WO1994000533A1 - Treatment of waste - Google Patents

Treatment of waste Download PDF

Info

Publication number
WO1994000533A1
WO1994000533A1 PCT/AU1993/000317 AU9300317W WO9400533A1 WO 1994000533 A1 WO1994000533 A1 WO 1994000533A1 AU 9300317 W AU9300317 W AU 9300317W WO 9400533 A1 WO9400533 A1 WO 9400533A1
Authority
WO
WIPO (PCT)
Prior art keywords
bath
reaction zone
waste
method defined
gas
Prior art date
Application number
PCT/AU1993/000317
Other languages
French (fr)
Inventor
David Steward Conochie
Robin John Batterham
Terry Alan Matthews
Original Assignee
Technological Resources Pty. Limited
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 Technological Resources Pty. Limited filed Critical Technological Resources Pty. Limited
Priority to KR1019940704813A priority Critical patent/KR100267206B1/en
Priority to BR9306633A priority patent/BR9306633A/en
Priority to EP93912467A priority patent/EP0648255B1/en
Priority to AU43005/93A priority patent/AU670594B2/en
Priority to US08/360,732 priority patent/US5640708A/en
Priority to CA 2139220 priority patent/CA2139220C/en
Priority to RU94046210A priority patent/RU2105785C1/en
Priority to JP50189194A priority patent/JP3534407B2/en
Priority to DE69324682T priority patent/DE69324682T2/en
Publication of WO1994000533A1 publication Critical patent/WO1994000533A1/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/57Gasification using molten salts or metals
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D3/00Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
    • A62D3/30Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
    • A62D3/32Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents by treatment in molten chemical reagent, e.g. salts or metals
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B09DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09BDISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
    • B09B3/00Destroying solid waste or transforming solid waste into something useful or harmless
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10BDESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B49/00Destructive distillation of solid carbonaceous materials by direct heating with heat-carrying agents including the partial combustion of the solid material to be treated
    • C10B49/14Destructive distillation of solid carbonaceous materials by direct heating with heat-carrying agents including the partial combustion of the solid material to be treated with hot liquids, e.g. molten metals
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10BDESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B53/00Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/04Pesticides, e.g. insecticides, herbicides, fungicides or nematocides
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/08Toxic combustion residues, e.g. toxic substances contained in fly ash from waste incineration
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/40Inorganic substances
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0913Carbonaceous raw material
    • C10J2300/0946Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0956Air or oxygen enriched air
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/10Process efficiency
    • Y02P20/129Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S423/00Chemistry of inorganic compounds
    • Y10S423/09Reaction techniques
    • Y10S423/12Molten media

