Stratifying Patents (Class 209/131)
  • Patent number: 9764332
    Abstract: An improved belt separator system and an improved method to separate particle mixtures based on triboelectric separation of particles is disclosed. One or more gas nozzles, for example, a plurality of gas nozzles are provided as part of the system or installed into a system, such as an existing system, to improve dispersal of particles during operation.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: September 19, 2017
    Assignee: SEPARATION TECHNOLOGIES LLC
    Inventors: Ted W. Bush, Kyle P. Flynn, Harry Vincent Leaf, Bulent Sert
  • Patent number: 8853583
    Abstract: A method for separating a granular synthetic material from a loose mass of various synthetic materials includes: conveying the granular mass along a trajectory having a rubbing surface subjecting the mass falling from the rubbing surface to an electrical field; and collecting at least one of the masses separated by the electrical field. The mass advances in a single layer on the rubbing surface, while maintaining the single layer contact with the rubbing surface, the rubbing surface being subjected to repeated acceleration in opposite directions in the plane of the rubbing surface, or tangential thereto to move the mass on the surface in order to improve the electrostatic charge. The rubbing surface is made of or clad with a material having intermediate triboelectric properties with respect to those of the granular mass, and is clad with a same material as that which it is intended to separate from the mass.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: October 7, 2014
    Inventor: Stefano Cassani
  • Publication number: 20110132812
    Abstract: Among other things, to cause directional motion of chiral objects in a mixture in a chamber, a field is rotated relative to a chamber to cause rotation of the chiral objects. The rotation of the objects causes them to move directionally based on their chirality.
    Type: Application
    Filed: February 16, 2011
    Publication date: June 9, 2011
    Inventors: Osman Kibar, Mirianas Chachisvilis, Eugene Tu
  • Patent number: 7931734
    Abstract: Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: April 26, 2011
    Assignee: Board of Regents of the Nevada System of Higher Education, on behalf of the Desert Research Institute
    Inventors: Hans Moosmüller, Rajan K. Chakrabarty, W. Patrick Arnott
  • Patent number: 7897044
    Abstract: The present invention relates to a fluidic separation device comprising: at least one microchannel (2; 66) extending along a longitudinal axis (X), the microchannel having a cross-section that presents a width measured along a first transverse axis (Y) and a thickness measured along a second transverse axis (Z) perpendicular to the first, the width being greater than the thickness, the microchannel including, along the second transverse axis, bottom and top walls (3 and 4); at least first, second, and third inlets (7, 8, and 9) in fluidic communication with the microchannel (2), the second inlet (8) being disposed on the second transverse axis (Z) between the first and third inlets (7 and 9); and at least first and third transverse separation walls (10 and 11) respectively separating the first and second inlets and the second and third inlets, the first and second separation walls (10; 11) being arranged in such a manner that the second inlet (8) is separated from each of said bottom and top walls (3 and 4
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: March 1, 2011
    Assignee: Centre National de la Recherche Scientifique
    Inventors: Mauricio Hoyos, Pascal Kurowski, Natacha Callens
  • Patent number: 7753211
    Abstract: The invention relates to a method of separating solid particles, using a magnetic fluid, wherein the magnetic fluid is passed through a magnetic field for the purpose of changing the effective density of the magnetic fluid, and the particles are separated into fractions of different density. The present invention further relates to device for separating solid particles, using a magnetic fluid.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: July 13, 2010
    Assignee: Bakker Holding Son B.V.
    Inventors: Peter C. Rem, Simon P. Berkhout, Erwin J. Bakker
  • Patent number: 7732725
    Abstract: A method of classifying fine particles includes: introducing a fine particle dispersion containing the fine particles to a micro flow channel having an inlet part and a collection part from the inlet part; moving the fine particles to an inner upper side of the micro flow channel by an electric field applied in a gravitational direction; and delivering the fine particle dispersion in a laminar flow state to the collection part. The delivering step includes classifying the fine particles according to differences in settling velocity among the fine particles.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: June 8, 2010
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Seiichi Takagi, Okimasa Okada, Tetsuo Ohta
  • Patent number: 7304258
    Abstract: A system for transporting and selectively sorting particles includes a first wall and a traveling wave grid extending along the first wall. The system includes a second wall having a passage extending therethrough and a gate operatively associated with the passage. A controller is adapted to output a multi-phase electrical signal. The controller is in communication with the traveling wave grid and the gate. A method of using the system is also provided.
