US3463310A - Separation method - Google Patents

Separation method Download PDF

Info

Publication number
US3463310A
US3463310A US708627A US3463310DA US3463310A US 3463310 A US3463310 A US 3463310A US 708627 A US708627 A US 708627A US 3463310D A US3463310D A US 3463310DA US 3463310 A US3463310 A US 3463310A
Authority
US
United States
Prior art keywords
coal
pyrite
heating
mixture
tunnel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US708627A
Other languages
English (en)
Inventor
Sabri Ergun
Martin Berman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Department of the Interior
Original Assignee
US Department of the Interior
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Department of the Interior filed Critical US Department of the Interior
Application granted granted Critical
Publication of US3463310A publication Critical patent/US3463310A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
    • C10B57/08—Non-mechanical pretreatment of the charge, e.g. desulfurization
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C1/00—Magnetic separation
    • B03C1/005—Pretreatment specially adapted for magnetic separation
    • B03C1/015—Pretreatment specially adapted for magnetic separation by chemical treatment imparting magnetic properties to the material to be separated, e.g. roasting, reduction, oxidation

Definitions

  • Some of the minerals which are known to display increased magnetic activity after heat treatment include pyrite, hematite, marcasite, siderite, chalcopyrite, arsenopyrite, bornite, pyrolusite and many others. Temperatures used in the heat treatment generally range from about 300 to 1000 C. for a contact time of few seconds to an hour or more. Treatment conditions used include oxidizing, inert and reducing atmospheres depending upon the mineral. Heat treatment followed by magnetic separation now finds its greatest use in ore concentration.
  • Finely divided coal can be subjected t a thermal treatment, usually in the presence of steam and air, to effect at least a partial conversion of the contained pyrite particles to pyrrhotite, magnetite and gamma-hematite. Because these minerals are all ferromagnetic while the original pyrite is paramagnetic, the treatment allows an elficient magnetic separation of the altered pyrite from the coal.
  • the pyrite-pyrrhotite transition takes place very rapidly at temperatures on the order of 600 C. and the pyrite to magnetite or hematite oxidation reaction also requires relatively high temperatures. Coal treatment temperatures as high as 360 C. have been used and alteration of the surfaces of pyrite grains to magnetic forms has been reported at these conditions.
  • the process of this invention takes advantage of the conductivity differences to electromagnetic radiation between pyrite and coal in order to selectively heat the surface of pyrite particles contained within the coal.
  • C011- version of at least the surface of pyrite particles to ferromagnetic forms is accomplished without substantial heating of the coal.
  • Another object of this invention is to alter at least the surface of a diamagnetic or paramagnetic mineral to ferromagnetic forms by selectively heating that mineral while it is in physical admixture with other components.
  • a specific object of this invention is to remove pyrite from coal.
  • the figure is a schematic flow diagram of a preferred embodiment of the separation process.
  • Tunnel irratiator 15 is of rectangular cross-section with electrically conducting walls. End sections 16 and 17 terminate the tunnel section and function to suppress the escape of electromagnetic energy. Coal is carried through tunnel 15 by continuous belt conveyor 12 formed of a dielectric material such as a reinforced Teflon. Conveyor 12 may be mounted on rotating drums 18 and 19 disposed one at each end of the tunnel as is conventional in the art. A driving force is applied to at least one of the drums in the direction indicated by arrow 20.
