Coarse tailings backfill design considerations and optimisation: a case study from Malanjkhand Copper Project

Authors: Lee, C; Badavath, S; Chaudhary, D Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2655_25

Cite As:
Lee, C, Badavath, S & Chaudhary, D 2026, 'Coarse tailings backfill design considerations and optimisation: a case study from Malanjkhand Copper Project', in AB Fourie, M Horta, M Oliveira & S Wilson (eds), Paste 2026: Proceedings of the 28th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 1-14, https://doi.org/10.36487/ACG_repo/2655_25



Abstract:
Hindustan Copper’s Malanjkhand Project is a 2.5 Mtpa copper operation that has transitioned from open pit to underground sublevel open stoping with paste backfill. The existing mill produces a very coarse tailings material with an average D20 of 13 µm and periods of even coarser grind. Laboratory testing indicated that the resulting paste backfill was not stable, exhibited high friction factors and was prone to pipeline plugging. A study was performed which evaluated options to improve the pipeline transportation properties of the tailings such as regrinding or harvesting legacy fine tailings from an existing tailings management facility. However, due to the close proximity of iron blast furnace operations and the low local cost of ground blast furnace slag (GBFS), the study selected the option of adding a 90/10 binder blend of GBFS/cement with an overall concentration of 10% by weight of binder. The GBFS provides the additional fines needed to improve the paste stability as well as providing the majority of the cementitious material to give the backfill its strength. The plant was commissioned in 2025 and optimisation efforts are underway to minimise binder consumption while meeting the target strength requirements and rheological constraints of pipeline transport. This paper discusses the process of selecting the preferred option, commissioning experience and optimisation efforts.

Keywords: paste backfill, coarse tailings, rheology, optimisation

References: