Experimental study on resistivity response characteristics of loaded coal during nitrogen injection

Abstract

In order to explore the evolution of coal cracks during nitrogen injection, the resistivity response tests of coal during nitrogen injection were carried out. The research shows that during the nitrogen injection process, the resistivity of the coal remains basically unchanged at first, then increases slowly, and increases suddenly and stabilizes at about 1.2 finally. The nitrogen adsorption of coal leads to a decrease in resistivity, and the higher the nitrogen pressure is, the greater the decrease in resistivity will be. The development of fissures in the coal will affect the conduction channel, resulting in an increase in resistivity. In the process of nitrogen injection, the resistivity change of the loaded coal is the result of the combined effect of the nitrogen adsorption of coal and the expansion of the fissures of the coal.