Water Injection and Dust Removal in High-Pressure and Low-Porosity Coal Seam

Abstract

Dust pollution is very serious in coal mining process, which is a great threat to the underground staff health and equipment and facilities safety. Coal seam water injection in mining process is an effective way to reduce coal mine dust concentration at the source. However, the effectiveness of water injection is limited in high-pressure and low-porosity coal seam. To improve the moisture content of coal seam, expand the wetting range and enhance the effect of dust reduction by water injection, the injectability and influencing factors of coal water injection are analyzed by numerical simulation method, and the sealing technology under high-pressure condition is studied. Then, according to the practical conditions of Tangkou coal mine, the parameters and process system of process system are designed, the effect of high-pressure water injection in coal seam was determined by testing water injection quantity, water increment and dust concentration. It is showed that the dust-removal rate of the high dust concentration operation such as falling coal and moving frame is 63.49% and 59.72%, the maximum dust-removal rate of multi-processes is 53%, which achieve a high level of application. The research results in this paper is of important theoretical and practical value to improve the water injection effect of high-pressure and low-porosity coal seam and improve the efficiency of dust removal in coal mining process.

Porosity and Fracture Changes of Bituminous Coal under Action of Dry–Wet Cycles in Acid Environment

“…Mine dust pollution is one of the common hazards in coal mining production and is the leading cause of pneumoconiosis in coal miners. − Coal seam water injection is a curative measure to reduce dust generation at the coal face from the source. − However, in practice, due to the presence of a large number of inorganic minerals in the coal, such as kaolinite, mullite, and so on, blocking the fractures and hindering the development of pore penetration seriously affect the transportation of water in the coal seam, resulting in the reduction of permeability of the coal seam. , For this reason, removing these minerals can effectively improve the permeability performance of the coal seam, while conventional water injection cannot dissolve them well. Therefore, the use of acidification technology to dissolve the inorganic minerals inside the coal prompts the emergence, expansion, and accumulation of coal pore fractures and ultimately the formation of macroscopic fractures and then improves the permeability performance of the coal, which has become an important research direction of coal seam water injection dust suppression. − …”