    Type: Grant
    Filed: April 2, 2007
    Date of Patent: December 4, 2007
    Assignee: Xerox Corporation
    Inventors: Meng H. Lean, John J. Ricciardelli, Osman Todd Polatkan, Michael J. Savino, Eric Peeters, Scott Elrod
  • Patent number: 7217901
    Abstract: A system for transporting and selectively sorting particles includes a first wall and a traveling wave grid extending along the first wall. The system includes a second wall having a passage extending therethrough and a gate operatively associated with the passage. A controller is adapted to output a multi-phase electrical signal. The controller is in communication with the traveling wave grid and the gate. A method of using the system is also provided.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: May 15, 2007
    Assignee: Xerox Corporation
    Inventors: Meng H. Lean, John J. Ricciardelli, Osman Todd Polatkan, Michael J. Savino, Eric Peeters, Scott Elrod
  • Patent number: 7119298
    Abstract: An electrostatic separation apparatus for conductive particles and insulating particles with reduced separation time and improved separating capability, comprises a substantially flat-plate shaped bottom electrode (26) provided on lower side, a substantially flat-plate shaped mesh electrode (22) provided above the bottom electrode (26) as spaced a predetermined distance apart from the bottom electrode (26) and having a number of openings (24) to allow particles to pass therethrough, a direct current power supply connected to at least one of the mesh electrode (22) and the bottom electrode (24), and a voltage is applied across the bottom electrode (22) and the mesh electrode (24), thereby forming a separation zone (10) between the electrodes.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: October 10, 2006
    Assignee: Kawasaki Jukogyo Kabushiki Kaisha
    Inventors: Eiji Yoshiyama, Yasunori Shibata, Tetsuhiro Kinoshita
  • Patent number: 7073736
    Abstract: A shredder dust electrostatic separation apparatus separates and recovers various kinds of crushed pieces included in shredder dust by the use of electrostatic force. The apparatus includes a rotating drum made of a conductive material, which receives supplied shredder dust, a positive or negative voltage being applied thereon. The apparatus further includes a discharge wire strung along the sideline of the rotating drum. A negative or positive voltage is applied to the discharge wire to cause a discharge in a space between the discharge wire and the rotating drum. The various kinds of crushed pieces included in the shredder dust are charged by the discharge, the polarity of the crushed pieces being opposite to that of the rotating drum. The charged crushed pieces are attracted to the rotating drum. The charges of the crushed pieces are allowed to move to the rotating drum in accordance with the conductivities of the crushed pieces. Accordingly, there are differences in attraction force of the crushed pieces.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: July 11, 2006
    Inventor: Kenzo Takahashi
  • Patent number: 7045734
    Abstract: A D.C. voltage altering device includes at least one spark induction power conditioner including a first electrode connectable to a high voltage D.C. power source and a second electrode spaced from the first electrode and forming a discharging gap therebetween. The second electrode is connectable to a predetermined section of a physical separator and at least one of the electrodes is selectively positionable for altering spatial distance between same. The power conditioner induces a predetermined large amplitude, high frequency current ripple to the second electrode for creating a fluctuating voltage and fluctuating electrostatic field and maintaining continuous current flow through the gap without reversal of polarity. The spark induction power conditioner further includes a dielectric base for housing the electrodes and a plurality of fastening members threadably positionable through the base and engageable with the electrodes so that the discharging gap between the electrodes can be selectively adjusted.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: May 16, 2006
    Assignee: Outokumpu Oyj
    Inventors: Eric S. Yan, Thomas J. Grey
  • Patent number: 7012209
    Abstract: A method of collecting gold by flowing water over a gold collecting medium located in a sluice to induce a positive surface charge on the gold collecting medium. Feeding gold laden material into the sluice with the flowing water to induce a negative surface charge on gold particles of the gold laden material and create a slurry. Setting the flow rate of the slurry into the sluice such that the gold particles are attracted to the gold collecting medium. Finally, collecting the gold particles attracted to the gold collecting medium from the gold collecting medium. A gold separation device having a sluice having an input end and an output end; a water input directed into the input end of the sluice; and a gold collecting medium in the sluice. The gold collecting medium being of a material which incurs a positive surface charge when immersed in water.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: March 14, 2006
    Inventor: Wayne W. Loewen
  • Patent number: 6827761
