Abstract: The invention relates to a multiple liquid injector composed of several identical elementary injection tubes 2, disposed in a rim around a central tube. Each tube 2 has an inlet conduit 3, itself comprising a converging truncated cone 6 and a cylinder 7, followed by an aeration zone 4 comprising an aeration chamber 8 fed tangentially by a conduit 9 perpendicular to the tubes 2, a jet centering funnel 10, followed by mixing cylinder 11, and lastly a diverging outlet conduit 12.

Abstract: Ring injectors for aerating fluids, useful for example in flotation systems, have a housing with a mixing section, in which air is added to the through-flowing fluid through an annular slot. A core is arranged in the center of the mixing section. An air-solid mix is formed in the mixing section by deposition of air bubbles on solid particles. An annular injector with a slot width (Q.sub.2) that leads into the airing chamber with a minimum opacifying speed of 2.0 m/s at the inlet of the aerating chamber, has an annex mixing and dispersing section (6) with a cross-section that remains the same until the end (12), as well as a middle piece (10) centrally arranged therein also having a constant cross-section, the length of the mixing and dispersing section (6) being 20 times the width of the annular slot (Q.sub.3). The distributing cone (2) and the middle piece (10) can be screwed together or inserted into each other. The air slot can be regulated by spacing rings (13).

Abstract: The present invention is directed to air sparged hydrocyclone flotation apparatus and methods for separating particles from particulate suspensions (such as coal and mineral ore slurries), wherein fluid discharge is removed annularly from a flotation vessel. Preferably, the flotation apparatus includes a vertically oriented cylindrical flotation vessel having a tangential inlet at its upper end and an annular outlet at its lower end. The annular outlet allows for the smooth exit of fluid discharge from the flotation vessel so as to avoid disturbance of the fluid flow within the flotation vessel. Air is sparged into the vessel and a froth which contains the recovery products exits through a vortex finder positioned in the upper end of the vessel. The apparatus includes a froth pedestal positioned within the vessel which forms the annular outlet with the wall of the vessel. The froth pedestal may take a generally cylindrical or a generally conical configuration.

Abstract: Apparatus for controlling the flow of a foam uses a bellow enclosed in a housing. The bellows is filled with foam under pressure from a foam generator and expands a preselected amount at which point the flow of foam into the bellows is interrupted. Simultaneously with the interrupting of the flow of foam into the bellows, air under pressure is routed into the housing which causes the bellows to collapse forcing the foam out of the bellows. The apparatus is particularly useful in the froth flotation (benefication) of minerals.

Abstract: The disclosure herein describes a method for the separation of hydrophobic from hydrophilic materials in a liquid suspension by means of gas bubbles and a flow of water that drags the hydrophobic material upwards. A distinctive feature of the method is an upward flow of water countercurrent to the flow of settling hydrophilic particles. The disclosure describes a cell in which gas is caused to disperse into an ascending flow of liquid and in which a feed port is provided to introduce particles in a flow countercurrent to that of the bubbles and water.

Abstract: Apparatus for treating water by gaseous diffusion and flotation comprising a single reactor which is separated into at least two compartments. One compartment is used for gas transfer with a pressurized gas diffuser flushed by a liquid current wherein water to be treated is introduced downwardly. The other compartment is in communication with the first compartment by means of an orifice whose opening diameter and orientation are controlled.

Abstract: An arrangement for separation by flocculation of flocculable substances contained in a suspension, as such is used particularly for purifying the backwater of deinking installations for waste paper processing, comprises a container supplied by a conduit with a suspension coming from a reservoir and admixed with flocculating agents and with air. The container contains a rotor with vertical shaft from which two arms extend outwardly at different heights. The suspension to be purified is delivered by the shaft and the upper arm, and by means of the lower situated arm leading the upper arm at an acute angle the purified water is removed. The floated-up flocculated substances are withdrawn from the surface as flotation scum and optionally by means of a conveying device through a scum conduit.

Abstract: This invention relates to a grit trap which is intended for use in removing grit from a flow of sewage. The grit trap is of the kind which includes a settlement chamber which has an inlet through which the flow of sewage can flow and an outlet from which treated sewage can flow. There is also provided a grit storage chamber which is disposed between the settlement chamber and in which in use the separated grit will collect, the settlement chamber having a mixing device for promoting a desired motion to the flow of sewage entering the settlement chamber. In accordance with the invention said mixing device comprises a disc 25 which is provided with a plurality of generally radially extending blades, said disc being located just above the upper end of the grit storage chamber.

Abstract: An apparatus and method for generating gaseous bubbles in a liquid body comprises a bubble chamber for mixing a pressurized gas with a liquid at a pressure greater than atmospheric and a fine injector tip for releasing the pressurized gas-liquid mixture from the bubble chamber under a high tip velocity and shear. The apparatus is adapted for supplying bubbles to a flotation column for the treatment of mineral ore materials.

Abstract: A device for suspending solid particles in a turbulent fluid for the purpose of concentrating particles of interest such as mineral particles comprises an upright column provided with a plurality of impellers spaced along a rotatable shaft extending centrally within the column. An inlet is provided near the bottom of the column to introduce compressed gas which is dispersed by the rotating impellers to create a rising column of bubbles through a slurry of particles in a liquid so that a gas to liquid gradient is provided along the column. Disks are spaced along the shaft between the impellers, and baffles are provided longitudinally at the inner surface of the column to control the swirling of the fluid caused by the impellers.

Abstract: Wastepaper is treated by a ink-removing process in which an aqueous wastepaper pulp slurry is introduced into a treating vessel, air is blown into the wastepaper pulp slurry preferably through a number of air-blowing orifices formed on a peripheral surface of at least one horizontal cylinder located in the bottom portion of the vessel to absorb ink particles floating in the wastepaper pulp slurry by air bubbles ejected from the orifices and rising toward the wastepaper pulp slurry surface. The resultant ink-absorbed froth is then removed. In this process, air is blown in an amount satisfying the relationship (I)G/L.gtoreq.5.0 (I)wherein L is the volume (m.sup.3) of the wastepaper pulp slurry in the treating vessel and G is the total volume (Nm.sup.3) of the air bubbles blown into the vessel, to promote the contact of the air bubbles with the ink particles in the wastepaper pulp slurry.

Abstract: Flotation apparatus and methods for separating particles from particulate suspensions such as coal and mineral ore slurries, wherein fluid discharge is removed annularly from a flotation vessel. Preferably, the flotation apparatus includes a vertically oriented, cylindrical flotation vessel having a tangential inlet at its upper end and an annular outlet at its lower end. The annular outlet allows for the smooth exit of fluid discharge from the flotation vessel so as to avoid disturbance of the fluid flow within the flotation vessel. The apparatus includes a froth pedestal positioned within the lower end of the vessel which forms the annular outlet with the wall of the vessel. The froth pedestal further serves to support a froth column formed within the flotation vessel and isolates the froth column from the fluid discharge so as to minimize mixing therebetween.

Abstract: The instant invention comprises a method and apparatus for providing an alternative to chemical precipitation, electroplating and hydroxide floculation and for improving the separation of heavy metal from water.

Abstract: A flotation device provided with a raw water tank; a flotation tank thereto the flowing of raw water from said raw water tank is generated by a water level differential; a stirring apparatus for air mixing located at flowing passage of raw water flows from said raw water tank to said flotation tank; a chemicals supply apparatus adding the cationic polymer coagulant at the upper stream side and the anionic polymer coagulant at the lower stream side of said stirring apparatus of said flowing passage; a gas supply apparatus feeding air with lowering the upper stream side of flowing passage at just before upper stream side of said stirring apparatus of said flowing passage.

Abstract: The instant invention provides a method and apparatus to improve the treatment capacity in the flotation process and to reduce the cost of equipment improving the dehydration of the separated scum using only natural dehydration and air-dry that have no need of mechanical dehydration process.