  • Electromagnetic energy produced by a suitable conventional source 21, is introduced into tunnel 15 by means of energy conduit 22.
  • conduit 22 comprises a waveguide of rectangular cross section having a series of openings spaced along the wall facing the interior of tunnel 15. Microwave energy is thus directed downwardly into the interior of the tunnel where it interacts with the pyrite and coal.
  • coaxial cables, striplines and the like may be utilized as the energy conduit rather than the waveguide.
  • Treatment time of the coal within the irradiating cavity or tunnel 15 is dependent upon the moisture content of the coal, the frequency of the electromagnetic radiation and the effective voltage gradient within the tunnel. Treatment times in the range of 1 to about 100 seconds are satisfactory for most coals over the frequency range investigated. At 10 ghz, exposure times of about 2 to 10 seconds were found satisfactory.
  • Optimum process efliicenies are obtained when only surface modilication of the individual pyrite particels to ferromagnetic forms has been achieved. Continued exposure results in more complete reaction of the pyrite but also results in undue heating of the coal. It is preferred that exposure time be limited to a pyrite conversion level of less than 10% and most preferably to a pyrite conversion level of less than 5%.
  • the treating gas may be introduced via conduit 23 at one end of tunnel 15 and removed via conduit 24.
  • the treating gas preferably is air.
  • Use of air as the treating gas performs two functions; it sweeps out water vapor released from the coal and it provides a EXAMPLE
  • Samples of finely divided coal containing pyrite were subjected to electromagnetic radiation at frequencies ranging from 400 khz to ghz. Throughout this frequency range, preferential heating of the contained pyrite was observed. As the frequency increased, the preferential heating of pyrite relative to coal become more pronounced. Pyrite in the mixture thus treated was strongly attracted to a magnet and no losses of coal volatiles were observed.
  • the electromagnetic treatment may be performed using any other applicable type of high frequency heating equipment.
  • a coaxial tube arrangement having an annular treatment chamber with the electromagnetic radiation facilities arranged within the inner tube may also be used to advantage
  • the process has been illustrated as being particularly applicable to the removal of pyrite from coal.
  • separations may be performed on other mineral mixtures.
  • any mineral mixture having at least one member which is susceptible to being altered to a more highly magnetic form upon heating can be treated by this process.
  • a pyrite-chalcopyrite-silicate ore which may be treated to produce a copper concentrate.
  • a process for the separation of a mixture of particulate materials, at least one of said materials being susceptible to a change in its magnetic properties upon heating which comprises subjecting said mixture to electromagnetic radiation having a frequency whereat said material susceptible to a change in magnetic properties absorbs electromagnetic energy ⁇ more strongly than does the other components in said mixture and is thereby preferentially heated, continuing the irradiation for a time sufficient t0 cause conversion of at least a surface layer of said particulate material being susceptible to such a change to a more highly magnetic form, terminating the irradiation before substantial heating of the other components of the mixture occurs, subjecting said irradiated mixture to a magnetic separation step and recovering a portion enriched in said magnetically altered material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Solid Fuels And Fuel-Associated Substances (AREA)
US708627A 1968-02-27 1968-02-27 Separation method Expired - Lifetime US3463310A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US70862768A 1968-02-27 1968-02-27

