Acoustic agglomeration system

Abstract

A system and method for flotation of particles. The system includes a flotation tank, a bubble generator and an acoustic generator. The floatation tank includes a substance inlet to supply a substance including particles to the flotation tank and a substance outlet to allow the substance to exit the flotation tank. The bubble generator is in fluid communication with the flotation tank, generates a plurality of bubbles and supplies the plurality of bubbles to the flotation tank. The acoustic generator is configured to generate and impart acoustic energy to the flotation tank. As acoustic energy is imparted to the flotation tank, the bubbles at least partially aggregate, and as the plurality of bubbles that are at least partially aggregated float, they connect with at least some of the particles such that at least some of the particles float.

Description

ACOUSTIC AGGLOMERATION SYSTEMREFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit under Convention priority of the filing date of Australian Patent Application No. 2024902440, filed 6 August 2024, hereby incorporated by reference in its entirety as if fully set forth herein.FIELD OF THE INVENTION

[0002] The present invention relates generally to the flotation of particles using an acoustic agglomeration system.BACKGROUND

[0003] Conventional devices / systems / methods for flotation of particles have been used to float particles out of substances to allow for their collection.

[0004] For example, WO 2017132694 Al discloses a method for separating beads and cells from a host fluid. The method includes flowing a mixture containing the host fluid, the beads, and the cells through an acoustophoretic device having an ultrasonic transducer, including a piezoelectric material driven by a drive signal to create a multi-dimensional acoustic standing wave. A drive signal is sent to drive at least one ultrasonic transducer to create the multi-dimensional acoustic standing wave. A recirculating fluid stream having a tangential flow path is located substantially tangential to the standing wave and separated therefrom by an interface region. A portion of the cells pass through the standing wave, and the beads are held back from the standing wave in the recirculating fluid stream at the interface region. Also disclosed is an acoustophoretic device having a coolant inlet adapted to permit the ingress of a cooling fluid into the device for cooling the transducer.

[0005] However, these conventional devices / systems / methods are limited in their ability to float particles.OBJECT OF THE INVENTION

[0006] It is an object of the present invention to overcome and / or alleviate one or more of the disadvantages of the prior art or provide the consumer with a useful or commercial choice.SUMMARY OF THE INVENTION

[0007] In one broad form, a system for flotation of particles, the system including a flotation tank including a substance inlet, configured to supply a substance to the flotation tank, wherein the substance includes the particles; and, a substance outlet, configured to allow the substance to exit the flotation tank; a bubble generator that is in fluid communication with the flotation tank, configured to generate a plurality of bubbles, and supply the plurality of bubbles to the flotation tank via a bubble inlet; and, an acoustic generator connected to the flotation tank, configured to generate and impart acoustic energy to the flotation tank; wherein the system is configured such that: as the acoustic energy is imparted to the flotation tank, the plurality of bubbles at least partially aggregate; and, as the plurality of bubbles that are at least partially aggregated float, they connect with at least some of the particles such that at least some of the particles float.

[0008] In one example, the plurality of bubbles are fine bubbles or microbubbles.

[0009] In one example, the bubble generator generates the plurality of bubbles using at least one of: a centrifugal pump; a venturi tube; an inline mixer; porous media; and, a rotating packed bed reactor.

[0010] In one example, the venturi tube includes: a fluid inlet and wherein the venturi tube is configured to receive fluid through the fluid inlet via a peristaltic pump; an outlet; and, an air inlet.

[0011] In one example, fluid flows in the outlet at supersonic or subsonic speed.

[0012] In one example, the flotation tank includes a fluid outlet that is in fluid communication with the peristaltic pump and is configured to supply the peristaltic pump with fluid.

[0013] In one example, the acoustic generator includes an ultrasonic transducer and the acoustic energy, when imparted to the flotation tank, is configured to create a pressure wave within the flotation tank.

[0014] In one example, the pressure wave is in the form of a standing wave including nodes and antinodes.

[0015] In one example, the plurality of bubbles at least partially aggregate at the nodes or antinodes of the pressure wave.

