Abstract: A process of separating a desired constituent from a mixture of particulate matter including the steps of: conditioning a liquid mixture of particulate matter with a frothing agent to create a pulp; aerating the pulp to generate a float fraction of froth supported on the surface of a non-float fraction of pulp; separating a portion of froth from the float fraction; draining the separated froth; washing the separated froth with a liquid to dislodge particles comprising one or more of non-selectively attached, entrained, and entrapped particles; and recovering the washed froth, is disclosed herein. Also disclosed herein are a froth cleaning apparatus and a froth flotation apparatus for separating a desired constituent from a mixture of particulate matter.

Abstract: The invention relates to a rotor used in the flotation mechanism in the concentration of ores. According to the invention, upper part of the rotor chambers under the rotor cover are formed to be downward inclined from the outer edge of the chambers into the core so that they form an angle between 5 to 70 degrees with the horizontal plane. In addition the upper surface of the rotor cover can be inclined upwards raising from around the rotor shaft towards the outer edge at an angle between 5-70 degrees. With the means inside and above the rotor the slurry is directed upwards through the stator of the flotation mechanism. The developed rotor improves the suspension of coarse particles with high specific gravity within a flotation machine. The invention relates also to a method for inverting the material flow disharging from the rotor.

Abstract: The invention relates to a flotation machine, particularly to a flotation machine rotor, that is used for dispersing air, supplied via the rotor axis, to the surrounding slurry, and in which rotor there are formed alternating air ducts and slurry grooves, so that the ends of both the air ducts and the slurry grooves, projecting outwardly from the rotor, form the outer surface of the rotor According to the invention the air ducts (3,15) are arranged in the rotor at essentially equal distances, starting radially from the rotor outer surface, so that the air ducts (3,15) form in the center part of the rotor a space (6,17) for the slurry, in which space the slurry surrounding the rotor is to be made to flow along the slurry grooves (5, 16) provided in between the air ducts (3,15).

Abstract: The invention relates to a flotation machine which at least contains a flotation cell having a means for feeding slurry in the flotation cell, a means for feeding air into the slurry and producing froth, a means for removing froth from the flotation cell and a means for removing tailings from the flotation cell. According to the invention the flotation cell (1,21) is provided with at least one rotating froth removal device (8,26) immersed at least partly in the froth (9,27) and so shaped that one end of the froth removal device (8,26) is extendible over the launder (12) attached to the flotation cell (1) in order to recover the froth (9,27) from the flotation cell (1,21) using the centrifugal force generated by the froth removal device (8,26).

Abstract: The invention relates to a flotation machine and method for improving flotation effect in the flotation machine which is provided with members for feeding material to be treated in the flotation machine, members for removing the treated material out of the flotation machine at least in the upper part of the flotation machine and in the bottom part of the flotation machine, a mixing mechanism comprising a stator and a rotor located inside the machine, air supply means for supplying air to the mixing mechanism and forming a froth bed in the upper part of the flotation machine, at least one member for adjusting free space of the froth bed created in the flotation machine. According to the invention a conducting member is installed inside the flotation machine in order to add flowing material for slurry dilution in the slurry area essentially above the top art of the rotor, but below the froth zone.

Abstract: An apparatus for recovering a desired fraction of a raw material bearing the desired fraction has a vessel or cell defining a treatment chamber therein, with an inlet into the chamber for introducing a slurry of raw material to be treated into the chamber. An attrition zone is defined in a portion of the chamber proximate the inlet in the flow path of material introduced into the chamber, the particles being caused to impact against each other in the attrition zone to cause attritioning thereof. A floatation zone is defined in a distal portion of the chamber, in flow communication with the attrition zone, in which attritioned particles from the attrition zone can be contacted with gas bubbles to form a froth phase separated from the slurry by a slurry-froth interface such that the desired fraction is either selectively taken up into the froth phase by the gas bubbles or selectively left behind in the slurry. An outlet from the chamber for the froth phase is present.

