Source: https://patents.justia.com/patent/10245597
Timestamp: 2019-08-21 20:15:01
Document Index: 134886212

Matched Legal Cases: ['Application No. 61', 'Application No. 61', 'application No. 61', 'application No. 61', 'application No. 61', 'application no. 61']

US Patent for Dimensionally controlled ‘engineered polymer bubble’ for flotation separation Patent (Patent # 10,245,597 issued April 2, 2019) - Justia Patents Search
Justia Patents Effecting FlotationUS Patent for Dimensionally controlled ‘engineered polymer bubble’ for flotation separation Patent (Patent # 10,245,597)
Apr 1, 2013 - CiDRA Corporate Services Inc.
Apparatus is provided featuring a first and second cells. The first cell receives an ore slurry having mineral particles of interest, receives unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, causes the unexpanded polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area, and provides an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest. The second cell receives the expanded polymer microsphere foam layer, and causes the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest. The second cell may also provide a mineral concentrate output having the mineral particles of interest.
The present application corresponds to international application no. PCT/US2013/034762, filed 1 Apr. 2013, which claims the benefit of U.S. Provisional Patent Application No. 61/618,046 (CCS-0083//712-2.379), filed 30 Mar. 2012, as well as U.S. Provisional Patent Application No. 61/650,185 (CCS-0085//712-2.388), filed 22 May 2012, which are both hereby incorporated by reference herein in their entirety.
International application no. PCT/US2013/034762 is a continuation-in-part (CIP) of, and claims benefit to, Patent Cooperation Treaty (PCT) application Ser. No. PCT/US12/39591 (712-2.383), filed 25 May 2012, entitled “Method and system for releasing mineral from synthetic bubbles and beads,” which is also incorporated by reference herein in its entirety.
The present application is also related to eight (8) PCT applications, which were all concurrently filed on 25 May 2012, and which are all incorporated by reference in their entirety, as follows:
PCT application no. PCT/US12/39528, entitled “Flotation separation using lightweight synthetic bubbles and beads:”
PCT application no. PCT/US12/39534, entitled “Mineral separation using functionalized polymer membranes:”
PCT application no. PCT/US12/39540, entitled “Mineral separation using sized, weighted and magnetized beads:”
PCT application no. PCT/US12/39596, entitled “Synthetic bubbles and beads having hydrophobic surface;”
PCT application no. PCT/US12/39631, entitled “Mineral separation using functionalized filters and members;”
Moreover, the present application is also related to PCT application no. PCT/US12/69402, filed 13 Dec. 2012, entitled “Mineral separation using functionalized polymer-coated filters and membranes,” which is hereby incorporated by reference in its entirety.
The present application is also related to provisional application No. 61/604,088, filed 28 Feb. 2012, entitled “Mineral separation using functionalized polymer-coated filters and membranes,” which is hereby incorporated by reference in its entirety.
The present application is also related to provisional application No. 61/604,088, filed 22 May 2012, entitled “Charged engineered polymers for flotation separation,” which is hereby incorporated by reference in its entirety.
The present application is also related to provisional application No. 61/604,088, filed 13 Jun. 2012, entitled “Bubble size determination based on bubble stiffness,” which is hereby incorporated by reference in its entirety.
The present application is also related to provisional application no. 61/755,297, filed 22 Jan. 2013, entitled “Method of enhanced separation of oil sands ore constituents,” which is hereby incorporated by reference in its entirety.
By way of example, in the case of minerals separation the mineral bearing ore may be crushed and ground to a size, typically around 100 microns, such that a high degree of liberation occurs between the ore minerals and the gangue (waste) material. In the case of copper mineral extraction as an example, the ground ore is then wet, suspended in a slurry, or ‘pulp’, and mixed with reagents such as xanthates or other reagents, which render the copper sulfide particles hydrophobic.
In standard flotation separation, air is constantly forced through the pulp slurry to create a certain ‘flux’ of air passing through the pulp. This process, while now used widely, and refined over many decades of use, has limitations:
Due to the natural dynamics of the bubbles, a mineral-bearing particle may not typically be carried to the surface on one bubble, but may have to attach to several bubbles to reach the froth layer.
The assignee of the present patent application has previously disclosed the use of polymer shells (aka “engineered bubbles”) and polymer plates as a mineral separation method, consistent with that set forth in the patent applications above. In these approaches, a polymer material is modified with an appropriate mineral collector chemistry to make the surface of the polymer attractive to the mineral of interest. In the process, minerals attach to the polymer—in the case of the shells, separation is achieved via flotation, whereas in the case of plates, it is envisioned that the bound mineral can be washed off (with the release being chemically triggered—e.g., pH for example), or mechanically released (e.g., vibration/ultrasonically for example).