[0016] In one example, the pressure wave has a bubble resonance radius and wherein: if an individual bubble has a radius that is less than the bubble resonance radius, that respective bubble aggregates at the antinode; and, if an individual bubble has a radius that is greater than the bubble resonance radius, that respective bubble aggregates at the node.

[0017] In one example, the system includes a bubble separator that is configured to increase the buoyancy of the plurality of bubbles.

[0018] In one example, the bubble separator includes at least one of: an inclined plane; a cyclonic structure; and, porous media.

[0019] In one example, the system, while in use, is configured to operate continuously.

[0020] In one example, the substance inlet is located higher in the flotation tank than the substance outlet and the substance is configured to flow from the substance inlet to the substance outlet.

[0021] In one example, the acoustic generator imparts acoustic energy to the flotation tank at a part of the flotation tank that is lower than the bubble inlet and the acoustic energy is configured to increase the buoyancy of the plurality of bubbles.

[0022] In one example, the plurality of bubbles are configured to float towards the top of the flotation tank.

[0023] In one example, the plurality of bubbles are configured to float in opposition to the substance flow, to increase the possibility of the plurality of bubbles connecting with at least some of the particles.

[0024] In one example, the plurality of bubbles are sufficiently buoyant to float the connected at least some particles.

[0025] In one example, the particles are at least one of: oil droplets; minerals; coal; waste; and, waste for recycling.

[0026] In one broad form, a method for floating particles, the method including: receiving a substance that contains the particles in a flotation tank, via a substance inlet; generating a plurality of bubbles via a bubble generator that is in fluid communication with the flotation tank; receiving the plurality of bubbles in the flotation tank, via a bubble inlet; generating acoustic energy via an acoustic generator; and, imparting acoustic energy to the flotation tank so that the plurality of bubbles at least partially aggregate; wherein as the plurality of bubbles that are at least partially aggregated float, they connect with at least some of the particles such that at least some of the particles float.

[0027] One aspect of the present disclosure provides a system for flotation of particles, the system including: a flotation tank including: a substance outlet configured to allow a substance to exit the flotation tank; a bubble generator that is in fluid communication with the flotation tank, configured to receive the substance with the particles and to generate a plurality of bubbles, such that the generated bubbles are pre-loaded with the particles, wherein the bubble generator supplies the pre-loaded bubbles to the flotation tank via a bubble inlet; and, an acoustic generator connected to the flotation tank, configured to generate and impart acoustic energy to the flotation tank; wherein the system is configured such that: as the acoustic energy is imparted to the flotation tank, the plurality of bubbles at least partially aggregate.

[0028] One aspect of the present disclosure provides a method for floating particles, the method including: receiving a substance at a bubble generator; generating a plurality of bubbles via the bubble generator, such that the generated bubbles are pre-loaded with the particles, wherein the bubble generator is in fluid communication with a flotation tank; receiving the plurality of bubbles in the flotation tank, via a bubble inlet; generating acoustic energy via an acoustic generator; and, imparting acoustic energy to the flotation tank so that the plurality of bubbles at least partially aggregate; wherein as the plurality of bubbles that are at least partially aggregated float.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention are described below by way of example only with reference to the accompanying drawings, in which:

[0030] Figure 1 is a schematic diagram showing an example of a system for separating particles by flotation;

[0031] Figure 2 is a flow diagram showing an example of a method for separating particles by flotation; and,

[0032] Figure 3 is a schematic diagram showing an example of a system for separating particles by flotation.DETAILED DESCRIPTION

[0033] The present invention relates to flotation of particles using an acoustic agglomeration system. Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description.

[0034] In this patent specification, adjectives such as first and second, left and right, above and below, top and bottom, upper and lower, rises and falls, upward and downward, etc., are used solely to define one element or method step from another element or method step without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as “comprises” or “includes” are not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set of elements or method steps included in a particular embodiment of the present invention.

[0035] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

[0036] A system for flotation of particles will now be described with reference to Figure 1.

[0037] The system 100 includes a flotation tank 110, a bubble generator 120 and an acoustic generator 130.