Definitions

  • the present invention relates to the treatment of inorganic solid waste.
  • the present invention relates to the treatment of inorganic solid waste which is commonly referred to as "dusts”.
  • dusts as used herein is understood to mean any relatively finely divided particulate material and includes but is not limited to:
  • inorganic residues arising from the combination or incineration of toxic, hazardous and non- hazardous wastes, including fly ash, bottom ash and particulate material collected by gas cleaning systems.
  • dusts In many instances, for a range of environmental and materials handling reasons it is difficult and expensive to dispose of dusts. For example, dusts often contain hazardous compounds and require particular processing before disposal. In addition, dusts often contain components which, whilst valuable, cannot be recovered economically. It is an object of the present invention to provide a method of treating dusts which alleviates the disadvantages described in the preceding paragraphs.
  • a method of treating inorganic solid waste in a bath of molten metal contained in a vessel which has a space above the bath and a waste gas outlet comprising:
  • references herein to "a bath of molten metal” cover a bath containing mo ten metal and slag as well as a bath containing molten ⁇ r ⁇ ta_ only.
  • the present invention is based partly en the realisation that a molten metal bath provides a suitable environment, both in terms of temperature and composition, for converting inorganic solid waste, particularly dusts, into more readily disposable components.
  • the present invention is also based partly on the realisation that the use of a secondary reaction zone for oxidising any oxidisable products released from the molten metal bath provides a means of minimising the energy input to maintain the temperature of the molten metal bath.
  • the method further comprises injecting a gas into the bath to cause splashes and/or droplets of molten metal to be ejected upwardly from the bath into the secondary reaction zone or into a section of the space above the bath which is between the secondary reaction zone and the waste gas outlet to facilitate efficient heat transfer to the bath and scrubbing of volatilised species and any particulate material in the products released from the primary reaction zone and/or produced in the secondary reaction zone.
  • the combination of the oxidation of any oxidisable products in the secondary reaction zone and the scrubbing effect provided by the splashes and/or droplets of molten metal in the secondary reaction zone or downstream thereof provides a high level of assurance against unreacted or partially reacted inorganic solid waste short-circuiting treatment altogether and reporting in the exit gas stream from the vessel. This is achieved by providing at least two separate reaction zones through which unreacted or partially reacted inorganic waste must pass before exiting the vessel.
  • the method further comprises injecting carbonaceous material into the bath to form a carburising zone in which the carbon in the carbonaceous material dissolves into the bath and is available for reaction with waste in the primary reaction zone.
  • carbonaceous material is herein understood to include: solid carbonaceous fuels such as coke and coal; liquid fuels such as oil, light fuel oil, diesel oil and heavy fuel oil; and gaseous fuels, such as natural gas, methane, ethane, propane, butane; or any mixtures of the fuels.
  • the carbonaceous material be selected from one or more of the group comprising coal, spent pot linings from aluminium smelting furnaces, and sewage sludge. It is particularly preferred that the carbonaceous material comprises coal.
  • the heat transferred to the bath from the secondary reaction zone contributes to balancing the heat loss from the bath as a consequence of endothermic reactions in the carburising and primary reaction zones.
  • One particularly preferred embodiment comprises locating the carburising zone directly below the secondary reaction zone.
  • the bath comprises at least 10% metal. It is particularly preferred that the bath comprises at least 70% metal. It is more particularly preferred that the bath comprises at least 80% metal.
  • the metal be selected from one or more from the group comprising iron, ferroalloys, nickel, tin, chromium, silicon, and copper, and mixtures thereof. It is particularly preferred that the metal comprises iron.
  • the gas injected into the bath to cause molten metal and slag splashes and/or droplets to be ejected upwardly into the secondary reaction zone be selected from one or more of an inert gas, recycled process gas, natural gas, C0 2 , propane, or butane, or mixtures of the gases. It is particularly preferred that the inert gas be nitrogen.
  • the oxygen-containing gas be selected from the group comprising oxygen, air and steam. It is particularly preferred that the air be preheated. It is more particularly preferred that the air be preheated to temperatures in the range of 900 to 1600°C.
  • the preferred embodiment of the method is carried out in a vessel generally identified by the numeral 3.
  • the vessel 3 may be of any suitable known design of metallurgical vessel with refractory lined internal walls and an outer metal shell.
  • the vessel 3 is a generally cylindrical shape disposed horizontally and has bottom tuyeres 5, 7, a slag/metal tap 9, an air injection port 10, and an upper off-gas outlet 11 at one end of the vessel 3.
  • the ratio of the length and the diameter of the vessel is 3:1.
  • the vessel 3 contains a volume of molten metal which comprises at least 10% iron and a layer of slag at a temperature of 1400°C.
