Study on the activation mechanism and hydration properties of gold tailings activated by mechanical-chemical-thermal coupling

• Published in: Journal of Building Engineering 2022-05, Vol.48, p.104014, Article 104014
• Main Authors: Chen, Bingjiang, Pang, Lufeng, Zhou, Zaibo, Chang, Qingshan, Fu, Peng
• Format: Article
• Language: English
• Subjects: Activation mechanism; Gold tailings; Hydration properties; Mechanical-chemical-thermal coupling activation; Reactivity
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2022.104014

This paper mainly studies the activation mechanism and hydration properties of gold tailings. The reactivity of gold tailings under various activation methods was evaluated by the compressive strength test of cement mortar test blocks and Frattini tests. The activation mechanism of gold tailings and the hydration properties of the activated gold tailings were studied by XRD, FTIR, SEM, EDS, TG-DTG. The research results show that the 28-day compressive strength ratio of the mortar test block mixed with mechanical-chemical-thermal coupling activated gold tailings are 95.60%, and the consumption ratio of [CaO] in the slurry of coupled activated gold tailings is 60.76% at 15 days. After the gold tailings are mechanically ground, the crystallinity of the main mineral phase is reduced, but the pozzolanic reactivity is low, which mainly plays the filling effect of the micro-aggregate in the mortar test blocks. High-temperature calcination can remove the structural water in the muscovite to make it further decompose. In the presence of calcium oxide, high-temperature calcination is conducive to the depolymerization of siloxane radicals and improves the pozzolanic reactivity of the tailings. As the content of activated gold tailings increases, the content of calcium hydroxide in the hardened slurry decreases, and the content of C-S-H gel and calcium sulfoaluminate hydrate increases, proving that coupled activated gold tailings have pozzolanic reactivity. The gold tailings activated by mechano-chemical-thermal coupling can be used as supplementary cementitious materials for cement, and the practical application needs to be further studied. •The gold tailings were activated through mechanical-chemical-thermal coupling, and the compressive strength ratio (28 days) of the tailings mortar test block reached 95.60%.•The pozzolanic reactivity of the mechanically ground gold tailings is low, and it mainly plays the role of filling the micro-aggregate in the mortar test block.•In a high-temperature calcination environment, the structural water in the muscovite is removed, and the presence of calcium oxide is conducive to the depolymerization of siloxane radicals.•The compound activated gold tailings generate C-S-H gel with a low calcium-silicon atom ratio through the secondary hydration reaction, reduce the calcium hydroxide content, and increase the content of C-S-H gel and hydrated calcium sulfoaluminate.