Optimisation of cemented aggregate backfill by addition of tailings

Optimisation of cemented aggregate backfill at New Luika Gold Mine

Authors: Salvoldi, BG; van der Spuy, B; Wilson, S

Presented at: Paste 2019

Paper Abstract

Cemented aggregate fill (CAF) and cemented rockfill (CRF) have successfully been used as a low-cost, highstrength backfill material in underground mines. The placement of the material and flowability generally limits the technology to low throughput application and smaller stope sizes if tight filling is required.

Optimisation of CAF/CRF flowability and strengths is most readily achieved by optimising the Fuller–Thompson gradation curve. CAF/CRF relies on the materials available on the mine site and the additional costs of borrow pits or additional crushing adds significant cost to a material that is usually chosen due to low cost.

This paper presents a case study of an optimisation of a CAF material by the addition of tailings in order to increase the paste fraction of the material. The main aim was to decrease the angle of repose to improve filling ability in addition to decreasing the required binder content.

Bruno Salvoldi

MSc Engineering (Civil), BSc Engineering (Civil)

Bruno is a director at our Cape Town office in South Africa. He leads the African mine backfill department and has completed projects from conceptual level through to detailed engineering, implementation, and commissioning.

Bruno’s postgraduate studies focussed on cement chemistry, and he now specialises in its application to backfill. He is part of the Paterson & Cooke Backfill Group and is involved globally with problematic backfill applications related to geochemistry and cement chemistry.