CA3094533C - Processing of a bitumen froth treatment overflow stream from froth treatment tailings for enhanced recovery of bitumen - Google Patents

Abstract

A process and system for treating froth treatment tailing (FTT) affected tailings that contain oxidized bitumen is provided. The process includes subjecting the FTT-affected tailings to a gas bubble-assisted separation, which can include for instance a floatation stage, a stripping stage or both, to produce a recovered bitumen froth stream and a tailings stream. The recovered bitumen froth stream can then be subjected to a concentrating treatment, for instance in a centrifuge, to reduce the water content recovered bitumen froth stream and produce a bitumen-enriched stream and an aqueous residual stream that includes water and solids. The bitumen-enriched stream can then be combined with an additional bitumen stream from a primary extraction process or from a secondary extraction process to produce a blended bitumen stream that is suitable for introduction into the secondary extraction process.

Description

I
PROCESSING OF A BITUMEN FROTH TREATMENT OVERFLOW STREAM FROM
FROTH TREATMENT TAILINGS FOR ENHANCED RECOVERY OF BITUMEN
TECHNICAL FIELD
[001] The technical field generally relates to the treatment of tailings, and more particularly the treatment of bitumen froth generated from froth treatment tailings prior to further bitumen extraction.
BACKGROUND

[002] Various types of tailings materials are produced in mining and extraction operations. For example, in oil sands extraction operations, several streams of coarse and fine tailings are produced and typically supplied to tailings ponds for storage.

[003] One type of tailings stream that is produced by bitumen froth treatment contains light hydrocarbons, such as diluent or solvent, that are part of the froth treatment process, and residual bitumen. In bitumen froth treatment, a light hydrocarbon is added to the bitumen froth in order to enhance the separation of the bitumen components from the aqueous and mineral solids components of the bitumen froth. In naphthenic froth treatment (NFT), the light hydrocarbon in naphtha. In paraffinic froth treatment (PFT), the light hydrocarbon is a paraffinic solvent. In either case, some of the light hydrocarbon reports to the underflow tailings streams in the froth treatment process and residual amounts can thus be present in the tailings stream. Residual amounts of bitumen can also be entrained with the tailings stream.

[004] Froth treatment tailings are typically supplied to a tailings pond and therefore the light hydrocarbons can be present in various parts of the tailings pond.
Tailings that have been affected by the light hydrocarbons of froth treatment and that are found in the tailings pond can be referred to as froth treatment tailings affected tailings or "FTT
affected tailings".

[005] The light hydrocarbons found in such tailings support microbial activity and can impact or alter aquatic closure performance as well as add to greenhouse gas and volatile organic compound emissions. In addition, the bitumen found in the FIT-affected tailings oxidizes when stored in tailings ponds. Further processing of FTT-affected tailings to extract oxidized bitumen therefrom can be a challenge since bitumen streams obtained Date Recue/Date Received 2020-09-25 from FTT-affected tailings, i.e., oxidized bitumen, can lead to the formation of emulsions and rag layers when reintroduced into the extraction process.

[006] As a result, there remain a number of challenges related to the management, handling, and treating of FTT-affected tailings deposited in tailings ponds.
SUMMARY

[007] There is provided a process for treating froth treatment tailing (FTT) affected tailings that contain oxidized bitumen, comprising:
subjecting the FIT-affected tailings to a gas bubble-assisted separation to produce a recovered bitumen froth stream and a tailings stream;
concentrating the recovered bitumen froth stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids;
combining the bitumen-enriched stream with an additional bitumen stream from a primary extraction process or from a secondary extraction process to produce a blended bitumen stream; and introducing the blended bitumen stream into the secondary extraction process.

[008] In some implementations, the primary extraction process generates a primary bitumen froth stream and the additional bitumen stream comprises the primary bitumen froth stream.

[009] In some implementations, the primary extraction process generates a secondary bitumen froth introducible into the secondary extraction process and the additional bitumen stream comprises the secondary bitumen froth stream.

[0010] In some implementations, the primary extraction process generates a primary bitumen froth stream and the secondary extraction process comprises supplying the primary bitumen froth stream to an inclined plate separator (IPS) to produce a bitumen product stream and an IPS underflow stream.
Date Recue/Date Received 2020-09-25

[0011] In some implementations, the additional bitumen stream comprises the IPS
undertow stream.

[0012] In some implementations, the secondary extraction process comprises supplying the IPS underflow stream to a cyclone to produce a cyclone overflow stream and a cyclone undertow stream.

[0013] In some implementations, the additional bitumen stream comprises the cyclone overflow stream.

[0014] In some implementations, the process further comprises combining the bitumen-enriched stream with a further additional bitumen stream from the primary extraction process or from the secondary extraction process to produce a further blended bitumen stream suitable for introduction into the secondary extraction process.

[0015] In some implementations, bitumen contained in the additional bitumen stream is substantially non-oxidized.

[0016] In some implementations, the blended bitumen stream is free of caustic.

[0017] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.

[0018] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

[0019] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is less than 25:75 by weight.

[0020] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

[0021] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.
Date Recue/Date Received 2020-09-25

[0022] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

[0023] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight,

[0024] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

[0025] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

[0026] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

[0027] In some implementations, the recovered bitumen froth stream has a bitumen content of at least 5% w/w.

[0028] In some implementations, the recovered bitumen froth stream has a bitumen content of less than about 10% w/w.

[0029] In some implementations, the recovered bitumen froth stream has a bitumen content of less than about 8% w/w.

[0030] In some implementations, the water content of the recovered bitumen froth stream is at least 70% w/w.

[0031] In some implementations, concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by at least 50%.

[0032] In some implementations, concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by between 50% and 70%.

[0033] In some implementations, concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by at least 70%.
Date Recue/Date Received 2020-09-25

[0034] In some implementations, concentrating the recovered bitumen froth stream comprises subjecting the recovered bitumen froth stream to centrifugation.

[0035] In some implementations, the bitumen-enriched stream comprises at least wt% of bitumen.

[0036] In some implementations, the bitumen-enriched stream comprises at least wt% of bitumen.

[0037] In some implementations, the bitumen-enriched stream comprises less than 50 wt% of water.

[0038] In some implementations, the bitumen-enriched stream comprises less than 40 wt% of solids.

[0039] In some implementations, the aqueous residual stream is recyclable to another part of the process.

[0040] In some implementations, the aqueous residual stream is recyclable to the gas bubble-assisted separation for diluting the FTT-affected tailings.

[0041] In some implementations, the aqueous residual stream is recyclable to the gas bubble-assisted separation for heating the FTT-affected tailings.

[0042] In some implementations, the FTT-affected tailings comprise mature fine tailings (MFT) retrieved from a tailings pond.

[0043] In some implementations, the FTT-affected tailings comprises diluent in a concentration above 'I 000ppm or above 2000ppm upon retrieval from the tailings pond.

[0044] In some implementations, the gas bubble-assisted separation is operated such that between 50% and 90%, or between 55% and 80%, of the diluent in the FTT-affected tailings is removed.

[0045] In some implementations, the gas bubble-assisted separation is operated such that at least 90% of the diluent in the FTT-affected tailings is removed.
Date Recue/Date Received 2020-09-25

[0046] In some implementations, the gas bubble-assisted separation comprises at least one of a floatation stage and a stripping stage, each one of the floatation stage and the stripping stage comprising providing gas bubbles and agitation in a corresponding vessel.

[0047] In some implementations, the floatation stage comprises providing gas bubbles and agitation in a floatation vessel to produce a bitumen froth overflow stream and floatation tailings that are withdrawn from the floatation vessel.

[0048] In some implementations, the stripping stage comprises providing gas bubbles in a stripper vessel to produce a stripped bitumen stream and stripped tailings that are withdrawn from the stripper vessel.

[0049] In some implementations, the process further comprises subjecting the tailings stream to dewatering, comprising:
adding an immobilization chemical and a flocculant to the tailings stream to produce a flocculated tailings material;
supplying the flocculated tailings material into a mine pit to form a permanent aquatic storage structure (PASS) that includes a settled solids-rich layer containing contaminants of concern and a water cap.

[0050] In some implementations, at least a portion of the aqueous residual stream is recycled to part of the dewatering process.

[0051] In accordance with another aspect, there is provided a process of recovering bitumen from an oxidized bitumen stream, the process comprising:
concentrating the oxidized bitumen stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids;
combining the bitumen-enriched stream with an additional bitumen stream from a primary extraction process or from a secondary extraction process to produce a blended bitumen stream; and introducing the blended bitumen stream into the secondary extraction process.
Date Recue/Date Received 2020-09-25

[0052] In some implementations, the primary extraction process generates a primary bitumen froth stream and the additional bitumen stream comprises the primary bitumen froth stream.

[0053] In some implementations, the primary extraction process generates a secondary bitumen froth introducible into the secondary extraction process and the additional bitumen stream comprises the secondary bitumen froth stream.

[0054] In some implementations, the primary extraction process generates a primary bitumen froth stream and the secondary extraction process comprises supplying the primary bitumen froth stream to an inclined plate separator (IPS) to produce a bitumen product stream and an IPS underflow stream.

