Abstract: A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

Abstract: Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

Abstract: An apparatus may include a separator and/or a discharger. A separator may include a separator channel, an influent portion configured to allow the passage of a first fluid into a separator channel, an effluent portion disposed above an influent portion and/or a fluid-lift portion between an influent portion and an effluent portion. A discharger may be disposed below a fluid-lift portion and/or may include a portion external to a separator channel, which may include a downward angle relative to an effluent portion and/or may be configured to minimize the passage of a second fluid into a discharger as the second fluid buoyantly travels in a separator channel from an influent portion to an effluent portion. A second fluid may have a density that is less than the density of a first and/or may be configured to lift a first fluid to a fluid-lift portion.

Abstract: A method of controlling operation of a froth flotation cell comprises introducing gas into a liquid in the cell, thereby to create a froth on the surface of the liquid, which froth overflows and leaves the cell at an overflow point, wherein the froth has a froth height from the level of the overflow point to the upper surface of the froth, measuring values of the froth height for two values of gas flow rate into the cell, measuring values the velocity at which the froth overflows at the overflow point for two values of gas flow rate into the cell, calculating a gas flow rate into the cell that optimises gas recovery, by treating the measured values of froth height and measured values of froth velocity independently, and setting the gas flow rate into the cell to be the calculated flow rate into the cell that optimises gas recovery.

Abstract: A method and apparatus in accordance with the present invention comprising a de-composable compound such as hydrogen peroxide as a primary additive to generate bubbles within a fluid medium such as an aqueous slurry of tar sands. The size range of bubbles, density (number per unit volume) of bubbles, and rate of in situ generations of bubbles are controlled by controlling process variables including but not limited to temperature, concentration of decomposable compound residence time, pressure, viscous shear, ratio of water to solids, pH of the slurry, shape of the separation vessel, and addition of one or more secondary process additives.

Abstract: A method and apparatus in accordance with the present invention comprising a decomposable compound such as hydrogen peroxide as a primary additive to generate bubbles within a fluid medium such as an aqueous slurry of tar sands. The size range of bubbles, density (number per unit volume) of bubbles, and rate of in situ generation of bubbles are controlled by controlling process variables including but not limited to temperature, concentration of decomposable compound, residence time, pressure, viscous shear, ratio of water to solids, pH of the slurry, shape of the separation vessel, and addition of one or more secondary process additives.

Abstract: A flotation separation apparatus for separating particles in suspensions, feeds slurry containing the particles through an inlet into a contactor where gas is fed through an inlet to mix with the slurry, for example in a downwardly plunging jet, to form a gas-liquid bubbly two-phase mixture under pressure from an outlet restriction in a throttling duct. The mixture is passed through a flow manipulator configured to induce a high energy dissipation rate, for example by way of a Shockwave formed in a diverging section of the throttling duct reducing the size of the bubbles and brining those bubbles into intimate contact with particles in the mixture which is released into a separation cell where a flow manipulating draft tube is provided to reduce turbulence in the mixture. Alternative apparatus and methods for inducing the high energy dissipation rate and for reducing turbulence in the mixture are also described and claimed.

Abstract: A system and method utilize model-based control of a froth flotation process for concentrating a desired target mineral from ground ore. The system and method exploit real time information about a surface tension of a pulp or flotation solution including the minerals. The surface tension represents exemplary additional information about the surface chemistry in the flotation process, and as such enables a refinement of a pulp model used in control of the flotation process. Ultimately, operational efficiency of a froth flotation plant is increased.

Abstract: A froth flotation method and apparatus for extracting a valuable substance from a slurry comprising a mixture of solid phase, liquid phase and said substance. A gas dispersing mechanism (4) feeds gas into the slurry (1) in a flotation vessel (2) to infuse gas bubbles into the slurry. The slurry is agitated in the flotation vessel (2) for dispersing the gas bubbles into the slurry. The gas bubbles capture the valuable substance from the slurry and form a froth phase F above the slurry phase S. The froth phase F exits the vessel by overflow. Continuously moving negative pressure zones (7) are mechanically generated by rake blades (9) in the froth phase (F). The negative pressure zones (7) extend from the froth phase (F) to the slurry phase (S).

Abstract: An apparatus and method capable of separating plastic films from garbage for collection is taking advantage of ductility of plastics, separation and extensibility properties of plastic films in water, and adhesion property of water to plastic films in order to provide a novel and unique garbage disposal implementation of rapidly, effectively, conveniently, and precisely separating medium-sized, light materials and plastic films from small garbage for collection and perform an initial cleaning of garbage by means of water while classifying garbage for facilitating a subsequent garbage disposal.

Abstract: A device and process for aerating dispersions, particularly for flotation of pulp suspensions, in a de-inking process. The process includes at least two stages, where each stage has a separate liquid circulating system which sucks in the gas or air and mixes it with the liquid. The device has at least two flotation cells, with each of the cells having a separate injector and a separate circulation system including a pump.

Abstract: The process is designed for the flotation of interfering materials from an aqueous fibrous pulp suspension and is in particular used in the processing of printed or used paper that is otherwise contaminated. The separation of gas bubbles of the suspension occurs in a flotation layer that has a maximum thickness of approximately 100 mm. The process also achieves good flotation results in fibrous pulp suspensions that have a fiber pulp content significantly larger than 1 % by weight, for example around 2% by weight. A flotation apparatus is provided for performing the flotation process. The apparatus includes a flotation vessel, an inlet, an outlet, and a skimmer device.

