Mineral dressing | Graphite ore dressing process encyclopedia

Graphite mainly refers to natural graphite, which is a non-metallic mineral formed by carbon under specific high-temperature reduction conditions, and is most commonly found in marble, schist, and gneiss.

Graphite is an important industrial mineral. Graphite has many properties such as good high temperature resistance, thermal shock resistance, electrical conductivity, lubricity, chemical stability and plasticity, so it is widely used in the fields of steel, chemical industry, machinery, electronics, aerospace, national defense and military industry.

According to the crystal form of graphite, natural graphite can be divided into crystalline graphite and cryptocrystalline graphite. The crystal diameter of graphite is greater than 1 μm, and the crystal form of crystalline graphite can be observed with the naked eye or under a common microscope. It is called crystalline graphite; the diameter of graphite crystals is less than 1 μm, and dense graphite aggregates that are difficult to discern under a microscope are called crystalline graphite. Aphanitic graphite or amorphous graphite, because aphanitic graphite is mostly black soil, it is also called soil graphite and microcrystalline graphite.

The graphite ore beneficiation process is mainly aimed at graphite ore, pyrite or mica with different crystal forms. Two combined beneficiation processes of multi-stage grinding, multi-stage flotation and gravity flotation are adopted.

This scheme is suitable for rock-type graphite processing plants. There are crushing, grinding, flotation, concentrate concentration, dehydration and other parts.

Graphite ore beneficiation process

01 The truck/excavator unloads the rough stone into the hopper, and the stone enters the vibrating feeder from the lower part of the hopper;

02 The vibrating feeder feeds the stone evenly into the primary jaw crusher;

03 The output material crushed by the primary jaw crusher will be transported to the double-layer vibrating screen;

04 Smaller fine grains go directly to the belt conveyor, and larger gravel grains enter the secondary jaw crusher. The output of the secondary jaw crusher will be conveyed to the fine ore hopper by belt conveyor.

05 The fine ore hopper also has a buffer function, and the electromagnetic vibrating feeder is used under the fine ore hopper to evenly feed the fine ore to the belt conveyor.

06 The belt conveyor transports the fine ore to the ball mill for grinding.

07 All the discharge from the ball mill enters the spiral classifier for classification, and the discharge is controlled to be less than 0.074mm (200 mesh) as much as possible.

08 The smaller output from the spiral classifier goes to the mixing tank. Larger particles are returned to the grinder again.

09 After mixing from the stirring tank, enter the first stage of flotation, including coarse flotation, fine flotation and sweeping. The tailings in the first stage enter the pump pool and are transported away by the slurry pump.

10 The concentrate from the flotation will enter the pump basin and be pumped by the slurry pump to the hydrocyclone.

11 The underflow of the cyclone enters the secondary ball mill to grind them into fine powder again to better release the inner ore. The output is returned to the hydrocyclone.

12 The cyclone overflow enters the secondary flotation (including 6 fine flotation).

13 The tailings after 6 times of fine flotation are returned to the secondary grinding stage to form a closed circuit.

14 The concentrated ore from flotation directly enters the concentrator, and the sedimented pulp enters the pump pool, and is pumped to the filter press by the pulp pump.

15 The filtered concentrate enters the dryer to obtain dry graphite concentrate.

For graphite ore containing multiple gangues, our mining engineers recommend a combined gravity and flotation process for beneficiation of graphite ore. First, gravity separation is used to separate light and heavy minerals, and after separation, flotation is used to flotation the tailings, that is, light minerals.