黄土沟壑矿区高浓度自流充填技术研究

High Concentration Gravity Backfill Technology in the Loess Gully Region

本文对以粉煤灰为主料的高浓度自流充填技术进行介绍。实验室测定主料加辅料质量分数小于66%时,料浆的流动性较好且能实现两小时不凝固,膨胀率控制在3%~10%,泌水率低于1%,充填体成型龄期达90 d时的单轴抗压强度在4 MPa以上,满足充填开采的要求。在此基础上,设计山西吕梁某矿高浓度自流充填方案及参数,并进行现场应用。结果表明:充填工作面地表最大下沉量稳定在160 mm左右;重金属监测结果显示该充填材料不会造成地下水源污染,同时减轻了粉煤灰地表外排对环境的影响;经计算该矿4#煤层充填开采吨煤利润约261.3元,经济效益显著,为其他黄土沟壑地区煤矿的充填开采提供了有益借鉴。

This article introduces the high-concentration gravity backfill technology with fly ash as the main material.According to laboratory testing,when the concentration is less than 66%,the slurry has good fluidity without solidification for two hours,with the expansion rate ranging from 3%to 10%and the bleeding rate less than 1%.When the molding age of the filling body reaches 90 days,the uniaxial compressive strength is above 4 MPa,which meets the requirements of backfill mining.A high-concentration gravity filling scheme and parameters were designed and applied on site for some mine in Lvliang,Shanxi province.The results show that the maximum surface subsidence is stable at about 160 mm.Heavy metal monitoring results show that the filling material does not cause groundwater pollution but reduces the impact of the fly ash on the environment.By calculation,the profit of the backfill mining is about 261.3 yuan per ton in the mine,which has significant economic benefits and could provide a useful reference for the filling mining in other loess gully areas.