CA1334584C

CA1334584C - Use of a revolving drum with oleophilic internal surfaces to increase the particle size of bitumen phase in an aqueous mixture

Info

Publication number: CA1334584C
Application number: CA 604527
Authority: CA
Inventors: Jan Kruyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-06-30
Filing date: 1989-06-30
Publication date: 1995-02-28
Anticipated expiration: 2012-02-28

Abstract

A revolving drum containing a multitude of oleophilic mechanical surfaces in fixed relationship with the inside drum walls is used to increase the particle size of bitumen phase in an aqueous mixture. The mixture tumbles in the drum and the mechanical surfaces, passing through the mixture, capture bitumen phase particles that accumulate on these surfaces and increase in size until they are sloughed off these surfaces back into the mixture in the form of enlarged bitumen phase particles. When the water phase of the mixture is relatively low in minerals content, the revolving drum and its mechanical surfaces are used to transfer water wetted mineral particles from the bitumen phase to the aqueous phase of the mixture, resulting in a bitumen phase with reduced minerals content.

Description

The present invention relates to the recovery of bitumen and bitumen wetted minerals from a mixture of bitumen, water, bitumen wetted minerals and water wetted minerals.
This invention is primarily concerned with increasing the particle size of bitumen and bitumen wetted minerals in mixtures from mined oil sands, from tailings of mined oil sands plants, from tailings pond sludge of mined oil sands plants, from heavy oil, water and minerals mixtures of oil wells, from bitumen and water mixed with ore of mineral mines and from bitumen and water mixed with materials of placer deposits. The invention is particularly concerned with making it easier to recover bitumen and bitumen wetted minerals from such mixtures. The invention is also concerned with making it easier to recover residual bitumen and bitumen wetted minerals from such mixtures after an initial amount of bitumen and bitumen wetted minerals have previously been recovered from such mixtures.
The invention is also concerned with removing hydrophilic minerals from the bitumen phase of mixtures of bitumen, bitumen wetted minerals and water wetted minerals with an excess of water.
Extensive deposits of oil sands, which are also known as tar sands or bituminous sands, are found in Northern Alberta Canada and in many other parts of the world including the USA, Venezuela, and in various countries of Africa and Asia, including the USSR.
The sands are composed of siliceous material with grains generally having a size greater than that passing a 325 mesh screen (44 microns) and a relatively heavy viscous petroleum called bitumen, which at least partly fills the voids between the grains in quantities from 2 to 25 percent of total composition. (All ~'.

133~584 -- percentages referred herein are in weight percent unless noted otherwise) Generally the bitumen content of sand that is mined commercially is between 8 and 15 percent. This bitumen contains typically 4.5 percent sulfur and 38 percent aromatics. Its specific gravity at 15 degrees C. ranges generally from about 1.0 to about 1.1. The oil sands also contain clay and silt. Silt is defined as siliceous material which will pass a 325 mesh screen, but which is larger than 2 microns. Clay is material smaller than 2 microns, including some siliceous material of that size. In some cases the oil sands also contain a small percentage of heavy minerals including ilmenite, rutile, zircon and other metallic minerals.
Much of the world resource of bitumen and heavy oil is deeply buried by overburden. For example it has been estimated that less than 10 percent of the Alberta oil sand deposit is close enough to the earth s surface to be conveniently recovered by surface mining.
The remainder is buried too deeply to be economically strip mined with current technology. Hydraulic mining has been proposed for those deposits. Generally, however, it is considered that enhanced recovery by steam injection, by injection of aqueous solutions, or by in-situ combustion may possibly be more effective for obtaining bitumen from deeply buried formations.
Such enhanced recovery methods use one or more oil wells that penetrate the formation and stimulate the flow of bitumen or heavy oil to a recovery well. In some cases, the same well may be used to stimulate and recover the resource. Depending upon the procedure employed, enhanced recovery methods generally produce mixtures of water, bitumen and some sand and minerals and they recover a lower percentage of the bitumen in place than mining methods.

- 133458~

~ There are several well known procedures for separating bitumen from mined oil sands. In a hot water process, such as disclosed in Canadian Patent No.
841,581 issued 12 May 1979 to Paul H. Floyd et al.; the bituminous sands are jetted with steam and mulled with a minor amount of hot water and sodium hydroxide in a conditioning drum to produce a pulp which passes from the conditioning drum through a screen, which removes debris, rocks and oversize lumps, to a sump where it is diluted with additional water. It is hereafter carried into a separation cell. In the separation cell, sand settles to the bottom as primary tailings which are discarded. Bitumen rises to the top of the cell in the form of a bituminous froth which is called the primary froth product. An aqueous middlings layer containing some mineral and bitumen is formed between these layers. A scavenging step is normally conducted on this middlings layer in a separate flotation zone. In this scavenging step the middlings are aerated so as to produce a secondary tailings product, which is discarded, and a secondary froth product.
The secondary froth product is treated to remove some of its water and mineral matter content and is thereafter combined with the primary froth for further treatment. This combined froth typically contains about 52 percent bitumen, 6 percent minerals, 41 percent water, all by weight, and may contain from 20 to 70 volume percent air. It resembles a liquid foam and is usually treated with steam to improve its flow characteristics for subsequent processing. The primary and secondary tailings products are usually combined and water may be added to enhance the pipeline disposal of this combined tailings stream called the extraction tailings.
The high water and minerals contents of the combined froth product normally are reduced by diluting 133458~
it with hydrocarbon diluent such as naphtha. It is then centrifuged to produce a tailings product, called the centrifugal tailings, and a final bitumen product that typically contains essentially no water and less than 1.0 percent solids. The naphtha is recovered from the final bitumen product which then is suitable for coking, hydrovisbreaking or other refining techniques to produce a synthetic crude oil. The centrifugal tailings, containing some naphtha, bitumen, silt, clay and heavy minerals are discarded.
There are basically three effluent streams from the hot water process. Each carries with it some of the bitumen from the feed; thereby reducing the efficiency of the process. These include the oversize materials coming from the screen, the extraction tailings and the centrifugal tailings. Up to 10 percent of the bitumen in the original feed and up to 2.5 percent of the naphtha stream may be lost in this manner. Much of this lost bitumen finds its way into large retention ponds or tailings ponds that are typical of the hot water process. The bottom of such retention ponds may contain from 20 to to 50 percent dispersed mineral matter substantially of clay and silt as well as 2 percent or more bitumen. As disclosed in Canadian Patent No. 975,697 issued on 7 October 1975 to David H. James this part of the pond contents, referred to as sludge, or tailings pond sludge, is a potential source of recoverable bitumen.
In the hot water process the heavy minerals present in the oil sand ore tend to be attracted to and wetted by the bitumen of the oil sands during processing, and these heavy minerals are recovered in the combined bitumen froth product. The minerals are removed from this bitumen product in the dilution centrifuging step and are part of the centrifugal tailings of the hot water process.

