CA1241297A - Oleophillic adhesion type separation of minerals using a moving apertured collection barrier - Google Patents
Oleophillic adhesion type separation of minerals using a moving apertured collection barrierInfo
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- CA1241297A CA1241297A CA000407183A CA407183A CA1241297A CA 1241297 A CA1241297 A CA 1241297A CA 000407183 A CA000407183 A CA 000407183A CA 407183 A CA407183 A CA 407183A CA 1241297 A CA1241297 A CA 1241297A
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Abstract
ABSTRACT
Process for recovering minerals from mixtures containing the mineral particles and other particulate solid particles termed gangue, which process involves the attraction of the minerals to an oil phase containing an oleophilic collector leaving the gangue in the aqueous phase and removing the oil phase by passage through a special apertured oleophilic surface. The pro-cess comprises: (1) insuring that the mineral particles in the mixture have an oleophilic surface and such surface is sufficiently large to be attracted to other oleophilic surfaces, (2) passing the mixture containing the mineral particles and the other particulate solid particles through an apertured surface which is oleophilic so that the mineral particles are attracted to the said oleo-philic apertured surface and the other particulate solid particles pass through the apertures, and (3) removing the mineral particles from the aper-tured surface.
Process for recovering minerals from mixtures containing the mineral particles and other particulate solid particles termed gangue, which process involves the attraction of the minerals to an oil phase containing an oleophilic collector leaving the gangue in the aqueous phase and removing the oil phase by passage through a special apertured oleophilic surface. The pro-cess comprises: (1) insuring that the mineral particles in the mixture have an oleophilic surface and such surface is sufficiently large to be attracted to other oleophilic surfaces, (2) passing the mixture containing the mineral particles and the other particulate solid particles through an apertured surface which is oleophilic so that the mineral particles are attracted to the said oleo-philic apertured surface and the other particulate solid particles pass through the apertures, and (3) removing the mineral particles from the aper-tured surface.
Description
PROCESS FOR RECOVERING MINERALS
FROM MIXTURES CONTAINING THE SAME
BACKGROUND OF THE INVENTION
Industrial nations are constantly increasing their metal consumption and the known supply of metal, and particularly copper, lead and zinc is shrinking and in a few years the metal industry may not be able to supply the world needs. There are, however, still large quantities of minerals in very low grade ore that have been hereto untouched because of the difficulty in recovering the valuable minerals from the other solid material which is of little value.
In the low grade ore, the desired minerals many times appear only as just a few specks mixed with other minerals or solids, and a great amount of material must be handled to recover the small amount Owe desired mineral.
Any process for recovery of the desired minerals from low grade ore should involve as few handling steps as possible.
In addition, there has been difficulty 1 in developing processes that can detect or select the small amount of mineral from the large amount of solids of little value generally termed guying.
This operation known as ore dressing generally involves comminution or fragmentation of the ore to small size to permit easy separation of the different kinds of solids, followed by one or more sorting operations designed to distinguish and separate the valuable mineral particles from the rest. In the past the sorting has generally been accomplished by techniques, such as, for example, those based on gravity, magnetism or chemical attraction or reaction.
The gravity separation processes depend upon the different rates of fall through water and are patterned after the simple panning technique where the particles are swirled with water in a shallow conical dish with the effect that the dense particles stratify in the bottom while the lighter minerals being more buoyant remain partly in suspend soon and can be decanted with water from time to time. The modern successors to the panning technique use more complicated steps and equipment, but the -3 "$~
1 process is still limited by difficulties of ox-twining particles of the right size, interference with walls and bottoms of the containing vessels, and the like.
The magnetic separation process can be used for separating only a few minerals. The most obvious case is that of the ferromagnetic magnetize and minerals that can be chemically altered to produce magnetites Such separators work efficiently only if the material is presented in rather a thin layer only a few particles deep.
Consequently the design of a high capacity plan for use with fine material at reasonable cost is scarcely practicable.
Froth flotation is probably the more desirable of the sorting processes as it operates through the sensitive surface properties of the individual minerals. It is generally applicable to very fine concentrates and can distinguish not only ore mineral from guying but one ore mineral from another. Briefly, conditions are arranged so that when a mixture is agitated and air bubbles are blown through it certain minerals attach them-I
1 selves to the bubbles and are floated out in a froth which is skimmed off and discharged of its mineral burden. In many cases the surface properties of the ore and guying minerals vary within too narrow a range to be useful for effective separation, and as a result certain organic compounds called collectors are added to bring about more selective adsorption. The main type of collectors are organic acids, their ;- salts, organic bases and oils, swishes kerosene, I-- creosotes, diesel or fuel oils. To be effective, these processes generally require strict control "
Jo of pi and addition of many additives, such as conditioners, wetting agents, frothing agents, .., ...., 5~ C -i which add greatly to the cost, particularly when treating large quantities of ore. In addition, the technique requires that the minerals be ground to very fine particles before an effective swooper-lion can be accomplished.
It is an object of the present invention, therefore, to provide a new and improved process for extracting minerals from mixtures containing them. It is a further object to provide a process I I
1 for sorting or extracting valuable minerals from guying which can be effectively operated on large quantities of ore, can be operated with few operational steps, is operative with particles of great variety of size, is dependent upon very few process variables and can be made effective for the separation of a great variety of different mineral ores.
SUMMARY OF THE INVENTION
It has now been discovered that these and other objects can be accomplished by the pro-cuss of the invention which provides a new, improved and highly efficient technique for recovering valuable minerals from mixtures containing the said minerals and particles of little value termed guying, and particularly low grade ore containing the minerals. The process comprises (1) insuring that the mineral particles in the mixture have an oleophilic surface and such surface is sufficiently large to be attracted to other oleophilic surfaces,
FROM MIXTURES CONTAINING THE SAME
BACKGROUND OF THE INVENTION
Industrial nations are constantly increasing their metal consumption and the known supply of metal, and particularly copper, lead and zinc is shrinking and in a few years the metal industry may not be able to supply the world needs. There are, however, still large quantities of minerals in very low grade ore that have been hereto untouched because of the difficulty in recovering the valuable minerals from the other solid material which is of little value.
In the low grade ore, the desired minerals many times appear only as just a few specks mixed with other minerals or solids, and a great amount of material must be handled to recover the small amount Owe desired mineral.
Any process for recovery of the desired minerals from low grade ore should involve as few handling steps as possible.
In addition, there has been difficulty 1 in developing processes that can detect or select the small amount of mineral from the large amount of solids of little value generally termed guying.
This operation known as ore dressing generally involves comminution or fragmentation of the ore to small size to permit easy separation of the different kinds of solids, followed by one or more sorting operations designed to distinguish and separate the valuable mineral particles from the rest. In the past the sorting has generally been accomplished by techniques, such as, for example, those based on gravity, magnetism or chemical attraction or reaction.
The gravity separation processes depend upon the different rates of fall through water and are patterned after the simple panning technique where the particles are swirled with water in a shallow conical dish with the effect that the dense particles stratify in the bottom while the lighter minerals being more buoyant remain partly in suspend soon and can be decanted with water from time to time. The modern successors to the panning technique use more complicated steps and equipment, but the -3 "$~
1 process is still limited by difficulties of ox-twining particles of the right size, interference with walls and bottoms of the containing vessels, and the like.
The magnetic separation process can be used for separating only a few minerals. The most obvious case is that of the ferromagnetic magnetize and minerals that can be chemically altered to produce magnetites Such separators work efficiently only if the material is presented in rather a thin layer only a few particles deep.
Consequently the design of a high capacity plan for use with fine material at reasonable cost is scarcely practicable.
Froth flotation is probably the more desirable of the sorting processes as it operates through the sensitive surface properties of the individual minerals. It is generally applicable to very fine concentrates and can distinguish not only ore mineral from guying but one ore mineral from another. Briefly, conditions are arranged so that when a mixture is agitated and air bubbles are blown through it certain minerals attach them-I
1 selves to the bubbles and are floated out in a froth which is skimmed off and discharged of its mineral burden. In many cases the surface properties of the ore and guying minerals vary within too narrow a range to be useful for effective separation, and as a result certain organic compounds called collectors are added to bring about more selective adsorption. The main type of collectors are organic acids, their ;- salts, organic bases and oils, swishes kerosene, I-- creosotes, diesel or fuel oils. To be effective, these processes generally require strict control "
Jo of pi and addition of many additives, such as conditioners, wetting agents, frothing agents, .., ...., 5~ C -i which add greatly to the cost, particularly when treating large quantities of ore. In addition, the technique requires that the minerals be ground to very fine particles before an effective swooper-lion can be accomplished.
It is an object of the present invention, therefore, to provide a new and improved process for extracting minerals from mixtures containing them. It is a further object to provide a process I I
1 for sorting or extracting valuable minerals from guying which can be effectively operated on large quantities of ore, can be operated with few operational steps, is operative with particles of great variety of size, is dependent upon very few process variables and can be made effective for the separation of a great variety of different mineral ores.
SUMMARY OF THE INVENTION
It has now been discovered that these and other objects can be accomplished by the pro-cuss of the invention which provides a new, improved and highly efficient technique for recovering valuable minerals from mixtures containing the said minerals and particles of little value termed guying, and particularly low grade ore containing the minerals. The process comprises (1) insuring that the mineral particles in the mixture have an oleophilic surface and such surface is sufficiently large to be attracted to other oleophilic surfaces,
(2) passing the resulting mixture through an aperture wall having an oleophilic surface so that the mineral particles are attracted to the said 1 oleophilic surface and the remaining portion of the mixture containing the guying passes -through the apertures, and (3) removing the mineral particles from the aperture surface. It has been surprisingly found that by the use of this unique process one can effect a separation of small quantities of very fine particles of mineral from large quantities of ore, and can effect such a separation with a small number of operational steps. In addition, the separation can be effected without the use of large quantities of expensive additives and without strict control of reaction conditions, such as phi and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred apparatus to be used in the process of the invention is that shown in US.
4,236,995 and U. S. 4,224,138. Figure 1 is a per-spective view showing an apparatus patterned after that shown in US. 4,224,138 for conducting the process of the invention wherein the aqueous slurry containing the water, stream, crushed ore and oleophilic material is passed through an aver-lure surface which is in the form of a rotating 1 belt contained within a water bath.
Figure 2 and PA are views of a section of an aperture oleophilic sieve belt in the form of a meshed construction.
Figure 3 is a schematic illustration of one method for recovering the mineral-oleophilic material combination from the aperture belt or disc using two rollers.
DETAILED DESCRIPTION OF THE INVENTION
The first step in the process of the invention involves insuring that the mineral particles in the mixture have an oleophilic sun-face of sufficient area to effect attraction of the particles to an oleophilic aperture surface.
As used herein "oleophilic" refers to those surfaces or materials which are attracted to and wettable with oil, as distinguished from oleophobic wherein the surfaces are not so attracted or wetted with oil.
