Physical-chemical characterization and application research of copper tailings with wet-grinding activation for use as supplementary cementitious material

Based on the background that the severe environmental burden is caused by large amount of discharged wet copper tailings and the need to reduce carbon footprint in cement-related industry becomes increasingly urgent. This paper sought to evaluate the viability of applying wet grinding to treat wet copper tailings for preparing slurry supplementary cementitious material and to investigate the effects of wet-grinding copper tailings as partially replaced with cement on properties of cement paste. The experimental results revealed that the refinement of copper tailings was significantly facilitated by wet grinding and after 20 min of process, its median particle size decreased from 9.61 μm to 4.49 μm. The zeta potential of wet-grinding copper tailings was negative between −19.8 mV and −30.2 mV, and as the particle size reduced, the absolute value thereof increased. Furthermore, its slurry behaved like modified Bingham fluids. Wet-grinding copper tailings enhanced the early hydration of cement composite materials particularly within 12 h. When the incorporation amount of wet-grinding copper tailings was 20 %, the compressive strength at 28 d was 50.9 MPa, conspicuously higher than 44.2 MPa of the pure cement group at the same age. Wet grinding, as a novel and reliable method of treating wet copper tailings, had excellent environmental and economic benefits which was anticipated to be capable of resolving the dilemmas of the copper mining industry and the cement-related fields.