    Abstract: Particles in a fluid flow are concentrated by a combination of electrical charging and focussing and passage through a virtual impact concentrator. The fluid is passed through an electrical charging section and an electrical focussing section and then to a virtual impact concentrator. The majority of charged particles in a selected size range are collected through a minor discharge passage extending axially from the virtual impact concentrator. The invention is particularly suitable for sampling engine exhaust gases and ambient aerosols.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: December 7, 2004
    Assignee: Her Majesty The Queen in Right of Canada as represented by the Minister of the Environment
    Inventor: Lisa A. Graham
  • Patent number: 6797908
    Abstract: The electrostatic classifier and separator is supported by a housing and includes a corona classifier section for classifying particulate materials according to size. Corona element supplies mobile ions for bombarding particulate materials dropping down a passageway from a reservoir. A splitter and screen may be included in the passageway to direct particulate materials into respective fractions. First separator section receives fine to middle size fractions and second separator section receives middle to coarse size fractions. A support frame having adjustable slots supports a plurality of static electrodes. Corona element for emitting a corona charge is spaced generally in a first quadrant of first separator section. A rotatable brush and an alternating current wiper may be included for removing fine to middle size nonconductive fractions from first separator section.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: September 28, 2004
    Assignee: Outokumpu Oyj
    Inventors: Eric S. Yan, Thomas J. Grey, Kevin R. McHenry
  • Patent number: 6789679
    Abstract: The invention concerns a method and apparatus for separating mineral particles according to their dielectric and/or electrophysical properties. In one practical example, rutile particles can be separated from zircon particles. In the method, the mineral particles which are to be separated are passed through a sharply non-homogenous electrical field. Particles with different dielectric and/or electrophysical properties are subjected to different forces which separate them spatially. The spatially separated particles are collected in discrete fractions.
    Type: Grant
    Filed: April 8, 2002
    Date of Patent: September 14, 2004
    Inventors: Vagiz Nurgalievich Abrarov, Sergei Dimitrievich Vaulin, Bojidara Grigorova, James Anthony Jude Tumilty, Christian Ghislain Schmidt
  • Publication number: 20030192813
    Abstract: The electrostatic classifier and separator is supported by a housing and includes a corona classifier section for classifying particulate materials according to size. Corona means supplies mobile ions for bombarding particulate materials dropping down a passageway from a reservoir. A splitter and screen may be included in the passageway to direct particulate materials into respective fractions. First separator section receives fine to middle size fractions and second separator section receives middle to coarse size fractions. A support frame having adjustable slots supports a plurality of static electrodes. Corona means for emitting a corona charge is spaced generally in a first quadrant of first separator section. A rotatable brush and an alternating current wiper may be included for removing fine to middle size nonconductive fractions from first separator section.
    Type: Application
    Filed: April 10, 2002
    Publication date: October 16, 2003
    Inventors: Eric S. Yan, Thomas J. Grey, Kevin R. McHenry
  • Publication number: 20030127368
    Abstract: The present invention relates to a method of classifying charged molecules such as proteins for quantitative analysis. An aliquot of a body serum is subjected to separation forces may be fluid drag and electrophoretic force in opposition.
    Type: Application
    Filed: December 17, 2001
    Publication date: July 10, 2003
    Applicant: Intel Corporation
    Inventor: Scott Sibbett
  • Patent number: 6498313
    Abstract: An electrostatic separation apparatus or system is provided for separating a particle mixture into two constituent species. The system includes a distributor for differentially tribocharging the particle species forming the mixture and supplying the charged mixture to a plurality of electrostatic separation cells. Each cell includes at least one separator having an inlet, a separation chamber having an electric field zone for drawing selected charged particles from the particle mixture, a collector, and a transition outlet. The length of the electric field zone is selectively adjustable for varying the charged particle drawing action. A curtain gas flow introduced into the separation chamber carries the selected charged particles drawn from the particle mixture in the electric field zone to the collector. Flow vanes or straighteners are provided for both the particle mixture flow and the curtain gas flow to reduce turbulence in the separation chamber and improve separation efficiency.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: December 24, 2002
    Assignee: University of Kentucky Research Foundation
    Inventors: John M. Stencel, John L. Schaefer, James K. Neathery, Heng Ban, Dennis Finseth
  • Patent number: 6452126
    Abstract: This invention relates to improving the separation efficiency in a triboelectric separator by adding media against which the components of the mixture will charge. As a result, random charging between the components of the mixture is reduced and controlled, and predictable charging is achieved.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: September 17, 2002
    Assignee: MBA Polymers, Inc.
