Nicholas Alvin Beier

481 Pages·2015·13.5 MB·English

Development of a Tailings Management Simulation and Technology
Evaluation Tool

by

Nicholas Alvin Beier

A thesis submitted in partial fulfillment of the requirements for the degree of

Doctor of Philosophy

in

Geo-Environmental Engineering

Department of Civil and Environmental Engineering
University of Alberta

© Nicholas Alvin Beier, 2015
ABSTRACT
This research aims to assist in the assessment of tailings management
technologies through the development of a dynamic simulation model. The
developed model (TMSim) incorporates the mine plan, various stages of
dewatering including classification, pre- and post-deposition dewatering, and an
impoundment material balance including tailings, process water, construction
material and capping materials. Through simulations of a simple metal mine
operation and a complex oil sands operation, TMSim demonstrated it can evaluate
technologies and mine plans and diagnose potential drawbacks and strengths.
This information can then be used to strategically guide and support technology
development and resource expenditure.
During the evaluation of oil sands fine tailings technologies, it was found that the
use of chemical amendments (flocculants) to augment dewatering and strength
gain may present some challenges. Chemically-amended fine tailings can have
low storage efficiencies and these deposits may exhibit sensitive, metastable
behavior upon deposition. Additionally, flocculation of fine tailings may actually
hinder the self-weight consolidation process through the development of an
apparent pre-consolidation pressure.
The TMSim modelling tool was utilized to simulate a model oil sands mine based
on the Syncrude Aurora North mine utilizing composite tailings (CT) technology.
Model inputs and functions were based on publicly available sources of
information. Based on the mass balance agreement with the Syncrude tailings
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plan, the TMSim model was established to be an effective quantitative tool that
can be used in the evaluation of technologies for oil sands mining operations.
A tailings plan was compiled using a novel dewatering technology, cross flow
filtration (CFF), as the core tailings technology. The CFF tailings plan was then
evaluated with the TMSim model and the model oil sands mine plan. The cross
flow filtration process provides an opportunity to deposit high density tailings
stacks requiring minimal containment. Two thirds of the yearly process water
demand can also be satisfied by immediate recycle from the CFF process resulting
in lower green house gas production. Additionally, if fluid fine tailings (FFT)
spiking is incorporated, existing inventories of FFT can be consumed and stored
in the pore space of the CFF tailings.

