A kind of preparation method of refractory metal boride

Abstract

The invention relates to a preparation method of refractory metal (Ti, Zr, Hf, V, Nb,Ta and Cr) borides, and belongs to the field of inorganic chemistry. The existing industrially prepared refractorymetal borides are mainly synthesized by a carbon heat reduction method or a direct element synthesis method; the method has the problems of low product purity, great granularity, high equipment cost and the like. The method uses calcium hexaboride (CaB6) powder and refractory metal oxides as raw materials; corresponding refractory metal borides are produced through high-temperature reaction undercertain conditions; the high-temperature reaction products are subjected to acid soaking to remove soluble impurities; through filtering, rinsing and drying, the high-purity refractory metal borides are obtained. The method belongs to a novel method for synthesizing refractory metal boride powder. Compared with other methods, the method has the advantages that the reaction product purity is high;the cost is low; the method is flexible.

Description

technical field [0001] The invention belongs to the field of inorganic chemistry and discloses a method for preparing refractory metal borides, in particular to a method for preparing refractory metal borides by using calcium boride powder and refractory metal oxide powder as raw materials. Background technique [0002] Refractory metal borides generally have the characteristics of high melting point, good electrical and thermal conductivity, high hardness and strong corrosion resistance. They are special materials used in extreme conditions such as ultra-high temperature, high-temperature electrolysis, oxidizing atmosphere, and erosive environment. The preparation methods of refractory metal boride powders that have been proposed so far mainly include direct elemental synthesis, boron thermal reduction, carbothermal reduction, magnesium thermal reduction, electrolysis and gas phase synthesis. Current industrial production (in the case of TiB with larger output 2 For exampl...

AI Technical Summary

Problems solved by technology

The carbothermal reduction method uses refractory metal oxides, boron carbide (or boron oxide) and carbon as raw materials to react under high temperature conditions, and the residual carbon in the reaction is difficult to remove, resulting in limited product purity.