Abstract: An arrangement in grading and cleaning machines with a screen (15). The screen is associated with at least one sensor (24) in the flow of material passing through the screen for generating electric signals in dependence on material particles leaving the screen as throughput and impinging on the sensor. The sensor is operatively connected to be adjusted (26) through a function circuit (25) for the control of various operations parameters of the screen (15) in dependence on the impingement intensity to achieve a throughput according to a predetermined mathematical model.

Abstract: A method for separating components of a mixture containing particles which can be electrically charged from particles which can be only negligibly charged is disclosed. The mixture is fed onto an electric undulating traveling wave contact panel which is energized to a charging potential using A. C. voltage. The voltage is then increased to a separation voltage to effect levitation and movement of the charged particles away from the uncharged particles. Separation is accomplished by cycling the voltage between the separation and charging voltages until the charged particles are moved off the panel and the uncharged particles remain on the surface of the panel. The separated particles can then be collected separately.

Abstract: The separation of different types of particulate matter in a carrier liquid is obtained by using an ultrasonic standing wave and relying on the different acoustic responses of the different particle types. By varying the acoustic energy propagation cyclically a more effective separation rate can be obtained, with a more readily attracted particle type being subjected to a further discrimination step in each cycle. The cyclical energy variation may be in the intensity of the standing wave, e.g. using suppression means, and/or the velocity of the standing wave relative to the liquid medium, e.g. using phase control means.

Abstract: Sedimentation field flow fractionation apparatus having a rotor-mounted fractionation column, has detectors positioned to observe the fluids from the column while still in the rotor. Designs include parallel reference and fractionation columns having their outflows compared in a rotor-mounted fluid flow density balance. Optionally weired channel columns provide a free fluid surface for more efficient resolution. Horizontal rotational axes are preferred. Rotor-mounted fluid flow density balances are also provided which are suitable for detecting liquid density changes in the other applications, such as liquid chromatography.

Abstract: A magnetohydrostatic centrifuge of unique geometry in which an elongated separation space is provided within the bore of an elongate cylindrically shaped multipolar magnet. Separations are accomplished both with and without rotation by passing particles to be separated through the separation space within a paramagnetic or ferromagnetic fluid. Certain separations are preferably made using a quadrupolar magnet configuration with a paramagnetic fluid, others with a quadrupolar magnet and a ferromagnetic fluid, and still others, with a sextupolar magnet and a ferromagnetic fluid. Efficient use is made of the magnetic field through the use of a plurality of inner ducts creating a plurality of thin, elongate separation channels characterized by long particle dwell time and short drift distances during the separation process. Significant throughput capacity is achieved in a system in which the magnetic medium is pumped through the separator.

Abstract: The present invention comprises a method of recovering copper minerals from ores containing both sulfide and oxidized copper sulfide minerals, such as found, for example, in surface oxidized porphyry ores. Accordingly, one embodiment of the present invention comprises first conditioning a pulp of an ore containing copper sulfide and oxidized copper sulfide minerals in the presence of an alkaline agent, next subjecting the so conditioned ore to a second conditioning step in the presence of a collector, subsequently adding a surface modifying agent to the so treated ore at a rate and in an amount sufficient to decrease the platinum electrode potential of the pulp when measured against a saturated calomel electrode to a minimum of -100 mV, then conditioning the ore only for a time sufficient to achieve intimate contact between the ore particles, and thereafter subjecting the so treated ore to conventional flotation.

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: A method of controlling the separation of coal from a mixture of coal and refuse in a froth flotation device by measuring the differential back pressure between two gas bubbler tubes immersed to different depths into the body of pulp in the device to produce a first control signal representative of the pulp density, and adjusting the rate of addition of a froth enhancement additive to the froth flotation device responsive to changes in said first signal; a second signal, produced by measuring back pressure of a single bubbler tube and representative of the pulp level in said device, can be corrected for changes in density by combining it with said first signal and then utilized to control liquid level in the cell by adjusting the rate of withdrawal of refuse therefrom.

