Pneumoconiosis has become one of the biggest threats to the occupational health and life safety of mining workers in China. The number of pneumoconiosis cases has continued to rise in recent years. The main task of occupational health development is to study the pathogenesis of pneumoconiosis and to develop mine dust prevention and control technology. Therefore, this paper summarizes the research progress of coal worker pneumoconiosis and dust prevention and control in mines. Firstly, the research progress of coal worker pneumoconiosis is analyzed from the aspects of pathogenesis, animal model and pathological changes of coal worker pneumoconiosis. Then, the existing basic theory and technology of dust prevention are described, including ventilation and dust removal, spray and dust suppression, and chemical dust suppression methods. Finally, based on the dust removal theory of wet shotcrete, the progress of shotcrete dust control technology and equipment used for shotcrete is summarized from the aspects of shotcrete technology process and shotcrete materials. At the same time, in view of the shortcomings of the existing research, the next research prospect is given in the pathogenesis of pneumoconiosis, intelligent dust prevention, jet spraying dust removal and so on. This paper provides theoretical support for realizing the separate source and efficient treatment of mine dust control and helps to improve the clean production level of mine, control and prevent pneumoconiosis.

High temperature is recognized as one of the extreme environments in the application of shotcrete which significantly deteriorate the performance of shotcrete. This paper reviews the mechanical properties and microstructure of shotcrete under high temperature. First of all, this paper reviews the cause of formation of high ground temperature. Based on these causes, the author establishes a heat transfer model with a spiral shape by introducing a multidimensional morphological formula into the heat conduction process. Then, the paper reviews the influence of high temperature on the mechanical and micro properties of shotcrete, the cooling technology under high temperature, and the optimization research technology of shotcrete. The author discusses the influence of high temperature on the thermal parameters and the deformation of shotcrete from the perspective of thermodynamics. Multiple studies have shown that the irregular movement and disorderly overlapping of molecules in the shotcrete caused by the high temperature environment result in the premature termination of the hydration reaction of cement in shotcrete. Finally, the author suggests the challenges of high-temperature shotcrete in term of the process structure, performance optimization, and application in special engineering fields. The research in this paper intends to give guidance to those conducting shotcrete research under high temperature, and to promote the further development of shotcrete technology.

In recent years, with the rapid development of the coal-mining industry, the output of gangue has increased at a faster pace, while its utilization remains relatively low. The accumulation of a large amount of gangue has brought about a large environmental problem. In order to improve the utilization rate of waste gangue, and to solve the secondary environmental problems caused by gangue pollution, this paper conducted research on an economic and environmentally friendly gangue-based self-compacting concrete. This study designed aggregate industrial-analysis experiments to analyze the moisture content of the gangue and limestone, finding that the moisture content of gangue is 39% higher than that of limestone. By orthogonal experimental methods, the study investigated the fluidity, compressive strength, splitting strength and abrasion resistance of self-compacting gangue concrete. It was concluded that the optimal replacement rate of gangue for coarse aggregate is around 30%, the optimal replacement rate of fly ash for cement is around 30%, the optimal addition of polycarboxylate superplasticizer is 0.5% of the mass of cementitious materials, and the optimal rate of shear steel fibers is around 1% of the concrete capacity. In addition, this paper investigated the interfacial transition zone (ITZ) of the aggregate–cement slurry and found that the ITZ of gangue aggregate and cement mortar is more likely to generate AFT crystals, which will contribute more to the improvement of the strength of concrete in the early stage. In addition, a field-effect analysis was carried out in this study, and it found that gangue-based self-compacting concrete, as an environmentally friendly material, can basically meet the design requirements of C30 paving concrete.