Physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal and method of preparing and using same

Patent metadata

Field	Value
Publication number	US-10648336-B2
Application number	US-201716090060-A
Country	US
Kind code	B2
Filing date	Dec 4, 2017
Priority date	Jun 16, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Disclosed is a physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, and methods of preparing and using the same. The composite inhibitor consists of a chelate and attapulgite, the chelate is generated by chelation of proanthocyanidin with calcium chloride. The composite inhibitor has moisture-absorbing and moisture-retaining effect, and can reduce water dissipation at low temperature. A stable oxide insulating layer such as MgO and Al2O3 insulating layer can be formed at high temperature, which can block a coal body from contacting with oxygen. In addition, the composite inhibitor can capture hydroxyl free radicals generated during the chain-cycle reaction and destroy peroxide free radicals, and can also interact with an active moiety in coal to form a stable structure such as ether linkage and hydrogen bonding, thereby achieving permanent inhibition of low-rank coal.

First claim

What is claimed is:

1. A physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, consisting of:
a chelate; and
an attapulgite,
wherein the chelate is generated by chelation of proanthocyanidin with calcium chloride.

2. The physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal according to claim 1 , wherein a mass ratio of proanthocyanidin to calcium chloride is between 1:6 and 1:8.

3. The physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal according to claim 2 , wherein the mass ratio of proanthocyanidin to calcium chloride is 1:7.

4. The physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal according to claim 1 , wherein a mass ratio of the chelate to the attapulgite is between 1:4 and 1:6.

5. The physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal according to claim 4 , wherein a mass ratio of the chelate to the attapulgite is 1:5.

6. A method for preparing a physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, the composite inhibitor consisting of a chelate and an attapulgite, wherein the method comprises:
dissolving and dispersing proanthocyanidin and calcium chloride in solvent water to form a first mixture;
stirring the first mixture for between 10 and 20 minutes to prepare a chelate solution;
adding attapulgite to the chelate solution to form a second mixture; and
stirring the second mixture for between 10 and 20 minutes to prepare a composite inhibitor solution.

7. A method for using a physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, the composite inhibitor consisting of a chelate and an attapulgite, the chelate generated by chelation of proanthocyanidin with calcium chloride, wherein the method comprises:
spraying a solution of the composite inhibitor to a residual coal region in an underground mined-out area to control spontaneous combustion of coal.

Assignees

• Univ China Mining

Inventors

• Zhong Xiaoxing
• Wang Feng
• Xia Chen
• Qin Botao

Classifications

• E21F5/06 Primary

  Fluids used for spraying · CPC title

• C09K21/02 Primary

  Inorganic materials · CPC title

• C09K21/06

  Organic materials · CPC title

• A62D1/0028

  Liquid extinguishing substances (A62D1/0092 takes precedence) · CPC title