resumo
The mining industry produces a large quantity of sulphidic mine tailings, which cause several environmental issues during waste management. Currently, there is increasing interest in new technologies to recycle and utilize mine tailings more effectively in the future. In this present study, the geopolymerization of mine tailings has been studied. Suiphidic mine tailings from a gold mining site were activated with a NaOH solution and commercial ground granulated blast furnace slag (GGBFS) was used as a co-binder. Characterization of the mine tailings and the mechanical strength of the specimens produced were investigated. In addition, the effects of different NaOH concentrations and the amount of co-binder materials on a matrix were tested. The porosity of the specimens produced was evaluated using water absorption tests, the microstructure of the fractures was analyzed with field emission scanning electron microscope (FESEM), and the crystalline phases were identified by X-ray diffraction. The results show that the unconfined compressive strength (UCS) of the specimens produced from pure mine tailings was in the range of 13-3.5 MPa. The UCS increased and water permeability decreased with 5% GGBFS content in the mixture. By optimizing the NaOH concentration and GGBFS content, the UCS of the specimens varied from 1.8 MPa to 25 MPa. The alkali-activation of mine tailings allows binders to be made with sufficient compressive strength, which can be used as a backfill in mining sites or raw material in the construction industry. (C) 2016 Elsevier B.V. All rights reserved.
palavras-chave
SOLIDS-TO-LIQUID; PASTE BACKFILL; ACTIVATOR RATIOS; BRICKS; STABILIZATION; DRAINAGE
categoria
Engineering; Mineralogy; Mining & Mineral Processing
autores
Kiventera, J; Golek, L; Yliniemi, J; Ferreira, V; Deja, J; Illikainen, M
nossos autores
Victor Miguel Carneiro de Sousa Ferreira
Professor associadoGrupos
agradecimentos
This work was conducted as part of the ERA-MIN project 'GEOSULF' supported by the Finnish Agency for Technology and Innovation (TEKES), Portuguese National Funding Agency for Science, Research and Technology (FCT), The National Centre for Research and Development (BR) and various companies (Outotec, Agnico Eagle, and First Quantum Minerals). Mr. Jani Osterlund is acknowledged for his contribution to the laboratory analyses.