  • the other metals in the bath may be selected as required and, by way of example, may comprise one or more of ferroalloys, tin, nickel, silicon and copper.
  • the preferred embodiment of the method comprises injecting dusts entrained in a suitable carrier, such as an inert gas, through the bottom tuyeres 5 into the bath to form a primary reaction zone indicated schematically by the line identified by the numeral 13 which is located at the end of the vessel 3 remote from the off-gas outlet 11.
  • a suitable carrier such as an inert gas
  • the dusts undergo a range of reactions and phase changes in the primary reaction zone 13 depending on the composition of the dusts.
  • the metal oxides in the dusts are reduced and the metal values report into the bath or in some cases are volatilised.
  • Other components of the dusts may be broken down or volatilised and released directly into the gas space above the bath.
  • the method also comprises injecting pre-heated air, typically at a temperature in the range of 900 to 1600°C, or any other suitable oxygen-containing gas through injection port 10 towards the surface of the bath adjacent the primary reaction zone 13 to form a secondary reaction zone indicated schematically by the line identified by the numeral 17 in the section of the space above the bath that is located between the section that is directly above the primary reaction zone 13 and the off-gas outlet 11.
  • pre-heated air typically at a temperature in the range of 900 to 1600°C, or any other suitable oxygen-containing gas
  • the method also comprises simultaneously injecting nitrogen or any other suitable gas through tuyeres 7 into the bath immediately below the secondary reaction zone 17 to cause eruption of molten metal and slag in splashes and/or droplets from the surface of the bath into the secondary reaction zone 17.
  • the nitrogen is injected in an amount greater than or equal to 0.1 Nm 3 rnin "1 tonne "1 of molten metal in the bath.
  • the pre-heated air oxidises any oxidisable products from the primary reaction zone 13. Furthermore, the heat released by such oxidation is efficiently transferred to the splashes and/or droplets of molten metal and slag and subsequently into the bath when the splashes and/or droplets fall downwardly to the surface of the bath.
  • the splashes and/or droplets also scrub volatilised species and any particulate material from the primary reaction zone 13 and/or formed in the secondary reaction zone 17 and transfer the scrubbed values to the bath.
  • the carbonaceous material be selected from one or more of the group comprising coal, spent pot linings from aluminium smelting furnaces, and sewage sludge. It is particularly preferred that the carbonaceous material comprises coal.
  • the temperature in the secondary reaction zone 17 is controlled to be at least 200°C higher than that of the molten metal.
  • the temperature in the secondary reaction zone 13 varies between 1500°C and 2700°C.
  • the secondary reaction zone 17 has three important functions. Specifically, the secondary reaction zone 17:
  • the preheated air may be injected into the secondary reaction zone 17 by any suitable means such as top-blowing single or multiple tuyeres or lances with one or more openings.
  • the method also comprises injecting carbonaceous material such as coal into the bath through tuyeres 7 to form a carburisation zone indicated schematically by the line identified by the numeral 15.
  • the volatiles in the coal are thermally cracked and the carbon dissolves in the iron and disperses through the bath and in particular into the primary reaction zone 13.
  • the heat transfer to the bath is important since reduction reactions in the primary reaction zone 13 and the carburisation zone 15 are essentially endothermic and it is important to balance the heat loss due to such reactions to maintain the temperature of the bath at an effective operating level.
  • the preferred embodiment of the method of the present invention is an efficient means by which solid inorganic waste, particularly dusts, can be converted into component parts which are non-hazardous and comparatively straight ⁇ forward to recover.
  • the preferred embodiment includes the location of the secondary reaction zone 17 immediately above the carburisation zone 15, it can readily be appreciated that the present invention is not so limited and the secondary rea ion zone 17 may be located above a section of the bath t- ⁇ &t is adjacent to the carburisation zone 15.
  • the preferred embodiment comprises injecting nitrogen or any other suitable gas into the bath to cause eruption of molten metal and slag splashes and droplets to form a curtain in the secondary reaction zr 17,
  • the curtain of splashes and droplets of molten metal may be projected into a section of the bath which is between the secondary reaction zone 17 and the waste outlet 11 so that products, gaseous or solid, fl-win f ⁇ om the secondary reaction zone 17 are required to pass through the curtain before reaching the waste gas outlet 11.
  • the curtain enables heat transfer back to the bath and scrubbing of volatilised species and any particulate material flowing from the secondary reaction zone 17.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Combustion & Propulsion (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Business, Economics & Management (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Toxicology (AREA)
  • General Health & Medical Sciences (AREA)
  • Emergency Management (AREA)
  • Processing Of Solid Wastes (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Removal Of Specific Substances (AREA)
  • Treatment Of Sludge (AREA)

