In the processing and production of expanded graphite, the purity and granularity of the graphite itself should be taken into account. These factors have a great influence on the processing of expanded graphite.
The purity of graphite should be considered in the processing of expanded graphite.
The key to the expansion of graphite is to form a large number of interlaminar compounds, and when graphite is treated by wet chemistry, the chemical reactions in the system can be carried out simultaneously in the edge region and interlaminar region of graphite. If the graphite is not pure, there are many lattice defects and dislocation caused by impurities. As a result, the number of active points in the edge area increases, and the chemical reaction speed of the edge increases. The impurity, on the other hand, also make the layer structure of graphite crystal disorders and incomplete, spread the chemicals to the speed and depth of interlayer by barriers and restrictions, not more deep formation in the interlayer compounds, decrease the expansion of the expanded graphite cubage, so to get the expanded graphite with good quality must adopt high purity of raw materials. The general purity must be above 99% to get better results.
The size of graphite should be considered in the processing of expanded graphite.
The particle size of graphite has a great influence on the expansion volume. The particle size of graphite is too large or too small. The particle size is too fine, the specific surface area is large, and the edge effect of graphite is significant, which is not conducive to the formation of interlaminar compounds. Generally, the particle size of graphite raw materials is about 30 meshes.