Abstract: A method for improving separation of the flotable phase from the non-flotable phase of a slurry of particulate material in a froth flotation machine comprising a tank, an upper outlet port for discharge of the flotable phase, and a mechanism for delivering air to the slurry in the tank to form a froth which includes a mixture of air bubbles and the flotable phase from the slurry, with the rate and selectivity of separation of the flotable phase from the slurry for predetermined size particles of the flotable phase and at a predetermined concentration of the flotable phase being dependent on the total volume and size distribution of the air bubbles generated in the slurry, the method of this invention comprising the steps of providing a quantity of slurry in the tank, generating air bubbles of relatively small size and relatively large size, and controlling the volume of air as small bubbles and the volume of air as large bubbles in response to the concentration of the flotable phase of the slurry for enhanced

Abstract: A froth flotation system for separating a mineral fraction from an aqueous pulp containing a mixture of mineral and gangue particles. The aqueous pulp is supplied to a pulp-filled vessel (or column) wherein a froth is formed on the surface of the pulp and collected in a launder. Gas bubbles are introduced into the pulp in the vessel by two different means to generate the froth. In accordance with one means, water is aspirated into a stream of pressurized gas (air) to form a stream of aerated water which is injected into the lower portion of the pulp-filled vessel. In accordance, the other means, a second stream of pressurized gas (air), is sparged through a porous wall of one or more micro-diffusers located within the vessel. The dual means for generating bubbles produces a significantly higher level of mineral separation than can be achieved from either means separately.

Abstract: A flotation cell featuring a mixing pipe which enters the suspension essentially vertically, follows the point of air intake, and generally receives the entire suspension quantity per flotation cell, the injector of the flotation cell is offset sideways relative to the vertical center axis of the round container cross-section and away from the side on which the foam removal opening and the liquid drain opening are located. The mixing pipe (1) enters the suspension only for a distance such that its discharge opening, mouth (2), is located at least at one-half the height of the level of the overflow edge (7) of the foam removal channel (8), figured from the container bottom. The liquid drain opening (9) is preferably provided in the immediate vicinity of the container bottom, with a cover plate (11) extending across the length of the flotation cell and forming a drain channel (12) into which proceeds the clean liquid through an upper (14) and a lower (13) slot.

Abstract: In deinking, the flotation of fiber suspensions is performed in a cylindrical tank 2 to which the fiber suspension is fed through a coupling means 36 as primary stream. The fiber suspension is already aerated and is withdrawn through a suction connection 33 below the coupling means 36 and fed after another aeration through a secondary connection 35 above the coupling means. The volume of the circulated secondary stream is greater than the volume of the primary stream. It is thereby assured that the fiber suspension is aerated at least twice and thus better cleaned.

Abstract: The aeration of dispersions, especially the aeration of fiber suspensions in a flotation apparatus 1, is performed with a ring injector 2 to which air is delivered through air feed ducts 11 in the mixing section 4. The annular gap forming in the ring injector 2 is thus aerated inside and out. The center core 7, which tapers in the direction of the greatest free cross section Q4 of the ring injector 2, is provided with a fin 56 which prevents the rotation of the dispersion.

Abstract: Apparatus for the mixing of gas bubbles into fiber suspensions in order to remove impurities from the fiber suspension by means of flotation is disclosed, including an inlet, an outlet including diverging upper and lower walls, an intermediate mixing section including upper and lower wall surfaces and a wing suspended between them in order to create upper and lower passages in the intermediate mixing section, the wing including an initial diverging portion, a central portion and a subsequent converging portion so that the central portion has a maximum thickness corresponding to the minimum transverse dimension for the upper and lower passages, the converging portion of the wing corresponding with the diverging upper and lower wall portions of the outlet so that the upper and lower passages diverge substantially symmetrically in the direction of flow, and an aperture for injecting a gas such as air at a location corresponding to the central portion of the wing.

Abstract: An improved method and apparatus for froth flotation separation of the components of a slurry, having particular utility for the beneficiation of coal by the flotation separation of coal particles from impurities associated therewith, such as ash and sulfur. In this arrangement, an improved open flow, spiral nozzle is positioned above a flotation tank having a bath therein, and sprays an input slurry through an aeration zone into the surface of the water. The spraying operation creates a froth on the water surface in which a substantial quantity of particulate matter floats, while other components of the slurry sink into the water bath. A skimming arrangement skims the froth from the water surface as a cleaned or beneficiated product.