Abstract

A method of treating inorganic solid waste in a bath of molten metal contained in a vessel (3) which has a space above the bath and a waste gas outlet (11) is disclosed. The method comprises injecting waste into the bath to form a primary reaction zone (13) in which there are reactions between the waste and the bath or in which the waste undergoes a change of phase to convert the waste into more readily recoverable or disposable products. The method further comprises injecting oxygen-containing gas towards the surface of the bath to form a secondary reaction zone (17) in a section of the space above the bath through which oxidisable products released from the primary reaction zone (13) flow to reach the waste gas outlet (11) in the vessel (3) and in which the oxidisable products are oxidised and the heat released by such oxidation is transferred into the bath.

Description

TREATMENT OF WASTE
The present invention relates to the treatment of inorganic solid waste.
In particular, the present invention relates to the treatment of inorganic solid waste which is commonly referred to as "dusts".
The term "dusts" as used herein is understood to mean any relatively finely divided particulate material and includes but is not limited to:
(a) metallic or metallic oxide containing material substantially collected by gas cleaning systems operated, for example, as a component of pyro- metallurgical production and processing; and/or
(b) inorganic residues arising from the combination or incineration of toxic, hazardous and non- hazardous wastes, including fly ash, bottom ash and particulate material collected by gas cleaning systems.
In many instances, for a range of environmental and materials handling reasons it is difficult and expensive to dispose of dusts. For example, dusts often contain hazardous compounds and require particular processing before disposal. In addition, dusts often contain components which, whilst valuable, cannot be recovered economically. It is an object of the present invention to provide a method of treating dusts which alleviates the disadvantages described in the preceding paragraphs.
According to the present invention there is provided a method of treating inorganic solid waste in a bath of molten metal contained in a vessel which has a space above the bath and a waste gas outlet, the method comprising:
(a) injecting waste into the bath to form a primary reaction zone in which there are reactions between the waste and the bath or in which the waste undergoes a change of phase to convert the waste into more readily recoverable or disposable products; and
(b) injecting oxygen-containing gas towards the surface of the bath to form a secondary reaction zone in a section of the space above the bath through which oxidiβable products released from the primary reaction zone flow to reach the waste gas outlet in the vessel and in which the oxidisable products are oxidised and the heat released by such oxidation is transferred into the bath.
It is understood that references herein to "a bath of molten metal" cover a bath containing mo ten metal and slag as well as a bath containing molten ιr~ta_ only.
The present invention is based partly en the realisation that a molten metal bath provides a suitable environment, both in terms of temperature and composition, for converting inorganic solid waste, particularly dusts, into more readily disposable components. The present invention is also based partly on the realisation that the use of a secondary reaction zone for oxidising any oxidisable products released from the molten metal bath provides a means of minimising the energy input to maintain the temperature of the molten metal bath.
It is preferred that the method further comprises injecting a gas into the bath to cause splashes and/or droplets of molten metal to be ejected upwardly from the bath into the secondary reaction zone or into a section of the space above the bath which is between the secondary reaction zone and the waste gas outlet to facilitate efficient heat transfer to the bath and scrubbing of volatilised species and any particulate material in the products released from the primary reaction zone and/or produced in the secondary reaction zone.
It can readily be appreciated that the combination of the oxidation of any oxidisable products in the secondary reaction zone and the scrubbing effect provided by the splashes and/or droplets of molten metal in the secondary reaction zone or downstream thereof provides a high level of assurance against unreacted or partially reacted inorganic solid waste short-circuiting treatment altogether and reporting in the exit gas stream from the vessel. This is achieved by providing at least two separate reaction zones through which unreacted or partially reacted inorganic waste must pass before exiting the vessel.
It is particularly preferred that the method further comprises injecting carbonaceous material into the bath to form a carburising zone in which the carbon in the carbonaceous material dissolves into the bath and is available for reaction with waste in the primary reaction zone.
The term carbonaceous material is herein understood to include: solid carbonaceous fuels such as coke and coal; liquid fuels such as oil, light fuel oil, diesel oil and heavy fuel oil; and gaseous fuels, such as natural gas, methane, ethane, propane, butane; or any mixtures of the fuels.
It is preferred that the carbonaceous material be selected from one or more of the group comprising coal, spent pot linings from aluminium smelting furnaces, and sewage sludge. It is particularly preferred that the carbonaceous material comprises coal.
In the above described embodiment the heat transferred to the bath from the secondary reaction zone contributes to balancing the heat loss from the bath as a consequence of endothermic reactions in the carburising and primary reaction zones.
One particularly preferred embodiment comprises locating the carburising zone directly below the secondary reaction zone.
It is preferred that the bath comprises at least 10% metal. It is particularly preferred that the bath comprises at least 70% metal. It is more particularly preferred that the bath comprises at least 80% metal.
It is preferred that the metal be selected from one or more from the group comprising iron, ferroalloys, nickel, tin, chromium, silicon, and copper, and mixtures thereof. It is particularly preferred that the metal comprises iron.
It is preferred that the gas injected into the bath to cause molten metal and slag splashes and/or droplets to be ejected upwardly into the secondary reaction zone be selected from one or more of an inert gas, recycled process gas, natural gas, C02, propane, or butane, or mixtures of the gases. It is particularly preferred that the inert gas be nitrogen.
It is preferred that the oxygen-containing gas be selected from the group comprising oxygen, air and steam. It is particularly preferred that the air be preheated. It is more particularly preferred that the air be preheated to temperatures in the range of 900 to 1600°C.
The present invention is described further with reference to the accompanying figure which is a schematic illustration of a preferred embodiment of a method of treating inorganic solid waste in accordance with the present invention.
The preferred embodiment of the method of the present invention is described hereinafter in the context of treating dusts although it is understood that the present invention is not so restricted and extends to the treatment of solid inorganic waste generally.
The preferred embodiment of the method is carried out in a vessel generally identified by the numeral 3.
