Study on the performance of lightweight roadway wall thermal insulation coating containing EP-GHB mixed ceramsite

As the mining depth increases, the problem of high-temperature thermal damage mainly caused by heat dissipation of surrounding rock is becoming more and more obvious. It is very important to solve the environmental problem of mine heat damage to improve the efficiency of mineral resource exploitation and protect the physical and mental health of workers. One can apply thermal insulation coating on the walls of mine roadways as a means of implementing active heat insulation. In this paper, expanded perlite (EP) and glazed hollow bead (GHB) are used as the main thermal insulation materials, ceramsite and sand as aggregate, plus glass fiber and sodium dodecyl sulfate to develop a new lightweight composite thermal insulation coating through orthogonal experiment method. According to the plate heat flow meter method and mechanical test method, the thermal insulation and mechanical properties of EP-GHB mixed ceramsite coating were studied by making specimens with different parameter ratios, and according to the analysis of the experimental results, the optimal mix ratio of the coating was selected. In addition, Fluent numerical simulation software was used to establish the roadway model, and the thermal insulation effect of the coating in the roadway under different working conditions was studied. The results show that the thermal conductivity of the prepared composite thermal insulation coating material is only 8.5% of that of ordinary cement mortar, and the optimal thickness of adding thermal insulation coating is 0.2 m, which can reduce the outlet air temperature of the roadway with a length of 1000 m by 4.87 K at this thickness. The thermal insulation coating developed in this study has the advantages of simple technology and strong practicability, and has certain popularization and application value in mine heat damage control.