I have found that the extraction tailings from the hot water process contain heavy minerals as well.
These heavy minerals are in association with and are wetted by the bitumen that is discarded with the extraction tailings. I have discovered that this residual bitumen generally contains a higher percentage of heavy minerals than the bitumen froth produced by the hot water process. I have concluded that most of the bitumen that remains with the extraction tailings of the hot water process is there for a reason. It is there because this bitumen does not float as readily as the bitumen that is recovered. The increased amount of minerals associated with this bitumen make it denser and more difficult to float than the bitumen that is normally recovered in the flotation steps of the hot water process. Then, when this residual bitumen is recovered from these extraction tailings, by an apertured oleophilic belt separation process, which does not rely on flotation alone, the resulting bitumen product contains a large amount of heavy minerals.
When Alberta oil sands are mixed with water and are separated with an apertured oleophilic belt, the bitumen product contains heavy minerals which are bitumen wetted and the water phase contains sand, silt and clay that are water wetted. When extraction tailings from a hot water process are separated with an apertured belt to recover the residual bitumen, the bitumen product from that separation contains heavy minerals which are bitumen wetted and the water phase contains sand, silt and clay that are water wetted.
Similarly, when tailings pond sludge is separated with an apertured belt, the bitumen product from that separation contains heavy minerals which are bitumen wetted and the water phase of the sludge contains silt and clay that are water wetted. Therefore, when a mixture is separated with an apertured oleophilic belt, the bitumen wetted minerals are recovered along with the bitumen phase and the water wetted minerals are discarded with the water phase. As more bitumen is recovered from such a mixture, more heavy minerals are recovered from the mixture as well.
The present invention serves to assist in recovering bitumen and also to assist in concentrating heavy minerals from a mixture by capturing these with the bitumen product. These minerals are released when the bitumen product is diluted and centrifuged, or when the bitumen is removed from these minerals in some other way. Heavy minerals are found in small concentration of about 1% in the Alberta oil sands.
Oil sands from other locations may contain traces of other types of minerals, including gold, silver, platinum and other useful or precious minerals. These minerals in many cases are or become bitumen wetted in the process of the present invention and are recovered with the bitumen. They can be separated from that bitumen to yield a minerals by-product of the extraction process.
The present invention may also be used to assist in recovering useful minerals from other ores. Bitumen and water may be mixed with ore from a mine to cause the minerals of the ore to become bitumen wetted while the gangue becomes water wetted. In a subsequent separation by an apertured oleophilic belt of this ore-bitumen-water mixture, the resulting bitumen product will contain bitumen wetted mineral of the ore for recovery, and the water effluent will contain water wetted gangue of the ore to be discarded. On other occasions bitumen and, if required, water may be mixed with a placer deposit of minerals, metals or precious stones to cause these to become bitumen wetted and the gangue to remain water wetted. In subsequent separation, by the apertured oleophilic belt of this 133458~
placer deposit mixture, the resulting bitumen product will contain bitumen wetted minerals, metals or precious stones of the placer deposit for recovery, and the water effluent will contain water wetted gangue of the placer deposit for disposal. The useful minerals, metals or stones are subsequently recovered by removing bitumen from the product and/or by burning off the residual carbon. The resulting minerals residue may then be separated into components by mineralogical methods. The mineral recovery aspects of the present invention may in time be used in combination with an apertured oleophilic belt to compete with conventional minerals froth flotation, with the added advantage that mineral particles of larger size may be recovered more efficiently.

OBJECTIVES OF THE PRESENT INVENTION

The present invention applies to a method for recovering bitumen and bitumen wetted minerals from a mixture of bitumen, water, water wetted minerals and bitumen wetted minerals with an apertured oleophilic endless moving belt. The invention specifically applies to a method for increasing the size of bitumen particles and bitumen wetted mineral particles in said mixture to improve primary recovery of these particles by an apertured oleophilic endless moving belt. The present invention also applies to a method for increasing the size of bitumen particles and bitumen wetted particles in said mixture to improve secondary recovery of these particles by an apertured oleophilic endless moving belt. The present invention further applies to the removal of hydrophilic minerals from bitumen in mixtures of bitumen, bitumen wetted minerals, water and water wetted minerals.

When a mixture of bitumen, bitumen wetted minerals, water and water wetted minerals comes in contact with the surfaces of an apertured oleophilic endless moving belt, these surfaces capture particles of bitumen and bitumen wetted minerals from this mixture in a separation zone, while water and water wetted minerals flow through the belt apertures. These captured bitumen and bitumen wetted mineral particles accumulate on the belt in the form of a bitumen phase and are carried or conveyed continuously by the moving belt from the separation zone to a recovery zone where bitumen phase is removed from the belt.
When these bitumen particles and these bitumen wetted and bitumen coated mineral particles are very small, they are less likely to come in contact with the surfaces of the apertured oleophilic belt, and more likely to pass through the apertures, than when they are large. It is an objective of the present invention to increase the particle size of these bitumen particles and of these bitumen wetted mineral particles so that the likelihood is improved of them being captured by the apertured oleophilic endless moving belt, in a first pass through the belt.
When a mixture of bitumen, water, water wetted minerals and bitumen wetted minerals mixture is passed to an apertured oleophilic endless moving belt, without the mixture having been treated to thus increase the particle size, the mixture that passes through the apertures of such a belt may contain a considerable number of small bitumen particles and small bitumen wetted mineral particles. It is a further objective of the present invention to increase the size of these small bitumen particles and of these small bitumen wetted mineral particles so that they are more easily recovered when this mixture containing these particles 133~584 is passed through an apertured oleophilic endless moving belt for the second time.
Furthermore, a bitumen product, containing bitumen, bitumen wetted minerals, water wetted minerals and an excess of water, may be processed by the method of the present invention to remove water wetted minerals from the bitumen phase and improve the quality of the bitumen phase that is subsequently separated from the mixture with an apertured oleophilic belt.
BRIEF DESCRIPTION OF THE INVENTION

