WO1991009978A1 - Procede de conversion des dechets en produits utiles - Google Patents

Procede de conversion des dechets en produits utiles Download PDF

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Publication number
WO1991009978A1
WO1991009978A1 PCT/CA1990/000454 CA9000454W WO9109978A1 WO 1991009978 A1 WO1991009978 A1 WO 1991009978A1 CA 9000454 W CA9000454 W CA 9000454W WO 9109978 A1 WO9109978 A1 WO 9109978A1
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WO
WIPO (PCT)
Prior art keywords
dross
residue
solution
product
process according
Prior art date
Application number
PCT/CA1990/000454
Other languages
English (en)
Inventor
Gaetan Chauvette
Frank M. Kimmerle
Roger Roussel
Original Assignee
Alcan International 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 Alcan International Limited filed Critical Alcan International Limited
Publication of WO1991009978A1 publication Critical patent/WO1991009978A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/0015—Obtaining aluminium by wet processes
    • C22B21/0023—Obtaining aluminium by wet processes from waste materials
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C1/00—Ammonia; Compounds thereof
    • C01C1/02—Preparation, purification or separation of ammonia
    • C01C1/04—Preparation of ammonia by synthesis in the gas phase
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
    • C01F7/06—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process
    • C01F7/0693—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals or waste-like raw materials with alkali hydroxide, e.g. leaching of bauxite according to the Bayer process from waste-like raw materials, e.g. fly ash or Bayer calcination dust
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/0007—Preliminary treatment of ores or scrap or any other metal source
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/0038—Obtaining aluminium by other processes
    • C22B21/0069—Obtaining aluminium by other processes from scrap, skimmings or any secondary source aluminium, e.g. recovery of alloy constituents
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/04—Working-up slag
    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • This invention relates to a process for converting dross residues to useful products.
  • Dross is a material which forms on the surface of molten aluminum or aluminum alloys during remelting and metal holding and handling operations when the molten metal is in contact with a reactive atmosphere.
  • Dross normally consists of metal oxides and nitrides and a considerable quantity of molten free (unreacted) metal.
  • dross residue dross residue
  • the dumping of dross in this manner has recently come to be regarded as environmentally unacceptable because harmful chemicals may leach out of the dross into ground and surface water and thus cause widespread pollution.
  • the reaction is performed in the liquid phase and under sufficient agitation to ensure particle-to-particle attrition to break the protective aluminum hydroxide film which forms about the aluminum metal contaminant particles, thereby achieving substantially complete oxidation of the aluminum metal contaminant to aluminum oxide trihydrate.
  • the reaction is aimed at dross residues which still contain a relatively large amount of metallic aluminum and the reaction is concerned primarily with the reaction of this metallic component.
  • An object of the present invention is thus to provide a process for treating aluminum nitride-containing dross which contains only a small or no metallic component in order to convert the dross into commercially desirable products and/or to avoid environmental pollution.
  • a process for converting aluminum nitride-containing dross residue into ammonia-containing and alumina-containing products which comprises partially digesting said aluminum nitride-containing dross residue having a content of AIN of at least 5 wt % and no more than about 10 wt % of metallic aluminum with a solution having a pH of 7 or more to solubilize about 10-50 wt % of said residue and to produce an ammonia-containing reaction product, a residual solution and a solid residue; and separating said ammonia-containing reaction product from said solid residue and residual solution.
  • ammonia-containing reaction product and the solid residue can be collected and optionally further treated or reacted to produce commercially valuable end products.
  • the invention thus provides a way of converting aluminum nitride-containing dross residues, and especially plasma dross residues, into useful products, thus avoiding the need for disposal and producing an economic return.
  • the accompanying drawing is a block diagram showing the steps of a basic form of one aspect of the process of the invention and also two optional additional treatment processes.
  • the basis of the present invention is the partial digestion of the aluminum nitride-containing dross residue with a solution having a pH of 7 or more to produce at least an ammonia-containing product and a solid residue.
  • the dross residue must contain at least 5 wt % of aluminum nitride and no more than 10 wt % of metallic aluminum. Drosses with larger amounts of metallic aluminum generate large quantities of unwanted hydrogen in violent reactions when digested and drosses with smaller amounts of aluminum nitride generate insufficient quantities of the desired ammonia.