The vessel 3 may be of any suitable known design of metallurgical vessel with refractory lined internal walls and an outer metal shell. In the arrangement shown in the figure the vessel 3 is a generally cylindrical shape disposed horizontally and has bottom tuyeres 5, 7, a slag/metal tap 9, an air injection port 10, and an upper off-gas outlet 11 at one end of the vessel 3. Typically, the ratio of the length and the diameter of the vessel is 3:1.
The vessel 3 contains a volume of molten metal which comprises at least 10% iron and a layer of slag at a temperature of 1400°C. The other metals in the bath may be selected as required and, by way of example, may comprise one or more of ferroalloys, tin, nickel, silicon and copper.
The preferred embodiment of the method comprises injecting dusts entrained in a suitable carrier, such as an inert gas, through the bottom tuyeres 5 into the bath to form a primary reaction zone indicated schematically by the line identified by the numeral 13 which is located at the end of the vessel 3 remote from the off-gas outlet 11. The dusts undergo a range of reactions and phase changes in the primary reaction zone 13 depending on the composition of the dusts. Typically, the metal oxides in the dusts are reduced and the metal values report into the bath or in some cases are volatilised. Other components of the dusts may be broken down or volatilised and released directly into the gas space above the bath.
The method also comprises injecting pre-heated air, typically at a temperature in the range of 900 to 1600°C, or any other suitable oxygen-containing gas through injection port 10 towards the surface of the bath adjacent the primary reaction zone 13 to form a secondary reaction zone indicated schematically by the line identified by the numeral 17 in the section of the space above the bath that is located between the section that is directly above the primary reaction zone 13 and the off-gas outlet 11.
The method also comprises simultaneously injecting nitrogen or any other suitable gas through tuyeres 7 into the bath immediately below the secondary reaction zone 17 to cause eruption of molten metal and slag in splashes and/or droplets from the surface of the bath into the secondary reaction zone 17. Typically, the nitrogen is injected in an amount greater than or equal to 0.1 Nm3 rnin"1 tonne"1 of molten metal in the bath.
In the secondary reaction zone 17 the pre-heated air oxidises any oxidisable products from the primary reaction zone 13. Furthermore, the heat released by such oxidation is efficiently transferred to the splashes and/or droplets of molten metal and slag and subsequently into the bath when the splashes and/or droplets fall downwardly to the surface of the bath. The splashes and/or droplets also scrub volatilised species and any particulate material from the primary reaction zone 13 and/or formed in the secondary reaction zone 17 and transfer the scrubbed values to the bath.
It is preferred that the carbonaceous material be selected from one or more of the group comprising coal, spent pot linings from aluminium smelting furnaces, and sewage sludge. It is particularly preferred that the carbonaceous material comprises coal.
It is noted that in effect the splashes and/or droplets of molten metal and slag form a curtain which is an effective and efficient means of transferring heat to the bath and scrubbing volatilised species and particulate material from products from the primary reaction zone 13 and/or secondary reaction zone 17.
Typically, the temperature in the secondary reaction zone 17 is controlled to be at least 200°C higher than that of the molten metal. Typically, the temperature in the secondary reaction zone 13 varies between 1500°C and 2700°C.
It can be readily appreciated from the foregoing that in the preferred embodiment of the method the secondary reaction zone 17 has three important functions. Specifically, the secondary reaction zone 17:
(a.) oxidises any oxidisable products from the primary reaction zone 13;
(b) ensures that the heat released by such oxidation is transferred to the bath; and
(c) scrubs any volatilised species and any particulate material from the primary reaction zone 13 and/or formed in the secondary reaction zone 17.
The preheated air may be injected into the secondary reaction zone 17 by any suitable means such as top-blowing single or multiple tuyeres or lances with one or more openings.
In many instances, the reduction of metal oxides in the dusts to metal values will be a dominant reaction in the primary reaction zone 13. As a consequence, in such situations, in order to maintain a level of carbon in the bath to reduce efficiently the metal oxides in the dusts, the method also comprises injecting carbonaceous material such as coal into the bath through tuyeres 7 to form a carburisation zone indicated schematically by the line identified by the numeral 15. The volatiles in the coal are thermally cracked and the carbon dissolves in the iron and disperses through the bath and in particular into the primary reaction zone 13.
It is noted that the heat transfer to the bath is important since reduction reactions in the primary reaction zone 13 and the carburisation zone 15 are essentially endothermic and it is important to balance the heat loss due to such reactions to maintain the temperature of the bath at an effective operating level.
It can be readily appreciated from the foregoing that the preferred embodiment of the method of the present invention is an efficient means by which solid inorganic waste, particularly dusts, can be converted into component parts which are non-hazardous and comparatively straight¬ forward to recover.
In addition, it can be readily appreciated that the use of two separate reaction zones in the preferred embodiment provides a high level of assurance against unreacted dusts, which may include hazardous components, short-circuiting treatment altogether.
Many modifications may be made to the preferred embodiment of the method of the present invention without departing from the spirit and scope of the present invention. In this regard, whilst in the preferred embodiment the inorganic solids and coal are injected into the bath to form separate, essentially macro-sized, reaction and carburisation zones in the bath, it can readily be appreciated that the present invention is not so limited and the injection of the constituents into the bath can be controlled to form arrays of separate essentially micro- sized primary reaction and carburisation zones.
Furthermore, whilst the preferred embodiment includes the location of the secondary reaction zone 17 immediately above the carburisation zone 15, it can readily be appreciated that the present invention is not so limited and the secondary rea ion zone 17 may be located above a section of the bath t-^&t is adjacent to the carburisation zone 15.
Furthermore, whilst the preferred embodiment comprises injecting nitrogen or any other suitable gas into the bath to cause eruption of molten metal and slag splashes and droplets to form a curtain in the secondary reaction zr 17, it can readily be appreciated that the present invention is not so limited. By way of example, the curtain of splashes and droplets of molten metal and may be projected into a section of the bath which is between the secondary reaction zone 17 and the waste outlet 11 so that products, gaseous or solid, fl-win f^om the secondary reaction zone 17 are required to pass through the curtain before reaching the waste gas outlet 11. As a consequence, the curtain enables heat transfer back to the bath and scrubbing of volatilised species and any particulate material flowing from the secondary reaction zone 17.

