Study on Spontaneous Combustion Characteristics and Early Warning of Coal in a Deep Mine

Abstract

Due to high stress, high ground temperature, high moisture, and other factors in deep mines, the risk of coal spontaneous combustion (CSC) is enhanced, seriously affecting the safety of coal mining. To achieve early prediction of spontaneous combustion in the No. 3 coal seam at the Juye coalfield in the deep mine, this paper employs a temperature-programmed device to analyze the changing pattern of single-index gases and composite gas indices with temperature derived from the gas produced during csc. It also optimizes the index gas of coal sample spontaneous combustion. Simultaneously, the characteristics of coal temperature and a four-level warning indicator system for CSC are determined based on the analysis of indicator gas growth rate method, carbon-to-oxygen ratio, and the characteristics of the indicator gas. The composite index gases of the No. 3 coal seam in Juye coalfield are selected in the initial oxidation stage (Rco), accelerated oxidation stage (R1, G1), intense oxidation stage (R2, G1, G3), and oxidative decomposition stage (G3). This leads to the construction of a six-level warning system consisting of initial warning value, blue, yellow, orange, red, and black levels. Meanwhile, warning thresholds are also established.

Prediction of Coal Spontaneous Combustion Hazard Grades Based on Fuzzy Clustered Case-Based Reasoning

“…This algorithm introduces membership functions on the basis of the K-Means algorithm, which can better indicate the similarity between a sample and a certain cluster. The FCM objective function is shown in Equation (7).…”

“…In addition, coal spontaneous combustion also pollutes the soil and destroys the ecological environment [4][5][6]. In recent years, with the depletion of shallow mineral resources, more and more underground coal mine projects are going deeper underground at an unprecedented speed [7][8][9], causing coal spontaneous combustion to become a serious threat to many projects worldwide [10][11][12][13]. To prevent and control coal spontaneous combustion disasters, it is necessary to study the effective prediction of the coal spontaneous combustion method.…”

Prediction Model of Spontaneous Combustion of Lignite in Zhalainuoer Mining Area

“…Additionally, coal spontaneous combustion often leads to gas combustion, dust explosions, and other accidents, resulting in serious casualties. − The recent development of top coal caving technology and the increase in mining depth, accumulation of goaf coal, rise in temperature, and enhanced disturbances have exacerbated the problem of coal spontaneous combustion. − Predicting spontaneous combustion has become crucial for preventing and controlling coal spontaneous combustion fires and the associated likelihood of mine fires caused by coal spontaneous combustion. − Domestic and foreign scholars have conducted extensive research on systems for predicting coal spontaneous combustion. Coal temperature prediction in mines mainly relies on the concentration of single indicator gases released by coal spontaneous combustion, such as CO and C 2 H 4 . − Qiuge et al, by considering the Hequ open-pit mine as a case study, investigated the relationship between the tracking distance of internal dumping and the stability coefficient of the end slope and determined that this relationship conforms to a Boltzmann function. A reasonable tracking distance for internal dumping can enhance the end-slope stability.…”