Abstract: A method of separating the components contained in agricultural by-products is disclosed. A set of parallel electrodes encased in a plastic panel and energized by an A.C. power supply is used to create an undulating traveling wave electric field. A voltage charge is first applied to the individual components. The voltage is then increased to effect levitation and movement of the components in opposite directions which results in separation. The voltage is cycled between charging and separating voltages to move the components over a distance for collection and recovery.

Abstract: This invention is directed to a method of beneficiating a material, such as coal, by subjecting the coal to be treated to the action of a dense-media cyclone, where the dense-media thereof is a slurry of magnetite in water. More particularly, the present invention relates to a method to control the separating gravity of said cyclone within predetermined limits by (1) measuring the flow rate and percent magnetite in the flow discharging from the cyclone, and (2) based on pre-calibrated data, adjusting the feed flow and content, i.e. magnetite and/or water, into said cyclone, thereby controlling said separating gravity within predetermined limits.

Abstract: A method for separating solid phase from drilling mud, comprising forming from drilling mud and adhesive layer on a rotary closed curvilinear surface partly placed in the drilling mud, with subsequent feeding of an ionized gas jet along a tangent line to the adhesive layer, the gas jet entraining and removing solid phase particles from the drilling mud. The linear velocity of the adhesive layer in the zone of its contact with the gas jet is controlled by changing the velocity of the gas jet.

Abstract: Method and device of separating materials of different density by ferromagnetic liquid, using the separation zone formed by a set of magnets disposed so as to form a V-shaped gutter with both of the pole faces thereof. Objects to be separate are moved crosswise to the gutter by forming the separation zone extending in the range of the opening portion of the V-shaped gutter in such a manner that the separation zone is sloping in a plane across the gutter. This permits separation of materials of larger size in comparison with prior methods. The device is suitable for separating materials having larger size such as scraps of automobile containing aluminum and its alloys having a relatively large size and adapted to be separated from other heavy materials such as copper, zinc and their alloys.

Abstract: A method for determining the efficiency of float-sink raw material separation units which achieve separation by specific gravity sorting of raw material in particle form introduced to a liquid bath. The efficiency is determined by introducing to the bath, with the raw material in particle form for separation, prepared particles of determined size and specific gravity and detecting the separation location of these prepared particles.

Abstract: An inclined static deoiler and conditioner for treating ore such as coal, phosphate, and the like which combines with liquid to form a slurry prior to froth floation which includes in combination a trough having plural baffles therein which are oriented to cause turbulence in the slurry. End walls on the trough are provided having an inlet and outlet adapted to fasten to piping in which the maximum flow rate is determined by the piping diameter such that liquid entering in the trough is assured of staying substantially at or below the vertical height of the baffles. The through flow within the device is controlled by angulation of the trough which is variable, and baffle configuration.

Abstract: In an infeed housing for a harvesting and threshing machine there is provided an improved infeed housing design that redirects the flow of crop material along its predetermined path of travel at a selectively creatable discontinuity in the floor of the infeed housing to ensure the ejection of stones and other non-frangible objects subsequent to their detection and prior to their reaching the threshing and separating apparatus of the combine.

Abstract: A vibratory apparatus for use in association with a vacuum casting apparatus wherein the box containing the sand and casting upon completion of the vacuum casting is moved on track means to a vibrating station where it is lifted off the track, tilted, and vibrated to discharge the sand and separate the sand from the casting.

Abstract: The method described is useful in field flow fractionation techniques for reducing separation times and improving the convenience and accuracy of measuring sizes or molecular weights of particulates. In field flow fractionation, the particulates (particles or macromolecules) are subjected to a force field and a mobile phase while passing through a flow channel. This field strength is decreased exponentially as a function of time. Alternatively the flow velocity is increased exponentially as a function of time. The initiation of the change in field strength or flow velocity may be delayed a period of time. If this time delay is made equal to the time constant of the exponential decay, the range of particulate retention time that is linearly related to the logarithm of the particle size or molecular weight is increased.An apparatus for implementing the method is also described and teaches the use of a function generator for providing the desired exponential decay and delay time.

