This project is now complete.
Project Leader: Daniel Southam (Curtin University of Technology)
Start Date: October 2006
The project investigated the potential for geopolymer-based backfill products to substitute Ordinary Portland Cement (OPC) in underground mine backfill at Mount Isa Mines. The suitability of using mine tailings and smelter slag as feedstock for geopolymers was investigated and geopolymer-based back fill products subsequently developed and tested, to demonstrate technical feasibility, economic viability and sustainability/greenhouse gas benefits.
A suite of potential binder feedstocks for use in tailings-based fills at Mount Isa Mines were obtained and characterised. Each of the wastes was tested in a neat binder and then target binders in a tailings-based fill, with each meeting the specified mechanical properties. This development illustrated the technical feasibility of waste-based binders to mine backfilling. An assessment of an example fill indicated that the replacement of OPC by geopolymer-based mine backfill systems could result in overall reductions in both energy usage and greenhouse gas emissions of the order of up to 25% and 25–60% respectively. For example, adoption of this technology at a 3Mt per annum backfill operation would equate to an annual reduction of the order of 100kt carbon dioxide.
The technical aspects of this study have concluded and the findings from it have formed the basis of a review of the commercial prospects for geopolymers in mine waste backfill, commissioned by CSRP.