Raw Materials and Processing Equipment of Spherical Graphite
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Update time : 2022-01-11 12:02:33
Spherical graphite is made of high-quality high-carbon natural flake graphite as raw material, and the surface of graphite is modified by advanced processing technology to produce graphite products with different fineness and elliptical spherical shape. Spherical graphite material has the characteristics of good electrical conductivity, high crystallinity, low cost, high theoretical lithium intercalation capacity, low and flat charge and discharge potential, and is currently an important part of the negative electrode material for lithium ion batteries.
Spherical graphite processing principle: First, pulverize the natural flake graphite powder into a suitable particle size, and then carry out the processing of de-angularization, so that it will finally form an ellipsoid or spherical shape. The fine powder peeled off during the process is separated, and the normal distribution of spherical graphite can be obtained.
Selection criteria for spherical graphite raw materials:
The particle size of the spherical graphite raw material should be appropriate. Too coarse particle size has a higher cost; too fine particle size affects the yield of spherical graphite, and too many auxiliary products will increase the cost of raw materials. Studies have shown that it is more suitable to use raw materials with a particle size of -100 mesh to produce spherical graphite.
The carbon content of spherical graphite raw materials is also a very important factor. The higher the carbon content, the higher the cost of raw materials, the lower the carbon content, the increase in the number of purification passes, which will also increase the wear and tear of the equipment, and the total cost will also increase. After practice and accumulation, it contains 95%~96% of raw materials, and the comprehensive cost is the lowest.
Selection criteria for spherical graphite processing equipment:
In the spherical process, the airflow vortex pulverizer is used more, which has both the performance of pulverization and the effect of de-angularization. In addition, the quality of the grading equipment will directly affect the output rate of spheroidized graphite and the control of technical indicators of spheroidal graphite, so it should be paid attention to when choosing.
The purity requirements of graphite anode materials for lithium-ion batteries are often above 99.95%. Therefore, the purification process is essential and crucial in the entire production process. At present, the production of high-purity spherical graphite is generally produced by chemical purification methods, and the chemical raw materials used are all strong acids, so the purification equipment must be acid-resistant and corrosion-resistant. At the same time, because the chemical purification is completed at a certain temperature, the equipment also has a certain high temperature resistance.
After the chemical reaction, the impurities in the spherical graphite are dissolved in the reaction solution, and the impurities can be taken away only by washing. The washing equipment used in the process mainly includes filter press and centrifuge. The advantages of the filter press are high recovery rate, less running material, low labor intensity, safety and easy operation, but the disadvantage is that the washing effect is relatively poor, and there are dead corners that cannot be washed. The advantage of the centrifuge is that the washing is more sufficient and the effect is good, but there are also many disadvantages, such as a large amount of material running, a large waste, high labor intensity when discharging, and the safety workability is not as good as that of a filter press, and it wastes more water. Combining the two works well.
The purified and washed spherical graphite is dried to remove moisture, and the moisture is controlled below 0.5%. In the drying process, the most likely problem is secondary pollution, that is, after the spherical graphite is dried, it becomes a substandard product due to the inclusion of impurities, which is mainly manifested in the unqualified indicators of carbon content and trace elements. More drying equipment is used, such as drying kiln, microwave dryer and drying furnace.
Luoyang Trunnano Tech Co., Ltd (TRUNNANO) is a professional Spherical graphite supplier with over 12 years experience in chemical products research and development. We accept payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