Claims

CLAIMS :
1. A method of treating inorganic solid waste in a bath of molten metal in a vessel which has a space above the bath and a waste gas outlet, the method comprising:
(a) injecting waste into the bath to form a primary reaction zone in which there are reactions between the waste and the bath or in which the waste undergoes a change of phase to convert the waste into more readily recoverable or disposable products; and
(b) injecting oxygen-containing gas towards the surface of the bath to form a secondary reaction zone in a section of the space above the bath through which oxidisable products released from the primary reaction zone flow to reach the waste gas outlet and in which the oxidisable products are oxidised and the heat released by such oxidation is transferred into the bath.
2. The method defined in claim 1, further comprising injecting a gas into the bath to cause splashes and/or droplets of molten metal to be ejected upwardly from the bath into the secondary reaction zone or into a section of the space above the bath which is between the secondary reaction zone and the waste gas outlet to facilitate efficient heat transfer to the bath and scrubbing of volatilised species and any particulate material in the products released from the primary reaction zone and/or formed in the secondary reaction zone.
3. The method defined in claim 1 or claim 2, further comprising injecting carbonaceous material into the bath to form a carburising zone in which the carbon in the carbonaceous material dissolves into the bath and is available for reaction with waste in the primary reaction zone.
4. The method defined in claim 3, wherein the carbonaceous material is selected from one or more of the group comprising coal, spent pot linings from aluminium smelting furnaces, and sewage sludge.
5. The method defined in claim 4, wherein the carbonaceous material comprises coal.
6. The method defined in any one of claims 3 to 6, further comprising locating the carburising zone directly below the secondary reaction zone.
7. The method defined in any one of the preceding claims, wherein the bath comprises at least 10% metal.
8. The method defined in claim 7, wherein the bath comprises at least 70% metal.
9. The method defined in claim 8, wherein the bath comprises at least 80% metal.
10. The method defined in any one of the preceding claims, wherein the metal is selected from one or more of the group comprising iron, ferroalloys, nickel, tin, chromium, silicon, and copper, and mixtures thereof.
11. The method defined in claim 2, wherein the gas injected into the bath to cause molten metal and slag splashes and/or droplets to be ejected upwardly into the secondary reaction zone is selected from one or more of an inert gas, recycled process gas, natural gas, C02, propane, or butane, or mixtures of the gases.
12. The method defined in claim 11, wherein the inert gas is nitrogen.
13. The method defined in any one of the preceding claims, wherein the oxygen-containing gas is selected from the group comprising oxygen, air and steam.
14. The method defined in claim 13, further comprising preheating the air.
15. The method defined in claim 14, wherein the air is preheated to temperatures in the range of 900 to 1600°C.
PCT/AU1993/000317 1992-06-29 1993-06-29 Treatment of waste WO1994000533A1 (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
KR1019940704813A KR100267206B1 (en) 1992-06-29 1993-06-29 Treatment of waste
BR9306633A BR9306633A (en) 1992-06-29 1993-06-29 Inorganic solid waste treatment process
EP93912467A EP0648255B1 (en) 1992-06-29 1993-06-29 Treatment of waste
AU43005/93A AU670594B2 (en) 1992-06-29 1993-06-29 Treatment of waste
US08/360,732 US5640708A (en) 1992-06-29 1993-06-29 Treatment of waste
CA 2139220 CA2139220C (en) 1992-06-29 1993-06-29 Treatment of waste
RU94046210A RU2105785C1 (en) 1992-06-29 1993-06-29 Method of processing inorganic solid wastes
JP50189194A JP3534407B2 (en) 1992-06-29 1993-06-29 Waste treatment method
DE69324682T DE69324682T2 (en) 1992-06-29 1993-06-29 WASTE TREATMENT

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPL3215 1992-06-29
AUPL321592 1992-06-29