The present invention applies to a method of increasing the particle size of bitumen particles and of bitumen wetted minerals particles of a mixture of water, bitumen, bitumen wetted minerals and water wetted minerals by contacting these particles in a novel way with oleophilic surfaces in a revolving drum.
In one aspect, the invention provides a method for increasing the mean particle size of bitumen and bitumen wetted mineral particles in a feed mixture of bitumen, water, bitumen wetted minerals, and water wetted minerals, which comprises the steps of:
a) introducing said feed mixture into a rotating drum that contains an abundance of oleophilic mechanical surfaces, said drum rotating at a rate not exceeding the critical rotation rate and said oleophilic surfaces rotating in fixed relationship with the walls of said drum, b) tumbling said mixture in the rotating drum so that said oleophilic surfaces continually pass through said mixture and come in contact with said bitumen particles and with said bitumen wetted mineral particles causing said particles to unite to form bitumen phase particles that are larger in size than 13~4584 the particles of bitumen in the feed mixture initially introduced into said drum, and c) removing tumbled mixture containing said enlarged bitumen phase particles from said drum.
Increasing the size of the bitumen particles renders the mixture more suitable for subsequent separation of bitumen phase from aqueous phase with an apertured oleophilic endless moving belt or with an apertured oleophilic moving wall.
In another aspect the invention provides a method for removing water wetted minerals from the bitumen phase of a feed mixture consisting of bitumen, bitumen wetted minerals,water wetted minerals and which comprises the steps of:
a) introducing said feed mixture into a rotating drum that contains an abundance of oleophilic surfaces, said drum rotating at a rate not exceeding the critical rotation rate and said oleophilic surfaces rotating in fixed relationship with the walls of said drum, b) tumbling said feed mixture in the rotating drum with said oleophilic surfaces causing water wetted minerals in the bitumen phase of the mixture to be exposed and causing these minerals to become part of the aqueous phase of said mixture, c) separating said tumbled mixture with an apertured oleophilic endless moving belt or with an apertured oleophilic moving wall into a bitumen phase product and an aqueous phase effluent. As a consequence of the tumbling the bitumen phase product contains a lower percentage of minerals than the bitumen phase of the feed mixture that enters said drum.
In yet another aspect the invention provides an apparatus for increasing the mean particle size of bitumen and bitumen wetted mineral particles in a feed mixture of bitumen, water, bitumen wetted minerals and 133~584 water wetted minerals, or for removing water wetted minerals from the bitumen phase of such a feed mixture in the presence of extra water, which apparatus comprises:
a) a generally horizontal rotatable drum containing an abundance of mechanical oleophilic surfaces that are in fixed relationship with the inside walls of said drum, b) a means for entry of feed mixture into said drum and a means for exit of tumbled mixture from said drum.
c) a means for rotating said drum and a means for supporting said rotatable drum In the present invention the oleophilic surfaces are attached to the drum interior and/or revolve in fixed relationship with the drum interior walls and continually pass through the mixture as the drum revolves. The mixture comes in intimate contact with these oleophilic surfaces. The bitumen particles and the bitumen wetted mineral particles adhere to said surfaces until they have accumulated in sufficient thickness that the forces in the drum cause flow or sloughing off of enlarged bitumen particles and enlarged bitumen wetted mineral particles from these oleophilic surfaces. These enlarged particles returning to the mixture may contact other bitumen and bitumen wetted mineral particles and other oleophilic surfaces and adhere to them as the mixture passes through the drum. The mixture, containing enlarged bitumen particles and enlarged mineral particles, emerging from the drum, is more readily separated into a bitumen phase and a water phase with an apertured oleophilic endless belt than the mixture that enters this drum.
In one preferred form the process of the present invention may be used to increase the bitumen and 13~1584 ~ bitumen wetted minerals particle size prior to a primary separation with the apertured oleophilic endless belt. In another preferred form it may be used to increase the bitumen and bitumen wetted minerals particle size of a mixture that has already passed through an apertured oleophilic endless belt so that more bitumen and bitumen wetted minerals can be recovered from the mixture when it is passed to an apertured oleophilic belt for the second time.
In another preferred embodiment of the invention, the bitumen phase of a feed mixture is tumbled in the drum of the present invention in the presence of sufficient water. The resulting adhesion of bitumen phase of this mixture to the oleophilic surfaces in the drum and the shedding, flow or sloughing off of bitumen from these surfaces in the revolving drum serve to expose water wetted minerals present in this bitumen phase and cause these to transfer from the bitumen phase to the water phase for subsequent separation by an apertured oleophilic endless belt.

DRAWINGS

The invention will be further illustrated with reference to the accompnaying drawings showing, by way of example, embodiments of the invention, in which:
Figure 1 is a perspective view of a typical drum of the present invention.
Figure 2 is in inside view of a typical drum of the present invention using a charge of tightly packed oleophilic column packings to provide the oleophilic surfaces of the invention.
Figure 3 is an inside view of a typical drum of the present invention using oleophilic ropes or rods on a structure inside the drum to provide the oleophilic surfaces of the invention.

-Figure 4 is a crosæ sectional view of the drum of Figure 3 to show the grating supports and the location of oleophilic ropes or rods of the present invention.
Figures 5 and 6 are illustrations of how the oleophilic ropes of the present invention are attached to the grating supports.
Figure 7 is a cross sectional view of a typical rotary seal for permitting mixture to enter or leave the revolving drums of the present invention.
Figure 8 is a cross sectional view of a drum with an apertured cylindrical wall, around which is placed an apertured oleophilic endless belt.
Figure 9 is a side view of the drum of Figure 8, and Figure 10 is a detail drawing of a section of the cylindrical drum wall and the endless belt of Figure 8.
Figure 11 is a flow diagram of a typical process using the drums of the present invention.
PRIOR ART
The use of apertured oleophilic endless belts or walls to separate bitumen phase from water phase has been taught in Canadian Patents: 1,085,760 issued on 16 September 1980;
1,129,363 issued on 10 August 1982; 1,132,473 issued on 28 September 1982; 1,141,319 issued on 15 February 1983; 1,241,297 issued on 30 September 1988; 1,243,984 issued on 1 November 1988;
1,280,075 issued on 12 February 1991 and 1,288,058 issued on 27 August 1991, all to me.
The use of oleophilic free bodies to increase particle a~

- 1334584 6g606-38 size of bitumen in a revolving drum has been taught in Canadian Patents 1,144,498 issued on 12 April 1983; 1,167,792 issued on 22 May 1984; 1,241,297 issued on 30 September 1988 and 1,243,984 issued on 1 November 1988, 1,280,075 issued on 12 February 1991 and 1,288,058 issued on 27 August 1991, all to me.
In the prior art, mechanical free bodies, with oleo-philic surfaces, tumbling in a drum were used to increase the particle size of bitumen particles suspended in aqueous mixtures.
In the present invention mechanical bodies with oleophilic surfaces do not tumble in the drum but are part of the drum interior and revolve in unison with the drum walls. They are fixed with respect to the drum interior, either by attachment or by being tightly packed in the drum and prevented from tumbling by constraint of baffles, protrusions or roughness on the drum walls.
Mixtures containing water, bitumen, water wetted minerals and bitumen wetted minerals are tumbled in this drum, and oleophilic surfaces revolving in thus constrained relationship with the walls of this drum pass through the tumbling mixture due to the revolu-tions of the drum.
Thus in the prior art the particle size of bitumen particles in an aqueous mixture was increased by tumbling free bodies with the mixture in a drum, which bodies accumulated bitumen on their surfaces and then shed this accumulated bitumen back into the mixture in the drum in the form of enlarged bitumen particles. However, in the present invention the particle size of bitumen and bitumen wetted and coated minerals is increased by mechanical oleophilic surfaces in a revolving drum, that are flxed with respect to the drum interior. As these surfaces revolve through the mixture in the drum, bitumen phase accumulates on these fixed surfaces and returns back into the mixture in the form 14a .~

of enlarged bitumen phase particles. The present invention therefore uses a different mechanism to achieve similar objectives as the prior art.
During engineering scale up work of the prior art it was discovered that for use with cold mixtures, the free bodies had to have relatively high densities to achieve effective tumbling in the presence of viscous cold bitumen. It was further found that, due to the very large volumes of feedstock handled in a mined oil sands plant, the commercial size drums required for the prior art required a very large mass of heavy free bodies with commensurate high drum strength requirements, high bearing support requirements and high turning energy requirements. In the present invention the objectives of the prior art can be achieved with drums that have thinner walls, require lighter bearing supports and use less power to revolve or turn the drums.
Furthermore, the tumbling free bodies at times resulted in splashing in the drum of the prior art as free bodies fell down from the walls of the drum into the mixture, causing a redispersion and reduction of bitumen particle size in the mixture. Such splashing, due to falling mechanical bodies does not take place in the drum of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