Expandable polymer shells are widely used in a range of commercial products such as adhesives and sealants for example. One such example is the Dualite brand from a company named, Henkel Corp. In this case, polymer shells made of a thermoset polymer can be expanded at a particular temperature trigger point. The expansion forces come from a ‘blowing agent’—a low boiling point liquid. At the point of the liquid—vapor transition temperature, the pressure inside the microsphere increases and the sphere is ‘blown up’. Spheres can increase their size by 50 fold in volume. Their use in sealants and adhesives provides a very low density filler/foam-type expansion material.
For example, a new approach to help solve this problem may be through the use of the expandable polymer shell technology. This expandable polymer shell technology may be adapted for other uses, such as for flotation separation consistent with that set forth herein.
The present application discloses additional improvements/alternatives to the concept for minerals separation set forth in the aforementioned PCT application.
The aforementioned type of polymer microsphere expansion may be of interest in the field of mineral separation, as the dimensional changes in the microspheres can be used for attachment and de-attachment of the recovered minerals.
Consistent with the concepts set forth herein for the optimization of flotation using engineered bubbles or beads, including engineered polymers such as polymer “bubbles” or “beads,” this overall approach has several distinct advantages, one of which is that by floating the polymer bubbles up through a solution (such as an ore slurry) having the mineral particles of interest, e.g., chalcopyrite (or copper particles), the probability of an impact and attachment can be very high. The following sets forth new techniques for collection and release of mineral particles in relation to such a solution:
Consistent with that disclosed herein, two approaches to using polymer based bubbles to capture the mineral particles of interest, such as chalcopyrite, may include imbedding the polymer bubbles with a collector material which attracts, e.g., copper, or second, may include having the polymer bubbles embedded with a hydrophobic material that would attract the standard collectors that are currently available and used today. (For example, assuming that the standard collectors are based on the process of, e.g., a copper collector which is attracted to copper but also with a hydrophobic tail.)
One important aspect of the process that must be optimized regardless of the method used, is that the polymer bubbles must attract and attach to the mineral particles of interest, such as chalcopyrite, during the collection phase of the process and release the mineral particles of interest once that phase is complete. This can be a very difficult task since essentially the bubbles must exhibit a strong attraction to hold, e.g., the chalcopyrite. but not too strong to allow release of the material after the collection. The additional improvements/alternatives to the concept for minerals separation provides further solutions that address the needs of this difficult task.
Pressurized Release for Collapsing Polymer Bubbles (CCS-0083)
According to some embodiments, the present invention may take the form of apparatus featuring a first cell and a second cell.
The first cell may be configured to receive an ore slurry having mineral particles of interest, to receive unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, to cause the unexpanded polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area, and to provide an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest.
The second cell may be configured to receive the expanded polymer microsphere foam layer, and to cause the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest.
The second cell may also be configured to provide a mineral concentrate output having the mineral particles of interest.
In operation, and by way of example, the expandable polymer microspheres which have been modified with mineral collector chemistries may be injected into a flotation cell along with a mineral ore pulp. Agitation may be induced (as is used in the known air-based flotation system) to mix the mineral ore pulp and the expandable polymer microspheres. A trigger temperature of a blowing agent encapsulated in the expandable polymer microsphere may be set at below the temperature of the pulp/water mixture in the flotation vessel. (This may require cool or chilled storage of the unexpanded polymer microspheres prior to their induction to the flotation cell.) The polymer microsphere expand, become buoyant, and create an increased bubble flux in the mineral ore pulp, presenting surface area for mineral bearing particles to attach to and be lifted to the surface.
An agglomerated mass of expanded polymer microspheres on the surface is functionally equivalent to the froth layer on the surface of a conventional flotation cell, and is skimmed and moved to a release stage. Here, the expanded polymer microspheres are passed to a release tank in a batch process: the tank may be filled with the mineral rich foam, and the tank, e.g., either pressurized to a nominally elevated level, or chilled, such that the blowing agent reverses through a transition phase (returning to a liquid phase or a low pressure phase). This transition causes the expanded polymer microspheres to collapse, and the dramatic or substantial reduction in sphere surface area will result in a mechanical shearing off of the attached minerals. The mineral particles may separate from the collapsed polymer microspheres due to gravitation separation—e.g., the mineral particles of interest sink in the tank, whereas the unexpanded polymer microspheres remains nominally buoyant and float.
Alternatively, according to some embodiments of the present invention, the flotation cell may be configured so that the expanded polymer microsphere foam layer on the surface may be allowed to spill over and be received by a spillover container, then provided for further processing, including being provided to release apparatus.
As this type of process to release the minerals could be done quickly in a batch-step process, the throughput of the cell is not typically compromised.
According to some embodiments, the present invention may also take the form of a method including the steps of:
In a first cell, receiving an ore slurry having mineral particles of interest, receiving unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, causing the unexpanded polymer microspheres to expand substantially in volume into expanded microspheres having a substantially increased sphere surface area, and providing an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest.
In a second cell, receiving the expanded polymer microsphere foam layer, and causing the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest. The method may also include providing from the second cell a mineral concentrate output having the attached mineral particles of interest.
The scope of the invention is also intended to include, or take the form of, apparatus comprising means for receiving an ore slurry having mineral particles of interest, receiving unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, causing the unexpanded polymer microspheres to expand substantially in volume into expanded microspheres having a substantially increased sphere surface area, and providing an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest; in combination with means for receiving the expanded polymer microsphere foam layer, and causing the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest. The means for receiving the expanded polymer microsphere foam layer may also include means for providing a mineral concentrate output having the attached mineral particles of interest.
Condensation Release for Collapsing Polymer Bubbles (CCS-0085)
Alternatively, according to some embodiments of the present invention, the releasing apparatus may be configured as a condensing tank for lowering the temperature of the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest.
According to some embodiments, the present invention may take the form of a method featuring steps for
receiving in a processor a plurality of synthetic beads in the form of polymer microspheres carrying mineral particles, each of the polymer microspheres comprising a surface and a plurality of molecules attached to the surface, the molecules comprising a functional group having a chemical bond for attracting or attaching one or more of the mineral particles to the molecules, causing the mineral particles to attach to the polymer microspheres; and
interrupting the chemical bond of the functional group so as to remove the mineral particles from the polymer microspheres.
The polymer microsphere may include, or take the form of, the expandable polymer microspheres set forth herein. The interruption of the chemical bond of the functional group so as to remove the mineral particles from the expandable polymer microspheres may include, or take the form of, pressurizing or cooling the expandable polymer microspheres to collapse the same.
The present invention may be used alone, or in conjunction with that set forth in the aforementioned PCT application Ser. No. PCT/US12/39591 (712-2.383) consistent with that summarized below:
According to some embodiments, the present invention may take the form of an apparatus featuring a processor configured to receive a plurality of synthetic beads in the form of polymer microspheres carrying mineral particles, each of the polymer microspheres comprising a surface and a plurality of molecules attached to the surface, the molecules comprising a functional group having a chemical bond for attracting or attaching one or more of the mineral particles to the molecules, causing the mineral particles to attach to polymer microspheres; and releasing apparatus configured to interrupt the chemical bond of the functional group so as to remove the mineral particles from the polymer microspheres.
According to some embodiments of the present invention, the processor may be configured to cause the polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area. By way of example, the polymer microspheres may be caused to expand by an increase in temperature, including where the temperature of the ore slurry is greater than the temperature of the polymer microspheres. The polymer microspheres may be caused to expand by using other techniques consistent with that set forth herein.
According to some embodiments of the present invention, the processor may be configured as a higher temperature flotation cell or tank, e.g., to receive unexpanded polymer microspheres and to cause the unexpanded polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area.
According to some embodiments of the present invention, the releasing apparatus may be configured to cause the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres that results in the mechanical shearing off of the attached mineral particles of interest.
According to some embodiments of the present invention, the processor may be configured to maintain the ore slurry at a predetermined temperature, and the unexpanded polymer microspheres may be configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand substantially in volume into the expanded polymer microspheres having the substantially increased sphere surface area when received in the processor.
According to some embodiments of the present invention, the releasing apparatus may be configured as a re-pressurization cell, or a condensing tank, or a lower temperature separation tank, or a release tank.
According to some embodiments of the present invention, the releasing apparatus may be configured to be filled with an expanded polymer microsphere foam layer or mineral rich foam, and to be pressurized to a nominally elevated level, or chilled to a lower temperature, such that the blowing agent reverses through a transition phase, including either returning from a gas phase to a liquid phase or returning from a high pressure phase to a low pressure phase.
Apparatus in the Form of a Cell or Column
The separation process may be implemented using density-based separation, where the synthetic bubbles or beads may be configured to be separated from the mixture based at least partly on the difference between the density of the enriched synthetic bubbles or beads having the valuable material attached thereto and the density of the mixture, consistent with that disclosed in PCT patent application serial no. PCT/US12/39528 (WFVA/CiDRA file no. 712-2.356-1/CCS-0052), filed 25 May 2012, which is hereby incorporated by reference in its entirety.
FIG. 17a illustrates apparatus according to some embodiments of the present invention, in the form of an arrangement of a flotation cell for a minerals recovery process.
FIG. 17b illustrates apparatus according to some embodiments of the present invention, in the form of a combined flotation cell and re-pressurization cell for mineral release from an expanded polymer foam.
FIG. 17c illustrates a re-pressurization release concept, which may form part of some embodiments of the present invention.
