Method for determining coal ignitability

Abstract

A measuring method of coal self combustion tendency is suitable for the qualitative analysis and classification of the self combustion tendency of coal bed in a coal mine. The method includes the following steps: through testing the oxygen concentration at the air outlet of a coal sample tank when coal sample reaches the set temperature, the oxidation rate of coal at a low-temperature oxidation stage is judged; through testing cross-point temperature, the oxidation rate at an accelerated oxidation stage is judged; then, combined calculation is carried out through adopting the two parameters to obtain the value of coal self combustion tendency determination index; moreover, the smaller the value is, the easier the self combustion becomes and vice versa. Therefore, the method effectively solves the problem of comprehensive reflection of the characteristics of low-temperature slow oxidation stage and accelerated oxidation stage of coal self combustion, and increases the measuring accuracy of coal self combustion tendency; moreover, with simple and reliable operation and unified classification standard, the entire measuring process only needs to test two parameters and can be completed within 3 hours to 4 hours. In addition, with a simple method, convenient operation, time saving and labor saving and accurate testing result, the invention has wide practicality in the related field.

Description

technical field [0001] The invention relates to a method for measuring the spontaneous combustion tendency of coal, which is suitable for the qualitative and classification of the spontaneous combustion tendency of coal seams in coal mines. Background technique [0002] Coal spontaneous combustion is one of the major disasters faced by coal mine safety production in my country. Coal seams prone to spontaneous combustion account for 79.93% of the total number of mined coal seams in China, and mines with thick coal seams in key state-owned coal mines basically have the problem of spontaneous combustion. The determination of coal spontaneous combustion tendency is the prerequisite for effective fire prevention and extinguishing work in mines. At present, the methods for measuring coal spontaneous combustion tendency: foreign countries mainly include adiabatic oxidation method (USA, Australia, etc.), high temperature activation energy method (Poland), intersection temperature me...

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Problems solved by technology

The adiabatic oxidation method used abroad has a long test period (often more than ten hours or even dozens of hours), and the test conditions are harsh; ) under the condition of oxidative self-heating, which cannot reflect the whole oxidative self-ignition process including the low-temperature oxidation stage

The methods used in China have the following shortcomings: first, the physical adsorption of oxygen by coal is only related to the surface properties and pore structure of coal, and cannot reflect the comprehensive characteristics of coal spontaneous combustion low-temperature slow oxidation stage and accelerated oxidation; second, the coal at room temperature The amount of oxygen absorbed does not represent the amount of oxygen participating in the oxidation reaction. The amount of oxygen participating in the oxidation reaction mainly depends on the type and number of active groups in the coal structure; third, the classification standards are not uniform, and different combustible and ash-free volatile The classification standards are inconsistent, and the tendency test results will be seriously misjudged due to the fluctuation of the volatile content of the flammable ash-free base within the allowable error range of the critical value

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