锡冶炼渣-全尾砂胶结充填体强度特性研究

Study on strength characteristics of tin smelting slag-unclassified tailings cemented paste backfill

充填体材料的选择以及强度特性的研究有助于解决矿山生产安全、环境破坏、充填成本等问题。为了将冶炼生产中的固体废渣二次利用,并与矿山尾砂胶结后将其运用于回填矿山采空区,选用锡冶炼渣-全尾砂作为充填试验材料,通过室内实验、逐步回归分析以及双因素交互作用分析的方法研究了不同锡冶炼渣掺量、质量浓度、灰砂比、养护龄期下充填体抗压强度的特性。实验结果表明:其他条件固定不变,充填体的单轴抗压强度随养护龄期的增加呈递增规律;同质量浓度及灰砂比条件下,充填体单轴抗压强度随锡冶炼渣掺量的增加呈递减的趋势;28 d养护龄期,质量浓度78%,灰砂比1∶4,掺入30%锡冶炼渣,充填体抗压强度降至7.04 MPa,与未掺锡冶炼渣强度值9.5 MPa相比,降幅为25.9%。低灰砂比、低质量浓度,掺入同量锡冶炼渣对充填体试件抗压强度影响较小。经逐步回归分析得出充填体单轴抗压强度回归方程以及影响充填体强度大小的因素排序。锡冶炼渣掺量与灰砂比交互作用对充填体的强度影响较为显著。

The selection of cemented paste backfill(CPB)materials and the study on strength characteristics are helpful to solve the problems of mining safety,environmental damage and backfilling cost.In order to reuse the solid waste residue in smelting and cement it with tailings and apply it to backfill mine goafs,tin smelting slag-total tailings were selected as the CPB material,and the characteristics of different tin smelting slag content,mass concentration,cement-to-tailings ratio,and unconfined compressive strength(UCS)of CPB specimens under different curing periods were studied by indoor experiment,stepwise regression analysis and two-factor interaction analysis.The experimental results show that the other conditions are fixed,and the UCS of the CPB increases with the increase of curing age periods.Under the conditions of mass concentration and cement-to-tailings ratio,the UCS of the CPB decreased with the increase of tin smelting slag content.During the 28 d curing period,the UCS of cement-to-tailings ratio 1∶4 with a mass concentration 78%,the compressive strength was 7.04 MPa,which was 25.9%lower than that of smelting slag without tin smelting slag of 9.5 MPa.Low cement-to-tailings ratio,low mass concentration,and the addition of the same amount of tin smelting slag have little effect on the UCS of the CPB.Through stepwise regression analysis,the UCS regression equation of the CPB and the ranking of factors affecting the UCS of CPB were obtained.The interaction between the smelting slag content and the cement-to-tailings ratio has a significant effect on the strength of the CPB.