[0038] The flotation tank 110 includes a substance inlet 111, the substance inlet 111 being configured to supply a substance to the flotation tank, and a substance outlet 112, the substance outlet 112 being configured to allow the substance to exit the flotation tank. The substance includes the particles that the system 100 seeks to float.

[0039] The bubble generator 120 is in fluid communication with the flotation tank 110 via a bubble inlet 121 and the bubble generator 120 is configured to generate a plurality of bubbles and supply the plurality of bubbles to the flotation tank 110 via the bubble inlet 121.

[0040] In one arrangement, the substance with the particles is added to the bubble generator 120 such that the generated bubbles interact with the particles at the bubble generator 120. Thus, the bubbles generated are pre-loaded with the particles. When pre-loading the generated bubbles, it is possible to also supply the substance via the substance inlet 111. However, it is also possible to use the pre-loaded bubbles without further supplying the substance via the substance inlet 111.

[0041] The acoustic generator 130 is connected to the flotation tank 110 and is configured to generate and impart acoustic energy to the flotation tank 110. In one arrangement, the acoustic generator 130 is disposed on the sidewall of the flotation tank 110 such that the generated acoustic energy is transmitted into the flotation tank 110.

[0042] As acoustic energy, generated by the acoustic generator 130, is imparted to the flotation tank 110, at least some of the plurality of bubbles supplied to the flotation tank 110 at least partially aggregate. As some of the plurality of bubbles that partially connect with particles within the substance at least partially aggregate, the partially aggregated bubbles float in the substance. This connection with the at least partially aggregated bubbles causes at least some of the particles to float. In contrast to conventional devices / systems, the system 100 is capable of floating a wider variety of particle types and particle sizes.

[0043] For example, as high-quality, easily accessible mineral / ore deposits continue to deplete, lower-grade sources of minerals and ores may instead be used as substitute sources for metals and other materials. These lower-grade sources are often a combination of multiple materials, which can include synthetic materials, and only a small quantity of the material combination is desirable. In order to extract the desirable materials from these material combinations, the material combinations may be disintegrated or ground to constitute a substance so that the desirable materials can be released from undesirable materials and floated using the system 100, to enable their extraction. In another example, substances may include contaminants which are desirable to remove. The contaminants can be removed by the system 100 by floating the contaminants to the top of the flotation tank 110 so they be extracted from the substance.

[0044] A number of further features will now be described.

[0045] In one example, the plurality of bubbles are fine bubbles or microbubbles. Further, each of the plurality of bubbles may have a diameter that is at least one of 10 to 200 micrometers, 30 to 180 micrometers, 50 to 160 micrometers, 70 to 140 micrometers, 90 to 120 micrometers and approximately 100 micrometers.

[0046] As previously discussed, lower-grade sources of minerals and ores may include a combination of multiple materials, where only a small quantity of the material combination is desirable. In order to incorporate these material combinations into a substance, the material combinations may need to be finely ground, potentially as fine as 10 to 20 micrometers. For the aggregated plurality of bubbles to be able to efficiently connect with, and therefore float, the desirable particles the buoyancy of the aggregated bubbles can be increased using fine bubbles or microbubbles.

[0047] In one example, the bubble generator 120 generates the plurality of bubbles using at least one of a centrifugal pump, a venturi tube, an inline mixer, porous media and a rotating packed bed reactor.

[0048] In conventional me thods / systems / de vices, acoustic transducers can be used via cavitation to generate the plurality of bubbles and to aggregate the plurality of bubbles. However, there can be disadvantages that reduce the efficiency of bubble generation, bubble agglomeration and bubble connection with the particles. Firstly, the number of bubbles produced via cavitation is lower than via a bubble generator, such as a venturi tube. Secondly, efficiency operation of the ultrasonic wave generated by the transducer to generate the bubbles is distinct from the efficient operation of the transducer to agglomerate the bubbles. Therefore, the use of acoustic transducers to generate and aggregate the plurality of bubbles can increase the time required to prepare a conventional system / device to float particles and reduce the efficiency of particle floating, leading to more desirable particles lost during the flotation process.

