Chemical processing method for preparing high quality inflatable graphite

A technology of expanded graphite and chemical treatment, applied in the field of chemical treatment for the preparation of high-quality expandable graphite, can solve problems such as waste, increase in cost, and reduce product purity.

Inactive Publication Date: 2009-06-17
晟茂(青岛)先进材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] (1) inject the concentrated sulfuric acid of 98wt% of 70kg in the reactor with metering pump;

[0021] (2) 25kg50 order graphite flakes are added in the reactor by the feeder, the reactor is sealed, the stirring is started, the vacuum pump is turned on, and the vacuum degree in the control reactor is at 150Pa;

[0022] (3) Open the feed valve of hydrogen peroxide, utilize vacuum to slowly add the hydrogen peroxide of 5kg30wt% in the reactor;

[0023] (4) The reaction time is 30 minutes;

[0024] (5) After deacidification and water washing, the pH is close to 7;

[0025] (6) After the material after the dehydration treatment is transferred to the drier, after being dried to a water content lower than 1% at a temperature of 100° C., the product with an expansion volume of 250ml / g, a volatile content of 11.5%, and a sulfur content of 1.2% is obtained. High-quality expandable graphite with low sulfur and low volatile content. Expanded at 950°C for 30s to obtain expanded ...

Embodiment 2

[0028] (1) inject the concentrated sulfuric acid of 75kg98wt% in the reactor with metering pump;

[0029] (2) 25kg80 order graphite flakes are added in the reactor by the feeder, the reactor is sealed, the stirring is started, the vacuum pump is opened, and the vacuum degree in the control reactor is at 150Pa;

[0030] (3) Open the feed valve of hydrogen peroxide, utilize vacuum to slowly add the hydrogen peroxide of 6kg30wt% in the reactor;

[0031] (4) The reaction time is 40 minutes;

[0032] (5) After deacidification and water washing, the pH is close to 7;

[0033] (6) After the material after the dehydration treatment is transferred in the drier, after drying to a water content lower than 1% at a temperature of 100° C., the obtained product has an expansion volume of 220ml / g, a volatile content of 11.0%, and a sulfur content of 1.3%. High-quality expandable graphite with low sulfur and low volatile content. The expansion is complete at 1000°C, resulting in expanded gr...

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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...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/04
Inventor 尹顺庆王京芹郭华德张鑫耿世达
Owner 晟茂(青岛)先进材料有限公司
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