58 / 2023-05-15 22:30:16

Study on the electrical potential during low-temperature oxidation of coal

electrical potential,spontaneous combustion,low-temperature oxidation,coal,coal temperature

Coal spontaneous combustion significantly threatens the mine safety. Accurate prediction and early warning are the key factors and prerequisites for preventing the self-heating of coal. Surface potential (SP) , an indicator for characterizing the rock materials’ fracture status,  was measured when the coal samples were subjected to low-temperature oxidation using a heating pad. The results show that surface potential was generated instantaneously when the coal was subjected to external heat. When the sample’s temperature increased, the SP value increased accordingly. While the temperature was held constantly, the SP came to a peak and started decreasing right after. Different types of coal were tested within the same experimental setup and as the coal’s propensity to spontaneous combustion increased, the SP value increased under the same condition. The correlation coefficient between the coal temperature and the SP value was also calculated. Based on the surface potential response from different types of coal, the self-heating temperature and risk of coal during low-temperature oxidation may be determined from the surface potential.