极细全尾砂胶结充填参数优化的试验研究

Study on Parameters Optimization of Cemented Filling Test with Ultrafine Full Tailings

针对极细全尾砂胶结充填的充填体强度低、胶凝材料消耗量大等问题,以某矿山为实例,通过细粒全尾砂性能评价、自然沉降试验、塌落度试验、配比强度试验和自流输送试验及计算和分析,获得了最佳的充填技术参数。试验结果表明:全尾砂浆沉降24h后其最大浓度为73.4%,仅靠自然沉降无法满足矿山连续充填作业的要求。当全尾砂浓度为78%以上时,难于实现自流输送。为全尾砂浆浓度为74%~76%、料浆流量为150m3/h、管道内径为150mm时,管内料浆流速为2.36m/s,管道输送阻力为2.1kPa/m~4.4kPa/m,可实现自流输送的充填倍线为4~11。当全尾砂浆浓度为76%、灰砂比1∶4~1∶8时,充填试块60d的强度为1.78 MPa~3.62MPa,可满足矿山采空区充填的强度要求。

Aiming at the problems of low strength of backfill and large consumption of cementitious materials in cemented filling with ultrafine full tailings,taking a mine as an example,the best filling technical parameters were obtained through performance evaluation of fine full tailings,natural settlement test,slump test,proportioning strength test,gravity transportation test,as well as calculation and analysis.The test results show that,the maximum concentration of the full tailings slurry is 73.4%after 24hours of settlement,and the natural settlement can not meet the requirements of continuous filling operation.When the concentration of the full tailings is above 78%,it is difficult to realize gravity transportation.When the concentration of the full tailings is 74%~76%,the slurry flow rate is 150m3/h,and the inner diameter of the pipe is 150 mm,the slurry flow rate in the pipe is 2.36m/s,and the pipeline transportation resistance is 2.1kPa/m~4.4kPa/m,which can realize the gravity transportation under filling times line of 4~11.When the concentration of full tailings is 76%and the ratio of cement to sand is 1∶4~1∶8,the strength of backfill test block is 1.78MPa~3.62MPa in 60days,which can meet the strength requirements of goaf filling.