Continuous preparation method of tungsten carbide powder

Abstract

The invention relates to a continuous preparation method of tungsten carbide powder. The method comprises the steps that tungsten carbide powder is prepared continuously through adopting the way that boats and a heating element are in non-contact relative movement and an induction heating vertical continuous carbide furnace with a uniform temperature field with the temperature of 1,200 to 2,600 DEG C, tungsten powder and carbon powder are uniformly mixed to obtain a mixture, the mixture is put in the boats which are stacked up and down mutually, the boats pass through a continuous carbide furnace step by step in sequence from top to bottom, continuous carbonization heating is finished under the conditions that protective gas is filled in the continuous carbide furnace and the heating time and the heating temperature can be controlled and regulated, and the mixture is cooled to obtain a tungsten carbide product, and in each step of the boats, one boat enters from the upper part of the carbide furnace and another boat exits out of the lower part of the carbide furnace, so that the continuous preparation of tungsten carbide powder is realized. The tungsten carbide powder is prepared by adopting a vertical superhigh-temperature continuous heating way in a nitrogen environment, which breaks through the traditional preparation technology mode that the tungsten carbide powder is prepared by adopting a horizontal continuous heating process or a vertical intermitting heating process in the hydrogen environment.

Description

technical field [0001] The invention relates to a continuous preparation method of tungsten carbide powder, in particular to a continuous preparation method of tungsten carbide powder used in the cemented carbide industry to produce coarse-grained tungsten carbide as an important raw material of cemented carbide. Background technique [0002] The preparation process of coarse-grained tungsten carbide requires the carbonization furnace to provide a uniform temperature field with an amplitude as high as 2500°C. It is difficult to find a suitable carbonization furnace under such harsh production conditions. At present, horizontal continuous furnaces and vertical gap furnaces are generally used to realize the carbonization process. Both of them have the major defects of high temperature and uneven temperature, which seriously affect the consistency of performance indicators and quality stability of coarse-grained tungsten carbide powder. In the absence of high-temperature conditi...

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Problems solved by technology

[0002] The preparation process of coarse-grained tungsten carbide requires the carbonization furnace to provide a uniform temperature field with an amplitude as high as 2500°C. It is difficult to find a suitable carbonization furnace under such harsh production conditions. At present, horizontal continuous furnaces and vertical gap furnaces are generally used to realize the carbonization process. Both of them have the major defects of high temperature and uneven temperature, which seriously affect the consistency of performance indicators and quality stability of coarse-grained tungsten carbide powder. In the absence of high-temperature conditions, enterprises generally adopt The method of 2000 ℃ temperature + hydrogen is used to produce coarse-grained tungsten carbide products (some also add crystal growth agents). The reason is that hydrogen can promote the growth of tungsten carbide powder grains, and can obtain larger grain sizes at lower temperatures. Coarse crystalline tungsten carbide powder, but the tungsten carbide product produced by this method of low temperature + accelerator is a kind of puffiness, with low density and many holes inside the crystal

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