Abstract: Colloidal particles are fractionated by size and dissolved polymers are fractionated by molecular weight by passing a polar solvent dispersion containing one or both through a bed of surface-bonded particles wherein the particles consist of a nonswellable inert core with a polar solvent-swellable surface coating of bonded organic polymer. The core can be either an insoluble cross-linked organic polymer gel or an inorganic solid such as silica or alumina.

Abstract: An apparatus and method for separating components of a fluid mixture of materials uses an acoustic or sonic generator attached to one end of a hollow tube, or column having a uniform internal diameter, to produce standing sonic waves within the column. The sonic waves act as so-called chromatographic plates with the plate height being equivalent to the wavelength, and the plate number in the column being equal to the total number of nodes in the column. The effective column length can be controlled by the use of moving sonic waves which by changing the direction of wave motion can enhance or attentuate the separation process to produce a variation in the apparent column length without changing the physical length of the ultrasonic column. A sample to be separated and a carrier fluid are introduced into the end of the column adjacent to the sonic generator while a fluid exit is provided in the other end of the column.

Abstract: The invention concerns a method for optimization of the coal slurry dewatering process. Through a regulation of the fine grain content, it is possible to keep the filter cake at a constant level and thus to maximize the dewatering process. A separation of the slurry into a predominantly relatively fine grain fraction and a relatively coarse grain fraction, with the division point being between about 0.03 and 0.15 mm, is carried out, with a formation of a coal agglomerate from the fine grain fraction, and a dehydration of both the coarse grain fraction and the coal agglomerate from the fine grain fraction.

Abstract: A method and apparatus for continuous, steric field-flow fractionation and segregation of particles according to particle size. An elongate, fluid flow channel carrying a stream of entrained particles is subjected to a force field which urges the particles against one of the channel walls. The field strength is sufficient and in an appropriate direction to maintain the particles in close proximity to the wall so that particle size determines the rate of movement down the channel, the larger particles being exposed to the higher flow rates toward the center of the flow stream. The combined effects of fluid flow forces and force field strength develops a pattern of selective particle deflection from a point of particle infusion near the top of the channel, such that the particles drift and settle into segregated groups of common particle size.

Abstract: Particulate glass values contained in a comminuted inorganic fraction are recovered by froth flotation in a substantially sulfate ion free aqueous flotation medium and an amine as the beneficiation reagent.

Abstract: A silicic acid filter cake and suspension agent are fed to a container equipped with a stirrer having a peripheral speed of about 20-30 m/sec. The ratio of container diameter to stirrer diameter is about 3:1. The ratio of container diameter to level of filling is a maximum of about 1:2. The container contains at least about 1.5 to about 2 kg of silicic acid suspension, for each 1 kg of silicic acid filter cake which is added to the container. The contents of the container is mixed while maintaining a pH of at most about 4. A portion of the resulting silicic acid suspension is drawn off from the zone of highest turbulence in the container. An apparatus for carrying out the process is provided.

Abstract: Apparatus for cleaning objects, especially root crops such as sugar beet, comprises first and second members defining first and second surfaces respectively arranged for cleaning objects by relative movement between the surfaces and the objects to be cleaned. The first and second surfaces are arranged to converge towards each other over at least a part of the extent of each surface and are preferably in generally cylindrical form. Driving means drive the first member in a reciprocatory movement such that the first surface moves towards and away from the region of convergence of the surfaces, and drive the second members in a motion such as to effect at least an average movement of the second surface towards the region of convergence of the surfaces. Preferably the first and second members are rotary members positioned generally side by side with the axes of rotation thereof substantially parallel.

Abstract: A steric field-flow fractionation system including a flow channel adapted for use with a carrier stream of fluid having particles suspended therein and a force field disposed across the flow channel to cause migration of the particles to a restraining wall, thereby forming layers of particles at the restraining wall. The strength of the force field is adjusted sufficiently high to maintain the particles of a given class at the restraining wall such that particle distance from the wall is a function of steric hindrance. Particle displacement by flow along the channel is thereby determined by particle size, permitting fractionation of the particles based on differential migration of the various sizes of particle classes.

