Adair, Revell, King, Keeney
Presented at the Preconcentration Digital Conference November 2020
ABSTRACT
Grade Engineering®, integrated across the mine value chain, has a pivotal role to play in achieving step change reductions in energy and water usage in mine operations. High levels of gangue rejection in the mine can significantly improve mineral head grades and overall productivity. A highly successful example is described at the Minera San Cristóbal (MSC) operation. The nature of the mineralisation in their “intrusive” ore domains in particular has facilitated high rejection rates (75 % of the mass), with significant upgrading of metal to the “accepts” streams (equating to a 2.6 times upgrade in the intrinsic Nett Smelter Return). Results from a series of production trials have confirmed these strong upgrades, resulting in the transformation of mineralised “marginal wastes” to high grade ore feedstocks.
If new approaches to more energy and water efficient comminution and separation technologies can also realise gangue rejection at finer sizes in the concentrator, then preconcentration strategies across the value chain also offer the promise of no wet tailings treatment facilities and greatly reduced volumes of waste streams.
This “No Tails” strategy is discussed, along with the integrated technologies needed to realise its effect. The work suggests a pathway and insights of a sustainable future for the Minerals Industry, unconstrained by Energy and Water, along with no requirement to produce problematic disposal streams. This strategy has the potential to significantly reposition the social, environmental, financial, and regulatory context of existing and new mining opportunities.
AUTHORS
B. Adair1, P. Revell1, D. King2 and L. Keeney1
1.CRC ORE, 1 Technology Court, Pullenvale, QLD 4069 Australia.
2.Minera San Cristóbal, Calacoto calle 15, Torre Ketal Floor 5, La Paz, Bolivia.
Keywords
Grade Engineering®
Gangue Rejection
ACKNOWLEDGEMENTS
This paper is dedicated to the memory of Dr. Dan Alexander. Dan was a friend to all the authors and an outstanding innovator. His recent passing has left the Industry bereft of one of its greatest advocates for a new sustainable future. His work and vision inspired us all. We can do no better than to work together to make his vision a reality.
Special thanks are due to the Minera San Cristóbal site staff who conducted the sampling and analysis of the various preconcentration evaluation regimes. This work was conducted under the auspices of the Australian Government Cooperative Research Centre (CRC) Program. CRC ORE is part of this Program, which is made possible through the investment and ongoing support of the Australian Government.
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