FIG. 18a illustrates an expanded polymer bubble having chalcopyrite attached thereto, according to, or forming part of, some embodiments of the present invention.
FIG. 18b illustrates a collapsed expanded polymer bubble having the chalcopyrite detached, according to, or forming part of, some embodiments of the present invention.
FIG. 18c illustrates apparatus according to some embodiments of the present invention, including where the expanded polymer bubble in FIG. 18a having chalcopyrite attached thereto overflow a flotation cell or tank and are provided to a condensation cell or tank to be collapsed into the collapsed expanded polymer bubble in FIG. 18b.
FIGS. 17a to 17c (CCS-0083)
By way of example, and according to some embodiments of the present invention, FIGS. 17a to 17c show apparatus generally indicated as 1000 featuring a first cell 1002 (e.g., a flotation cell or tank) in combination with a second cell 1004 (e.g., a release, re-pressurization or condensing cell).
The first cell 1002 may be configured to receive an ore slurry 1006 having mineral particles of interest, to receive unexpanded polymer microspheres 1008 comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, to cause the unexpanded polymer microspheres 1008 to expand substantially in volume into expanded polymer microspheres 1010 having a substantially increased sphere surface area, and to provide an expanded polymer microsphere foam layer 1012 comprising the expanded polymer microspheres 1010 with attached mineral particles of interest.
The second cell 1004 may be configured to receive the expanded polymer microsphere foam layer 1012, to cause the expanded polymer microspheres 1010 to collapse substantially in volume into collapsed polymer microspheres 1014 having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles 1016 of interest, and to provide a mineral concentrate output 1018 having the mineral particles 1016 of interest.
The first cell 1002 may be, or take the form of, a flotation cell or tank, e.g., that is known in the art, including those that form part of known mineral separation processes. However, the scope of the invention is not intended to be limited to any particular type or kind of first cell or tank, and may include first cells or tanks that are now known or later developed in the future.
By way of example, the first cell 1002 may include an agitator 1018 configured to cause or induce agitation to mix the ore slurry 1006 and polymer microspheres like elements 1008 and/or 1010. Agitators are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.
In the embodiment shown in FIGS. 17a to 17c, the first cell 1002 is configured to receive unexpanded polymer microspheres 1008 that are expanded by a change in temperature, e.g., caused by a higher temperature of the ore slurry 1006. However, the scope of the invention is intended to include the first cell 1002 receiving previously expanded polymer microspheres that have a lower density than the ore slurry, are buoyant and rise and float upwardly in the first cell 1002. In this embodiment, the expanded polymer microspheres in the expanded microsphere foam layer 1012 are similarly collapsed to cause the mechanical shearing off of the attached mineral particles 1016 of interest. The scope of the invention is not intended to be limited to the degree of expansion (e.g., no expansion, partially expanded, or fully expanded) of the polymer microspheres received in the flotation cell 1002.
The unexpanded polymer microspheres 1008 may be configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres 1008 to expand substantially in volume into the expanded polymer microspheres 1010 having the substantially increased sphere surface area when received in the first cell 1002. The blowing agent may be encapsulated, e.g., in an interior part (see FIG. 4b, element 86 below). By way of example, the blowing agent may include either a liquid that responds to a change in temperature and transforms into a gas, or a gas that responds to a change in temperature and transforms from a low pressure phase into a high pressure phase. The scope of the invention is not intended to be limited to the type or kind of gas or liquid used as the blowing agent, and is intended to includes gases and liquids both now known and later developed in the future. Embodiments are also envisioned, and the scope of the invention is intended to include, the blowing agent taking the form of an expandable solid or semi-solid (e.g. gel) either now known and later developed in the future, e.g., that once expanded, cause the polymer microspheres 1010 to have a lower density than the ore slurry, be buoyant and rise and float upwardly in the first cell 1002. In particular, the first cell 1002 may be configured to maintain the ore slurry 1006 at a predetermined temperature, and the unexpanded polymer microspheres 1008 may be configured with the blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres 1008 to expand substantially in volume into the expanded polymer microspheres having the substantially increased sphere surface area when received in the first cell 1002. According to some embodiments of the present invention, the unexpanded polymer microspheres 1008 may be cooled or chilled to a temperature below the predetermined temperature prior to induction to the first cell 1002.
The expanded polymer microspheres 1010 may be configured to become buoyant and create an increased bubble flux in the ore slurry 1006, presenting surface area for mineral bearing particles to attach to and be lifted to the surface and form the expanded polymer microsphere foam layer 1012. In particular, the expanded polymer microsphere foam layer 1012 may take the form of an agglomerated mass of expanded spheres on the surface to be skimmed and moved to the second cell 104, including a release stage, or provided as foam overflow 1012a as shown in FIG. 17b. Alternatively, the expanded polymer microsphere foam layer 1012 may spill over the first cell or tank 1002, collected in a spillover tank 1013 (FIG. 18c) and provided to the second tank 1004, consistent with that disclosed in relation to FIGS. 18a to 18c.
