| The Douzigou Iron Mine of Kuancheng Jianlong Mining Corporaton was an open-pit to underground mine built in 1992.At present,the+150m,+90m,+30m level section have been recovered.Current production capacity mainly depends on the roof and inter-column recovery of level+90m.During the mining process,Level+150m,+90m and+30m adopt short-hole shrinkage method for mining.In order to solve the problem of void and pillar recovery,roof blasting method is adopted causing surface subsidence and deposit loss and dilution.At the same time,the remaining storage capacity of the tailing damp is about 970,000 m3,and the service life is less than 3 years according to the current tailing emission speed.Therefore,the backfilling method can solve the problems of tailing replacement,resource recovery and ground pressure control.The depth of mining is growing deeper and deeper in order to build a green mine,extend the service life of the mine and maximize the economic benefits.Meanwhile,with the increase of the depth of the stope,the West Ventilation Shaft is in the range of rock movement area.With Level+90m using waste backfilling and Level+90m to Level-90m using cemented tailing backfilling,the stability of West Ventilation Shaft is analyzed whether it can be used anymore.According to the actual engineering situation,this paper proceeds cemented backfilling experiment indoor using tailings from Douzigou tailing damp.This paper studies on the influence of different factors,such as sand-cement ratio,material concentration,curing age and fly ash content,on the mechanics and flow properties of backfilling body,and studies on the sensitivity of different factors to the performance of backfilling body.The backfilling ration is determined according to similar mines and the interaction between the filling body and the surrounding rock.The mechanism of filling body to surrounding rock is expressed and backfilling method is of importance in the aspect of improving the stress distribution of the stope,maintaining the stability of the stope and controling the surface subsidence.This paper has optimizing the security pollar of West Ventilation shaft using critical medium column support theory,analyzed the theoretical mechanism and calcutated the movement angel of security pillar.This paper investigates and calculates the lateral pressure coefficient of the loose body and explores its effect on rock movement control.Using numerical simulation software FLAC3D,four orebody models such as I-1,I-2,I-3 and I-4 were established,while Level+90m using waste backfilling and Level+90m to Level-90m using cemented tailing backfilling.The stress distribution,the displacement of surrounding rock and the distribution of plastic zone during mining are studied.At the same time,the stability of the West ventilationg shaft and the surface subsidence were studied,the safety of the mining of Level-150m ore body was analyzed while mining. |
