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: 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: 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: 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: A method of improving the quality of froth removed from a minerals separation flotation cell by providing converging side walls to crowd the froth into a narrower chimney and thereby increase the froth height. The riser is constructed so that the height of the froth from the pulp/froth interface to the froth overflow weir is greater than the natural froth height in a similar parallel-sided flotation cell.

Abstract: An apparatus for froth flotation separation of the components of a slurry, said apparatus comprising at least one flotation cell, at least one spray nozzle for feeding slurry to said flotation cell, and a rotatably mounted skimmer means for skimming froth from said flotation cell, wherein said spray nozzle is affixed to and situated behind the rotational direction of said skimmer means and wherein said spray nozzle and skimmer are adapted to simultaneously rotate thereby causing the skimmer to skim the froth in the direction opposite to the spraying direction of the spray nozzle.

Abstract: The method of the present invention is a novel comprehensive process for maximizing the recovery of valuable mineral values from coal ash. Options may also be included for the production of saleable inorganic chemical by-products. The process employs both physical and chemical extraction techniques that maximize the yield of products while reducing the quantity of waste produced. Valuable minerals and chemicals such as cenospheres (hollow microspheres), carbon, magnetite (Fe.sub.3 O.sub.4), alumina (Al.sub.2 O.sub.3), iron oxide (Fe.sub.2 O.sub.3) and iron chloride (FeCl.sub.3) may be produced. Due to removal of carbon, magnetite, and iron oxide from the coal ash, the processed ash comprises a quality pozzolan.

Abstract: Phosphatic clay dispersions are modified by dispersing the phosphate matrix containing the clay in a dilute solution of selected acids prior to screening, sizing and other beneficiation operations.

Abstract: A process for separating porous components from non-porous components of a mixture of granular materials comprising the steps of:(a) contacting the mixture of the porous and non-porous materials with a gas capable of adsorbing in the pores of the porous component;(b) discharging the so charged or loaded mixture into a liquid in which the adsorbed gas is allowed to desorb from the porous componet, the viscosity and surface tension of the liquid being chosen so that the desorbed gas remains attached to the porous component with the specific gravity of the liquid chosen to separate the so desorbed porous component from the nonporous component; and(c) separating the floating materials from those of sinking materials in the liquid of Step (b).

Abstract: Dimercaptodihydroxy alkanes are used as a curing agent for epoxide resins and as ore flotation agents.

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: A method for de-ashing crushed coal and transporting it in the form of pellets, said method comprising the following steps:A. the step of mixing pulverized coal with a binder to cover the surfaces of coal particles with the binder;B. the step of adding water to the pulverized coal;C. the step of stirring the slurry to disperse ash particles in the pulverized coal into water and to agglomerate coal particles in the pulverized coal by tumbling, whereby forming pelletized coal; andD. the step of separating the pelletized coal from the ash particles, and transporting the pelletized coal.The above basic four steps may be combined with the following steps depending on the state and particle size of raw coal:E. the step of crushing raw coal and separating it into high-ash coal and purified crushed coal, and further pulverizing the purified crushed coal and supplying the resulting powder to the above step A; andF.

Abstract: A method for removing ash, sulfur and inertinite from crushed coal includes float/sink treatment in aqueous solutions of monosaccharides, disaccharides, hydrogenated monosaccharides, hydrogenated disaccharides and mixtures thereof. Such solutions also improve the performance of such heavy media physical cleaning equipment as cyclones, heavy media baths, tables, spirals, hydroclones, flotation cells, jigs and solid-bowl centrifuges.

Abstract: Method of and apparatus for the flotation processing of minerals. The starting material is pretreated by means of flotation agents and is then spread in the form of a controllable thin film over a fixed perforated controllable-surface drum, the so-obtained suspension-film is blown through by an airstream from the inner to the outer side of said drum, and the stability or the composition of the frothed layer or of the unfrothed layer over the surface of the suspension is controlled.

Abstract: The process of separating minerals or metals from a crushed ore mixture of crushed ore, aqueous solution, and flotation agent by passing the mixture from an inlet through free fall into a container so entrapping air during the free fall and encouraging the development of a large quantity of froth, and an apparatus for separating minerals or metals from a crushed ore mixture consisting of a container and a mixture inlet situated above the container so that an air space exists between the inlet and the upper surface of the mixture in the container during operation.

