Effects of water content, water type and temperature on the rheological behaviour of slag-cement and fly ash-cement paste backfill  

作　　者：Yue Zhao Abbas Taheri Murat Karakus Zhongwei Chen An Deng 

机构地区：[1]School of Civil,Environmental and Mining Engineering,The University of Adelaide,Adelaide 5005,Australia [2]School of Mechanical and Mining Engineering,The University of Queensland,Brisbane 4072,Australia

出　　处：《International Journal of Mining Science and Technology》2020年第3期271-278,共8页矿业科学技术学报（英文版）

基　　金：This research was partially funded by Mining Education Australia(MEA)and OZ Minerals,Australia;their support is gratefully acknowledged.

摘　　要：The pumping ability and placement performance of fresh cemented paste backfill(CPB) in underground mined cavities depend on its rheological properties. Hence, it is crucial to understand the rheology of fresh CPB slurry, which is related to CPB mixture design and the temperature underground. This paper presented an experimental study investigating the effects of binder type, content, water chemical properties and content, and temperature, on the rheological properties of CPB material prepared using the tailings of a copper mine in South Australia. Portland cement(PC), a newly released commercially manufactured cement called Minecem(MC) and fly ash(FA) were used as the binders added to the mine tailing materials. Various amounts of two different water types were added to the mixtures in the preparation of backfill material slurry. Six different temperatures ranging from 5 to 60 °C were to investigate the effect of temperature on CPB rheology. Overall, the increasing water content and decreasing temperature lead to lower yield stress. Based on the results obtained from the rheological properties of CPB slurry, it was found that at room temperature(25 °C), with regards to the unconfined compressive strength(UCS) performance, the replacement of 4% PC mixed CPB(28 days UCS 425 k Pa) to 3% MC mixed CPB(28 days UCS 519 k Pa), reduced the slurry yield stress from 210.7 to 178.5 Pa. The results also showed that the chemical composition of water affects the yield stress of CPB slurry and that MC mitigates the negative effect of mine-processed water(MW) and thus lead to improve the rheological properties of the slurry. However, the results suggested that the rheological properties of a mixture using MC is very sensitive to the water volume and temperature change. Therefore, using MC in backfill requires better quality control in slump mixing.

关 键 词：Cemented paste backfill Minecem RHEOLOGY Yield stress Fly ash Portland cement 

分 类 号：TQ172.1[化学工程—水泥工业]