Chemical processing method for preparing high quality inflatable graphite

Abstract

The invention discloses a chemical treatment method for preparing high-quality expandable graphite. The method adopts concentrated sulfuric acid as an intercalator and hydrogen peroxide as a catalyst to prepare the high-quality expandable graphite under the vacuum condition. Because water has constant boiling point under the condition of constant vacuum degree, the reaction temperature can be well controlled and simultaneously stable reaction temperature can be maintained by utilizing vacuum to bring away heat exhausted during reaction in time. The method can obtain the high-quality expandable graphite of which the volatile component is less than 12 percent and the sulfur content is less than 1.5 percent, and the sulfur content can be less than 800 ppm after the high-quality expandable graphite is treated for 30 seconds at a high temperature of between 900 and 1,000 DEG C.

Description

technical field [0001] The invention relates to a chemical treatment method for graphite, in particular to a chemical treatment method for preparing high-quality expandable graphite. Background technique [0002] Expandable graphite is an important inorganic non-metallic material that has emerged in the past two decades. It has been widely used in chemical industry, metallurgy, power machinery, aerospace, and atomic energy industries since its inception, showing strong vitality and market application prospects. It is mainly used for dynamic and static sealing of equipment, and is the best material to replace asbestos sealing materials that are prone to cancer. However, the volatile content of expandable graphite prepared by traditional methods is as high as 25-30wt%, and the sulfur content is as high as 3.0-4.5wt%. If the time is prolonged, the sealing effect will be greatly damaged, and even cause leakage accidents. Graphite rapidly expands along the C-axis direction to f...

AI Technical Summary

Problems solved by technology

The disadvantages of this technology are: 1. Perchloric acid is prone to explosion when decomposed at high temperature, and the yellow smoke released during decomposition is irritating to the skin and mucous membranes, especially eroding the eyes and nasal cavity mucous membranes. The operation is dangerous and the requirements for equipment are relatively high. High; 2. The addition of potassium permanganate will increase the ash content of flake graphite and reduce the purity of the product; 3. The price of perchloric acid and potassium permanganate is very high, which greatly increases the cost of the product

[0006] The Chinese Patent Publication No. is CN1623895A patent literature, discloses the technical scheme of "the method for using sulfuric acid hydrogen peroxide to manufacture low-sulfur expandable graphite". After washing and drying, low-sulfur expandable graphite can be made into low-sulfur expandable graphite. The disadvantages of this technology are: 1. When hydrogen peroxide and sulfuric acid are mixed, heat is released violently, and hydrogen peroxide is easy to decompose when heated, so hydrogen peroxide cannot fully participate in the reaction, resulting in a certain amount of waste; 2. The reaction process is an exothermic reaction. As the reaction progresses, the reaction temperature continues to rise, resulting in uncontrollable intercalation of the product