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WO2007109858A1 - méthode et appareil pour chauffer les oxydes réfractaires - Google Patents

méthode et appareil pour chauffer les oxydes réfractaires Download PDF

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Publication number
WO2007109858A1
WO2007109858A1 PCT/AU2007/000401 AU2007000401W WO2007109858A1 WO 2007109858 A1 WO2007109858 A1 WO 2007109858A1 AU 2007000401 W AU2007000401 W AU 2007000401W WO 2007109858 A1 WO2007109858 A1 WO 2007109858A1
Authority
WO
WIPO (PCT)
Prior art keywords
refractory oxide
oxide material
melt
crucible
heating
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.)
Ceased
Application number
PCT/AU2007/000401
Other languages
English (en)
Inventor
Mark Tarnawski
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.)
LIQUID CERAMICS TECHNOLOGY Pty Ltd
Original Assignee
LIQUID CERAMICS TECHNOLOGY 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.)
Filing date
Publication date
Priority claimed from AU2006901551A external-priority patent/AU2006901551A0/en
Application filed by LIQUID CERAMICS TECHNOLOGY Pty Ltd filed Critical LIQUID CERAMICS TECHNOLOGY Pty Ltd
Publication of WO2007109858A1 publication Critical patent/WO2007109858A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
    • C03B5/021—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by induction heating
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/16—Special features of the melting process; Auxiliary means specially adapted for glass-melting furnaces
    • C03B5/24—Automatically regulating the melting process
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/653—Processes involving a melting step

