Study on the hydration and gelling properties of copper tailings activated by thermal-mechanical synergy

Copper tailings are fine sand particles that remain after the beneficiation processes in copper mines. The accumulation of these tailings can lead to various environmental issues. The crystallinity of copper tailings is high, but the activity is low. Many researchers have explored the use of activated copper tailings as auxiliary materials for concrete and other materials, but the utilization rate is relatively low. This paper stimulates the activity of copper tailings through thermal-mechanical synergy activation, analyzes the hydration and cementation performance of activated copper tailings, and analyzes the hydration reaction effect based on compressive strength, particle size distribution, and microstructure changes of mineral phase composition. X-ray Diffractometer（XRD）, Fourier Transform Infrared Spectroscopy（FT-IR）, and Scanning Electron Microscopy（SEM） are employed to further analyze the gelling properties of copper tailings. The results show that the mechanical properties of copper tailings activated by thermal-mechanical synergy have been greatly improved. Specifically, the activity of copper tailings increases from 5.60% to 89.91% with the conditions of 600 ℃ and the mechanical ball milling time of 80 minutes, resulting in a compressive strength of 10.87 MPa. The XRD and FT-IR analysis reveal the presence of hydrated C—S—H, N—A—S—H, ettringite, and other cementitious substances in various forms such as flocculation, cotton ball, and short rod. The study provides valuable theoretical support for the further utilization of copper tailings.