The second cell 1004 may include a re-pressurization cell or tank, or a condensing tank or cell, or a release tank. Cell or tanks for pressurizing or condensing its contents are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future. Moreover, a person skilled in the art would be able to configured the second cell or tank 1004 to cause, e.g., the expanded polymer microspheres 1010 to collapse substantially in volume into the collapsed polymer microspheres 1014 having the substantially reduced sphere surface area that results in the mechanical shearing off of the attached mineral particles 1016 of interest without undue experimentation based at least partly on that disclosed herein. By way of example, the second cell 1004 may be configured to be filled with the expanded polymer microsphere foam layer 1012 or mineral rich foam, and to be pressurized to a nominally elevated level, or chilled to a lower temperature (e.g. to cause condensing), such that the blowing agent reverses through a transition phase, including either returning from a gas phase to a liquid phase or returning from a high pressure phase to a low pressure phase.
By way of example, and according to some embodiments of the present invention, the mineral particles 1016 of interest may separate from the collapsed polymer microspheres 1014 due to gravitation separation, including where minerals sink in the second cell 1004 and where the unexpanded or collapsed polymer microspheres generally indicated by arrow labeled 1008′ (e.g., with or without some attached mineral of interest) tend to remain nominally buoyant and may float to the top surface, e.g., as shown in FIG. 18c.
By way of example, and according to some embodiments of the present invention, the second cell 1004 may also be configured to provide the mineral concentrate output 1018 having the mineral particles 1016 of interest, e.g., for further processing, including by processing either now known or later developed in the future. The scope of the invention is not intended to be limited to either how the second cell 1004 may be configured to provide the mineral concentrate output 1018, or how the mineral concentrate output 1018 is further processed once provided from the second cell 1004.
By way of example, and according to some embodiments of the present invention, the second cell 1004 may also be configured to provide a discarded foam output 1020 having the collapsed polymer microspheres, e.g., for further processing, including discarding, cleaning and recirculation, or for or by some other processing either now known or later developed in the future. The scope of the invention is not intended to be limited to either how the second cell 1004 may be configured to provide the discarded foam output 1020, or how the discarded foam output 1020 is further processed once discarded from the second cell 1004.
By way of example, and according to some embodiments of the present invention, and consistent with that set forth herein, the molecules may include a functional group having a chemical bond for attaching the mineral particles of interest, e.g., consistent with that disclosed herein. The scope of the invention is not intended to be limited to any particular type or kind of molecule, functional group, or chemical bond for attaching the mineral particles of interest to the polymer microspheres that may be used to implement the present invention, and is intended to include molecules, functional groups, or chemical bonds that are now known and later developed in the future.
By way of example, and according to some embodiments of the present invention, the volume of the expanded polymer microspheres 1010 may be about 50 times the volume of the unexpanded polymer microspheres 1008. However, scope of the invention is not intended to be limited to any particular volumetric expansion or contraction between the unexpanded polymer microspheres 1008 and the expanded polymer microspheres 1010, and is intended to include volumetric expansions or contractions less than or greater than 50.
The second cell or tank 1004 may be configured with flow/pressure valves 1022 configured for controlling the flow of the foam overflow 1012a from the first cell 1002 to the second cell 1004, the mineral concentrate output 1018 from the second cell 1004, and the discard foam output 1020 from the second cell 1004. Such flow/pressure valves 1022 are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof.
FIGS. 18a to 18c (CCS-0085)
FIGS. 18a to 18c show an alternative approach that builds on the basic idea that the bubbles may be expanded during the collection phase where the larger surface area would be able to collect the mineral of interest, e.g., chalcopyrite, and fill the outer surface. After collection, the mineral of interest, e.g., chalcopyrite, may be removed from the polymer bubble. For example, the bubble may be collapsed or shrunk and the chalcopyrite particles of interest would be forced or mechanically sheared off. FIGS. 18a and 18b shows the two states of the polymer bubble, including an expanded stated in FIG. 18a and a collapsed state in FIG. 18b.
Consistent with that set forth herein a variety of conditions could be used to cause the polymer bubble to expand. Temperature is a typical parameter used to control the two-state bubble as demonstrated with Henkel's polymer microsphere offering, consistent with that shown in FIG. 18c where a higher temperature flotation tank 1002 is shown with expanded polymer bubbles 1010. Other options may include or be pH, illumination with optical wavelengths or microwave. The scope of the invention is not intended to be limited to any particular way to expand the polymer bubbles, and is intended to include techniques now and later developed in the future.