[0055] In some implementations, the additional bitumen stream comprises the IPS
underflow stream.

[0056] In some implementations, the secondary extraction process comprises supplying the IPS underflow stream to a cyclone to produce a cyclone overflow stream and a cyclone underflow stream.

[0057] In some implementations, the additional bitumen stream comprises the cyclone overflow stream.

[0058] In some implementations, the process further comprises combining the bitumen-enriched stream with a further additional bitumen stream from the primary extraction process or from the secondary extraction process to produce a further blended bitumen stream suitable for introduction into the secondary extraction process.

[0059] In some implementations, bitumen contained in the additional bitumen stream is substantially non-oxidized.

[0060] In some implementations, the blended bitumen stream is free of caustic.

[0061] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.
Date Recue/Date Received 2020-09-25

[0062] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

[0063] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream are combined is less than 25:75 by weight.

[0064] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

[0065] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.

[0066] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

[0067] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight.

[0068] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

[0069] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

[0070] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

[0071] In some implementations, the oxidized bitumen stream has a bitumen content of at least 5% w/w.

[0072] In some implementations, the oxidized bitumen stream has a bitumen content of less than about 10% w/w.

[0073] In some implementations, the oxidized bitumen stream has a bitumen content of less than about 8% w/w.
Date Recue/Date Received 2020-09-25

[0074] In some implementations, the water content of the oxidized bitumen stream is at least 70% w/w.

[0075] In some implementations, concentrating the oxidized bitumen stream comprises reducing a volume of the oxidized bitumen stream by at least 50%.

[0076] In some implementations, concentrating the oxidized bitumen stream comprises reducing a volume of the recovered bitumen froth stream by between 50% and 70%.

[0077] In some implementations, concentrating the oxidized bitumen stream comprises reducing a volume of the oxidized bitumen stream by at least 70%.

[0078] In some implementations, concentrating the oxidized bitumen stream comprises subjecting the oxidized bitumen stream to centrifugation.

[0079] In some implementations, the bitumen-enriched stream comprises at least wt% of bitumen.

[0080] In some implementations, the bitumen-enriched stream comprises at least wt% of bitumen.

[0081] In some implementations, the bitumen-enriched stream comprises less than 50 wt% of water.

[0082] In some implementations, the bitumen-enriched stream comprises less than 40 wt% of solids.

[0083] In some implementations, the oxidized bitumen stream is obtainable from a gas bubble-assisted separation for treating FTT-affected tailings, the gas bubble-assisted separation comprising providing gas bubbles and agitation in a corresponding vessel.

[0084] In some implementations, the gas bubble-assisted that comprises subjecting the FTT-affected tailings to at least one of a floatation stage and a stripping stage.

[0085] In some implementations, the floatation stage comprises providing gas bubbles and agitation in a floatation vessel to produce a bitumen froth overflow stream and floatation tailings that are withdrawn from the floatation vessel.
Date Recue/Date Received 2020-09-25

[0086] In some implementations, the stripping stage comprises providing gas bubbles in a stripper vessel to produce a stripped bitumen stream and stripped tailings that are withdrawn from the stripper vessel.

[0087] In some implementations, the aqueous residual stream is recyclable to another part of the process.

[0088] In some implementations, the aqueous residual stream is recyclable to the gas bubble-assisted separation for diluting the FTT-affected tailings.

[0089] In some implementations, the aqueous residual stream is recyclable to the gas bubble-assisted separation for heating the FTT-affected tailings.

[0090] In some implementations, the F7-affected tailings comprise mature fine tailings (MFT) retrieved from a tailings pond.

[0091] In some implementations, the FTT-affected tailings comprises diluent in a concentration above 1000ppm or above 2000ppm upon retrieval from the tailings pond.

[0092] In some implementations, the gas bubble-assisted separation is operated such that between 50% and 90%, or between 55% and 80%, of the diluent in the FTT-affected tailings is removed.

[0093] In some implementations, the gas bubble-assisted separation is operated such that at least 90% of the diluent in the FTT-affected tailings is removed.

[0094] In some implementations, the process further comprises subjecting the tailings stream to dewatering, comprising:
adding an immobilization chemical and a flocculant to the tailings stream to produce a flocculated tailings material;
supplying the flocculated tailings material into a mine pit to form a permanent aquatic storage structure (PASS) that includes a settled solids-rich layer containing contaminants of concern and a water cap.

[0095] In some implementations, at least a portion of the aqueous residual stream is recycled to part of the dewatering process.
Date Recue/Date Received 2020-09-25

[0096] In accordance with another aspect, there is provided a system for treating froth treatment tailing (FTT) affected tailings that includes oxidized bitumen, comprising:
a gas bubble-assisted separation unit configured to receive the FTT affected tailings and produce a recovered bitumen froth stream and a tailings stream, the gas bubble-assisted separation unit comprising a froth outlet to withdraw the recovered bitumen froth stream and a tailings outlet to withdraw the tailings stream;
a concentration unit in fluid communication with the froth outlet of the gas bubble-assisted separation unit to concentrate the bitumen froth stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids; and a pipeline assembly in fluid communication with the concentration unit for supplying the bitumen-enriched stream to a separation unit of a secondary extraction process.

[0097] In some implementations, the system further comprises a retrieval assembly comprising a pipeline and a pump for retrieving FTT-affected tailings from a tailings source.

[0098] In some implementations, the gas bubble-assisted separation unit comprises at least one of a floatation unit and a stripping unit.

[0099] In some implementations, the floatation unit comprising at least one floatation vessel.

[00100] In some implementations, the stripping unit comprising at least one stripping vessel.

[00101] In some implementations, the concentration unit comprises one or more centrifuges.

[00102] In some implementations, the pipeline assembly is further configured to transport an additional bitumen stream to form a blended stream with the bitumen-enriched stream Date Recue/Date Received 2023-03-07 for supplying the blended stream to the separation unit of the secondary extraction process.

[00103] In some implementations, the additional bitumen stream comprises primary bitumen froth obtained from a primary separation vessel (PSV) of a primary extraction process.

[00104] In some implementations, the additional bitumen stream comprises secondary bitumen froth obtained from a secondary separation vessel (SSV) of a primary extraction process.

[00105] In some implementations, the separation unit comprises an inclined plate separator (IPS) configured to produce a bitumen product stream and an IPS
underflow stream.

[00106] In some implementations, the additional bitumen stream comprises the IPS
underflow stream from the secondary extraction process.

[00107] In some implementations, the separation unit comprises a cyclone configured to produce a cyclone overflow stream and a cyclone underflow stream.

[00108] In some implementations, the additional bitumen stream comprises the cyclone overflow stream from the secondary extraction process.

[00109] In some implementations, the pipeline assembly is further configured to transport and supply the bitumen-enriched stream to a further separation unit of the secondary extraction process.

[00110] In some implementations, the additional bitumen stream comprises a substantially non-oxidized bitumen stream.

[00111] In some implementations, the blended bitumen stream is free of caustic.

[00112] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.
Date Recue/Date Received 2020-09-25

[00113] In some implementations, the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

[00114] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream are combined is less than 25:75 by weight.

[00115] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

[00116] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.

[00117] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

[00118] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight.

[00119] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

[00120] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

[00121] In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

[00122] In some implementations, the recovered bitumen froth stream has a bitumen content of at least 5% w/w.

[00123] In some implementations, the recovered bitumen froth stream has a bitumen content of less than about 10% w/w.

[00124] In some implementations, the recovered bitumen froth stream has a bitumen content of less than about 8% w/w.
Date Recue/Date Received 2020-09-25

[00125] In some implementations, the water content of the recovered bitumen froth stream is at least 70% w/w.

[00126] In some implementations, the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by at least 50%.

[00127] In some implementations, the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by between 50% and 70%.

[00128] In some implementations, the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by at least 70%.

[00129] In some implementations, the bitumen-enriched stream comprises at least 20 wt% of bitumen.

[00130] In some implementations, the bitumen-enriched stream comprises at least 25 wt% of bitumen.

[00131] In some implementations, the bitumen-enriched stream comprises less than 50 wt% of water.

[00132] In some implementations, the bitumen-enriched stream comprises less than 40 wt% of solids.

[00133] In some implementations, the tailings source is a tailings pond.

[00134] In some implementations, the retrieval assembly comprises a dredge or a barge.

[00135] In some implementations, the retrieval assembly is configured to access mature fine tailings (MFT) from the tailings pond to obtain the FTT-affected tailings.

[00136] In some implementations, the system further comprises a dilution assembly configured to add a dilution liquid to the FTT-affected tailings prior to the gas bubble-assisted separation.

[00137] In some implementations, the dilution assembly is in fluid communication with the aqueous residual stream, and the dilution liquid comprises aqueous residual stream.
Date Recue/Date Received 2020-09-25

[00138] In some implementations, the system further comprises a controller provided upstream of the concentration unit to control the flowrate of the recovered bitumen froth stream being supplied thereto.

[00139] In some implementations, the system further comprises a controller provided downstream of the concentration unit to control the ratio at which the bitumen-enriched stream is combined with the additional bitumen stream.

[00140] It should be understood that the processes and systems as described above can have further features that are described below or illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWING

[00141] Figure 1 is a process flow diagram illustrating an example of a process for concentrating a recovered bitumen froth stream produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process, the treatment including a floatation stage followed by a stripping stage.

[00142] Figure 2 is a process flow diagram illustrating another example of a process for concentrating a recovered bitumen froth stream produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process.

[00143] Figure 3 is a process flow diagram illustrating another example of a process for concentrating a recovered bitumen froth stream produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process.

[00144] Figure 4 is a process flow diagram illustrating another example of a process for concentrating a bitumen froth overflow produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process, the treatment including a floatation stage.

[00145] Figure 5 is a process flow diagram illustrating another example of a process for concentrating a stripped bitumen stream produced following treatment of froth treatment Date Recue/Date Received 2020-09-25 affected tailings for reintroduction into a secondary extraction process, the treatment including a stripping stage.

[00146] Figure 6 is a process flow diagram illustrating another example of a process for concentrating a recovered bitumen froth stream produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process, the treatment including a floatation stage followed by a stripping stage.

[00147] Figure 7 is a process flow diagram illustrating an example of a process for concentrating a recovered bitumen froth stream produced following treatment of froth treatment affected tailings for reintroduction into a secondary extraction process, the treatment including a stripping stage followed by a floatation stage.
DETAILED DESCRIPTION

[00148] Techniques described herein relate to processes and systems for treating froth treatment affected tailings to produce a bitumen-enriched stream that includes residual bitumen and that is suitable for reintroduction into a secondary extraction process of the main oil sands processing plant. For example, the processes can include subjecting the tailings to a gas bubble-assisted separation to produce a bitumen froth stream and a tailings stream, and concentrating the bitumen froth stream to obtain the bitumen-enriched stream that includes residual bitumen. The gas bubble-assisted separation can include subjecting the froth treatment affected tailings to a floatation stage to produce a bitumen froth overflow and floatation tailings. The gas bubble-assisted separation can also include subjecting the froth treatment affected tailings to a stripping stage to produce a vapor overhead stream that contains diluent or solvent, stripped bitumen, and stripped tailings that are suitable for treatment in a dewatering process. In some implementation, the gas bubble-assisted separation can include both a floatation stage and a stripping stage, performed sequentially in any order. When the gas bubble-assisted separation includes both a floatation stage and a stripping stage, the bitumen froth overflow and the stripped bitumen stream can be combined to form a recovered bitumen froth stream, and the recovered bitumen froth stream can be subjected to a concentration treatment to reduce a water content thereof and produce a bitumen-enriched stream. Alternatively, each one of the bitumen froth overflow and the stripped bitumen can be referred to as recovered bitumen, and be subjected to the concentration treatment. The bitumen-enriched stream Date Recue/Date Received 2020-09-25 can then be reintroduced in a given ratio relative to a "fresh" bitumen stream into the bitumen froth treatment, or secondary extraction process. In some implementations, the gas bubble-assisted separation and the concentration treatment can facilitate converting a waste bitumen stream from tailings into a bitumen stream that is suitable for reintroduction into the secondary extraction process of the main oil sands processing plant.

[00149] As discussed, further processing of FTT-affected tailings to extract oxidized bitumen therefrom can be a challenge since bitumen streams obtained from FTT-affected tailings, i.e., oxidized bitumen, can lead to the formation of emulsions and rag layers when reintroduced into the extraction process. Although washing of oxidized bitumen with caustic is feasible to mitigate these drawbacks, the addition of caustic can be costly and time-consuming, and alternative treatments are desirable to minimize addition of caustic.
The bitumen froth overflow stream from the floatation process can thus be considered an oxidized bitumen froth overflow stream, and the stripped bitumen stream from the stripping process can also be considered an oxidized stripped bitumen stream.
Accordingly, the combination of the oxidized bitumen froth overflow and oxidized stripped bitumen can be referred to as an oxidized recovered bitumen froth stream. Concentrating the oxidized recovered bitumen froth stream and combining the resulting oxidized bitumen-enriched stream with an additional bitumen stream that is non-oxidized, i.e., a "fresh"
bitumen stream from a primary extraction process or from a secondary extraction process, in a given ratio, can enable the oxidized bitumen-enriched stream to be reintroduced in the extraction process to further extract bitumen therefrom. In some implementations, by concentrating the oxidized recovered bitumen froth stream and combining the resulting oxidized bitumen-enriched stream with an additional bitumen stream that is non-oxidized to form a blended bitumen stream that is suitable for reintroduction in the secondary extraction process, the addition of caustic can be avoided.

[00150] The cleaned FTT-affected tailings that are produced following the gas bubble-assisted separation can be subjected to a dewatering process that can include the addition of an immobilization chemical as well as a flocculant in order to produce a flocculated tailings material that is supplied into a mine pit or other containment structure in order to form a permanent aquatic storage structure (PASS) having a water cap and a bottom settled solids layer that contains and entraps contaminants of concern.
Date Recue/Date Received 2020-09-25

[00151] Various techniques and systems will now be described for treating FTT-affected tailings to extract residual bitumen therefrom.
General overview of a bitumen recovery process and treatment of FTT affected tailings

[00152] Referring to Figure 1, in a primary extraction operation, oil sands ore 10 is mined and crushed in a crushing unit 12 to obtain a crushed ore 13. The crushed ore 13 is mixed with water 14 in a mixing unit 16, such as a rotary breaker, to form an aqueous slurry 18 comprising bitumen. The aqueous slurry 18 is then conditioned to prepare the bitumen for separation from the aqueous slurry 18. The conditioning can be performed for instance by transportation of the aqueous slurry 18 from one location to another. The aqueous slurry 18 is subsequently supplied to a primary separation vessel 20, also referred to as a PSV, for separation into primary bitumen froth 22 and primary tailings 24. The primary tailings 24 can be further treated or be deposited in a tailings pond for settling.

[00153] In some implementations, the bitumen froth 22 can include between about 40 wt% and about 70 wt% bitumen, between about 20 wt% and about 50 wt% water, and between about 5 wt% and about 15 wt% solid materials. The primary tailings 24, and secondary tailings if produced, generally include between about 45 wt% and about 55 wt%
solid materials, between about 45 wt% and about 55 wt% water, and between about 1 wt% and about 3 wt% of residual bitumen.

[00154] The bitumen froth 22 is treated in a secondary extraction process 34, or froth treatment process. In the illustrated implementation of the secondary extraction process 34, the bitumen froth 22 is diluted with a diluent 36 to obtain a diluted bitumen froth. As mentioned above, the diluent 36 can be either a naphthenic type diluent or a paraffinic type diluent. The naphthenic type diluent can for example include toluene, naphtha or other light aromatic compounds. The paraffinic type diluent can for example include C4 to C8 aliphatic compounds and/or natural gas condensate. The diluted bitumen froth can then be supplied to an inclined plate separator 40, also referred to as an IPS, to be separated into a bitumen product 38 and an IPS underflow 42 that includes residual bitumen, residual diluent, water, solids, and other contaminants. In the illustrated implementation, the IPS underflow stream 42 is subjected to an additional treatment in a cyclone 44 to produce a cyclone overflow stream 46 and a cyclone underflow stream 48.
Date Recue/Date Received 2020-09-25 The cyclone overflow stream 46 can be combined with the primary bitumen froth 22 for reintroduction into the IPS 20, or be recycled back directly to the IPS 40.
The cyclone underflow stream 48 can be further treated in a diluent recovery unit 50 to recover a portion of the diluent 36 therefrom as recovered diluent 51, and produce froth treatment tailings 52. The froth treatment tailings 52 can then be deposited in a froth treatment tailings pond 42 for settling.

[00155] In some implementations, and with reference to Figure 2, the primary separation vessel 20 can also produce a middlings stream 21 that can be supplied to a secondary separation vessel 23, also referred to as a SSV, to be separated into secondary bitumen froth 25 and secondary tailings 27. The secondary bitumen froth 25 can be fed back to the primary separation vessel 20, be combined with the primary bitumen froth 22, or alternatively, be used as a feed stream for the secondary extraction process 34.

[00156] Referring back to Figure 1, a tailings stream can be retrieved from the tailings pond 54. The tailings stream can be retrieved from a mature fine tailings (MFT) layer of the tailings pond 54. It is noted that the tailings stream can also be obtained from various tailings sources that include "fluid tailings". This tailings stream can be referred to as FTT-affected tailings, affected MFT, "aMFT", or FTT-affected fluid tailings, for example. A pump 58 can be used to retrieve the affected MFT 56 from the tailings pond 54 and supply the affected MFT 56 to a separation process 60, which will be described in more detail below.
The pump could also be a dredge or a barge. While the FIT-affected tailings 56 that are supplied to the separation process 60 are typically from an MFT layer of a tailings pond, they can also be sourced from other FTT-affected tailings sources and could include or consist of FTT supplied directly from the froth treatment operation. The tailings that are fed into the separation process 60 can be any combination of FTT, FTT-affected tailings, and other tailings materials that contain or are affected by light hydrocarbons. It is also noted that tailings not affected by light hydrocarbons can be combined with the affected tailings to form the tailings stream fed into the separation process 60.

[00157] The separation process 60 can include a gas bubble-assisted separation 102 and a concentration treatment 96. The gas bubble-assisted separation 102 can include at least one of a floatation stage and a stripping stage, or can include any other types of stages that enable production of a recovered bitumen froth stream from FTT-affected tailings.
When the gas bubble-assisted separation 102 includes both a floatation stage and a Date Recue/Date Received 2020-09-25 stripping stage, the floatation stage and the stripping stage can be performed sequentially in any order. Thus, either one of the floatation stage and the stripping stage, or a combination of the floatation stage and the stripping stage, can be referred as a gas bubble-assisted separation 102. In some implementations, given operating parameters can contribute distinguishing between a floatation stage and a stripping stage. For instance, in some implementations, a floatation stage can be characterized by a low superficial gas velocity and a high mechanical input, while a stripping stage can be characterized by a higher superficial gas velocity and a lower mechanical input. In the following paragraphs, additional details are provided regarding the optional implementation that includes a floatation stage and a stripping stage.

[00158] Still referring to Figure 1, the gas bubble-assisted separation 102 can include a floatation unit 62 as a first separation stage. The floatation unit 62 can include a floatation vessel 64, a mixing system that can include an agitator or mixer 66, an air inlet 68, and as well as overflow and underflow outlets. The floatation stage is operated to produce at least a bitumen froth overflow 70 and a floatation tailings 72. Other outlets, such as a middlings outlet, can be provided if desired.

[00159] The affected tailings stream 56 can be directly pumped into the floatation unit 64, or it can be pre-treated to change one or more properties. For example, as shown in Figure 1, water 74 can be added to the affected MFT 56 prior to introduction into the floatation unit 62 or into the floatation vessel 64 itself. The water can be recycled water from another part of the process, as will be discussed in further detail below. This pre-dilution of the affected tailings 56 can be performed depending on the solids content and other properties of the tailings retrieved from the pond 54. For example, if high solids MFT
(e.g., around 40 wt% solids) is retrieved from the pond 54, it can be diluted with water to a solids content of 10 to 30 wt%, or 15 to 20 wt%, prior to being subjected to the separation process 60, and in the scenario shown in Figure 1, prior to introduction into the flotation unit 62.

[00160] In some implementations, the floatation stage can employ relatively low air flow rate as well as relatively high mechanical energy input, e.g., provided by the mechanical agitator 66, in order to induce formation of an upper zone of bitumen froth and a lower zone of bitumen-depleted tailings.
Date Recue/Date Received 2020-09-25

[00161] Still referring to Figure 1, the floatation tailings 72 produced by the floatation stage can then be sent to a stripping stage that includes a stripper unit 76 as a second separation stage. The stripper unit 76 includes a stripping vessel 78 with a feed inlet for the floatation tailings 72, an outlet for the stripped bitumen stream 84, as well as an overhead outlet and a bottom outlet. The stripper unit 76 also includes an air inlet 80 for injecting air into the tailings material, as well as a mixing system that can include an agitator or mixer 82. Other inlets and outlets can also be provided, if desired.

[00162] The stripping stage can be operated as a polishing stage in order to recover residual bitumen from the floatation tailings 72 and remove small amounts of light hydrocarbon that may remain within the floatation tailings 72. The stripping stage produces a vapor overhead 86 that includes both air and stripped light hydrocarbons, stripped bitumen 84, and stripped tailings 88 which is substantially depleted in bitumen and light hydrocarbons. The stripped tailings 88 may include, for example, below 250ppm or below 100ppm of light hydrocarbons, such as diluent. The stripped tailings 88 may also have a diluent content that represents at least 90% recovery compared to the diluent content of the affected MFT 56 and/or at least 50 to 70% recovery compared to the diluent content of the floatation underflow which is the bitumen-depleted tailings stream.

[00163] While an example of the floatation and stripping stages have been described above, it should be noted that there are various possible implementations of these first and second stages of the gas bubble-assisted separation 102. Some of the possible implementations, including equipment that could be used, will be discussed further below.

[00164] As shown in Figure 1, the stripped tailings 88 from the stripper unit 76 can then be supplied to a dewatering stage 90. There are various types of dewatering operations that exist that can be used for separating water from the mineral solids contained in the stripped tailings 88. In one example, the dewatering operation includes adding an immobilization chemical to the stripped tailings 88 followed by a flocculant in order to produce a flocculated tailings material, which is then conditioned in a pipeline and supplied to a permanent aquatic storage structure, "PASS" 92. In the PASS 92, the flocculated solids with immobilized contaminants of concern settle to the bottom to form a settled solids layer, and a water cap forms as an upper layer of the PASS 92. Various details regarding this type of potential dewatering operation can be found described in Canadian Date Recue/Date Received 2020-09-25 patent document Nos. CA 2,958,873 and 2,921,835.

[00165] It is also noted that alternative dewatering processes can be used.
For example, in one dewatering process, a flocculant solution can be added to the stripped tailings 88 in order to produce a flocculated tailings material which can then be pipeline conditioned and deposited in thin lifts on a sloped sub-aerial deposition area in order to form a dry tailings material and allowing the water to drain and flow away from the drying solids.
Various other dewatering processes can also be used and can involve filters, thickeners, deposition methods, and various other techniques.

[00166] Still referring to Figure 1, the bitumen froth overflow 70 from the floatation unit 62 and the stripped bitumen stream 84 from the stripper unit 76 can be combined to form a recovered bitumen froth stream 94 that is subjected to the concentration treatment 96. It is to be noted that in other implementations, either one of the bitumen froth overflow 70 and the stripped bitumen stream 84 can be subjected to the concentration treatment 96 as a standalone stream, i.e., without being priorly combined together, and can thus each be also referred to as a recovered bitumen froth stream.

[00167] The concentration treatment 96 can advantageously enable a reduction of the volume of the recovered bitumen froth stream 94, which in turn can contribute to reducing the volume that needs to be disposed of in a tailings pond, or if the recovered bitumen froth is to be returned to the secondary extraction process, can reduce the need for caustic addition to avoid the formation of rag layers and stable emulsions. The concentration treatment 96 can thus enable the production of cleaner tailings by reducing the bitumen content thereof, and enable recovery of bitumen from what would otherwise be considered as a waste stream.

[00168] The recovered bitumen froth stream 94 can have a variable composition depending on the operation of the floatation unit 62 and the stripper unit 76.
In some implementations, the floatation unit 62 may produce for instance a bitumen froth overflow 70 comprising between about 5 wt% and about 10 wt% of bitumen, between about 70 wt%
and about 85 wt% of water, and between about 10 wt% and about 15 wt% of solids. The stripper unit 76 may produce a stripped bitumen stream 84 having a similar composition to that of the bitumen froth overflow stream 70, albeit in a smaller amount than the Date Recue/Date Received 2022-09-23 floatation unit 62 in terms of mass. Thus, once the bitumen froth overflow 70 and the stripped bitumen 84 are combined to form the resulting recovered bitumen froth stream 94, the recovered bitumen froth stream 94 can have a composition that comprises between about 5 wt% and about 10 wt% of bitumen, between about 70 wt% and about 85 wt% of water, and between about 10 wt% and about 15 wt% of solids.

[00169] The recovered bitumen froth stream 94, or alternatively either one of the bitumen froth overflow stream 70 and the stripped bitumen stream 84, can be subjected to the concentration treatment 96 in order to separate residual bitumen and diluent from water and solids. The concentration treatment 96 can thus be performed to reduce the water content of the recovered bitumen froth stream 94, thereby producing a bitumen-enriched stream 98 that has an increased concentration of bitumen and a lower concentration of water in comparison with the recovered bitumen froth stream 94. Subjecting the recovered bitumen froth stream 94 to a concentration treatment 96 can be beneficial to reduce the large volume taken up by water in bitumen streams derived from tailings, such large volume of water often impairing the suitability of these bitumen streams to be reintroduced into the secondary extraction process. The concentration treatment 96 produces an aqueous residual stream 100 that comprises mainly water, Le., above about 90 wt% of water, traces of bitumen, and between about 2 wt% and about 10 wt% solids, and that can be used as recycled water in other parts of the process. In addition, the removal of residual bitumen from the aqueous residual stream 100 can contribute to improving consolidation and reduce flocculant usage in PASS applications.

[00170] In some implementations, the concentration treatment 96 can be performed to produce a bitumen-enriched stream 98 that comprises between about 20 wt% and about 30 wt% of bitumen, between about 35 wt% and about 55 wt% of water, and between about 30 wt% and about 40 wt% of solids. In some implementations, the concentration treatment 96 can facilitate achieving a volume reduction of the recovered bitumen froth stream 94 of at least about 60%. The concentration treatment 96 can be performed to facilitate production of a bitumen-enriched stream 98 that may be suitable for reintroduction at various entry points into the extraction process of the main oil sands processing plant, as will be discussed further below.
Date Recue/Date Received 2020-09-25

[00171] The concentration treatment 96 can include one or more concentration units configured for receiving the recovered bitumen froth stream 94 and for producing the bitumen-enriched stream 98 and the aqueous residual stream 100.

[00172] With reference to Figure 3, in some implementations, the concentration unit can include one or more centrifuges 104. The operating parameters of the concentration treatment 96 can be adapted depending on various factors, such as the type of light hydrocarbons that are present in the FTT-affected tailings 56, the concentration of bitumen in the recovered bitumen froth stream 94, etc. Examples of operating parameters that can be adapted include the G-force applied, the bowl rotation speed, the differential speed, and the height of the weir plates. In some scenarios, modifying the differential speed and G-force of the centrifuge can contribute to enhance the separation process.

[00173] In some implementations, the centrifugation can be performed without additives, and at temperatures ranging from about 15 C to about 25 C. In other implementations, additives such as coagulants and/or flocculants can be used to enhance separation of water from the bitumen present in the recovered bitumen froth stream 94.
Coagulants and/or flocculants that can be used can include those that are suitable for wastewater treatment.

[00174] The concentration treatment 96 can also include any apparatus that may be suitable to achieve a reduction in water content of the recovered bitumen froth stream 94, while concentrating bitumen into a bitumen-enriched stream 98. Additional examples of apparatus that can be suitable to perform such concentration treatment can include any devices or apparatus that can produce a G-force to separate water from the bitumen froth.
For instance, in some implementations, one or more cyclones can be used to perform the concentration treatment 96. In some scenarios, when more than one cyclones are used, the cyclones can be operated in series.

[00175] Figures 4 to 7 illustrate examples of various implementations of a gas bubble-assisted separation 102. As mentioned above, it is to be noted that when a single stage is performed in the context of the gas bubble-assisted separation 102, the recovered bitumen froth stream can be designated by a reference to that specific stage, or alternatively, as a "recovered bitumen froth stream". For instance, in the case of the floatation unit 62, bitumen froth recovered therefrom can be referred to as a bitumen froth Date Recue/Date Received 2020-09-25 overflow 70, and in the case of the stripper unit 76, bitumen froth recovered therefrom can be referred to as a stripped bitumen 84. When the gas bubble-assisted separation 102 includes more than one stage, the combination of the bitumen froth streams recovered from these stages can be referred to as a "recovered bitumen froth stream", such as shown in Figures 1, 6 and 7. Thus, irrespective of the number and types of stages performed as part of the gas bubble-assisted separation 102, bitumen froth recovered from the gas bubble-assisted separation 102 can be referred to as a recovered bitumen froth stream 94, such as shown in Figure 2. In addition, the tailings stream produced by the gas bubble-assisted separation 102 can be generally referred to as a tailings stream 110, although specific expressions may also be used to designate tailings from a given stage, as depicted in the figures. For instance, with reference to Figure 1, tailings from the floatation stage 62 are referred to as floatation tailings 72, and tailings from the stripping stage 76 are referred to as stripped tailings 88. Also to be noted is that in Figures 4 to 7, the additional bitumen stream is shown as a primary bitumen froth 22. However, it is to be understood that the additional bitumen stream of Figures 4 to 7 can include any additional bitumen stream as defined herein.

[00176] Referring back to Figure 1, the bitumen-enriched steam 94 can be combined with an additional bitumen stream to subsequently be reintroduced into the secondary extraction process 34 of the main oil sands processing plant. Several options for the additional bitumen stream are possible, and various aspects may be taken into consideration when determining which additional bitumen stream the bitumen-enriched stream 98 may be combined with.

[00177] For instance, an aspect that may be taken into consideration when determining which additional bitumen stream the bitumen-enriched stream 98 may be combined with is whether the additional bitumen stream includes non-oxidized bitumen. As mentioned above, bitumen from FTT-affected tailings can be subjected to oxidation when stored in tailings ponds, and form oxidized bitumen. On the other hand, the various streams produced upstream of the tailings pond 54 are considered to include non-oxidized bitumen since they have not been subjected to oxidation in a tailings pond, and are sometimes referred to as a "fresh" streams. With reference to Figures 1 and 2, in the implementations shown, examples of non-oxidized streams include the primary bitumen froth 22, the middlings 21, the secondary bitumen froth 25, the IPS underflow 42, the cyclone overflow 46, the cyclone underflow 48 stream, and the froth treatment tailings 52 stream, which are Date Recue/Date Received 2020-09-25 streams that also correspond to inputs or outputs of a secondary extraction process that uses a diluent or a solvent. As one of the objectives when combining the bitumen-enriched stream 98 with an additional bitumen stream is to reintroduce the bitumen-enriched stream 98 into the extraction process for further bitumen extraction, suitable additional bitumen streams can be those that are non-oxidized.

[00178] Another aspect that may be taken into consideration when determining which additional bitumen stream the bitumen-enriched stream 98 may be combined with is that since the bitumen-enriched stream 98 is derived from a froth treatment extraction process that uses a diluent or solvent to facilitate separation of certain components, the bitumen-enriched stream 98 may contain traces of residual diluent or residual solvent.
Suitable additional bitumen streams can thus include those that are inputs or outputs of an extraction process that uses a diluent or solvent, such as the secondary extraction process 34 illustrated in Figure 1. Accordingly, in the context of the implementation shown in Figure 1, suitable additional bitumen streams can include the primary bitumen froth 22, the IPS
underflow 42, and the cyclone overflow 46. As the primary separation vessel 20 typically operates without the presence of a diluent or solvent, the bitumen-enriched stream 98 would generally not be combined with the aqueous slurry 18 as the additional bitumen stream, or with another stream that is reintroduced into the primary separation vessel 20.
When the secondary separation vessel 23 is operated such that a at least a portion of the secondary bitumen froth 25 is introduced directly into the secondary extraction process 34, this portion of the secondary bitumen froth 25 can be a suitable additional stream to be combined with the bitumen-enriched stream 98, as illustrated in Figure 2.

[00179] It is to be understood that the example of the secondary extraction process 34 shown in Figure 1 is for illustrative purposes only, and that several alternatives to the various units and configuration thereof may be contemplated. For instance, in some implementations of a secondary extraction process, a centrifuge may be used.
Accordingly, the examples of additional bitumen streams provided hereinabove are given in the context of the illustrated implementation, and may thus vary depending on the units and configuration used in alternative bitumen secondary extraction processes.
In addition, in some implementations, the secondary extraction process 34 may include more than one stage for a given portion of the secondary extraction process, which can also result in more options of additional bitumen streams for combining with the bitumen-enriched stream 98. For instance, there may be more than one IPS units, and/or more than one Date Recue/Date Received 2020-09-25 cyclones, and additional bitumen streams can be obtained from any stages of the more than one IPS units and the more than one cyclones.

[00180] In some implementations, the bitumen-enriched stream 98 can be introduced back into the secondary extraction process 34 at more than one location. For instance and with reference to Figure 1, a first portion of the bitumen-enriched stream 98 can be combined with the primary bitumen froth 22, a second portion of the bitumen-enriched stream 98 can be combined with the IPS underflow 42, and a third portion of the bitumen-enriched stream 98 can be combined with the cyclone overflow 46. With reference to Figure 2, another portion of bitumen-enriched stream 98 can be combined with a portion of secondary bitumen froth 25 that is introduced in the secondary extraction process 34.
When the bitumen-enriched stream 98 is introduced back into the secondary extraction process 34 at more than one location, the bitumen-enriched stream 98 can be said to be combined with the additional bitumen stream and with a further additional bitumen stream.
In other words, the bitumen-enriched stream 98 can be combined with primary bitumen froth 22 as the additional bitumen stream, and with the IPS underflow 42 and/or the cyclone overflow 46 as the further additional bitumen stream. Alternatively, the bitumen-enriched stream 98 can be combined with secondary bitumen froth 25 as the additional bitumen stream, and with the IPS underflow 42 and/or the cyclone overflow 46 as the further additional bitumen stream. In another alternative, the bitumen-enriched stream 98 can be combined with the IPS underflow 42 as the additional bitumen stream, and with the cyclone overflow 46 as the further additional bitumen stream. Other combinations are of course possible depending on the configuration of the secondary extraction process 34.

[00181] Combining the bitumen-enriched stream with an additional bitumen stream can be done at given ratios to achieve certain results. As detailed above, a challenge associated with the reintroduction of a bitumen stream derived from FTT-affected tailings is that the presence of oxidized bitumen can lead to the formation of rag layers and stable emulsions once reintroduced in the secondary extraction process, which can be deleterious to the separation performance. Rag layers are an undesirable mixture of dispersed bitumen droplets and water stabilized by fine solids, asphaltenes and surfactants that accumulates between the bitumen phase and the aqueous phase and that can impair separation performance. Stable emulsions can be formed by the accumulation of asphaltene aggregates and fine particles at the bitumen-water interface.
These types of multiphase mixtures can remain stable for periods of time that are longer than typical Date Recue/Date Received 2020-09-25 residence times in froth treatment separators, and can also contribute to impairing separation performance. In some implementations, determining the ratio of the bitumen-enriched stream 98 relative to the additional bitumen stream can thus be a key factor to mitigate possible deleterious impacts on the separation process performance, for instance with regard to the formation of rag layers and/or stable emulsions. This ratio of bitumen-enriched stream 98 relative to the additional bitumen stream can also be understood as corresponding to a ratio of an oxidized bitumen stream relative to a non-oxidized bitumen stream.

[00182] In some implementations, the ratio of the bitumen-enriched stream 98 relative to the additional bitumen stream can be determined such that caustic addition to wash the oxidized bitumen may not be required to avoid formation of rag layers and/or stable emulsions. In other words, determining a given ratio of the bitumen-enriched stream 98 relative to the additional bitumen stream, for given characteristics of each of these two streams, for reintroduction into the secondary extraction process can contribute to facilitate the separation performance during the secondary extraction process without having to rely on the addition of caustic for preventing or minimizing the risk of formation of rag layers and stable emulsions. In such implementations, the operating costs would be significantly reduced by the avoidance of caustic additives to counter the effects of oxidized bitumen.

[00183] The ratio of the bitumen-enriched stream 98 relative to the additional bitumen stream may change depending on whether the additional bitumen stream is a primary bitumen froth, an IPS underflow stream, or a cyclone overflow stream, as the composition of each of these streams can differ, for instance in terms of bitumen content or water content

[00184] Although the combination of the bitumen-enriched stream 98 with the additional bitumen stream for reintroduction into the extraction process can be done in accordance to a given ratio to avoid addition of caustic, it is to be understood that addition of caustic may nonetheless be beneficial in some implementations of the process described herein, and depending on the characteristics of the additional bitumen stream. In such implementations, the amount of caustic added would nonetheless be smaller than typically required when oxidized bitumen is reintroduced in an extraction process.
Date Recue/Date Received 2020-09-25

[00185] In some implementations, the ratio the bitumen-enriched stream 98 relative to the additional bitumen stream can be less about 25:75 by weight, or less than 0.4.
In some implementations, the proportion of bitumen-enriched stream 98 relative to the additional bitumen stream can be less than 30 wt%. In some implementations, the ratio the bitumen-enriched stream 98 relative to the additional bitumen stream can be at least 5:95 by weight. In some implementations, the ratio of the bitumen-enriched stream and the additional bitumen stream can range from 5:95 by weight to 30:70 by weight, from 8:92 by weight to 25:75 by weight, from 10:90 by weight to 20:80 by weight, or 12:88 by weight to 18:82 by weight. In a specific embodiment of the process, when the bitumen-enriched stream 98 is combined with the IPS underflow stream 42 or the cyclone overflow 46, the ratio of the bitumen-enriched stream 98 relative to the IPS underflow stream 42 can be about 10:90 by weight. In another specific embodiment of the process, when the bitumen-enriched stream 98 is combined with the IPS underflow stream 42 or the cyclone overflow 46, the ratio of the bitumen-enriched stream 98 relative to the IPS underflow stream 42 can be about 20:80 by weight.

[00186] Referring to Figure 3, in some implementations, a controller 108 can be provided upstream of the concentration treatment 96, which in Figure 3 is exemplified as including a centrifuge 104. The controller 108 can be operatively connected to a valve to control the flowrate of the recovered bitumen froth stream 94 or of the bitumen froth stream 106 being fed into the centrifuge 104, such as the centrifuge 104 illustrated in Figure 3. A controller 108 provided upstream of the concentration unit 96 can contribute to control the operation of the centrifuge 104 so as to achieve a desired level of concentration of the resulting bitumen-enriched stream 98. The composition of the recovered bitumen froth stream 94 or of the bitumen froth stream 106 being fed into the concentration treatment 96 can also be assessed upstream of the centrifuge 104, and the operation of the centrifuge 104 can be adapted accordingly. In some implementations, a controller 108 can be provided downstream of the centrifuge 104. The controller 108 provided downstream of the centrifuge 104 can contribute to control the ratio at which the bitumen-enriched stream 98 is combined with the additional bitumen stream, which in Figure 3 is illustrated as corresponding to a primary bitumen froth 22. The composition of the bitumen-enriched stream 98 being combined with an additional bitumen stream can also be assessed downstream of the centrifuge 104 to help determine the ratio at which the bitumen-Date Recue/Date Received 2020-09-25 enriched stream 98 is combined with the additional bitumen stream and/or determine with which additional bitumen stream the bitumen-enriched stream is to be combined.

[00187] Referring back to Figure 1, in some implementations, the aqueous residual stream 100 produced by the concentration treatment 96 can be recycled to various parts of the bitumen extraction process. For instance, the aqueous residual stream 100 can be used to dilute the affected tailings stream 56 prior to introduction into the floatation unit 62 to achieve a given composition of the affected tailings into the floatation unit Thus, the water recovered from the concentration treatment 96 can advantageously be fed back to the floatation unit 62, instead of using a fresh water source. In some implementations, the aqueous stream 100 can be considered sufficiently "clean" to be introduced into the PASS
92.
Alternative implementations of the floatation stage and the stripping stage

[00188] While the implementation shown in Figure 1 includes two ex situ vessels that are operated to perform the floatation stage followed by the stripping stage, it is to be understood that either one of the floatation stage and the stripping stage, or both, can be performed in situ treatment within the tailings pond 54 itself, and the resulting tailings material can be used in the process as described above and illustrated in Figure 1, where a floatation vessel and a stripping vessel are used. Various configurations of the floatation stage and the stripping stage performed in situ can be found described in Canadian patent document No. CA 3,037,959.

[00189] Briefly, various different types of ex situ and in situ vessels and equipment can be used to implement the floatation stage and the stripping stage. In one example, at least one of the floatation stage and the stripping stage can be performed using a conventional oil sands slurry floatation cell that has a tailings inlet, a conical bottom, and outlets for the underflow and an upper stream. Air can be provided via a sparger that is located within a lower part of the vessel, or introduced with the tailings feed, or a combination thereof. In other implementations, the floatation stage or the striping stage can be performed in a Baker' tank or a Jameson Cell, for example.

[00190] It should be noted that various different types of vessels and equipment could be used to implement the two-stage process described herein. Only some possible separators have been discussed above. Other types of vessels that could be used are Date Recue/Date Received 2022-09-23 separators that are typically used for mining applications or separators that are typically used for oil cleanup applications. Such separators do not have to be specially designed for a two-stage process such that one described herein. In addition, such separators do not have to be treated as a fixed asset of the plant or the overall processing operation but can be treated as a piece of temporary remediation equipment. For example, deployment of the separator may include providing a temporary foundation, that can be made of wooden beams and rig mats rather than a concrete foundation. The separator could also be on wheels to facilitate mobilization and relocation. Thus, the separators that are used for the two-stage process described herein can have a design and deployment strategy that is relatively different from those employed in conventional large-scale oil sands mining and extraction operations.

[00191] It is noted that the floatation and stripping vessels can be the same or different types of vessels. When using the same type of vessel, maintenance and replacement of vessels can be facilitated. Alternatively, each stage can use a different type of vessel that is specially adapted for the corresponding purpose and type of separation that is desired.
It is also noted that air bubbles can be provided using various mechanisms, such as spargers, upstream mixers, downcomers, and so on. The separation vessels can have additional features, such as a pump around, agitators, internal baffles, etc., if desired. In addition, the inlets and outlets of the separation vessels can have various different structures and features. For example, the froth collection system to recover froth overflow can include an overflow weir and/or a bitumen skimmer device at the top of the vessel.

[00192] The floatation stage and the stripping stage can also be implemented where the floatation vessel and the stripper are substantially similar or identical in terms of construction and equipment but would be operated using certain different operating parameters (e.g., mixing energy, air flow rates).

[00193] In some implementations, as mentioned above, the order of the floatation stage and the stripping stage can be reversed, i.e., the stripping stage can be performed first followed by the floatation stage, or the gas bubble-assisted separation can include either one of the floatation stage or the stripping stage. For instance, Figure 4 illustrates an implementation wherein the gas bubble-assisted separation includes a floatation stage that produces a bitumen froth overflow stream 70 that is subjected to the concentration treatment 96. Figure 5 illustrates an implementation wherein the bubble-assisted Date Recue/Date Received 2020-09-25 separation includes a stripping stage that produces stripped bitumen 84 that is subjected to the concentration treatment 96. Figure 6 illustrates an implementation wherein the gas bubble-assisted separation includes a floatation stage followed by a stripping stage, with a recovered bitumen froth stream 94 being subjected to the concentration treatment 96.
Figure 7 illustrates an implementation wherein the gas bubble-assisted separation includes a stripping stage followed by a floatation stage, with a recovered bitumen froth stream 94 being subjected to the concentration treatment 96.

[00194] It is noted that although a floatation stage and a stripping stage have been described herein to recover residual bitumen from FTT affected tailings that is subsequently subjected to a concentration treatment, other techniques can also be deployed to recover residual bitumen from FIT affected tailings to obtain a stream comprising residual bitumen that would have a satisfactory composition to be subjected to the concentration treatment described herein.
Date Recue/Date Received 2020-09-25

Claims (135)

33

1. A process for treating froth treatment tailing (FTT) affected tailings that contain oxidized bitumen, comprising:
subjecting the FTT-affected tailings to a gas bubble-assisted separation to produce a recovered bitumen froth stream and a tailings stream;
concentrating the recovered bitumen froth stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids;
combining the bitumen-enriched stream with an additional bitumen stream from a primary extraction process or from a secondary extraction process to produce a blended bitumen stream; and introducing the blended bitumen stream into the secondary extraction process.

2. The process of claim 1, wherein the primary extraction process generates a primary bitumen froth stream and the additional bitumen stream comprises the primary bitumen froth stream.

3. The process of claim 1, wherein the primary extraction process generates a secondary bitumen froth introducible into the secondary extraction process and the additional bitumen stream comprises the secondary bitumen froth stream.

4. The process of claim 1, wherein the primary extraction process generates a primary bitumen froth stream and the secondary extraction process comprises supplying the primary bitumen froth stream to an inclined plate separator (IPS) to produce a bitumen product stream and an IPS underflow stream.

5. The process of claim 4, wherein the additional bitumen stream comprises the IPS
underflow stream.

6. The process of claim 4, wherein the secondary extraction process comprises supplying the IPS underflow stream to a cyclone to produce a cyclone overflow stream and a cyclone underflow stream.
Date Recue/Date Received 2023-03-07

7. The process of claim 6, wherein the additional bitumen stream comprises the cyclone overflow stream.

8. The process of claim 1, further comprising combining the bitumen-enriched stream with a further additional bitumen stream from the primary extraction process or from the secondary extraction process to produce a further blended bitumen stream suitable for introduction into the secondary extraction process.

9. The process of any one of claims 1 to 8, wherein bitumen contained in the additional bitumen stream is substantially non-oxidized.

10. The process of any one of claims 1 to 9, wherein the blended bitumen stream is free of caustic.

11. The process of any one of claims 1 to 10, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.

12. The process of any one of claims 1 to 10, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

13. The process of claim 11 or 12, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is less than 25:75 by weight.

14. The process of claim 11 or 12, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

15. The process of claim 11 or 12, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.

16. The process of claim 15, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

17. The process of claim 15 or 16, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight.
Date Recue/Date Received 2023-03-07

18. The process of any one of claims 15 to 17, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

19. The process of claim 11 or 12, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

20. The process of claim 11 or 12, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

21. The process of any one of claims 1 to 20, wherein the recovered bitumen froth stream has a bitumen content of at least 5% w/w.

22. The process of any one of claims 1 to 20, wherein the recovered bitumen froth stream has a bitumen content of less than 10% w/w.

23. The process of any one of claims 1 to 20, wherein the recovered bitumen froth stream has a bitumen content of less than 8% w/w.

24. The process of any one of claims 1 to 23, wherein the water content of the recovered bitumen froth stream is at least 70% w/w.

25. The process of any one of claims 1 to 24, wherein concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by at least 50%.

26. The process of any one of claims 1 to 24, wherein concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by between 50% and 70%.

27. The process of any one of claims 1 to 24, wherein concentrating the recovered bitumen froth stream comprises reducing a volume of the recovered bitumen froth stream by at least 70%.

28. The process of any one of claims 1 to 27, wherein concentrating the recovered bitumen froth stream comprises subjecting the recovered bitumen froth stream to centrifugation.
Date Recue/Date Received 2023-03-07

29. The process of any one of claims 1 to 28, wherein the bitumen-enriched stream comprises at least 20 wt% of bitumen.

30. The process of any one of claims 1 to 28, wherein the bitumen-enriched stream comprises at least 25 wt% of bitumen.

31. The process of any one of claims 1 to 30, wherein the bitumen-enriched stream comprises less than 50 wt% of water.

32. The process of any one of claims 1 to 31, wherein the bitumen-enriched stream comprises less than 40 wt% of solids.

33. The process of any one of claims 1 to 32, wherein the aqueous residual stream is recycled to another part of the process.

34. The process of any one of claims 1 to 33, wherein the aqueous residual stream is recycled to the gas bubble-assisted separation for diluting the FTT-affected tailings.

35. The process of any one of claims 1 to 34, wherein the aqueous residual stream is recycled to the gas bubble-assisted separation for heating the FTT-affected tailings.

36. The process of any one of claims 1 to 35, wherein the FTT-affected tailings comprise mature fine tailings (M FT) retrieved from a tailings pond.

37. The process of claim 36, wherein the FTT-affected tailings comprises diluent in a concentration above 1000 ppm upon retrieval from the tailings pond.

38. The process of claim 36, wherein the FTT-affected tailings comprises diluent in a concentration above 2000 ppm upon retrieval from the tailings pond.

39. The process of claim 37 or 38, wherein the gas bubble-assisted separation is operated such that between 50% and 90% of the diluent in the FTT-affected tailings is removed.
Date Recue/Date Received 2023-03-07

40. The process of claim 37 or 38, wherein the gas bubble-assisted separation is operated such that between 55% and 80% of the diluent in the FTT-affected tailings is removed.

41. The process of claim 37 or 38, wherein the gas bubble-assisted separation is operated such that at least 90% of the diluent in the FTT-affected tailings is removed.

42. The process of any one of claims 1 to 41, wherein the gas bubble-assisted separation comprises at least one of a floatation stage and a stripping stage, each one of the floatation stage and the stripping stage comprising providing gas bubbles and agitation.

43. The process of claim 42, wherein the floatation stage comprises:
providing gas bubbles and agitation in a floatation vessel to produce a bitumen froth overflow stream and floatation tailings that are withdrawn from the floatation vessel.

44. The process of claim 42 or 43, wherein the stripping stage comprises:
providing gas bubbles in a stripper vessel to produce a stripped bitumen stream and stripped tailings that are withdrawn from the stripper vessel.

45. The process of any one of claims 1 to 44, further comprising subjecting the tailings stream to dewatering, comprising:
adding an immobilization chemical and a flocculant to the tailings stream to produce a flocculated tailings material;
supplying the flocculated tailings material into a mine pit to form a permanent aquatic storage structure (PASS) that includes a settled solids-rich layer containing contaminants of concern and a water cap.

46. The process of claim 45, wherein at least a portion of the aqueous residual stream is recycled to part of the dewatering process.
Date Recue/Date Received 2023-03-07

47. A process of recovering bitumen from an oxidized bitumen stream, the process comprising:
concentrating the oxidized bitumen stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids;
combining the bitumen-enriched stream with an additional bitumen stream from a primary extraction process or from a secondary extraction process to produce a blended bitumen stream; and introducing the blended bitumen stream into the secondary extraction process.

48. The process of claim 47, wherein the primary extraction process generates a primary bitumen froth stream and the additional bitumen stream comprises the primary bitumen froth stream.

49. The process of claim 47, wherein the primary extraction process generates a secondary bitumen froth introducible into the secondary extraction process and the additional bitumen stream comprises the secondary bitumen froth stream.

50. The process of claim 47, wherein the primary extraction process generates a primary bitumen froth stream and the secondary extraction process comprises supplying the primary bitumen froth stream to an inclined plate separator (IPS) to produce a bitumen product stream and an IPS underflow stream.

51. The process of claim 50, wherein the additional bitumen stream comprises the IPS
underflow stream.

52. The process of claim 50, wherein the secondary extraction process comprises supplying the IPS underflow stream to a cyclone to produce a cyclone overflow stream and a cyclone underflow stream.

53. The process of claim 52, wherein the additional bitumen stream comprises the cyclone overflow stream.
Date Recue/Date Received 2023-03-07

54. The process of any one of claims 47 to 53, further comprising combining the bitumen-enriched stream with a further additional bitumen stream from the primary extraction process or from the secondary extraction process to produce a further blended bitumen stream suitable for introduction into the secondary extraction process.

55. The process of any one of claims 47 to 54, wherein bitumen contained in the additional bitumen stream is substantially non-oxidized.

56. The process of any one of claims 47 to 55, wherein the blended bitumen stream is free of caustic.

57. The process of any one of claims 47 to 56, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.

58. The process of any one of claims 47 to 56, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

59. The process of claim 57 or 58, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream are combined is less than 25:75 by weight.

60. The process of claim 57 or 58, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

61. The process of any one of claims 47 to 56, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.

62. The process of claim 61, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

63. The process of claim 61 or 62, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight.
Date Recue/Date Received 2023-03-07

64. The process of any one of claims 61 to 63, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

65. The process of claim 57 or 58, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

66. The process of claim 57 or 58, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

67. The process of any one of claims 47 to 66, wherein the oxidized bitumen stream has a bitumen content of at least 5% w/w.

68. The process of any one of claims 47 to 66, wherein the oxidized bitumen stream has a bitumen content of less than 10% w/w.

69. The process of any one of claims 47 to 66, wherein the oxidized bitumen stream has a bitumen content of less than 8% w/w.

70. The process of any one of claims 47 to 69, wherein the water content of the oxidized bitumen stream is at least 70% w/w.

71. The process of any one of claims 47 to 70, wherein concentrating the oxidized bitumen stream comprises reducing a volume of the oxidized bitumen stream by at least 50%.

72. The process of any one of claims 47 to 70, wherein concentrating the oxidized bitumen stream comprises reducing a volume of the recovered bitumen froth stream by between 50% and 70%.

73. The process of any one of claims 47 to 70, wherein concentrating the oxidized bitumen stream comprises reducing a volume of the oxidized bitumen stream by at least 70%.

74. The process of any one of claims 47 to 73, wherein concentrating the oxidized bitumen stream comprises subjecting the oxidized bitumen stream to centrifugation.
Date Recue/Date Received 2023-03-07

75. The process of any one of claims 47 to 74, wherein the bitumen-enriched stream comprises at least 20 wt% of bitumen.

76. The process of any one of claims 47 to 74, wherein the bitumen-enriched stream comprises at least 25 wt% of bitumen.

77. The process of any one of claims 47 to 76, wherein the bitumen-enriched stream comprises less than 50 wt% of water.

78. The process of any one of claims 47 to 77, wherein the bitumen-enriched stream comprises less than 40 wt% of solids.

79. The process of any one of claims 47 to 78, wherein the oxidized bitumen stream is obtained from a gas bubble-assisted separation for treating FTT-affected tailings, the gas bubble-assisted separation comprising providing gas bubbles and agitation.

80. The process of claim 79, wherein the gas bubble-assisted separation comprises subjecting the FTT-affected tailings to at least one of a floatation stage and a stripping stage.

81. The process of claim 80, wherein the floatation stage comprises:
providing gas bubbles and agitation in a floatation vessel to produce a bitumen froth overflow stream and floatation tailings that are withdrawn from the floatation vessel.

82. The process of claim 80 or 81, wherein the stripping stage comprises:
providing gas bubbles in a stripper vessel to produce a stripped bitumen stream and stripped tailings that are withdrawn from the stripper vessel.

83. The process of any one of claims 79 to 82, wherein the aqueous residual stream is recycled to the gas bubble-assisted separation for diluting the FTT-affected tailings.
Date Recue/Date Received 2023-03-07

84. The process of any one of claims 79 to 83, wherein the aqueous residual stream is recycled to the gas bubble-assisted separation for heating the FTT-affected tailings.

85. The process of any one of claims 79 to 84, wherein the FTT-affected tailings comprise mature fine tailings (M FT) retrieved from a tailings pond.

86. The process of claim 85, wherein the FTT-affected tailings comprises diluent in a concentration above 1000 ppm upon retrieval from the tailings pond.

87. The process of claim 85, wherein the FTT-affected tailings comprises diluent in a concentration above 2000 ppm upon retrieval from the tailings pond.

88. The process of claim 86 or 87, wherein the gas bubble-assisted separation is operated such that between 50% and 90% of the diluent in the FTT-affected tailings is removed.

89. The process of claim 86 or 87, wherein the gas bubble-assisted separation is operated such that between 55% and 80% of the diluent in the FTT-affected tailings is removed.

90. The process of claim 86 or 87, wherein the gas bubble-assisted separation is operated such that at least 90% of the diluent in the FTT-affected tailings is removed.

91. The process of any one of claims 45 to 82, wherein the aqueous residual stream is recycled to another part of the process.

92. A system for treating froth treatment tailing (FTT) affected tailings that includes oxidized bitumen, comprising:
a gas bubble-assisted separation unit configured to receive the FTT
affected tailings and produce a recovered bitumen froth stream and a tailings stream, the gas bubble-assisted separation unit comprising a froth outlet to withdraw the recovered bitumen froth stream and a tailings outlet to withdraw the tailings stream;
Date Recue/Date Received 2023-03-07 a concentration unit in fluid communication with the froth outlet of the gas bubble-assisted separation unit to concentrate the recovered bitumen froth stream to reduce a water content thereof and produce a bitumen-enriched stream and an aqueous residual stream comprising water and solids; and a pipeline assembly in fluid communication with the concentration unit for supplying the bitumen-enriched stream to a separation unit of a secondary extraction process.

93. The system of claim 92, further comprising a retrieval assembly comprising a pipeline and a pump for retrieving FTT-affected tailings from a tailings source.

94. The system of claim 93, wherein the tailings source is a tailings pond.

95. The system of claim 93 or 94, wherein the retrieval assembly comprises a dredge or a barge.

96. The system of claim 94, wherein the retrieval assembly is configured to access mature fine tailings (MFT) from the tailings pond to obtain the FTT-affected tailings.

97. The system of any one of claims 93 to 96, further comprising a dilution assembly configured to add a dilution liquid to the FTT-affected tailings prior to the gas bubble-assisted separation.

98. The system of claim 97, wherein the dilution assembly is in fluid communication with the aqueous residual stream, and the dilution liquid comprises at least a portion of the aqueous residual stream.

99. The system of any one of claims 92 to 98, wherein the gas bubble-assisted separation unit comprises at least one of a floatation unit and a stripping unit.

100. The system of claim 99, wherein the floatation unit comprises at least one floatation vessel.

101. The system of claim 99, wherein the stripping unit comprises at least one stripping vessel.
Date Recue/Date Received 2023-03-07

102. The system of any one of claims 92 to 101, wherein the concentration unit comprises one or more centrifuges.

103. The system of any one of claims 92 to 102, further comprising a controller provided upstream of the concentration unit to control a flowrate of the recovered bitumen froth stream being supplied thereto.

104. The system of any one of claims 92 to 103, wherein the pipeline assembly is further configured to transport an additional bitumen stream to form a blended bitumen stream with the bitumen-enriched stream for supplying the blended bitumen stream to the separation unit of the secondary extraction process.

105. The system of claim 104, wherein the additional bitumen stream comprises primary bitumen froth obtained from a primary separation vessel (PSV) of a primary extraction process.

106. The system of claim 104, wherein the additional bitumen stream comprises secondary bitumen froth obtained from a secondary separation vessel (SSV) of a primary extraction process.

107. The system of claim 104, wherein the separation unit comprises an inclined plate separator (IPS) configured to produce a bitumen product stream and an IPS
underflow stream.

108. The system of claim 107, wherein the additional bitumen stream comprises the IPS
underflow stream from the secondary extraction process.

109. The system of claim 104, wherein the separation unit comprises a cyclone configured to produce a cyclone overflow stream and a cyclone underflow stream.

110. The system of claim 109, wherein the additional bitumen stream comprises the cyclone overflow stream from the secondary extraction process.

111. The system of any one of claims 104 to 110, wherein the additional bitumen stream comprises a substantially non-oxidized bitumen stream.

112. The system of any one of claims 104 to 111, wherein the blended bitumen stream is free of caustic.
Date Recue/Date Received 2023-03-07

113. The system of any one of claims 104 to 112, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of rag layers in the secondary extraction process is avoided.

114. The system of any one of claims 104 to 112, wherein the bitumen-enriched stream and the additional bitumen stream are combined in a ratio such that formation of stable emulsions in the secondary extraction process is avoided.

115. The system of claim 113 or 114, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream are combined is less than 25:75 by weight.

116. The system of claim 113 or 114, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is at least 5:95 by weight.

117. The system of claim 113 or 114, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 5:95 by weight to 30:70 by weight.

118. The system of claim 117, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 8:92 by weight to 25:75 by weight.

119. The system of claim 117 or 118, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 10:90 by weight to 20:80 by weight.

120. The system of any one of claims 117 to 119, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream ranges from 12:88 by weight to 18:82 by weight.

121. The system of claim 113 or 114, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 10:90 by weight.

122. The system of claim 113 or 114, wherein the ratio of the bitumen-enriched stream and the additional bitumen stream is about 20:80 by weight.

123. The system of any one of claims 113 to 122, further comprising a controller provided downstream of the concentration unit to control the ratio at which the bitumen-enriched stream is combined with the additional bitumen stream.
Date Recue/Date Received 2023-03-07

124. The system of any one of claims 92 to 123, wherein the recovered bitumen froth stream has a bitumen content of at least 5% w/w.

125. The system of any one of claims 92 to 123, wherein the recovered bitumen froth stream has a bitumen content of less than 10% w/w.

126. The system of any one of claims 92 to 123, wherein the recovered bitumen froth stream has a bitumen content of less than 8% w/w.

127. The system of any one of claims 92 to 126, wherein the water content of the recovered bitumen froth stream is at least 70% w/w.

128. The system of any one of claims 92 to 127, wherein the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by at least 0 % .

129. The system of any one of claims 92 to 127, wherein the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by between 50% and 70%.

130. The system of any one of claims 92 to 127, wherein the concentration unit is configured to reduce a volume of the recovered bitumen froth stream by at least 70%.

131. The system of any one of claims 92 to 130, wherein the bitumen-enriched stream comprises at least 20 wt% of bitumen.

132. The system of any one of claims 92 to 130, wherein the bitumen-enriched stream comprises at least 25 wt% of bitumen.

133. The system of any one of claims 92 to 132, wherein the bitumen-enriched stream comprises less than 50 wt% of water.

134. The system of any one of claims 92 to 133, wherein the bitumen-enriched stream comprises less than 40 wt% of solids.
Date Recue/Date Received 2023-03-07

135. The system of any one of claims 92 to 134, wherein the pipeline assembly is further configured to transport and supply the bitumen-enriched stream to a further separation unit of the secondary extraction process.
Date Recue/Date Received 2023-03-07