Abstract: A process for magnetically separating non-magnetic material from a mixture by combining the mixture with a magnetizing solution containing the salt of a magnetic element. The magnetic atoms attach to available sites on the molecules of the non-magnetic material so as to develop in that material a positive susceptibility. Thus the material is responsive to the influence of a magnetic field to move the material to a region where it can be analyzed or recovered. Materials with low positive or negative susceptibilities are separated by suspending them in a magnetic salt solution which when subjected to the attraction of a magnetic field develops a differential buoyancy force, pushing the diamagnetic or weak paramagnetic material strongly away from the magnet. Disclosed are solutions of ferric chloride, manganese chloride, erbium chloride, dysprosium chloride, terbium chloride, and holmium chloride.

Abstract: The method for separating particles having mixed density and/or size, comprises dispersing the particles in a fluid stream, passing the fluid stream into a housing which causes the fluid stream to be diverted from its original direction, and capturing certain of the particles within the housing which deflect the least amount in response to the directional diversion of the fluid stream. Apparatus for accomplishing this method include a channel in which the air flow undergoes a change in direction of 90.degree., one boundary being a right angle bend and the other being formed from a circular curve or rectangular hyperbola. Another device for accomplishing the method includes an inlet channel which enlarges in diameter and which includes capturing means placed along the longitudinal axis of the inlet channel, whereby the fluid must divert radially outwardly around the capturing means as it passes from the inlet channel through the enlarged portion thereof.

Abstract: In transporting solid material of a wide particle size distribution ranging from small to large size particles, a liquid is added to the solid material as a transporting medium to convert the solid material into a slurry to be hydraulically transported. The slurry that has performed the function of transporting the solid material is passed through a water removing device and a solid-liquid separating device to produce a suspension which is stored in a heavy medium tank and returned, after adjusting the concentration of the solid material therein, to the starting point of transportation so that the suspension can be recycled for use as a heavy transporting medium.

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: An apparatus for separating non-magnetic materials of different densities, which apparatus includes a material separating portion, in which a magnetic fluid is retained in a magnetic field having a gradient in a vertical direction. In this apparatus, a single conveyor is jointly used for the supply, and charging of materials to be separated, into the material separating portion, and the transporting of floating materials of a low density through the magnetic fluid and their recovery outside.

Abstract: An improved trash separation mechanism at the rear cross-conveyor assembly of a tomato harvester. A frame of the harvester supports a centrally located fruit collecting conveyor for delivering fruit rearwardly to the rear cross-conveyor assembly. A blower directs a strong rearward airstream from adjacently below the rear end of the collecting conveyor across the rear cross-conveyor assembly. A rearwardly rotating roller is mounted adjacently behind the cross-conveyor assembly and moves vegetative and mineral trash away from the cross-conveyor. A slide plate behind the roller may deflect the trash to the ground. A series of resilient fingers depending downwardly from above the roller move in circular vertical patterns to agitate the trash as it collects at the roller to prevent accumulation of the trash upon the roller and to enhance rearward movement thereof upon the roller and deposit of the trash on the ground.

Abstract: A silicic acid filter cake and suspension agent are fed to a container equipped with a stirrer having a peripheral speed of about 20-30 m/sec. The ratio of container diameter to stirrer diameter is about 3:1. The ratio of container diameter to level of filling is at most about 1:2. The container contains at least about 1.5 to about 2 kg of silicic acid suspension, for each 1 kg of silicic acid filter cake which is added to the container. The contents of the container is mixed while maintaining a pH of at most about 4. A portion of the resulting silicic acid suspension is drawn off from the zone of highest turbulence in the container.

Abstract: Particles of different densities are separated from admixture by ferrohydrodynamic movement in a liquid magnetic medium into zones thereof and retained in said zones upon solidification of said liquid medium.

Abstract: Particles suspended in a fluid medium are separated into isolated fractions by size by passing a suspension of such particles through an unobstructed passageway, the particles emerging from the passageway in decreasing order of size.