Abstract: An impeller for use with apparatus to enhance mixing of a gas and a liquid, as used for example in froth flotation apparatus, having a substantially upright portion (11) substantially parallel to the axis of rotation (17), and a plurality of vanes (12) extending outwardly therefrom, at least some of the vanes (12) having an upper part (19) adapted to induce liquid flow generally downwardly towards the impeller and a lower part (20) adapted to induce liquid flow generally upwardly towards the impeller, wherein the impeller further comprises barrier means (14) at least partially dividing the upper and lower parts, and a gas input situated on the same side of the barrier means (14) as the lower part (20). The barrier means (14) may comprise a flange like member in a plane generally perpendicular to the axis of rotation (17) and may intersect, or be integral with at least part of the vanes.

Abstract: A superb centrifugal flotation cell with a rotating feed, is provided for use in an effective separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary pipe and a rotating feed line comprising a centrifugal rotating downfeeder. The slurry is centrifugally discharged from the rotating downfeeder into the flotation chamber where the slurry is separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles for further processing.

Abstract: A mixing system in a tank provides a flotation cell for froth collection of minerals such as metallic ores thereby separating such ores from other materials with which they are mined and enabling a concentrated ore component to be collected. The mixing system maintains particles containing the ores in a circulating liquid suspension in a contact zone where bubbles are discharged. Ore particles are attracted and attached to the bubbles. The bubbles rise and float to the top of the liquid for collection of the concentrated ores. The mixing system includes a radial flow impeller and an axial flow impeller which are attached for rotation on a common shaft, with the axial flow impeller below the radial flow impeller. The radial flow impeller is disposed in a space between a disc, which rotates with the radial flow impeller and another disc which is stationary, and may be a flange of a pipe around the shaft and extending above the surface of the liquid.

Abstract: A froth flotation cell comprising a tank and an impeller rotatably disposed in the tank for suspending solids and dispersing air in a pulp phase or slurry in the tank, thereby generating froth from the pulp phase. A plurality of radially oriented launders are placed near the top of the tank and have one end connected to an outer launder adjacent the outer periphery of the tank. A secondary launder, concentric with the outer launder may also be placed near the top of the tank and attached to the second ends of the radial launders. The secondary launder is attached to a dispersing mechanism located around the impeller. The secondary launder is in fluid communication with the radial launders, and the radial launders are likewise in fluid communication with the central launder. This provides a network of launders which collects froth at various locations throughout the flotation cell and causes rapid removal of froth from the flotation cell.

Abstract: Excessive vibration in industrial mixers such as flotation cells and draft tube mixers is attenuated by connecting a vibration dampening device to a rotor or impeller which is disposed in a mixing tank for pumping a nonhomogeneous fluidic material placed in the tank. In a draft tube mixer, where the rotor is connected to a drive shaft in turn connected to a motor for rotating the rotor, the vibration dampening device is connected to the shaft on a side of the rotor opposite the motor. In a froth flotation cell, if the rotor is hollow, the vibration dampening device is disposed inside a pipe in turn mounted inside the rotor along an axis thereof. The vibration dampening device takes the form of a tuned mass dampener tuned to a resonance frequency of the particular mixing apparatus.

Abstract: The invention realises a reactor for liquids purification comprising: a tank containing the liquid to be purified; a plurality of upper injectors suitable for introducing in the tank said liquid to be purified with an aeriform substance dispersed in it in the form of bubbles; one or more blades arranged inside said tank and connected with a rotating shaft; one or more intermediate injectors cooperating with said first interception means suitable for sucking the liquid up and introducing it again in the tank in a lower position in comparison with said upper injectors. Said reactor comprises at least a low box, arranged at an intermediate height in said tank, suitable for receiving the descending liquid during a purification phase, which is supplied with interception means suitable for permitting the suction and the re-flowing of said liquid inside said tank.