It has been found that precious mineral particles tend to be naturally oleophilic and have oleophilic surfaces unless they are coated with slime or with oxides of iron or other metallic 1 oxides, or with films of hydrophilic matter.
Metals -that are not easily oxidized such as tin also tend to have oleophilic surfaces. Broadly speaking sulfide minerals are or can be made to be oleophilic but oxides, carbonates, silicates and surfaces are mostly oleophilic. Graphite is oleophilic, diamonds are hardly oleophilic and copper is hardly oleophilic. Silver in its native state is oleophilic.
Gold particles, particularly when flaky or in piety form have oleophilie surfaces.
In some cases, the gold particles may be coated with iron oxides or clay and such coatings should be removed by abrasion to expose the oleophilie surface. Silver is also found in small flaky form wherein the surfaces are oleophilic unless coated with material such as iron oxide and clay which can be removed as by abrasion to make the surfaces oleophilie.
Those ours are not naturally Leo-Philip can be made oleophilic by contacting them with what is termed an activator. These materials normally act by absorbing on the surface/solution 1 interface, thereby providing sites for the adsorb-lion of the collector species. For example, addition of oxygen to a gold bearing water sup-pension will increase the oleophilic attraction of gold.
Minerals can also be made oleophilic by the addition of agents known as collectors.
These materials provide the surface of the mineral that is to be recovered with an oily film that makes the mineral oleophilic. Preferred collectors are those which add to the mineral surface to the exclusion of the guying and which have a hydrocarbon chain or a hydrocarbon ring in one part of the molecule or at one end of the molecule and at the other end have a polar element that is likely to combine with the mineral surface.
For example, oleic acid is a preferred collector.
It has a fairly long hydrocarbon chain and at one end of the molecule there is the carboxyl radical which reacts with the mineral surfaces. The same is true of xanthates.
Other examples of the collectors include heavy oils, bitumen, fuel oils, long chain fatty 1 acids, long chain amine, polymeric materials of low molecular weight derived from olefinic and diolefinic compounds, and the like, and mixtures thereof.
The oleophilic collector material added can be ionizing compounds which dissociate into ions in aqueous mixtures and act by attaching to the surface of the desired mineral particles and thereby impart the desired oleophilic pro-parties. The oleophilic collector may also be long chain chelates type materials which enter into a weak chemical bond with the mineral particles. The added oleophilic collector can also be non-ionizing compounds or compositions which are practically insoluble and effect the desired results by forming a thin film on the surface of the mineral particles and thus impart the desired oleophilic character to the resulting combination.
Preferred ionizing collectors to be used are those which are asymmetric in structure and have a non-polar hydrocarbon group attached to the molecule. The ionizing collectors may be ho I
1 anionic or cat ionic or mixtures thereof. examples of these include, among others, organic acids such as oleic acid, linoleic acid, sodium owlet, sodium linoleate, long chain sulfates and sulfonates, xanthates and dithiophosphates, long chain amine, long chain halides, and the like.
The exact ionic collector to be used in the process will depend chiefly upon the electron static attraction between the polar head of the collector and the charged electrical layer on the mineral surface, and a few routine tests will review the most efficient combination of mineral and collector to be utilized.
The non-ionic collectors which generally function by coating the surface o-f the mineral particles may be of any suitable type as long as the necessary attraction to the mineral particle is provided. Examples of suitable materials include, among others, bitumen, heavy oil, diesel oil, crude oil, kerosene, and the like and mixtures thereof.
The first step in the process then is to be sure that the mineral particles have an 1 oleophilic surface. This can be accomplished by selecting mineral particles which by nature have oleophilic surfaces or can be made so by the addition of an activator or by the addition of an activator and a collector or by the addition of a collector only. The exact prove-dune to be used will depend upon the mineral being separated.
The mineral surface should also be large enough that the oleophilic surface will be attracted to the oleophilic aperture surface.
If the area is not large enough it can be increased by grinding or crushing to expose more of the mineral surface. The crushed ore should preferably have a particle size Owe 20 mesh or less and more preferably from 20 mesh to 250 mesh.
The crushing can be accomplished by any conventional technique, such as jaw crushers, gyrator crushers or rolls, and if smaller particles are desired they may be obtained by use of ball mills or similar equipment.
The mixture containing the mineral particles having the oleophillc surface is then I I
1 treated to separate the mineral particles from the guying. This may be accomplished in a variety of ways. A preferred technique comprises passing a mixture of mineral particles having the oleophilic surface and the guying, and preferably a liquid carrier such as water, through an oleophilic aperture wall or barrier or belt which is coated with an oleophilic material, such as oil, bitumen or grease, which captures the oleophilic mineral particles while permitting the hydrophilic guying particles to pass through the apertures. The oil oleophilic material is then removed from the aperture wall and is refined to recover the mineral and the aperture wall is again covered with fresh oleophilic material, such as oil, bitumen or grease to capture more mineral particles in the subsequent sieving.
Another preferred embodiment comprises mixing the mixture or mineral particles having the oleophilic surfaces and the guying with an aqueous medium containing an oleophilic material so that the mineral particles become coated with a thick coating of the said oleophilic material -14~ C~3~^~
1 and the hydrophilic guying becomes coated with water. This is preferably accomplished by tumbling the mineral particles, guying, water and oleophilic material in a drum for a sufficient period to insure that the mineral particles are coated with a thick coating of the oleophilic material. The slurry that is thus prepared is then passed through the aperture oleophilic wall wherein the mineral particles coated with the oleophilic material are attracted to the oleophilic surface of the aver-lured wall, and the hydrophilic guying passes through the apertures. The captured oleophilic material containing the mineral particles is then removed from the aperture surface and the process repeated. There is no need to apply a thick coating of oleophilic material to the oleophilic aperture surface in this case and the thick coating is already on the mineral particles.
Another preferred embodiment comprises adding an emulsion of oleophilic material, such as oil or bitumen, and water to the mixture of mineral particles and guying, and after thorough mixing, adding an emulsion breaker to the mixture.
-15~ I
1 The emulsion used in this case possesses the Leo-Philip material as the dispersed phase and the water as -the continuous phase. When the emulsion breaker is added to the mixture, oil phase particles are free to find the oleophilic surfaces of the mineral particles and adhere thereto. Such particles are then coated with a thick coating of the oleophilic material. The resulting slurry is then passed through the aperture oleophilic wall wherein the mineral particles coated with the Leo-Philip material are attracted to the oleophilic surface of the aperture wall, and the hydrophilic guying passes through the apertures of the said wall. The captured oleophilic material containing the mineral particles is then removed from the aperture surface and the process is repeated.
Another preferred embodiment involves a technique for use when the mineral ore itself contains an oleophilic material. For example, in many cases tar sands and shale oil particles contain mineral particles as well as the oleophilic bitumen or heavy oil. In these cases, the mineral ore particles which contain the desired mineral 1 particles having oleophilic surfaces, the guying and the oleophilic material such as bitumen, heavy oil and the like, are tumbled in a drum in the presence of water and preferably steam, and the mineral particles are coated with a thick coating of the oleophilic material such as bitumen or heavy oil. When this aqueous slurry is passed through the aperture oleophilic wall, the mineral particles coated with the oleophilic material are captured by the wall and the guying passes through the apertures. The mineral particles and Leo-Philip material can then be removed from the wall and the mineral particles recovered.
The aperture wall having the oleophilic surfaces to be used in the above-process of the invention may be of any suitable construction and arrangement as long as it provides openings for the gangueparticles to pass through and an Leo-Philip surface to attract the mineral particles.
Suitable apparatus for -this purpose comprise those shown in US. 4,236,995 and US. 4,224,138. The apparatus preferably has the aperture wall in the form of a screen the cables of which are -17~ 7 1 coated with or made up of an oleophilic material.
The screen may be immersed, not immersed or partly immersed in a water bath.
The preferred apparatus to be used as shown in US. 4,224,138 is illustrated in attached Figure 1.
The apparatus shown in Figure 1 consists of an endless aperture conveyor belt having a top flight 65 and a bottom flight 64 stretched between two conveyor end rolls 51, 52 in a water bath 63 having a water level 42. These end rolls may be crowned to keep the belt running centrally on the end rolls. Both sides of this belt and the wall of the apertures are oleophilic. Slurry from the tumbler is conveyed through conduit 41 into hoppers 43, 44, 45 and 46, the bottom portions of which can be, but do not have to be submerged below the surface of water 42 for the purpose of evenly distributing it at a multiplicity of toga-lions along the belt. Collector recovery stations are mounted along the belt on both flights at a multiplicity of locations 47, 48, 49, 50, 53, 54, 55 and 56.
f~J of 7 1 The separation and collector recovery at the various locations along the belt is similar.
or this reason it is described here for hopper 44 and recovery stations 49 and 54 which together form one separation location. The slurry 59 leaves hopper 44 in the form of a ribbon that is almost as wide as the belt and with a thickness and velocity representing a slurry flow rate that can be conveniently separated by the belt. It falls through the water 42 and is diluted by it until it encounters -the top belt flight 65 where water and the solids in the water phase pass through the apertures of the belt while the collector is attracted to the oleophilic surface of the belt.
The top flight 65 of the belt which is in motion from the right to left carries this slurry along for some small distance before the separation is complete. Baffles 57 or other stirring means are provided to create turbulence in the water above the belt and to disturb any unseparated slurry resting on the belt surface.
The collector-mineral composition is recovered from the belt at location 49. The slurry 2~3~
1 58 that has passed through the apertures of the top flight settle downward to the bottom belt flight. Baffles 60, 61, 70 and 71 serve to contain this slurry so that it will drop onto the bottom conveyor flight. As the slurry passes through the bottom flight 64 water and particulate solids 62 drop to the bottom of the water bath 63 from where they are removed. Substantially all of the collector-mineral composition that was not recovered at the top flight is attracted to the oleophilic surface of the bottom flight 64, which is in motion from left to right. It is recovered at location 54. The solids 62 and the water are removed from the bottom of the water bath 63 at a rate such that a constant water level 42 is maintained in the bath. A pump, auger, or some other mechanical device is used for this purpose.
The aperture oleophilic belt is an important part of the above-described apparatus.
Construction details of this belt are shown in Figure 2 and PA. The belt could consist of rota-lively more rigid members 80 across the belt that are woven into a mesh belt by the use of -20- .29'~
1 relatively more flexible members 81 along the belt. The flexible members 81 consist of cable constituting two or more strands which enclose each member 80 across the belt and which are twisted to maintain the desired spaced relation-ship between the members 80. This belt can be made from oleophilic materials and/or can be covered by an oleophilic abrasion resistant coating 73. Depending upon their configuration, i.e., breadth, width or diameter, the size of the apertures 72 of the belt thus produced, preferably is within the range of 0.05 to 0.50 inches, and more preferably within the range of 0.1 to 0.3 inches. Solid particles of conventional ore slurries pass through the apertures 72 with increasing difficulty as the size of the apertures diminishes below these minimum dimensions.