Publications (1)

Publication Number Publication Date
WO1994000533A1 true WO1994000533A1 (en) 1994-01-06

Family

ID=3776256

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1993/000317 WO1994000533A1 (en) 1992-06-29 1993-06-29 Treatment of waste

Country Status (10)

Country Link
US (1) US5640708A (en)
EP (1) EP0648255B1 (en)
JP (1) JP3534407B2 (en)
KR (1) KR100267206B1 (en)
AT (1) ATE179453T1 (en)
BR (1) BR9306633A (en)
DE (1) DE69324682T2 (en)
RU (1) RU2105785C1 (en)
WO (1) WO1994000533A1 (en)
ZA (1) ZA934643B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996027412A1 (en) * 1995-03-07 1996-09-12 Molten Metal Technology, Inc. Feed processing employing dispersed molten droplets
WO1996040373A1 (en) * 1995-06-07 1996-12-19 Molten Metal Technology, Inc. Vaporizable material injection into molten bath

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AUPN226095A0 (en) 1995-04-07 1995-05-04 Technological Resources Pty Limited A method of producing metals and metal alloys
AUPO426396A0 (en) 1996-12-18 1997-01-23 Technological Resources Pty Limited A method of producing iron
AUPO426096A0 (en) 1996-12-18 1997-01-23 Technological Resources Pty Limited Method and apparatus for producing metals and metal alloys
AUPO944697A0 (en) * 1997-09-26 1997-10-16 Technological Resources Pty Limited A method of producing metals and metal alloys
AUPP442598A0 (en) 1998-07-01 1998-07-23 Technological Resources Pty Limited Direct smelting vessel
MY119760A (en) 1998-07-24 2005-07-29 Tech Resources Pty Ltd A direct smelting process
AUPP483898A0 (en) 1998-07-24 1998-08-13 Technological Resources Pty Limited A direct smelting process & apparatus
AUPP554098A0 (en) 1998-08-28 1998-09-17 Technological Resources Pty Limited A process and an apparatus for producing metals and metal alloys
AUPP570098A0 (en) 1998-09-04 1998-10-01 Technological Resources Pty Limited A direct smelting process
AUPP647198A0 (en) 1998-10-14 1998-11-05 Technological Resources Pty Limited A process and an apparatus for producing metals and metal alloys
AUPP805599A0 (en) 1999-01-08 1999-02-04 Technological Resources Pty Limited A direct smelting process
AUPQ083599A0 (en) 1999-06-08 1999-07-01 Technological Resources Pty Limited Direct smelting vessel
AUPQ152299A0 (en) 1999-07-09 1999-08-05 Technological Resources Pty Limited Start-up procedure for direct smelting process
AUPQ205799A0 (en) 1999-08-05 1999-08-26 Technological Resources Pty Limited A direct smelting process
AUPQ213099A0 (en) 1999-08-10 1999-09-02 Technological Resources Pty Limited Pressure control
AUPQ308799A0 (en) 1999-09-27 1999-10-21 Technological Resources Pty Limited A direct smelting process
AUPQ346399A0 (en) 1999-10-15 1999-11-11 Technological Resources Pty Limited Stable idle procedure
AUPQ365799A0 (en) 1999-10-26 1999-11-18 Technological Resources Pty Limited A direct smelting apparatus and process
US6602321B2 (en) 2000-09-26 2003-08-05 Technological Resources Pty. Ltd. Direct smelting process
KR100621713B1 (en) 2000-09-26 2006-09-13 테크놀라지칼 리소시스 피티와이. 리미티드. Upgrading solid material
US9216905B2 (en) * 2011-06-03 2015-12-22 Ronald G. Presswood, Jr. Gasification or liquefaction of coal using a metal reactant alloy composition
NZ594187A (en) * 2011-07-21 2013-10-25 Irvine Technology Ltd Waste Treatment Process
US10427192B2 (en) 2015-05-15 2019-10-01 Ronald G. Presswood, Jr. Method to recycle plastics, electronics, munitions or propellants using a metal reactant alloy composition
HRP20240498T1 (en) * 2017-08-30 2024-07-05 Circular Resources (Ip) Pte Limited Waste processing system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU3487668A (en) * 1968-10-08 1970-09-10 Monzino Riotinto Of Australia Limited Tin smelting
AU7299674A (en) * 1973-09-12 1976-03-11 Uss Eng & Consult Gasification of coal
DE3608005A1 (en) * 1986-03-11 1987-10-01 Dornier System Gmbh Process for disposing of special waste
DE3906869C1 (en) * 1989-03-03 1989-11-02 Klimanek Gmbh, 6680 Wiebelskirchen, De Process for producing a concentrate enrichment of metals or oxides thereof from filter dusts by expelling them from the filter dusts in their vapour form and thus collecting them in concentrated form

