Evaluation of Mount Heaney leads slag to produce a cemented backfill

Mount Heaney is a lead slag stockpile located between Mount Isa Copper Operations (MICO) and George Fisher Mine (GFM) in Mount Isa, Queensland, Australia. This slag pile contains relatively high zinc grades but due to its size is readily available for use as a partial fill material. As a result possible backfill cost savings exist; a study was conducted to determine the viability of using the slag as an additive for cemented paste backfill at GFM. Two different methods for using the slag were examined in this paper. The first involved using it as a cement replacement in a blended binder. The second involved blending the slag with the tailings to create a cemented aggregate fill. This paper will present the process by which each method was conducted, and will present and discuss the results of the rheological and strength laboratory testing that was conducted on the materials. The paper will then present a financial analysis for the preferred method and will summarize what future work is still required. It is hoped that the results and analysis presented in this paper will give other mining operations a methodology to maximize their waste product usage.