The size of the apertures is influenced to a large degree by the mean and the maximum particle size of the solids of the slurry 59, the concentration of solids in the slurry, the vise costly of the oleophilic phase, the affinity of the oleophilic phase for the oleophilic surface 1 of the belt, the size of the oil phase particles, and the rate of slurry flow passing through the belt apertures. The size of the apertures along the belt, further, is influenced by the velocity of the moving belt surface relative to the velocity of the slurry passing through the apertures. The surface speed of the belt will preferably be between 0.1 and 10.0 feet per second. For these reasons the physical character-is tics of the slurry to be separated will determine to a degree the actual size of the apertures of the belt and the surface speed of the belt.
The mesh belt can be made from steel wires, stainless steel wires or from other thin rods or strands that are strong enough so that the belt can be used for extended periods in a commercial plant employing this process. A
coating 73 of vulcanized neoprene or other oil resistant oleophilic, abrasion resistant and I strong material can be used to provide a bond between the members 80 across the belt and the members 81 along the belt. It is not intended that this invention be limited to the type of -22~
1 belt. Other kinds of mesh or perforated belt that can be used for the process will be apparent to those skilled in the art. Nylon mesh belts as is, or covered with an oleophilic coating, have been used successfully.
Means should be provided for collecting the adhering collector-mineral combination from the belt surface and out of the belt apertures.
This is preferably done by the use of rollers as shown in figure 3. Referring to that figure, the collector-mineral combination is forced through apertures 72 with a transfer roller 75 and collected with a collector roller 76. The collector-mineral combination on the collector roller can be scraped therefrom with a doctor blade 77, for collection in a hopper 78 from where it can be pumped or conveyed to a central gathering point for subsequent refining. The collector rollers normally are driven to provide motion to the belt.
The transfer rollers are driven or left to idle.
It has been found that the rollers can suitably be formed from a resilient oil resistant material such as neoprene, urethane, etc. The -23- en 1 collector roller only works effectively if its surface is oleophilic but the transfer roller 75 may be either oleophilic or oleophobic. If the transfer roller is oleophobic, it will push the oil phase through the apertures 72 without leaving much residual collector on its own surface, but it will not do much to aid the recovery roller in removing the collector out of the belt apertures 72. Open apertures are needed to allow the subsequent slurry passage through the belt in the separation stage. When the belt is very thin, the recovery roller is able to attract enough collector from the belt to open the apertures by itself, a hydrophilic transfer roller can then be used. In most commercial applications where the required belt strength necessitates a somewhat thicker belt, an oleophilic transfer roller 75 will be preferred. Such a roller pushes the bitumen through the apertures onto the recovery roller but subsequently it withdraws some of the collector out of the apertures, keeping its surface covered with mounds 79 of collector and aiding the collector roller 76 in opening up the apertures. An oleophilic -24~
1 transfer roller 75 may be scraped with a doctor blade to provide an additional stream of collector-mineral combination and increase somewhat the rate of recovery of the said combination.
The mineral can be recovered from the collector-mineral combination by any suitable means, such as by solvent extraction, using sol-vents for the collector such awl for example, Bunsen, Tulane, acetone, alcohols and the like, and mixtures thereof, or by the use of thermal extraction as by heating the mixture to remove the collector and leave the solid mineral particles behind. Chemical treatment to break the associa-lion of the collector with the mineral particles followed by centrifugation or other separation techniques may also be utilized.
The desired minerals can thus be recovered substantially free of the guying and can be used directly in their intended applique-lions. Any collector recovered from the separation step may be recycled and used again in the initial slurring step of the process.
(keynoted on page 24) -25~ '7 A particularly preferred embodiment of the invention comprises recovering the minerals from mixtures containing it and guying wherein the crushed ore is slurries with water, and an oleophilic material which may be present in the ore itself, such as bitumen in tar sands, or may be added to the slurry.
In this embodiment, the crushed ore particles, preferably between 20 and 250 mesh in size, are slurries with water, and the oleophilic material, preferably in a rotating tumbler, to effect a thorough mixing of the components and provide an opportunity for the mineral particles to come in contact with the oleophilic material.
Steam may be used as well or other materials, such as suspension agents, stabilizers, and the like, may be added as desired to assist in the formation of the slurry. While water is the desired slurry medium, it is also possible to utilize solvents or water-solvent mixtures to form the desired slurry.
The amount of water used in the slurry 1 may vary over a wide range. The amount o-f water should be sufficient to give the mixture sufficient fluidity so there will be proper mixing in the formation of the slurry and sufficient fluidity for passage through the aperture surface. In general, the amount of water employed will vary from about 0.1 to 5.0 pounds of water per pound of crushed ore.
The desired temperature to be used in the formation of the slurry will also vary over a wide range and is dictated to a degree by con-gems for economics. Temperatures generally range from about 85F. to 212F. A slurry with a 50 percent water content by weight, produced at 120 F.
is an acceptable compromise for many of the ore feed stocks. What is important is that sufficient water be present to allow all slurry components to be mixed at the conditioning temperature.
The oleophilic material to be added to the slurry can be of those described above, as long as it has the desired oleophilic properties to attract and attach to the desired mineral particles and in combination therewith to be attached -27- I '7 1 to the oleophilic aperture surface.
Oleophilic materials to be used in the preferred embodiments include the bitumens and heavy oils already present in some ores. Portico-laxly preferred oleophilic materials include the hydrocarbon compositions having a molecular weight between about 500 and 50,000, and still more preferably those of the group consisting of bitumens, heavy oils, crude oils, kerosene, pine oils, and hydrocarbon polymers derived from olefins and dolphins.
The oleophilic material to be used may be a single component or a mixture of two or more of the above-defined materials. As noted above, under special cases, such as with tar sands, oil shales, heavy crude oil deposits, and the like, the oleop~lilic material may already be included with the mineral ore particles and additional material need not be added to the slurry.
The amount of the oleophilic material to be present in the slurry may vary over a wide range depending on the concentration of the desired mineral to be recovered, nature of the -28~
1 bond -to be employed, temperature and fluidity of the slurry. In general, the amount of the Leo-Philip material will vary from about 1 percent to about 150 percent of the weight of the ore being treated.
The desired slurry is prepared by intro-during the water, and oleophilic collector and crushed mineral ore into a rotating tumbler so as to effect a thorough mixing of the components and provide an opportunity for the mineral particles to come in contact with the oleophilic material.
Equipment other than the rotating -tumbler can also be used as long as the desired contact is accomplished. Residence times of about 1 to 30 minutes in the tumbler should be sufficient to effect the needed contact between the mineral particles and the oleophilic material.
Oversized particles, such as rocks, lumps of clay, debris, etc. from the crushed mineral ore are then removed as shown in US. 4,224,138 before bringing the slurry in contact with the aperture belt or disc so as to prevent clogging of the openings with such large particles.
-29- f~.`3~
1 The slurry is then brought into contact with the oleophilic treated aperture wall as shown in US. 4,224,13~, and the mineral particles recovered from the oleophilic layer collected on the surface of the aperture wall.
The process of the invention can be used to recover a great variety of different minerals from mixtures containing the same. The metals may occur in the ore as free metals or in combination with other chemical radicals, such as sulfides, and the like.
Preferred minerals to be recovered by the process of the invention are those which are substantially free of oxides on their surfaces, and contain heavy metals, and particularly those having molecular weights between 35 and 250.
Compounds containing these metals, and especially their sulfides, halides and manganates, are particularly effective in the process of the invention.
A few metals, such as gold, occur naturally as free metals but most of the metals occur in ores where they are bound in crystalline _30- Jo I
1 structure with other chemical groups or radicals, such as the sulfide, and the like radicals.
As indicated above, while some minerals may not be oleophilic per so, they can be made oleoph fig by use o-f activators or collectors.
examples of ore that can be treated by the process of the invention include, among others, ores con-twining titanium such as illuminate, magnetize and futile; those containing manganese which include psilomelane, pearliest, manganite, rhodochrosite, oligonite; those containing chromium, which include cremate, serpent~nites; those containing nickel, which include pentlandite, chalcopyrite, pyrrhotite, garnierite, nepuite; those containing cobalt, which include lunate, cobaltite, smaltite, heterogeneity; those containing -tungsten include shalt, wolframite; those containing molybdenum include molybdenite, chalcopyrite; those containing vanadium include paternity, vendetta, vanadinite, descloizite, titanomagentite, carnotite; those containing lead and zinc include Golan, sphalerite, chalcopyrite, pyrites castrate; those containing mercury include cinnabar; those containing antimony 1 include stibni-te, quartz; and -those containing bismuth include bismuthinite; those containing aluminum include hydragillite, boehmite; those containing beryllium and lithium include Barlow, spodumene; those containing magnesium include carnality, magnesite and dolomite; those con-twining gold include gold tellurides; those containing silver include Argentine, prostate, pyrargirite; those containing platinum group metals include chromespinellides and hortonolite;
those containing uranium and thorium include urbanite, vendetta, uraninite, Minnesota; those containing tantalum and niobium include tantalize, columbine, pyrochlore-, loparite, microlite; those containing zirconium and rare earths include bade-Lotte, Minnesota, xenotime; and other deposits containing sesame, germanium, thallium, scandium, cadmium, selenium, tellurium, rubidium, gallium, indium, hafnium and rhenium.
The process can also be used to remove minerals such as goat from other solid particles, such as sand, where the purified solid particles are the desired product. In many cases, for example, 1 deposits of construction sand contain contaminate in components, such as coal, which interfere with the use of the sand in formation of concrete as it tends to weaken the structure. In this case, the process of the invention can be used to remove the coal from the sand particles and the product recovered from the aqueous phase is the more desired material. This illustrates the reverse application of the process wherein the desired material may be that remaining in the aqueous phase and the purpose is to remove the material being attracted to the oil phase.
The process of the invention can also be used to advantage in the purification of sludge ponds at industrial sites where the sludge contains undesirable oleophilic products, such as toxins, PUB, and the like, which can be removed by use of the collectors as in the above-described process of the invention.
The process may also be used to remove proteins from mixtures containing proteins and like substances.
The process may also be used in the prepare-1 lion of medicines.
While the process of the invention has been described chiefly in terms of a process for preparing slurries directly in a conditioning drum, the process can also be used for treatment of suspensions or emulsions of oil, tar or hydra-carbon produced from a heavy oil, tar sand or oil shale deposits, by steam injection or by no-lofting or combustion which may contain precious minerals, by utilizing such compositions directly in the process as described above.
To illustrate the process of the invention, the following examples are given. It should be understood, however, that they are given only in the way of illustration and in no way limit the scope of the invention.
