Research On Development Of New Cem-entitous Material And Pipe Transportatin Characteristic In Jinchuan Nickel Mine

The filling mining method not only has the significant advantages of high recoveryand low depletion rate, but also can effectively control the ground pressure and preventsurface subsidence. However,there exist many problems,such as filling materialshortage,high cost and low mining efficiency.Jinchuan nickel mine is ore deposit that is difficult to be mined with thecharacteristics of burying depth、fracture of surrounding rock and the height of crustalstress. Jinchuan nickel mine finally chose the downward slicing cemented backfill miningmethod through technology research and production practice. Filling materials mainly userod-mill tailings as filling aggregate and cement at present as cementitious material, adoptthe slurry whit high concentration and high sticky and ratio, the high cost of filling is rareat home and abroad, these lead enterprise to face tremendous economic pressure. To reducethe mining cost is the most urgent problem for Jinchuan nickel mine.Gansu province WengFu group produces and places a large amount of phosphorusgypsum waste each year. The storage of phosphorus gypsum waste residue not only takesup a large amount of land resources, but also is a serious to surface water, groud water andenvironmental safety. Therefore, the use of phosphorus gypsum and waste rock solid wasteand the development of low cost and high strength of new filling gel materials, not onlycan reduce the filling mining cost, but also realize the solid waste recycling use, also canrealize green no waste mining and protect mine environment, thus realizing the sustainabledevelopment of jinchuan company.According to a large of previous exploratory experiment, new cementitious materialuse phosphorus gypsum and slag as main raw material, and use quick lime,NaOHandglauber’s salt as compound early strength agent, the approximate rang of mixture ratio:quick lime is from4%to6%,NaOH is from2%to4%,glauber’s salt is from1.5%to2.5%，phosphorus gypsum is from30%to40%.Determined the optimal ratio of new cementitious material with rod-mill tailingsthough orthogonal test and range analysis, quick lime is from4%,NaOH is3%,glauber’ssalt is2%，phosphorus gypsum is from35%,slag is65.5%.When cement sand ratio is1:4 and concentration is80%，the filling body’s strength of3day is2.17MPa, the filling body’sstrength of7day is4.35MPa, the filling body’s strength of28day is8.97MPa, these meetthe requirements of filling body’s strength for Jinchuan nickel mine. The hydration reactionof new cementitious material mainly produces hydrated calcium silicate gel(C-S-H) andettringite(AFt) by the test of SEM.Carried out the experimental study on the rheological properties of new cementitiousmaterial slurry with rod-mill tailings. The test results show that the rheological propertiesof new cementitious material slurry don’t have differences in essence with cement slurry.Filling slurry based on new cementitious material still belongs to the Bingham body andmeets the liquidity requirements of gravity-flow transport for Jinchuan nickel mine.Using the numerical simulation of slurry transportation in pipeline by fluent softwarereveal the flow state of filling slurry transportation in pipeline, clearly observed thevelocity distribution and pressure distribution. Filling slurry based new cementitiousmaterial present state of laminar flow and have flow core (plug flow) in pipeline, gravityfilling can be achieved using existing gravity filling system in Jinchuan mining area.