Publications (1)

Publication Number Publication Date
US3463310A true US3463310A (en) 1969-08-26

Family

ID=24846562

Family Applications (1)

Application Number Title Priority Date Filing Date
US708627A Expired - Lifetime US3463310A (en) 1968-02-27 1968-02-27 Separation method

Country Status (2)

Country Link
US (1) US3463310A (de)
DE (1) DE1758135B2 (de)

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3969225A (en) * 1974-04-04 1976-07-13 I. Jordan Kunik Differential separation of particulates by combined electro-static and radio frequency means
US3976557A (en) * 1974-11-29 1976-08-24 Hydrocarbon Research, Inc. Pretreatment of coal-derived liquid to improve magnetic separation of solids
US4052170A (en) * 1976-07-09 1977-10-04 Mobil Oil Corporation Magnetic desulfurization of airborne pulverized coal
US4077871A (en) * 1975-04-14 1978-03-07 Occidental Petroleum Corporation Separation of colored particulate glass
US4193767A (en) * 1977-06-08 1980-03-18 Fipke Charles E Particulate mineral separation process
WO1980002220A1 (en) * 1979-04-09 1980-10-16 D Brandon An apparatus and method for thawing materials stored in gondola-type containers
US4252638A (en) * 1977-12-07 1981-02-24 Klockner-Humboldt-Deutz Ag Method for the desulfurization of coal
US4259560A (en) * 1977-09-21 1981-03-31 Rhodes George W Process for drying coal and other conductive materials using microwaves
US4342640A (en) * 1980-11-24 1982-08-03 Chevron Research Company Magnetic separation of mineral particles from shale oil
US4359379A (en) * 1979-12-21 1982-11-16 Nippon Oil Company, Ltd. Process for fluid catalytic cracking of distillation residual oils
US4388179A (en) * 1980-11-24 1983-06-14 Chevron Research Company Magnetic separation of mineral particles from shale oil
US4406773A (en) * 1981-05-13 1983-09-27 Ashland Oil, Inc. Magnetic separation of high activity catalyst from low activity catalyst
US4466362A (en) * 1982-03-03 1984-08-21 Massachusetts Institute Of Technology Method of removing sulfur and other contaminants from the coal in coal-oil slurries
US4661118A (en) * 1985-04-15 1987-04-28 The United States Of America, As Represented By The Secretary Of The Interior Method for oxidation of pyrite in coal to magnetite and low field magnetic separation thereof
EP0431965A2 (de) * 1989-12-07 1991-06-12 De Beers Industrial Diamond Division (Proprietary) Limited Magnettrennung von Material mit Wirbelströmen
US5096066A (en) * 1987-11-30 1992-03-17 Genesis Research Corporation Process for beneficiating particulate solids
US5153838A (en) * 1987-11-30 1992-10-06 Genesis Research Corporation Process for beneficiating particulate solids
US5161695A (en) * 1989-12-07 1992-11-10 Roos Edwin H Method and apparatus for separating particulate material according to conductivity
US5171424A (en) * 1990-10-22 1992-12-15 Ashland Oil, Inc. Magnetic separation of old from new cracking catalyst by means of heavy rare earth "magnetic hooks"
US5190635A (en) * 1989-04-03 1993-03-02 Ashland Oil, Inc. Superparamagnetic formation of FCC catalyst provides means of separation of old equilibrium fluid cracking catalyst
US5262962A (en) * 1987-11-30 1993-11-16 Genesis Research Corporation Process for beneficiating particulate solids
US5538624A (en) * 1994-10-21 1996-07-23 Ashland Inc. Process, apparatus and compositions for recycle of cracking catalyst additives
WO2003072835A1 (en) * 2002-02-22 2003-09-04 Wave Separation Technologies Llc Method and apparatus for separating metal values
US7318528B1 (en) * 2004-07-26 2008-01-15 Iradj Hessabi Precious metal recovery
US7571814B2 (en) 2002-02-22 2009-08-11 Wave Separation Technologies Llc Method for separating metal values by exposing to microwave/millimeter wave energy
US20100038288A1 (en) * 2008-08-12 2010-02-18 MR&E, Ltd. Refining coal-derived liquid from coal gasification, coking, and other coal processing operations
US20110011720A1 (en) * 2009-07-14 2011-01-20 Rinker Franklin G Process for treating agglomerating coal by removing volatile components
US20110011722A1 (en) * 2009-07-14 2011-01-20 Rinker Franklin G Process for treating coal by removing volatile components
CN103447148A (zh) * 2013-08-08 2013-12-18 内蒙古科技大学 利用微波还原含赤铁矿物料的磁选装置及磁选方法
US8968520B2 (en) 2011-06-03 2015-03-03 National Institute Of Clean And Low-Carbon Energy (Nice) Coal processing to upgrade low rank coal having low oil content
US9005322B2 (en) 2011-07-12 2015-04-14 National Institute Of Clean And Low-Carbon Energy (Nice) Upgrading coal and other carbonaceous fuels using a lean fuel gas stream from a pyrolysis step
US9074138B2 (en) 2011-09-13 2015-07-07 C2O Technologies, Llc Process for treating coal using multiple dual zone steps
US9163192B2 (en) 2010-09-16 2015-10-20 C2O Technologies, Llc Coal processing with added biomass and volatile control
US9327320B1 (en) 2015-01-29 2016-05-03 Green Search, LLC Apparatus and method for coal dedusting
JP2016164285A (ja) * 2015-03-06 2016-09-08 国立大学法人九州大学 選鉱方法
JP2016164286A (ja) * 2015-03-06 2016-09-08 国立大学法人九州大学 選鉱方法
US9598646B2 (en) 2013-01-09 2017-03-21 C20 Technologies, Llc Process for treating coal to improve recovery of condensable coal derived liquids
CN111298953A (zh) * 2020-03-13 2020-06-19 中国矿业大学 一种发电厂燃前粉煤高梯度磁选脱硫方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1478295A (en) * 1920-10-06 1923-12-18 Metals Production Company Of N Treatment of complex sulphide ores
US1512870A (en) * 1920-09-02 1924-10-21 Krupp Ag Grusonwerk Method of recovering fuel from residues
US2907456A (en) * 1957-05-21 1959-10-06 Int Salt Co Separation of materials
US3097160A (en) * 1959-11-30 1963-07-09 Rosen Alfred H Method of separating differentially heated particles