Abstract: The present invention provides an apparatus for generating gas bubbles in a liquid. The bubbles, which are uniform in size and on the order of approximately 100 micrometers in diameter or less, enhance the efficiency of gas transfer to the liquid. The apparatus includes at least one rotatable member, in the shape of a disc or ring, which is wettable by the liquid and rotatable therein at an edge velocity of at least 70 feet per second. The upper surface of the rotatable member is parallel to, and spaced from, a stationary plate to form a shear zone. Gas, or some other fluid, is supplied proximate the upper surface of the rotatable circular member to form the bubbles. Optimized relationships between the radius of the disc or ring and its speed of rotation are disclosed to enhance the efficiency of operation of the apparatus.

Abstract: The invention relates to the concentration and beneficiation of particulate matter by froth flotation and in particular to improvements in hydraulic-pneumatic flotation apparatus which contribute to the efficiency of operation. Such apparatus employs a constriction plate which separates vertically arranged flotation and hydraulic compartments. A discharge duct may be used to extend through the hydraulic compartment and to open through the constriction plate centrally thereof. Orifices in both the constriction plate are in communication with the hydraulic compartment to provide a uniform dispersion of air bubbles in the flotation compartment. Aerated water distribution manifolds within the hydraulic compartment and within the lower portion of the flotation compartment are provided to enter the aerated water into the flotation compartment substantially uniformly throughout a horizontal cross-section thereof.

Abstract: The invention relates to a flotation machine designed for floating minerals from sludges containing coarse particles. The flotation machine comprises a rotor (3) and a stator (2) provided with actuator machinery and auxiliary equipment (7, 8, 9). The bottom (14) of the stator (2) is solid and the stator-rotor mechanism is located within the cell apart from the cell bottom (10). The feed inlet pipe (12) is connected to the cell so that the feed is directed towards the mixing zone of the rotor flow.

Abstract: The flotation apparatus comprising a container having a free liquid level of the fiber stock suspension which is fed essentially horizontally to the container by at least one infeed device. The infeed device contains at least one aeration element having an outlet cross-section located at a predetermined region which is 100 to 600 mm, preferably 50 to 250 mm, below the liquid level of the fiber stock suspension in the container. Between the end of the aeration element and the discharge mouth or opening of the infeed device which opens into the container there can be arranged an essentially horizontally extending starting path for quieting or stabilizing the flow of the fiber stock suspension. This starting path is provided at its initial region with an ascending cover member at which merges a channel having a free liquid level.

Abstract: Improvements in flotation separating systems of the type employing small rising air bubbles to induce ascension of certain types of particles in a flotation compartment while other particle types descend toward the bottom of the compartment include a bubble passing, particle blocking barrier forming the bottom of the compartment separating the compartment from a source of air bubbles while allowing the introduction of a uniform distribution of air bubbles into the compartment in the form of a gently sloped conical plate having a plurality of aerated water passing apertures and an array of downwardly extending pocket forming baffles for limiting bubble migration along the slope of the lower plate surface. The baffles are generally configured as radially and circumferentially extending baffle portions.

Abstract: An improved froth flotation installation for separating solid particles from an aqueous slurry by delivering a stream of the aqueous slurry directly into a vortex chamber along with a supply of bubble-forming gas. The kinetic energy of the slurry creates necessary froth bubbles, and provides mechanical agitation of the contents of a froth flotation separation zone upon discharge from the bottom of the vortex chamber. In multi-zone froth flotation installations, the direction of flow of the aqueous slurry of unrecovered solid particles is deliberately changed at least twice between a first froth flotation zone and a last froth flotation zone to improve solids-froth contact and to minimize the possibility of particles adopting a short circuit path through the installation. Multiple froth flotation zones are serviced by a single slurry pump in a preferred embodiment.