Abstract: An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

Abstract: The invention realizes a baffle for a reactor for liquids purification, said reactor comprising: a tank containing the liquid to be purified; a plurality of injectors suitable for introducing in the tank said liquid to be purified; one or more rotating blades arranged inside said tank, suitable for keeping agitated said liquid to be purified. Said baffle is applied to at least one of said one or more blades and it is formed of a disk supplied with a plurality of through openings suitable for favoring, during the rotation of said blades, the passing of the descending flow of liquid during the purification, and of the ascending flow of aeriform substance dispersed in said liquid, in order to favor the stabilization of the turbulent motion of the liquid itself in correspondence with said blades.

Abstract: A method for rupturing microalgae in an aqueous suspension is disclosed. In one embodiment the aqueous suspension is passed through a constriction into a liquid phase at a pressure sufficient to rupture the cells by circulating the aqueous suspension through a constriction in a pump loop at a pressure and a percent recycle sufficient to rupture the cells. Cells of the alga Dunaliella salina can be ruptured by the method of the invention to promote froth flotation and mechanical filtration of the cells for recovery of mixed carotenoids.

Abstract: A flotation cell row including a row of cells through which, in use, a process liquid flows in turn, including a first bank of cells having a last cell 4 being the most downstream cell and a second bank of cells having a first cell 5 being the most upstream cell, the second bank being the bank immediately downstream of the first bank, in which one or both of the last cell 4 and the first cell 5 are structured to define a port 37 having a rim through which, in use, the process liquid flows from the last cell 4 to the first cell 5, and a valve member 10 mounted for movement between a closed position abutting the rim 44 and an open position spaced from rim 44, to control flow of process liquid through the port 37.

Abstract: A user-friendly centrifugal flotation cell with a rotating drum, is provided for use in an efficient separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary downfeeder to a centrifuge comprising a rotating flotation cell. The aerated slurry is centrifugally separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles. The froth is processed by froth flotation in a froth flotation chamber.

Abstract: An apparatus for extracting floatable minerals from a slurry (3). Slurry (3) is fed into a tank (2) via a feed inlet (25) and agitated and aerated so as to create an upper zone containing froth enriched with the floatable minerals. The agitation and aeration are also regulated to create a lower zone (41) containing a relatively dense or coarse component of the slurry (3), and an intermediate zone (42) containing a substantially less dense or finer component of the slurry (3). The surface froth is progressively withdrawn via a launder (30) thereby to produce a flotation concentrate. Similarly, the relatively dense component of the slurry (3) is progressively withdrawn from the lower zone (41) via a bottom inlet (26), and the relatively less dense of the slurry (3) is progressively withdrawn from the intermediate zone (42) via a side outlet (28).

Abstract: A superb centrifugal flotation cell with a rotating feed, is provided for use in an effective separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary pipe and a rotating feed line comprising a centrifugal rotating downfeeder. The slurry is centrifugally discharged from the rotating downfeeder into the flotation chamber where the slurry is separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles for further processing.

Abstract: A flash flotation device (1) comprises a tank (2) to contain slurry (3) incorporating minerals to be extracted, a feed inlet (25) for admission of slurry (3) into the tank (2), agitation means (10) to agitate the slurry (3) within the tank (2), aeration means to aerate the slurry (3) whereby floatable minerals in suspension form a surface froth for removal via froth lip (29), a bottom outlet (26) for withdrawal of relatively coarse or dense components of the slurry (3) from the tank (2), and a side outlet (28) to regulate the level of slurry (3) in the tank (2).

Abstract: The present invention provides a process that employs both non-selective flotation and oxidative leaching of the resulting concentrates to recover an increased amount of copper from porphyry copper ores. The non-selective flotation step uses collectors and conditions, such as pH, that are conducive to the strong flotation of sulfide minerals generally. In the oxidative leach, the copper sulfide minerals in the concentrate fraction are oxidized to copper compounds, which are soluble in the leach solution. The oxidative leach includes the use of ammonia and sulfite under agitation leaching conditions to convert the copper sulfide minerals into ammonia soluble forms.

