电厂灰渣制备井下膏体充填材料试验研究

为了探究不同灰渣对充填体强度的影响，将流化床底渣、流化床飞灰和粉煤灰按不同比例混合，作为充填骨料，普通硅酸盐水泥作为胶结材料，加水制备膏体材料，进行流动度测试和抗压强度试验。结果表明：（1）流化床灰渣中含有部分胶凝成分，粉煤灰具有减水作用和一定的火山灰活性，二者均为良好的井下充填材料。（2）当膏体材料含水率超过其饱和含水率时，膏体流动性会大幅提高，充填材料发生离析、脱水，导致充填体强度降低。（3）当流化床底渣、飞灰和粉煤灰配比为6∶2∶1，水泥含量为10%，料浆浓度为73%时，坍落度为20 cm，充填体28 d强度可达3.3 MPa。此配比在满足料浆流动度和充填体强度要求的同时，使充填成本大幅降低。（4）将上述配比作为对照组，进行级配优化试验，将原状底渣进行破碎后作为细骨料，以不同比例取代原状底渣。当底渣破碎至粒径小于等于5 mm，取代率为10%~15%时，充填体7 d强度达到2.4 MPa，28 d强度可达3.5 MPa，充填体强度明显提高。该研究结果为电厂灰渣在黄金矿山充填工程中的应用提供了参考和借鉴。

Experimental Study on Preparation of Paste Filling Materials from Power Plant Ash

The application of power plant ash to mine goaf filling can enrich aggregate source and consume a large amount of solid waste，which has important social benefits.Power plant ash mainly refers to the ash produced by coal-fired power generation，which is a kind of bulk solid waste with the characteristics of large discharge and low utilization rate.The properties of ash produced by different types of power plants are very different，but they generally have certain pozzolanic activity and gelation characteristics，so they are good filling materials.In order to explore the influence of different ash residues on the strength of the filling body，fluidized bed bottom slag，fluidized bed fly ash and fly ash were mixed with different ratios as filling aggregate，ordinary silicate cement was used as cementation material，and add water to prepare paste material，then fluidity test and compressive strength test were carried out.The results show that：（1）The fluidized bed ash contains some cementation components，the fly ash has the water-reduction effect and the pozzolanic activity，both of which are good downhole filling materials.（2）When the moisture content of paste material exceeds its critical moisture content，the fluidity will be greatly improved，which will also lead to segregation and dehydration of the filling material，then reduce the strength of the filling body.（3） When the ratio of fluidized bed bottom slag，fluidized bed fly ash and fly ash is 6∶2∶1，cement content is 10%，the slurry concentration is 73%，the slump is 20 cm，and the 28 d strength of the filling body can reach 3.3 MPa.This ratio not only meets the requirements of slurry fluidity and backfill strength，but also greatly reduces the filling cost.（4）Taking the above ratio as the control group，the grading optimization experiment was carried out.The undisturbed bottom slag was broken，then the fine particles with different particle sizes and proportions were used as fine aggregate to replace the undisturbed bottom slag.When the particle size of the broken bottom slag less than or equal to 5 mm and the replacement rate is 10%~15%，the strength of filling body reaches 2.4 MPa on 7 day and 3.5 MPa on 28 day，and the strength is significantly improved.The experimental study of the paste filling material prepared from the ash residue of power plant with a specific ratio provides data support and theoretical basis for engineering application，which is of economic value and environmental protection significance.