  • the dross residue should contain at least about 10 wt % AIN and most preferably at least about 25 wt % AIN and preferably only 2 wt% of Al or less.
  • Dross treated by the plasma process indicated above has suitable contents of aluminum nitride and metallic aluminum and is the preferred type of dross residue and has the advantage (in terms of cost, convenience and wear and tear on machinery) that it can usually be used in the process of the invention without intermediate treatment steps, such as grinding to reduce the particle size; however, dross residues from other sources having the required composition may be employed, if desired.
  • Dross which has been cooled rapidly to give particles having a size of 100% -20 Tyler mesh is particularly preferred. Dross which has been cooled slowly may produce sintered lumps which are not very suitable.
  • the digestion should be carried out in such conditions that about 10 to 50 wt % of the residue is solubilized.
  • the aluminum nitride in the dross is converted to ammonia (or an ammonium- containing product) and either a soluble product (if the pH is greater than 7) or an aluminum hydroxide precipitate (if a neutral solution is used) .
  • ammonia or an ammonium- containing product
  • a soluble product if the pH is greater than 7
  • an aluminum hydroxide precipitate if a neutral solution is used
  • This digestion step accomplishes two things; firstly
  • SUBSTITUTE SHEET ammonia is produced and may be collected and liquefied or reacted with an acid to produce a soluble or insoluble salt.
  • Ammonia and ammonium salts are valuable products and can be used as fertilizers and in industry.
  • a useful aluminum trihydrate precipitate is formed (digestion in neutral solutions) or an aluminate solution is obtained (digestion in alkaline solutions) which can be used for the purposes outlined below.
  • dross residues i.e. oxides of aluminum and other metals (e.g. Mg present in drosses from Al/Mg alloys) are generally not digested in mild conditions and remain as a solid residue. However, this solid residue can be used for commercial purposes as will be indicated later.
  • a preferred additional aspect of the invention is based on the surprising discovery that digestion of dross residue in caustic alkali under harsh conditions results in the dissolution of a large component of the dross previously thought to be insoluble. In such conditions, it appears that a proportion of the aluminum and other metal oxides in the dross dissolve to form soluble aluminates.
  • the digestion under caustic conditions can be carried out separately from the AIN hydrolysis step mentioned above but the two steps are usually carried out simultaneously since the AIN hydrolysis takes place under the harsh and caustic conditions as well as under the mild conditions.
  • the conditions required for the digestion of otherwise insoluble fractions of the dross residue are usually as follows.
  • the dross residue is normally heated in an autoclave or similar pressure reactor to a temperature up to about 325'C, preferably 50 - 300°C and usually 100 - 225°C, in the presence of a solution containing a caustic alkali (preferable NaOH for economy, although KOH or LiOH could also be used) .
  • a particularly preferred solution is one containing 50 - 200 g/1 of NaOH (expressed as Na 2 C0 3 ) .
  • the solutions are normally aqueous but could conceivably be organic (e.g. in alcohol or acetone) .
  • Autogenous pressure is preferably generated since the reactor is closed and this pressure varies according to the reaction temperature employed.
  • the autoclave is provided with a safety valve set at a pressure slightly higher than the vapour pressure of water at the intended digestion temperature.
  • the vapour pressure of water is 114 psi and the safety valve is set at about 150 psi.
  • the vapour pressure is 225 psi and the valve is set at 275 psi.
  • Other suitable pressures are apparent from vapour pressure tables.
  • the reaction mixture may be subjected to agitation to accelerate the solubilization.
  • the time required for the digestion step varies according to the size of the charge of the dross residue and its composition, but the digestion is normally complete within a few hours.
  • the optimum ratio of caustic solution to dross residue charge also varies, but in general it can be said that the greater the amount of the
  • the aluminate solution is normally separated from the insoluble fraction e.g. by filtration with a filter press or the like or by means of any other solid/liquid separator.
  • the aluminate solution and the insoluble fraction (together with any ammonia or ammonium reaction product that may have been collected) are then used, sold, converted to other products or (in the case of the insoluble fraction) even disposed of by dumping since the product is non-polluting.
  • the caustic aluminate solution several treatments are possible. Firstly, the aluminate solution may be used in the conventional Bayer process as "Bayer liquor" for the production of alumina.