FIG. 18c shows a technique where temperature may be used to collapse the polymer bubbles and release the chalcopyrite attached thereto. As shown, the polymer bubbles would be activated by the higher temperature bath of chalcopyrite which would cause the bubble to expand and attach to the material or mineral particle of interest. The bubbles would float the material to the top of the floatation tank 1002 where it would, e.g., spill over as an expanded microsphere foam layer 1012, be collected in the spillover container 1013 and sent to a second tank, e.g., a lower temperature condensing tank 1004′. Here, the bubbles and chalcopyrite may be cooled so that the bubbles would collapse and shed the chalcopyrite particles 1016 of interest. The chalcopyrite could then be collected from the bottom of the second tank 1004′.
Condensing tanks like element 1004′ and spillover tanks like element 1013 are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.
Embodiments are also envisioned, and the scope of the invention is intended to include, the pressure release technique disclosed in relation to FIGS. 17a-17c being used in combination with the cooling release technique disclosed in relation to FIGS. 18a-18c, for collapsing the polymer bubbles and releasing chalcopyrite particles.
FIGS. 1 to 16c of PCT application Ser. No. PCT/US12/39591
Moreover, embodiments are envisioned in which the present invention shown and described in relation to FIGS. 17a to 17c and 18a to 18c may be used alone, or in conjunction with that set forth in the aforementioned PCT application Ser. No. PCT/US12/39591 consistent with that disclosed in relation to FIGS. 1 to 16b below:
In physisorption, the valuable minerals are reversibly associated with the synthetic bubbles or beads, attaching due to electrostatic attraction or van der Waals bonding. The physisorbed mineral particles can be desorbed or released from the surface of the synthetic bubbles or beads if the pH value of the solution changes.
Furthermore, the surface chemistry of the most minerals is affected by the pH. Some minerals develop a positive surface charge under acidic conditions and a negative charge under alkaline conditions. The effect of pH changes is generally dependent on the collector and the mineral collected. For example, chalcopyrite becomes desorbed at a higher pH value than galena, and galena becomes desorbed at a higher pH value than pyrite. If the valuable mineral is collected at a pH of 8 to 11, it is possible to weaken the bonding between the valuable mineral and the surface of the polymer bubbles or beads by lower the pH to 7 and lower. However, an acidic solution having a pH value of 5 or lower would be more effective in releasing the valuable mineral from the enriched polymer bubbles or beads. According to one embodiment of the present invention, the bead recovery process or processor 50 as shown in FIG. 1 can be adapted for removing the mineral particles in the enriched polymer bubbles 18 by changing the pH of the solution in the flotation column 54. For example, as the reclaimed water from piping 64 is used to wash the enriched polymer bubbles 18 inside the flotation column 54, it is possible to use a container 168 to release an acid or acidic solution 170 into the reclaimed water as shown in FIG. 8. There are a number of acids easily available for changing the pH. For example, sulfuric acid (HCl), hydrochloric acid (H2SO4), nitric acid (HNO3), perchloric acid (HClO4), hydrobromic acid (HBr) and hydroiodic acid (HI) are among the strong acids that completely dissociate in water. However, sulfuric acid and hydrochloric acid can give the greater pH change at the lowest cost. The pH value used for mineral releasing ranges from 7 to 0. Using a very low pH may cause the polymer beads to degrade. It should be noted that, however, when the valuable material is copper, for example, it is possible to provide a lower pH environment for the attachment of mineral particles and to provide a higher pH environment for the releasing of the mineral particles from the synthetic beads or bubbles.
According to some embodiments of the present invention, one part of the synthetic bead is functionalized with collectors while another part of same synthetic bead is functionalized to be hydrophobic as shown in FIGS. 16a and 16b. As shown in FIG. 16a, a synthetic bead 74 has a surface portion where polymer is functionalized to have collector molecules 73 with functional group 78 and molecular segment 76 attached to the surface of the bead 74. The synthetic bead 74 also has a different surface portion where polymer is functionalized to have hydrophobic molecules 179. In the embodiment as shown in FIG. 16b, the entire surface of the synthetic bead 74 can be functionalized to have collector molecules 73, but a portion of the surface is functionalized to have hydrophobic molecules 179 render it hydrophobic.
receiving unexpanded polymer microspheres and an ore slurry having mineral particles in a first cell, the unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles, causing the unexpanded polymer microspheres to expand in volume into expanded microspheres having an increased sphere surface area, and providing an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles; and
receiving the expanded polymer microsphere foam layer in a second cell, and causing the expanded polymer microspheres to collapse in volume into collapsed polymer microspheres having a reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles.
2. A method according to claim 1, wherein the first cell comprises a flotation cell.
3. A method according to claim 2, wherein the mineral particles are chalcopyrite.
4. A method according to claim 1, wherein the method comprises configuring the first cell with an agitator to cause or induce agitation to mix the ore slurry and polymer microspheres.