EXAMPLE I
This example illustrates the separation of mica flakes from a mixture of mica and silica sand.
A mixture made up of 10 pounds of mica flakes and 90 pounds of silica sand is added to water slurry made up of 30 pounds of water and '7 I
1 25 pounds of heavy oil collector and the mixture tumbled in a rotating tumbler at 100C. After about 10 minutes of tumbling) the mica becomes associated with the heavy oil in the oil phase.
The slurry is then introduced into a water bath which contains an aperture endless belt prepared from vulcanized neoprene arranged as disclosed in the above-described preferred embodiment.
Most of the sand drops through the apertures while most of the heavy oil containing the mica flakes in the oil phase is collected on the neoprene belt. The material that passed through the first flight of the belt passed through the send flight and any Howe oil remaining in the slurry is recovered at the second flight on the neoprene belt. It is found that there is a very high recovery of the mica flakes in the heavy oil and little mica is found in the sand tailings.
EXAMPLE II
This example illustrates the recovery of small amounts of titanium and zirconium from tailings obtained from the hot water process for recovering oil from tar sands which process is ho low ill co~ercial operatioll. The ore being treated contained traces of zirconium and titanium. With suckle a process 8 to 15 percent of the bitumen still remains with the solid ore particles in the tailings.
Tailings from the above process containing 60.0 percent solids, 39.0 percent water and 1.0 percent bitumen was passed through an oleophilic aperture wall surface as show in United States 49236,995. The bitumen collected on the screen was removed and treated to recover the zirconium and titanium. The bit-men collected from these tailings was found to contain more than three times as much zirconium and titanium percentage by weight as compared with the bitumen product of the hot water process.
Another important application of the instant invention relates to the recovery of futile and aunts from the primary and secondary tailings of common-coal hot water extraction mined oil sands plants. The process used in these oil sands plants currently in operation in Fort McMurray, Alberta is based upon the Clark Hot Water Process wherein mined oil sand feed stock is mixed with steam and water in a conditioning tumbler to produce a slurry. Oversize rock, clay lumps and tramp are removed from this slurry at a temperature of approximately 185F
and then the slurry is diluted with hot water and is pumped to a primary swooper-lion vessel when bitumen floats to the top of the vessel and is skimmed off as a primary froth product. Sand, silt, clay, water and bitumen that will not float fall to the bottom of the primary separation vessel and are discarded as primary tailings. A stream of silt, clay and bitumen suspended in water, called the mid-doings stream, is removed from the middle of the primary separation vessel to maintain an effective balance in this vessel. The middlings stream is conveyed to conventional froth flotation vessels where the middlings are aerated to pro-dupe a secondary bitumen froth product, and a secondary tailings stream that is discarded. The primary bitumen froth and the secondary bitumen froth are come '7 brined, mixed Thea a delineate and centrifuged to produce a clean bitumen product for use as upgrading and refining feed stock and a centrifugal tailings stream.
It is known that the centrifugal tailings contain heavy minerals, in particular ores of titanium and of zirconium, and several patents have been granted for the recovery and processing of these minerals, in particular Canadian patents:
861,580 and 879,996 and 927,983 as well as U.S.A. patents 3,656,938 and 3,990,885 and 4,138,467 and 4,150,093.
However, while processing primary and secondary tailings, it has been discovered that these tailings also contain ores of titanium and zirconium in abundance. One important finding of pilot plant studies has been that in par-titular the primary tailings contain approximately 0.3% bitumen which may be used to collect futile, aunts and zircon from these tailings.
The titanium ores that may be recovered from centrifugal tailings generally are high in illuminate and low in futile. In contrast, the titanium ores which may be recovered from primary tailings and from secondary tailings by the instant invention are high in futile and very low in illuminate. On the world market futile is worth approximately 20 times as much per ton as illuminate.
In pilot plant tests, two 45 gallon drums of primary tailings were used as feed stock for the process of the instant invention. This feed stock con-twined 0.3% bitumen, 75.7% solids and 24.0% water by weight and was conveyed to a tumbler containing oleophilic free bodies. The actual free bodies used were 1/2 inch diameter spheres of steel, coated with cadmium, spheres of neoprene mixed with lethargy also 1/2 inch in diameter and 1/4 inch diameter spheres of polyolefin. About equal amounts of each type of sphere were used in the tumbler.
It has been found that shapes other than spheres may be used as is discussed in Canadian patent application 333,832. The tumbler was 18 inches in diameter and 18 inches long and was filled with free bodies, leaving only about 20% free-to board of the drum volume free from oleophilic bodies to permit effective tub-lying and mixing of the free bodies with the feed stock which entered the drum con-tenuously during the test run at approximately 100 pound per hour and which left the drum from the opposite end at the same rate. The free bodies remained in the drum throughout the test. While the feed stock mixed in the drum with the free bodies its dispersed bitumen came or remained in contact with futile, aunts and zircon in the feed stock and then collected into streamers of bitumen that left the drum at the exit end along with water suspended solids as a stream. This stream of bitumen agglomerated tailings next was passed to an aperture Leo-Philip belt separator such as described in Canadian patent application 333,640.
(Similar separators are described in Canadian patent applications 333,641 and 333,830). In this separator the water suspended solids passed through the apertures of the oleophilic belt and the bitumen with the contained futile, aunts and zircon collected on the surface of the oleophilic belt. The belt revolved continuously and the collected bitumen was subsequently removed from the belt surface as a bitumen stream that contained a considerable amount of futile, aunts and zircon as well as other solids such as sand, silt and clay.
The water suspended solids stream analyzed 0.1% bitumen, 69.5% solids and 30.4%
water by weight. The bitumen stream analyzed 38.3% bitumen, 41.7% solids and 20.2% water by weight.
The solids were then removed from the bitumen of the bitumen stream with a solvent that diluted the bitumen and washed the solids and then the solids were dried and analyzed. No illuminate was found in the dried solids but futile content of these solids was approximately 10% along with approximately 0.6% zip-con, and other materials such as aunts, china clay, and quartz.
A magnetic separation test demonstrated that futile could be removed readily from most of the other materials present in these dried solids.
Lyle such additional tests were not conducted, there is no reason that magnetic separation should not be practiced on the solids fraction of the bitumen product while it is still wetted or suspended in the solvent used for washing the bitumen from these solids.
Another method for recovering futile from the bitumen product of the instant invention is to heat the bitumen in an inert atmosphere to vaporize and crack the bitumen to produce an overhead hydrocarbon vapor that is recovered subsequently and leave a residue of coke on the solids particles. Then burning these solids particles with air or oxygen to remove the coke and produce an ash or solids residue that is relatively carbon free and from which the futile may then be extracted magnetically either while the solids are a dry powder or while suspended in water with or without suitable reagents.
Thus the instant invention is of particular advantage for recovering the more expensive titanium ores, such as futile, from the primary and secondary tailings of a hot water oil sands extraction process.
In addition, the process may also be used to recover futile, aunts and zircon from mined oil sands by a similar process. In this case the feed stock for the agglomerating tumbler, containing the oleophilic free bodies, is a slurry of mined oil sand and water that has been prepared previously in a condo-toning tumbler as described above. The process thereafter is similar to the process used for recovering futile from primary tailings described above. The same process may also be used with secondary tailings as feed stock to recover futile from secondary tailings.
Thus the process for recovering futile in the instant invention con-sits of tumbling the feed stock in a tumbler to permit bitumen and futile to become intimately mixed with each other in the presence of water and solids.
Free bodies may be used in the drum but do not have to be used to assist bring-Lo q.31 i' in the bitumen in contact with the futile in the feed stock. The futile in the process becomes part of the bitumen fraction and when the thus prepared feed-stock stream is separated with an aperture oleophilic belt separator the futile and aunts and zircon are part of the bitumen products stream. Thereafter the bitumen stream is separated unto its components and futile is extracted as one of the valuable minerals. Aunts and zircon are additional valuable minerals that are extracted.
Additional test were conducted to determine the need for a drum con-twining oleophilic free bodies in the process to collect futile from the tailings into the bitumen. It was found that without the use of such a drum to treat the tailings before separation by the aperture oleophilic belt the futile content in the bitumen products stream was less than when such a drum was used. The relative amounts were not measured but it appeared that with the drum about I
more futile was produced than without the drum.
From the test work that has been conducted with primary tailings, it has been concluded that the bitumen particles suspended or contained in the prim-cry and secondary tailings of a hot water extraction process are loaded with solids and minerals such as futile and zircon. If this were not so, the bitumen would float and rise to the top of the extraction vessels of the Hot Water Pro-cuss. However, the bitumen that finds its way into the primary and secondary tailings will not float but sinks along with the sand and silt to the bottom of the vessel. When these tailings are then processed with a method that does not rely upon bitumen flotation to achieve the separation, such as with an aperture oleophilic wall separator, the recovered bitumen is high in valuable titanium and zirconium ores such as futile, aunts and zircon.
During the hot water extraction process not all the futile, aunts and zircon become associated with the bitumen but some of these minerals are found in the tailings separate from the bitumen. Therefore, when these tailings are tumbled in a drum in the presence of oleophilic free bodies, this tumbling helps to contact these minerals with bitumen in these tailings to cause these minerals such as futile, aunts and zircon and possibly illuminate to become part of the bitumen phase which is then recovered subsequently in the separation step.
The above specifications refer to futile, aunts and zircon recovery from tailings or sludge of a Hot Water Extraction Process plant. However, the instant invention has application as well in the recovery of these valuable minerals directly from a prepared slurry of mined oil sand without passing this slurry first through the primary and/or secondary extraction vessels of the Hot Water Process. or this aspect of the instant invention, a slurry of mined oil sand and water and/or steam is prepared which is then passed directly through the the tumbler with oleophilic free bodies and then through the aperture oleophilic sieve separation apparatus for recovery of the bitumen and for recovery of the valuable minerals such as futile, aunts and zircon directly with the bitumen, and then the separation of these valuable minerals from the bitumen and the sepal ration of the titanium minerals therefrom by magnetic separation as described above. Alternately the slurry may be separated without the use of a tumbler con-twining oleophilic free bodies. In that case the prepared slurry is passed dip neatly to the aperture oleophilic wall for separation, bitumen recovery and titanium minerals recovery as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred apparatus to be used in the process of the invention is that shown in US.
4,236,995 and U. S. 4,224,138. Figure 1 is a per-spective view showing an apparatus patterned after that shown in US. 4,224,138 for conducting the process of the invention wherein the aqueous slurry containing the water, stream, crushed ore and oleophilic material is passed through an aver-lure surface which is in the form of a rotating 1 belt contained within a water bath.
Figure 2 and PA are views of a section of an aperture oleophilic sieve belt in the form of a meshed construction.
Figure 3 is a schematic illustration of one method for recovering the mineral-oleophilic material combination from the aperture belt or disc using two rollers.
