Present Geothermal Field and Roadway Heat Damage Characteristics in Zhujidong Coal Mine Area of Huainan City, Anhui Province, China

Abstract

With the normalization of deep mining, the problem of mine thermal damage has been widely concerned. In this paper, 64 logging temperature data of surface boreholes of Zhujidong coalfield in Huainan City, Anhui Province, China, were summarized and sorted. The temperature data of 12 measuring points at the current main working level of −906 m and −965 m were measured. The ground temperature conditions of the vertical direction, horizontal direction, and main coal seam floor in the coalfield were analyzed. The characteristics of the present geothermal field and roadway heat damage, and its influencing factors were discussed. The results showed that the geothermal gradients of this area are between 1.7 ℃/hm and 3.6 ℃/hm, and the average geothermal gradient is 2.607 ℃/hm. It shows the transmission of warming in the vertical direction and horizontal direction shows the ground temperature lowering from south to north, east to west. The geothermal field in this area is mainly affected by the geological structure, and the thermal physical properties of rocks, magmatic rocks and groundwater activities also have a certain effect. At present, most of the main work level has reached the first heat hazard area, and some are in the second heat hazard area, according to Chinese regulations. The working face temperature is keeping above 28 7 ℃ and the relative humidity is being maintained above 70% for a long time. The problem of heat damage is extremely serious. It is suggested to construct the thermal environment control measures combining active and passive ways.