Abstract: An improved froth flotation installation for separating solid particles from an aqueous slurry by delivering a stream of the aqueous slurry directly into a vortex chamber along with a supply of bubble-forming gas. The kinetic energy of the slurry creates necessary froth bubbles, and provides mechanical agitation of the contents of a froth flotation separation zone upon discharge from the bottom of the vortex chamber. In multi-zone froth flotation installations, the direction of flow of the aqueous slurry of unrecovered solid particles is deliberately changed at least twice between a first froth flotation zone and a last froth flotation zone to improve solids-froth contact and to minimize the possibility of particles adopting a short circuit path through the installation. Multiple froth flotation zones are serviced by a single slurry pump in a preferred embodiment.

Abstract: The invention relates to a repeating flotation machine for floating minerals from sludges. The repeating flotation machine comprises a flotation cell (1) and a repeat flotation cell (16) placed therein. Inside each cell there is placed a mixer apparatus composed of a stator-rotor combination (2, 3; 17, 18).

Abstract: A vortex chamber aerator is provided with a split feed conduit whereby the liquid feed is introduced into the vortex chamber through two opposed passageways to provide more even distribution of the liquid currents within the vortex chamber. This results in reduced wear in the vortex chamber and more importantly presents a uniform discharge pattern of the liquid and entrained gas bubbles.

Abstract: An improved method and apparatus for froth flotation separation of the components of a slurry, having particular utility for the beneficiation of coal by the flotation separation of coal particles from impurities associated therewith, such as ash and sulfur. In this arrangement, a forward product stream is formed in which a mixture of the particulate matter slurry and the chemical reagents is sprayed through a nozzle at a first relatively low pressure onto the surface of water in a forward stream flotation tank to create a floating froth phase containing therein a first quantity of the particulate matter. The remainder of the particulate matter slurry separates from the froth phase by sinking in the water, and the froth phase is separated as a first product.

Abstract: The froth flotation device includes a flotation column partially filled with a packing which defines a large number of small flow passages extending in a circuitous pattern between the upper and lower portions of the column. A conditioned aqueous pulp of a mineral ore, such as iron ore, is introduced into the midzone of the column. A pressurized inert gas, such as air, is introduced into the bottom of the column and is forced upwardly through the flow passages in the packing. As the air flows upwardly through these flow passages, it is broken into fine bubbles which intimately contact the floatable particles (e.g., iron oxide) in the aqueous pulp and forms a froth concentrate or float fraction which overflows from the top of the column. Wash water is introduced into the top of the column and flows through the flow passages in the packing countercurrently to the float fraction to scrub entrained non-floatable particles (e.g., gangue) from the froth concentrate.

Abstract: A screening device for immersion in a vessel containing a pulp or slurry, said device comprising a screening chamber having at least one side wall defined by a screen and closed at the top and bottom said screen being located to be immersed in the pulp or slurry, a discharge pipe located within the screening chamber having an open lower end and positioned close to the bottom and an upper end opening into a discharge outlet external to said vessel said discharge outlet being located below the surface level of the pulp or slurry and above the level of the bottom of the chamber, the capacity of the discharge outlet being such as to maintain a flow rate through the screening chamber and discharge pipe to maintain the solids in the pulp or slurry passing through the screening device in suspension.

Abstract: The flotation apparatus has a vessel or container into which vortex or turbulence channels lead. These vortex channels supply the fiber suspension or stock to the vessel and are provided with at least one stepped enlargement. An air conduit supplying flotation air opens into the vortex channel. The vessel is substantially cylindrical about a vertical axis and is provided in its upper region with a central conduit or pipe for extracting the flotation foam. In the lower region of the vessel a conduit for extracting the recovered good stock is disposed tangentially.

Abstract: In a froth flotation beneficiation, the rate of addition of collector reagent is varied in response to the change in particle size effected by the beneficiation, as determined by comparing a size analysis of solid particles in one of the separated streams with a size analysis of solid particles in the feed stream.

Abstract: In a microbubble injector usable to separate materials of different density by flotation, a deflector wall deflects radially a flow of water exiting under pressure from an injector hole and containing dissolved air at the saturation concentration. This procures cavitation which is localized at the edges of the hole and which generates the required microbubbles of air downflow thereof.

