红土膏体充填材料及其物理特性试验研究

Experimental study on red clay paste backfilling material and its physical characteristics

充填开采是实现矿山安全绿色开采的重要途径,但要求充填材料来源广泛、成本低,且必须能满足充填工艺要求,为开发新型膏体充填材料,以广西百色州景煤矿为工程背景,使用取材方便、成本较低的红土代替粉煤灰,将其与煤矸石,胶结材料混合制成红土膏体充填材料。通过试验测量不同固体材料质量比,不同干料质量分数的红土膏体充填材料的坍落度、扩展度、泌水率,并使用RYL-600剪切流变仪进行单轴压缩试验,测其抗压强度与弹性模量,进而分析红土膏体充填材料的强度特性,以及材料配比与干料质量分数对其性能的影响规律。研究结果表明:同等条件下与传统粉煤灰型充填材料相比,红土型充填材料强度差别不大,并且红土具有成本低、取材方便以及对环境无污染等优势;干料质量分数对充填体强度影响最大,当为80%时性能最优;随着红土掺量增加,充填体强度会降低,数据显示,红土与水泥质量比在1∶1、1∶2、2∶1时均满足充填要求,矸石、红土、水泥质量比为6∶2∶1时,充填材料既符合膏体充填工艺要求,又能减少充填成本。

Backfilling mining is an important way to realize safe,green mining in mines.However,backfilling materials require a wide range of sources,low cost,and must meet the backfilling effect.Therefore,many researchers and technicians have devoted a lot of energy to research and develop new paste backfilling materials.Based on the engineering background of Guangxi’s Baise Zhoujing Coal Mining,this paper considers replacing fly ash with laterite,which is convenient and low-cost,and mixes it with coal gangue and cementing materi⁃als to make laterite paste backfilling materials.By measuring the slump,expansion and bleeding rate of red clay paste backfilling materials with different proportions and different slurry concentrations,and using the RYL-600 shear rheometer to perform uniaxial compression tests,the compressive strength and Modulus of elasticity,analysis of the strength characteristics of red clay paste backfilling materials,and the influence of material ratio and slurry concentration on its performance.From the test data,it is found that compared with the tradi⁃tional fly ash type backfilling material under the same conditions,the laterite type backfilling material has little difference in strength,and the laterite type has the advantages of low cost,convenient material acquisition and no pollution to the environment.The dry material mass fraction has the greatest impact on the strength of the backfilling,and the performance is optimal when it is 80%;as the content of red clay increases,the strength of the backfilling will decrease,the data shows that the mass ratio of laterite to cement meets the backfilling re⁃quirements at 1∶1,1∶2,2∶1,and the ratio of gangue∶laterite∶cement=6∶2∶1,the backfilling material not only meets the re⁃quirements of the paste backfilling process,but also reduces the backfilling cost.