  • so-called aluminum trihydrate (aluminum trihydroxide) can be precipitated either by cooling the caustic solution, by diluting the caustic solution with water or by a combination of the two. Seed crystals of Al(OH) 3 are generally added to the liquid to promote the precipitation of the solid.
  • the trihydrate produced in this way is very white and is thus a valuable product. It appears that traces of iron and organics responsible for red and yellow hydrate products are either not present in the original dross residue (although this depends on its origin) or, if present, are not solubilized in the caustic digestion process.
  • the aluminate solutions produced by the invention generally do not contain ions, such as ions of Ca, Fe, P and Mg, that slow down the precipitation of the hydrate, nor "poisons” such as sugars, gum arabic and other organics that often contaminate other hydrate products.
  • the solution containing the aluminate should contain less than about 0.1 wt % of dissolved organic carbon and substantially no suspended colloidal iron in order to produce a very white trihydrate product. The solution remaining after the precipitation of the trihydrate can be recycled to the caustic digestion step, if desired.
  • the aluminate in the solution resulting from the caustic digestion step can be converted to other useful chemicals, such as aluminum silicate by the addition of sodium silicate or to zeolites by the addition of Si0 2 , etc.
  • the aluminate can be obtained as a solid product simply by evaporating the water from the solution.
  • Other possible uses of the aluminate solution no doubt exist.
  • the insoluble fraction remaining after the digestion is usually washed to remove traces of alkali and other soluble compounds and is then dried. If the solid contains hydroxide, it may be desirable to calcine the product to produce the corresponding oxide.
  • the product can then be used as such as a refractory precursor or can be treated (e.g. by melting) to form a refractory product such as a rock wool.
  • compositions of dross residues vary widely even when the residues come from the same type of dross treatment process, and so it is difficult to give indications of the proportions of the solid that can be solubilized. However, it is not unusual to be able to dissolve about 27% by weight of plasma dross residue by the mild hydrolysis and about 48% by weight in total following the caustic digestion step.
  • the process of the invention can be operated continuously or batchwise. If preliminary hydrolysation is employed, this step is quite easily made continuous.
  • the caustic digestion step can be made continuous by the use of continuous autoclaves.
  • Plasma dross residue 10 and caustic sodium hydroxide solution 11 are introduced into a digester 12 to bring about partial digestion of the residue 10.
  • ammonia 13 is evolved and removed from the digester 10 12 along with traces of hydrogen and methane generally formed as by-products.
  • the contents of the digester 12, i.e. and aluminate solution and a solid residue, are passed to a solid/liquid separator 14 where the solid 15 is separated from the liquid 16.
  • the resulting solid 15 product 15 generally contains alumina, magnesium oxide and magnesium spinel.
  • the liquid product 16 contains sodium hydroxide and aluminate.
  • the aluminate solution can be converted to solid A1(0H) 3 or to a zeolite.
  • solid Al(OH) 3 the liquid is transferred to a digester 17 where seed crystals 18 of Al(OH) 3 are added and the liquid is cooled.
  • the resulting suspension is then transferred to a solid/liquid separator 19 for removal of the A1(0H) 3 solid 20.
  • the remaining solution 21 of sodium hydroxide and 5 unprecipitated aluminate is then recycled to the feed to digester 12.
  • the liquid product 16 is transferred to a digester 22 to which solid Si0 2 23 is also added, preferably a source of soluble silica such as 0 silica fumes or kaolinite.
  • a solid zeolite precipitate is formed and the resulting suspension is transferred to a solid/liquid separator 24.
  • a solid zeolite product 25 is obtained and the remaining liquid 26 can be recirculated to the digester 12 for use in the initial digestion. 5
  • the invention is described in more detail with reference to the Examples given below.
  • Plasma dross residues were submitted to tests for the determination of available and extractable alumina (available alumina means the portion of dross which can be solubilized under mild alkaline conditions and extractable. alumina means the total amount of dross that can be solubilized under both mild conditions and caustic digestion at high temperature and pressure) .
  • available alumina means the portion of dross which can be solubilized under mild alkaline conditions and extractable. alumina means the total amount of dross that can be solubilized under both mild conditions and caustic digestion at high temperature and pressure
  • the tests involved placing the dross in a 70 ml closed bomb with a concentrated caustic alkali solution and heating the contents under pressure. The results are shown in Table 1 below.
