Wechat QR code
Wechat QR code
15311826613
Click to add WeChatGraphite is a kind of non-metallic mineral. It has the advantages of high temperature resistance, strong electrical and thermal conductivity, so it has been widely used in defense, metallurgical machinery and other industries. New graphites such as graphene, spherical graphite, and flexible graphite have better performance and good application prospects. With the continuous development and utilization of mineral resources, high-quality and easy-to-select graphite mines are gradually decreasing. In order to meet the needs of market production, it is imperative to develop and utilize complex and difficult-to-select graphite mines. Large-scale graphite has natural hydrophobicity and good floatability, so the flotation process can be used to recover the concentrate, while for graphite mines with smaller scales, fine embedded particles and low taste, more complex mineral processing procedures are required. It can be seen that the mineral processing process used is different according to the type of graphite ore. The following will introduce the types of graphite, graphite beneficiation methods and graphite purification technology.
1. From the perspective of industrial application, graphite deposits can be divided into five types:
1. Layered graphite deposits in schist;
2. Graphite deposits in coal seams;
3. Graphite deposits in syenite;
4. Graphite deposits in rock;
5. Vein graphite deposits in flakes.
2. From the perspective of crystallization, graphite deposits can be divided into two types: crystalline graphite ore and cryptocrystalline graphite ore.
Common graphite dressing methods include flotation, gravity separation, and electrostatic separation, among which flotation is widely used. The concentrate grade obtained by conventional graphite dressing methods is generally around 97%. If you want to obtain higher-grade graphite, you need appropriate purification methods, such as high-temperature alkali dissolution acid leaching, acid leaching, chlorination roasting, etc.
Flake graphite ore can be treated by flotation because of its good hydrophobicity. Commonly used flotation collectors are non-polar hydrocarbon oils, such as kerosene, diesel, heavy oil, etc. Some beneficiation plants use new collectors, such as phenols, sulfonates or carboxylates. While cryptocrystalline graphite ore cannot significantly improve the concentrate grade through flotation, its raw ore has a high content of fixed carbon. The concentrate and tailings obtained after flotation can be sold as products of different grades. When the content of silicate minerals in graphite ore is high, water glass, starch and cellulose can be selected for inhibition. If the pyrite content in the ore is high, quicklime can be added to the slurry to adjust the pH value and inhibit it.
Gravity separation is a method of physical separation based on the density difference between graphite ore and other gangue minerals. The components in graphite ore can be divided into three categories according to their specific gravity: heavy minerals, medium-gravity minerals, and light minerals. Then, the different specific gravities of graphite and gangue minerals are used for gravity separation to obtain graphite rough concentrate. Graphite gravity separation generally adopts wet gravity separation, and the main equipment is a shaking table. It is difficult to obtain ideal mineral processing indicators by gravity separation alone, and a combined flotation process is required, that is, after obtaining a rough concentrate by gravity separation, a flotation process is used to obtain a graphite concentrate.
The conductivity of graphite is due to other gangue minerals such as quartz, mica, and feldspar. Therefore, this feature can be used to separate graphite from other gangue minerals by electrostatic separation. Because the electrostatic separation method has a small production capacity and low efficiency, the mineral separation effect is not as good as flotation, and it is rarely used in mineral processing plants.
When deep processing graphite, it is necessary to increase the grade of graphite concentrate to more than 99%. This cannot be achieved using the conventional beneficiation methods mentioned above, so the graphite concentrate needs to be purified. The purification methods are mainly divided into two types: chemical purification and high-temperature purification.
Alkali and graphite concentrate are mixed and melted in a certain proportion. After melting, the gangue minerals react with the alkali to form water-soluble compounds. The melting reaction is carried out at 850°C. After the reaction is completed, it is washed with water. Sodium silicate is dissolved in water, and some substances are hydrolyzed in a weak alkaline medium to form highly dispersed precipitates. These precipitates are treated with high-concentration acid to prevent chemical combination, and then washed with water to obtain high-purity graphite.
The sublimation point of graphite can reach 4500°C, which is much higher than other impurities. When graphite is heated to 3000℃ in a purification furnace, substances with low boiling points evaporate, thus obtaining graphite with a purity of more than 99%. In order to improve the purity of graphite, inert gas and other agents can be introduced during the heating process to allow volatile substances to escape with the gas.
The above content is a brief introduction to graphite ore types and ore dressing and purification methods. In actual production, the ore dressing plant should select a reasonable ore dressing and purification method based on the mineral composition and characteristics of the graphite ore. Xinhai recommends conducting ore dressing tests to determine the characteristics of the graphite ore to be selected and customize the ore dressing method. Xinhai can design graphite ore dressing technology and graphite ore dressing equipment for you to help you recover graphite concentrate more efficiently, improve ore dressing efficiency and reduce resource waste.
Consultation
153-1182-6613
Consult
Message
