Multi-objective optimization study on the mix design of coal-based green backfill materials considering the entire solidification process
SUN Yuehang
WU Shunchuan
CHENG Haiyong
JIANG Guanzhao
HE Yanduotai
LI Gaoqi
LI Zhaoju
Abstract：Coal-based green filling materials exhibit component diversity and multi-dimensional performance.Consider-ing the entire solidification process of the backfill and scientifically selecting a multi-component formulation is the primary concern for ensuring mine backfill quality.Accordingly,a Box-Behnken design(BBD)was first employed,with fly ash content(20%‒60%),slurry concentration(82%-86%),and gangue-to-binder ratio(3-7)as independent variables to construct response-surface models for the backfill's overall solidification performance(bleeding rate,setting time,and 28 d uniaxial compressive strength).Analysis of variance indicates that all regression coefficients in the models are statist-ically significant,prediction errors remain within 5%,and the models demonstrate very high fitting accuracy and reliable predictive capability.Fly ash content significantly influences bleeding rate and setting time;increasing fly ash improves slurry stability but delays setting.Slurry concentration is most sensitive to strength enhancement,with higher concentra-tions markedly boosting hydration efficiency.The gangue-to-binder ratio shows significant interactions with both concen-tration and fly ash content regarding strength and setting behavior.Next,the non-dominated sorting genetic algorithm NSGA-II was introduced for multi-objective optimization,yielding over 100 Pareto-optimal formulations.By treating suit-able setting time and controlled bleeding rate as basic constraints,and maximizing backfill strength and coal-based solid-waste utilization as objectives,three representative formulations meeting all constraints were selected,validating the prac-ticality of the NSGA-II approach for filling-material design.This BBD-NSGA-II-based method realizes scientific decision-making for multi-component coal-based green filling materials and can serve as a reference for similar formulation optim-ization.
Keywords：mine backfillingcoal-based solid-waste filling materialsmulti-objective optimizationbox-behnken designnon-dominated sorting genetic algorithm
Publication Date：2025-09-30
Online Publishing Date：2025-09-30(First online date of this platform, not the publication date of the document)
Pages：10( 30-39 )