Green Recycling of Tungsten Waste

Owing to the extensive exploitation of tungsten ore, the amount of tungsten raw resources has decreased sharply. In the face of the continuous reduction of tungsten resources, the recovery of tungsten from tungsten waste has become an important breakthrough to alleviate the shortage of raw materials. The hard alloy grinding material is the main source of tungsten recovery because of the high grade of tungsten.

Many enterprises improve the methods of waste tungsten refining and choose another way to achieve environmental recycling. A well-known recycling enterprise in China has developed a method of environmental protection and recovery of ammonium partrunate from waste tungsten.

Sizing material: the cemented carbide grinding material is taken and water is added to it, and the slurry is made. The ratio of cemented carbide grinding material to water is 1:1 to 1:4.

Acid leaching: the slurry into the heating reactor and leaching, acid and separation of leached slag; acid leaching solution pH of 1 or less, the heating temperature is 60~85 DEG C.

Oxidation: the leaching residue is dried and broken, then roasted in rotary furnace, and the material is kept at high temperature for 3 ~ 10h, and the oxidizing material is obtained. The solid-liquid mass ratio of oxidizing material to water is 1: (2~4), the heating temperature is 80~100 degrees, and the reaction time is 1 ~ 3H.

Alkali leaching: adding water to the oxide material, mixing after adding liquid, and heating the reaction by alkaline leaching solution;

Ion exchange transformation: after filtrate and dilute the filtrate, the diluent is adsorbed and analyzed by ion exchange resin, so that the sodium tungstate solution can be transformed into ammonium tungstate solution.

Purification and removal of impurities: adding vulcanizing agent to ammonium tungstate solution, removing impurities such as molybdenum by ion exchange method after static thioization, and purifying ammonium tungstate solution;

Evaporation crystallization: Purified ammonium tungstate solution was placed in a crystallizer, slowly warming 80 ~ 100 ℃ after holding 3 ~ 6, ammonium paratungstate can be obtained.

Through technological process innovation, the above processes can effectively reduce energy consumption, and the process is simple. The most important thing is to substantially reduce the emissions of exhaust gas, and also successfully avoid emissions of toxic gases such as NOx and SO2, which can effectively adapt to future environmental standards.

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