University of Oulu

He Niu, Mariam Abdulkareem, Harisankar Sreenivasan, Anu M. Kantola, Jouni Havukainen, Mika Horttanainen, Ville-Veikko Telkki, Paivo Kinnunen, Mirja Illikainen, Recycling mica and carbonate-rich mine tailings in alkali-activated composites: A synergy with metakaolin, Minerals Engineering, Volume 157, 2020, 106535, ISSN 0892-6875,

Recycling mica and carbonate-rich mine tailings in alkali-activated composites : a synergy with metakaolin

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Author: Niu, He1; Abdulkareem, Mariam2; Sreenivasan, Harisankar1;
Organizations: 1Fibre and Particle Engineering Research Unit, University of Oulu, P.O. Box 4300, FI-90570 Oulu, Finland
2Lappeenranta-Lahti University of Technology, School of Energy Systems, Department of Sustainability Science, P.O. Box 20, FI-53851 Lappeenranta, Finland
3NMR Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 10 MB)
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Language: English
Published: Elsevier, 2020
Publish Date: 2020-10-14


The main objective of this paper was to investigate the alkali activation of mine tailings (MT) after mechanochemical activation and the effect of metakaolin (MK) addition. Finnish mica-rich tailings from a phosphate mine were studied as precursors for alkali-activated materials (AAM) with a potential application as a substitute for ordinary Portland cement (OPC). The principal physical properties (water absorption, apparent porosity and unconfined compressive strength) were measured for samples containing 30% to 70% tailings. Zeolite phases such as natrolite and cancrinite were observed and the formation of C-(N)-A-S-H¹ and N-A-S-H gels was identified by XRD, DRIFT, FESEM-EDS and NMR technologies. A life cycle assessment (LCA) was conducted on specimens in comparison to OPC. This work indicated that phosphate MT can be recycled through alkali activation with lower CO₂ emission compared to all-metakaolin geopolymers and that the binder phase formed at the most promising tailings contents (60– 70%) was C-(N)-A-S-H gel.

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Series: Minerals engineering
ISSN: 0892-6875
ISSN-E: 1872-9444
ISSN-L: 0892-6875
Volume: 157
Article number: 106535
DOI: 10.1016/j.mineng.2020.106535
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: The authors gratefully acknowledge the financial support from the Academy of Finland [grants #292526, #319676 and #326291] and the European Union’s EU Framework Programme for Research and Innovation Horizon 2020 [Grant Agreement No 812580 (“SULTAN”,]. V.-V.T. thanks the Academy of Finland (grants #289649, 294027 and 319216) for the financial support.
EU Grant Number: (812580) SULTAN - European Training Network for the remediation and reprocessing of sulfidic mining waste sites
Academy of Finland Grant Number: 292526
Detailed Information: 292526 (Academy of Finland Funding decision)
319676 (Academy of Finland Funding decision)
319216 (Academy of Finland Funding decision)
289649 (Academy of Finland Funding decision)
294027 (Academy of Finland Funding decision)
Copyright information: © 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (