CA2915851C - Process for recovering bitumen from oil sands ore with aluminum-containing compounds - Google Patents

Abstract

Processes are provided for recovering bitumen from oil sands ore, comprising: adding one or more aluminum-containing compounds to an oil sands ore-water slurry; and liberating bitumen. Processes are also provided for extracting bitumen from an oil sand ore, comprising: (i) mixing oil sands ore with water or an aqueous solution to form a slurry; (ii) aerating the slurry to form a froth containing bitumen within the slurry; (iii) separating the froth from the slurry; (iv) adding one or more aluminum-containing compounds to the slurry prior to or during one or more of the preceding steps; and (v) liberating bitumen from the froth.

Description

PROCESS FOR RECOVERING BITUMEN FROM OIL SANDS ORE WITH
ALUMINUM-CONTAINING COMPOUNDS
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No.
62/096,360, filed December 23, 2014.
FIELD OF THE ART

[0002] The present embodiments relate to processes recovering bitumen from oil sands ore.
BACKGROUND

[0003] Bituminous sands, or oil sands, are a type of petroleum deposit. The sands contain naturally occurring mixtures of sand, clays, water, and a dense and extremely viscous form of petroleum technically referred to as bitumen (or colloquially "tar"
due to its similar appearance, odor, and color). Oil sands are found in large amounts in many countries throughout the world, but are found in extremely large quantities in Canada and Venezuela.
Oil sand deposits in northern Alberta in Canada contain approximately 1.6 trillion barrels of bitumen, and production from oil sands mining operations is expected to reach 1.5 million barrels of bitumen per day by 2020.

[0004] Oil sands reserves have only recently been considered to be part of the world's oil reserves, as higher oil prices and new technology enable them to be profitably extracted and upgraded to usable products. They are often referred to as unconventional oil or crude bitumen, in order to distinguish the bitumen extracted from oil sands from the free-flowing hydrocarbon mixtures known as crude oil traditionally produced from oil wells.

[0005] Conventional crude oil is normally extracted from the ground by drilling oil wells into a petroleum reservoir, and allowing oil to flow into them under natural reservoir pressures, although artificial lift and techniques such as water flooding and gas injection are usually required to maintain production as reservoir pressure drops toward the end of a field's life. Because extra-heavy oil and bitumen flow very slowly, if at all, toward producing wells under normal reservoir conditions, the sands may be extracted by either strip mining or the oil made to flow into wells by in situ techniques which reduce the viscosity such as by injecting steam, solvents, and/or hot air into the sands. These processes can use more water and require larger amounts of energy than conventional oil extraction, although many conventional oil fields also require large amounts of water and energy to achieve suitable production rates.

[0006] The original process for extraction of bitumen from the sands was developed by Dr. Karl Clark, working with Alberta Research Council in the 1920s. Today, the producers using surface mining processes use a variation of the Clark Hot Water Extraction (CHWE) process. In this process, the ores are mined using open-pit mining techniques. The mined ore is then crushed for size reduction, for example in relatively large tumblers or conditioning drums. Hot water at 40-80 C is added to the ore, forming a slurry.
The slurry may be conditioned and transported, for example using a piping system called hydrotransport line, to extraction units, for example to a primary separation vessel (PSV) in which a flotation process is used to recover bitumen as bitumen froth. The hydrotransport line may be configured to condition the oil sands stream while moving it to the extraction unit.
The water used for hydrotransport is generally cooler (but still heated) than in the tumblers or conditioning drums.

[0007] The displacement and liberation of bitumen from the sands is achieved by wetting the surface of the sand grains with an aqueous solution containing a caustic wetting agent, such as sodium hydroxide, sodium carbonate, sodium silicate or calcium hydroxide.
The resulting strong surface hydration forces operative at the surface of the sand particles give rise to the displacement of the bitumen by the aqueous phase. For example, sodium hydroxide is added to the slurry to maintain a basic pH, e.g., in the range of

8.0 to 10. This has the effect of dispersing fines (particle size less than 44 m) and clays from the oil sands and reducing the viscosity of the slurry, thereby reducing the particle size of the minerals in the oil sands.
[0008] Once the bitumen has been displaced and the sand grains are free, the components can be separated. Gravity can cause sand and rock from the slurry to settle to a bottom layer. A portion of the bitumen can float to the top based on the natural hydrophobicity exhibited by the free bituminous droplets at moderate pH
values, and can be removed as bitumen froth. An intermediate portion, often referred to as middlings, is relatively viscous and typically contains dispersed clay particles and some trapped bitumen which is not able to rise due to the viscosity. The middlings may then be exposed to froth flotation techniques to recover additional bitumen. (Hot water extraction of bitumen from Utah tar sands, Sepulveda et al. S. B. Radding, ed., Symposium on Oil Shale, Tar Sand, and Related Material - Production and Utilization of Synfuels: Preprints of Papers Presented at San Francisco, California, August 29 - September 3,1976; vol. 21, no. 6, pp.
110-122 (1976)).

[0009] The recovered bitumen froth generally consists of about 60% bitumen, 30%
water and 10% solids (sands and clay fines) by weight. The recovered bitumen froth may be cleaned to reject the contained solids and water to meet the requirement of downstream upgrading processes. Depending on the bitumen content in the ore, between 70 and 100% of the bitumen can be recovered using modern hot water extraction techniques from high grade ores.

[0010] The amount of bitumen and quality of the froth may be dependent, for example, on the bitumen's ability to separate from sand grains and attach to air. It has been observed that when the pH of the process is adjusted to between 8-10, organic acids in the bitumen may be neutralized into natural surfactants. These surfactants may improve bitumen-air attachment by lowering interfacial tension and they may separate the bitumen from sand grains by increasing interfacial charges. This improves the amount of bitumen which is recovered in the primary flotation process and helps to reduce the amount of solid particulate which is included in the froth.

[0011] Sodium hydroxide is used commercially to provide the alkaline environment for the CHWE process. Although, it is an economical process aid, sodium hydroxide is extremely corrosive and highly reactive, and therefore may require specialized engineering controls, protective equipment and personal hygiene measures. In addition, the use of sodium hydroxide can result in accumulation of sodium ions in recycled process water, which can cause dispersion of higher clays and can produce tailings with poor geotechnical properties that turn into mature fine tailings.
BRIEF SUMMARY

[0012] Disclosed herein are processes for recovering bitumen from oil sands ore wherein one or more aluminum-containing compounds are used as process aids. In one aspect, a process for recovering bitumen from oil sands ore, comprises: (i) adding one or more aluminum-containing compounds to an oil sands ore-water slurry wherein the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate; and (ii) liberating bitumen from the oils sands ore-water slurry. In another aspect, a process for extracting bitumen from an oil sands ore, comprises: (i) mixing oil sands ore with water or an aqueous solution to form a slurry; (ii) aerating the slurry to form a froth containing bitumen within the slurry; (iii) separating the froth from the slurry; (iv) adding one or more aluminum-containing compounds to the slurry prior to or during one or more of the preceding steps wherein the one Date Recue/Date Received 2022-01-26 or more aluminum-containing compounds comprises polyaluminum silicate sulfate;
and (v) liberating bitumen from the froth. In another aspect, a process for improving froth quality and bitumen recovery from an oil sands ore-water slurry comprises: (i) introducing the oil sands ore-water slurry into a primary separation cell; (ii) contacting an underwash water with the oil sands ore-water slurry, wherein the underwash water comprises an effective amount of one or more aluminum-containing compounds, wherein the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate; and (iii) allowing the oil sands ore-water slurry to separate into a froth layer and a middlings layer, wherein the froth layer comprises a lower mineral solids content than would be present without the addition of the one or more aluminum-containing compounds in the underwash water.
BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 shows the bitumen recovery data as a function of time for a low grade ore sample treated by an exemplary aluminum-containing compound in a Denver flotation cell.

[0014] Figure 2 shows the bitumen recovery as a function of time for a medium grade ore sample treated by an exemplary aluminum-containing compound in a Batch Extraction Unit.
DETAILED DESCRIPTION

[0015] Disclosed herein are processes for enhancing recovery of bitumen from oil sands. In particular, exemplary processes for the recovery of bitumen from oil sands ore involve a water-based extraction process whereby one or more aluminum-containing compounds are added to an oil sands ore-water slurry. The water-based extraction process of oil sands, or oil sands ore, refers to any known extraction process for producing aqueous tailings, including but not limited to the Clark Hot Water Extraction (CHWE) process, a hot water flotation process, or the like.

[0016] As referred to herein, the terms "oil sands" or "oil sands ore" refers to the raw oil sands material, including the material excavated from oil sands deposits.

[0017] In exemplary embodiments, the methods are suitable for bitumen recovery operations, for example those in the Athabasca region, wherein bitumen is produced from the surface-mineable oil sands using water-slurry-based extraction processes. In such processes the oil sands or oil sands ore may be combined with hot water to form an ore-water slurry.

Date Recue/Date Received 2022-01-26

[0018] It has been discovered that adding one or more aluminum-containing compounds to an extraction process can enhance the recovery of bitumen, in particular when extracting bitumen from low-grade oil sands ore. In addition, the one or more aluminum-containing compounds also can reduce or eliminate the release of certain toxic natural substances, for example naphthenic acids, and can improve process tailings management.

[0019] According to the various exemplary embodiments, the one or more aluminum-containing compounds may provide one or more functions in the extraction process. For example, in some exemplary embodiments, the one or more aluminum-containing compounds, when used as described herein, may alter the surface properties of fine and ultrafine solids to improve bitumen separation. In some exemplary embodiments, the aluminum-containing compounds may create an increase in froth in the bitumen recovery process. In exemplary embodiments, the aluminum-containing compounds, when used as described herein, may facilitate or enhance coagulation of fine or ultrafine solids to improve consolidation of the tailings that result from an exemplary process or other oil sand extraction process. In exemplary embodiments, the aluminum-containing compounds can be used in an exemplary process or other oil sand extraction process in the presence or absence of sodium hydroxide.

[0020] Aluminum-Containing Compounds

[0021] In exemplary embodiments, the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate, aluminum sulfate, aluminum hydroxide sulfate, aluminum chloride, sodium aluminate, polyaluminum sulfate, polyaluminum silicate chloride, polyaluminum chloride, polyaluminum sulfate chloride, polyaluminum ferric sulfate, polyaluminum ferric chloride, polyaluminum calcium silicate sulfate, aluminum chlorohydrate, an aluminum ferric sulfate blend, an aluminum ferric chloride blend, a blend of polyaluminum chloride, aluminum chlorohydrate, another aluminum-containing coagulant, or mixtures thereof. In exemplary embodiments, the one or more aluminum-containing compound comprises an aluminum sulfate such as acidified aluminum sulfate, prehydroxylated aluminum sulfate or granulated aluminum sulfate. In certain embodiments, the one or more aluminum-containing compounds comprises polyaluminum silica sulfate. In certain embodiments, the one or more aluminum-containing compounds comprises aluminum hydroxide sulfate. In exemplary embodiments, the one or more aluminum-containing compounds comprises one or more aluminum-containing coagulants. In exemplary embodiments, the one or more aluminum-containing compounds are selected from the group consisting of aluminum-containing coagulants. In certain embodiments, the one or more aluminum-containing compounds does not comprise polyaluminum chloride.

[0022] In exemplary embodiments, the aluminum-containing compound may be used in combination with one or more non-aluminum-containing coagulants.
Exemplary coagulants include, for example, polydiallyldimethylammonium chloride coagulant or an epiamine coagulant.

[0023] In exemplary embodiments, the one or more aluminum-containing compounds are in solid form, liquid form or in the form of a suspension, including, for example, a dry powder or a suspension-in-water.

[0024] Bitumen Recovery/Extraction Processes

[0025] In an exemplary embodiment, a process for enhancing the efficiency of bitumen recovery from oil sands ore comprises adding water and one or more aluminum-containing compounds to the oil sands ore which contains bitumen.

[0026] In one embodiment, a process for recovering bitumen from oil sands ore includes: (i) adding one or more aluminum-containing compounds to an oil sands ore-water slurry; and (ii) liberating bitumen.

[0027] In another embodiment, a process for extracting bitumen from oil sands ore includes: (i) mixing oil sands ore with water or an aqueous solution to form a slurry; (ii) aerating or conditioning the slurry to form a froth containing bitumen within the slurry; (iii) separating the froth from the slurry: (iv) adding one or more aluminum-containing compounds to the slurry prior to or during one or more of the preceding steps;
and (v) liberating bitumen from the froth.

[0028] In exemplary embodiments, the one or more aluminum-containing compounds may be added in any mixing, conditioning, or separation step in the bitumen recovery process. In view of the embodiments described herein, it will be understood that the one or more aluminum-containing compounds could be added at other points in the bitumen recovery/extraction process as necessary or desired.

[0029] In exemplary embodiments, the oil sands slurry comprises bitumen, mineral solids and/or fines, and water.

[0030] In exemplary embodiments, the one or more aluminum-containing compounds may be added to the oil sand ore-water slurry during any point before or during the mixing stage. In exemplary embodiments, mixing of the ore-water slurry may be achieved by any known process or apparatus. For example, after the oil sands ores have been mined and crushed, the oil sands ores may be transported by conveyor to a slurry preparation plant, where hot water is added to make the oil sand ore-water slurry. In one embodiment, the oil sands ore may be low grade ore. In one embodiment, the oil sands ore may be high grade ore. In exemplary embodiments, the temperature of the water and/or the slurry may be any temperature as necessary or desired. In an exemplary embodiment, the temperature of the water and/or the slurry may be elevated to provide an effective amount of heat to the slurry to substantially release the bitumen from the sand surface. In one embodiment, the water or aqueous solution used in the process may be between at a temperature of about 0 C
to about 100 C; 0 C to about 90 C; about 20 C to about 90 C; about 40 C to about 90 C; or about 40 C to about 60 C. In exemplary embodiments, the temperature of the slurry may be maintained at about 40 C to about 60 C. Depending, for example, on the temperature of the water, and/or the availability of thermal energy in the process, the temperature of the slurry may be elevated to the necessary or desired process temperature. In the exemplary embodiments, the one or more aluminum-containing compounds may be added to the slurry before or during any of the mixing and conditioning stages described above, or their respective equivalents.

[0031] In exemplary embodiments, the process further comprises heating the slurry in an amount effective to substantially liberate the bitumen.

[0032] In one embodiment, the one or more aluminum-containing compounds may be added to the oil sand ore-water slurry during any point before or during a conditioning stage. Conditioning of the slurry, as described herein, may include further mixing or churning of the slurry, aeration of the slurry to form a froth, breaking of lumps in the slurry into smaller lumps, liberation of bitumen from sand grains, breaking of bitumen into smaller droplets, attaching liberated bitumen droplets to air bubbles, mixing the slurry with optional additives and other process aids, or the like. Generally, the effect of the conditioning stage is to enhance or maximize the liberation of bitumen from the sand grains and separation of bitumen or the froth containing bitumen from the slurry. Conditioning of the slurry may be achieved by any means known in the art and is not limited to the embodiments described herein.

[0033] In exemplary embodiments, after the slurry has been prepared and mixed, the ore-water slurry may be conditioned by any known process or apparatus. For example, after the slurry is formed, the slurry may be transported through a slurry hydrotransport pipeline, which may be used to condition the slurry. In the slurry hydrotransport pipeline, the hydrodynamic forces from speed of the slurry may liberate bitumen from the sand grains, break the liberated bitumen into smaller droplets, and promote attachment of the liberated bitumen droplets to entrained air bubbles. In exemplary embodiments, the size, shape, configuration, and length of the hydrotransport pipeline may be predetermined to provide any necessary or desired results. For example, the length of the hydrotransport pipeline may be determined, at least in part, based on the processing plant location, the slurry temperature, the initial lump size, or other conditions that may affect the conditioning of the slurry. In some embodiments, the hydrotransport pipeline may be up to about 5 kilometers. The speed of the slurry through the hydrotransport pipeline may be predetermined to provide any necessary or desired result. For example, in an exemplary process, the slurry is transported through the pipeline at about 3 to about 5 meters per second. In the exemplary embodiments, the one or more aluminum-containing compounds may be added before or during any of the mixing and conditioning stages described above, or their respective equivalents.
100341 Aerating the slurry (or a derivative of the slurry) may be achieved by any means known in the art. In exemplary embodiments, aerating the slurry promotes the formation of froth and may be achieved, for example by mixing or churning the slurry in a mixing or transport vessel or apparatus, such as the transport of the slurry in a slurry hydrotransport pipeline. In some embodiments, the slurry or a derivative thereof may be aerated, for example, by sparging the slurry or derivative thereof in a vessel or apparatus (e.g., during the secondary separation process, described below). In one embodiment, the one or more aluminum-containing compounds may be added to the oil sand ore-water slurry (or any derivative thereof) before or during any extraction process. As used herein, an "extraction" process may include any process step or stage that furthers the liberation, separation, or isolation of bitumen from the other components of the oil-water slurry or its derivatives.
[0035] In one embodiment, the one or more aluminum-containing compounds may be added to the oil sand ore-water slurry (or any derivative thereof) before or during a primary separation process. As referred to herein, the "primary separation process" is the first separation of bitumen froth from solids after the oil sands ore-water slurry is formed and conditioned. In exemplary embodiments, primary separation of the bitumen froth from the solids may be accomplished by any known process or apparatus. For example, at the end of the slurry hydrotransport pipeline, the conditioned slurry may be discharged to one or more large stationary primary separation cells (PSC) or vessels (PSV). In the PSC, the aerated bitumen may float through the slurry upwards to the top of the cell where it may overflow, and be collected as primary bitumen froth. Within the PSC, the coarse solids may settle, forming a dense slurry at the bottom of the PSC which can be removed from the bottom of the PSC as "tailings- stream. Within the PSC, fine solids with some un-aerated fugitive fine bitumen droplets may remain suspended in the slurry. This low-density slurry may be removed from the middle of the separation cell as a "middlings" stream. In various embodiments, the one or more aluminum-containing compounds may be added before or during any of the primary separation stages described herein, or their respective equivalents.
For example, the one or more aluminum-containing compounds may be added to the oil sand ore-water slurry in the PSC.
[0036] In exemplary embodiments, one or more of the streams from the primary separation processes may optionally undergo further processing to further the bitumen separation and isolation from the other components of the streams. These processes are referred to as "secondary separation processes." In exemplary embodiments, the one or more aluminum-containing compounds may be added to the slurry or any derivative thereof in a secondary separation process. For example, the middlings stream may be further processed using flotation technology to enhance bitumen-air attachment. An exemplary flotation technology may be, for example, mechanical flotation process or a flotation column in which air is added to enhance bitumen-air attachment. In this flotation process, middlings may be subjected to vigorous agitation and aeration, and the aerated fine bitumen droplets may be recovered as secondary bitumen froth. The secondary bitumen froth may be returned to the PSC for further cleaning or sent with the primary bitumen froth from PSC to a subsequent bitumen froth cleaning stage. In exemplary embodiments, the tailings stream from the PSC
may be further processed, for example, in a tailings oil recovery (TOR) unit.
The TOR may include a secondary separation cell or a flotation cells for further recovery of bitumen from the tailing stream. In the secondary separation processes, additional air or water may be added to the process streams to further enhance the separation or isolation of bitumen. In the embodiments, one or more aluminum-containing compounds may be added to the slurry or process streams thereof to further enhance the separation or isolation of bitumen from these streams.
[0037] In exemplary embodiments, the streams from separation processes may optionally undergo additional processing to further the bitumen separation and isolation. For example, the primary separation process and/or the secondary separation process, or any of the steps related thereto may be repeated in order to achieve the necessary or desired result.
In the exemplary embodiments, the one or more aluminum-containing compounds may be used in these additional processing steps to further the bitumen separation and isolation.

[0038] In exemplary embodiments, the one or more aluminum-containing compounds may be added to froth underwash water entering a PSC. Addition of the one or more aluminum-containing compounds into the froth underwash water may allow for a portion of the fines and clays carried up into the froth layer to be coagulated and rejected from the froth, improving its quality. The one or more aluminum-containing compounds added to the underwash water may cause the fines and clays carried up with the bitumen to coagulate and fall away from the bitumen froth, separating them from the middlings and improving the quality of the middlings stream. In exemplary embodiments, the treatment of froth underwash with the one or more aluminum-containing compounds can be used to reduce the solids content in the froth and also to reduce the water content in the froth. In exemplary embodiments, the one or more aluminum-containing compounds are fed to the PSC with the underwash feed water, for example, by injection pump. Any suitable injection pump or other method of introducing the aluminum-containing compound to the underwash may be used. It can be fed at room temperature, however the underwash feed water is typically ca. 80 C. but generally ranges from about 20 C. to about 90 C.
[0039] In exemplary embodiments, a process for improving froth quality and bitumen recovery from an oil sands slurry comprises: (i) introducing the oil sands slurry into a primary separation cell; (ii) contacting an underwash water with the oil sands slurry, wherein the underwash water comprises an effective amount of one or more aluminum-containing compounds; and (iii) allowing the oil sands slurry to separate into a froth layer and a middlings layer, wherein the froth layer comprises a lower mineral solids content than would be present without the addition of the one or more aluminum-containing compounds in the underwash water.
[0040] In certain embodiments, the one or more aluminum-containing compounds can be used to replace some or all of the sodium hydroxide or other process aid chemicals in a process for recovering bitumen from oil sands ore. In one embodiment, the process does not comprise the addition of any sodium hydroxide or other process aid chemicals other than the one or more aluminum-containing compounds.
[0041] In the exemplary embodiments, the one or more aluminum-containing compounds may be added to the oil sands slurries as a dry powder or as a suspension in water.
[0042] In exemplary embodiments, the one or more aluminum-containing compounds may be added to the oil sands ore-water slurry (or any process streams derived therefrom) in any amount to provide a necessary or desired result. For example, the dosage of one or more aluminum-containing compounds may be the amount effective to provide the maximum yield of bitumen at that point in the process. In exemplary embodiments, the one or more aluminum-containing compounds may be added in a broad range of dosages without adversely impacting bitumen extraction or release water chemistry. In exemplary embodiments, the dosage of the one or more aluminum-containing compounds may be that which is effective to reduce the attraction between clay particles and bitumen, thereby promoting the detachment of clay particles from bitumen droplets in an oil sands ore-water slurry.
[0043] In exemplary embodiments, the dosage of the one or more aluminum-containing compounds added to the oil sands ore-water slurry or process streams derived therefrom is in the range of about 10 to about 10000 grams one or more aluminum-containing compounds per dry ton (g/t) of ore (e.g., for the slurry) or of dry suspended solids (e.g., for other process streams). In some embodiments, the dosage of the one or more aluminum-containing compounds is from about 100 to about 5000 g/t, about 100 to about 2000 g/t, about 50 to about 1700 g/t, about 100 to about 1600 g/t, about 500 to about 1150 g/t, or about 500 to about 1000 g/t. In one embodiment, the dosage of the one or more aluminum-containing compounds is about 100 g/t, about 150 g/t, about 200 g/t, about 250 g/t, about 300 g/t, about 350 g/t, about 400 g/t, about 450 g/t, about 500 g/t, about 550 g/t, about 600 g/t, about 650 g/t, about 700 g/t, about 750 g/t. about 800 g/t, about 850 g/t, about 900 g/t, about 950 g/t, about 1000 g/t, about 1050 g/t, about 1100 g/t, about 1150 g/t, about 1200 g/t, about 1250 g/t, about 1300 g/t, about 1350 g/t, about 1400 g/t. about 1450 g/t, about 1500 g/t, about 1550 g/t, about 1600 g/t, about 1650 g/t, about 1700 g/t, about 1750 g/t, about 1800 g/t, about 1850 g/t, about 1900 g/t, about 1950 g/t, or about 2000 g/t.
100441 In one embodiment, after addition of the one or more aluminum-containing compounds, the one or more aluminum-containing compounds are permitted to remain in contact with the oil sands ore-water slurry (or process streams derived therefrom) for a predetermined amount of time prior to separation of the bitumen. In some embodiments, the one or more aluminum-containing compounds remain in contact with the oil-water slurry or a process stream for about 10 minutes to about 180 minutes, about 15 minutes to about 120 minutes, about 20 minutes to about 90 minutes, or about 20 minutes to about 60 minutes prior to the separation of the bitumen. In some embodiments, the one or more aluminum-containing compounds remain in contact with the oil-water slurry or a process stream for at least about 20 minutes, at least about 30 minutes, at least about 40 minutes, at least about 50 minutes, or at least about 60 minutes, prior to the separation of the bitumen.

[0045] In certain embodiments, the processes may recover at least about 5%, about 10%, about 20%, about 30%, about 40%, or about 50% more bitumen than comparable processes using sodium hydroxide or lime.
[0046] In one embodiment, at least about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95% of the total organic compounds or bitumen are extracted in the primary and secondary separation steps of the processes described herein.
[0047] In any of the exemplary embodiments, the slurry (or process streams derived therefrom) may further include any additive or other process aid, such as a surfactant, an anti-foaming agent, a polymer, a flocculent, a mineral oil or a mixture thereof. In one embodiment, the additives are in an amount of 0.01 to 10 weight percent based on the total weight of the composition.
[0048] The following examples are presented for illustrative purposes only, and are not intended to be limiting.
EXAMPLES
[0049] Example 1. Effect of Dosage of Exemplary Aluminum-Containing Compound on Bitumen Recovery Rate Using a Denver Flotation Cell [0050] In this example, the effect of dosage of polyaluminum silicate sulfate (available from Kemira Oyj) on bitumen recovery rate was examined in an experiment using 0, 1000 or 2000 g/t of polyaluminum silicate sulfate on a low-grade oil sands sample from Alberta, Canada. The bitumen, water, and solids content of the ore was determined by Dean-Stark extraction to be 8.33%, 4.82%, and 86.84%, respectively.
[0051] The experiments were conducted in a laboratory scale Denver flotation cell (Metso Minerals, Danville, PA) under semi-batch conditions (batch water, continuous air). In a typical experiment, 300 g of oil sand ore was added to 1.5 Liter of pre-heated water at 50 C
at the impeller speed of 1000 rpm in a 2 Liter rectangular cell. The flotation cell was kept at 50 C by using a hot water circulating bath. The slurry was conditioned at these conditions for 5 min. The slurry was then subjected to air bubble flotation using an airflow rate of 200 ml/min. Froth samples were collected at time intervals of 2, 5, 10, 20 and 60 after flotation started while agitation was paused for 30 sec. Bitumen recovery rates, solid and water contents were determined using Dean-Stark Soxhlet extractor units with toluene solvent.
[0052] Figure 1 shows the bitumen recovery data as a function of time for low grade ore samples treated by polyaluminum silicate sulfate. As shown in Figure 1, the use of polyaluminum silicate sulfate improves the liberation of bitumen from sand.