For the purpose of the present invention, bitumen is defined as a hydrocarbon that at 15 degrees C. has a viscosity between 1,000 and 50,000,000 centipoises.
Preferably the viscosity is in the range of 10,000 to 5,000,000 centipoises, more preferably 50,000 to 1,500,000 centipoises. Bitumen may include conventional bitumen, conventional heavy oil, tar, wax, asphalt, any other thick or viscous petroleum or oil based fraction or product, or residues from land or marine oil spills.
Bitumen wetted minerals are defined for the purpose of the present invention as any number of mineral particles at least a portion of whose surface areas are oleophilic and covered by bitumen, or have become oleophilic and covered by bitumen due to exposure to bitumen and water. When the surface area portion covered by bitumen of a mineral particle is large enough to cause adhesion of this particle on contact to bitumen on a mechanical surface, such as an apertured oleophilic belt, or an oleophilic drum interior surface, the mineral particle is considered to be bitumen wetted for the purpose of the present inventlon .
Water wetted minerals are defined for the purpose of the present invention as any number of mineral particles most of whose surface areas are hydrophilic and covered with water or have become hydrophilic and covered with water due to exposure to bitumen and water, which mineral particles have no bitumen on their surfaces, or the surface portions of the particle covered by bitumen are not large enough to cause these mineral particles to adhere to bitumen on a mechanical surface on contact.
Critical rotation rate of a drum is a rate of rotation where at the apex of the drum the centrifugal force on a particle at the inside drum surface is equal to the force of gravity on that particle. This rate of rotation is a function of the radius of rotation of that particle, and hence of the inside drum diameter.
The drums of the present invention do not rotate at rates in excess of the critical rotation rate; they normally rotate a rates less than 30% of the critical rotation rate, and for most mixtures they preferably rotate at rates less than 10~ of the critical rotation 133458~
rate. Preferably the drum is at a temperature between zero and 50 degrees C., more preferably at a temperature between 10 and 30 degress C.
It is to be understood that the present invention is used to enhance the separation of bitumen and bitumen wetted minerals from water and water wetted minerals with an apertured oleophilic endless belt, no matter from where they originate. A mixture for separating, that contains bitumen, water, bitumen wetted minerals and water wetted minerals, may exist in that form; or it may be prepared as part of the separation objective prior to the actual separation.
For example, mined oil sands tailings and tailings pond sludge are mixtures that normally contain bitumen, water, bitumen wetted minerals and water wetted minerals; and these may be separated in the form they are normally produced or normally exist.
The mixture may have already passed through an apertured oleophilic endless belt before it is processed by the present invention. In that case the mixture is passed through the drum of the present invention to increase the particle size of residual bitumen and bitumen wetted mineral particles, still remaining in the water phase, to increase the likelihood that the thus enlarged bitumen and mineral particles are captured by the belt surfaces when these are introduced to a second apertured oleophilic endless belt for separation.
Oil sands, as mined, normally contain only very small amounts of water or no water at all. Water needs to be added to and mixed with such oil sands to prepare a mixture suitable for separation by the present invention. In some cases heat and/or mechanical energy needs to be added as well to the oil sands, along with the water; and this mixture needs to be tumbled and screened to digest the lumps of oil sands in water and 1~3458~
to remove debris, rocks and oversize lumps before it is prepared for separation by the present invention.
Furthermore, both water and bitumen may be added to mineral mine ores, and the resulting mixture tumbled, mixed, ground and screened before these ores are suitably prepared for separation into bitumen wetted minerals and water wetted gangue. In a similar way, bitumen and perhaps water may be added to placer deposits, tumbled and screened, and perhaps ground, before it is suitably prepared for separation into bitumen wetted minerals and water wetted gangue.
Bitumen product from a previous separation, either by froth flotation or by an apertured oleophilic belt, containing bitumen, bitumen wetted minerals, water wetted minerals, water and some extra water, may be processed by the present invention to cause the transfer of water wetted minerals from the bitumen phase to the water phase. As this mixture tumbles in the drum of the present invention the continual adhesion of bitumen to the oleophilic drum surfaces and the continual shedding of such bitumen from these drum surfaces in the presence of said mixture causes water wetted minerals, that previously were part of the bitumen phase, to be released and become part of the water phase. When this mixture is then separated subsequently by an apertured oleophilic endless belt, the resulting bitumen product contains a reduced amount of water wetted minerals.
For the purpose of the present invention, extra water is defined as water that is added to the mixture to reduce the minerals content of the aqueous phase and to facilitate the transfer of water wetted minerals from the bitumen phase to the aqueous phase in one embodiment of the invention. Normally this extra water is added in the recovery zone of an apertured oleophilic belt separator to help remove bitumen phase 133~584 from the top flight of this belt. It may also be added to the drum of the present invention for the purpose of reducing the mineral content of the aqueous phase of the mixture and thereby encourage the transfer of water wetted minerals from the bitumen phase to the aqueous phase. Extra water normally becomes part of the free water that is not emulsified with the bitumen phase of the mixture.
I have discovered that when a mixture of bitumen, bitumen wetted minerals, water and water wetted minerals are passed to an apertured oleophilic wall in a separation zone, the bitumen and bitumen wetted minerals will cling to this wall when they come in contact with it but the water and the water wetted minerals will pass through the wall apertures. When this wall is stationary, only a relatively small amount of bitumen and bitumen wetted minerals can be collected in this manner since the bitumen and bitumen wetted minerals accumulating on the wall surfaces will close the apertures. However, when the wall is moving, and bitumen and minerals are removed from the wall, more mixture can be separated in this manner without danger of closing the apertures. Furthermore, when the wall is a moving endless belt that has at least one separation zone for separating the mixture in these two phases and at least one recovery zone for removing the clinging bitumen and bitumen wetted minerals from the belt surfaces and out of the belt apertures, the process becomes continuous and large amounts of mixture can be separated per day or per year by the moving belt on a continuous basis.
I have found that optimum separation is achieved by an apertured oleophilic endless belt when the bitumen particles and bitumen wetted particles of the mixture, that flow to the belt, are large enough that most of them contact the surfaces of the endless belt -- as the aqueous phase passes through the belt apertures.
When the bitumen particles are too small, the probability of them being captured by the belt surfaces is low. They tend to pass through the belt apertures with the aqueous phase without contacting the belt surfaces, and remain part of the aqueous mixture leaving the separation zone. Reducing the aperture size of an apertured oleophilic endless belt increases the probability of bitumen coming in contact with these belt surfaces, but in many cases other factors, such as mineral particle size in the mixture, make it undesirable to reduce the aperture size of the belt.
I have further found that small bitumen particles and bitumen wetted mineral particles suspended in an aqueous mixture may be increased in size by tumbling this mixture in a drum with oleophilic surfaces. The oleophilic drum surfaces capture these small bitumen and mineral particles so that they form a layer on those surfaces that progressively increases in thickness until it becomes too thick to sustain itself in the presence of gravity forces in the drum and shear forces in the tumbling mixture. These forces cause a flowing off or a sloughing off of enlarged bitumen particles and enlarged bitumen wetted mineral particles from the oleophilic drum surfaces. The enlarged bitumen and mineral particles, thus returning to the mixture, may continue to tumble in the drum, may capture additional bitumen and minerals, may be captured by other oleophilic drum surfaces and, may flow from these surfaces when they reach the exit of the drum. In addition, the bitumen and bitumen wetted minerals may flow along the mechanical surfaces in the drum interior and flow therefrom when they reach the drum exit. I have found that the resulting mixture that emerges from this drum contains bitumen particles and bitumen wetted mineral particles that are much - large than the bitumen particles and bitumen wetted mineral particles contained in the mixture that enters this drum.