Abstract: The present invention provides a process that employs both non-selective flotation and oxidative leaching of the resulting concentrates to recover an increased amount of copper from porphyry copper ores. The non-selective flotation step uses collectors and conditions, such as pH, that are conducive to the strong flotation of sulfide minerals generally. In the oxidative leach, the copper sulfide minerals in the concentrate fraction are oxidized to copper compounds, which are soluble in the leach solution. The oxidative leach includes the use of ammonia and sulfite under agitation leaching conditions to convert the copper sulfide minerals into ammonia soluble forms.

Abstract: A process for cleaning recycled pulp includes an upright cylindrical vessel having an upright cylindrical screen member open at its top and bottom ends and having a perforated screen wall which is centered on a vertical axis in the vessel. A plurality of upright, elongated blades are mounted for rotation on the vertical axis in close proximity to the screen wall. A pulp slurry entrained with pressurized air is introduced under pressure into an inlet in the bottom of the vessel. The rotating blades clear the screen wall while creating a rising vortex of air bubbles produced by the pressurized air for carrying ink and/or contaminant particles upwardly through the inner volume of the screen member. An "accepts" outlet at the center of the vessel draws off pulp in suspension that has been passed through the screen wall. A "rejects" outlet at the top of the vessel draws off ink and contaminant particles carried by the air bubbles in the upwardly-moving vortex.

Abstract: A froth crowder device is disclosed for incorporation into a froth flotation cell to improve the froth removal dynamics of the flotation cell. The froth crowder device is positioned within a froth flotation cell above and below the overflow launder, and provides a sloped surface to direct froth toward the overflow launder in an expedited manner. Experimental data confirms that use of a froth crowder device as disclosed expedites movement of the froth toward the launder for more efficient operation, permits operating the rotor of the flotation cell at reduced speeds without compromising the efficiency of operation, and reduces the amount of air necessary to produce a froth in the cell. Experimental data also confirms that little or no surface eddies are observed in froth flotation cells in which a crowder device as disclosed is used.

Abstract: The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Abstract: The invention provides for flotation equipment which is locatable inside a container for a pulp to be subjected to a flotation process and a rotor or impeller or agitator rotatable within the container about a substantially vertical axis, the rotor including first means for imparting a radially upward pulp stream movement to pulp particles in the container, the first means being in the form of a set of arcuate surfaces located between the vanes and second means for moving air from atmosphere in a downward direction to below the pulp stream level in the container, the second means comprising a set of arcuate surfaces extending from the top of the rotor to outlets in the peripheral surfaces of the vanes.

Abstract: An apparatus for cleaning recycled pulp includes an upright cylindrical vessel having an upright cylindrical screen member open at its top and bottom ends and having a perforated screen wall which is centered on a vertical axis in the vessel. A plurality of upright, elongated blades are mounted for rotation on the vertical axis in close proximity to the screen wall. A pulp slurry entrained with pressurized air is introduced under pressure into an inlet in the bottom of the vessel. The rotating blades clear the screen wall while creating a rising vortex of air bubbles produced by the pressurized air for carrying ink and/or contaminant particles upwardly through the inner volume of the screen member. An "accepts" outlet at the center of the vessel draws off pulp in suspension that has been passed through the screen wall. A "rejects" outlet at the top of the vessel draws off ink and contaminant particles carried by the air bubbles in the upwardly-moving vortex.

Abstract: The present invention concerns a reactor for removing impurities from a liquid, in particular for de-inking, including a tank (1) within which the liquid to be purified together with a gas or air is introduced (2-3); a drain of the purified accepted through an outlet (7) of said tank (1); inlets (8-11, 9-12, 10-13) at different heights of the tank (1) connected to said purified liquid outlet (7) together with the inlet of gas or air; a rotating shaft (18) inside the tank (1) carrying blades (20, 21, 22, 23) at the different heights of the tank within which the liquid together with gas or air is introduced; the blades (20, 21, 22, 23) have progressively increasing heights when moving towards the lower portion of the tank (1). The invention also concerns the method embodied by the above-described reactor.