    Inventors: Chuanfu Xiao, Laurence Allen, III
  • Patent number: 6390302
    Abstract: The invention concerns a method and apparatus for separating mineral particles according to their dielectric and/or electrophysical properties. In one practical example, rutile particles can be separated from zircon particles. In the method, the mineral particles which are to be separated are passed through a sharply non-homogenous electrical field. Particles with different dielectric and/or electrophysical properties are subjected to different forces which separate them spatially. The spatially separated particles are collected in discrete fractions.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: May 21, 2002
    Inventors: Vagiz Nurgalievich Abrarov, Sergei Dimitrievich Vaulin, Bojidara Grigorova, James Anthony Jude Tumilty, Christian Ghislain Schmidt
  • Patent number: 6365050
    Abstract: An improved flow field-flow fractionation (flow FFF) process has been developed which permits the high-resolution separation of analytes without stopping or reversing the axial flow, introducing additional axial flow streams, or further splitting the axial flow stream. The improved procedure speeds up, streamlines, and simplifies the apparatus and the procedure without unduly concentrating the sample, permits the use of flow-sensitive detection technologies in a manner which has previously been difficult or impossible, and avoids the artifactual aggregation which is known to result from other relaxation procedures. The process also permits the calculation of the channel width w without reference to system or void peaks in the fractogram. These capabilities render the improved flow FFF procedure more accurate as well as more practical, and permit automated flow FFF separations to be routinely performed on commercially-available HPLC systems with only minor modifications.
    Type: Grant
    Filed: August 22, 2000
    Date of Patent: April 2, 2002
    Assignee: Amgen Inc.
    Inventor: Gregory Paul Cauchon
  • Patent number: 6329623
    Abstract: This invention relates to an apparatus and method for electrostatically separating particles having different electrostatic properties. The apparatus involves two thin box-shaped electrodes facing each other as mirror-images and charged with a voltage field causing the opposing electrodes to assume opposite charges, and then passing a mixture of particles through the field so as to make the particles travel toward the respective electrodes through a perforated plate or screen and to a solid back plate and then to fall by gravity through a splitter adjusted to separate particles attracted by one charge from particles attracted by another charge. A vibrator is attached to each electrode, which is isolated for movement by spaced vibration isolators to shake off any particles stuck to the electrodes.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: December 11, 2001
    Assignee: Outokumpu Oyj
    Inventors: Eric S. Yan, Thomas J. Grey, Timo U. Niitti
  • Patent number: 6320148
    Abstract: A method of separating particulate materials of different properties has been developed. It consists of feeding a mixture of dry, powdered materials to one end of the surface of a planar electrode, which is vibrating to move the particles forward. At least one type of the particulate materials acquires a charge via conduction or triboelectrification. Those particles that acquire charges of the same sign as that of the planar electrode are lifted and collected at the V-shaped counter electrodes installed above. The new separation method is particularly useful for removing unburned carbons from fly ash and any other conducting materials from nonconducting ones.
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: November 20, 2001
    Inventors: Roe-Hoan Yoon, Oh-Hyung Han, Eric S. Yan, Byung-Wook Park
  • Patent number: 6168029
    Abstract: An improved method for separating electrically conductive components of an ore or mineral sand from electrically non-conductive components of the ore or mineral sand is disclosed which includes processing the ore, adding a polymer, such as an anionic polymer, to the processed ore, drying the polymer and ore, and then feeding the ore and polymer through an electrostatic separator. The addition of the anionic polymer to the processed ore increases the efficiency of the electrostatic separation process.
    Type: Grant
    Filed: May 12, 1999
    Date of Patent: January 2, 2001
    Assignee: Nalco Chemical Company
    Inventors: Raymond Leslie Henderson, Graeme Allan
  • Patent number: 5904253
    Abstract: In a belt separator system for separating constituents of a mixture of particles, the belt having a leading deflective surface at an acute angle to the direction of belt travel so as to impart a transverse momentum component to the constituent in a direction toward a longitudinal centerline of the belt separator system.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: May 18, 1999
    Assignee: Separation Technologies, Inc.
