高掺量气化渣膏体充填材料强度性能研究

Study on strength properties of paste filling material with high content of gasified slag

针对目前矿井采空区充填成本高、煤-电-化工业产生的大量以气化渣为主的煤基固废处理难的矛盾,以宁夏鸳鸯湖电厂产出的气化渣为研究对象,探究高掺量气化渣膏体充填材料的强度性能。研究以气化渣为骨料,水泥为胶凝剂,前期通过单因素试验确定了气化渣在干料中的掺量、骨胶比、料浆浓度等3种因素的合理范围,利用响应面法设计了17组中心组合试验,探究了3因素以及3因素间的交互作用对膏体充填材料强度的影响规律,建立了3因素与7 d、14 d养护龄期时充填材料强度间的函数关系,优化了膏体充填材料的配比方案。结果表明:骨胶比是影响7 d、14 d强度的首要因素,骨胶比和料浆浓度交互对7 d强度影响最大,气化渣在干料中的掺量和骨胶比交互对14 d强度影响最大。研究得到最优配比参数为:气化渣在干料中的掺量为49.282%,骨胶比为4.554∶1,料浆浓度为81.056%。

In view of the contradiction between the high filling cost of the mine goaf and the difficulty in the treatment of large quantities of coal based solid waste mainly composed of gasification slag generated by the coal electricity chemical industry,the strength performance of paste filling materials with high content of gasification slag was explored by taking the gasification slag produced by Ningxia Yuanyanghu Power Plant as the research object.Gasification slag was used as aggregate and cement was used as gelling agent.In the early stage,the reasonable range of three factors,namely,the amount of gasification slag in the dry material,the aggregate-cement ratio,and the slurry concentration,were determined through single factor tests.Using response surface method,17 groups of central combination tests were designed to explore the influence of the three factors and the interaction between the three factors on the strength of paste filling materials.The functional relationship between the the three factors and the strength of filling materials at the curing age of 7 and 14 days was established,and the proportion scheme of paste filling materials was optimized.The results show that the aggregate-cement ratio is the primary factor affecting the 7 d and 14 d strength.The interaction of aggregate-cement ratio and slurry concentration has the largest impact on the 7 d strength,and the interaction of the amount of gasification slag in the dry material and aggregate-cement ratio has the largest impact on the 14 d strength.The optimum ratio parameters were obtained as follows:the content of gasified slag in dry material is 49.282%,the aggregate-cement ratio is 4.554∶1,and the slurry concentration is 81.056%.