Abstract: Method and apparatus for the separation of particles from a particulate suspension. The apparatus comprises a rotating flotation drum (10) with a feed distribution chamber (13). Particulate suspension feed enters the chamber through a delivery pipe (20). The feed passes through holes (21) into the particle collection chamber (22). Air is passed into the particulate suspension through a porous inner wall (29) and a froth is generated. The froth and particulate suspension pass into a froth cleaning chamber (32). The froth is washed by being sprayed from a washwater distribution pipe (47). Froth is removed from the drum by a froth scraper (49) through a froth removal chute (50). Unfrothed particulate suspension passes through openings (40) into a weir chamber (41) and is removed through a launder (45).

Abstract: A flotation device (1) which includes a tank (2) to contain a slurry (3) incorporating minerals which are to be extracted. Aeration of the slurry (3) by suitable structure in the device produces a zone (11) of mineralised froth above the slurry (3). A launder (15) directs the mineralised froth away from the tank (2). At least one porous diffusion surface (16) in direct contact with the froth dispenses a washing liquid directly into the froth zone (11).

Abstract: A flotation apparatus has an array of flotation cells which are in serial fluid flow communication from a first to a last cell. Each cell is in overflow communication with an overflow froth receiving receptacle which preferably has a top lip of slightly varying height in each cell. Air inlet and mechanical agitation are provided for each cell and are so positioned to promote an upright circular fluid flow in each cell toward the froth receiving receptacle. Each cell has internal surfaces shaped and oriented to promote the upright circular fluid flow and to discourage the creation of reverse eddy currents within the cell.

Abstract: The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Abstract: The present invention concerns a reactor for removing impurities from a liquid, in particular for de-inking, including a tank (1) within which the liquid to be purified together with a gas or air is introduced (2-3); a drain of the purified accepted through an outlet (7) of said tank (1); inlets (8-11, 9-12, 10-13) at different heights of the tank (1) connected to said purified liquid outlet (7) together with the inlet of gas or air; a rotating shaft (18) inside the tank (1) carrying blades (20, 21, 22, 23) at the different heights of the tank within which the liquid together with gas or air is introduced.; the blades (20, 21, 22, 23) have progressively increasing heights when moving towards the lower portion of the tank (1). The invention also concerns the method embodied by the above-described reactor.

Abstract: A method of removing fine contaminants from waste paper fibrous material (S) is described with solution (1) and pre cleaning (2) whereupon the fibrous material is first subjected to a washing treatment (3) and then to a flotation treatment (5). The washing filtrate (12) from the washing treatment (3) is cleaned in a filtrate-flotation treatment (4) so that a cleaned fraction (14) can be returned into the useful material (13) of the washing treatment. The so cleaned waste paper fibrous material can be passed to further treatment steps such as flotation, bleaching and/or dispersion. The reject material from the filtrate-flotation (4) is, in one embodiment, again subjected to a flotation treatment.

Abstract: Components, usually but not exclusively gaseous components, are removed in a liquid medium from gas streams and chemically converted into an insoluble phase or physically removed. Specifically, hydrogen sulfide may be removed from gas streams by oxidation in aqueous chelated transition metal solution in a modified agitated flotation cell. The same principle may be employed with other procedures in which a gaseous phase is dispersed in a liquid phase to effect an interaction between components present in such phases. A gas-liquid contact apparatus, generally a combined chemical reactor and solid product separation device, comprising such modified agitated flotation cell also is described. In order to effect efficient mass transfer and rapid reaction, gas bubbles containing hydrogen sulfide and oxygen are formed by rotating an impeller at a blade tip velocity of at least about 350 in/sec. to achieve the required shear.

