Wei Zhen, Yang Ke, He Xiang, Zhang Jiqiang, Hu Guangcheng
State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, China.
Institute of Energy, Hefei Comprehensive National Science Center, Hefei 230031, China.
Materials (Basel). 2022 Aug 2;15(15):5318. doi: 10.3390/ma15155318.
The large production and low comprehensive utilization rate of solid waste from coal power base affects the efficient and coordinated development of regional resources and the ecological environment. In order to promote utilization of solid waste from coal power base, coal gangue, fly ash, and gasification slag are mixed as raw materials to prepare filling materials, and a study on the evolution law of the mechanical properties of coal-based solid waste filling body is systematically carried out. After clarifying the physical and chemical properties of the filling materials, the Box-Behnken experimental design method was used to study the effects of slurry mass fraction, coal gangue, fly ash, and gasification slag on the strength of the filling body based on the response surface-satisfaction function coupling theory. Furthermore, a multivariate nonlinear regression model was constructed for the strength of the filling body at different maintenance ages. Based on the analysis of variance (ANOVA) and the response surface function, the impact mechanism of influencing factors and their interaction on the strength of filler were revealed. The results show that the strength of the filler is affected by single factors and interactions between factors. The interaction of slurry mass fraction and gangue dosing has a significant effect on the strength of the filler in the early stage; the interaction of fly ash and gangue dosing has a significant effect on the strength of the filler in the middle stage; the interaction of slurry mass fraction and gasification slag dosing has a significant effect on the strength of the filler in the final stage. The mixed filling materials significantly affect the strength of the filler as the maintenance time is extended. The mixed filling materials are extensively interlaced with the hydration products, calcium alumina, and calcium silicate hydrate (C-S-H) gel, forming a stable three-dimensional spatial support system as the maintenance time increases. The best ratio to meet the requirements of mine filling slurry pipeline transportation and filling body strength was selected using the regression model and the proposed economic function of filling material.
煤电基地固体废弃物产量大、综合利用率低，影响区域资源高效协同发展和生态环境。为促进煤电基地固体废弃物利用，将煤矸石、粉煤灰、气化渣混合作为原料制备充填材料，并系统开展了煤基固体废弃物充填体力学性能演化规律研究。在明确充填材料物理化学性质后，基于响应面-满意度函数耦合理论，采用Box-Behnken试验设计方法研究了料浆质量分数、煤矸石、粉煤灰、气化渣对充填体强度的影响。此外，针对不同养护龄期的充填体强度构建了多元非线性回归模型。基于方差分析（ANOVA）和响应面函数，揭示了影响因素及其交互作用对充填体强度的作用机理。结果表明，充填体强度受单因素及因素间交互作用影响。料浆质量分数与矸石掺量的交互作用在早期对充填体强度影响显著；粉煤灰与矸石掺量的交互作用在中期对充填体强度影响显著；料浆质量分数与气化渣掺量的交互作用在后期对充填体强度影响显著。随着养护时间延长，混合充填材料对充填体强度影响显著。混合充填材料与水化产物、钙矾石、硅酸钙水化物（C-S-H）凝胶广泛交织，随着养护时间增加形成稳定的三维空间支撑体系。利用回归模型和提出的充填材料经济函数，选取了满足矿井充填料浆管道输送和充填体强度要求的最佳配比。