[0049] System 100 can avoid these issues by separating the acoustic generator 130, which generates the acoustic energy to aggregate the plurality of bubbles, and the bubble generator 120, which generates the plurality of bubbles.

[0050] In one example, the venturi tube includes a fluid inlet and wherein the venturi tube is configured to receive fluid through the fluid inlet via a peristaltic pump, an outlet and an air inlet. Further, the flotation tank 110 may include a fluid outlet that is in fluid communication with theperistaltic pump and is configured to supply the peristaltic pump with fluid. Additionally, the fluid flow through the fluid inlet may be at least one of 0.2 L / min to 2.2 L / min, 0.4 L / min to 2 L / min, 0.6 L / min to 1.8 L / min, 0.8 L / min to 1.6 L / min, 1 L / min to 1.4 L / min and approximately 1.2 L / min, the venturi tube may have an inner diameter of at least one of 0.1 mm to 2 mm, 0.2 mm to 1.8 mm, 0.4 mm to 1.6 mm, 0.6 mm to 1.4 mm, 0.8 mm to 1.2 mm and approximately 1 mm and the air flow through the air inlet may be at least one of 1 ml / min to 80 ml / min, 10 ml / min to 70 ml / min, 20 ml / min to 60 ml / min, 30 ml / min to 50 ml / min and approximately 40 ml / min.

[0051] As noted above, the separation of the bubble generator 120 from the acoustic generator 130 allows for the generation of the plurality of bubbles and the agglomeration of the plurality of bubbles to be managed by separate devices. The separation of the bubble generator 120 from the acoustic generator 130 also allows for the calibration / tuning of the bubble generator 120 to be distinct from the acoustic generator 130.

[0052] For example, the fluid through the inlet / inner diameter / air flow through the inlet of the venturi tube can be altered in order to adjust the size and number of bubbles generated by the bubble generator 120 without the need to adjust the acoustic generator 130. The system 100 therefore allows for the generated bubbles to be of a suitable size and number to more efficiently connect with and float desirable particles from the substance.

[0053] In one example, fluid flows in the outlet of the venturi tube at supersonic or subsonic speed. With a supersonic or subsonic fluid flow outlet speed, bubble generation characteristics can be altered based on the inlet fluid flow rate and the shape of the venturi tube.

[0054] For a person skilled in the art, it may be simpler or less resource intensive to adjust the inlet fluid flow rate or the venturi tube shape, depending on their implementation of the present invention. As such, the utilisation of a supersonic or subsonic fluid flow outlet speed can allow for more types of particles that the system 100 can float.

[0055] In one example, the acoustic generator 130 includes an ultrasonic transducer and the acoustic energy, when imparted to the flotation tank 110, is configured to create a pressure wave within the flotation tank 110. Further, the pressure wave may be in the form of a standing wave including nodes and antinodes and the plurality of bubbles may at least partially aggregate at the nodes or antinodes of the pressure wave. Additionally, the plurality of bubbles have a bubble resonance radius and wherein if an individual bubble has a radius that is less than the bubbleresonance radius, that respective bubble aggregates at the antinode and if an individual bubble has a radius that is greater than the bubble resonance radius, that respective bubble aggregates at the node. A person skilled in the art may also appreciate that utilizing a wave frequency that matches the bubble resonance radius to the bubble size can increase bubble aggregation efficiency.

[0056] In one example, the system 100 includes a bubble separator that is configured to increase the buoyancy of the plurality of bubbles. Further, the bubble separator includes at least one of a plurality of inclined planes, a cyclonic structure and porous media. As the flotation tank 110 receives the plurality of bubbles, a bubble separator can be used to increase the buoyancy of the bubbles such that they are more effective in rising in the flotation tank and can potentially connect with more particles, so that particle floating efficiency is increased. The bubble separator may also increase the efficiency of acoustic agglomeration, reducing the number of bubbles required to be generated and improving power efficiency of the system 100.