    Inventors: Thomas Cerullo, Charles E. Bozman, Thomas M. Dunn
  • Patent number: 5470554
    Abstract: A process is provided for recovering a saline mineral from an ore containing the saline mineral and impurities. The process generally comprises the steps of separating a first portion of impurities from the ore by density separation, electrostatically separating a second portion of impurities from the ore, and magnetically separating a third portion of impurities from the ore. The process can further include the steps of crushing the ore and dividing the crushed ore into a plurality of size fractions before the above-referenced separating steps. Furthermore, in order to increase the efficiency of the separating processes, the process of the present invention may further include the steps of drying the ore to remove surface moisture therefrom and de-dusting the ore to recover valuable fines.
    Type: Grant
    Filed: May 25, 1993
    Date of Patent: November 28, 1995
    Assignee: Environmental Projects, Inc.
    Inventors: Roland Schmidt, Dale L. Denham, Jr.
  • Patent number: 5375721
    Abstract: A dry placer mining machine and a belt assembly for use therewith. The machine concentrates metallic constituents from a gravel mix by fluidizing the mix with air which passes upwardly through the belt assembly, and moving the fluidized mix over the belt and applying an electrostatic charge thereto. The belt assembly is made up of a composite fabric belt member and a plurality of riffle members which extend transversely across this. The composite fabric belt member is constructed of non-conductive materials so as to minimize dissipation of the electrostatic charge, and this is made up of a finely woven cloth top layer, a reticulated foam middle layer, and a coarse mesh lower layer. The riffle members, in turn, are provided with insulation for preventing the electrostatic charge from being conducted away from the fabric belt member. The belt assembly is driven over the open upper end of a plenum chamber, and air pressure is supplied to this through a blower and ducting.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: December 27, 1994
    Inventor: Gordon LaVigne
  • Patent number: 5141651
    Abstract: A continuous flow FFF process for the separation of samples of particles which uses a modified channel structure to reduce the relaxation effect, reduce sample adhesion to the wall, and where possible eliminate the stop-flow procedure and thus greatly increase the speed and stability of operation, said modified channel comprises a thin channel whose thickness is reduced at the inlet end for a substantial distance beyond the inlet, such as the conventional triangular or near triangular piece, and then broadened out at the outlet end of the channel.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: August 25, 1992
    Assignee: University of Utah
    Inventor: John C. Giddings
  • Patent number: 5039426
    Abstract: A process for continuous particle and polymer separation comprising injecting a stream of carrier fluid containing the material to be separated into the inlet end of a thin channel, adjusting the flow rate to a sufficiently high level that flow-dependent lift forces the different components to different transverse positions by the time they reach the end of the channel, splitting the outlet flow into at least two substreams by means of physical splitters, adjusting the flowrates of the multiple substreams such that the transverse position of the outlet splitting plane divides the particles into enriched fractions, collecting the enriched or separated components from the emerging outlet streams.
    Type: Grant
    Filed: August 21, 1989
    Date of Patent: August 13, 1991
    Assignee: University of Utah
    Inventor: John C. Giddings
  • Patent number: 5006226
    Abstract: A fluidized, dry bed, ore concentrator in which a uniform air stream is utilized to fluidize ore particles within a region defined in part by two, moving, riffled surfaces. The particles are statically charged to enhance separation of particles within the fluidized mass. The less massive of the like-charged, fluidized particles are drawn off by a first riffled surface and denoted "tailings". The more massive, and valuable, of the particles are drawn off by the second of the two riffled surfaces and denoted as "fines".
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: April 9, 1991
    Inventor: Leo O. Burt, Jr.
  • Patent number: 4975182
    Abstract: The invention consists of forming an aqueous slurry of water and particles of ore carrying both metals and/or minerals which are passed at relatively high speed along an electrically isolated path in contact with electrically insulating materials and in the presence of air. This generates a positive electrostatic charge in the water droplets and enclosed particles and a negative charge in the electrically insulating materials through which they are being driven. The water droplets and hence the particles become differentially charged so that when they pass over an oppositely charged negative field, they are driven into the lower oppositely charged field body by the strong force of electrical attraction and the relatively weaker force of gravity. Should the negative collector contain an amalgamating material such as mercury and the ore, as an example contain gold, electrons are exchanged providing instant amalgamation of the surface of the gold.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: December 4, 1990
    Assignee: DCRS (Barbados) Ltd.
