Tungsten Cobalt Alloy Discarding Tungsten and Cobalt

Tungsten cobalt cemented carbide is mainly tungsten. Because of the advantages of rich tungsten mineral resources in China, in the early development of hard alloy industrial process, the waste hard alloy is not paid much attention to. The upstream industry of the hard alloy is overdue to the excessive exploitation of tungsten mineral resources, the management is chaotic, the waste of resources is serious, most of the raw raw material is high quality. It is used only to produce low-grade alloys.

At present, China's tungsten resources are on the verge of exhaustion. At the same time, with the demand for the concept of new energy vehicles, the price of cobalt has turned five times a year, and China's Cobalt resource is extremely short, and has been relying on imports from Africa. Therefore, cemented carbide recycling has also attracted the attention of the industry. In recent years, domestic enterprises, universities and scientific research institutes have made great efforts to carry out the recycling of waste cemented carbide, and have made great progress. At present, the recycling methods of industrial waste hard alloys include nitrocnite, sodium sulphate melting, chlorination, phosphoric acid leaching, high temperature treatment, crushing, electric solution, zinc melting and redox.

A method of recovering tungsten carbide and metal cobalt from waste tungsten cobalt alloy is introduced in this paper. The process includes cleaning dry tungsten cobalt hard alloy and extracting cobalt from graphite crucible in vacuum. The porous structure of tungsten carbide is obtained from the crucible. Loose porous tungsten carbide is crushed and lapping tungsten carbide powder, and cobalt powder is condensed and crystallized in the cobalt mould. The concrete steps are as follows:

(1)To clean waste tungsten cobalt cemented carbide with hard alloy cleaning agent solution and clean water, dry and clean raw materials, the solution temperature of the hard alloy cleaning agent is 35~50, the water temperature is 50~70 C, the cleaning process is constantly stirred, and the ultrasonic generator is opened, the frequency is 20 ~ 30kHz.

(2)Step (1) the clean raw material is placed in the graphite crucible of the internal thermal vacuum resistance furnace. The vacuum is evacuated and the pressure in the furnace is below 10Pa. The heating system is started. The heating system is heated to 400~450 degrees C and 10 ~ 40min at the temperature of 2~10 /min. The heat preservation process is below 1Pa, and the high vacuum system is started. The temperature is over. The heating rate was raised to 1500~1800 C at a temperature of 2~10 /min. The temperature reached 1500~1800 degrees centigrade, the thermal insulation reaction was 0.5 to 5h, and the reaction ended. After cooling to room temperature, the material is removed and loose porous tungsten carbide is obtained from the crucible, and cobalt powder is obtained from the cobalt crystallizer.

(3)Tungsten carbide powder with porous structure is prepared by grinding tungsten carbide for 4-30 hours. Tungsten carbide powder is mixed with cobalt powder and other metal powder for cemented carbide production.

This method is strong, simple, low energy consumption, low pollution, no pollution, high recovery, low cost and large size. It is a high efficiency and green recovery method of waste tungsten cobalt hard alloy.

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