A state-of-the-art review on delayed expansion of cemented paste backfill materials  

作　　者：Meng-Yuan Li Li-Jie Guo Yue Zhao Lei Zhang Kai Yang Xiao-Peng Peng Andrew Pan 

机构地区：[1]BGRIMM Technology Group,Beijing 100160,China [2]National Centre for International Research On Green Metal Mining,Beijing102628,China [3]Department of Civil and Mineral Engineering,University of Toronto,Toronto,ON M5S 1A4,Canada

出　　处：《Rare Metals》2024年第8期3475-3500,共26页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.52274122);the Research Fund of BGRIMM Technology Group (No.02-2136);the Youth Innovation Fund of BGRIMM Technology Group (Nos.04-2306,04-2342 and 04-2208)。

摘　　要：Utilizing delayed expansion cemented paste backfill materials(DECPB) in mine backfill operations offers an effective solution to the challenge of achieving proper contact between the in-situ cemented backfill mass and the roof in mined-out areas(backfill-roof contact).This article presents recent progress in both theoretical and experimental research concerning DECPB.The types and mechanisms of expansive additives,including expansive agents,foaming agents,and expansive mineral materials relevant to DECPB,are explained,along with their impact on the expansive properties and mechanical characteristics of DECPB.The composition,material characteristics,preparation methods,and controlled release mechanisms of microcapsules are analyzed.Two methods for measuring the volume change rate of paste backfill slurries are discussed.Research indicates that an appropriate content of expansive additives not only enhances the expansive properties of cemented paste backfill materials but also contributes to improving their mechanical properties.Chemical foaming agents and bentonite are found to be more suitable for preparing DECPB compared to expansive agents.The delayed expansion of cemented paste backfill material is influenced by microcapsules,with their wall materials,preparation parameters,and the alkaline slurry environment affecting their controlled release mechanism.Developing and optimizing precise measurement devices and methods forfor the volume change rate of cemented paste backfill materials is essential requirement for studying the performance of DECPB.Combining delayed expansion technology with retarding techniques in cemented paste backfill materials can provide a reliable solution for achieving proper backfill-roof contact in the future.

关 键 词：Paste backfill Delayed expansion Mining with backfill Expansive additives TAILINGS 

分 类 号：TD803[矿业工程—矿山开采]