低品质矿渣协同粉煤灰制备充填胶结料及参数优化研究

Preparation of filling binder from low-quality slag synergy fly ash and optimization of slurry parameters

针对尾砂充填成本高、固结效果差的问题,本文采用低品质矿渣、粉煤灰等活性材料制备充填胶结料,并对料浆参数进行优化,以期在满足充填要求的前提下,降低充填成本。首先对实验材料进行物化特性分析,采用正交实验和极差分析确定胶结料配比,并分析其水化机理;其次以料浆配比实验分析了胶砂比、质量浓度对充填体强度、料浆流动性和稳定性的影响;最后采用多属性决策模型对料浆参数进行优化,获得了满足矿山要求的料浆优化参数。研究结果表明:低品质矿渣复合胶结料配比为熟料8%、脱硫石膏14%、粉煤灰10%、矿渣68%,熟料水化促进矿渣和粉煤灰水解,并发生水化生成大量凝胶,在脱硫石膏作用下生成少量钙矾石,随着水化产物增多,强度逐渐增加;充填体强度均随着料浆质量浓度和胶砂比的提高不同程度增大,塌落度和泌水率均随着浓度和胶砂比的提高逐渐减小;充填料浆优化参数为胶砂比1∶4,质量浓度70%。通过实验验证,充填料将满足矿山要求。

In order to solve the problems of high filling cost and poor consolidation effect of tailings,this paper uses low-quality slag,fly ash and other active materials to prepare filling cement and optimizes the slurry parameters,so as to meet the filling requirements and reduce the filling cost.Firstly,the physical and chemical characteristics of the test materials are analysed,and the cement ratio is determined by orthogonal test and range analysis,and the hydration mechanism is analysed.Then,the influence of cement sand ratio and mass concentration on the strength of the filling body,the fluidity and stability of the slurry are analysed by the slurry ratio test.Finally,the multi-attribute decision-making model is used to optimize the slurry parameters,and the slurry optimization parameters that meet the requirements of the mine are obtained.The research results show that the proportion of low-quality slag composite cement are clinker 8%,desulfurized gypsum 14%,fly ash 10%,slag 68%.The hydration of clinker promotes the hydrolysis of slag and fly ash,and a large amount of gel is generated by hydration.A small amount of ettringite is generated under the action of desulfurized gypsum,and the strength gradually increases with the increase of hydration products;the strength of filling body increases with the increase of slurry concentration and cement sand ratio,and the slump and bleeding rate decrease with the increase of slurry concentration and cement sand ratio;the optimum parameters of the filling slurry are the ratio of cement to sand is 1∶4,and the mass concentration is 70%.Through test verification,the filling material will meet the requirements of the mine.