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
LU71435A1 (en) * 1974-12-06 1976-11-11
DE3031680A1 (en) * 1980-08-22 1982-03-11 Klöckner-Werke AG, 4100 Duisburg METHOD FOR GAS GENERATION
DE3607775A1 (en) * 1986-03-08 1987-09-17 Kloeckner Cra Tech METHOD FOR MELTING REDUCTION OF IRON ORE
US5191154A (en) * 1991-07-29 1993-03-02 Molten Metal Technology, Inc. Method and system for controlling chemical reaction in a molten bath
US5354940A (en) * 1991-07-29 1994-10-11 Molten Metal Technology, Inc. Method for controlling chemical reaction in a molten metal bath
DE69225470T2 (en) * 1991-12-06 1999-01-14 Tech Resources Pty Ltd Processing waste
US5324341A (en) * 1992-05-05 1994-06-28 Molten Metal Technology, Inc. Method for chemically reducing metals in waste compositions

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU3487668A (en) * 1968-10-08 1970-09-10 Monzino Riotinto Of Australia Limited Tin smelting
AU7299674A (en) * 1973-09-12 1976-03-11 Uss Eng & Consult Gasification of coal
DE3608005A1 (en) * 1986-03-11 1987-10-01 Dornier System Gmbh Process for disposing of special waste
DE3906869C1 (en) * 1989-03-03 1989-11-02 Klimanek Gmbh, 6680 Wiebelskirchen, De Process for producing a concentrate enrichment of metals or oxides thereof from filter dusts by expelling them from the filter dusts in their vapour form and thus collecting them in concentrated form

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5744117A (en) * 1993-04-12 1998-04-28 Molten Metal Technology, Inc. Feed processing employing dispersed molten droplets
WO1996027412A1 (en) * 1995-03-07 1996-09-12 Molten Metal Technology, Inc. Feed processing employing dispersed molten droplets
WO1996040373A1 (en) * 1995-06-07 1996-12-19 Molten Metal Technology, Inc. Vaporizable material injection into molten bath
US5679132A (en) * 1995-06-07 1997-10-21 Molten Metal Technology, Inc. Method and system for injection of a vaporizable material into a molten bath

Also Published As

Publication number Publication date
BR9306633A (en) 1998-12-08
ZA934643B (en) 1994-01-11
EP0648255A4 (en) 1995-07-12
RU94046210A (en) 1996-10-27
DE69324682D1 (en) 1999-06-02
DE69324682T2 (en) 1999-12-23
JP3534407B2 (en) 2004-06-07
RU2105785C1 (en) 1998-02-27
KR100267206B1 (en) 2000-11-01
EP0648255A1 (en) 1995-04-19
KR950702229A (en) 1995-06-19
US5640708A (en) 1997-06-17
EP0648255B1 (en) 1999-04-28
ATE179453T1 (en) 1999-05-15
JPH07508457A (en) 1995-09-21

Similar Documents

Publication Publication Date Title
US5640708A (en) Treatment of waste
US5776420A (en) Apparatus for treating a gas formed from a waste in a molten metal bath
US5358697A (en) Method and system for controlling chemical reaction in a molten bath
US5585532A (en) Method for treating a gas formed from a waste in a molten metal bath
US5354940A (en) Method for controlling chemical reaction in a molten metal bath
US5744117A (en) Feed processing employing dispersed molten droplets
EP0200743B1 (en) Destruction of toxic chemicals
US5298233A (en) Method and system for oxidizing hydrogen- and carbon-containing feed in a molten bath of immiscible metals
US5396850A (en) Treatment of waste
US5395405A (en) Method for producing hydrocarbon gas from waste
US5640709A (en) Method and apparatus for producing a product in a regenerator furnace from impure waste containing a non-gasifiable impurity
US6074623A (en) Process for thermal destruction of spent potliners
CA2139220C (en) Treatment of waste
AU4300593A (en) Treatment of waste
EP0644789A1 (en) Method for treating organic waste.
Thornblom et al. Utilizing plasma technology for chemical reactions in controlled atmosphere
WO1996025202A1 (en) Refractory barrier layer and method of formation

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AT AU BB BG BR BY CA CH CZ DE DK ES FI GB HU JP KP KR KZ LK LU MG MN MW NL NO NZ PL PT RO RU SD SE SK UA US VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1993912467

Country of ref document: EP

Ref document number: 2139220

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 1019940704813

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 08360732

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1993912467

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWG Wipo information: grant in national office

Ref document number: 1993912467

Country of ref document: EP