Definitions

  • the present invention relates to a method and apparatus for heating refractory oxides and for materials containing refractory oxides.
  • Refractory oxides are insulators at low temperatures but become conductors when their temperature is raised above a certain temperature.
  • WO 2004/047495 discloses a method and apparatus for heating refractory oxides. Whilst the method and apparatus described therein can be effectively used to heat refractory oxides, it is not suited for large scale commercial processing applications where the quality of the refractory oxide varies considerably, or where the material to be heated comprises hazardous and other waste material, which while it contains refractory oxides is a material of unknown specific composition.
  • the present invention seeks to ameliorate the heating of refractory oxides by at least substantially overcoming the disadvantages associated with the abovementioned processes.
  • the present invention consists in a method of processing a refractory oxide material, said method comprising applying a high frequency electric field to heat said initial batch of refractory oxide material and applying a magnetic field to heat said initial batch of refractory oxide material, said high frequency electric field substantially heating said refractory oxide material to a temperature range at which said refractory oxide material undergoes a transition in electrical resistivity from an insulator to a conductor, and the magnetic field inductively heats said refractory oxide material during and/or after said transition, wherein during said heating an electrical plasma is initiated and maintained, and when said material is heated to a predetermined temperature to form a melt, characterised in that during heating the emission spectra of the plasma is measured thereby acquiring in-situ information of the chemical and physical properties of said melt.
  • said in-situ information can be used to monitor and control the continuous heating of said melt.
  • said in-situ information is processed, stored, analysed and reported.
  • said in-situ information is used to identify batches of the material being drawn off from said melt.
  • said melt is drawn off as a batch.
  • said high frequency electric field and said magnetic field is imparted to said refractory oxide material via a resonant structure.
  • the frequency imparted via the resonant structure is carried out within a first range of frequencies at which heating is substantially carried out by the electric field, and then subsequently lowered to a second range of frequencies at which heating is substantially carried out by the magnetic field.
  • Preferably said first range of frequencies is in the range of 13MHz-42MHz.
  • Preferably said second range of frequencies is in the range of 0.5MHz-13MHz.
  • said refractory oxide material is held within a container and said high frequency electric field is substantially imparted to said refractory oxide material by two spaced apart plates connected to an electric circuit, and said magnetic field is imparted by an RF coil surrounding said container.
  • said refractory oxide material is held with a non-faraday container and both said high frequency electric field and said magnetic field is imparted by an RP coil surrounding said non-faraday container.
  • Preferably said method is used in the manufacture of a synthetic gemstone.
  • Preferably said method is used to vitrify a hazardous or other waste material.
  • the present invention consists in a method of processing a material of unknown specific composition that includes a refractory oxide material, said method comprising applying a high frequency electric field to heat said initial batch of material of unknown specific composition and applying a magnetic field to heat said initial batch of material of unknown specific composition, said high frequency electric field substantially heating said material of unknown specific composition to a temperature range at which refractory oxide material contained within said material of unknown specific composition undergoes a transition in electrical resistivity from an insulator to a conductor, and the magnetic field inductively heats said refractory oxide material during and/or after said transition, wherein during said heating an electrical plasma is initiated and maintained, and when said material of unknown specific composition is heated to a temperature sufficient to form a melt, characterised in that during heating the emission spectra of the plasma is measured thereby acquiring in-situ information of the chemical and physical properties of said melt.
  • said in-situ information of the melt can be used to monitor and control the continuous heating of said melt.
  • said in-situ information is processed, stored, analysed and reported.
  • said in-situ information is used to identify at least one batch of the material being drawn off from said melt.
  • said melt is drawn off as a batch.
  • the present invention consists in a crucible apparatus for heating a refractory oxide material, said apparatus comprising a means for supporting said refractory oxide material, a means for imparting a high frequency electric field to said refractory oxide material and a means for imparting a magnetic field to said refractory oxide material in such a manner that when said material is heated an electrical plasma is initiated, characterised in that said apparatus further comprises acquisition means for acquiring in-situ information from the emission spectra of said plasma.
  • said acquisition means is connected to at least one control means for controlling the temperature of said refractory oxide material being heated within said apparatus.
  • said acquisition means is operably connected to at least one computer.
  • said computer comprises a controlling means for controlling the temperature of refractory oxide material being heated within said apparatus.
  • said computer is adapted to process, store, analyse and report, said in-situ information.
  • said in-situ information is used to identify at least one batch of the heated material being drawn off from said melt.
  • said apparatus comprises drawing off means for drawing off material heated therein.
  • said drawing off means is adapted to allow material to be drawn off in batches.
  • said drawing off means is adapted to allow material to be drawn off continuously, and said apparatus further comprises means for adding refractory oxide material thereto in response to material being drawn off.
  • said crucible comprises a resonant structure.
  • said apparatus comprising a container adapted to hold said refractory oxide material, and said means for imparting a magnetic field to said refractory oxide material is an RF coil surrounding said container.
  • said crucible is connected to a variable frequency generator.
  • variable frequency generator is adapted to impart a frequency in the range 0.5MHz-42MHz.
  • said means for imparting a high frequency electric field includes two spaced apart plates connected to an electric circuit.
  • the capacitance between said two spaced apart plates may be variably adjusted.
  • At least one of said two spaced apart plates is water-cooled.
  • said apparatus further comprises a sensing means for sensing the temperature of said refractory oxide material, said sensing means operably connected to a control means which varies the frequency imparted by said variable frequency generator relative to the sensed temperature.
  • said means for imparting a magnetic field to said refractory oxide material is adapted to substantially heat same at a frequency in the range 0.5MHz-13 MHz.
  • said means for imparting a electric field to said refractory oxide material is adapted to substantially heat same at a frequency in the range 13MHz-42 MHz.
  • said crucible apparatus comprises a non-faraday container adapted to hold said refractory oxide material, and said means for imparting an electric field to said refractory oxide material is an RF coil surrounding said non-faraday container, and said means for imparting a magnetic field to said refractory oxide material is said RF coil.
  • said acquisition means comprises a sensor connected to a spectrum analysis device.
  • said spectrum analysis device is any one of a spectrum analyser, spectrophotometer or atomic absorption analyser.
  • the present invention consists in a crucible apparatus for heating a material of unknown specific composition that includes a refractory oxide material, said apparatus comprising a means for supporting said refractory oxide material, a means for imparting a high frequency electric field to said refractory oxide material and a means for imparting a magnetic field to said refractory oxide material in such a manner that when said material is heated an electrical plasma is initiated, characterised in that said apparatus further comprises acquisition means for acquiring in-situ information from the emission spectra of said plasma.
  • said acquisition means is connected to at least one computer.
  • said computer comprises controlling means for controlling the temperature of material being heated within said apparatus.
  • said computer is adapted to process, store, analyse and report, said in-situ information.
  • said material of unknown specific composition is hazardous or other waste material.
  • said material of unknown specific composition is hazardous or other waste material, and said computer is adapted to at least partially identify the composition thereof.
  • said acquisition means comprises a sensor connected to a spectrum analysis device.
  • said spectrum analysis device is any one of a spectrum analyser, spectrophotometer or atomic absorption analyser.
  • Fig. 1 is a schematic depiction of a crucible apparatus according to a first embodiment of the present invention.
  • the abovementioned document describes a crucible 1 for heating and melting refractory oxides.
  • the crucible 1 is adapted to impart heating to the refractory oxide placed within container 3, firstly by imparting a high frequency electric field, typically in the range of 13 MHz -42MHz. Once the refractory oxide material reaches a temperature range where it undergoes a transition in electrical resistivity from an insulator to a conductor, the heating during and subsequent to the transition may be imparted by a magnetic field at a lower frequency, typically 0.5MHz- 13MHz. During heating an electrical plasma may be initiated and maintained within container 3.
  • an embodiment of the present invention comprises a crucible 1, of the type above described in WO2004/047495.
  • the crucible 1 further comprises a data acquisition device 30, in the form of a sensor 31 that is connected to a spectrum analyser 32, which is connected to a computer 40.
  • the sensor 31 gathers the emission spectra of the plasma 50 during heating.
  • This spectral information gathered from the plasma 50 which will further be referred to as "in-situ information” relates to the chemical and physical properties of the melt with which the plasma 50 is associated. This in-situ information may then be processed, stored and analysed.
  • This in-situ information may be used in "real time” to control the melting process as the computer 50 may include a control system (not shown) connected to variable frequency generator 8 and other components of crucible 1.
  • This in-situ information may be used for:
  • the crucible 1 is provided with a delivery means 61 for adding material to container 3, and a draw-off means 62 for drawing off melted material from the melt created within container 3.
  • the delivery means 61 and draw-off means 62 may be configured such that material being heated within crucible 1 can be processed in batches, and/or configured such that the material can be heated in a continuous process where material is added to the container 3, as material is drawn off.
  • a particular advantage of the present embodiment is that it can also be used to process a material of unknown specific composition that includes at least one refractory oxide material. This is particularly useful when the process is used for heating hazardous and other waste material.
  • the "in-situ information' gathered from plasma 50 via data acquisition device 30 can be used to identify the composition in the melt. This would then allow for batches of such hazardous and/or waste material, to be identified for future processing, material handling, and storage.
  • the apparatus and method of the present embodiment may be used to identify waste material containing asbestos fibre/cement or radioactive material, thereby ensuring that batches of such material are handled in a safe manner and if necessary neutralised and/or vitrified. Also waste materials that are not hazardous can be identified, such that batches of such non-hazardous waste can be formed into blocks for disposal or recycling.
  • the spectrum analyser 32 of the abovementioned embodiment may be any one of spectrophotometer, atomic absorption analyser or a similar device.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Structural Engineering (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)

