied to the preparation of the ultrafine WO3 powder. The apparatus comprises two liquid reservoirs for storage of reaction liquids and constant-flux pumps which are respectively connected with the liquid reservoirs, the constant-flux pumps are connected with a T-type tee by capillary tubes, the vertical end of the T-type tee is a reaction liquid outlet, and the apparatus belongs to a micro impinging stream reactor. The reaction method is as follows: a hydrochloric acid solution and a tungstate solution are impacted and mixed through the T-type tee connector to synthesize precursor tungstic acid, and the precursor tungstic acid is calcined to obtain the ultrafine WO3 powder. The preparation method and the apparatus can be used to strengthen the mixing reaction process of components to obtain the WO3 with a regular morphology, small particle size and narrow particle size range. The method has the advantages of simple process, high control precision, continuous production and many other advantages, and has a good industrialization prospect.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy, in particular to the preparation of superfine WO 3 devices and methods. Background technique [0002] Tungsten has high density, high melting point, high hardness, high wear resistance, low thermal expansion coefficient, excellent electrical and thermal conductivity, and good corrosion resistance, so it has been widely used in high-density alloys and hard alloys. With the expansion of micron and ultra-fine grain cemented carbide market, the demand for ultra-fine tungsten powder is increasing day by day. In summary, it can be mainly used in: making heat-resistant and wear-resistant alloys, aero-engines, turbine blades and other parts that are subject to strong wear, making electric light sources and heating elements, making contact alloys and high-density alloys, etc. Agglomerated tungsten powder is the key to improve tungsten-based high-density alloy and WC-Co cemented carbide. The p...

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Problems solved by technology

Although the process of preparing ultrafine tungsten powder by solid phase decomposition method is simple, some toxic gases are easy to be generated during the decomposition process, causing environmental pollution, and the generated powder is easy to agglomerate

The liquid phase method can precisely control the size of the product components and particles, mainly including: precipitation method, hydrothermal method, microemulsion method, sol-gel method, etc. The precipitation method is obtained by adding an appropriate precipitant to the metal salt solution. The precursor precipitate is dehydrated and calcined to form a nano-powder, but this method has larger particles, unstable particles, and easy agglomeration, which needs to be pulverized again, resulting in an increase in cost

Although the oxide powder particles prepared by the sol-gel method are small, the preparation process is complicated, the preparation cycle is long, and some toxic organic solvents are often added.

The product prepared by the hydrothermal method has high purity, good dispersibility, good and controllable crystal form, but its high equipment requirements, high cost, and high energy consumption limit its practical application.

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