  • the invention can be applied to the utilization of dross residues which are currently discarded as waste in order to avoid environmental pollution and to create an economic return and valuable products.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Inorganic Chemistry (AREA)
  • Analytical Chemistry (AREA)
  • Processing Of Solid Wastes (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Abstract

Procédé de conversion des déchets résiduels ayant une teneur en nitrure d'aliminium d'au moins 5 % en poids et une teneur en aluminium métallique ne dépassant pas 10 % en poids (en particulier les déchets résiduels de plasma) en produits utiles. Ledit précédé consiste à traiter les déchets résiduels avec une solution ayant un pH égal ou supérieur à 7, la réaction à des valeurs de pH alcalines étant: AlN + 4H2O ← + Al(OH)3 + NH4+ + OH- suivi par : Al(OH)¿3 + OH?- ← Al¿2?O?- + 2H¿2O et NH4+ + OH- ← NH¿3? $(1, 3)$ + H2. Le traitement initial des déchets résiduels peut avoir lieu dans des conditions douces afin de produire de l'ammoniaque à partir du nitrure. L'ammoniaque peut ensuite être recueilli comme produit utile ou converti en d'autres produits utiles tels que les sels d'ammonium. Dans des conditions plus sévères, par ex. une température et une pression élevées avec des alcalis caustiques, une part considérable des déchets résiduels se dissout pour former une solution d'aluminate de métal alcalin qui est elle-même un produit utile (elle peut, par ex. être utilisée dans le procédé Bayer) ou peut être convertie en d'autres produits utiles tel que le trihydrate d'aluminium. Une partie des déchets résiduels reste normalement non dissoute et peut également constituer un produit utile, par ex. un précurseur réfractaire, ou peut jetée dans un lieu de décharge puisqu'elle est non polluante.
PCT/CA1990/000454 1989-12-27 1990-12-24 Procede de conversion des dechets en produits utiles WO1991009978A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US45796689A 1989-12-27 1989-12-27
US457,966 1989-12-27
US52939090A 1990-05-29 1990-05-29
US529,390 1990-05-29

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0576416A1 (fr) * 1992-06-17 1993-12-29 Waagner-Biro Aktiengesellschaft Procédé de production de l'aluminium
EP0576254A2 (fr) * 1992-06-22 1993-12-29 Plasma Processing Corporation Produit réactif non-métallique récupéré de crasses
WO1994012434A1 (fr) * 1992-12-01 1994-06-09 Alcan International Limited Procede de transformation de residus de crasse d'aluminium en produits utiles
EP1167556A2 (fr) * 2000-06-28 2002-01-02 Michael Dipl.-Ing. Dr. Techn. Kostjak Procédé de récuparation de l'aluminium par lixiviation à partir de déchets alumineux solides
WO2002090255A1 (fr) * 2001-05-03 2002-11-14 Wacker-Chemie Gmbh Procede pour produire de l'energie par production et par mise en reaction de nitrure d'aluminium
WO2011092632A3 (fr) * 2010-01-27 2012-02-23 Bumatech (Pty) Limited Produit aggloméré contenant de l'alumine
US20170009311A1 (en) * 2014-02-06 2017-01-12 Kabushiki Kaisha Kobe Seiko Sho ( Kobe Steel, Ltd. ) Secondary material for steel refining
CN109365473A (zh) * 2018-10-17 2019-02-22 郑州中科新兴产业技术研究院 一种混联法实现二次铝灰脱氟及资源化的方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE235300C (fr) *
FR427110A (fr) * 1910-05-19 1911-07-27 Ottokar Serpek Procédé de fabrication d'alumine pure à l'aide de nitrure d'aluminium
GB552583A (en) * 1941-09-19 1943-04-15 Felix Singer Extraction of aluminium oxide
US4252776A (en) * 1979-03-29 1981-02-24 Imperial West Chemical Company Aluminum dross processing