I have further found that when a bitumen product, containing bitumen, bitumen wetted minerals and excess water is tumbled in a drum with oleophilic surfaces, the repeated adhesion and shedding of bitumen and bitumen wetted minerals to and from oleophilic internal drum surfaces in the presence of excess water causes water wetted minerals, present in the bitumen phase, to be exposed to the aqueous phase of the mixture. This exposure in the tumbling mixture causes a transfer of water wetted minerals from the bitumen phase to the aqueous phase. Subsequent separation with an apertured oleophilic endless belt of this tumbled mixture results in a bitumen phase that contains less water wetted minerals than the bitumen phase that entered the drum.
When a mixture entering the drum contains a relatively low water content, and a correspondingly high water wetted minerals content, water may have to be added to the drum to enhance the transfer of water wetted minerals from the bitumen phase to the aqueous phase by the oleophilic drum surfaces. In that case the final bitumen phase may contain a higher percentage of water than the bitumen phase that entered the drum, but it usually contains a much lower percentage of minerals.
A drum of the present invention is illustrated in Figure 1. Mixture to be processed enters the revolving drum from a stationary pipe (13) and a rotary seal (12) and leaves the drum through a rotary seal (14) to a stationary pipe (15). The drum (l) has a front wall (9), a cylindrical side wall (10) and a rear wall (11).
The front and rear walls may be straight, coned or dished. Trunnion rings (2) may be mounted on the drum side wall (10) to support the drum on four revolving rollers (3) and revolve the drum. These rollers (3) - 1~34584 - are mounted on shafts (4) supported in bearings in pillow blocks (5). At least one of these shafts (4) is driven by an electric motor (7) through a gear box (6), or the drum is driven by a motor with sprockets and a chains or by a hydraulic motor. The roller assembly is mounted on a steel base (8) to support the drum (1) in a stable manner. A cut out (16) is shown in Figure 1 to show column packings (18) with oleophilic surfaces that pass through the mixture (17) as the drum tumbles. The mixture (17) level in the drum is preferably maintained at approximately the mid point of the drum cross section, filling the free volume of the drum to 50%. However, it may average as low as 30% or as high as 70% of the free volume of the drum, by tilting the drum (1), by increasing the size of the rotary seals (12 and 14) of the drum, or by separately controlling the inlet and outlet pressure while weighing the drum and its contents. Instead of trunnion rings and rollers, the drum may be supported by bearings.
An inside view of Figure 1 is shown in Figure 2.
The drum is tightly packed with oleophilic column packings (18) that were loaded into the drum through the drum flanges (21) and closure plates (51) of the inlet distributor (25) or the outlet distributor (26) at either end of the drum (1). These column packings are of low density and typically are made from a plastic material such as polypropylene that is oleophilic and that has good abrasion resistance. They are tightly packed into the drum and the drum interior is baffled or roughened on purpose so that when the drum revolves, the tower packings do not slide or tumble but remain stationary with respect to the drum walls. However, the drum packings (18) have large openings through which the mixture (17) can pass as the drum revolves. Mixture enters the drum from a ~ stationary pipe (13), through a rotary seal (12), 133 58 through drum flanges (21) and through the apertured walls of the inlet distributor (25). It passes through the tower packings (18) in the drum (1) inside and then leaves the drum through the apertured wall of the of the outlet distributor (26), through drum flanges (21), through a rotary seal (14) and to a stationary pipe (15).
An alternative inside of a drum of the present invention is shown in Figure 3 where oleophilic ropes, rods, pipes or strands are used instead of oleophilic column packings. Mixture enters this drum from a stationary pipe (13), through a rotary seal (12), through drum flanges (21) and then flows into the drum interior where it passes by a structure that supports long oleophilic members (24), such as oleophilic ropes, strands, rods or pipes. It tumbles past those oleophilic members (24) through the revolving drum (1) and leaves the drum through drum flanges (21), through a rotary seal (14) and to a stationary pipe (15). The oleophilic members (24) are supported by steel flat bar grating or molded flat bar plastic grating (27) that allow for uniform spacing of the oleophilic members over the cross section of the drum (1). This grating is supported by an angle iron ring (28) and channels or I beams (19) that are attached to a steel pipe (20) to form a strong structure to support the oleophilic members throughout the drum (1). Panels of grating (27) may also be mounted at the mid point of the drum inside, or at other locations along the the pipe (20) wall to maintain even and uniform spacing of the oleophilic members (27) throughout the drum cross section. The central pipe (20) is closed at one or both ends to prevent flow of mixture through the pipe.
One of the end supports for the oleophilic members is shown in Figure 4. A cross of I beams (19) is welded to the main support pipe (20) and an angle iron ring (28) is welded to the ends of the the I beams (19). Flat bar steel grating (27) or molded plastic grating is mounted onto and is supported by the I beam cross and angle iron ring. Oleophilic members, such as ropes, strands, bands, rods or pipes pass through the holes in the grating and/or are attached to the grating. Perforated steel may be used instead of grating when pipes or rods are used for the oleophilic members if the strength of these pipes or rods, and their resistance to bending, is sufficient. They only have to be inserted in the perforations of the perforated steel supports at both the front and the rear of the drum to remain in place in the drum.
However, when ropes, strands or bands are used for the oleophilic members, they must be strung tightly between the front and rear grating supports to obtain a uniform spacing of oleophilic members throughout the drum cross section. Compared with perforated steel plate, flat bar steel grating or molded plastic grating has smoother edges that are less likely to cut the oleophilic ropes, strands or bands, and are therefore preferred when ropes or strands instead of pipes or rods are used as the oleophilic members.
A method for attaching ropes, strands or bands to the grating is shown in Figures 5 and 6. These oleophilic members (24) are looped over the grating (27) bars and the loops tied together with steel tie wires t29) that prevent movement of the members and cause secure attachment of these oleophilic members (24) to the grating (27), or they are attached with knots to the grating bars.
A rotary seal for use with the drum of the present invention is shown in Figure 7. The inner stationary pipe (31) is attached to the stationary interconnecting piping with a pipe flange (34), and to the inner race 133458~
(38) of a slewing ring bearing or turn table bearing with a bearing flange (32). The revolving outside pipe (30) of the rotary seal is attached to the drum front or rear walls (9 or 11) with a drum flange (21) and to the outer race (33) of a slewing ring bearing or turn table bearing with a bearing flange (33). Bolts (35 and 36) are used to attach the inner pipe and the other pipe to the bearing races.
Three sets of rubber seals may be used to prevent the flow of mixture out of the drum past the inner pipe (31). They are kept in place by snap rings (46) mounted in the outer pipe and with two lantern rings (44 and 45). The first set of two seals (47) closest to the drum flange (21) are separated from a second set of two seals (48) with a lantern ring that allows grease from a grease nipple (43) to fill the volume between these two sets of seals and help prevent the flow of mixture past the inner pipe. A second lantern ring (45) separates a fifth seal (49) from the second set of seals (48) to provide an area for leakage flow to bleed holes (41) in the outer pipe. This fifth seal (49) and bleed hole (41) largely eliminate leakage into the space between the inner race (38) and the outer race (39) of the bearing. However, a second set of bleed holes (42) are provided in the bearing flange (33) of the outer pipe. The end (50) of the inner pipe (31) is tapered to provide for easy insertion of the inner pipe through the seals without damage to the seals during assembly. A regular or periodic replenishment of grease through the grease nipple (43) lubricates both sets of seals (47 and 48), and minimizes or eliminates flow of mixture past these seals. The rotary seal of Figure 7 typically has an inside diameter 10 to 50 centimeters or more in size.
The bearing used for the rotary seal of Figure 7 typically is a single race four point contact ball 133458~