[0057] In one example, wherein the system 100, while in use, is configured to operate continuously. Further, the substance inlet 111 may be located higher in the flotation tank 110 than the substance outlet 112 and the substance is configured to flow from the substance inlet 111 to the substance outlet 112. Additionally, the acoustic generator 130 may impart acoustic energy to the flotation tank 110 at a part of the flotation tank 110 that is lower than the bubble inlet 121 and the acoustic energy is configured to increase the buoyancy of the plurality of bubbles so that the bubbles does not flow out to the outlet with the substance. The plurality of bubbles may also be configured to float in opposition to the substance flow, to increase the possibility of the plurality of bubbles connecting with at least some of the particles.

[0058] The continuous operation of the system 100 allows for continuous feeding of new substance and continuous floating of particles in the flotation tank 110. In one example, by supplying substance through the substance inlet 111, the substance supply rate can be adjusted independently from bubble size and number. This can increase bubble incidence rates with the particles, leading to an increase number of floated particles.

[0059] In another example, the substance may pass through the bubble generator 120, where the substance is placed in proximity with the plurality of bubbles while the plurality of bubbles are in a higher turbulence environment. This higher turbulence environment can increase bubble incidence rates with the particles, leading to an increase number of floated particles.

[0060] Conventional methods / systems / devices typically utilise batch systems where flotation efficiency, time efficiency and power efficiency are reduced as the system / device are required to be reset whenever new substance is to be introduced. As such, the system 100 operating continuously can avoid these reductions in efficiency by removing the resetting required by a batch system.

[0061] The system 100 may operate in a continuous manner by a downstream of substance from the substance inlet 111 located in a higher portion of the flotation tank 110 than the substance outlet 112 which meets an upstream of the plurality of bubbles which have increased buoyancy from the acoustic energy imparted by the acoustic generator 130. As the downstream of substance meets the upstream of the plurality of bubbles, there is an increased efficiency in bubble connections with the particles by increasing the residence time of the particles, leading to an increased number of particles floated.

[0062] The bubble generation, acoustic energy imparted, acoustic wave frequency, amount of substance and particle density in the substance can be dynamically altered during the continuous operation of the system 100 in response to demand while maintaining flotation efficiency while maintaining flotation efficiency in contrast to conventional batch devices / systems which can lose efficiency in response to reduced demand.

[0063] In one example, the plurality of bubbles are sufficiently buoyant to float the connected at least some particles. Further, the floated particles may be configured to float to the top of the flotation tank to allow for their collection.

[0064] In one example, wherein the substance is an aqueous solution including surfactant. Further, the particles in the aqueous solution may be able to be hydrophobised by the surfactant.

[0065] In one example, the particles are fine and have low compressibility. The system 100 is capable of floating fine particles that have low compressibility, particularly when utilizing microbubbles, which improves incidence and power efficiency. Further, the particles may be at least one of oil droplets, minerals, coal, waste and waste for recycling. Additionally, the diameter of the particles may be at least one of 10 to 300 micrometers, 40 to 270 micrometers, 70 to 240 micrometers, 100 to 210 micrometers, 130 to 180 micrometers and approximately 150 micrometers.

[0066] A method for floating particles will now be described with reference to Figure 2.

[0067] At step 210, a substance which contains the particles is received in a flotation tank via a substance inlet such as the inlet 111. As described above, in an arrangement where the bubbles are pre-loaded with the particles, the substance is received at the bubble generator 120. In another arrangement, the particles can be introduced at the bubble generator 120 and the substance inlet 111.

[0068] At step 220, a plurality of bubbles is generated via a bubble generator (such as 120) that is in fluid communication with the flotation tank. The plurality of bubbles connects with at least some of the particles during or after the bubble generation.

[0069] At step 221, the flotation tank receives the plurality of bubbles via a bubble inlet.

[0070] At step 230, acoustic energy is generated via an acoustic generator (such as 130).

[0071] At step 231 , the acoustic energy is imparted to the flotation tank so that the plurality of bubbles at least partially aggregate.

[0072] At step 232, as the plurality of bubbles that have been aggregated float, the bubbles then connect with at least some of the particles from the substance inlet 111 such that at least some of the particles float.