5. A method according to claim 1, wherein the method comprises configuring the unexpanded polymer microspheres with a blowing agent encapsulated therein that has a trigger temperature set below a predetermined temperature so as to cause the unexpanded polymer microspheres to expand in volume into the expanded polymer microspheres having the increased sphere surface area when received in the first cell.
6. A method according to claim 5, wherein the method comprises configuring the blowing agent with a liquid that responds to a change in temperature and transforms into a gas.
7. A method according to claim 5, wherein the method comprises configuring the blowing agent with a gas that responds to a change in temperature and transforms from a lower pressure phase into a higher pressure phase.
8. A method according to claim 5, wherein the method comprises filling the second cell with the expanded polymer microsphere foam layer or mineral rich foam, and pressurizing the expanded polymer microsphere foam layer or mineral rich foam to an elevated level, or chilling the expanded polymer microsphere foam layer or mineral rich foam to a lower temperature, such that the blowing agent reverses through a transition phase to return from a gas phase to a liquid phase or from a higher pressure phase to a lower pressure phase.
9. A method according to claim 1, further comprising maintaining the ore slurry at a predetermined temperature in the first cell, and the unexpanded polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand in volume into the expanded polymer microspheres having the increased sphere surface area when received in the first cell.
10. A method according to claim 9, wherein the method comprises cooling or chilling the unexpanded polymer microspheres to a temperature below the predetermined temperature before the unexpanded polymer microspheres are received into the first cell.
11. A method according to claim 1, wherein the expanded polymer microspheres are configured to become buoyant and create an increased bubble flux in the ore slurry, presenting surface area for mineral bearing particles to attach to and be lifted to the surface and form the expanded polymer microsphere foam layer.
12. A method according to claim 1, wherein the expanded polymer microsphere foam layer takes the form of an agglomerated mass of expanded spheres on the surface, said method further comprising skimming and moving the agglomerated mass to or spilling the agglomerated mass over into a spillover container and then moving the agglomerated mass to the second cell.
13. A method according to claim 1, wherein the method comprises configuring the second cell as a release tank in the form of a re-pressurization cell or tank or a condensation cell or tank configured to collapse the expanded polymer microspheres in volume into the collapsed polymer microspheres that results in the mechanical shearing off of the attached mineral particles.
14. A method to claim 1, wherein the method comprises separating the mineral particles from the collapsed polymer microspheres based at least partly on or due to gravitation separation, including where the mineral particles sink in the second cell and the collapsed polymer microspheres remain buoyant and float.
15. A method according to claim 1, wherein the method comprises providing either a mineral concentrate output having the mineral particles, or a discarded foam output having the collapsed polymer microspheres, or both from the second cell.
16. A method according to claim 1, wherein the method comprises configuring the molecules with a functional group for attaching the mineral particles.
17. A method according to claim 1, wherein the volume of the expanded polymer microspheres is about 50 times the volume of the unexpanded polymer microspheres.
a first cell comprising a flotation cell having a top part and a bottom part, the top part configured to receive an ore slurry having mineral particles, the bottom part configured to receive unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles, wherein the first cell is configured to maintain the ore slurry at a predetermined temperature, and the unexpanded polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand in volume into expanded polymer microspheres having an increased sphere surface area when received in the first cell, the first cell further configured to provide an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles; and
a second cell configured to receive the expanded polymer microsphere foam layer, wherein the second cell comprises a release tank in the form of a re-pressurization cell or tank or a condensation cell or tank configured to cause the expanded polymer microspheres to collapse in volume into collapsed polymer microspheres having a reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles.
19. Apparatus according to claim 18, wherein the first cell comprises an agitator configured to cause or induce agitation to mix the ore slurry and the unexpanded polymer microspheres or the expanded polymer microspheres or both.
20. Apparatus according to claim 18, wherein the blowing agent comprises a liquid that responds to a change in temperature and transforms into a gas.
21. Apparatus according to claim 18, wherein the blowing agent comprises a gas that responds to a change in temperature and transforms from a lower pressure phase into a higher pressure phase.
22. Apparatus according to claim 18, wherein the unexpanded polymer microspheres are cooled or chilled to a temperature below the predetermined temperature before the unexpanded polymer microspheres are received into the first cell.
23. Apparatus according to claim 18, wherein the expanded polymer microspheres are buoyant and create an increased bubble flux in the ore slurry, presenting surface area for mineral bearing particles to attach to and be lifted to the surface and form the expanded polymer microsphere foam layer.
24. Apparatus according to claim 18, wherein the expanded polymer microsphere foam layer takes the form of an agglomerated mass of expanded spheres on the surface and is caused to move to the second cell.