EP0097892A1 (fr) * 1982-06-28 1984-01-11 Henkel Kommanditgesellschaft auf Aktien Procédé de décomposition hydrothermique de déchets chimiques et résidus à grande teneur en oxydes d'aluminium calcinés
US4434142A (en) * 1982-09-28 1984-02-28 Imperial West Chemical Company Method for treatment of aluminum dross oxides
JPS62278120A (ja) * 1986-05-27 1987-12-03 Hiroshi Matsuno アルミニウム滓の処理方法
JPS63170215A (ja) * 1987-01-06 1988-07-14 Nichijiyuu Res Center:Kk アルミニウムドロスの造粒方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE235300C (fr) *
FR427110A (fr) * 1910-05-19 1911-07-27 Ottokar Serpek Procédé de fabrication d'alumine pure à l'aide de nitrure d'aluminium
GB552583A (en) * 1941-09-19 1943-04-15 Felix Singer Extraction of aluminium oxide
US4252776A (en) * 1979-03-29 1981-02-24 Imperial West Chemical Company Aluminum dross processing
EP0097892A1 (fr) * 1982-06-28 1984-01-11 Henkel Kommanditgesellschaft auf Aktien Procédé de décomposition hydrothermique de déchets chimiques et résidus à grande teneur en oxydes d'aluminium calcinés
US4434142A (en) * 1982-09-28 1984-02-28 Imperial West Chemical Company Method for treatment of aluminum dross oxides
JPS62278120A (ja) * 1986-05-27 1987-12-03 Hiroshi Matsuno アルミニウム滓の処理方法
JPS63170215A (ja) * 1987-01-06 1988-07-14 Nichijiyuu Res Center:Kk アルミニウムドロスの造粒方法

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Disposal of Industrial Wasdte Materials, Conference at Sheffield, April 1956, Society of Chemical Industry, plc., F.H. Smith: "The recovery of aluminium from waste products", pages 67-74 *
Patent Abstracts of Japan, volume 12, no. 446 (C-546), 24 November 1988; & JP-A-63170215 (NICHIJIYUU RES. CENTER), 14 July 1988 *
Patent Abstracts og Japan, volume 12, no. 172 (C-497), 21 May 1988; & JP-A-62278120 (HIROSHI MATSUNO et al.), 3 December 1987 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0576416A1 (fr) * 1992-06-17 1993-12-29 Waagner-Biro Aktiengesellschaft Procédé de production de l'aluminium
EP0576254A2 (fr) * 1992-06-22 1993-12-29 Plasma Processing Corporation Produit réactif non-métallique récupéré de crasses
EP0576254A3 (fr) * 1992-06-22 1994-04-06 Plasma Processing Corp
AU671121B2 (en) * 1992-06-22 1996-08-15 Plasma Processing Corporation Reactive non-metallic product recovered from dross
WO1994012434A1 (fr) * 1992-12-01 1994-06-09 Alcan International Limited Procede de transformation de residus de crasse d'aluminium en produits utiles
EP1167556A3 (fr) * 2000-06-28 2002-09-25 Michael Dipl.-Ing. Dr. Techn. Kostjak Procédé de récuparation de l'aluminium par lixiviation à partir de déchets alumineux solides
EP1167556A2 (fr) * 2000-06-28 2002-01-02 Michael Dipl.-Ing. Dr. Techn. Kostjak Procédé de récuparation de l'aluminium par lixiviation à partir de déchets alumineux solides
WO2002090255A1 (fr) * 2001-05-03 2002-11-14 Wacker-Chemie Gmbh Procede pour produire de l'energie par production et par mise en reaction de nitrure d'aluminium
WO2011092632A3 (fr) * 2010-01-27 2012-02-23 Bumatech (Pty) Limited Produit aggloméré contenant de l'alumine
US9051187B2 (en) 2010-01-27 2015-06-09 Bumatech (Pty) Limited Agglomerated alumina containing product
US20170009311A1 (en) * 2014-02-06 2017-01-12 Kabushiki Kaisha Kobe Seiko Sho ( Kobe Steel, Ltd. ) Secondary material for steel refining
CN109365473A (zh) * 2018-10-17 2019-02-22 郑州中科新兴产业技术研究院 一种混联法实现二次铝灰脱氟及资源化的方法
CN109365473B (zh) * 2018-10-17 2020-03-17 郑州中科新兴产业技术研究院 一种混联法实现二次铝灰脱氟及资源化的方法

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