Tailings Cemented Paste Rackfill Creep Properties And The Prediction Of Surface Movement In Backfill Site

Cemented tailings filling is considered to be one of the best ways to achieve no waste mining at present,which can control the surface subsidence,improve the ore recovery rate and promote the mine environmental protection.It is a difficult problem in the safe disposal of tailings in the process of nonferrous metal mineral processing at present.In the process of containing sulfur tailings as aggregate to do the underground.cementation filling treatment.Metal sulfide minerals will produce oxidation reaction to produce sulfate,and cause long-term erosion of the filling body,which affect the engineering stability of the filling body.Therefore,both from the economic point of view or from the security point of view,It is urgent to deeply study the creep mechanics of the filling body.Through literature review and field investigation,this paper determines the six mechanical indexes of the filling body,and makes a selection of them.The influence of different sulfur content and curing age on the creep properties of tailsand filling body was analyzed in the optimum ratio,and the creep damage constitutive model was deduced.The physical and mechanical parameters of a metal ore are measured,the FLAC3D is redeveloped,and the numerical simulation is carried out in different working conditions,and the law of surface movement is predictedThe main research work and achievements are as follows:The slurry concentration is 74%,cement sand ratio is 1:6,fly ash is 20%.The oxidative acid production of sulfide will weaken the strength of the filling body and have the damaging effect on the creep characteristics of tailings filling.The creep process consists of four stages,namely,the instantaneous elastic stage、the decay creep stage,the steady creep stage and the accelerated creep stage.The cementitious material has a hardening effect,and the sulphate has a softening effect,which verify the correctness of the constitutive equation for the damage of the tailings tailings.The surface subsidence value is the highest under high sulfur condition,and the surface subsidence value is almost the same in low sulfur and medium sulfur condition.