[0073] The flotation of these particles within the flotation tank allows for their collection.

[0074] In contrast to conventional methods, this method for floating particles is capable of floating a larger variety of particle types and particle sizes.

[0075] An example of a system for floating particles will now be described with reference to Figure 3.

[0076] The system 300 includes a flotation tank 310, a bubble generator in the form of a venturi tube 350 and an acoustic generator 330.

[0077] The flotation tank 310 includes a substance inlet 311, the substance inlet 311 being configured to supply a substance to the flotation tank, and a substance outlet 312, the substance outlet 312 being configured to allow the substance to exit the flotation tank. The substance includes the particles that the system 300 seeks to float.

[0078] The substance inlet 311 is located above the substance outlet 312 such that at least some of the substance flows from the substance inlet 311 down the flotation tank 310 to the substance outlet 312 in a continuous manner while the system 300 is in operation.

[0079] The venturi tube 350 is in fluid communication with the flotation tank 310 via a bubble inlet 321. The venturi tube 350 is configured to receive air flow from an air inlet 352 and fluid via a fluid inlet 351. Upon receiving air flow and fluid, the venturi tube 350 is configured to generate a plurality bubbles, which are then supplied to the flotation tank via a venturi tube outlet 353 to the bubble inlet 321. The venturi tube 350 receives fluid via a peristaltic pump 354 and the peristaltic pump 354 is configured to control the rate of fluid flow into the venturi tube 350. The peristaltic pump 354 is configured to receive fluid (which includes the particles) from the flotation tank via a flotation fluid outlet 322. The arrows 323, 355 and 356 indicate the direction of fluid flow via the flotation tank 310, peristaltic pump 354 and venturi tube 350. Therefore, the arrangement shown in Fig. 3 is a combination of the particles being pre-loaded at the bubble generator (in this case, via the fluid inlet 351) and the particles being introduced at the substance inlet 311.

[0080] The acoustic generator 330 is connected to the flotation tank 310 and is configured to generate and impart acoustic energy to the flotation tank 310.

[0081] As acoustic energy, generated by the acoustic generator 330, is imparted to the flotation tank 310, at least some of the plurality of bubbles supplied to the flotation tank 310 at least partially aggregate. As some of the plurality of bubbles at least partially aggregate, they float in the substance and can connect with at least some of the particles within the substance. This connection with the at least partially aggregated bubbles causes at least some of the particles to float.

[0082] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. Numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications andvariations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