Abstract: Separation of a mixture of non-magnetic particles on the basis of their different densities is accomplished by levitation in a magnetic fluid using a multiplicity of magnetic gaps created by a grid of magnetic poles oriented with respect to each other such that the polarity of the magnetic field generated in each gap is opposite to that of each adjacent gap.

Abstract: Sieving apparatus comprising a sieve carrier, means for imparting longitudinal vibratory movement to the sieve carrier said movement having substantially no vertical component, a sieving medium, a sieve frame to which said sieving medium is secured and supporting said sieving medium at an inclination of not more than 5.degree. to the horizontal, resilient means interposed between the sieve frame and the sieve carrier to support said sieve frame in said sieve carrier, an ultrasonic generator mounted on said sieve carrier and separate from said means for imparting vibratory motion, and coupling means coupling the output from said ultrasonic generator to said sieve frame, in a direction substantially parallel to the plane of the sieving medium.

Abstract: This invention is directed to a scheme for increasing the height of a ferrofluid column in a ferrofluid sink/float separator by judiciously locating the access openings into the column of ferrofluid so that said opening is on a predetermined air-ferrofluid interface to support a specific height of a ferrofluid column.

Abstract: Sieve analysis and fineness modulus of particles are adjusted in bulk, without breakdown into size fractions and reblending to tailor a feed product for a given application such as asphalt sand or concrete sand by adjusting the rate of largest size cut and smallest size cut removal in a way to modify the distribution of intermediate fractions.

Abstract: Apparatus employing an ultrasonic focusing transducer is provided for removing a contaminant such as oil which is floating on the surface of a body of water. The transducer is supported beneath the water surface with its focal region aimed at the underside of the contaminant oil. A source of alternating current is connected to the transducer to generate ultrasonic waves which travel through the water and converge at the focal region. The apparatus includes a collecting arrangement which catches most of the oil bounced upwardly as the result of the focused ultrasonic waves before that upwardly discharged oil can fall back onto the water surface.The method of using such an apparatus.

Abstract: Superparamagnetic wax compositions useful in magnetic levitation separations of particle mixture based on density differences are provided which have the ability to withstand without phase separation repeated melt-freeze cycling. The stability is obtained by using a mixture of hydrocarbon and oxygenated waxes.

Abstract: Hollow microspheres having thin and very uniform wall thickness are useful as containers for the deuterium and tritium gas mixture used as a fuel in laser fusion targets. Hollow microspheres are commercially available; however, in commercial lots only a very small number meet the rigid requirements for use in laser fusion targets. Those meeting these requirements may be separated from the unsuitable ones by subjecting the commercial lot to size and density separations and then by subjecting those hollow microspheres thus separated to an external pressurization at which those which are aspherical or which have nonuniform walls are broken and separating the sound hollow microspheres from the broken ones.

Abstract: A desirable metal such as gold in a low grade ore has its concentration increased by electro-kinetically separating gangue from other components in the ore to form a concentrate. Separation is effected by inducing movement of externally conductive particles upwardly and radially outwardly over the walls of a container enclosing a dielectric liquid within which the ore is initially contained. An electric field is established for this purpose between the container walls and an electrode positioned above the surface of the dielectric liquid.

Abstract: A method of separating non-magnetic particles of different densities by using a ferrofluid to produce levitation wherein compensation is made for the magnetic attraction or interaction of the particles by removing particles too small for the desired sharpness of separation or by maintaining the ratio of the interaction force to the separation force outside of theoretical limits.

Abstract: A method of separating small diameter non-magnetic particles of different densities by using a low magnetic saturation ferrofluid and a high magnetic gradient to produce levitation by overcoming the magnetic attraction of the particles.Application of a constant gradient field of a level below the magnetic saturation level of the ferrofluid forms the ferrofluid into a density gradient column. Each non-magnetic particle levitates to the level inside the ferrofluid having the same apparent density as the particle.The ferrofluid contains magnetic particles with a mean effective core diameter less than about 50 angstroms and a stabilizing agent layer on the particle exceeding about 50 angstroms. Perfluorinated carriers and surfactants are preferred for their relatively high intrinsic density.