Abstract: A method for directing a desired amount of gas below the liquid surface in a solution reactor, to mix the bubbles as effectively as possible with a suspension of a pulverous solid and a liquid, and to produce in the mixed gas-liquid-solid suspension a strong, suspension-maintaining flow field which is downward in the center of the reactor and upward along its sides, is disclosed. A so-called gls-mixer according to the invention consists of a circular plate fitted at the lower end of a rotating shaft suspended by its upper end, vertical dispersion blades situated radially at the edges of the circular plate, and baffles attached to the dispersion blades by means of arms. An upwardly directed gas-feeding conduit is fitted at the bottom of the reactor, and from this conduit the gas jet discharges to the center point of the circular plate.

Abstract: A method and apparatus for deinking a fibre stock or slurry. In order to optimize the separation process the invention proposes to independently control the air injection phase, the mixing phase, and the separation phase by splitting them into separate steps.Thus, there is provided a separation cell which is fed with slurry from an inlet. Air is introduced into the slurry before entry into the separation cell and before entering a mixing section which mixes the air and slurry before entering the separation cell. The air is introduced under pressure by way of a porous sintered sleeve, while the mixing is achieved by the provision of three turbulence discs in the preferred embodiment. Alternative turbulent generating means may be employed.The mixing ensures contact of the ink with the air bubbles which separate out in the separation cell and rise to the surface as a foam. The foam is removed by suction, while the deinked fibre slurry is drawn off from the tank by means of a weir or stand pipe.

Abstract: A fluid diffuser for dispersing a gas or liquid into a body of receiving liquid in which it is immersed. The diffuser includes a rotatable shaft, a thin disk-like member mounted for rotation on the shaft, and an annular ring positioned adjacent the outer perimeter of the disk-like member. At least one of the top and bottom walls of the annular ring is porous. These top and bottom walls define a fluid plenum, into which gas or liquid under pressure is introduced to be emitted from the plenum as small, nascent fluid spheroids on the surface of the annular ring. The boundary layer flow from rotation of the disk-like member within the body of receiving liquid shears fine gas bubbles or liquid particles from the foraminous surface or surfaces of the annular ring. The annular ring may be fixed, or rotatable in the opposite annular direction from the rotation of the disk. Impeller blades may be mounted on the top and/or bottom surfaces of the rotatable disk.

Abstract: An improved method and apparatus for froth flotation separation of the components of a slurry, having particular utility for the beneficiation of coal by the flotation separation of coal particles from impurities associated therewith, such as ash and sulfur. In this arrangement, an improved open flow, spiral nozzle is positioned above a flotation tank having a bath therein, and sprays an input slurry through an aeration zone into the surface of the water. The spraying operation creates a froth on the water surface in which a substantial quantity of particulate matter floats, while other components of the slurry sink into the water bath. A skimming arrangement skims the froth from the water surface as a cleaned or beneficiated product.

Abstract: A device for dispersing a second phase in a first phase is provided, wherein gas inlet means are arranged at the bottom of a vessel. The outlet parts of these inlet elements have a varying distance to the bottom, this distance decreasing towards the center of the bottom. The distance of the outer outlet parts of the elements to the bottom, for those located near to the periphery, is from 15 to 40% of the diameter of the bottom.

Abstract: A method for concentrating ores of non-ferrous metals by flotation, wherein a pulp and air mixture is prepared and fed through a nozzle under pressure to the bottom part of a mixing chamber. The mixture is directed toward an impact wall in such a manner that after the jet hits against the wall air bubbles of a diameter not exceeding 150-200 .mu.m are formed. The flows resulting from the impact against this wall are directed toward each other in such a manner as to collide in the top part of the mixing chamber at a velocity maximum 90-100 cm/s and at an angle 40-75.degree. with respect to the vertical axis of the mixing chamber, the resultant flow being deaerated, and a resultant froth layer removed. A flotation machine has a mixing chamber having a nozzle for feeding thereto a pulp and air mixture and an impact wall disposed directly adjacent to the nozzle, the mixing chamber having walls which are so shaped as to provide for carrying out the abovedescribed method.