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Preface
The research in this thesis was completed by Nicholas Beier. Portions of Chapter
2 of this thesis have been published in the 2008 Canadian Geotechnical
Conference and 2009 Tailings and Mine Waste Conference. Mr. Beier was
responsible for the literature review and manuscript composition. M. Alostaz
assisted with the freeze-thaw dewatering summary in the manuscript. Co-authors
provided editing comments only.
Portions of Chapter 3 and 4 were previously published in the Tailings and Mine
Waste 2009 Conference, 2012 International Oil Sands Tailings Conference, and
the 5th International Young Geotechnical Engineers Conference (2013). Co-
authors provided editing comments only.
Versions of Chapter 6 were previously published in the 2012 Canadian
Geotechnical Conference and the Canadian Geotechnical Journal. Data was
collected and graciously provided by Shell Canada Energy (A. Dunmola). Mr.
Beier conducted the data analysis, presentation of data and wrote the manuscript.
Co-authors provided editing comments only.
A Portion of Chapter 8 was previously published in the 2014 International Oil
Sands Tailings Conference.
References:
Chapter 2
Beier, N. and Sego, D. (2008). Dewatering of Oil Sands Tailings Using Cross
Flow Filtration. 61st Canadian Geotechnical Conference and 9th joint IAH-
CNC Groundwater Specialty Conference, Edmonton, Alberta, September 22-
24, 2008. 8 pp.
Beier, N., Alostaz, M. and Sego, D. 2009. Natural Dewatering Strategies for Oil
Sands Fine Tailings. Tailings and Mine Waste 2009 Conference, Banff,
Alberta, November 1-4, 2009. 845-858.
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Beier, N., Sego, D., and Morgenstern, N. 2009. Dynamic Simulation of tailings
Management Options. Tailings and Mine Waste 2009 Conference, Banff,
Alberta, November 1-4, 2009. 441-450.
Chapter 3.
Beier, N., Sego, D., and Morgenstern, N. 2009. Dynamic Simulation of tailings
Management Options. Tailings and Mine Waste 2009 Conference, Banff,
Alberta, November 1-4, 2009. 441-450.
Beier, N. and Sego, D. 2013. Tailings Management in Canada’s Oil Sands. 5th
International Young Geotechnical Engineers Conference, Paris, France, 31
August – 1 September 2013, pp. 4.
Chapter 4.
Beier, N., Sego, D., and Morgenstern, N. 2012. Simulation of Tailings
Management Options. 3rd International Oil Sands Tailings Conference,
Edmonton, Ab. Dec 5-8, 2012. 9 pp.
Chapter 6.
Beier, N.A., Wilson, G.W., Dunmola, A., and Sego, D.C. 2012. Geotechnical
Aspects of Flocculation-based Technologies for Dewatering Mature Fine
Tailings. 65th Canadian Geotechnical Conference, Winnipeg, Manitoba,
September 30 – October 3, 2012. 8 pp.
Beier, N.A., Wilson, G.W., Dunmola, A., and Sego, D.C. 2013. Impact of
flocculation-based dewatering on the shear strength of oil sands fine tailings.
Canadian Geotechnical Journal, 2013, 50(9) 1001-1007.
Chapter 8.
Beier, N., Sego, D., and Morgenstern, N. 2014. Assessing a novel technology
using a tailings management simulation model. 4th International Oil Sands
Tailings Conference, Edmonton, Ab. Dec 7-10, 2014. 10 pp
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Acknowledgments
I would like to extend a sincere thank-you to my supervisors, Dr. Dave Sego and
Dr. N. Morgenstern for their patience, guidance, technical insight and financial
support over the course of my studies. The opportunities they have afforded me,
facilitated my growth both technically and professionally.
I would also like to thank Alan Fair and the COSIA Tailings EPA for the
opportunity to be involved with Tailings Roadmap project and for the many
technical discussions related to oil sands tailings technologies and management.
Thank you to Nathan Deisman for all your assistance with the numerical
modeling and code writing. I would also like to thank the many graduate students
I have worked with over years for their assistance in the lab and debates about
tailings including Sorta Amarebh, Reza Nik, Silawat Jeeravipoolvarn, Nam Pham
and Chenxi Zhang. Christine Hereygers, thank you for your technical assistance
in the lab and at the OSTRF and making yourself always available to help. Thank
you also Dr Scott, Dr. Wilson and Dr. Kabwe for insight and data on tailings
management and behavior. I was also a pleasure working with Sally Petaske and
the rest of the Geotechnial Centre staff.
This research would not have been possible without financial support from
Alberta Innovates Technology Futures (formerly Alberta Research Council),
NSERC, and the OSTRF. Their support is greatly appreciated. Additonally, the
software and support provided by GoldSim and FSConsol by Gord Pollock were
invaluable to the completion of the thesis.
Finally, I would like to thank my family, especially my wife, Kristina and our
children for their patience, love and support throughout my studies.

