Weatherwax, TW, Brosko, W, Evans, R & Champa, J 2010, 'Role of admixtures in the optimisation of paste backfill systems', in R Jewell & AB Fourie (eds), Paste 2010: Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 137-146, https://doi.org/10.36487/ACG_rep/1063_12_Weatherwax (https://papers.acg.uwa.edu.au/p/1063_12_Weatherwax/) Abstract: Barrick and BASF are working to improve the performance of Barrickā€™s paste backfill operations through the use of admixtures. Both super-plasticisers and rheology modifying agents have been trialled and have shown positive results in terms of enhanced rheology and ultimate strength gain. Multiple trials ranging in scope from bench scale trials to a two month production trial have been conducted, which has allowed for a better understanding of both the technical and economic benefits that can be obtained by adding admixtures to paste fill. The trials to date have shown good results in allowing paste plants to achieve pumping distances and ultimate strengths that would be difficult or impossible to achieve without the admixture. Results for trials examining the use of admixtures under typical operating circumstances have been less clearly beneficial. While the admixtures that have been trialled were concrete admixtures it is hoped to develop a backfill specific admixture, which will provide the desired results in terms of strength and rheology with better economics.