Abstract: The process targets the removal of interfering materials from an aqueous fibrous material suspension, especially if this is produced from recycled paper. Thereby interfering materials, such as printing ink particles, small synthetic particles, or sticky contamination, are eliminated by flotation in a particularly advantageous manner. In accordance with the invention, the combination of low-intensity and high-intensity flotation is undertaken, whereby the low-intensity flotation generally works in the gravitational field and the high-intensity flotation in a centrifugal field.

Abstract: A process for the extraction of precious metals from a copper sulphide ore or concentrate, by treating a leach residue of the ore or concentrate, includes the steps of removing elemental sulphur from the leach residue to obtain a low sulphur residue and subjecting the low sulphur residue to an oxidative leach at elevated temperature and pressure to oxidize sulphur and precious metal compounds present in the low sulphur residue to produce a residue for the extraction of the precious metals therefrom.

Abstract: A process for the extraction of a metal from an ore or concentrate comprises subjecting the ore or concentrate to pressure oxidation in the presence of oxygen and an acidic solution containing halogen ions and a source of bisulphate or sulphate ions, such as H.sub.2 SO.sub.4. The metals which can be extracted by the process comprises copper, as well as non-cuprous metals, such as zinc, and precious metals, such as gold and silver.

Abstract: A process for the extraction of zinc from a sulphide ore or concentrate containing copper and zinc includes subjecting the concentrate to pressure oxidation in the presence of oxygen and an acidic halide solution to obtain a resulting pressure oxidation slurry and subjecting the slurry to a liquid/solid separation step to produce a liquor containing copper and zinc in solution. The liquor containing the copper and zinc is subjected to a first solvent extraction with a copper extractant to remove copper from the solution and to produce a copper depleted raffinate. The copper depleted raffinate is subjected to a second solid extraction with a zinc extractant to produce a zinc depleted raffinate and the zinc depleted raffinate is recycled to the pressure oxidation step.

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: A process for separating a feed mixture of zirconium and petroleum coke containing traces amount of radioative materials by flotation process utilizing a plurality of flotation cells. The process comprises grinding the feed mixture, slurrying the ground feed mixture with water, treating the slurry with a flotation agent and a collector for the coke and subjecting the treated slurry to air sparging and agitation to create an overflow and an underflow. The overflow is then filtered to collect substantially zircon-free coke for further processing.

Abstract: A process of selectively agglomerating coal in an aqueous environment while leaving the mineral matter dispersed has been developed. This process is autogenous for hydrophobic particles in that neither an agglomerating agent nor an electrolytic coagulant is needed. It is based on the finding that hydrophobic particles are pushed against each other by the surrounding water structure. This process, which is referred to as selective hydrophobic coagulation, is driven by the so-called hydrophobic interaction energy, which is not included in the classical DLVO theory describing the stability of lyophobic suspensions. The relatively small coagula formed by the selective hydrophobic coagulation process can be readily separated from the dispersed mineral matter by several different techniques such as screening, elutriation, sedimentation and froth flotation.

Abstract: A wire guided float level measurement system includes a float, a nozzle and an ultrasonic level detector which are attachable to an open frame. The float, which is supportable on a froth, is slideably attached to te frame via one or more guide wires, and the nozzle and ultrasonic level detector are fixed near the top of the frame. In operation the frame, with attachments, is disposed in a flotation cell in an upright position so as to traverse a froth layer which is formed in the cell. The float, while supported by the froth so as to follow the froth level, serves as a target for pulses transmitted from the ultrasonic level detector, and the detector continually measures the distance to the float which is an indirect indication of froth level. Any mineral accumulation on the float, which would interfere with its buoyancy, is washed off the top of the float by spraying wash water through one or more nozzles.

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: 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: Low energy process for the production of gasoline-ethanol blends, comprising dehydrating the aqueous ethanolic product from a conventional fermentation process, preferably containing about 6 wt. % ethanol, so as to generate an aqueous ethanolic effluent containing about 90 wt. % ethanol; mixing the effluent with gasoline feedstock; chilling the resultant gasoline-aqueous ethanol mixture to a temperature of about -10.degree. F., without forming ice, thereby to form (1) a gasohol blend containing about 10 wt. % ethanol and (2) an aqueous stream comprising some ethanol and traces of gasoline; extracting the gasoline-containing aqueous stream with a minor stream of the fermentation ethanol product in order to recover the gasoline it contains; and recovering said blend to produce a gasohol product under-saturated with water at all operating temperatures above -10.degree. F.

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: Undigested matte particles in autoclave leach residues containing iron oxide are separated from iron oxide by subjecting an aqueous slurry thereof to flotation without the use of a flotation reagent by bubbling air therethrough to form a froth containing said undigested matte particles which is recycled for further leaching and provide an iron oxide-containing tails which is removed and discarded.

Abstract: In the flotation of oxide ores, a method of flotation characterized by applying d-c current to the oxide ore slurry as a pre-treatment prior to flotation.

Abstract: An aqueous solution of sodium hydroxide containing soluble impurities such as a concentrated catholyte produced by a diaphragm electrolysis is cooled by a coolant or a heat-exchanger to form a slurry containing sodium hydroxide hydrate crystals and fine impurity crystals. The fine impurity crystals are adsorbed on bubbles which are formed by vaporizing a dissolved coolant or introducing a gas in the slurry and separated from the slurry.