Version 1
: Received: 6 August 2024 / Approved: 7 August 2024 / Online: 7 August 2024 (14:04:48 CEST)
How to cite:
Palma, G.; Bolaños, H.; Huamani, R.; Clements, C.; Hedayat, A. Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural and Toxicological Properties. Preprints2024, 2024080519. https://doi.org/10.20944/preprints202408.0519.v1
Palma, G.; Bolaños, H.; Huamani, R.; Clements, C.; Hedayat, A. Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural and Toxicological Properties. Preprints 2024, 2024080519. https://doi.org/10.20944/preprints202408.0519.v1
Palma, G.; Bolaños, H.; Huamani, R.; Clements, C.; Hedayat, A. Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural and Toxicological Properties. Preprints2024, 2024080519. https://doi.org/10.20944/preprints202408.0519.v1
APA Style
Palma, G., Bolaños, H., Huamani, R., Clements, C., & Hedayat, A. (2024). Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural and Toxicological Properties. Preprints. https://doi.org/10.20944/preprints202408.0519.v1
Chicago/Turabian Style
Palma, G., Cara Clements and Ahmadreza Hedayat. 2024 "Optimization of Geopolymers for Sustainable Management of Mine Tailings: Impact on Mechanical, Microstructural and Toxicological Properties" Preprints. https://doi.org/10.20944/preprints202408.0519.v1
Abstract
This study investigates the use of geopolymer technology as an alternative for the management of mine tailings, which is a serious environmental problem in mining environments including that of Arequipa region of Peru. In this study, the mixture of stabilized mine tailings with different percentages of binders (metakaolin and pumice) and their impact on the mechanical, microstructural, and toxicological properties of the synthesized geopolymers were analyzed. The ratios of mine tailings to binder material varied between 100/0 and 0/100. The activation was carried out with an alkaline solution of sodium hydroxide (10M) and sodium silicate (modulus 2.5). 50 mm cubic specimens were fabricated, and 7 mixtures with 3 replicates each were evaluated. The evaluations included compressive strength at 7, 14, 28, and 56 days of curing, chemical analysis by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR), microstructural characterization by Scanning Electron Microscopy (SEM/EDS), thermal behavior by thermogravimetry and differential thermal analysis (TGA/DTA) between 40°C and 1000°C, and toxicological tests by the Toxicity Characteristic Leaching Procedure (TCLP, EPA 1311) to determine the efficiency of immobilization of toxic metals. The results showed good mechanical strength, reaching 25 MPa at 7 days of curing, high microstructural stability with an average pore size of 7.21 μm, and good efficiency in the immobilization of heavy metals in geopolymers composed of 60% - 40% and 70% - 30% of the mine tailings - binders ratio, as the concentrations of As, Cd, Pb, Hg were below the established thresholds, acquiring the classification of non-hazardous materials. Geopolymers with 30 to 50% binder showed good mechanical behavior, microstructural stability, and high efficiency in the immobilization of heavy metals, complying with current regulations. Therefore, these geopolymers are suitable for various applications and in different environmental conditions.
Keywords
mine tailings; geopolymer; stabilization of heavy metals; encapsulation of heavy metals; metakaolin; pumice; compressive strength
Subject
Chemistry and Materials Science, Materials Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
