不同灰砂比条件下机制砂率对充填体强度影响试验研究

Experimental Study on Influence of Manufactured Sand Ratio to Backfill Strength with Variable Cement-Aggregate Ratios

为确定机制砂率达到40%左右时高浓度全尾砂胶结充填料浆的合理配合比,确定不同灰砂比条件下机制砂率对充填体强度的影响趋势,开展了以灰砂比、机制砂率为主要影响因素的充填体强度试验。试验表明,当机制砂率在30%~50%范围内时,灰砂比的变化对充填体强度发展速度的影响较小。当料浆浓度控制在80%或以上时,灰砂比1∶10,标准养护28 d后的充填体强度可达到4.5 MPa;灰砂比1∶6,养护14 d后的强度可以达到5.5 MPa以上。满足上述条件的充填料浆配比可用于云南某铅锌矿第一步骤矿房的充填。

In order to determine suitable mixing proportion of cemented tailing backfill with high-concentration under the condition of adding manufactured sand with a ratio about 40%to the weight of the tailing used,and to figure out the in⁃fluence trend of manufactured sand ratio on the backfill strength under different cement-aggregate ratios,a series of tests have been carried out to test backfill samples′strength while cement-aggregate ratio and manufactured sand ratio are chosen to be the main influencing factors.Test results show that when the ratio of manufactured sand is kept in the range of 30%~50%,the change of cement-aggregate ratio has little influence on the velocity of backfill strength development.When the concentration of cemented backfill slurry is well controlled at 80%or above,the strength of the backfill with a 1∶10 cementaggregate ratio can reach 4.5 MPa after 28 days of standard curing,and the strength can reach more than 5.5 MPa after 14 days of standard curing when the cement-aggregate ratio is 1∶6.Mixing proportions satisfying these conditions can be used for filling the first-phase stopes in one lead-zinc mine,Yunnan.