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1512870A (en) * 1920-09-02 1924-10-21 Krupp Ag Grusonwerk Method of recovering fuel from residues
US1478295A (en) * 1920-10-06 1923-12-18 Metals Production Company Of N Treatment of complex sulphide ores
US2907456A (en) * 1957-05-21 1959-10-06 Int Salt Co Separation of materials
US3097160A (en) * 1959-11-30 1963-07-09 Rosen Alfred H Method of separating differentially heated particles

Cited By (55)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3969225A (en) * 1974-04-04 1976-07-13 I. Jordan Kunik Differential separation of particulates by combined electro-static and radio frequency means
US3976557A (en) * 1974-11-29 1976-08-24 Hydrocarbon Research, Inc. Pretreatment of coal-derived liquid to improve magnetic separation of solids
US4077871A (en) * 1975-04-14 1978-03-07 Occidental Petroleum Corporation Separation of colored particulate glass
US4052170A (en) * 1976-07-09 1977-10-04 Mobil Oil Corporation Magnetic desulfurization of airborne pulverized coal
US4193767A (en) * 1977-06-08 1980-03-18 Fipke Charles E Particulate mineral separation process
US4259560A (en) * 1977-09-21 1981-03-31 Rhodes George W Process for drying coal and other conductive materials using microwaves
US4252638A (en) * 1977-12-07 1981-02-24 Klockner-Humboldt-Deutz Ag Method for the desulfurization of coal
WO1980002220A1 (en) * 1979-04-09 1980-10-16 D Brandon An apparatus and method for thawing materials stored in gondola-type containers
US4359379A (en) * 1979-12-21 1982-11-16 Nippon Oil Company, Ltd. Process for fluid catalytic cracking of distillation residual oils
US4342640A (en) * 1980-11-24 1982-08-03 Chevron Research Company Magnetic separation of mineral particles from shale oil
US4388179A (en) * 1980-11-24 1983-06-14 Chevron Research Company Magnetic separation of mineral particles from shale oil
US4406773A (en) * 1981-05-13 1983-09-27 Ashland Oil, Inc. Magnetic separation of high activity catalyst from low activity catalyst
US4466362A (en) * 1982-03-03 1984-08-21 Massachusetts Institute Of Technology Method of removing sulfur and other contaminants from the coal in coal-oil slurries
US4661118A (en) * 1985-04-15 1987-04-28 The United States Of America, As Represented By The Secretary Of The Interior Method for oxidation of pyrite in coal to magnetite and low field magnetic separation thereof
US5096066A (en) * 1987-11-30 1992-03-17 Genesis Research Corporation Process for beneficiating particulate solids
US5153838A (en) * 1987-11-30 1992-10-06 Genesis Research Corporation Process for beneficiating particulate solids
US5262962A (en) * 1987-11-30 1993-11-16 Genesis Research Corporation Process for beneficiating particulate solids
US5280836A (en) * 1987-11-30 1994-01-25 Genesis Research Corporation Process for beneficiating particulate solids
US5190635A (en) * 1989-04-03 1993-03-02 Ashland Oil, Inc. Superparamagnetic formation of FCC catalyst provides means of separation of old equilibrium fluid cracking catalyst
EP0431965A2 (de) * 1989-12-07 1991-06-12 De Beers Industrial Diamond Division (Proprietary) Limited Magnettrennung von Material mit Wirbelströmen
EP0431965A3 (en) * 1989-12-07 1991-08-21 De Beers Industrial Diamond Division (Proprietary) Limited Magnetic separation of material using eddy currents
AU629073B2 (en) * 1989-12-07 1992-09-24 De Beers Industrial Diamond Division (Proprietary) Limited Material separation
US5161695A (en) * 1989-12-07 1992-11-10 Roos Edwin H Method and apparatus for separating particulate material according to conductivity
US5171424A (en) * 1990-10-22 1992-12-15 Ashland Oil, Inc. Magnetic separation of old from new cracking catalyst by means of heavy rare earth "magnetic hooks"