DETAILED DESCRIPTION OF THE INVENTION
The first step in the process of the invention involves insuring that the mineral particles in the mixture have an oleophilic sun-face of sufficient area to effect attraction of the particles to an oleophilic aperture surface.
As used herein "oleophilic" refers to those surfaces or materials which are attracted to and wettable with oil, as distinguished from oleophobic wherein the surfaces are not so attracted or wetted with oil.
It has been found that precious mineral particles tend to be naturally oleophilic and have oleophilic surfaces unless they are coated with slime or with oxides of iron or other metallic 1 oxides, or with films of hydrophilic matter.
Metals -that are not easily oxidized such as tin also tend to have oleophilic surfaces. Broadly speaking sulfide minerals are or can be made to be oleophilic but oxides, carbonates, silicates and surfaces are mostly oleophilic. Graphite is oleophilic, diamonds are hardly oleophilic and copper is hardly oleophilic. Silver in its native state is oleophilic.
Gold particles, particularly when flaky or in piety form have oleophilie surfaces.
In some cases, the gold particles may be coated with iron oxides or clay and such coatings should be removed by abrasion to expose the oleophilie surface. Silver is also found in small flaky form wherein the surfaces are oleophilic unless coated with material such as iron oxide and clay which can be removed as by abrasion to make the surfaces oleophilie.
Those ours are not naturally Leo-Philip can be made oleophilic by contacting them with what is termed an activator. These materials normally act by absorbing on the surface/solution 1 interface, thereby providing sites for the adsorb-lion of the collector species. For example, addition of oxygen to a gold bearing water sup-pension will increase the oleophilic attraction of gold.
Minerals can also be made oleophilic by the addition of agents known as collectors.
These materials provide the surface of the mineral that is to be recovered with an oily film that makes the mineral oleophilic. Preferred collectors are those which add to the mineral surface to the exclusion of the guying and which have a hydrocarbon chain or a hydrocarbon ring in one part of the molecule or at one end of the molecule and at the other end have a polar element that is likely to combine with the mineral surface.
For example, oleic acid is a preferred collector.
It has a fairly long hydrocarbon chain and at one end of the molecule there is the carboxyl radical which reacts with the mineral surfaces. The same is true of xanthates.
Other examples of the collectors include heavy oils, bitumen, fuel oils, long chain fatty 1 acids, long chain amine, polymeric materials of low molecular weight derived from olefinic and diolefinic compounds, and the like, and mixtures thereof.
The oleophilic collector material added can be ionizing compounds which dissociate into ions in aqueous mixtures and act by attaching to the surface of the desired mineral particles and thereby impart the desired oleophilic pro-parties. The oleophilic collector may also be long chain chelates type materials which enter into a weak chemical bond with the mineral particles. The added oleophilic collector can also be non-ionizing compounds or compositions which are practically insoluble and effect the desired results by forming a thin film on the surface of the mineral particles and thus impart the desired oleophilic character to the resulting combination.
Preferred ionizing collectors to be used are those which are asymmetric in structure and have a non-polar hydrocarbon group attached to the molecule. The ionizing collectors may be ho I
1 anionic or cat ionic or mixtures thereof. examples of these include, among others, organic acids such as oleic acid, linoleic acid, sodium owlet, sodium linoleate, long chain sulfates and sulfonates, xanthates and dithiophosphates, long chain amine, long chain halides, and the like.
The exact ionic collector to be used in the process will depend chiefly upon the electron static attraction between the polar head of the collector and the charged electrical layer on the mineral surface, and a few routine tests will review the most efficient combination of mineral and collector to be utilized.
The non-ionic collectors which generally function by coating the surface o-f the mineral particles may be of any suitable type as long as the necessary attraction to the mineral particle is provided. Examples of suitable materials include, among others, bitumen, heavy oil, diesel oil, crude oil, kerosene, and the like and mixtures thereof.
The first step in the process then is to be sure that the mineral particles have an 1 oleophilic surface. This can be accomplished by selecting mineral particles which by nature have oleophilic surfaces or can be made so by the addition of an activator or by the addition of an activator and a collector or by the addition of a collector only. The exact prove-dune to be used will depend upon the mineral being separated.
The mineral surface should also be large enough that the oleophilic surface will be attracted to the oleophilic aperture surface.
If the area is not large enough it can be increased by grinding or crushing to expose more of the mineral surface. The crushed ore should preferably have a particle size Owe 20 mesh or less and more preferably from 20 mesh to 250 mesh.
The crushing can be accomplished by any conventional technique, such as jaw crushers, gyrator crushers or rolls, and if smaller particles are desired they may be obtained by use of ball mills or similar equipment.
The mixture containing the mineral particles having the oleophillc surface is then I I
1 treated to separate the mineral particles from the guying. This may be accomplished in a variety of ways. A preferred technique comprises passing a mixture of mineral particles having the oleophilic surface and the guying, and preferably a liquid carrier such as water, through an oleophilic aperture wall or barrier or belt which is coated with an oleophilic material, such as oil, bitumen or grease, which captures the oleophilic mineral particles while permitting the hydrophilic guying particles to pass through the apertures. The oil oleophilic material is then removed from the aperture wall and is refined to recover the mineral and the aperture wall is again covered with fresh oleophilic material, such as oil, bitumen or grease to capture more mineral particles in the subsequent sieving.
Another preferred embodiment comprises mixing the mixture or mineral particles having the oleophilic surfaces and the guying with an aqueous medium containing an oleophilic material so that the mineral particles become coated with a thick coating of the said oleophilic material -14~ C~3~^~
1 and the hydrophilic guying becomes coated with water. This is preferably accomplished by tumbling the mineral particles, guying, water and oleophilic material in a drum for a sufficient period to insure that the mineral particles are coated with a thick coating of the oleophilic material. The slurry that is thus prepared is then passed through the aperture oleophilic wall wherein the mineral particles coated with the oleophilic material are attracted to the oleophilic surface of the aver-lured wall, and the hydrophilic guying passes through the apertures. The captured oleophilic material containing the mineral particles is then removed from the aperture surface and the process repeated. There is no need to apply a thick coating of oleophilic material to the oleophilic aperture surface in this case and the thick coating is already on the mineral particles.
Another preferred embodiment comprises adding an emulsion of oleophilic material, such as oil or bitumen, and water to the mixture of mineral particles and guying, and after thorough mixing, adding an emulsion breaker to the mixture.
-15~ I
1 The emulsion used in this case possesses the Leo-Philip material as the dispersed phase and the water as -the continuous phase. When the emulsion breaker is added to the mixture, oil phase particles are free to find the oleophilic surfaces of the mineral particles and adhere thereto. Such particles are then coated with a thick coating of the oleophilic material. The resulting slurry is then passed through the aperture oleophilic wall wherein the mineral particles coated with the Leo-Philip material are attracted to the oleophilic surface of the aperture wall, and the hydrophilic guying passes through the apertures of the said wall. The captured oleophilic material containing the mineral particles is then removed from the aperture surface and the process is repeated.
Another preferred embodiment involves a technique for use when the mineral ore itself contains an oleophilic material. For example, in many cases tar sands and shale oil particles contain mineral particles as well as the oleophilic bitumen or heavy oil. In these cases, the mineral ore particles which contain the desired mineral 1 particles having oleophilic surfaces, the guying and the oleophilic material such as bitumen, heavy oil and the like, are tumbled in a drum in the presence of water and preferably steam, and the mineral particles are coated with a thick coating of the oleophilic material such as bitumen or heavy oil. When this aqueous slurry is passed through the aperture oleophilic wall, the mineral particles coated with the oleophilic material are captured by the wall and the guying passes through the apertures. The mineral particles and Leo-Philip material can then be removed from the wall and the mineral particles recovered.
The aperture wall having the oleophilic surfaces to be used in the above-process of the invention may be of any suitable construction and arrangement as long as it provides openings for the gangueparticles to pass through and an Leo-Philip surface to attract the mineral particles.
Suitable apparatus for -this purpose comprise those shown in US. 4,236,995 and US. 4,224,138. The apparatus preferably has the aperture wall in the form of a screen the cables of which are -17~ 7 1 coated with or made up of an oleophilic material.
The screen may be immersed, not immersed or partly immersed in a water bath.
The preferred apparatus to be used as shown in US. 4,224,138 is illustrated in attached Figure 1.
The apparatus shown in Figure 1 consists of an endless aperture conveyor belt having a top flight 65 and a bottom flight 64 stretched between two conveyor end rolls 51, 52 in a water bath 63 having a water level 42. These end rolls may be crowned to keep the belt running centrally on the end rolls. Both sides of this belt and the wall of the apertures are oleophilic. Slurry from the tumbler is conveyed through conduit 41 into hoppers 43, 44, 45 and 46, the bottom portions of which can be, but do not have to be submerged below the surface of water 42 for the purpose of evenly distributing it at a multiplicity of toga-lions along the belt. Collector recovery stations are mounted along the belt on both flights at a multiplicity of locations 47, 48, 49, 50, 53, 54, 55 and 56.
f~J of 7 1 The separation and collector recovery at the various locations along the belt is similar.
or this reason it is described here for hopper 44 and recovery stations 49 and 54 which together form one separation location. The slurry 59 leaves hopper 44 in the form of a ribbon that is almost as wide as the belt and with a thickness and velocity representing a slurry flow rate that can be conveniently separated by the belt. It falls through the water 42 and is diluted by it until it encounters -the top belt flight 65 where water and the solids in the water phase pass through the apertures of the belt while the collector is attracted to the oleophilic surface of the belt.
The top flight 65 of the belt which is in motion from the right to left carries this slurry along for some small distance before the separation is complete. Baffles 57 or other stirring means are provided to create turbulence in the water above the belt and to disturb any unseparated slurry resting on the belt surface.
The collector-mineral composition is recovered from the belt at location 49. The slurry 2~3~
1 58 that has passed through the apertures of the top flight settle downward to the bottom belt flight. Baffles 60, 61, 70 and 71 serve to contain this slurry so that it will drop onto the bottom conveyor flight. As the slurry passes through the bottom flight 64 water and particulate solids 62 drop to the bottom of the water bath 63 from where they are removed. Substantially all of the collector-mineral composition that was not recovered at the top flight is attracted to the oleophilic surface of the bottom flight 64, which is in motion from left to right. It is recovered at location 54. The solids 62 and the water are removed from the bottom of the water bath 63 at a rate such that a constant water level 42 is maintained in the bath. A pump, auger, or some other mechanical device is used for this purpose.
The aperture oleophilic belt is an important part of the above-described apparatus.
