Preparation of expandable graphite at low-temperature

An expanded graphite and low-temperature technology, which is applied in the field of preparation of low-temperature expandable graphite, can solve the problems of high cost of low-temperature expandable graphite, high concentration of perchloric acid, and high price of perchloric acid, and achieves a wide range of oxidation temperatures and less dosage , The effect of easy process control

Inactive Publication Date: 2006-09-27
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Simultaneously, the perchloric acid concentration that this method adopts is high (70%~72%), and consumption is large
Due to the high price of perchloric acid, especially high-concentration perchloric acid, which is much higher than other acids, the cost of low-temperature expandable graphite prepared by this method is high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Example 1 A mixed acid solution was prepared by mixing a perchloric acid solution with a mass concentration of 72% and a phosphoric acid solution with a mass concentration of 85% in a ratio of 1:0.02 by mass of the perchloric acid solution to the phosphoric acid solution, that is, mixing HClO in acid solution 4 : H 3 PO 4 The mass ratio is 1:0.024, HClO 4 And H 3 PO 4 The total mass concentration of 72.2%. According to the ratio of mass ratio of natural phosphorus flake graphite: perchloric acid-phosphoric acid mixed acid solution: potassium permanganate of 1:2.5:0.1, the perchloric acid-phosphoric acid mixed acid solution and potassium permanganate are mixed first, Then, 50 mesh natural phosphorous flake graphite is added and mixed uniformly, and reacted at 35° C. for 90 minutes to prepare low-temperature expandable graphite. The prepared low-temperature expandable graphite has an expansion volume of 85mL / g when expanded at 250°C, 105mL / g when expanded at 300°C, and 170mL / ...

Embodiment 2

[0024] Example 2 A mixed acid solution was prepared by mixing a perchloric acid solution with a mass concentration of 72% and a phosphoric acid solution with a mass concentration of 85% in a ratio of 1:0.05 by mass of the perchloric acid solution to the phosphoric acid solution, that is, mixing HClO in acid solution 4 : H 3 PO 4 The mass ratio is 1:0.059, HClO 4 And H 3 PO 4 The total mass concentration of 72.6%. According to the ratio of mass ratio of natural phosphorus flake graphite: perchloric acid-phosphoric acid mixed acid solution: potassium permanganate of 1:2.5:0.1, the perchloric acid-phosphoric acid mixed acid solution and potassium permanganate are mixed first, Then, 50 mesh natural phosphorous flake graphite is added and mixed uniformly, and reacted at 35° C. for 90 minutes to prepare low-temperature expandable graphite. The prepared low-temperature expandable graphite has an expansion volume of 130mL / g when expanded at 250°C, 165mL / g when expanded at 300°C, and 240mL...

Embodiment 3

[0025] Example 3 A mixed acid solution was prepared by mixing a perchloric acid solution with a mass concentration of 72% and a phosphoric acid solution with a mass concentration of 85% in a ratio of 1:0.5 by mass of the perchloric acid solution to the phosphoric acid solution, that is, mixing HClO in acid solution 4 : H 3 PO 4 The mass ratio is 1:0.59, HClO 4 And H 3 PO 4 The total mass concentration of 76.3%. According to the mass ratio of natural phosphorus flake graphite: perchloric acid-phosphoric acid mixed acid solution: potassium permanganate at a ratio of 1:1.5:0.1, the perchloric acid-phosphoric acid mixed acid solution and potassium permanganate are mixed first, Then, 50 mesh natural phosphorous flake graphite is added and mixed uniformly, and reacted at 35° C. for 90 minutes to prepare low-temperature expandable graphite. The prepared low-temperature expandable graphite has an expansion volume of 140mL / g when expanded at 250°C, 210mL / g when expanded at 300°C, and 265mL...

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PUM

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Abstract

A production of low-temperature expandable graphite is disclosed. It is carried out by using perchloric acid-phosphoric acid mixed acid solution with mass ratio HCLO4:H3PO4=1:0.02-3, oxidizing natural flake graphite under solid strong oxidant potassium permanganate, and producing low-temperature expandable graphite. Natural flake graphite: perchloric acid-phosphoric acid mixed acid solution: solid strong oxidant potassium: organic acid=1:0.5-8:0.02-0.6:0-1.5. , the mass concentration of HCLO4 and H3PO4 in mixed acid is 58%-82%. It achieves low cost.

Description

1. Technical Field [0001] The invention relates to a preparation method of carbon material-expandable graphite, in particular to a preparation method of low-temperature expandable graphite. 2. Background technology [0002] Expandable graphite refers to graphite oxide formed by oxidizing and intercalating natural flake graphite to form interlayer intercalation compounds between its layers. When it is heated under certain temperature conditions, it can rapidly expand hundreds of times. Expandable graphite has a wide range of applications. For example, it can be used as a flame retardant when its volume expands rapidly when subjected to high heat; when it is subjected to high heat, its volume expands greatly and bursts to form a large number of interference smoke screens, which can be used as a multi-wavelength transmission Smoke agent use, etc. It can also be made into expanded graphite after being heated and expanded, and then compressed into flexible graphite sealing products fo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B31/04
Inventor 应宗荣林雪梅
Owner NANJING UNIV OF SCI & TECH
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