高硫尾砂充填体强度特性及外加剂应用研究

Study on Strength Characteristics and Admixture Application of High Sulfur Tailings Backfill

为解决某铅锌矿细粒级、高含硫尾砂充填时强度偏低、后期强度劣化的问题,通过对充填材料进行分析,采用粗骨料与全尾砂作为充填骨料进行充填,开展了充填材料配比、强度特性室内试验研究,并根据高硫尾砂特性研发了CKY充填外加剂。结果表明:全尾砂与粗骨料配比为8∶2和7∶3时,充填料浆保水性均较好,质量浓度为76%~78%的料浆具有较好的和易性,不发生沉降或有少部分尾砂沉降,适合充填;尾砂含硫量达32%,充填体试块在60 d、90 d龄期时出现不同程度劣化,加入了2%添加剂后,全尾砂∶粗骨料为8∶2的充填体前、后期强度增长明显,全尾砂∶粗骨料为7∶3的充填体前期强度虽未增长,但后期强度增长明显,且未出现强度劣化现象,表明CKY添加剂对于维持充填体强度的效果较好。

In order to solve the problems of low strength and late strength deterioration of fine-grained and high-sulfur tailings filling in a lead-zinc mine,analysis was carried out on filling materials,and the coarse aggregate and full tailings were used as filling aggregates.The indoor experimental studies on the proportion and strength characteristics of filling materials were carried out.According to the characteristics of high sulfur tailings,CKY filling admixture was developed.The results are drawn as follows.When the ratio of total tailings to coarse aggregate is 8:2 and 7:3,the water retention of filling slurry is good.The slurry with mass concentration of 76%~78%has good workability,no settlement or a small part of tailings settlement,which is suitable for filling.The sulfur content of tailings reaches 32%,and the filling body test block deteriorates to varying degrees at 60 d and 90 d.After adding 2%admixture,the early and late strengths of the filling body increase significantly when the ratio of total tailings to coarse aggregate is 8:2.When the ratio of total tailings to coarse aggregate is 7:3,the early strength of the flling body doesn't increase,but the later strength increase significantly,without strength deterioration.The results show that CKY additive has a good effect on maintaining the strength of filling body.