Preparation method of ultra-coarse tungsten carbide powder

Abstract

The invention discloses a preparation method of ultra-coarse tungsten carbide powder. The preparation method comprises the following steps: evenly mixing LiOH solution or Na<2>CO<3>solution with tungsten trioxide in an atomized doping mode; adding the mixed raw material to a four-tube reduction furnace for slow-push reduction, and sieving with a 80-mesh sieve to obtain ultra-coarse tungsten powder with Fisher particle size of 30-40mum; crushing conventional carbon black to obtain fine carbon powder, mixing the fine carbon powder with the tungsten powder in a mixer for 50-70 minutes, and carrying out ball-milling on the mixed powder in a ball mill for 50-70 minutes by utilizing 60kg of a stainless steel ball to obtain evenly mixed W+C powder; adding the evenly mixed W+C powder to a high-temperature carbon tube furnace for high-temperature carbonization to obtain block tungsten carbide; and ball-milling and crushing the obtained block tungsten carbide, and then sieving with a 120 mesh sieve to finally obtain ultra-coarse tungsten carbide particles with particle size of 30-40mum. The ultra-coarse tungsten carbide powder obtained by the method has the advantages of high combined carbon content, good total carbon uniformity, high supply-state and grinding-state Fisher particle size and high primary qualification rate.

Description

technical field [0001] The invention relates to the field of preparation of ultra-coarse cemented carbide raw materials, and in particular provides a preparation method of ultra-coarse tungsten carbide powder. Background technique [0002] With the development of cemented carbide technology, the demand for tungsten carbide powder is becoming more and more polarized, that is, from fine to ultra-fine tungsten carbide powder, and from coarse to ultra-coarse tungsten carbide powder. Due to the advantages of ultra-coarse tungsten-based cemented carbide with good strength and toughness, it is more and more widely used in petroleum drilling, mining tools, stamping dies, hard surface materials and other fields. However, the production of ultra-coarse tungsten-based cemented carbide requires high-quality ultra-coarse tungsten carbide powder raw materials. The domestic traditional method of preparing ultra-coarse tungsten carbide powder is as follows: 1. Try to increase the Fischer pa...

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Problems solved by technology

[0003] The process of the traditional production method is relatively complicated, and it is difficult to solve two major problems, which seriously restrict the large-scale production of ultra-coarse tungsten carbide: 1. Due to the large amount of material charged in the production process of tungsten powder, the size of the tungsten powder particles on the surface layer and the bottom layer is different , the grain uniformity is poor, which affects the performance of subsequent alloys. Sometimes it is even necessary to adopt the method of grading and screening to obtain ultra-coarse tungsten carbide powder, resulting in low product yield and high energy consumption; Tungsten carbide powder; 2. The uniformity of ultra-coarse tungsten powder mixed with carbon black during the carbonization process is poor, resulting in segregation during the carbonization process, and black centers and interlayers appear after powder carbonization. The carbon black cannot completely penetrate, resulting in the combined carbon content of the product Low, high free carbon content, need to re-carbonize one or more times, low efficiency, high energy consumption, and the Fischer particle size of ultra-coarse tungsten carbide is also reduced in multiple crushing ball mills, which cannot reach the ultra-coarse tungsten carbide powder. standard