Research and Application of Water Injection Technology for the Ultra-Thick Coal Seam in Fully Mechanized Working Face

In order to solve the technical problems such as difficulty in water injection and wettability of ultra-thick coal seam and poor control effect of dust and hydrogen sulfide of working face in the fully mechanized working face of Urumqi mining area, by means of theoretical analysis and test research, water injection with fan-shaped hole in ultra-thick coal seam, the hole sealing technology of upward water injection hole and water injection technology in advanced bearing pressure affected area was studied. A new technology of water injection with fan-shaped hole in advanced bearing pressure affected area of ultra-thick coal seam in fully mechanized working face was explored.The field application research showed that with this new technology, the total water content of coal increased from 2.7% to 5.8%, the increase was 3.1%.The quality concentration of respirable dust in coal cutting by coal mining machine fell to 7.3 mg/m³, and it fell to 10.7 mg/m³ when stents released coal. The dust removal efficiency reached 73.9% and 77.6% respectively, and the volume fraction of hydrogen sulfide decreased by 62.3% and 69.7% respectively, a good effect of governance has been achieved.