Graphite is a high-energy crystalline carbon material, which has high application value in high-performance materials due to its unique structure and characteristics such as conductivity, thermal conductivity, lubrication, high temperature resistance, and chemical stability. It is widely used in fields such as metallurgy, machinery, environmental protection, chemical engineering, fire resistance, electronics, medicine, military industry, and aerospace, and has become an essential non-metallic material for modern industry and the development of high, new, and cutting-edge technologies, The position in the development of the national economy is becoming increasingly important, and international industry experts predict that the 20th century will be the century of silicon, and the 21st century will be the century of carbon.

Natural graphite in China has good geological conditions, wide distribution, abundant resources, and good quality, with reserves and production ranking first in the world, making it one of China's advantageous minerals.

Natural graphite can be divided into two types based on its degree of crystallization: crystalline graphite (flake) and cryptocrystalline graphite (earthy). The characteristic of crystalline graphite ore is that its grade is not high, and the fixed carbon content generally does not exceed 10%. In locally enriched areas, it can reach 20% or more. However, this type of graphite ore has good washability, with a flotation concentrate grade of over 85%, making it one of the best floatable ores in nature. The grade of cryptocrystalline graphite is relatively high, with a fixed carbon content generally ranging from 60% to 80%, with a maximum of 95%. However, the selectivity of the ore is poor.

With the continuous development of technology, ordinary high carbon graphite products can no longer meet the requirements of various industries, so it is necessary to further improve the purity of graphite. However, the level of graphite processing technology in China is relatively low, and the products are mainly raw materials and primary products. The high impurity content of the products limits their application scope.

In this way, on the one hand, domestic graphite products have low prices in the international market, resulting in a large outflow of graphite resources; On the other hand, the high purity and ultra-fine graphite products required by the domestic market mostly rely on imports. Therefore, studying the preparation process of high-purity graphite has practical significance.

To study the method of purifying graphite, it is necessary to first investigate the composition of impurities present in graphite ore. Although the impurities in natural graphite vary from place to place, the approximate composition is similar. These impurities are mainly silicate minerals such as potassium, sodium, magnesium, calcium, aluminum, etc. The purification process of graphite is to take effective measures to remove these impurities. At present, the main methods for purifying graphite at home and abroad include flotation method, alkali acid method, hydrofluoric acid method, chlorination roasting method, high-temperature method, etc. The alkaline acid method, hydrofluoric acid method, and chlorination roasting method belong to chemical purification methods, while the high-temperature purification method belongs to physical purification methods.