25. Apparatus according to claim 18, wherein the second cell is configured to be filled with the expanded polymer microsphere foam layer or mineral rich foam, and to be pressurized to an elevated level, or chilled to a lower temperature, such that the blowing agent reverses through a transition phase to return from a gas phase to a liquid phase or from a higher pressure phase to a lower pressure phase.
26. Apparatus according to claim 18, wherein the mineral particles separated from the collapsed polymer microspheres are caused by gravitation to sink in the second cell while the collapsed polymer microspheres remain buoyant and float.
27. Apparatus according to claim 18, wherein the second cell is also configured to provide a mineral concentrate output having the mineral particles, or a discarded foam output having the collapsed polymer microspheres, or both.
28. Apparatus according to claim 18, wherein the molecules comprise a functional group for attaching the mineral particles.
29. Apparatus according to claim 18, wherein the volume of the expanded polymer microspheres is about 50 times the volume of the unexpanded polymer microspheres.
30. Apparatus according to claim 18, wherein the mineral particles are chalcopyrite.
a first cell comprising a flotation cell having a top part and a bottom part, the top part configured to receive an ore slurry having mineral particles, the bottom part configured to receive polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles, wherein the first cell is configured to provide a polymer microsphere foam layer comprising the polymer microspheres with attached mineral particles, wherein the first cell is also configured to cause the polymer microspheres to expand in volume into expanded polymer microspheres having an increased sphere surface area, and wherein the first cell is further configured to maintain the ore slurry at a predetermined temperature, and the polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the polymer microspheres received in the first cell to expand in volume into the expanded polymer microspheres having the increased sphere surface area to provide a polymer microsphere foam layer; and
a second cell configured to receive the polymer microsphere foam layer, wherein the second cell further comprises a release tank in the form of a re-pressurization cell or tank or a condensation cell or tank configured to collapse the polymer microspheres in volume into collapsed polymer microspheres having a reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles.
32. Apparatus according to claim 31, wherein the second cell is also configured to provide a mineral concentrate output having the mineral particles.
a processor comprising a flotation cell configured to receive a plurality of synthetic beads, each of the synthetic beads comprising a surface and a plurality of molecules attached to the surface, the molecules comprising a functional group for attracting one or more of the mineral particles to the molecules, the synthetic beads comprising polymer microspheres, wherein the processor is also configured to cause the polymer microspheres to expand in volume into expanded polymer microspheres having an increased sphere surface area, wherein the processor is also configured to maintain the ore slurry at a predetermined temperature, and wherein the polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the polymer microspheres received into the processor to expand in volume into the expanded polymer microspheres having an increased sphere surface area; and
a releasing apparatus configured to receive the expanded polymer microspheres, and wherein the releasing apparatus comprises a re-pressurization cell or tank or a condensation cell or tank configured to cause the expanded polymer microspheres to collapse in volume into collapsed polymer microspheres that results in mechanical shearing off of the attached mineral particles.
34. Apparatus according to claim 33, wherein the releasing apparatus is configured to provide a mineral concentrate output having the mineral particles.
35. Apparatus according to claim 33, wherein the collapsed polymer microspheres in the releasing apparatus are pressurized to an elevated level, or chilled to a lower temperature, such that the blowing agent reverses through a transition phase to return from a gas phase to a liquid phase or from a higher pressure phase to a lower pressure phase.
36. Apparatus according to claim 33, wherein the mineral particles are chalcopyrite.
4746440 May 24, 1988 Seeger
4874507 October 17, 1989 Whitlock
6921426 July 26, 2005 Imamura
20010020603 September 13, 2001 Moorehead et al.
20030217953 November 27, 2003 Xu et al.
20050161406 July 28, 2005 Eades et al.
20100159225 June 24, 2010 Hodjat et al.
20110094970 April 28, 2011 Kincaid
Schramm, L. Emulsions, Foams, and Suspensions, Weinheim: Wiley-VCH, 2005, ISBN-13978-3-527-30743-2. [retrieved on Jun. 27, 2013). Retrieved from the Internet: <URL:http://image.sciencenet.cn/olddata/kexue.com.cn/bbs/upload/9076Emulsions%20Foams&20and%20Suspension%20-%20Fundamental%20and%20Applications.pdf>. Chapter 3.
Patent Publication Number: 20150083646
Inventors: Francis K. Didden (Wallingford, CT), Alan D. Kersey (South Glastonbury, CT), Michael A. Davis (Glastonbury, CT), Paul J. Rothman (Windsor, CT), Mark R. Fernald (Enfield, CT), Christian V. O'Keefe (Durham, CT), Douglas H. Adamson (Mansfield Center, CT)
Application Number: 14/387,692
International Classification: B03D 1/02 (20060101); C02F 1/24 (20060101); B03B 5/28 (20060101); B03D 1/14 (20060101); B03D 1/04 (20060101); B03D 1/08 (20060101);