bearing such as is normally used as the mounting bearing for small cranes. These bearings are supplied with drilled flanges for mounting, and they are designed with suitable internal ball spacings that permit mounting such bearings in the vertical plane.
They accept radial loads, axial loads and moment loads and therefore are well suited to give rigidity to the rotary seal. Normally the inner pipe (31) of the rotary seal is attached to plant process piping with a flexible connection, or with a long length of unsupported pipe, to reduce stresses resulting from small misalignments of the rotary seal mountings.
The oleophilic column packings that may be used in the drum of the present invention may be cylindrical rings, Pall (R) rings, Novalox (R) sadles, Berl sadles or may be Tri-packs (R) fabricated by Jeager Products Inc. and described in Canadian patent 1,150,621, or may be other shapes that are conventionally used as mass transfer column packings. They may be made from metal or from plastic and/or they may be coated with an oleophilic coating. Preferably they are molded from polypropylene or from other strongly oleophilic and abrasion resistant plastics.
Figure 8 is a schematic drawing of an apertured oleophilic belt separator that uses an embodiment of the present invention to increase the particle size of bitumen and mineral particles of an aqueous mixture in direct conjunction with the apertured belt. The drum of Figure 8 is shown in side view, on a somewhat smaller scale, in Figure 9. Construction details of the wall of the drum are shown in Figure 10. The separator consists of a drum (51), with a central shaft (52) supported in pillow block bearings (53). The shaft (52) is hollow and has holes (71) inside the drum to permit mixture to be pumped into the drum via a rotary seal (54). Mixture flows into the drum and 133~84 leaves the drum through apertures (55) in the cylindrical drum wall (56) to fill the tank (57) surrounding the drum (51). As the mixture flows through the drum apertures (55), it encounters an apertured oleophilic belt (58) on the exterior of the cylindrical drum wall (56). Water and water wetted minerals of the mixture (59) flow through the apertures (60) of this belt but bitumen (61) and bitumen wetted minerals adhere to the belt surfaces (73) on contact and are conveyed by that belt (58) to a recovery zone (62) where high pressure steam, or high pressure water from a bank of nozzles (63) blow this bitumen and minerals from the belt into a bitumen product receiver (64). The apertured belt (58) is an endless belt, supported by the drum (51) to form a separation zone, and by two conveyor rollers (102 and 103) to form a recovery zone. As the drum (51) revolves continually, bitumen and minerals are continually conveyed from the drum wall (56) to the recovery zone (62).
The interior of the drum (51) may be filled with oleophilic column packings, similar to the drum of Figure 2. Alternately it is provided with oleophilic rods, pipes or ropes (65), similar to the drum of Figure 3. These oleophilic members (65) may be mounted longitudinally in the drum (51) as in Figure 3, or they are mounted radially in the drum between a support structure (66) that is concentric with the drum inlet (67) and the cylindrical wall (56) of the drum.
The mixture flows from the central inlet (67) of the drum in a radial direction to the apertures (55) in its exterior cylindrical wall (56). The oleophilic pipes, rods, strands or ropes (65) in Figure 8 are mounted in the drum interior in radial alignment from the center of the drum to the cylindrical drum wall (56) in the same general direction as the flow of the mixture. During operation the drum revolves. The ~ oleophilic surfaces (65) revolve through the mixture (59) in the drum and bitumen and bitumen wetted minerals, coming in contact with these oleophilic members (65), adhere to them. They build up on these surfaces until the shear forces and gravity forces in the drum cause a shedding of bitumen and minerals from these surfaces back into the mixture (59) in the form of enlarged bitumen particles. A continuous adhesion and shedding of bitumen and minerals to and from the oleophilic members of the revolving drum takes place in the mixture. As a result, bitumen and bitumen wetted minerals accumulate in the drum (51) and then flow through the apertures (55) of the drum wall (56) to the apertured endless belt (58). They are conveyed to the recovery zone (62) where they collect in the bitumen receiver (64) and are removed therefrom to further processing. The bitumen and bitumen wetted minerals depleted mixture flows into the tank (57) surrounding the drum and belt, and is pumped from this tank to disposal or further processing.
Long oleophilic members in the drums of the present invention, such as pipes, rods, ropes or strands in Figure 8 are shown placed in the drum in general alignment with the flow of mixture through the drum. They may also be place generally perpendicular to the flow of mixture through the drum.
The cylindrical wall (56) of the drum of Figure 8 may be made from perforated steel, or may may be made from flat bar grating rolled in the form of a cylinder.
This is shown in more detail in Figure 10. A large number of angle iron rings (68) are rolled to a suitable diameter and are placed in parallel about half a meter apart to form the inside drum (51) wall supports. Steel flat bar grating (69) is placed over these inside supports (68), bent into a cylinder and welded to the angle iron supports to form a very rigid 133q584 drum wall (56) with a large percentage open area. End walls (70), with man holes (not shown), are welded to this cylindrical wall (56) and a central shaft (52) is provided that mounts in pillow block bearings (53) to provide rotatable support for the drum (51). The shaft (52) is hollow. Holes (71) are made in the shaft (52) inside the drum. A rotary seal (54) is mounted on one or both ends of the shaft (52) to accept mixture under pressure from a stationary pipe. When only one rotary seal is used to supply mixture to the drum, the other end of the shaft is blocked to prevent loss of mixture.
Tank walls (72) are provided around the drum, and holes are provided in these walls to permit passage of the drum shaft ~52). Seals may be mounted in these holes to reduce or prevent the loss of mixture from the tank (57) of the separator whose level (75) preferably is below the level of the shaft (52) of the drum.
Figure 11 is a flow diagram of a typical process that uses several embodiments of the present invention.
It is a flow diagram for recovering bitumen and minerals from tailings pand sludge. It uses three apertured endless belt separators. It also uses two drums of the present invention. One drum is used to increase the particle size of bitumen and bitumen wetted heavy minerals, and the other drum is used to remove water and water wetted clay from the bitumen product of the two first separators. Sludge (76) is pumped from a tailings pond into the first separator (77) to recover the bulk of the bitumen and bitumen wetted minerals from that sludge (76) The bitumen and minerals depleted sludge (78) is then pumped to a revolving drum (79) filled with oleophilic column packings. This drum serves to increase the particle size of bitumen and bitumen wetted minerals that have passed through the apertures of the belt of the first separator (77). After leaving the first drum (79), the 133~58~
~~ mixture is pumped to a second separator (80). There the apertured belt captures the bitumen and minerals that were increased in size by this drum (79) of the present invention. After that, the tailings mixture (82) of the second separator (80) is discarded. The bitumen and minerals product(83, 84) from both separators is combined. It is pumped to a second drum (85) where clay is removed from the bitumen product and transferred to the water phase. Jets of water from nozzles (86, 87) are used in the first two separators.
This causes extra water to be mixed with the bitumen and minerals product (83, 84) of these two separators.
The resulting bitumen product and its extra water (88) is tumbled in the second drum (85). Using an embodiment of the present invention, this drum exposes clay and silt particles from the bitumen phase and transfers these to the aqueous phase of the mixture.
The tumbled mixture (89) from the second drum (85) then flows into the third separator (90) where the bitumen phase is separated from the aqueous phase. Indirect heat (91) is used in the recovery zone (95) of this third separator (90), in stead of jets of water or steam, to remove bitumen from the top flight (92) of the endless belt. As a result, the bitumen product (93) from this separator (90) contains much less water than the product of the previous two separators. This bitumen product (93) is removed from the third separator (90) and pumped to further processing. The aqueous phase tailings (94) from the third separator (90) are either pumped to the top of a tailings pond (not shown) for settling of the contained clay and silt, or it is blended with the sludge feed to the first or second separator.
In the present invention therefore, bitumen particles and bitumen wetted mineral particles in an aqueous mixture are increased in size by tumbling the mixture in a drum in the presence of oleophilic surfaces that do not tumble but that revolve in unison with the drum interior walls and surfaces. The bitumen particles and bitumen wetted mineral particles adhere to the oleophilic surfaces upon contact and accumulate on these surfaces to form a layer that increases in thickness until a portion of it sloughs off back into the mixture, or until it flows out of the drum along the mechanical oleophilic surfaces. When sloughed off back into the mixture, it mixes with the bitumen particles and with the bitumen wetted mineral particles and is recaptured by oleophilic surfaces. It may continue to be sloughed off these surfaces until it reaches the drum exit and flows out with the mixture.
As a result of passing through the drum of the invention, the mixture that leaves said drum contains bitumen particles and bitumen wetted mineral particles that are larger than the bitumen particles and bitumen wetted mineral particles that enter the drum. The process is a continuous process with mixture continuously entering the drum of the invention and mixture continuously leaving the drum. Generally the drum is filled with mixture to its mid point but it may also contain less mixture or more mixture. Compressed air may be added to the feed of the drum, when the level of mixture in the drum is higher than desired, to decrease the level of said mixture. The mixture coming from the drum is suitable for subsequent separation with an apertured oleophilic moving endless belt or with an apertured oleophilic moving wall.
Normally the mixture enters the drum of the present invention through one end wall. It passes through the drum interior in a longitudinal direction and leaves the drum through the other end wall. However, the drum of the present invention may also form part of an apertured oleophilic endless belt separator. In that - 133458~
case the mixture enters through one end wall but it leaves through apertures in the cylindrical drum wall, which is covered by an apertured oleophilic endless belt.
The drum of the present invention may also be used to improve the quality of bitumen products, such as bitumen froth from a hot water process, bitumen froth from other flotation processes, or bitumen product from an apertured oleophilic endless moving belt. The bitumen product entering the drum may contain air, bitumen, bitumen wetted minerals, water and water wetted minerals. This mixture, as it tumbles with oleophilic surfaces in the drum becomes deaerated and the bitumen comes in contact with the mechanical oleophilic surfaces of the drum. Bitumen and bitumen wetted minerals, continuously collect on these oleophilic surfaces and shed from these surfaces. When extra water is present in the mixture, this adhesion and shedding of bitumen particles causes exposure of water wetted minerals from the bitumen phase to water, and a transfer of them to the aqueous phase of the mixture. These water wetted minerals thus become part of the aqueous phase of the mixture and are recovered with the aqueous phase when the mixture that issues from the drum is subsequently separated with an apertured oleophilic endless moving belt. The resulting bitumen phase product contains a lower percentage of minerals than the bitumen phase of the feed to the drum and hence, this embodiment of the invention has improved the quality of the bitumen product.