Abstract

La présente invention concerne une méthode de traitement d'un matériau en oxyde réfractaire. La méthode comprend l'application d'un champ électrique à haute fréquence pour chauffer la charge initiale de matériau en oxyde réfractaire puis l'application d'un champ magnétique pour chauffer la charge initiale de matériau en oxyde réfractaire. Le champ électrique à haute fréquence chauffe sensiblement le matériau en oxyde réfractaire jusqu'à une plage de température à laquelle le matériau en oxyde réfractaire subit un changement de sa résistivité électrique, passant de l'état d'isolant à celui de conducteur. Le champ magnétique chauffe par induction le matériau en oxyde réfractaire pendant et/ou après le changement, et pendant la phase de chauffage il se crée et se maintient un plasma électrique. Lorsque le matériau est chauffé à une température prédéterminée afin de former un matériau fondu, au cours de la phase de chauffage, on mesure le spectre d'émission du plasma, obtenant ainsi des informations in situ sur les propriétés chimiques et physiques du matériau fondu.
PCT/AU2007/000401 2006-03-27 2007-03-26 méthode et appareil pour chauffer les oxydes réfractaires Ceased WO2007109858A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2006901551 2006-03-27
AU2006901551A AU2006901551A0 (en) 2006-03-27 Method and Apparatus for Heating Refractory Oxides

Publications (1)

Publication Number Publication Date
WO2007109858A1 true WO2007109858A1 (fr) 2007-10-04

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Application Number Title Priority Date Filing Date
PCT/AU2007/000401 Ceased WO2007109858A1 (fr) 2006-03-27 2007-03-26 méthode et appareil pour chauffer les oxydes réfractaires

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2544514A1 (es) * 2014-02-28 2015-08-31 Equilab, S.A. Equipo y procedimiento para preparación de muestras de análisis por rayos-X o ICP

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1572873A (en) * 1923-12-29 1926-02-16 Westinghouse Electric & Mfg Co High-frequency dielectric and magnetic furnace
US4401625A (en) * 1980-07-24 1983-08-30 Institut De Recherches De La Siderurgie Francaise Apparatus for preparing test samples
US4844612A (en) * 1986-10-03 1989-07-04 Commissariat A L'energie Atomique Apparatus for the analysis of elements by inductive plasma spectrometry produced by air
US6122050A (en) * 1998-02-26 2000-09-19 Cornell Research Foundation, Inc. Optical interface for a radially viewed inductively coupled argon plasma-Optical emission spectrometer
WO2004047495A1 (fr) * 2002-11-15 2004-06-03 Liquid Ceramics Technology Pty Ltd Procede et dispositif servant a rechauffer des oxydes refractaires

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1572873A (en) * 1923-12-29 1926-02-16 Westinghouse Electric & Mfg Co High-frequency dielectric and magnetic furnace
US4401625A (en) * 1980-07-24 1983-08-30 Institut De Recherches De La Siderurgie Francaise Apparatus for preparing test samples
US4844612A (en) * 1986-10-03 1989-07-04 Commissariat A L'energie Atomique Apparatus for the analysis of elements by inductive plasma spectrometry produced by air
US6122050A (en) * 1998-02-26 2000-09-19 Cornell Research Foundation, Inc. Optical interface for a radially viewed inductively coupled argon plasma-Optical emission spectrometer
WO2004047495A1 (fr) * 2002-11-15 2004-06-03 Liquid Ceramics Technology Pty Ltd Procede et dispositif servant a rechauffer des oxydes refractaires

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2544514A1 (es) * 2014-02-28 2015-08-31 Equilab, S.A. Equipo y procedimiento para preparación de muestras de análisis por rayos-X o ICP
WO2015128522A1 (fr) * 2014-02-28 2015-09-03 Equilab, S.A. Équipement et procédé de préparation d'échantillons d'analyse par rayons x ou icp

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