Abstract: A gas-sparged hydrocyclone apparatus and method for achieving separation by flotation in a centrifugal field. The hydrocyclone apparatus is suitably modified so that a gas phase may be dispersed into the liquid vortex created in the hydrocyclone.

Abstract: A froth flotation apparatus for elimination of solid particle impurities contained within a liquid includes a vessel defining a flotation cell which includes an upstanding foam discharge conduit, an inlet conduit communicating with the vessel such that fluid flowing through the inlet conduit and into the vessel moves in a vortical fashion within the vessel, a skimmer, and a sparger. The skimmer consists of a generally cylindrical roller which is rotatably mounted between the discharge conduit and a side wall of the vessel and is buoyant so that it floats on the surface of the fluid within the vessel such that it is rotated by the vortical movement of the fluid within the vessel to prevent buildup of foam and maintain the motion of the fluid within the vessel. The sparger includes a substantially cylindrical porous element mounted on a tubular shaft which is rotatably mounted within the inlet conduit and driven by a motor.

Abstract: The disclosure concerns a method and apparatus for producing a suspension of fibrous material from waste-paper. Following dissolving the waste-paper, cleaning the dissolved suspension and stain removal, the suspension is floated in series of flotation cells. The suspension is first floated through a first series of flotation cells. Thinning liquid medium, such as water, is added to the suspension. It is then floated through a second series of flotation cells. In one embodiment, the cells of the second series are larger than the cells of the first series. Following the second series of cells, the material floated from the second cells is delivered to another cell. In another embodiment, the cells of the second series are themselves divided into two separate rows of cells and the suspension is divided among the rows of second cells. In this embodiment, following flotation through the second cells, the material floated from the second cells is next delivered to joint secondary cells.

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 primary spray nozzle is positioned above a flotation tank having a water 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 is floating, 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. Moreover, a recycling operation is provided wherein particulate materials which do not float after being sprayed through the primary spray nozzle are recycled to a further recycle spray nozzle to provide a second opportunity for recovery of the recycled particles.

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 spray nozzle is positioned above a flotation tank having a water 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 is floating, 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: An apparatus for mixing gas with liquid comprising:(a) an inner cylindrical member comprising an elongated tube having upper and lower ends and a plurality of turbines, which are free to rotate about their longitudinal axis, mounted within the tube, the turbines being spaced apart from one and another and so constructed that adjacent turbines have different rotational direction or velocity;(b) optionally, an outer cylindrical member comprising an elongated tube having upper and lower ends and a plurality of openings in the lower half of the tube wall;(c) a base member to which the lower ends of the outer and inner cylindrical members are attached so that the lower ends are sealed, the outer and inner cylindrical members being arranged in a concentric manner; and(d) a gas inlet pipe for introducing gas bubbles into the apparatus.The apparatus is useful for aerating sludge, separating the fine particles contained in a slurry, and separating particles having smooth surfaces from particles having jagged surfaces.

Abstract: A pulp suspension of waste paper which is laden with air bubbles is introduced into a flotation cell. Fine air bubbles rise through the pulp suspension toward the top. Printing ink and other impurities are deposited on the bubbles which form a foam layer on the surface of the pulp suspension. The foam which is laden with impurities is drawn off from the surface. The fibers which have been subjected to preliminary purification in this manner sink downwardly. For reducing the number of cells connected in series to fewer than a third, while obtaining the same degree of whiteness, the fibers which were subjected to preliminary purification are drawn off and are once again supplied to the flotation cell in the form of an air-laden pulp suspension. Alternatively, instead of the air-laden pulp suspension, a water-air suspension can be injected. The air bubbles which are thus introduced once again rise toward the top and traverse the sinking fibers in a counterflow.

Abstract: The solid organic materials contained in wet-process phosphoric acid are removed by froth flotation in a flotation cell in which the solid organic materials overflow with the foam from the top of the cell and the acid, after passing through the cell, is passed to extraction. The froth flotation process can also be used to remove defoamer and organic soluble materials from the wet-process phosphoric acid. Uranium in the partially purified phosphoric acid product is extracted with a suitable organic extractant, typically a mixture of mono- and di-(alkylphenyl) esters of orthophosphoric acid.

