高硫尾砂胶结充填体强度影响因素实验研究及应用

Experimental study and application of factors affecting the strength of high sulfur tailings cemented backfill

全尾砂用于井下充填在环保、安全、经济方面均具有显著优势,但有色矿山尾砂普遍含硫,过多的硫会劣化充填体长期强度.用新疆某铜矿高硫尾砂与戈壁料混合作充填骨料,通过全面实验法研究骨料硫含量、灰砂比、料浆浓度、养护龄期对充填体强度的影响,通过灰关联法分析各影响因素的主次排序.结果表明,硫含量低于11.72%时,充填体强度随硫含量、灰砂比、浓度增加呈线性增长,随养护龄期增加呈多项式函数增长,确定骨料中尾砂占比为30%.充填体强度影响因素的主次排序为灰砂比>养护龄期>浓度>硫含量(尾砂含量),建议矿山优化进路开采顺序以延长充填体养护时间,灰砂比由1∶4降为1∶6,可在满足强度和采充周期的同时降低充填成本.

Unclassified tailings are used for underground filling,which has significant advantages in environmental protection,safety and economy.However,tailings in nonferrous mines are generally sulfur-containing,and excessive sulfur degrades the long-term strength of the cemented backfill.The high-sulfur tailings from a copper mine in Xinjiang were mixed with Gobi materials as aggregates.The effects of sulfur content,lime-sand ratio,slurry concentration and curing age on the strength of the cemented backfill were studied by comprehensive experimental method.The primary and secondary ordering of each factor is analyzed by the grey relational method.The results show that when the sulfur content is lower than 11.72%,the strength of the filling body increases linearly with the increase of sulfur content,lime-sand ratio and concentration,and increases with the polynomial function with the increase of curing age.The proportion of tailings in the aggregate is determined to be 30%.The factors affecting the strength of the filling body are lime-sand ratio,curing age,concentration and sulfur content(tailing content),which are sorted from strong to weak.It is recommended to optimize the mining sequence of the roadway to increase the curing time of the backfill,and the lime-sand ratio should be decreased from 1∶4 to 1∶6,which can reduce the filling cost while satisfying the strength and mining&filling cycle.