Mine waste represents a growing global challenge due to increasing volumes, aging tailings storage facilities, escalating management costs, and stringent environmental regulations. This study addresses the dual environmental and economic burden of mining waste in Australia by proposing a sustainable valorisation pathway for its utilisation in high-strength construction materials. A circular economy framework is introduced to convert mining tailings, traditionally considered a liability, into valuable resources. The research focuses on the recovery of critical minerals (eg Ni, Mn, and rare earth elements) from sulfide tailings, followed by the utilisation of the residual aluminosilicate matrix for the synthesis of high-performance geopolymer composites. Selective leaching of nickel was systematically investigated and optimised. Under the optimal conditions of 5 per cent HNO3 and 10 per cent H2O2, a liquid-to-solid ratio of 5, a leaching duration of 30 mins, and a temperature of 60°C, a nickel extraction efficiency of 95 per cent was achieved, with minimal co-leaching of aluminium (~10 per cent), the primary impurity. The post-leaching residue, enriched in aluminium and silicon, was effectively repurposed as a precursor for geopolymer production. The resulting geopolymer composites demonstrated a ~20 per cent enhancement in compressive strength and a ~47 per cent reduction in total porosity compared to conventional ordinary Portland cement. Overall, the proposed approach offers a cost-effective, environmentally sustainable strategy for reprocessing sulfide tailings with relatively mild reagents. This work highlights a significant advancement in the circular utilisation of mining waste, contributing to resource recovery, waste minimisation, and the development of next-generation construction materials.