US5538624A (en) * 1994-10-21 1996-07-23 Ashland Inc. Process, apparatus and compositions for recycle of cracking catalyst additives
AU2003216298A1 (en) * 2002-02-22 2003-09-09 Wave Separation Technologies Llc Method and apparatus for separating metal values
US20040258591A1 (en) * 2002-02-22 2004-12-23 Birken Stephen M. Method and apparatus for separating metal values
US6923328B2 (en) 2002-02-22 2005-08-02 Wave Separation Technologies Llc Method and apparatus for separating metal values
US7571814B2 (en) 2002-02-22 2009-08-11 Wave Separation Technologies Llc Method for separating metal values by exposing to microwave/millimeter wave energy
CN100532592C (zh) * 2002-02-22 2009-08-26 波分离技术有限责任公司 分离有价值的金属用的方法和设备
US20090267275A1 (en) * 2002-02-22 2009-10-29 Wave Separation Technologies Llc Method and Apparatus for Separating Metal Values
US8469196B2 (en) 2002-02-22 2013-06-25 Wave Separation Technologies, Llc Method and apparatus for separating metal values
WO2003072835A1 (en) * 2002-02-22 2003-09-04 Wave Separation Technologies Llc Method and apparatus for separating metal values
US7318528B1 (en) * 2004-07-26 2008-01-15 Iradj Hessabi Precious metal recovery
US20110168541A1 (en) * 2008-08-12 2011-07-14 Warwick James S Refining Coal-Derived Liquid From Coal Gasification, Coking and Other Coal Processing Operations
US20100038288A1 (en) * 2008-08-12 2010-02-18 MR&E, Ltd. Refining coal-derived liquid from coal gasification, coking, and other coal processing operations
US8197678B2 (en) 2008-08-12 2012-06-12 MR & E, Ltd. Refining coal-derived liquid from coal gasification, coking and other coal processing operations
US8394240B2 (en) 2009-07-14 2013-03-12 C2O Technologies, Llc Process for treating bituminous coal by removing volatile components
US8366882B2 (en) 2009-07-14 2013-02-05 C20 Technologies, Llc Process for treating agglomerating coal by removing volatile components
US20110011722A1 (en) * 2009-07-14 2011-01-20 Rinker Franklin G Process for treating coal by removing volatile components
US8470134B2 (en) 2009-07-14 2013-06-25 C2O Technologies, Llc Process for treating coal by removing volatile components
US20110011720A1 (en) * 2009-07-14 2011-01-20 Rinker Franklin G Process for treating agglomerating coal by removing volatile components
US20110011719A1 (en) * 2009-07-14 2011-01-20 Rinker Franklin G Process for treating bituminous coal by removing volatile components
US9163192B2 (en) 2010-09-16 2015-10-20 C2O Technologies, Llc Coal processing with added biomass and volatile control
US8968520B2 (en) 2011-06-03 2015-03-03 National Institute Of Clean And Low-Carbon Energy (Nice) Coal processing to upgrade low rank coal having low oil content
US9523039B2 (en) 2011-07-12 2016-12-20 Shenhua Group Corporation Limited Upgrading coal and other carbonaceous fuels using a lean fuel gas stream from a pyrolysis step
US9005322B2 (en) 2011-07-12 2015-04-14 National Institute Of Clean And Low-Carbon Energy (Nice) Upgrading coal and other carbonaceous fuels using a lean fuel gas stream from a pyrolysis step
US9074138B2 (en) 2011-09-13 2015-07-07 C2O Technologies, Llc Process for treating coal using multiple dual zone steps
US9598646B2 (en) 2013-01-09 2017-03-21 C20 Technologies, Llc Process for treating coal to improve recovery of condensable coal derived liquids
CN103447148B (zh) * 2013-08-08 2016-02-17 内蒙古科技大学 利用微波还原含赤铁矿物料的磁选装置及磁选方法
CN103447148A (zh) * 2013-08-08 2013-12-18 内蒙古科技大学 利用微波还原含赤铁矿物料的磁选装置及磁选方法
US9327320B1 (en) 2015-01-29 2016-05-03 Green Search, LLC Apparatus and method for coal dedusting
JP2016164285A (ja) * 2015-03-06 2016-09-08 国立大学法人九州大学 選鉱方法
JP2016164286A (ja) * 2015-03-06 2016-09-08 国立大学法人九州大学 選鉱方法
CN111298953A (zh) * 2020-03-13 2020-06-19 中国矿业大学 一种发电厂燃前粉煤高梯度磁选脱硫方法