EXAMPLE

Sludge from the tailings pond of a mined oil sands plant at 5 degrees C. , containing 5% bitumen, 70%

water and 25% solids composed mainly of clay, is provided from a pump, submerged 15 meters below the surface of that pond, to a separator using an apertured oleophilic moving endless belt. Two hundred cubic meters of sludge per hour are separated by this belt, resulting in 20 cubic meters per hour of bitumen product, consisting of 10% mineral, 30% bitumen and 60%
water. The sludge that has passed through the apertures of the endless belt of the separator is pumped to a 2 meter inside diameter, 6 meter long drum containing a structure supporting six hundred 1 centimeter diameter woven polypropylene ropes, tightly strung longitudinally between structural supports inside the drum and uniformly spaced over the drum cross section. The drum is supported on two trunnion rings that are 20 centimeter wide and 2.2 meters in outside diameter resting on four rollers that are supported on two shafts in bearings in pillow blocks on a steel frame. One of the two shafts is driven by an electric motor through a gear box, resulting in drum rotation of 3 RPM. Sludge enters and leaves this drum through rotary seals as shown in Figure 7. Sludge leaving the drum is pumped to a second apertured oleophilic movin~ endless belt separator, resulting in approximately 11 cubic meters per hour of bitumen product consisting of 20 % minerals, 30% bitumen and 50% water. The aqueous phase from this second separator is considered spent sludge and is sent to disposal to a new holding pond in a mined out portion of the mined oil sands site. The bitumen product from both separators is combined and 10 cubic meter of water per hour and is added to this combined product stream and is pumped to a 2 meter inside diameter, 6 meter long drum containing a structure supporting six hundred 1 centimeter diameter woven polypropylene ropes, tightly strung longitudinally in the drum inside and -133458~
uniformly spaced over the drum cross section. The drum is supported on two trunnion rings that are 20 centimeter wide and 2.2 meters in outside diameter resting on four rollers that are supported on two shafts in bearings in pillow blocks on a steel frame.
One of the two shafts is driven by an electric motor through a gear box, resulting in drum rotation of 1 RPM. A third apertured oleophilic moving endless belt separator is used to separate the product mixture coming from this second drum. Approximately 15 cubic meters of bitumen product per hour are produced by the third separator consisting of 10% mineral, 60% bitumen and 30% water while approximately 15 cubic meters of aqueous phase are returned to the top of the original tailings pond to allow settling of the contained water wetted solids. The bitumen product from the third separator is blended with an equal amount of naphtha, is heated to 150 degrees C. and is pumped to centrifuges to remove water and minerals. The overflow of the centrifuges is pumped to a naphtha recovery unit from where the recovered naphtha is returned for reuse as a bitumen blend for the centrifuges. The bitumen product from the naphtha recovery unit is pumped to coking and upgrading to produce synthetic crude oil.
The underflow from the centrifuges contains mainly water and minerals with some residual bitumen and naphtha. This underflow is pumped to a fluidized bed reactor to flash off the water and naphtha and to burn off the bitumen and carbon mineral. The hot minerals from the fluidized reactor are quenched and are separated by mineralogical methods into heavy minerals and light minerals and the light minerals are discarded. The heavy minerals are further processed to recover titanium and zirconium ore.

~ Although the invention as has been described is deemed to be that which forms the preferred embodiments thereof, it is recognized that departures may be made therefrom and still be within the scope of the invention which is not to be limited to the details disclosed but is to be accorded the full scope of the claims so as to include any and all equivalent methods and apparatus.
For example, in the aspect of the invention for removing water wetted minerals from the bitumen phase of a feed mixture, extra water may be part of the mixture, it may be added to the mixture before it enters the drum, or it may be added to the mixture in the drum. A high water content, a low minerals content in the water phase and a high water wetted or water wetable minerals content in the bitumen phase of the mixture will result in the transfer of minerals from the bitumen phase to the water phase of that mixture during the process of the invention. This is because low minerals content in the water phase in the drum of the present invention encourages water wetted minerals to leave the bitumen phase and become part of the water phase. Tumbling such a mixture in the drum of the present invention encourages water wetable minerals in the bitumen phase to become water wetted.