Construction details of this belt are shown in Figure 2 and PA. The belt could consist of rota-lively more rigid members 80 across the belt that are woven into a mesh belt by the use of -20- .29'~
1 relatively more flexible members 81 along the belt. The flexible members 81 consist of cable constituting two or more strands which enclose each member 80 across the belt and which are twisted to maintain the desired spaced relation-ship between the members 80. This belt can be made from oleophilic materials and/or can be covered by an oleophilic abrasion resistant coating 73. Depending upon their configuration, i.e., breadth, width or diameter, the size of the apertures 72 of the belt thus produced, preferably is within the range of 0.05 to 0.50 inches, and more preferably within the range of 0.1 to 0.3 inches. Solid particles of conventional ore slurries pass through the apertures 72 with increasing difficulty as the size of the apertures diminishes below these minimum dimensions.
The size of the apertures is influenced to a large degree by the mean and the maximum particle size of the solids of the slurry 59, the concentration of solids in the slurry, the vise costly of the oleophilic phase, the affinity of the oleophilic phase for the oleophilic surface 1 of the belt, the size of the oil phase particles, and the rate of slurry flow passing through the belt apertures. The size of the apertures along the belt, further, is influenced by the velocity of the moving belt surface relative to the velocity of the slurry passing through the apertures. The surface speed of the belt will preferably be between 0.1 and 10.0 feet per second. For these reasons the physical character-is tics of the slurry to be separated will determine to a degree the actual size of the apertures of the belt and the surface speed of the belt.
The mesh belt can be made from steel wires, stainless steel wires or from other thin rods or strands that are strong enough so that the belt can be used for extended periods in a commercial plant employing this process. A
coating 73 of vulcanized neoprene or other oil resistant oleophilic, abrasion resistant and I strong material can be used to provide a bond between the members 80 across the belt and the members 81 along the belt. It is not intended that this invention be limited to the type of -22~
1 belt. Other kinds of mesh or perforated belt that can be used for the process will be apparent to those skilled in the art. Nylon mesh belts as is, or covered with an oleophilic coating, have been used successfully.
Means should be provided for collecting the adhering collector-mineral combination from the belt surface and out of the belt apertures.
This is preferably done by the use of rollers as shown in figure 3. Referring to that figure, the collector-mineral combination is forced through apertures 72 with a transfer roller 75 and collected with a collector roller 76. The collector-mineral combination on the collector roller can be scraped therefrom with a doctor blade 77, for collection in a hopper 78 from where it can be pumped or conveyed to a central gathering point for subsequent refining. The collector rollers normally are driven to provide motion to the belt.
The transfer rollers are driven or left to idle.
It has been found that the rollers can suitably be formed from a resilient oil resistant material such as neoprene, urethane, etc. The -23- en 1 collector roller only works effectively if its surface is oleophilic but the transfer roller 75 may be either oleophilic or oleophobic. If the transfer roller is oleophobic, it will push the oil phase through the apertures 72 without leaving much residual collector on its own surface, but it will not do much to aid the recovery roller in removing the collector out of the belt apertures 72. Open apertures are needed to allow the subsequent slurry passage through the belt in the separation stage. When the belt is very thin, the recovery roller is able to attract enough collector from the belt to open the apertures by itself, a hydrophilic transfer roller can then be used. In most commercial applications where the required belt strength necessitates a somewhat thicker belt, an oleophilic transfer roller 75 will be preferred. Such a roller pushes the bitumen through the apertures onto the recovery roller but subsequently it withdraws some of the collector out of the apertures, keeping its surface covered with mounds 79 of collector and aiding the collector roller 76 in opening up the apertures. An oleophilic -24~
1 transfer roller 75 may be scraped with a doctor blade to provide an additional stream of collector-mineral combination and increase somewhat the rate of recovery of the said combination.
The mineral can be recovered from the collector-mineral combination by any suitable means, such as by solvent extraction, using sol-vents for the collector such awl for example, Bunsen, Tulane, acetone, alcohols and the like, and mixtures thereof, or by the use of thermal extraction as by heating the mixture to remove the collector and leave the solid mineral particles behind. Chemical treatment to break the associa-lion of the collector with the mineral particles followed by centrifugation or other separation techniques may also be utilized.
The desired minerals can thus be recovered substantially free of the guying and can be used directly in their intended applique-lions. Any collector recovered from the separation step may be recycled and used again in the initial slurring step of the process.
(keynoted on page 24) -25~ '7 A particularly preferred embodiment of the invention comprises recovering the minerals from mixtures containing it and guying wherein the crushed ore is slurries with water, and an oleophilic material which may be present in the ore itself, such as bitumen in tar sands, or may be added to the slurry.
In this embodiment, the crushed ore particles, preferably between 20 and 250 mesh in size, are slurries with water, and the oleophilic material, preferably in a rotating tumbler, to effect a thorough mixing of the components and provide an opportunity for the mineral particles to come in contact with the oleophilic material.
Steam may be used as well or other materials, such as suspension agents, stabilizers, and the like, may be added as desired to assist in the formation of the slurry. While water is the desired slurry medium, it is also possible to utilize solvents or water-solvent mixtures to form the desired slurry.
The amount of water used in the slurry 1 may vary over a wide range. The amount o-f water should be sufficient to give the mixture sufficient fluidity so there will be proper mixing in the formation of the slurry and sufficient fluidity for passage through the aperture surface. In general, the amount of water employed will vary from about 0.1 to 5.0 pounds of water per pound of crushed ore.
The desired temperature to be used in the formation of the slurry will also vary over a wide range and is dictated to a degree by con-gems for economics. Temperatures generally range from about 85F. to 212F. A slurry with a 50 percent water content by weight, produced at 120 F.
is an acceptable compromise for many of the ore feed stocks. What is important is that sufficient water be present to allow all slurry components to be mixed at the conditioning temperature.
The oleophilic material to be added to the slurry can be of those described above, as long as it has the desired oleophilic properties to attract and attach to the desired mineral particles and in combination therewith to be attached -27- I '7 1 to the oleophilic aperture surface.
Oleophilic materials to be used in the preferred embodiments include the bitumens and heavy oils already present in some ores. Portico-laxly preferred oleophilic materials include the hydrocarbon compositions having a molecular weight between about 500 and 50,000, and still more preferably those of the group consisting of bitumens, heavy oils, crude oils, kerosene, pine oils, and hydrocarbon polymers derived from olefins and dolphins.
The oleophilic material to be used may be a single component or a mixture of two or more of the above-defined materials. As noted above, under special cases, such as with tar sands, oil shales, heavy crude oil deposits, and the like, the oleop~lilic material may already be included with the mineral ore particles and additional material need not be added to the slurry.
The amount of the oleophilic material to be present in the slurry may vary over a wide range depending on the concentration of the desired mineral to be recovered, nature of the -28~
1 bond -to be employed, temperature and fluidity of the slurry. In general, the amount of the Leo-Philip material will vary from about 1 percent to about 150 percent of the weight of the ore being treated.
The desired slurry is prepared by intro-during the water, and oleophilic collector and crushed mineral ore into a rotating tumbler so as to effect a thorough mixing of the components and provide an opportunity for the mineral particles to come in contact with the oleophilic material.
Equipment other than the rotating -tumbler can also be used as long as the desired contact is accomplished. Residence times of about 1 to 30 minutes in the tumbler should be sufficient to effect the needed contact between the mineral particles and the oleophilic material.
Oversized particles, such as rocks, lumps of clay, debris, etc. from the crushed mineral ore are then removed as shown in US. 4,224,138 before bringing the slurry in contact with the aperture belt or disc so as to prevent clogging of the openings with such large particles.
-29- f~.`3~
1 The slurry is then brought into contact with the oleophilic treated aperture wall as shown in US. 4,224,13~, and the mineral particles recovered from the oleophilic layer collected on the surface of the aperture wall.
The process of the invention can be used to recover a great variety of different minerals from mixtures containing the same. The metals may occur in the ore as free metals or in combination with other chemical radicals, such as sulfides, and the like.
Preferred minerals to be recovered by the process of the invention are those which are substantially free of oxides on their surfaces, and contain heavy metals, and particularly those having molecular weights between 35 and 250.
Compounds containing these metals, and especially their sulfides, halides and manganates, are particularly effective in the process of the invention.
A few metals, such as gold, occur naturally as free metals but most of the metals occur in ores where they are bound in crystalline _30- Jo I
1 structure with other chemical groups or radicals, such as the sulfide, and the like radicals.
As indicated above, while some minerals may not be oleophilic per so, they can be made oleoph fig by use o-f activators or collectors.
examples of ore that can be treated by the process of the invention include, among others, ores con-twining titanium such as illuminate, magnetize and futile; those containing manganese which include psilomelane, pearliest, manganite, rhodochrosite, oligonite; those containing chromium, which include cremate, serpent~nites; those containing nickel, which include pentlandite, chalcopyrite, pyrrhotite, garnierite, nepuite; those containing cobalt, which include lunate, cobaltite, smaltite, heterogeneity; those containing -tungsten include shalt, wolframite; those containing molybdenum include molybdenite, chalcopyrite; those containing vanadium include paternity, vendetta, vanadinite, descloizite, titanomagentite, carnotite; those containing lead and zinc include Golan, sphalerite, chalcopyrite, pyrites castrate; those containing mercury include cinnabar; those containing antimony 1 include stibni-te, quartz; and -those containing bismuth include bismuthinite; those containing aluminum include hydragillite, boehmite; those containing beryllium and lithium include Barlow, spodumene; those containing magnesium include carnality, magnesite and dolomite; those con-twining gold include gold tellurides; those containing silver include Argentine, prostate, pyrargirite; those containing platinum group metals include chromespinellides and hortonolite;
those containing uranium and thorium include urbanite, vendetta, uraninite, Minnesota; those containing tantalum and niobium include tantalize, columbine, pyrochlore-, loparite, microlite; those containing zirconium and rare earths include bade-Lotte, Minnesota, xenotime; and other deposits containing sesame, germanium, thallium, scandium, cadmium, selenium, tellurium, rubidium, gallium, indium, hafnium and rhenium.
The process can also be used to remove minerals such as goat from other solid particles, such as sand, where the purified solid particles are the desired product. In many cases, for example, 1 deposits of construction sand contain contaminate in components, such as coal, which interfere with the use of the sand in formation of concrete as it tends to weaken the structure. In this case, the process of the invention can be used to remove the coal from the sand particles and the product recovered from the aqueous phase is the more desired material. This illustrates the reverse application of the process wherein the desired material may be that remaining in the aqueous phase and the purpose is to remove the material being attracted to the oil phase.
The process of the invention can also be used to advantage in the purification of sludge ponds at industrial sites where the sludge contains undesirable oleophilic products, such as toxins, PUB, and the like, which can be removed by use of the collectors as in the above-described process of the invention.
The process may also be used to remove proteins from mixtures containing proteins and like substances.
The process may also be used in the prepare-1 lion of medicines.
While the process of the invention has been described chiefly in terms of a process for preparing slurries directly in a conditioning drum, the process can also be used for treatment of suspensions or emulsions of oil, tar or hydra-carbon produced from a heavy oil, tar sand or oil shale deposits, by steam injection or by no-lofting or combustion which may contain precious minerals, by utilizing such compositions directly in the process as described above.