Abstract: A process for purifying an aqueous solution of NaOH by removing suspended NaCl and Na.sub.2 SO.sub.4 impurities therefrom comprising bubbling a gas into the impurity-containing NaOH solution at a temperature above 16.degree. C. and up to about 36.degree. C.

Abstract: A process for purifying an aqueous solution of NaOH by removing suspended NaCl and Na.sub.2 SO.sub.4 impurities therefrom comprising bubbling a gas into the impurity-containing NaOH solution at a first stage temperature above 16.degree. C. up to 31.degree. C. and at a second stage temperature above 31.degree. C. up to about 36.degree. C., separating a foam layer containing NaCl and Na.sub.2 SO.sub.4 from NaOH at the first stage and a foam layer containing Na.sub.2 SO.sub.4 from NaOH at the second stage.

Abstract: A process for reducing the sulfur and ash content of coal particles wherein coal particles are treated in an aqueous slurry with a minor amount of hydrocarbon oil to form coal-oil aggregates having modified particle size and density characteristics. The coal-oil aggregates are separated from ash and mineral matter in the slurry by gravitational means. Optionally, the coal particles may be treated with a conditioning agent prior to the aggregation step. Recovered coal particles comprise a substantial part of the feed carbon values.

Abstract: A process for reducing the sulfur and ash content of coal wherein coal particles are treated in an aqueous slurry with a minor amount of hydrocarbon oil to form coal-oil aggregates. The coal-oil aggregates are separated from ash and mineral matter in the slurry by dissolved gas flotation. Optionally, the coal particles may be treated with a conditioning agent prior to the aggregation step. Recovered coal particles comprise a substantial part of the feed carbon values.

Abstract: Coarse particles of up to 3 mm are floated in a cylindrical froth flotation cell in which the agitation impeller has a cover preventing fluid from being drawn in above. Air is supplied from a ring around the periphery of the cell and situated above the cover. Baffles project radially inwardly up to a short distance from the top. Froth is allowed to overflow around the periphery of the cell. The opposed inlet and outlet are disposed respectively below the level and at the level of the impeller. The arrangement is such that the liquid below the layer of froth is substantially quiescent.

Abstract: A method of producing bubbles for treating a suspension by flotation, wherein in which the suspension enriched with dissolved gas is caused to flow into a flotation vat via a pipe the flow in the pipe is rapidly interrupted at a predetermined frequency by a shutter unit which is suddenly closed and produces, in the downstream portion of the pipe, a periodic wave of low pressure such that cavitation bubbles are produced in the flow in said downstream portion, the low pressure wave propagating in the pipe up to the flotation vat where it is reflected as a wave of high pressure which produces the collapse of the cavitation bubbles and forms micro-bubbles which become fixed to the particles to be floated, the conditions in the pipe being such that the micro-bubbles are in a super-saturated medium in relation to the local pressure conditions and tend to be enlarged during their flow up to the flotation vat.

Abstract: Method and apparatus for separating ink from pulped inked paper: a suspension of pulped paper and chemicals enters a cylindrical container tangentially near the container bottom and rotates around the interior of the container; the ink and chemicals form a foam that floats off the suspension of paper fibers; the suspension exits from the container tangentially near the container top; a funnel at the top of the container; a foam outlet near the axis of the container from the funnel; a vortex generator at the bottom of the container, which blows upwardly creating a vortex in the suspension; means disperse air in the suspension in the container inlet before the suspension enters the container through the container inlet; the dispersing means either comprises a rotor cooperating with a stator, or comprises deflector plates in the container inlet; air is supplied to the inlet at the dispersion means rotor or deflector plates; the deflector plates may be washed clean.

Abstract: A method for separating a first liquid from a mixture with a second liquid or particulate solid by a series of froth flotation and froth separation stages is improved by recycling a portion of the mixture recovered upstream of the last flotation stage to an initial or an intermediate stage further upstream from the point where the recycled liquid is obtained.

