Carbonate-activated binder modified by supplementary materials for mine backfill and the associated heavy metal immobilization effects

• Published in: International journal of minerals, metallurgy and materials Vol. 30; no. 8; pp. 1548 - 1559
• Main Authors: Dai, Xinghang, Gu, Xiaozhong, Zheng, Jingru, Zhao, Liang, Zhou, Le, Jiang, Haiqiang
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.08.2023; Springer Nature B.V; Liaoning Key Lab of Petro-chemical Special Building Materials,Fushun 113001,China%Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110819,China%Changchun Gold Research Institute Co.,Ltd.,Changchun 130012,China; School of Civil Engineering,Liaoning Petrochemical University,Fushun 113001,China
• Subjects: Activated carbon; Alkalinity; Backfill; Binders; Calorimetry; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Glass; Heavy metal content; Heavy metals; Immobilization; Magnesium oxide; Materials Science; Metallic Materials; Mine tailings; Mines; Mining industry; Natural Materials; Physical properties; Portland cement; Portland cements; Reaction kinetics; Resource utilization; Surfaces and Interfaces; Thermogravimetric analysis; Thin Films; Tribology; X-ray diffraction; environmentally friendly; sodium carbonate; tailings; heavy metals; cemented paste backfill
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-022-2540-2

Cemented paste backfill (CPB) is one of the effective methods for resource utilization of tailings, but the high cost of ordinary Portland cement (OPC) limits its utilization. Considering the poor performance of Na 2 CO 3 -activated binders, in this work, supplementary materials, including CaO, MgO, and calcined layered double hydroxide (CLDH), were used to modify their properties with the aim of finding an alternative binder to OPC. Isothermal calorimetry, X-ray diffraction, and thermogravimetric analyses were conducted to explore the reaction kinetics and phase assembles of the binder. The properties of the CPB samples, such as flowability, strength development, and heavy metal immobilization effects, were then investigated. The results show that the coupling utilization of MgO and CLDH showed good performance. The strength of the Mg 2 -CLDH 3 sample was approximately 2.94 MPa after curing for 56 d, which was higher than that of the OPC-based sample. Moreover, the cost of the modified Na 2 CO 3 -activated binder was lower than that of the OPC-based binder. Modified sample showed satisfactory heavy metal immobilization effects. These findings demonstrate that carbonate-activated binder modified by supplementary materials can be suitable in CPB.