Cihangir, F, Erçıkdı, B, Turan, A, Kesimal, A, Deveci, H, Yazıcı, M & Karaoğlu, K 2011, 'Utilisation of sodium silicate activated blast furnace slag as an alternative binder in paste backfill of high-sulphide mill tailings', in R Jewell & AB Fourie (eds), Paste 2011: Proceedings of the 14th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 465-475, https://doi.org/10.36487/ACG_rep/1104_40_Cihangir
(https://papers.acg.uwa.edu.au/p/1104_40_Cihangir/)
Abstract: Paste backfill (PB) is an engineered mixture of mill tailings, binders and water. Ordinary Portland cement (OPC) is extensively used as a binder in cemented paste backfill (CPB) operations. However, it is known that such calcium-rich binders have a particularly low resistance to acid and sulphate attack. In this study, activated blast furnace slag with sodium silicate (AAS-SS) was tested as an alternative binder for CPB of high-sulphide mill tailings. A strength loss in CPB samples prepared from OPC was observed in the long term at binder dosages of 5–7 wt%. Those prepared from AAS-SS were found to have produced durable samples over 360 days of curing. In addition, CPB samples with AAS-SS binder produced approximately 3.5–4.1 times higher 360 day strengths than those with OPC at binder dosages of 5–7 wt%. The unconfined compressive strength (UCS) values were supported with acid and sulphate monitoring and scanning electron microscope (SEM) studies performed on OPC and AAS-SS samples after 360 days of curing. As an indication of pyrite oxidation, sulphate ions and acid were generated during the hydration and hardening process, and secondary mineral phases such as gypsum were observed within all samples.