Abstract: A mixing and aeration impeller is comprised of a hub and a plurality of first flutes interspaced between and joined to a plurality of second flutes. The flutes are adapted to the hub and have troughs which begin proximate the hub and extend radially away from and angularly downward and upward away from a plane normal to a shaft to which the impeller is adapted. The flutes are preferably formed as one unitary structure and shaped in a periodic pattern which may be generally sinusoidal or trapezoidal in cross section normal to the radius of the impeller along the length of the troughs. The impeller includes means to receive compressed air from a source and means to exhaust the compressed air radially outward from the rim. The hub has means to receive the compressed air and to communicate it to a passage or gap formed in the flutes to transmit the air radially outward to the rim. The air is exhausted through a slot along the rim of the impeller. A shroud with radial fins may be positioned about the impeller.

Abstract: Methods and apparatus for treating water/wastewater to remove grit, susped and colloidal solids of organic and inorganic nature, microorganisms and surfactants. Dense suspended solids (grit) are first removed by a centrifugation process. The influent water/wastewater is then passed through coagulation and flocculation chambers, an upflow clarifier and a high-rate settling chamber for final sedimentation. Next, the influent passes through a foam filter to remove colloidal particles. The water/wastewater under treatment is then pressurized and saturated with air and subsequently depressurized, causing the dissolved gas to bubble out of solution floating out suspended contaminants. At this point, ozone is introduced into the influent to create a thicker, more dense foam by oxidizing organic matter and for disinfection purposes. The foam floated to the surface of the influent is scraped off and furnishes the foam for the foam filter.

Abstract: A method and system of maintaining substantially steady state conditions in a froth flotation operation. In the method an aqueous pulp of finely ground ore particles continuously flows into a flotation cell and is continuously aerated by admission of air wherein aqueous pulp of flotation concentrates substantially continuously overflow from the cell. The novel and improved method step comprises continuously monitoring the mass flow of flotation concentrates from the cell and, accordingly, varying the admission of aeration air into the pulp in the cell inversely with respect to the variations in the mass flow of the overflow to achieve steady state conditions in the cell. The system contemplated for continuously maintaining a substantially steady state condition in a froth flotation operation includes at least one froth flotation cell into which flows an aqueous pulp of finely ground ore particles, and aeration means fluidically communicating with the flotation cell for delivering air thereto.

Abstract: A flotation process wherein hydraulic effects are used to disperse gas bubbles throughout a contained liquid body with a free surface. The process comprises ejecting a two-phase fluid into the liquid body with the density and the kinetic energy of the ejected fluid per unit of the contained volume being such as to define a point within the area encompassed by Regions I and II in the graph of FIG. 2.

Abstract: The carbon-wax coating is removed from carbon paper by sequentially immersing the coated paper in hot aqueous baths, the paper being squeeze-dried prior to immersion in each bath after the first. Ultrasonic vibrations are applied to the first bath to mutually separate the individual pieces of the paper.

Abstract: A method of effecting froth flotation in a receptacle divided by separating means to provide a plurality of flotation cells arranged one above another comprises passing froth upwardly from a first cell into a second cell situated thereabove while controlling the thickness of the froth layer in the first cell to correct variations therein and thereby inhibit coalescence. Apparatus for use in said method comprises a receptacle divided by separating means to provide a plurality of flotation cells arranged one above another, said separating means being adapted to provide, in operation, passage means for the passage of froth upwardly from a first cell into a second cell situated thereabove, the first cell having control means which acts to control the thickness of the froth layer in the cell in response to a variation in the thickness of said layer.

Abstract: Wastewater is treated by a method and an apparatus in which a wastewater flow passes through an electrocoagulation cell having rod-shaped electrodes longitudinally disposed therein. The electrodes are oriented in one or more circles or portions of circles. The wastewater flow remains within the cell for about 1/10 minute to 2 minutes, during which time pollutants within the wastewater are turbulently mixed and combined with bubbles produced at the electrodes, thereby forming an embryo floc. The embryo floc flows out of the cell with the treated wastewater from the top portion of the downstream end of the cell, after which it may be treated with a flocculant to form a full floc. The full floc and thus clarified wastewater flow into a flotation basin where the full floc undergoes a laminar flow to the top of the clarified wastewater and is skimmed off.

Abstract: An improved spray apparatus for the froth flotation of a liquid-solid slurry, e.g., water-containing coal particulate, is disclosed. The initially high velocity of a spray of the slurry prior to its contacting the surface of liquid in a froth flotation cell is significantly reduced through a double deflection arrangement associated with the spray nozzle. This reduction in the velocity of the spray results in a more efficient froth flotation process.