Salter, R, Flemmer, A, Gelson, J & Martic, Z 2015, 'Chemical technology case study in cemented paste backfill – Newmont’s Tanami Gold Mine', in R Jewell & AB Fourie (eds), Proceedings of the 18th International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 371-382.
Cemented paste fill operations have been in operation for many years in Australia. In recent years, rapid advances have been made in chemical technologies improving mining backfill operations. BASF’s indepth analysis and laboratory work on both the physical and chemical parameters involved in backfill operations has been instrumental in re shaping this pathway. Many physical parameters can be improved via plant modifications; however, at significant expense to the mine. Even with peak plant performance, further optimisation can only be achieved in a cost-effective manner via improved chemistry. This is where chemical admixtures come into their own.
The feed to the backfill plant uses dry excavated tailings. The Tanami plant was unable to operate to the specified solids contents due to variations in chemistry, fineness and high clay content of the tailings, which in turn affected the desired throughput and strength consistency of the fill. Higher cement contents were also required to reliably maintain the desired strengths. The chemical solution proposed by BASF increased solids content, reduced friction and pressures in the pipelines, and maintained a more consistent paste throughput with consistent strengths.
This case study describes the processes employed by BASF for Newmont to identify and resolve issues encountered in the backfill operation at their Tanami Gold Mine. The case study discusses topics from initial sampling, analysis and lab testing to final onsite trials of the chemical admixture solution provided. The benefits to the mine are summarised in the paper.