掺塑性膨胀剂的全尾砂胶结充填体体积变化率试验研究及机理分析  

Experimental study and mechanism analysis on the volume change rate of cemented unclassified tailings backfill with plastic expansive agent

作　　者：张敏哲 王贻明[1] 吴爱祥[1] 王剑 王志凯 刘树龙 ZHANG Minzhe;WANG Yiming;WU Aixiang;WANG Jian;WANG Zhikai;LIU Shulong(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;MCC Tongsin Resources Ltd.,Beijing 100028,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]中冶集团铜锌有限公司,北京100028

出　　处：《采矿与岩层控制工程学报》2025年第1期167-178,共12页Journal of Mining and Strata Control Engineering

基　　金：国家自然科学基金资助项目(52374111,52130404)。

摘　　要：为解决矿山充填采场接顶率偏低和接顶效果较差的问题,采用响应面法,研究了在充填料浆中掺加塑性膨胀剂时,料浆质量分数、胶固粉掺量和塑性膨胀剂掺量对全尾砂胶结充填体体积变化率的影响规律;并利用X射线衍射(XRD)和扫描电镜(SEM),分析了塑性膨胀剂对充填体的作用机理;通过现场工业试验,验证了掺塑性膨胀剂充填体的膨胀接顶效果。研究结果表明:塑性膨胀剂掺量对充填体体积变化率的影响程度最大,料浆质量分数次之,胶固粉掺量最小;不掺塑性膨胀剂的充填体在所有龄期均是沉缩的;塑性膨胀剂掺量存在一个临界值,使充填体由沉缩特性转变为膨胀特性;塑性膨胀剂可使充填体在塑性阶段产生膨胀,补偿充填体早期沉缩;膨胀变形主要发生在养护龄期3 d以内, 3 d以后趋于稳定;掺加塑性膨胀剂未改变充填体水化产物种类,但能使充填体内部生成大量的膨胀性矿物钙矾石,导致内部结构疏松而引起膨胀;现场实测值与试验实测值较吻合,不掺塑性膨胀剂的充填体体积变化率为–3.45%,塑性膨胀剂掺量为6×10^(–4)的充填体体积变化率为3.04%。研究成果可为矿山充填接顶技术及应用提供参考。For the challenges of low roof-contacted rates and poor filling performance in mine backfill stopes,a plastic expansive agent(PEA)into the filling slurry was introduced to enhance roof-contacting efficiency and stability.The response surface methodology(RSM)was employed to investigate the effects of slurry mass concentration,cementitious powder content,and PEA content on the volume change rate of cemented unclassified tailings backfill(CUTB).The mechanism of PEA on CUTB was further analyzed using X-ray diffraction(XRD)and scanning electron microscopy(SEM),and its expansive roof-contacting effects were validated through field industrial testing.The results indicate that PEA content has the most significant influence on the volume change rate of CUTB,followed by slurry mass concentration,with cementitious powder content having the least impact.CUTB without PEA exhibited consistent shrinkage across all curing ages.However,a critical PEA content threshold was identified,beyond which the behavior of CUTB shifted from shrinkage to expansion.Expansion deformation was primarily observed within the first three days of curing and stabilized thereafter.This expansion,induced by PEA during the plastic stage,effectively compensates for early-stage shrinkage.Microscopic analysis revealed that PEA does not alter the types of hydration products in CUTB,but promotes the formation of expansive mineral ettringite,resulting in a looser internal structure and volume expansion.Field measurements corroborated the experimental findings:CUTB without PEA exhibited a volume change rate of−3.45%,while CUTB with a PEA content of 6×10^(−4) achieved a positive volume change rate of 3.04%.These findings provide theoretical insights and practical recommendations for improving roof-contacting filling technologies in mining applications.

关 键 词：充填接顶 塑性膨胀剂 响应面法 体积变化率 微观结构 

分 类 号：TD853[矿业工程—金属矿开采]