Process and method of graphite ore beneficiation

Graphite is a widely used non-metallic mineral, with excellent properties such as high temperature resistance, electrical conductivity, thermal conductivity, lubrication, and chemical stability. The beneficiation process of graphite ore is mainly flotation, and the conventional method is to use a flotation reagent to achieve separation. This article will introduce the beneficiation process and method of graphite ore.

1. Crushing and grinding stage

The crushing and grinding stage is the preparation work before the beneficiation process. It aims to crush and grind the graphite ore to the proper size, which is suitable for the beneficiation process. The crushing and grinding process can be divided into three stages: coarse crushing, medium crushing, and fine crushing.

2. Flotation stage

The flotation stage is the main method for graphite ore beneficiation. In the flotation process, the graphite ore is firstly ground to a suitable fineness, and then mixed with water and flotation reagents to stir and inflate. At this time, the graphite particles will selectively adhere to the bubbles and float to the surface of the flotation cell, while the impurities will sink to the bottom of the cell. After that, the flotation foam containing graphite is collected and dried to obtain the graphite concentrate.

There are two main types of flotation methods: direct flotation and reverse flotation. The direct flotation method is suitable for the flotation of raw ore with a large amount of impurities, while the reverse flotation method is suitable for the flotation of raw ore with a high grade of graphite.

3. Chemical purification

After flotation, the graphite concentrate needs to be purified further. Chemical purification is a commonly used method to increase the carbon content of graphite. The main methods include acid leaching, alkali roasting, and high-temperature purification.

Acid leaching is a method of removing impurities from graphite by treating the graphite concentrate with acid. The commonly used acids are hydrochloric acid, sulfuric acid, and nitric acid. This method has the advantages of low cost and simple operation, but it also has certain disadvantages, such as environmental pollution, and the quality of the graphite after purification is not very good.

Alkali roasting is a method of removing impurities from graphite by roasting the graphite concentrate with an alkali metal compound, such as sodium hydroxide or potassium hydroxide. This method has the advantages of high purity, good quality, and environmental protection, but the equipment investment is high, and the operation is complicated.

High-temperature purification is a method of purifying graphite by high-temperature treatment. The commonly used methods are graphitization and annealing. Graphitization can improve the crystalline structure and purity of graphite, but it requires high temperature and long time. Annealing can also remove impurities and improve the quality of graphite, but it requires less time and lower temperature than graphitization.

4. Drying and screening

After chemical purification, the graphite concentrate needs to be dried and screened to obtain the final product. The drying method can be divided into natural drying and mechanical drying, and the screening method can be divided into wet screening and dry screening. The specific method depends on the requirements of the product.

In conclusion, the beneficiation process of graphite ore mainly includes crushing and grinding, flotation, chemical purification, drying, and screening. Among them, flotation is the main method to obtain graphite concentrate, and chemical purification can further improve the quality of graphite. With the development of technology, new beneficiation methods will continue to emerge, which will further improve the efficiency and quality of graphite beneficiation.