1. Evaluation of candidate polymers to maximize geotechnical performance of oil sands tailings
- Author
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Abdulnabi, Ahlam, Amoako, Kwaku, Moran, Daniel, Vanadara, Khushbu, Aldaeef, Abdulghader Abdulrahman, Esmaeilzadeh, Amin, Beier, Nicholas, Soares, Joao, and Simms, Paul
- Subjects
Tailings (Metallurgy) -- Properties ,Earth sciences - Abstract
Oil sands fluid fine tailings deposits are challenging to reclaim due to their inherently high natural water content, low permeability, and low strength. Combinations of polymers and (or) coagulants are used by operators to improve the dewatering and strength properties of the tailings. However, considerably more work has been done to evaluate polymer performance with short-term dewatering metrics rather than with long-term metrics such as consolidation properties. This paper evaluates the potential of four novel polymers for use in fluid fine tailings treatment compared to a commercially available polymer and untreated tailings specimen. The performance of the polymers was assessed through initial screening with respect to short-term dewatering, evaluation of the consolidation and strength properties using large-strain consolidation tests, shear sensitivity in pipeline transport, and finally, large-strain consolidation modelling to appraise the relative potential performance under different strategies, such as terrestrial or aquatic reclamation options. One polymer exhibits remarkably fast dewatering at high void ratios, while another demonstrates dense and shear-resistant flocs. The paper discusses each polymer's distinctive tailings fabrics and how their unique merits and limitations would benefit different reclamation eventualities. Finally, potential improvements of the polymers are suggested for future assessment. Key words: oil sands, tailings, polymers, consolidation, strength, modelling. Il est difficile de recuperer les depots de residus fins fluides de sables bitumineux en raison de leur teneur naturelle en eau elevee, de leur faible permeabilite et de leur faible resistance. Pour ameliorer les proprietes de deshydratation et de resistance des residus, les exploitants utilisent des combinaisons de polymeres et/ou de coagulants. Les performances des polymeres ont toutefois ete evaluees davantage en fonction de parametres de deshydratation a court terme qu'en fonction de parametres a long terme tels que les proprietes de consolidation. Le present document evalue le potentiel de quatre nouveaux polymeres pour une utilisation dans le traitement des residus fins fluides par rapport a un polymere offert sure le marche et a un echantillon de residus non traites. Les performances des polymeres ont ete evaluees par le biais d'une selection initiale concernant la deshydratation a court terme, revaluation des proprietes de consolidation et de resistance a l'aide d'essais de consolidation a grande deformation, la sensibilite au cisaillement dans le transport par pipeline et, enfin, la modelisation de la consolidation a grande deformation pour evaluer les performances potentielles relatives dans le cadre de differentes strategies, telles que les options de remise en etat terrestre ou aquatique. Les resultats montrent qu'un polymere presente une deshydratation remarquablement rapide a des taux de vide eleves, tandis qu'un autre presente des flocs denses et resistants au cisaillement. L'article aborde les materiaux de residus distinctifs de chaque polymere et la maniere dont leurs merites et limites uniques pourraient profiter a differentes eventualites de remise en etat. Enfin, des ameliorations potentielles des polymeres sont suggerees pour une evaluation future. [Traduit par la Redaction] Mots-cles: sables bitumineux, residus, polymeres, consolidation, resistance, modelisation., Introduction Surface mining of oil sands bitumen deposits produce tailings, which comprise water, sands, clays, residual hydrocarbons, and chemicals originating from the bitumen extraction process (Royal Society of Canada Expert [...]
- Published
- 2022
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