Abstract: An apparatus for introducing gas into a liquid mass, particularly at a certain depth therein, includes at least one emulsifying tube adapted to be positioned within the liquid mass and to be vertically aligned above a gas port. The tube has at a lower portion thereof structure for receiving therein gas from the gas port and liquid from the liquid mass, such that the gas and liquid form an emulsion flowing upwardly through the tube. The tube has at an upper portion thereof, structure opening downwardly into the liquid mass for reversing the flow of the emulsion and for then discharging the emulsion downwardly into the liquid mass. Such reversing and discharging structure may be the form of a bend in the upper end of the tube or in the form of a hood mounted above and confronting the upper open end of the tube.

Abstract: An elutriation apparatus which combines pressurized liquid jets and the low energy air bubble flotation for the separation is described. A manifolded set of multiple apparatus which increases operator efficiency is described. Quantitative separation of roots is achieved by the apparatus by a closed system of mechanical separations using water and air to isolate and deposit roots on a sieve submerged in the water. The method provides a rapid, quantitative and inexpensive method for measuring plant root responses to soil biological, chemical, and physical conditions.

Abstract: A method is proposed for processing high-ash coal sludges by flotation of a slurry in the cells of flotation units, particularly for processing gas coal and open burning coal which are difficult to float, in which the coal slurry to be processed flows through the cells of the flotation unit pre-conditioned and controllably, particularly with control of the dwell time. In a preferred embodiment, the control of the dwell time occurs by a controlled distribution of the slurry to cells of the flotation unit which operate in parallel. For the purpose of controlling the dwell time of the slurry in a flotation unit, cells which are traversed in parallel are additionally connected or disconnected as a function of operating parameters, such as slurry density or solids content or solids distribution.

Abstract: The injector apparatus is of the kind having a constriction which lies, in the flow direction, immediately before a following adjoining mixing section, in which fibrous stock suspension is mixed with air for the purpose of subjecting the suspension to flotation in a flotation tank. The mixing pipe in which the mixing section is disposed has a radial diffusor at its outlet end, and, for a greater flow rate of air, additional air intake bores are disposed therein a short distance in the flow direction after the constriction.A favorable arrangement is achieved if the injector apparatus with the mixing pipe is arranged perpendicularly in a flotation tank, which may have the form of a reclining cylinder. In this case, the froth, like the cleaned suspension, is drawn off on one long side, i.e., a side which extends parallel to the cylinder axis; the extraction opening for the cleaned suspension being provided preferably immediately below the level of the suspension and/or the froth extraction arrangement.

Abstract: A non-diluting flotation apparatus and process is disclosed which includes a single cell, or a series of multiple cells. Each cell comprises a non-agitated, flotation vessel having a submerged inlet in its upper portion for feeding a previously treated or conditioned clay or ore suspension in water. The suspension flows downward in the vessel to an outlet from which a combined product and recycle stream is taken. Thereafter, a recycle stream is separated and air bubbles are entrained into the recycle stream which is returned to the lower portion of the cell. In the cell the entrained air rises as very small bubbles, flushing certain mineral impurities removed from the clay with the air. The air and impurities form a froth atop the liquid surface and the froth is mechanically removed.

Abstract: A method and system are provided for separating low and high density particles from a mixture thereof. A foam is continuously generated and carried on the outer surface of a horizontal drum. The mixture of particles is deposited on top of the foam surface near the apex of the drum so that the dense particles fall through the foam while the less dense particles are supported on the upper surface of the foam. A first blade is provided to shear the upper surface of the foam and remove the less dense particles. A second blade engages the surface of the drum downstream from the first blade to remove the relatively dense particles. The system finds particular use in separating raisins (dense particles) from waste materials associated with raisins (less dense particles).

Abstract: Mineral impurities can be effectively removed from coal by introducing oil droplets into an aqueous slurry of pulverized coal. Coal, which is lipophilic, attaches to the surface of the oil droplets and floats upwardly along with the oil droplets utilizing their buoyancy. On the other hand, mineral impurities, which are hydrophilic, are left in the aqueous slurry.