Expanding method of fine flake graphite and preparation method of expanded graphite board

Abstract

The invention discloses an expanding method of fine flake graphite and a preparation method of an expanded graphite board, and belongs to the field of graphite boards. In the expanding method of fine flake graphite, a chemical oxidation method is adopted for expansion, and fine flake graphite is treated by a mixed acid and a strong oxidant, wherein the addition amount of the mixed acid is 70-100 mL in per 10 g of the fine flake graphite, the addition amount of the strong oxidant is 12-15wt% of the fine flake graphite, and the mixed acid is a mixture of concentrated sulfuric acid and concentrated nitric acid at a volume ratio of (4.5-5.5):1. By utilizing the expanding method of the fine flake graphite, the fine flake graphite is expanded, and obtained fine flake expanded graphite has expansion times of 200-400, thus the obtained fine flake graphite can be pressed into a fine flake expanded graphite board; and the obtained expanded graphite board has good performance, and can be used in the field of gaskets, sealing elements, cushioning materials and the like.

Description

technical field [0001] The invention relates to a method for preparing expanded graphite plates, in particular to a method for preparing expanded graphite plates with fine scales. Background technique [0002] Existing expanded graphite is made of 80 mesh and coarse flake graphite. For example, using 32 mesh coarse large flake graphite as raw material, using concentrated sulfuric acid, concentrated nitric acid and potassium chlorate or similar strong oxidizing agents to prepare a mixed solution to treat large flake graphite to form an interlayer compound, and then place the interlayer compound Heating at high temperature (such as 950°C) for 10-20 seconds, the intercalation compound in the intercalation compound is vaporized at high temperature, and the graphite layer is broken away, so that the graphite intercalation compound expands to form expanded graphite. Expanded graphite can be made into sheets by molding. Such expanded graphite sheets have excellent properties and ...

AI Technical Summary

Problems solved by technology

[0003] However, for fine flake graphite (with a particle size of less than 80 mesh), it is difficult to make plates from it. The reason is that the expansion factor of fine flake expanded graphite is very small. If the combination is not good, the tensile performance is not good, and it is easy to disperse into particles

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