Li, M, Gao, Q, Yang, Z & Wang, YT 2014, 'Experiment and analysis of hydration mechanisms on the new backfilling cementitious materials', in Y Potvin & T Grice (eds), Mine Fill 2014: Proceedings of the Eleventh International Symposium on Mining with Backfill, Australian Centre for Geomechanics, Perth, pp. 317-323, https://doi.org/10.36487/ACG_rep/1404_25_Li
(https://papers.acg.uwa.edu.au/p/1404_25_Li/)
Abstract: The experimental research discussed in this paper uses lime, gypsum, slag and other solid wastes to get new cementing materials that can replace the cement for Sijiaying iron ore tailings. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are employed to analyse the hydration mechanism of the activator in the new cementing materials, thereby determining the optimum ratio of activator. The research has shown that the new cementing materials’ strength can meet the requirements of staged backfill in Sijiaying when the solids concentration is 68%, mortar ratio is 1:8, lime is 3.5%, and gypsum is 16%. The results show that new cementitious sand has a more compact structure and coarse occurrence, when compared with cement mortar using SEM and XRD to observe and analyse the hydration products and microstructure. The hydration products are mainly AFt crystals and calcium silicate hydrate (C-S-H) gel, which greatly improves the novel cementitious sand strength. The new cementitious material has higher strength and lower cost than cement. It can effectively reduce the filling costs and improve mining efficiency in the low-grade iron deposit, which uses cut and fill mining method. The research of new cementitious material can lay the foundation for safe, efficient and environmentally sound development for a low-grade iron deposit.