Reasonable Strength And Distribution Of Backfilling Material With Back-filling Mining Afterwards Open-stope

Back-filling mining method has obvious advantages in its high recovery and low dilution rate in the more valuable and difficult underground mining in metallic ore. It should be focused on how to be reasonable, efficient, economical and safe when we participate in the development and utilization of mineral resource, reducing ore dilution, improving the quality of the ore. Xinjiang copper-nickel mine is in construction, using Back-filling mining afterwards Level Large-Diameter and Long-Hole Open-Stope mining method at the test stope on the level of1200m. In order to guarantee the stability of roof and floor and the quality of ore pillars stopping as well as the conveying requirements of slurry, the paper carries out the reserch of filling body’s reasonable strength and also does filling body of the copper-nickel mine laboratory test.Because of application of cement filling method using classified the copper-nickel mine tailings, the paper does some relevant test to grading backfilling materials, including testing proportion, volume weight, porosity, grain diameter, chemical composition and slump test.And it aquires the curvilinear relation between mass concentration and slump.It still gains curvilinear relation under the circumstance of different filling materials, mass concentration, cement-sand ratio, cure age on filling body.It also gets the uniaxial compressive strength, tensile strength and physical and mechanical parameters. Collapsibility reduces along with the increase of mass concentration at the same situation of cement-sand ratio. However, when mass concentration grows and cement-sand ratio reduces, mass concentration influences less on strength. It concludes the strength will strengthen along with the increase of cement.To get the filling body’s reasonable strength in vertical distribution, it designs three plans according to actual situation of the mine. That’s to say, different level of filling materials has different cement-sand ratio. It adopts FLAC3d to analysis the course of stopping, which provides the reasonable parameters for the transport of filling materials on the1200m level. In the first step of the process of stopping, the roof and floor is safe as well as ore pillar. However in the second step of stopping and filling, local larger tensile stress occurs at the middle of filling body in plan1and2.It has the emergence of the plastic zone. Plan3is more reasonable because the strength of filling body of five levels in vertical height reaches the laboratory tensile and compressive experiment results.