The production process of natural graphite mainly includes the following steps:
Raw material selection: The raw materials of natural graphite are mainly graphite ores naturally formed in nature, such as graphite schist, graphite gneiss, graphite-containing schist and metamorphic shale. These ores can be divided into crystalline graphite (flake graphite) and cryptocrystalline graphite (earthy graphite) according to their crystal form.
Mining and mineral processing: Graphite deposits are usually mined in open pits, with high recovery rates and low depletion rates. The mineral processing process mainly includes crushing, grading and flotation. Flotation is a common method to improve the purity of graphite, but it can only increase its purity to 94-98%. To produce high-purity graphite, chemical purification and other methods are also required.
Purification: Purification is a key step in improving the purity of graphite. Common purification methods include flotation and chemical purification. Flotation uses the difference in surface properties of minerals for separation, but can only achieve a certain purity; chemical purification removes impurities through acid and alkali treatment, such as caustic soda melting method, acid and alkali method, hydrofluoric acid method, etc.
Modification: In order to improve the performance of graphite, modification is sometimes required. Modification can change the surface properties and chemical composition of graphite by physical or chemical methods to meet the needs of specific applications.
Mixing and carbonization: During the production process, the purified graphite is mixed with other materials and then carbonized to obtain the desired physical and chemical properties.
Application areas of natural graphite: Natural graphite is widely used in batteries, metallurgy, chemical industry, machinery, electronics, new energy, aerospace, military industry, nuclear industry and refractory materials. In the market demand structure, refractory materials, conductive materials and sealing materials are the main application areas