Abstract: A flotation device for the separation of nonmiscible liquids, particularly the separation of water and hydrocarbon pollutants, comprising a cylindrical tank divided by partitions into a feed flow rate homogenization compartment, at least one flotation cell equipped with a cyclone-turbine and a skimming chamber with self-stabilizing chute, and a tranquilization compartment, characterized in that said cyclone-turbine is equipped with a throttling disk and vortex stabilization baffles, and that the skimming chute is equipped with lateral floats and counterweights.

Abstract: A method of separating desired material from undesired material is provided. The method is performed by forming a slurry of material and introducing it into a specially designed flotation reactor chamber. A foam is generated and introduced into the reactor chamber and dispersed into the slurry. A stream of water is provided to separate the undesired portion of the material from the desired portion of the material that has adhered to the bubbles in the foam.

Abstract: A floatation separation method is described for separating pieces of fruit or vegetable of the same type, but wherein desirable pieces have a slightly different specific gravity from the undesirable ones, and all have a specific gravity about the same as that of water. The pieces (12, FIG. 3 ) are placed near the surface of a body of water, and a cloud (40) of tiny air bubbles is maintained in the water. As the bubbles float to the surface they encounter the articles and slightly increase their buoyancy. The increase in buoyancy is slight and uniform, so those articles having a density slightly greater than that of the water will remain at the water surface, while those of a slightly greater density cannot be floated by the air bubbles and will sink to the bottom. The cloud of air bubbles is created by allowing air at about atmospheric pressure, to emerge from apertures in a rapidly spinning rotor that open in a direction primarily opposite to the spin direction.

Abstract: The invention relates to a flotation column including a plurality of controlled recycle chambers intentionally introduced into the column to cause the non-float fraction or gangue to drop down in the main float stream while the desired float fraction travels in the opposite direction by recycling to continually mix the pulp while coursing through the column. Recycle zones are positioned on the periphery of the main passage or flotation zone within chambers located in series along the column. A portion of the slurry is drawn into a recycle zone where it passes downwardly to return to the flotation zone or the main passage through the column to again be swept through the column.

Abstract: A flotation apparatus for floating minerals from fluid containing minerals in particulate form. The flotation apparatus includes a hydraulic motor directly connected to a drive shaft for driving a rotor located in the flotation cell, the hydraulic motor being powered by a hydraulic power pack having dual gear pumps to circulate hydraulic fluid at pressures of up to 2900 psi to drive the hydraulic motor. The dual gear pumps include a smaller gear pump for developing high pressure at low flow for quick, soft start of the flotation apparatus. Once started, the larger pump automatically takes over to provide high flow at lower pressure to develop rotor speed of approximately 160 RPM.

Abstract: A method for treating liquid waste water sludge after its generation and separation from the waste liquid involves forcibly impacting sludge particles and microbial cells against a contact surface to thereby fragment the particles into smaller-sized particles and break apart the organic cells. As a result of such a fragmentation process, water located in the pores of the sludge particles is released, thereby enhancing a subsequent dewatering process performed on the sludge. The destruction of the cells permits a subsequent solids digestion process to work more efficiently, while also permitting a more complete conversion to dissolved sugars, proteins and carbon dioxide.

Abstract: A foam flotation reactor for the separation of hydrophobic and hydrophilic products is provided. The reactor combines a material to be beneficiated, collector reagents, and a stream of specifically generated gas bubbles, in order to collect the desired product in the foam in a more efficient manner. A narrowed upper part of the reactor and accompanying water sprays force separation of undesired particles. A foam generator efficiently supplies a bubbly liquid/frothing agent to the reactor.

