Mgumbwa, J & Nester, T 2014, 'Paste improvement at La Mancha’s Frog’s Leg underground mine', 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. 281-294, https://doi.org/10.36487/ACG_rep/1404_22_Mgumbwa (https://papers.acg.uwa.edu.au/p/1404_22_Mgumbwa/) Abstract: La Mancha Resources Australia Pty Ltd’s Frog’s Leg Gold Mine is located approximately 20 km west of Kalgoorlie in Western Australia. The mine utilises long hole open stoping and cemented paste fill, to achieve full extraction of the orebody. The combined effects of high fines contents in the supplied reclaimed tailings, and very high water salinity, hampers the strength development and curing times of the paste fill, despite the high binder dosages. Given a decreasing gold price and a high operating cost environment, the need to identify areas where productivity and efficiency improvements can be made is paramount. Predominately due to the large volumes involved, paste backfill constitutes one of the largest costs to the underground operation, and therefore an area where even minor efficiency improvements can have a significant positive effect on mining costs. One of several improvement projects undertaken was to evaluate two paste additives, namely MM701 (supplied by BASF) and Acti-Gel® (supplied by Active Minerals) and their impact on paste flowability, compressive strengths, curing time and binder dosage rates.