Tungsten Slime Treatment by High Gradient Combined Magnetic Separation

Wolframite has a large proportion and is brittle. Slime is easily produced in the process of mining and dressing. In the early stage, shaking bed and centrifugal gravity separation are mainly used to recover wolframite. Shaking bed surface zoning is obvious and easy to operate, but the unit area processing capacity is small, the recovery rate is low when treating fine mud, and metal is easily lost from fine mud. Although centrifugal concentrator has large processing capacity and high recovery efficiency for fine mineral particles, its water consumption is large, and it is difficult to achieve ideal indicators in actual industrial production.

It is well known that wolframite has weak magnetism. Therefore, some scholars have proposed a method, high gradient combined magnetic separation, which can control cost and improve tungsten recovery effectively. The steps include:

1)The tungsten slime in wolframite concentrator is concentrated by a concentrator, stirred in a stirring barrel, and the slurry flow rate and feed concentration are controlled (20%). Strong magnetic minerals such as iron are removed by a weak magnetic machine.

2)The low-intensity magnetic tailings are fed into the cylindrical separator to remove + 1.2mm grain size in order to avoid blocking the high-intensity magnetic separator, and then high-gradient pulsating high-intensity magnetic separator is used for high-intensity magnetic separation to obtain the coarse concentrate containing WO3.6.11%.

3)High-intensity magnetic tailings (WO₃ grade 0.13%) can be further enriched and recovered by suspended cone concentrator (cone diameter is 4 meters, walking speed is 1.0 rotate/minute, vibration speed is 400 rotate/minute). Coarse concentrate 2 containing WO₃ 1.54% and tailings WO₃ grade is 0.06%.

4)The first coarse concentrate and the second coarse concentrate are merged into the sludge hopper to concentrate and dehydrate. The weight concentration of the discharged ore is 15.6%. After classification by hydraulic classifier, the coarse grade (+0.037mm) enters the 6-S shaking bed (inclined 121 slots), the fine grade (-0.037mm) enters the 6-S shaking bed (inclined 151 slots), and the shaking bed concentrate is merged into the final concentrate. Its WO₃ grade is 30.0%, and the WO₃ recovery rate is 90.01%.

5)Medium ore and tailings produced by coarse-grained shaking bed and fine-grained shaking bed flow into the middle ore pond and are pumped to the thickener by slurry pump.

High gradient combined magnetic separation is an environmentally friendly, simple and excellent beneficiation method. It can directly utilize tungsten slime from wolframite concentrator or fine wolframite after grinding, concentrate by concentrator and enter the process system. It can be pre-enriched by high intensity magnetic machine, and the enrichment ratio is more than 10. Then the fine wolfram in high intensity magnetic tailings can be further recovered by suspended vibration cone separator. Coarse concentrate is merged and classified into shaker for coarse and fine separation, and the medium ore and tailings produced by coarse and fine shaker are concentrated back to densifier, forming closed loop to ensure wolfram does not lose with shaker tailings. Wolframite slime containing WO₃ 0.4 was treated by high gradient combined magnetic separation in a concentrator in Hunan Province. The tungsten concentrate with a grade of about 30% was obtained, and the WO₃ recovery rate was over 90%.

• < Prev
• Next >