Abstract: The invention relates to a flotation machine for flotating minerals from slurries containing these particles, the said flotation machine comprising a flotation cell and a mixer mechanism provided in the cell, an element for introducing air into the cell and an element for feeding the material to be flotated into the cell and for removing it therefrom. According to the invention, in the slurry chamber (2, 18) of the flotation machine, essentially below the foam bed (4, 21) created in the flotation machine, there is arranged at least one guide member (3, 19, 32), so that the free area of the flotation machine, essentially at least in the slurry chamber (2, 18) below the foam bed (4, 21) can be reduced when proceeding upwards.

Abstract: The froth flotation apparatus includes a gas bubble-particle contact unit including a mixing structure for breaking a gas into fine bubbles,such as a packed tower packing or mechanical agitator, and a separate phase separation unit. A conditioned aqueous pulp containing a mixture of hydrophobic and hydrophilic particles and a substantially inert gas, such as air, are introduced into and combined in one end of the contact unit and subsequently flow concurrently through the mixing structure, such that the gas is broken into fine bubbles which intimately contact and become attached to the hydrophobic particles. The resulting gas bubble-particle mixture is introduced into the phase separation unit which is operated under substantially quiescent conditions. A concentrate fraction containing primarily hydrophobic particles and a tailing containing primarily hydrophilic particles are discharged from the upper and lower portions of the phase separation unit, respectively.

Abstract: The invention relates to an apparatus for feeding air into a flotation cell provided with a rotor and a stator. According to the present invention, air is fed into the intermediate space formed in between the rotor and stator covers, to above the rotor, wherefrom the air is distributed symmetrically.

Abstract: A wastewater flotation separation system is provided, which operates effectively with a minimum of maintenance. The apparatus includes a container (12) for holding wastewater, an inlet (14) located at a lower portion of the container, and an aerator (24) adjacent to the inlet for generating air bubbles that cling to waste particles to bring them to the water surface. A skimming apparatus (30) which skims particles off the surface of the wastewater into a sludge receiver (44) includes a beach device (42) with an inclined upper surface (40), and a belt device (34) that moves a series of scrapers (32) along the surface of the water and along the beach device into the sludge discharge. Each scraper includes a flap of resilient material which is bent as it scrapes along the inclined beach surface.

Abstract: A method and apparatus for fragmenting waste water sludge particles to destroy sludge particles and to enhance a dewatering process performed on the sludge. Sludge is passed through a slotted rotor that centrifugally propels the sludge through slots in a surrounding annular stator. Sludge particles forcibly impact against the side surfaces of the stator slots to fragment into smaller sized particles. During the fragmentation process water located in the pores of the sludge particles is released. The free water can later be separated from the sludge in a dewatering apparatus. When passing through the rotor and stator slots, organic cells are broken apart and a portion of each is converted to dissolved sugars and proteins.

Abstract: A foam flotation reactor for the separation of hydrophobic and hydrophilic products is provided. The reactor combines a material to be beneficiated, collector reagents, and a stream of specifically generated gas bubbles, in order to collect the desired product in the foam in a more efficient manner. A narrowed upper part of the reactor and accompanying water sprays force separation of undesired particles. A foam generator efficiently supplies a bubbly liquid/frothing agent to the reactor.

Abstract: The present invention relates to a method for concentrating a certain mineral fraction attached to air bubbles from a slurry to the foam layer accumulated on the surface, so that the concentration takes place in three different mixing zones. The apparatus of the invention is formed of a colon-like flotation arrangement and of flow guides, a flow attenuator and an agitator belonging thereto. The flotation reactions are created in the bottom zone, wherefrom air bubbles and mineral particles carried by them are directed in a controlled fashion onto the surface of the apparatus. The flotation apparatus is so designed, that a strong agitation in the bottom zone can be used without causing harmful separation of the foam in the bottom part of the apparatus.

Abstract: The invention relates to an improved flotation cell design for the mining industry. The flotation cell includes a cylindrical froth flotation unit and a unique hexagonal overflow froth launder. The unique design optimizes the froth flotation process and allows for the economical utilization of a honeycomb nesting arrangement.