Impact of chemical and physical treatments on freeze-thaw dewatering of fluid fine tailings

Regulatory policy and regulations in Alberta require oil sands companies to reduce their production and storage of fluid fine tailings by creating deposits that can be reclaimed in a timely manner. To meet the regulatory requirements, some companies are adding flocculants to the fluid fine tailings and then using thickeners, inline flocculation or centrifuges to increase the solids content. Freeze–thaw and drying processes are then used to further dewater the tailings. The effects of flocculating, thickening, and freeze–thaw treatments were investigated by performing large-strain consolidation and shear strength tests on these treated fluid fine tailings. The consolidation and shear strength results were then compared with those of untreated fluid fine tailings. All of the treatments increased the hydraulic conductivity of the fluid fine tailings to some degree, but had little to no effect on the compressibility and shear strength. The effects of the treatment processes are discussed and evaluated.

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Field performance of in-line flocculated fluid fine tailings using thin lift deposition

Proceedings of the Sixth International Conference on Mine Closure ◽

10.36487/acg_rep/1152_50_wilson ◽

2011 ◽

Author(s):

Gordon Wilson ◽

Louis Kabwe ◽

Robert Donahue ◽

Rick Lahaie

Keyword(s):

Field Performance ◽

Fine Tailings ◽

Fluid Fine Tailings

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Oscillatory rheometry to characterize polymer flocculation of fluid fine tailings

Rheologica Acta ◽

10.1007/s00397-021-01276-2 ◽

2021 ◽

Author(s):

Mohammadhasan Sasar ◽

Cliff T. Johnston ◽

Heather Kaminsky ◽

Marika Santagata

Keyword(s):

Oscillatory Rheometry ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Polymer Flocculation

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Using Specified Risk Materials-Based Peptides for Oil Sands Fluid Fine Tailings Management

Materials ◽

10.3390/ma14071582 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1582

Author(s):

Yeling Zhu ◽

Yuki Gong ◽

Heather Kaminsky ◽

Michael Chae ◽

Paolo Mussone ◽

...

Keyword(s):

Oil Sands ◽

Colloidal Stability ◽

Free Water ◽

Value Added ◽

Settling Rate ◽

Test Range ◽

Tailings Management ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Hydrolyzed Polyacrylamide

Fluid fine tailings are produced in huge quantities by Canada’s mined oil sands industry. Due to the high colloidal stability of the contained fine solids, settling of fluid fine tailings can take hundreds of years, making the entrapped water unavailable and posing challenges to public health and the environment. This study focuses on developing value-added aggregation agents from specified risk materials (SRM), a waste protein stream from slaughterhouse industries, to achieve an improved separation of fluid fine tailings into free water and solids. Settling results using synthetic kaolinite slurries demonstrated that, though not as effective as hydrolyzed polyacrylamide, a commercial flocculant, the use of SRM-derived peptides enabled a 2-3-fold faster initial settling rate than the blank control. The pH of synthetic kaolinite tailings was observed to be slightly reduced with increasing peptides dosage in the test range (10–50 kg/ton). The experiments on diluted fluid fine tailings (as a representation of real oil sands tailings) demonstrated an optimum peptides dosage of 14 kg/ton, which resulted in a 4-fold faster initial settling rate compared to the untreated tailings. Overall, this study demonstrates the novelty and feasibility of using SRM-peptides to address intractable oil sands fluid tailings.

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Impact of flocculation-based dewatering on the shear strength of oil sands fine tailings

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0262 ◽

2013 ◽

Vol 50 (9) ◽

pp. 1001-1007 ◽

Cited By ~ 42

Author(s):

Nicholas Beier ◽

Ward Wilson ◽

Adedeji Dunmola ◽

David Sego

Keyword(s):

Oil Sands ◽

Material Handling ◽

Performance Criteria ◽

Regulatory Requirements ◽

Strength Performance ◽

Tailings Management ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Management Techniques ◽

Reported Data

The oil sands in northern Alberta have been mined to produce bitumen over the past five decades. Since the 1980s, technical advances have been made in mining, material handling, and bitumen extraction. However, acquiring practical methods to control and reduce the fluid fine tailings build-up has been an ongoing challenge. Recent regulatory changes have driven the industry to review current tailings-management techniques and investigate numerous alternative technologies and processes to manage and reclaim fine tailings. Many of these fine tailings–management techniques involve some form of polymer or chemical addition to promote dewatering and strength gain to meet the regulatory requirements. Based on the reported data, the chemically amended fine tailings deposits have the characteristics of sensitive, metastable deposits, necessitating additional mitigative measures by oil sands operators beyond the regulatory requirements. This paper explores the geotechnical aspects of meeting regulatory strength performance criteria by employing flocculation-based dewatering of fluid fine tailings.

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Addition of Tubifex accelerates dewatering of oil sands tailings

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0308 ◽

2016 ◽

Vol 43 (12) ◽

pp. 1025-1033 ◽

Cited By ~ 1

Author(s):

Xiaojuan Yang ◽

Miguel de Lucas Pardo ◽

Maria Ibanez ◽

Lijun Deng ◽

Luca Sittoni ◽

...

Keyword(s):

Oil Sands ◽

Land Reclamation ◽

Test Results ◽

Anionic Polymer ◽

Fine Tailings ◽

Fluid Fine Tailings ◽

Oil Sands Tailings ◽

Set Up ◽

Solids Content

Accelerating dewatering of fluid fine tailings (FFT) to facilitate land reclamation is a major challenge to the oil sands industry in Canada. A new method was tested, addition of Tubifex to FFT. Tubifex is an indigenous earthworm in Canada. The survival rate tests showed that Tubifex can survive in oil sands tailings and penetrate to 42 cm depth (maximum depth tested). Columns (5 L of FFT) were set-up with tailings alone, Tubifex treated tailings and polymer-Tubifex treated tailings. Test results showed that (a) the final mud–water interface of tailings alone was 26% higher than that of Tubifex treated tailings; (b) solids content of Tubifex treated tailings was 21% more than that of tailings alone; (c) Tubifex was capable to accelerate the dewatering process of both cationic and anionic polymer treated tailings; (d) anionic polymer was superior in facilitating long-term dewatering and its coupled effects with Tubifex were better than the cationic polymer.

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