New sealing materials and packing effect of deep hole pre-splitting blasting in coal seam roofs
Aiming at solving the problems of heavy labor intensity,slow filling progress and high transportation cost of deep hole filling with traditional clay stemming during blasting operation,a new packing material for convenient transportation,fast consolidation and high sealing efficiency was expected.We used the sealing performance of clay stemming as a comparison target to study the basic property and sealing efficiency of a novel material.The results revealed that the setting time of the new packing material will be longer with the increase of water-cement ratio,and the maximum heat release temperature of the material hydration reaction is 65.6℃,which is safe for the hole plugging.The uniaxial compressive strength of the new packing material will reduce while the water-cement ratio increasing,and that will increase while materials aging,and its strength is much higher than that of clay stemming material.Under static load compression,the filling capacity of the novel packing and clay stemming materials will both increase exponentially with the filling length increase,but the filling effect of the new packing material is much better than that of clay stemming.The increasing speed of filling capacity with the packing length increase far outweighs that with aging.The research results can provide a theoretical reference for the high-efficiency sealing process of large and deep holes.
roof of coal seamdeep holepresplitting blastinghole sealing materialeffect of packing
NETL
NSTL
万方数据