Claims

1. A method for increasing the mean particle size of bitumen and bitumen wetted mineral particles in a feed mixture of bitumen, water, bitumen wetted minerals, and water wetted minerals, which comprises the steps of:
a) introducing said feed mixture into a rotating drum that contains an abundance of oleophilic mechanical surfaces, said drum rotating at a rate not exceeding the critical rotation rate and said oleophilic surfaces rotating in fixed relationship with the walls of said drum, b) tumbling said mixture in the rotating drum so that said oleophilic surfaces continually pass through said mixture and come in contact with said bitumen particles and with said bitumen wetted mineral particles causing said particles to unite to form bitumen phase particles that are larger in size than the particles of bitumen in the feed mixture initially introduced into said drum, and c) removing tumbled mixture containing said enlarged bitumen phase particles from said drum.

2. A method as in Claim 1 which includes the further step of separating the enlarged bitumen particles from the aqueous phase by means of an apertured oleophilic endless moving belt or an apertured oleophilic moving wall.

3. A method as in Claim 1 wherein the drum rotates about a generally horizontal axis.

4 A method for removing water wetted minerals from the bitumen phase of a feed mixture consisting of bitumen, bitumen wetted minerals,water wetted minerals, and water which comprises the steps of:
a) introducing said feed mixture into a rotating drum that contains an abundance of oleophilic surfaces, said drum rotating at a rate not exceeding the critical rotation rate and said oleophilic surfaces rotating in fixed relationship with the walls of said drum, b) tumbling said feed mixture in the rotating drum with said oleophilic surfaces causing water wetted minerals in the bitumen phase of the mixture to be exposed and causing these minerals to become part of the aqueous phase of said mixture, c) separating said tumbled mixture with an apertured oleophilic endless moving belt or with an apertured oleophilic moving wall into a bitumen phase product and an aqueous phase effluent.

5. A method as in Claim 1 or 4 wherein said oleophilic mechanical surfaces are the surfaces of column packings suitable for mass transfer in columns.

6. A method as in Claim 5 wherein said column packings are plastic or metal Novalox saddles, Berl saddles, Pall rings or Tri-packs column packings.

7. A method as in Claim 1 or 4 wherein said oleophilic mechanical surfaces are pipes, rods, ropes or strands mounted inside said drum , separated from each other and aligned generally parallel with the flow of mixture through said drum.

8. A method as in Claim 1 or 4 wherein said oleophilic mechanical surfaces are pipes, rods, ropes or strands mounted inside said drum separated from each other and aligned generally perpendicular to the flow of mixture through said drum.

9. A method as in Claim 1 or 4 wherein said feed mixture enters into said drum through one end wall, flows longitudinally through said revolving drum and said tumbled mixture leaves said drum through the other end wall.

10. A method as in Claim 4 or 6 wherein the drum rotates about a generally horizontal axis.

11. A method as claimed in Claim 10 wherein said oleophilic mechanical surfaces are the surfaces of column packings suitable for mass transfer in columns.

12. A method as in Claim 1 or 4 wherein said feed mixture enters into said drum from a central hollow shaft through one or both end walls of the drum, flows radially from said central hollow shaft to the cylindrical wall of the drum, which is apertured and which is covered on the outside at least partly with an apertured oleophilic endless belt.

13. A method as in Claim 12 wherein water and water wetted minerals of said tumbled mixture leave through apertures of the cylindrical wall of said drum, pass through apertures of said apertured endless belt and flow into a tank surrounding said drum, and are removed therefrom, while bitumen and bitumen wetted miner-als of the tumbled mixture adhere to surfaces of said endless belt and are conveyed to a recovery zone where bitumen and bitumen wetted minerals are removed from the surfaces of said belt.

14. A method as in Claim 13 wherein a bank or banks of nozzles are used to remove bitumen and bitumen wetted minerals from said belt surfaces in the recovery zone.

15. A method as in Claim 9 wherein feed mixture enters said hollow shaft through a rotary seal.

16. A method as in Claim 13 wherein feed mixture enters said hollow shaft through a rotary seal.

38a

17. A method as in Claim 1, 2 or 3 wherein said feed mixture is a mined oil sands tailings pond sludge.

18. A method as in Claim 1, 2 or 3 wherein said feed mixture is a digested mixture of mined oil sands and water.

19. A method as in Claim 1, 2 or 3 wherein said feed mixture is a mined oil sand extraction tailings stream.

20, A method as in Claim 1 or 4 wherein said feed mixture is from an oil well that has been stimulated with heat to produce a mixture of bitumen, water and minerals .

21. A method as in Claim 1, 2 or 3 wherein said feed mixture has once or more times before passed through the apertures of an apertured oleophilic moving endless belt or of an apertured oleophilic moving wall before it enters said drum.

22. A method as in Claim 4 wherein said feed mixture is or contains a bitumen product from a mined oil sands plant.

23. A method as in Claim 4 wherein said feed mixture is or contains a bitumen or heavy oil product from an in situ oil or bitumen recovery plant.

24. A method as in Claim 4 wherein said feed mixture is or contains a bitumen froth from a mined oil sands hot water process.

25. A method as in Claim 4 wherein said feed mixture is or contains a bitumen froth from a mined oil sands bitumen froth flotation process.

26. A method as in Claim 4 wherein said feed mixture is or contains a bitumen froth from a minerals recovery froth flotation process.

27. A method as in Claim 4 wherein said feed mixture is or contains a bitumen product from an apertured oleophilic moving endless belt separator or from an apertured oleophilic moving wall separator.

28. A method as in Claim 1 or 4 wherein the temperature in said drum is between zero and 50 degrees C.

29. A method as in Claim 28 wherein the temperature in said drum is between 10 and 30 degrees C.

30. A method as in Claim 1 or 4 wherein the viscosity of the bitumen phase in said drum is between 10,000 and 5,000,000 centipoises.

31. A method as in Claim 30 wherein the viscosity of the bitumen phase in said drum is between 50,000 and 1,500,000 centipoises.

32. A method as in Claim 1 or 4 wherein the rate of drum rotation does not exceed 30% of the critical rotation rate.

33. A method as in Claim 32 wherein the rate of drum rotation does not exceed 10% of the critical rotation rate.

34. An apparatus for increasing the mean particle size of bitumen and bitumen wetted mineral particles in a feed mixture of bitumen, water, bitumen wetted minerals and water wetted minerals, or for removing water wetted minerals from the bitumen phase of such a feed mixture, which apparatus comprises:
a) a generally horizontal rotatable drum containing an abundance of mechanical oleophilic surfaces that are in fixed relationship with the inside walls of said drum, b) a means for entry of feed mixture into said drum and a means for exit of tumbled mixture from said drum.
c) a means for rotating said drum and a means for supporting said rotatable drum

35. An apparatus as in Claim 34 wherein the entrance for said feed mixture is through one end wall of said drum and the exit for tumbled mixture is through the opposite end wall of said drum.

36. An apparatus as in Claim 34 wherein the entrance for said feed mixture is through one or both end walls of said drum and the exit for tumbled mixture is through apertures in the cylindrical wall of said drum.

37. An apparatus as in Claim 36 wherein an apertured oleophilic endless belt covers at least part of the cylindrical wall of said drum, said endless belt being supported by conveyor rollers that permit continuous conveying of bitumen phase from the drum wall to a bitumen recovery zone, and a tank enclosing at least the bottom half of said drum.