    Inventor: Robert R. Barefoot
  • Patent number: 4894146
    Abstract: A thin channel split flow process for particle fractionation which effects a rapid and efficient separation of the particles comprising continuously introducing two or more fluid substreams of different composition into separate inlet ports of a thin enclosed channel having a thickness which is very thin compared to the other two dimensions and bringing the substreams into contact with adjacent substreams so as to collectively form a series of thin laminae flowing parallel to one another in the channel and in contact with one another over a sufficient length of channel to allow a desired level of mass transport between and through laminae, continuously introducing a fluid medium containing the particles to be separated as one or more of the fluid substreams and independently of the particle concentration, varying the fluid composition of the different substreams as needed to realize separation, at the outlet end of the channel splitting the collective streams into another set of substreams so as to permit sep
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: January 16, 1990
    Assignee: University of Utah
    Inventor: John C. Giddings
  • Patent number: 4737268
    Abstract: A thin channel split flow process for particle fractionation which effects a rapid and efficient separation of the particles comprising introducing a stream of fluid containing the particles to be separated into the inlet end of a thin enclosed channel whose transverse dimension is very small, applying a special field or gradient or combination thereof transversely across the thin dimension of the channel to create a driving force a component of which is perpendicular to the main flow plane, adjusting the flow rate to achieve laminar flow conditions throughout the channel to allow the particles under the influence of the field/gradient to segregate into different stream laminae as they approach different transverse equilibrium positions, splitting the channel stream at the outlet end into substreams containing different separated fractions of the particles in the initial mixture, recovering the substream and thereby recovering the separated fractions.
    Type: Grant
    Filed: March 18, 1986
    Date of Patent: April 12, 1988
    Assignee: University of Utah
    Inventor: John C. Giddings
  • Patent number: 4615797
    Abstract: The electrostatic recovery of gold in the drywasher is improved by providing means to scavenge the waste heat from the internal combustion engine that powers the air blower. This preheats the intake air to the air blower, whereby the equilibrium temperature of the compressed air delivered to the partially fluidized bed of ore particles on the riffle table is raised about 50.degree. F. above ambient temperature. The layer of fabric underlying the bed of particles is maintained at bone dryness, the ore particles are dried, and the electrostatic forces operate under most favorable conditions at low relative humidity.
    Type: Grant
    Filed: June 18, 1985
    Date of Patent: October 7, 1986
    Inventor: Wayne G. Keene
  • Patent number: 4451357
    Abstract: An apparatus for dry placer mining to concentrate recoverable metallic constituents, such as gold or silver, from a dry gravel mix containing same is comprised of a frame for supporting and guiding an endless belt along a path including an upwardly inclined segment for receiving gravel particulate; an endless belt including a woven mesh belt member, a plurality of riffle members disposed in spaced parallel relationship within the intertices of the mesh member, and a composite fabric member disposed in face-to-face contact with the bottom surface of the mesh member; and a fluidizing member for passing a fluidizing gas upwardly through the endless belt along the inclined segment for fluidizing the gravel particulate and for establishing an electrostatic charge proximate the riffle members. The composite fabric member is specially constructed to permit a proper airflow for fluidizing the particulate and for assisting in the establishment of an electrostatic potential proximate the riffle members.
    Type: Grant
    Filed: May 17, 1982
    Date of Patent: May 29, 1984
    Inventor: Gordon LaVigne
  • Patent number: 4274947
    Abstract: A multi-constituent mixture of particles is fluidized within an elongated container with a gas permeable base. Opposing horizontal motions are induced in the upper and lower strata of the fluidized material by means of moving baffles mounted on endless chains within the confines of the container. A potential difference established between a horizontal electrode located in the upper part of the container above most of the bed surface, and the base of the bed induces electrostatic forces on the tribo-electrified particles, thereby affecting the distribution of the vertical composition of the mixture in the bed.The combination of the opposing horizontal motions and vertical segregation results in a horizontal concentration gradient. The particles thus separated are removed from the ends of the bed by, for example, flowing over weirs.
    Type: Grant
    Filed: January 14, 1980
    Date of Patent: June 23, 1981
    Inventors: Jan M. Beeckmans, Ion I. Inculet