Also Published As

Publication number Publication date
DE1758135A1 (de) 1971-03-04
DE1758135B2 (de) 1972-04-06

Similar Documents

Publication Publication Date Title
US3463310A (en) Separation method
Uslu et al. Microwave heating of coal for enhanced magnetic removal of pyrite
US20080069746A1 (en) Method and apparatus for microwave induced pyrolysis of arsenical ores and ore concentrates
US4416771A (en) Mine ore concentrator
US4252638A (en) Method for the desulfurization of coal
US2132404A (en) Method of separating magnetic material
Korobeinikov et al. Radiation-thermal treatment in ore dressing
US5161695A (en) Method and apparatus for separating particulate material according to conductivity
US3097160A (en) Method of separating differentially heated particles
Can et al. Effect of microwave treatment on the flotation and magnetic separation properties of pyrite, chalcopyrite, galena and sphalerite
GB925637A (en) Process for the comminution of siliceous iron ores
US3318447A (en) Separation of high and low quality electrode cokes
US2717205A (en) Process of treating low grade ores
Jacobs et al. Tracking pyritic sulfur in the microwave desulfurization of coal
Chanturiya et al. Use of high-power electromagnetic pulses in processes of disintegration and opening of rebellious gold-containing raw material
DE10260744A1 (de) Verfahren und Anlage zum thermischen Behandeln von körnigen Feststoffen
US4205979A (en) Process for beneficiating oxide ores
US2754965A (en) Beneficiation of nonmetallic minerals
US3233030A (en) Apparatus for high frequency treatment of ore
GB905555A (en) A process for the shattering of ores and rocks by high frequency electro-magnetic fields
US2847123A (en) Drying method
US1556449A (en) Procerss for treating tin ores, concentrates, tailings, or the like
Jordan A continuous dielectric separator for mineral beneficiation
SU934600A1 (ru) Способ электродинамической сепарации
US3016139A (en) Method of beneficiating mica