Dust Prevention with Deep Borehole Water Injection and Spalling Prevention with Grouting in Unstable Seam with Soft Roof, Coal and Floor
Abstract：In order to reduce the high coal dust density and serious coal wall spalling in the fully mechanized top coal caving mining face, according to the seam conditions with soft roof, coal and floor in Baiping Mine, the deep borehole water injection for dust control and the grouting for the coal wall reinforcement were conducted in the seam of the coal mining face. ZDY-3200 drilling rig was firstly applied to drill a water borehole with a depth of 60 - 80 m. ZBQ-6/2. 5 mode drilling rig was applied about 6 m near the water injection borehole to drill a grouting borehole on the coal wall with a depth of 9 m. The MRB125/31.5 mode water injection pump was apphed to the seam hy- draulic fracturing with a pressure of 12 - 14 MPa and after the seam fracturing, an intermittent water injection with a pressure of 5 - 8 MPa were repeatedly conducted. The site application effect showed that the technology applied could make the seam water content increased from 4% to 5% -6% and the average dust content in the air returning gateway was reduced from 269 mg/m^3 to 108 mg/m^3. The coal wall spalling scope of the coal mining face was reduced from 50% - 70% to 10% - 30% and the spalling problem was effectively con-trolled.
Keywords：seam with soft roofcoal and floordeep borehole water injectiondust reducespalling prevention and control
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 60-63 )