[0053] Example 2. Effect of Dosage of Exemplary Aluminum-Containing Compound on Bitumen Recovery Rate Using a Batch Extraction Unit [0054] In this example, the effect of polyaluminum silicate sulfate on bitumen recovery rate was examined in a batch extraction unit (BEU) using 250 g/t of polyaluminum silicate sulfate on a medium-grade oil sands samples from Alberta, Canada. The bitumen, water, and solids content of the ore was determined by Dean-Stark extraction to be 9.76%, 5.23%, and 85.01%, respectively.
[0055] For each test, 500 g of oil sand, 150 mL of process water (50 C), and additive (if necessary) were added to the BEU. Water was circulated through the jacket of the BEU at 52 C to maintain temperature. The impeller speed was set to 600 rpm and the slurry conditioned at these conditions for 10 minutes as air was injected at a rate of 150 mL/min. The aeration was then turned off and an additional 850 mL of process water was added to the tank. The slurry was conditioned for an additional 5 minutes, at which point the impeller was stopped and the primary froth was skimmed off the top. The slurry was conditioned for an additional 5 minutes at an impeller speed of 780 rpm and an aeration rate of 50 mL/min. The impeller and aeration were then stopped and the secondary froth was skimmed in the same manner as the primary froth. Bitumen, solid, and water contents of the froths were determined by using Dean-Stark soxhlet extraction units with toluene.
[0056] Figure 2 shows the bitumen recovery data as a function of time for medium grade ore samples treated by polyaluminum silicate sulfate. As shown in Figure 2, the use of polyaluminum silicate sulfate improves the liberation of bitumen from sand.
100571 In the preceding specification, various exemplary embodiments have been described. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the exemplary embodiments as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.

Claims (20)

We Claim:

1. A process for recovering bitumen from oil sands ore, comprising:
(i) adding one or more aluminum-containing compounds to an oil sands ore-water slurry wherein the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate; and (ii) liberating bitumen.

2. A process for recovering bitumen from an oil sand ore, comprising:
(i) mixing oil sands ore with water or an aqueous solution to form a slurry;
(ii) aerating the slurry to form a froth containing bitumen within the slurry;
(iii) separating the froth from the slurry;
(iv) adding one or more aluminum-containing compounds to the slurry prior to or during one or more of the preceding steps wherein the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate; and (v) liberating bitumen from the froth.

3. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds are added to the slurry during a hot water extraction process.

4. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds are in solid form.

5. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds are in liquid form.

6. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds are in the form of a suspension.

7. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds is added to the slurry in a slurry transportation pipeline.

Date Recue/Date Received 2022-01-26

8. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds in added to the slurry in a primary separation vessel.

9. The process of any one of claims 1 or 2, wherein the one or more aluminum-containing compounds is added to the slurry in a secondary separation vessel.

10. The process of any one of claims 1 or 2, wherein the dosage of the one or more aluminum-containing compounds is in the range of about 10 to about 10000 grams one or more aluminum-containing compounds per dry ton ore.

11. The process of any one of claims 1 or 2, wherein the dosage of the one or more aluminum-containing compounds is in the range of about 100 to about 2000 grams one or more aluminum-containing compounds per dry ton ore.

12. The process of any one of claims 1 or 2, wherein the dosage of the one or more aluminum-containing compounds is in the range of about 500 to about 1000 grams one or more aluminum-containing compounds per dry ton ore.

13. The process of any one of claims 1 or 2, wherein the process further comprises heating the slurry in an amount effective to liberate the bitumen.

14. The process of claim 2, wherein the water or aqueous solution is at a temperature of about 0 C to about 90 C.

15. The process of any one of claims 1 or 2, wherein the temperature of the slurry is maintained at about 40 C to about 60 C.

16. The process of any one of claims 1 or 2, wherein the process further comprises transporting the slurry through a slurry hydrotransport pipeline.

17. A process for improving froth quality and bitumen recovery from an oil sands slurry comprising:
(i) introducing the oil sands slurry into a primary separation cell;
Date Recue/Date Received 2022-01-26 (ii) contacting an underwash water with the oil sands slurry, wherein the underwash water comprises an effective amount of one or more aluminum-containing compounds, wherein the one or more aluminum-containing compounds comprises polyaluminum silicate sulfate; and (iii) allowing the oil sands slurry to separate into a froth layer and a middlings layer, wherein the froth layer comprises a lower mineral solids content than would be present without the addition of the one or more aluminum-containing compounds in the underwash water.

18. The process of claim 17, wherein the one or more aluminum-containing compounds are in solid form.

19. The process of claim 17, wherein the one or more aluminum-containing compounds are in liquid form.

20. The process of claim 17, wherein the one or more aluminum-containing compounds are in the form of a suspension.

Date Recue/Date Received 2022-01-26