What are the processing methods for graphite with different properties?
Graphite is a widely used industrial raw material. What are the different processing methods for graphite with different properties?
1. Purification and processing of graphite products
The modern graphite processing industry requires graphite products to develop in two aspects: one is to achieve high purity of large crystal scales, and the other is to require graphite product particles to be ultrafine (such as less than 1 μ m or 0.5 μ m). The main purification method for graphite is chemical purification. The most mature process for chemical purification is to melt graphite with caustic alkali at 700 ℃, wash it to neutrality, and then treat and wash it with hydrochloric acid to achieve a carbon content of 98% -99% in graphite. Some manufacturers also use hydrofluoric acid treatment to produce high-purity graphite.
2. Mineral processing methods for crystalline graphite
Crystalline graphite has good natural floatability, and in China, flotation is basically used for mineral processing. Due to the fact that the size of graphite flakes is one of its most important quality indicators, multi-stage grinding and multiple selection processes are adopted in the selection method to select large flake graphite as early as possible. The commonly used collectors for flotation are kerosene, diesel, etc. The foaming agents are No. 2 oil, No. 4 oil, etc. The adjusting agents are lime and sodium carbonate, and the inhibitor is water glass.
3. Mineral processing method for cryptocrystalline graphite
Cryptocrystalline graphite crystals are extremely small, so they are also called microcrystalline graphite. Graphite particles are often embedded in clay, making separation difficult. Due to the high grade of the raw ore (generally containing 60% -80% carbon), many graphite mines directly crush and process the extracted ore to sell graphite powder products. At present, some units are still conducting research on new processes for microcrystalline graphite flotation, such as oil agglomeration flotation.
