When graphite is chemically treated, the chemical reaction is carried out simultaneously at the edge of expanded graphite and in the middle of the layer. If the graphite is impure and contains impurities, lattice defects and dislocations will appear, resulting in the expansion of the edge region and the increase of active sites, which will accelerate the edge reaction. Although this is beneficial to the formation of edge compounds, it will affect the formation of expanded graphite intercalation compounds. And the layered lattice is destroyed, which makes the lattice disordered and irregular, so that the speed and depth of chemical diffusion to the interlayer and the generation of deep intercalation compounds are hindered and limited, which further affects the improvement of expansion degree. Therefore, it is required that the content of graphite impurities must be within the specified range, especially the granular impurities must not exist, otherwise the graphite scales will be cut off during the pressing process, which will reduce the quality of the molded materials. The following Furuite graphite editor introduces that the purity of graphite raw materials affects the properties of expanded graphite:
The particle size of graphite also has a great influence on the production of expanded graphite. The particle size is large, the specific surface area is small, and the area involved in chemical reaction is correspondingly small. On the contrary, if the particle is small, its specific surface area is large, and the area for participating in chemical reactions is large. From the analysis of the difficulty of chemical substances invading, it is inevitable that the large particles will make the graphite scales thick, and the gaps between layers will be deep, so it is difficult for chemicals to enter each layer, and it is even more difficult to spread in the gaps between layers to cause deep layers. This has a great influence on the expansion degree of expanded graphite. If the graphite particles are too fine, the specific surface area will be too large, and the edge reaction will be dominant, which is not conducive to the formation of intercalation compounds. Therefore, graphite particles should not be too large or too small.
In the same environment, in the relationship between loose density and particle size of expanded graphite made of graphite with different particle sizes, the smaller the loose density, the better the effect of expanded graphite. However, in actual production, it is shown that the particle size range of graphite used is preferably from -30 mesh to +100 mesh, which is the most ideal effect.
The influence of graphite particle size is also reflected in that the particle size composition of the ingredients should not be too wide, that is, the diameter difference between the largest particle and the smallest particle should not be too large, and the processing effect will be better if the particle size composition is uniform. Furuite graphite products are all made of natural graphite, and the quality is strictly required in the production process. The graphite products processed and produced have been favored by new and old customers for many years, and you are always welcome to consult and purchase!
Post time: Mar-13-2023