EP0431965A2 - Séparation magnétique de matériau utilisant des courants de Foucault - Google Patents

Séparation magnétique de matériau utilisant des courants de Foucault Download PDF

Info

Publication number: EP0431965A2
Authority: EP; European Patent Office
Prior art keywords: particles; magnetic field; microwave; eddy currents; irradiated
Prior art date: 1989-12-07
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.): Granted

Application number

EP90313317A

Other languages

German (de)

English (en)

Other versions

EP0431965B1 (fr

EP0431965A3 (en

Inventor

Edwin Harm Roos

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.)

De Beers Industrial Diamond Division Pty Ltd

Original Assignee

De Beers Industrial Diamond Division Pty Ltd

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.)

1989-12-07

Filing date

1990-12-07

Publication date

1991-06-12

1990-12-07 Application filed by De Beers Industrial Diamond Division Pty Ltd filed Critical De Beers Industrial Diamond Division Pty Ltd

1991-06-12 Publication of EP0431965A2 publication Critical patent/EP0431965A2/fr

1991-08-21 Publication of EP0431965A3 publication Critical patent/EP0431965A3/en

1994-06-15 Application granted granted Critical

1994-06-15 Publication of EP0431965B1 publication Critical patent/EP0431965B1/fr

2010-12-07 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

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Classifications

- 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
- B03C1/02—Magnetic separation acting directly on the substance being separated
- B03C1/23—Magnetic separation acting directly on the substance being separated with material carried by oscillating fields; with material carried by travelling fields, e.g. generated by stationary magnetic coils; Eddy-current separators, e.g. sliding ramp
- 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

Definitions

THIS invention relates to a method and means for separating materials.
Mining operations almost invariably involve the extraction of valuable minerals which exist in very small quantities in the mined rock. This is particularly so in the case of valuable metals such as gold and silver.
the invention provides a method of separating particulate material according to the electrical conductivity of the particles of the material, the method comprising irradiating the particles with microwave or radio frequency electromagnetic radiation and subjecting the irradiated particles to a magnetic field so that eddy currents induced in the particles by the electromagnetic radiation interact with the magnetic field to cause movements, dependent upon electrical conductivity, of electrically conductive particles.
the particles are preferably irradiated with microwave radiation having a frequency in the range 109 Hz to 3 ⁇ 1011 Hz, or by radio wave radiation having a frequency in the range 104 Hz to 109 Hz.
the magnetic field may be a moving or stationary field.
the magnetic field may have a constant or varying intensity.
the particles are passed through a microwave chamber in which they are irradiated with microwave radiation and in which they are subjected to the magnetic field.
the particles are held in suspension in a liquid and are subjected to microwave irradiation and the magnetic field while so suspended.
the method of the invention can be used to separate gold particles from other particles.
the invention also provides an apparatus for separating particulate material according to the electrical conductivities of the particles of the material, the apparatus comprising means for irradiating the particles with microwave or radio frequency electromagnetic radiation and means for subjecting the irradiated particles to a magnetic field so that eddy currents induced in the particles by the electromagnetic radiation interact with the magnetic field to cause movements of electrically conductive particles dependent on their conductivities.
FIG. 1 shows an apparatus 10 which illustrates the principles of the method of the invention.
the Figure illustrates a microwave chamber 12 in which is mounted a microwave generator 14 for generating microwaves having a frequency in the range 109 Hz to 3 ⁇ 1011 Hz.
a glass dish 16 is placed on a conductive shielding plate 18 in the chamber 12 and contains an aqueous colloidal suspension 19 of fine gold particles together with other non-magnetic, non-conductive particles.
a permanent magnet 20 is placed beneath the conductive plate 18 and means (not shown) are provided for moving the magnet in the direction of the arrow 22 in Figure 1.
the magnetic field lines associated with the magnet 20 are vertical in Figure 1.
the magnet With the microwave generator in operation, the magnet is caused to move in the direction of the arrow 22.
the microwaves induce eddy currents in the gold particles in suspension.
Such eddy currents interact with the moving magnetic field and give rise to an electromotive force which in this case urges the gold particles to move to the right in Figure 1, i.e. in the same direction as the magnet moves.
the microwave frequency will be chosen to induce eddy currents of the desired magnitude in the desired particles so that the movement of those particles can be predicted and the desired particles recovered apart from other particles. In other words, the desired particles will be specifically targeted.
a non-specific microwave frequency may be used to cause differing degrees of movement of the various particle types.
An apparatus such as that of Figure 1 can be of practical benefit in assay procedures where it is desired, for instance, to determine the gold content of an ore sample.
the gold fraction is recovered and a computation may be made of the gold content of the sample as a whole.
milled and crushed ore particles 32 are fed onto an endless conveyor belt 34.
the ore particles 32 contain a low concentration of small particles of valuable electrically conductive material, such as gold, which are to be separated from other non-conductive material or less conductive materials in the mass of ore particles.
the particles pass through a microwave chamber 40 in which they are subjected to microwave radiation having a frequency in the range 109 Hz to 3 ⁇ 1011 Hz. While being irradiated the particles pass between magnets 36 (only one visible in Figure 2) located above and below the belt 34.
the magnets may be shielded from the microwaves by plates similar to the plate 18 of Figure 1.
the field lines associated with the magnets are perpendicular to the belt, i.e. into the plane of the paper in Figure 2.
the magnets 36 are arranged at 45° to the direction of belt movement, indicated by the arrows 38.
the magnetic field itself is at 45° to the direction of movement of the belt and particles.
the incident microwave radiation induces eddy currents in conductive particles. These eddy currents interact with the applied magnetic field to produce forces which tend to move the conductive particles sideways off the belt.
the exact frequency of the microwaves is chosen to produce eddy currents of sufficient magnitude in small conductive particles for the resultant electromotive force to be great enough to cause the relevant particles to fall sideways off the belt.
the remaining particles which are either non-conductive or less conductive than the particles which it is desired to separate are not moved off the belt and continue moving on the belt. Such particles are discharged over the discharge end of the belt for collection separately from those particles moved sideways off the belt.
the magnets 36 seen in Figure 2 may be arrangede to move in a direction at right angles to the direction of movement of the belt up and down as viewed in Figure 2. Also, there can be a number of magnets 36 arranged side-by-side to produce a "sweeping" magnetic field acting on the particles. A sweeping electromotive force, resulting from the interaction of the eddy currents with the magnetic fields of the various magnets moves the relevant particles progressively in a sideways direction off the belt.
Radio frequency electromagnetic radiation in the frequency range 104 Hz to 109 Hz can also be used.

