Application Of Self-swelling Stem In Open-pit Blasting

Blasting is one of the basic work of open-pit mining,which affects the efficiency of subsequent procedures such as shovel,loading,and transportation.Filling the blasthole is an important means to ensure the blasting effect.At present,due to the lack of suitable filling materials,the filling of open-air blastholes generally uses a single rock powder or coarse aggregate for filling,which results in tedious filling work,low blasting energy utilization rate and high blasting pollution.Based on the blasthole packing mechanism,a self-expanding packing body is designed in this paper.The indoor and field blasting experimental research on the performance of the self-expanding packing body is carried out as follows:(1)Aiming at the packing requirements of high airtightness and high friction resistance for open-air packing,the self-expanding packing body was developed.Based on the selfexpanding packing material,the structure of the self-expanding packing body was designed,and the laboratory preparation of the self-expanding packing body was completed.The basic performance parameters such as water absorption,hydration reaction temperature and expansion rate of the self-expanding packing body were tested.(2)Based on the self-expanding stuffing body,carry out experiments on the packing performance of the self-expanding stuffing body based on factors such as the difference in pore diameter,water hole environment,immersion water temperature and ambient temperature.(3)Aiming at the problem that the low temperature will delay the hydration reaction of the self-expanding packer,experiments were carried out to optimize the expansion time of the self-expanding packer,as well as experiments on the effect of the internal and end face thermal conduction methods on the reaction time.(4)Relying on a quarry,an open-air single-hole and explosive area experiment of a selfexpanding packer to fill the blasthole was conducted.The effect of the self-expanding packer on the transmission equipment was studied,and the self-expanding packer was used to fill the blast hole.Blasting effect.The self-expanding packing body developed in this paper can produce a friction force of 34.98kN in 30min,which is equivalent to about 3m of loose material packing.The selfexpanding packing body relies on the expansion and squeezing effect of the self-expanding packing body to make it contact the wall of the blast hole while filling the depression.And cracks to achieve fast and efficient plugging of the blasthole,increase the action time of the high-temperature explosive gas in the blasthole,improve the explosive blasting energy utilization rate,improve the blasting effect,and achieve the purpose of effective plugging.