THE INVENTION AS CLAIMED IS AS FOLLOWS:1) A system for flotation of particles, the system including: a) a flotation tank including: i) a substance inlet, configured to supply a substance to the flotation tank, wherein the substance includes the particles; and, ii) a substance outlet, configured to allow the substance to exit the flotation tank; b) a bubble generator that is in fluid communication with the flotation tank, configured to generate a plurality of bubbles and supply the plurality of bubbles to the flotation tank via a bubble inlet; and, c) an acoustic generator connected to the flotation tank, configured to generate and impart acoustic energy to the flotation tank; d) wherein the system is configured such that: i) as the acoustic energy is imparted to the flotation tank, the plurality of bubbles at least partially aggregate; and, ii) as the plurality of bubbles that are at least partially aggregated float, they connect with at least some of the particles such that at least some of the particles float.2) A system according to claim 1, wherein the plurality of bubbles are fine bubbles or microbubbles.3) A system according to claim 1 or claim 2, wherein the bubble generator generates the plurality of bubbles using at least one of: a) a centrifugal pump; b) a venturi tube; c) an inline mixer; d) porous media; and, e) a rotating packed bed reactor.4) A system according to claim 3, wherein the venturi tube includes: a) a fluid inlet and wherein the venturi tube is configured to receive fluid through the fluid inlet via a peristaltic pump; b) an outlet; and, c) an air inlet.5) A system according to claim 4, wherein fluid flows in the outlet at supersonic or subsonic speed.6) A system according to claim 4 or claim 5, wherein the flotation tank includes a fluid outlet that is in fluid communication with the peristaltic pump and is configured to supply the peristaltic pump with fluid.7) A system according to any one of claims 1 to 6, wherein the acoustic generator includes an ultrasonic transducer and the acoustic energy, when imparted to the flotation tank, is configured to create a pressure wave within the flotation tank.8) A system according to claim 7, wherein the pressure wave is in the form of a standing wave including nodes and antinodes.9) A system according to claim 8, wherein the plurality of bubbles at least partially aggregate at the nodes or antinodes of the pressure wave.10) A system according to claim 9, wherein the pressure wave has a bubble resonance radius and wherein: a) if an individual bubble has a radius that is less than the bubble resonance radius, that respective bubble aggregates at the antinode; and, b) if an individual bubble has a radius that is greater than the bubble resonance radius, that respective bubble aggregates at the node.11) A system according to any one of claims 1 to 10, wherein the system includes a bubble separator that is configured to increase the buoyancy of the plurality of bubbles.12) A system according to claim 11, wherein the bubble separator includes at least one of: a) an inclined plane; b) a cyclonic structure; and, c) porous media.13) A system according to any one of claims 1 to 12, wherein the system, while in use, is configured to operate continuously.14) A system according to any one of claims 1 to 13, wherein the substance inlet is located higher in the flotation tank than the substance outlet and the substance is configured to flow from the substance inlet to the substance outlet.15) A system according to claim 14, wherein the acoustic generator imparts acoustic energy to the flotation tank at a part of the flotation tank that is lower than the bubble inlet and the acoustic energy is configured to increase the buoyancy of the plurality of bubbles.16) A system according to claim 14 or claim 15, wherein the plurality of bubbles are configured to float towards the top of the flotation tank.17) A system of claim 16, wherein the plurality of bubbles are configured to float in opposition to the substance flow, to increase the possibility of the plurality of bubbles connecting with at least some of the particles.18) A system of claim 17, wherein the plurality of bubbles are sufficiently buoyant to float the connected at least some particles.19) A system according to any one of claims 1 to 18, wherein the particles are at least one of: a) oil droplets; b) minerals; c) coal; d) waste; and, e) waste for recycling.20) A system according to any one of claims 1 to 19, wherein a substance with particles is added to the bubble generator to pre-load the generated bubbles with the particles.21) A method for floating particles, the method including: a) receiving a substance that contains the particles in a flotation tank, via a substance inlet; b) generating a plurality of bubbles via a bubble generator that is in fluid communication with the flotation tank; c) receiving the plurality of bubbles in the flotation tank, via a bubble inlet; d) generating acoustic energy via an acoustic generator; and, e) imparting acoustic energy to the flotation tank so that the plurality of bubbles at least partially aggregate; f) wherein as the plurality of bubbles that are at least partially aggregated float, they connect with at least some of the particles such that at least some of the particles float.22) A method of claim 21, further comprising adding a substance with particles to the bubble generator to pre-load the generated bubbles with the particles.23) A system for flotation of particles, the system including:a) a flotation tank including: i) a substance outlet configured to allow a substance to exit the flotation tank; b) a bubble generator that is in fluid communication with the flotation tank, configured to receive the substance with the particles and to generate a plurality of bubbles, such that the generated bubbles are pre-loaded with the particles, wherein the bubble generator supplies the pre-loaded bubbles to the flotation tank via a bubble inlet; and, c) an acoustic generator connected to the flotation tank, configured to generate and impart acoustic energy to the flotation tank; d) wherein the system is configured such that: i) as the acoustic energy is imparted to the flotation tank, the plurality of bubbles at least partially aggregate.24) A method for floating particles, the method including: a) receiving a substance at a bubble generator; b) generating a plurality of bubbles via the bubble generator, such that the generated bubbles are pre-loaded with the particles, wherein the bubble generator is in fluid communication with a flotation tank; c) receiving the plurality of bubbles in the flotation tank, via a bubble inlet; d) generating acoustic energy via an acoustic generator; and, e) imparting acoustic energy to the flotation tank so that the plurality of bubbles at least partially aggregate; wherein as the plurality of bubbles that are at least partially aggregated float.

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