To illustrate the process of the invention, the following examples are given. It should be understood, however, that they are given only in the way of illustration and in no way limit the scope of the invention.
EXAMPLE I
This example illustrates the separation of mica flakes from a mixture of mica and silica sand.
A mixture made up of 10 pounds of mica flakes and 90 pounds of silica sand is added to water slurry made up of 30 pounds of water and '7 I
1 25 pounds of heavy oil collector and the mixture tumbled in a rotating tumbler at 100C. After about 10 minutes of tumbling) the mica becomes associated with the heavy oil in the oil phase.
The slurry is then introduced into a water bath which contains an aperture endless belt prepared from vulcanized neoprene arranged as disclosed in the above-described preferred embodiment.
Most of the sand drops through the apertures while most of the heavy oil containing the mica flakes in the oil phase is collected on the neoprene belt. The material that passed through the first flight of the belt passed through the send flight and any Howe oil remaining in the slurry is recovered at the second flight on the neoprene belt. It is found that there is a very high recovery of the mica flakes in the heavy oil and little mica is found in the sand tailings.
EXAMPLE II
This example illustrates the recovery of small amounts of titanium and zirconium from tailings obtained from the hot water process for recovering oil from tar sands which process is ho low ill co~ercial operatioll. The ore being treated contained traces of zirconium and titanium. With suckle a process 8 to 15 percent of the bitumen still remains with the solid ore particles in the tailings.
Tailings from the above process containing 60.0 percent solids, 39.0 percent water and 1.0 percent bitumen was passed through an oleophilic aperture wall surface as show in United States 49236,995. The bitumen collected on the screen was removed and treated to recover the zirconium and titanium. The bit-men collected from these tailings was found to contain more than three times as much zirconium and titanium percentage by weight as compared with the bitumen product of the hot water process.
Another important application of the instant invention relates to the recovery of futile and aunts from the primary and secondary tailings of common-coal hot water extraction mined oil sands plants. The process used in these oil sands plants currently in operation in Fort McMurray, Alberta is based upon the Clark Hot Water Process wherein mined oil sand feed stock is mixed with steam and water in a conditioning tumbler to produce a slurry. Oversize rock, clay lumps and tramp are removed from this slurry at a temperature of approximately 185F
and then the slurry is diluted with hot water and is pumped to a primary swooper-lion vessel when bitumen floats to the top of the vessel and is skimmed off as a primary froth product. Sand, silt, clay, water and bitumen that will not float fall to the bottom of the primary separation vessel and are discarded as primary tailings. A stream of silt, clay and bitumen suspended in water, called the mid-doings stream, is removed from the middle of the primary separation vessel to maintain an effective balance in this vessel. The middlings stream is conveyed to conventional froth flotation vessels where the middlings are aerated to pro-dupe a secondary bitumen froth product, and a secondary tailings stream that is discarded. The primary bitumen froth and the secondary bitumen froth are come '7 brined, mixed Thea a delineate and centrifuged to produce a clean bitumen product for use as upgrading and refining feed stock and a centrifugal tailings stream.
It is known that the centrifugal tailings contain heavy minerals, in particular ores of titanium and of zirconium, and several patents have been granted for the recovery and processing of these minerals, in particular Canadian patents:
861,580 and 879,996 and 927,983 as well as U.S.A. patents 3,656,938 and 3,990,885 and 4,138,467 and 4,150,093.
However, while processing primary and secondary tailings, it has been discovered that these tailings also contain ores of titanium and zirconium in abundance. One important finding of pilot plant studies has been that in par-titular the primary tailings contain approximately 0.3% bitumen which may be used to collect futile, aunts and zircon from these tailings.
The titanium ores that may be recovered from centrifugal tailings generally are high in illuminate and low in futile. In contrast, the titanium ores which may be recovered from primary tailings and from secondary tailings by the instant invention are high in futile and very low in illuminate. On the world market futile is worth approximately 20 times as much per ton as illuminate.
In pilot plant tests, two 45 gallon drums of primary tailings were used as feed stock for the process of the instant invention. This feed stock con-twined 0.3% bitumen, 75.7% solids and 24.0% water by weight and was conveyed to a tumbler containing oleophilic free bodies. The actual free bodies used were 1/2 inch diameter spheres of steel, coated with cadmium, spheres of neoprene mixed with lethargy also 1/2 inch in diameter and 1/4 inch diameter spheres of polyolefin. About equal amounts of each type of sphere were used in the tumbler.
It has been found that shapes other than spheres may be used as is discussed in Canadian patent application 333,832. The tumbler was 18 inches in diameter and 18 inches long and was filled with free bodies, leaving only about 20% free-to board of the drum volume free from oleophilic bodies to permit effective tub-lying and mixing of the free bodies with the feed stock which entered the drum con-tenuously during the test run at approximately 100 pound per hour and which left the drum from the opposite end at the same rate. The free bodies remained in the drum throughout the test. While the feed stock mixed in the drum with the free bodies its dispersed bitumen came or remained in contact with futile, aunts and zircon in the feed stock and then collected into streamers of bitumen that left the drum at the exit end along with water suspended solids as a stream. This stream of bitumen agglomerated tailings next was passed to an aperture Leo-Philip belt separator such as described in Canadian patent application 333,640.
(Similar separators are described in Canadian patent applications 333,641 and 333,830). In this separator the water suspended solids passed through the apertures of the oleophilic belt and the bitumen with the contained futile, aunts and zircon collected on the surface of the oleophilic belt. The belt revolved continuously and the collected bitumen was subsequently removed from the belt surface as a bitumen stream that contained a considerable amount of futile, aunts and zircon as well as other solids such as sand, silt and clay.
The water suspended solids stream analyzed 0.1% bitumen, 69.5% solids and 30.4%
water by weight. The bitumen stream analyzed 38.3% bitumen, 41.7% solids and 20.2% water by weight.
The solids were then removed from the bitumen of the bitumen stream with a solvent that diluted the bitumen and washed the solids and then the solids were dried and analyzed. No illuminate was found in the dried solids but futile content of these solids was approximately 10% along with approximately 0.6% zip-con, and other materials such as aunts, china clay, and quartz.
A magnetic separation test demonstrated that futile could be removed readily from most of the other materials present in these dried solids.
Lyle such additional tests were not conducted, there is no reason that magnetic separation should not be practiced on the solids fraction of the bitumen product while it is still wetted or suspended in the solvent used for washing the bitumen from these solids.
Another method for recovering futile from the bitumen product of the instant invention is to heat the bitumen in an inert atmosphere to vaporize and crack the bitumen to produce an overhead hydrocarbon vapor that is recovered subsequently and leave a residue of coke on the solids particles. Then burning these solids particles with air or oxygen to remove the coke and produce an ash or solids residue that is relatively carbon free and from which the futile may then be extracted magnetically either while the solids are a dry powder or while suspended in water with or without suitable reagents.
Thus the instant invention is of particular advantage for recovering the more expensive titanium ores, such as futile, from the primary and secondary tailings of a hot water oil sands extraction process.
In addition, the process may also be used to recover futile, aunts and zircon from mined oil sands by a similar process. In this case the feed stock for the agglomerating tumbler, containing the oleophilic free bodies, is a slurry of mined oil sand and water that has been prepared previously in a condo-toning tumbler as described above. The process thereafter is similar to the process used for recovering futile from primary tailings described above. The same process may also be used with secondary tailings as feed stock to recover futile from secondary tailings.
Thus the process for recovering futile in the instant invention con-sits of tumbling the feed stock in a tumbler to permit bitumen and futile to become intimately mixed with each other in the presence of water and solids.
Free bodies may be used in the drum but do not have to be used to assist bring-Lo q.31 i' in the bitumen in contact with the futile in the feed stock. The futile in the process becomes part of the bitumen fraction and when the thus prepared feed-stock stream is separated with an aperture oleophilic belt separator the futile and aunts and zircon are part of the bitumen products stream. Thereafter the bitumen stream is separated unto its components and futile is extracted as one of the valuable minerals. Aunts and zircon are additional valuable minerals that are extracted.
Additional test were conducted to determine the need for a drum con-twining oleophilic free bodies in the process to collect futile from the tailings into the bitumen. It was found that without the use of such a drum to treat the tailings before separation by the aperture oleophilic belt the futile content in the bitumen products stream was less than when such a drum was used. The relative amounts were not measured but it appeared that with the drum about I
more futile was produced than without the drum.
From the test work that has been conducted with primary tailings, it has been concluded that the bitumen particles suspended or contained in the prim-cry and secondary tailings of a hot water extraction process are loaded with solids and minerals such as futile and zircon. If this were not so, the bitumen would float and rise to the top of the extraction vessels of the Hot Water Pro-cuss. However, the bitumen that finds its way into the primary and secondary tailings will not float but sinks along with the sand and silt to the bottom of the vessel. When these tailings are then processed with a method that does not rely upon bitumen flotation to achieve the separation, such as with an aperture oleophilic wall separator, the recovered bitumen is high in valuable titanium and zirconium ores such as futile, aunts and zircon.
During the hot water extraction process not all the futile, aunts and zircon become associated with the bitumen but some of these minerals are found in the tailings separate from the bitumen. Therefore, when these tailings are tumbled in a drum in the presence of oleophilic free bodies, this tumbling helps to contact these minerals with bitumen in these tailings to cause these minerals such as futile, aunts and zircon and possibly illuminate to become part of the bitumen phase which is then recovered subsequently in the separation step.
The above specifications refer to futile, aunts and zircon recovery from tailings or sludge of a Hot Water Extraction Process plant. However, the instant invention has application as well in the recovery of these valuable minerals directly from a prepared slurry of mined oil sand without passing this slurry first through the primary and/or secondary extraction vessels of the Hot Water Process. or this aspect of the instant invention, a slurry of mined oil sand and water and/or steam is prepared which is then passed directly through the the tumbler with oleophilic free bodies and then through the aperture oleophilic sieve separation apparatus for recovery of the bitumen and for recovery of the valuable minerals such as futile, aunts and zircon directly with the bitumen, and then the separation of these valuable minerals from the bitumen and the sepal ration of the titanium minerals therefrom by magnetic separation as described above. Alternately the slurry may be separated without the use of a tumbler con-twining oleophilic free bodies. In that case the prepared slurry is passed dip neatly to the aperture oleophilic wall for separation, bitumen recovery and titanium minerals recovery as described above.
Claims (41)
1. A process for recovering minerals from mixtures containing the mineral particles and other particulate solid particles which comprises (1) insuring that the mineral particles in the mixture have an oleophilic surface and such surface is sufficiently large to be attracted to other oleophilic surfaces, (2) passing the mixture containing the mineral particles and the other particulate solid particles through an apertured surface which is oleophilic so that the mineral particles are attracted to the said oleophilic apertured surface and the other parti-culate solid particles pass through the apertures, and (3) removing the mineral particles from the apertured surface.
