Waste glass powder as a partial replacement of binder in improving the performance of cemented paste backfill

Abstract

This study investigates the potential of Waste Glass Powder (WGP) as a sustainable replacement material in Cemented Paste Backfill (CPB) for metal mining operations. The primary objective is to explore WGP's capacity to reduce operational costs and environmental impacts associated with CPB, particularly by addressing the significant cement consumption that drives up costs. The research focuses on evaluating WGP as a cost-effective binder, examining its effects when partially replacing cement in CPB with three average particle sizes: 75 µm, 90 µm, and 125 µm. Laboratory tests were conducted on CPB samples incorporating varying WGP dosages of 10%, 20%, 30%, and 40% by weight of cement. The performance of these samples was assessed through a series of tests, including X-ray fluorescence (XRF), moisture content analysis, rheology testing, and mechanical testing. These tests aimed to evaluate the influence of WGP particle size on pozzolanic activity, compressive strength, and overall stability of the CPB. The results demonstrate that partial replacement of cement with WGP can significantly enhance CPB performance. Notably, the particle size of WGP plays a significant role in influencing pozzolanic activity, compressive strength, and mitigating expansion due to alkali-silica reactions (ASR). XRF analysis revealed a high silica content of approximately 76.4% in the WGP, further supporting its reactivity. For instance, at a 10% WGP dosage with a particle size of 125 µm and a curing age of 28 days, the compressive strength of CPB samples increased by an average of 13.8% compared to the reference sample. These findings highlight WGP's potential as a sustainable and cost-effective binder material for CPB in mining operations.