金川铜尾渣粉对充填体强度的影响

Effect of Jinchuan copper slag on filling body strength

将金川还原提铁后的铜尾渣粉(JCCS)分别作为胶凝材料和代替棒磨砂作为充填骨料,采用正交胶砂试验,进行活性及力学强度试验研究。利用X线衍射(XRD)和扫描电镜(SEM)分析JCCS试件的水化产物及微观结构。研究结果表明:JCCS是一种惰性固体废弃物,无潜在活性;JCCS作为骨料代替棒磨砂,对早期强度不利,但有利于提高后期强度,当JCCS质量分数达30%时,3 d和7 d强度下降为0 MPa,28 d平均强度可提高24.8%;JCCS试件的水化产物主要为C-S-H凝胶和钙矾石(AFt),两者交错黏结共同构成力学强度。添加复配早强剂,能提高JCCS充填体早期强度。JCCS能代替20%的棒磨砂用于井下充填,可节约充填成本11.6元/m3。

Orthogonal experiments were conducted using Jinchuan copper slag（JCCS）, the industrial waste after extracting iron as backfill cementitious materials and aggregate substituting for rod milling sands to study the activity and mechanical strength of JCCS. Hydration products and microstructures of the samples were analyzed by XRD and SEM. The results show that JCCS is an inert solid waste without potential activity. It is negative for early strength, but good for long-term strength when JCCS replaces rod milling sands. Compressive strengths of 3 d and 7 d decrease to 0 MPa when the JCCS mass fraction is up to 30%, and the average strength of 28 d can improve 24.8%. The hydration products of the JCCS sample are mainly C-S-H gel and AFt which bond together and form the strength. Early strength agents can improve the strength of JCCS samples. JCCS can replace 20% of rod milling sands be used in backfill, and save backfill cost RMB11.6 yuan/m^3.