2. A process as in Claim 1 wherein the apertured surface is coated with an oleophilic oily material which captures the oleophilic mineral particles.
3. A process as in Claim 1 wherein the apertured surface is coated with an oleophilic material which captures the oleophilic mineral particles, and the oleophilic material containing the mineral particles is removed from the apertured surface and the surface again coated with oleo-philic material.
4. A process as in Claim 1 wherein the mineral particles and the particulate solid particles are first mixed with an aqueous solution containing an oleophilic material such that the oleophilic surfaces of the mineral particles become coated with a thick coating of the said oleophilic material and the particulate solid particles become coated with water, and then passing the mixture through the oleophilic apertured surface.
5. A process as in Claim 3 or 4 wherein the oleophilic material is an oleophilic bitumen.
6. A process as in Claim 3 and in Claim 4 wherein the oleophilic material is a grease.
7. A process as in Claim 4 wherein the components in the aqueous solution are tumbled in a drum to effect a thorough coating of the mineral particles with the oleophilic material and the particulate solid particle with water.
8. A process as in Claim 1 wherein the mixture of mineral particles and other particulate solid particles is mixed with an emulsion of an oleophilic hydrocarbonaceous material and water wherein the hydrocarbonaceous material is the dis-persed phase and the water is the continuous phase, to effect a thorough mixing of the components and then an emulsion breaker is added so that the hydro-carbonaceous material is free to find the oleophilic surfaces of the mineral particles and become attached thereto, and the combined mixture is then passed through the oleophilic apertured surface.
9. A process as in Claim 8 wherein the emulsion is an emulsion of bitumen and water.
10. A process for recovering minerals from low grade ore mixtures containing the mineral particles, other particulate solid particles and an oleophilic material which comprises (1) forming an aqueous slurry of the above mixture wherein the mineral particles are or become attached to the oleophilic material and the other particulate solid particles become attached to the water, and then bringing the mixture into contact with an apertured wall having an oleophilic surface wherein the oleophilic material containing the mineral particles is attracted to and attached to the oleophilic surface of the apertured wall and the water phase containing the other particulate solid particles passes through the apertures in the wall, recovering the oleophilic material containing the mineral particles from the aper-tured wall and treating the said material to recover the mineral particles.
11. A process as in Claims 3, 4 or 10 wherein the oleophilic material present in the mixture of mineral particles and other particu-late solid particles is bitumen having a viscosity between 0.1 to 10,000 poises.
12. A process as in Claims 3, 4 or 10 wherein the apertured wall is a moving mesh belt at least partly submerged in water.
13. A process as in Claims 3, 4 or 10 wherein the apertures of the said wall have dimensions within the range of 0.01 to 0.05 inches.
14. A process as in Claims 3, 4 or 10 wherein the mineral particles to be recovered is a mineral of a heavy metal which is substantially non oxidized and the particulate solids is a hydrophilic silicate.
15. A process as in Claims 3, 4 or 10 wherein the mineral to be recovered is of the group of precious and semi-precious metals including rhodium, platinum, gold, silver and tin.
16. A process as in Claims 3, 4 or 10 wherein the mineral to be recovered is of the group including titanium and zirconium.
17. A process as in Claims 3, 4 or 10 wherein the mineral to be recovered is a radio-active material such as radium or uranium ore.
18. A process as in Claims 3, 4 or 10 wherein the oil phase containing the mineral and oleophilic material is removed from the wall by forcing the said phase with a transfer roller, into and through the apertures, removing said phase from the aperture wall and out of the apertures onto the surface of a recovery roller, and removing the oil phase from the surface of the recovery roller by recovery means for further treatment.
19. A process as in Claims 3, 4 or 10 wherein the oil phase containing the mineral and oleophilic material recovered from the wall is subjected to a solvent extraction treatment to recover the mineral particles.
20. A process as in Claims 3, 4 or 10 wherein the oil phase containing the mineral and oleophilic material recovered from the wall is subjected to a thermal treatment to recover the mineral particles.
21. A process as in Claims 3, 4 or 10 wherein the apertured wall is in the form of a mesh apertured belt coated with an artificial rubber.
22. A process as in Claims 3, 4 or 10 wherein the apertured wall is in the form of a drum.
23. A process as in Claims 3, 4 or 10 wherein the slurry particles too large to pass through the apertures of the wall are removed from the slurry prior to bringing the slurry into contact with the apertured wall.
24. A process as in Claims 3, 4 or 10 wherein the ore containing the mineral particles and particulate solid particles is crushed to a size between 0.01 to 0.5 inches before being introduced into the slurry.
25. A process as in Claims 3, 4 or 10 wherein the slurry is tumbled and rotated in a rotary tumbler for a period of 1 to 25 minutes before the slurry is placed in contact with the apertured wall.
26. A process for recovering a mineral from crushed solid ore containing the desired mineral and particulate solids particles termed gangue which comprises the steps of:
a. mixing the crushed solids con-taining the mineral and gangue with water, steam and an oleophilic material that selectively attracts the mineral into an oil phase to the exclusion of the gangue which is retained in an aqueous phase, in a rotating conditioning drum to form a slurry, b. introducing the slurry into a water bath containing an at least partly submerged moving apertured endless belt separator having one or more oleophilic surfaces.
c. directing the slurry in the water bath into contact with the submerged moving belt at a temperature such that the oil phase containing the mineral and oleophilic material has a viscosity in the range of 0.1 to 10,000 poises wherein the oil phase contacts the oleophilic sur-face of the belt and adheres thereto and the aqueous phase containing the gangue passes through the apertures, d. recovering the adhering oil phase from the aperture belt surface, e. removing the oil phase and recovering the desired mineral from the oil phase so removed.
a. mixing the crushed solids con-taining the mineral and gangue with water, steam and an oleophilic material that selectively attracts the mineral into an oil phase to the exclusion of the gangue which is retained in an aqueous phase, in a rotating conditioning drum to form a slurry, b. introducing the slurry into a water bath containing an at least partly submerged moving apertured endless belt separator having one or more oleophilic surfaces.
c. directing the slurry in the water bath into contact with the submerged moving belt at a temperature such that the oil phase containing the mineral and oleophilic material has a viscosity in the range of 0.1 to 10,000 poises wherein the oil phase contacts the oleophilic sur-face of the belt and adheres thereto and the aqueous phase containing the gangue passes through the apertures, d. recovering the adhering oil phase from the aperture belt surface, e. removing the oil phase and recovering the desired mineral from the oil phase so removed.
27. A process as in Claim 26 wherein the ore to be treated is tar sand containing a mineral component and the oleophilic material used in the process is the bitumen naturally occurring within the tar sand.
28. A process as in Claim 26 wherein the oleophilic material is a heavy oil.
29. A process as in Claim 26 wherein the oleophilic material is an ionic compound having a long chain hydrocarbon group of at least 10 carbon atoms.
30. A process as in Claim 26 wherein the gangue is a silicate sand.
31. A process as in Claim 26 wherein the mineral is an ore of silver or of gold.
32. A process as in Claim 26 wherein the mineral to be recovered is an ore of a heavy metal having a molecular weight between 35 and 250.
33. A process as in Claim 26 wherein the mineral is recovered from the oil phase removed from the belt by thermal treatment wherein the oleophilic material is vaporized off and the mineral recovered as residue.
34. A method for recovering titanium minerals from tailings of a hot water extraction process for mined oil sands, comprising the following steps:
a) passing said tailings through an apertured oleophilic surface which permits sand, silt, clay and other minerals and water to pass through the apertures but which causes bitumen, zircon, titanium minerals and other minerals to adhere to said wall, b) removing said adhering bitumen, zircon, titanium minerals and other minerals from said wall, c) separating said bitumen from said zircon, titanium minerals and other minerals removed from said wall, d) magnetically separating said titanium minerals from said zircon and from said other minerals removed from said wall.
a) passing said tailings through an apertured oleophilic surface which permits sand, silt, clay and other minerals and water to pass through the apertures but which causes bitumen, zircon, titanium minerals and other minerals to adhere to said wall, b) removing said adhering bitumen, zircon, titanium minerals and other minerals from said wall, c) separating said bitumen from said zircon, titanium minerals and other minerals removed from said wall, d) magnetically separating said titanium minerals from said zircon and from said other minerals removed from said wall.
35. A method as in Claim 34 wherein said titanium minerals are composed largely of rutile.
36. A method as in claim 34 wherein said tailings are first tumbled in a drum for the purpose of causing the bitumen present in the tailings to agglomerate with the titanium minerals, or to collect the titanium minerals within said bitumen, befoe passing said tailings through an apertured oleophilic surface.
37. A method as in claim 36 wherein said drum contains oleophilic surfaced spheres or other shape free bodies that tumble in said drum for the purpose of aiding said bitumen to agglomerate with or collect said titanium minerals before separation of the tailings by said apertured oleophilic wall.
38. A method as in claim 34 wherein said tailings are primary tailings produced from a primary separation vessel.
39. A method as in claim 34 wherein said tailings are secondary tailings produced from a middlings separation vessel.
40. A method as in claim 34 wherein said tailings are a slurry of mined oil sand and water produced by a conditioning tumbler as in the Hot Water Process, but without prior separa-tion in a separation vessel.
41. A process for recovering minerals from mixtures con-taining mineral particles and other particulate solid particles, the mineral particles having an oleophilic surface sufficiently large to be attracted to other oleophilic surfaces, comprising contacting the mixture containing the mineral particles and the other particulate solid particles with a solid, uncoated oleo-philic surface so that the mineral particles are selectively attracted to the oleophilic surface while the other particles are not, and removing the mineral particles from the oleophilic sur-face.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US28317981A | 1981-07-14 | 1981-07-14 | |
| US283,179 | 1981-07-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1241297A true CA1241297A (en) | 1988-08-30 |
Family
ID=23084889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000407183A Expired CA1241297A (en) | 1981-07-14 | 1982-07-13 | Oleophillic adhesion type separation of minerals using a moving apertured collection barrier |
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| Country | Link |
|---|---|
| CA (1) | CA1241297A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7341658B2 (en) | 2002-04-18 | 2008-03-11 | Tatanium Corporation Inc. | Recovery of heavy minerals from a tar sand |
| US7708146B2 (en) | 2007-11-14 | 2010-05-04 | Jan Kruyer | Hydrocyclone and associated methods |
-
1982
- 1982-07-13 CA CA000407183A patent/CA1241297A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7341658B2 (en) | 2002-04-18 | 2008-03-11 | Tatanium Corporation Inc. | Recovery of heavy minerals from a tar sand |
| US7708146B2 (en) | 2007-11-14 | 2010-05-04 | Jan Kruyer | Hydrocyclone and associated methods |
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