Landscapes

Physical Or Chemical Processes And Apparatus (AREA)
Soft Magnetic Materials (AREA)
Superconductors And Manufacturing Methods Therefor (AREA)
Glass Compositions (AREA)
Mechanical Treatment Of Semiconductor (AREA)
Manufacture And Refinement Of Metals (AREA)
Load-Engaging Elements For Cranes (AREA)
Non-Insulated Conductors (AREA)
Compositions Of Macromolecular Compounds (AREA)

EP90313317A 1989-12-07 1990-12-07 Séparation magnétique de matériau utilisant des courants de Foucault Expired - Lifetime EP0431965B1 (fr)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
ZA899361		1989-12-07
ZA899361		1989-12-07

Publications (3)

Publication Number	Publication Date
EP0431965A2 true EP0431965A2 (fr)	1991-06-12
EP0431965A3 EP0431965A3 (en)	1991-08-21
EP0431965B1 EP0431965B1 (fr)	1994-06-15

Family

ID=25579930

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
EP90313317A Expired - Lifetime EP0431965B1 (fr)	1989-12-07	1990-12-07	Séparation magnétique de matériau utilisant des courants de Foucault

Country Status (7)

Country	Link
EP (1)	EP0431965B1 (fr)
JP (1)	JPH05345146A (fr)
AT (1)	ATE107194T1 (fr)
AU (1)	AU629073B2 (fr)
BR (1)	BR9006242A (fr)
CA (1)	CA2031663A1 (fr)
DE (1)	DE69009948T2 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
NZ243065A (en)	1991-06-13	1995-07-26	Lundbeck & Co As H	Piperidine derivatives and pharmaceutical compositions
CN114425548B (zh) *	2021-04-16	2024-12-27	顺尔茨环保(北京)有限公司	一种传统报废汽车资源化处理系统及方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US3463310A (en) *	1968-02-27	1969-08-26	Us Interior	Separation method
DE2336035A1 (de) *	1973-07-14	1975-02-06	Rosenthal Technik Ag	Vorbereitungsverfahren zur magnetischen aufbereitung von mineralgemischen
US4137156A (en) *	1975-03-21	1979-01-30	Occidental Petroleum Corporation	Separation of non-magnetic conductive metals
US4842721A (en) *	1982-10-19	1989-06-27	Raytheon Company	Transversely inclined ramp separator

