金川下向分层充填法采矿大掺量粉煤灰应用研究

Application Study on Downward Sublevel Filling Method with High-volum Fly Ash in Jinchuan

金川镍矿采用下向进路胶结充填采矿法,要求3d和7d的充填体强度分别不小于1.5 MPa和2.5 MPa。由于掺加粉煤灰影响水泥胶结充填体的早期强度,因此目前粉煤灰掺量控制在10%以内。为了提高粉煤灰在金川矿山中的利用率,针对胶砂比为1∶4、料浆浓度为78%的充填浆体,开展了添加芒硝早强剂的早期强度试验。结果表明:当芒硝添加量为2.0%~2.5%时,掺加20%的粉煤灰,水泥胶结充填体的3d和7d强度分别达到2.5 MPa和3.0 MPa,完全满足金川矿山对充填体早期强度的要求,从而降低充填胶凝材料成本达到56元/t。该研究结果已在金川矿山应用,同时为减少废弃物排放和环境保护做出了有益探索。

Filling body strengths of 3days and 7days were required no less than 1.5 MPa and 2.5 MPa by downward route cemented filling method in Jinchuan nickel mine.Because of the influence of fly ash on early strength of cement filling body,the mixing amount of fly ash was controlled in10% at present.In order to improve the utilization of fly ash in Jinchuan mine,the early strength tests adding mirabilite were conducted for filling slurry with ratio of 1∶4and concentration of 78%.The results showed that with fly ash of20%,the filling body strengths of 3days and 7days could respectively reach 2.5MPa and 3.0MPa as the mirabilite of2.0%~2.5%,which totally met the requirements of early strength.Thereby the cost of filling material was reduced by56RMB/t.This research was used in Jinchuan mine,providing some beneficial explorations for waste discharge and environmental protection.