关键词: 充填开采, 全尾砂充填材料, 强度, 正交试验

Abstract: Aiming at the problems of large deformation and low strength of the filling material of a gold mine,the strength and shrinkage performance of the total tailings filler were improved by adding compound admixture,and the optimal ratio of admixture was obtained. The composite materials selected in the experiment included slag fiber,fly ash,quicklime,cement and tailing sand. The optimal proportion of additives was determined by orthogonal test. The microscopic mechanism of the modified materials was studied by means of mineral diffraction and scanning electron microscopy. The results show that the best filling material ratio is 1. 6% fiber content,0. 5% fly ash content,10. 0% quick lime content and 20. 0% cement content. The flexural strength and compressive strength of the modified packing are increased by 3. 8 and 1. 6 times respectively,and the shrinkage rate is reduced by 120%. XRD patterns show that different mineral compositions change with increasing curing age,which reflects the whole process of hydration reaction. The SEM scanning images clearly showed that the pores of the filler were full of cement and quicklime particles,and the slag fiber adsorbed a large number of solution gel products,which explained the reason for the improvement of strength and shrinkage properties from the perspective of microscopic mechanism,indicating that the increase in strength and shrinkage properties was due to the addition of additives to change the original microstructure and the formation of gelling products.

Key words: filling mining,unclassified tailings filling material,strength,orthogonal test