1990
- 1990-12-06 CA CA002031663A patent/CA2031663A1/fr not_active Abandoned
- 1990-12-06 AU AU67807/90A patent/AU629073B2/en not_active Ceased
- 1990-12-07 EP EP90313317A patent/EP0431965B1/fr not_active Expired - Lifetime
- 1990-12-07 AT AT90313317T patent/ATE107194T1/de active
- 1990-12-07 DE DE69009948T patent/DE69009948T2/de not_active Expired - Fee Related
- 1990-12-07 BR BR909006242A patent/BR9006242A/pt not_active IP Right Cessation
- 1990-12-07 JP JP2414181A patent/JPH05345146A/ja active Pending

Also Published As

Publication number	Publication date
EP0431965B1 (fr)	1994-06-15
DE69009948T2 (de)	1994-11-03
DE69009948D1 (de)	1994-07-21
CA2031663A1 (fr)	1991-06-08
JPH05345146A (ja)	1993-12-27
AU629073B2 (en)	1992-09-24
ATE107194T1 (de)	1994-07-15
EP0431965A3 (en)	1991-08-21
AU6780790A (en)	1991-06-13
BR9006242A (pt)	1991-09-24

Legal Events

Date	Code	Title	Description
1991-04-26	PUAI	Public reference made under article 153(3) epc to a published international application that has entered the european phase	Free format text: ORIGINAL CODE: 0009012
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1991-10-23	RHK1	Main classification (correction)	Ipc: B03C 1/00
1992-02-12	17P	Request for examination filed	Effective date: 19911212
1993-01-07	17Q	First examination report despatched	Effective date: 19921124
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1997-06-30	BERE	Be: lapsed	Owner name: DE BEERS INDUSTRIAL DIAMOND DIVISION (PROPRIETARY Effective date: 19961231
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Publication	Publication Date	Title
US4137156A (en)	1979-01-30	Separation of non-magnetic conductive metals
US5161695A (en)	1992-11-10	Method and apparatus for separating particulate material according to conductivity
DK0898496T3 (da)	2002-08-19	Anordning og fremgangsmåde til partikelseparation med et roterende magnetsystem
US4003830A (en)	1977-01-18	Non-ferromagnetic materials separator
CA1074261A (fr)	1980-03-25	Classification de densite au moyen d'une boue ferro-paramagnetique
Knoll et al.	1985	Advances in electrostatic separation
US4416771A (en)	1983-11-22	Mine ore concentrator
Sivamohan et al.	1991	Electronic sorting and other preconcentration methods
EP0431965B1 (fr)	1994-06-15	Séparation magnétique de matériau utilisant des courants de Foucault
AU2014234959A1 (en)	2015-10-29	Processing mined material
Khalafalla	1985	Beneficiation with magnetic fluids—magnetic separation of the second kind
Can et al.	2007	Effect of microwave treatment on the flotation and magnetic separation properties of pyrite, chalcopyrite, galena and sphalerite
Spencer et al.	1975	Recovery of non-ferrous metals by means of permanent magnets
US4543178A (en)	1985-09-24	Dual intensity magnetic separation process for beneficiation of platinum ore
RU2159156C1 (ru)	2000-11-20	Устройство для сепарации и разделения тонкодисперсных минеральных смесей
SU934600A1 (ru)	1985-12-07	Способ электродинамической сепарации
SU1346253A1 (ru)	1987-10-23	Устройство дл извлечени электропроводных немагнитных частиц из потока сыпучего материала
FR2447228A1 (fr)	1980-08-22	Procede et dispositif de separation electrodynamique des materiaux pulverulents non magnetiques
SU732014A1 (ru)	1980-05-05	Устройство дл магнитогидродинамической сепарации
JPS6214977A (ja)	1987-01-23	スクラツプ分別装置
SU1044334A1 (ru)	1983-09-30	Способ магнитной сепарации
SU904783A1 (ru)	1982-02-15	Электромагнитный сепаратор
SU1003905A1 (ru)	1983-03-15	Устройство дл разделени электропроводных материалов
RU2264865C1 (ru)	2005-11-27	Способ обогащения цеолитсодержащих пород
Mita	2018	The effect of microwave radiation on the physicochemical properties of pyrite