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Table of Contents
1 Introduction .................................................................................................. 1
1.1 Objective ............................................................................................... 4
1.2 Outline of Thesis ................................................................................... 5
1.3 Figures .................................................................................................. 7
1.4 References ............................................................................................. 9
2 Tailings Behaviour and Management .......................................................... 11
2.1 Introduction ......................................................................................... 11
2.2 Mine Waste Streams ............................................................................ 12
2.2.1 Dry Streams ........................................................................................... 12
2.2.2 Wet Streams .......................................................................................... 12
2.2.3 Wet Tailings Management ..................................................................... 13
2.3 Tailings Dewatering ............................................................................ 17
2.3.1 Hydrocyclones........................................................................................ 17
2.3.2 Thickeners ............................................................................................. 19
2.3.3 In-line Thickening ................................................................................... 21
2.3.4 Centrifuge .............................................................................................. 23
2.3.5 Filtration ................................................................................................ 25
2.4 Tailings Deposition ............................................................................. 28
2.4.1 Sub-aerial Deposition ............................................................................. 28
2.4.2 Sub Aqueous .......................................................................................... 29
2.4.3 Thickened and Paste Tailings .................................................................. 29
2.4.4 Dry Stack ................................................................................................ 30
2.4.5 Co-Disposal ............................................................................................ 30
2.4.6 Segregation of Tailings Slurry ................................................................. 31
2.4.7 Beach Slope Prediction ........................................................................... 33
2.5 Natural Dewatering Post Deposition .................................................... 36
2.5.1 Sedimentation ....................................................................................... 36
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2.5.2 Consolidation ......................................................................................... 37
2.5.3 Desiccation ............................................................................................ 42
2.5.4 Freeze –Thaw ......................................................................................... 45
2.5.5 Plant Dewatering ................................................................................... 47
2.6 Tailings Containment .......................................................................... 48
2.7 Conclusions ......................................................................................... 51
2.8 Tables .................................................................................................. 52
2.9 Figures ................................................................................................ 53
2.10 References ....................................................................................... 70
3 Tailings Management Simulation Model Development ............................... 84
3.1 Introduction ......................................................................................... 84
3.1.1 Tailings Management Evaluation ............................................................ 85
3.1.2 Objective ............................................................................................... 88
3.2 Tailings management system model .................................................... 89
3.2.1 Tailings Management ............................................................................. 89
3.2.2 Systems Model....................................................................................... 92
3.3 Simluation Model components ............................................................ 92
3.3.1 Performance Measures/Objectives ........................................................ 92
3.3.2 Extraction .............................................................................................. 94
3.3.3 Stage 1 Classification .............................................................................. 96
3.3.4 Stage 2 Dewatering. ............................................................................... 97
3.3.5 Stage 3 Dewatering .............................................................................. 100
3.3.6 Impoundment Sub-Model .................................................................... 110
3.3.7 User Decisions and Logic Conditions ..................................................... 119
3.4 Conclusions ....................................................................................... 122
3.5 Tables ................................................................................................ 125
3.6 Figures .............................................................................................. 126
3.7 References ......................................................................................... 144
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4 Tailings Management Simulation Model Implementation and Validation . 151
4.1 Introduction ....................................................................................... 151
4.1.1 Tailings Management ........................................................................... 151
4.1.2 Tailings Management Simulation ......................................................... 153
4.2 TMSim Development ........................................................................ 156
4.2.1 Modeling Software ............................................................................... 156
4.2.2 Model Structure ................................................................................... 157
4.2.3 Implementation of Model .................................................................... 158
4.3 Validation of Sub Systems ................................................................. 160
4.3.1 Sedimentation Sub-Model.................................................................... 161
4.3.2 Consolidation Sub-Model ..................................................................... 162
4.3.3 Deposition Algorithm ........................................................................... 163
4.3.4 Impoundment Mass Balance ................................................................ 165
4.4 Conclusions ....................................................................................... 167
4.5 Tables ................................................................................................ 169
4.6 Figures .............................................................................................. 171
4.7 References ......................................................................................... 186
5 Oil Sands Tailings Management ............................................................... 189
5.1 Introduction ....................................................................................... 189
5.2 Oil Sands Tailings ............................................................................. 189
5.2.1 Historical Tailings Management ........................................................... 191
5.2.2 Fluid Tailings Management .................................................................. 194
5.2.3 Site Specific Conditions Encountered in the Oil Sands........................... 194
5.3 2011 Oil Sand Tailings Management Plans ........................................ 196
5.3.1 Shell Canada ........................................................................................ 196
5.3.2 CNRL Horizon ....................................................................................... 198
5.3.3 Imperial Oil Canada .............................................................................. 199
5.3.4 Syncrude .............................................................................................. 199
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5.3.5 AERI Screening Study ........................................................................... 201
5.3.6 Summary of Mine Plan Data ................................................................. 202
5.4 Tailings Deposition Facilities ............................................................ 206
5.4.1 External Tailings Facility ....................................................................... 206
5.4.2 In-Pit Dykes .......................................................................................... 207
5.5 Waste Dumps .................................................................................... 208
5.6 Conclusions ....................................................................................... 209
5.7 Tables ................................................................................................ 210
5.8 Figures .............................................................................................. 215
5.9 References ......................................................................................... 221
6 Geotechnical Aspects of Flocculation-based Technologies for Dewatering
Mature Fine Tailings........................................................................................ 226
6.1 Introduction ....................................................................................... 226
6.1.1 Oil Sands Tailings Regulations .............................................................. 228
6.2 Fine Tailings Management ................................................................ 229
6.2.1 Fines Dewatering Methods Technologies ............................................. 230
6.3 Geotechnical Properties of Flocculated Fine tailings .......................... 232
6.3.1 Data Source ......................................................................................... 232
6.3.2 Material Properties .............................................................................. 232
6.3.3 Undrained Shear Strength of Oil Sand Tailings ...................................... 233
6.3.4 Shear Strength Sensitivity..................................................................... 235
6.3.5 Consolidation of Flocculated Tailings .................................................... 236
6.4 Implications of Fines Management Techniques using Flocculants...... 236
6.5 Conclusions ....................................................................................... 240
6.6 Tables ................................................................................................ 242
6.7 Figures .............................................................................................. 244
6.8 References ......................................................................................... 252
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