Experimental study of the effect of seawater and temperature on the corrosion resistance of cement composites with the addition of copper post-flotation waste

The presented results of the study concern the determination of corrosion resistance of cement composites with the copper post-flotation waste (PFW) as a cement substitute in the amounts of 2.5%, 5.0%, 7.5%, and 10%, exposed to seawater, depending on the temperature (10°C and 20°C). To better evaluate and understand the compressive strength, the hydration products of the cement composites were analyzed after exposure to seawater at 28 and 360 days by TGA and XRD methods. The cement composites incorporating test material exhibited corrosion resistance in seawater, with samples containing 5 wt% PFW achieved the highest compressive strength of 69.7 MPa (at 20°C) and 68.9 MPa (at 10°C) after 360 days of immersion in seawater. The obtained results were higher by 27.9% and 3.6% compared to the control samples. The tests (360 days) showed the possibility of using copper as a post-flotation waste additive in up to 5% of cement mass without significant changes to cement composites' mechanical and chemical properties. The research results indicate the potential possibility of waste used in construction, which would not only allow for a significant reduction in the production costs of cement, including a reduction in CO₂ emissions, but above all, would eliminate the risk of its negative impact on the natural environment.