[go: up one dir, main page]

WO2025076848A1 - 利用铝灰制备氧化铝的工艺及窑炉 - Google Patents

利用铝灰制备氧化铝的工艺及窑炉 Download PDF

Info

Publication number
WO2025076848A1
WO2025076848A1 PCT/CN2023/124628 CN2023124628W WO2025076848A1 WO 2025076848 A1 WO2025076848 A1 WO 2025076848A1 CN 2023124628 W CN2023124628 W CN 2023124628W WO 2025076848 A1 WO2025076848 A1 WO 2025076848A1
Authority
WO
WIPO (PCT)
Prior art keywords
oxygen
kiln
aluminum
flame
aluminum ash
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.)
Pending
Application number
PCT/CN2023/124628
Other languages
English (en)
French (fr)
Inventor
陈志明
陈文军
刘铠
刘岳
刘倩
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.)
Zibo Jingcheng New Material Co Ltd
Original Assignee
Zibo Jingcheng New Material Co 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
Application filed by Zibo Jingcheng New Material Co Ltd filed Critical Zibo Jingcheng New Material Co Ltd
Priority to KR1020247032847A priority Critical patent/KR20250054222A/ko
Priority to PCT/CN2023/124628 priority patent/WO2025076848A1/zh
Priority to TW113121168A priority patent/TWI900050B/zh
Publication of WO2025076848A1 publication Critical patent/WO2025076848A1/zh
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • C01F7/42—Preparation of aluminium oxide or hydroxide from metallic aluminium, e.g. by oxidation
    • 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
    • C01F7/30—Preparation of aluminium oxide or hydroxide by thermal decomposition or by hydrolysis or oxidation of aluminium compounds
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0033—Heating elements or systems using burners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/16—Introducing a fluid jet or current into the charge
    • F27D2003/162—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel
    • F27D2003/163—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel the fluid being an oxidant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0033—Heating elements or systems using burners
    • F27D2099/0053—Burner fed with preheated gases
    • F27D2099/0056—Oxidant
    • 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
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies

Definitions

  • the invention relates to a process for preparing aluminum oxide by utilizing aluminum ash and a kiln used in the process, belonging to the technical field of aluminum ash processing.
  • Aluminum ash is solid waste in the aluminum industry. According to the source and the content of metallic aluminum, aluminum ash can be divided into primary aluminum ash, secondary aluminum ash, environmental ash (i.e. aluminum ash dust removal ash generated in the process of processing primary aluminum ash, secondary aluminum ash and other recycled aluminum production) and another type of aluminum ash generated by the processing and manufacturing of metal aluminum products.
  • Primary aluminum ash is toxic and harmful solid waste generated in the production process of aluminum industry such as electrolytic aluminum or cast aluminum.
  • main components are metallic aluminum, Al 2 O 3 , AlN, fluoride and other components (the composition of aluminum ash from different sources will vary), and the aluminum content is relatively high; secondary aluminum ash is the residue after the extraction of metallic aluminum from primary aluminum ash or other waste aluminum slag, with low metallic aluminum content and relatively complex composition; aluminum ash generated by the processing and manufacturing of metal aluminum products contains a high amount of metallic aluminum.
  • Aluminum ash is reactive and toxic - its reactivity comes from the metallic aluminum, aluminum nitride and aluminum carbide in the aluminum ash, which produce toxic and harmful gases such as hydrogen, ammonia and methane when in contact with water. Its toxicity mainly comes from the fluorides in the production process. Therefore, it has a high environmental risk. At present, many countries, including China, have included aluminum ash in the list of hazardous wastes, requiring that aluminum ash must be harmlessly treated or recycled, and cannot be discharged or dumped at will.
  • the primary aluminum ash contains a large amount of metallic aluminum
  • many technologies have been developed at home and abroad to recover the metallic aluminum in the aluminum ash, such as the commonly used ash roasting method, rotary furnace method, pressing method, electrostatic separation method, ball mill screening method, etc.
  • Some processes for preparing alumina from aluminum ash are in the research and development stage, such as the invention patent entitled “A method for preparing alumina from aluminum ash slag" with publication number CN106745130A, which discloses a process for preparing alumina by acid method, and the invention patent entitled “A method for preparing alumina from aluminum ash with resource utilization” with publication number CN115321566A, which discloses a process for preparing alumina by alkali smelting method, etc. Most of these processes use acid leaching, alkali leaching and other methods to obtain aluminum ions, and then obtain the final product alumina through subsequent reactions and treatments.
  • the technical problem to be solved by the present invention is: to overcome the deficiencies in the prior art and provide a process for preparing alumina by full oxygen combustion of aluminum ash, which has simple process steps, low cost and energy consumption and is suitable for industrial application; and at the same time, a kiln used in the process is provided.
  • the process for preparing alumina from aluminum ash described in the present invention first raises the temperature in the kiln cavity to 800-1600°C, then introduces the aluminum ash into the kiln to perform full oxygen combustion at high temperature, introduces excess oxygen during the full oxygen combustion process to obtain finished alumina, and the exhaust gas generated during the full oxygen combustion process is discharged from the kiln cavity and then subjected to environmental protection treatment (discharged after passing the environmental protection treatment).
  • the process steps of the present invention are simple. After the temperature in the furnace chamber of the kiln is raised to the required temperature (the temperature in the furnace chamber reaches at least 800°C, and the specific temperature range is determined according to the composition of the aluminum ash raw material), the aluminum ash raw material is introduced into the kiln for high-temperature full oxygen combustion, so that the metallic aluminum contained in the aluminum ash can be fully oxidized to finally obtain finished alumina. At the same time, the toxic fluoride in the aluminum ash is decomposed, and the waste gases such as fluorine gas, sulfur dioxide, nitrogen monoxide, nitrogen dioxide, etc.
  • the flame temperature and heating efficiency can be increased, thereby improving the energy utilization rate.
  • the use of full oxygen combustion can make the flame temperature as high as 1800°C or more.
  • the temperature in the kiln is generally controlled below 1600°C, thereby improving the heating efficiency.
  • the required finished alumina can usually be obtained in 1-5 hours, and the flue gas volume can be greatly reduced, the heat loss of exhaust gas can be reduced, and the overall energy consumption is significantly reduced.
  • aluminum ash contains metallic aluminum
  • metallic aluminum will react violently with oxygen and burn when exposed to open flames at high temperatures. It can be used as both a raw material and a fuel. That is to say, when the aluminum ash in the kiln burns, some or all of the fuel pipelines can be closed and the metallic aluminum in the aluminum ash itself can be used as fuel. A large amount of heat is released during the combustion process, which further improves energy utilization while reducing fuel costs.
  • Alumina is a basic material with a wide range of uses.
  • low-grade alumina can be used in building ceramic blanks to change the structure of the ceramic blanks, increase aluminum, whiten and strengthen.
  • Medium- and high-grade alumina can be used as medium- and high-grade medium-aluminum balls, high-aluminum balls, medium- and high-grade refractory materials, and functional ceramics.
  • the aluminum ash of the present invention can be in powder or granular form.
  • the actual process methods used are different depending on the state of the aluminum ash. The following description is given:
  • All aluminum ash powder can be fed into the furnace cavity of the kiln through the flame-jet oxygen blowing port.
  • the aluminum ash powder contacts with the flame sprayed from the flame-jet oxygen blowing port and burns. If the content of metallic aluminum in the aluminum ash is high, a small amount of fuel can be introduced after the aluminum ash powder burns, or only oxygen can be supplied without introducing fuel, and metallic aluminum can be used as fuel;
  • part of the aluminum ash powder can be fed into the furnace cavity through the flame-spraying oxygen blowing port and the other part through the feed port.
  • the aluminum ash In order to make the aluminum ash react fully and evenly and improve the quality of alumina, the aluminum ash can be crushed, ball-milled, and sieved to obtain aluminum ash powder with uniform particle size.
  • the aluminum ash powder introduced into the kiln through the flame-spraying and oxygen-blowing port first contacts with the combustion flame sprayed from the burner in the flame-spraying and oxygen-blowing port before entering the kiln cavity to achieve pre-combustion (in this process, the aluminum ash powder and the combustion flame can fully contact and mix to achieve a good pre-combustion effect), and then the aluminum ash powder is transported to the kiln cavity along with the burning flame.
  • the exhaust gas discharged from the furnace cavity of the kiln is subjected to one or more stages of sedimentation, and the alumina in the exhaust gas is recovered to improve the final yield of alumina. Further preferably, before and/or during the first stage of sedimentation of the exhaust gas discharged from the furnace cavity of the kiln, secondary full oxygen combustion is carried out to react the unreacted metallic aluminum in the exhaust gas to obtain alumina, which is then recovered.
  • the aluminum ash particles can be directly added into the furnace cavity of the kiln through the feed port.
  • the aluminum ash particles in the present invention can be prepared by the following method: firstly crushing, ball milling, screening, and then granulating the aluminum ash to obtain aluminum ash particles with uniform particle size, ensuring that the aluminum ash particles react fully and evenly, thereby improving the quality of alumina.
  • oxygen is added to the reaction zone of the kiln cavity.
  • a portion of the oxygen is added separately, rather than all the oxygen being introduced into the kiln during the burner combustion process.
  • This has the following two main effects: first, it can avoid the problem of uneven material combustion caused by concentrated oxygen supply at a local position, and second, it can achieve a sufficient and uniform supply of oxygen in the reaction zone, so that the quality of the final alumina product is more uniform.
  • This preferred solution is applicable to both aluminum ash powder and aluminum ash particles.
  • the kiln used in the process of the present invention adopts the following structure: the furnace body is a vertical structure, the upper part of the furnace body is provided with a feeding structure, a plurality of flame spraying and oxygen blowing ports are provided on the furnace wall, burners are installed at the flame spraying and oxygen blowing ports, fuel and oxygen are mixed and burned in the burner, the lower part of the furnace body is provided with a discharge port, a discharge device with a controllable discharge speed is installed at the discharge port, and an exhaust passage is provided at the upper part of the furnace body.
  • the burner When in use, turn on the burner, so that the fuel and oxygen react in the burner and spray the combustion flame into the furnace cavity.
  • the temperature in the furnace cavity reaches the reaction temperature, the aluminum ash is introduced into the furnace cavity of the kiln through the feeding structure, and the aluminum ash is fully oxygen-burned under the high-temperature flame.
  • the kiln in the present invention is specially designed as a vertical structure, so that the aluminum ash will automatically descend by its own weight while fully oxygen-burning, and the aluminum ash descends under the action of the discharging device.
  • the metal aluminum and other substances in the aluminum ash can be fully reacted, and the aluminum oxide obtained by the reaction descends to the lower discharge port, gradually cools during the descent and discharging process, and finally the obtained aluminum oxide is transported to the warehouse.
  • the fluorine gas, sulfur dioxide, nitric oxide, nitrogen dioxide and other gases generated during the full oxygen combustion process are introduced into conventional desulfurization, denitrification, defluorination and other equipment through the exhaust channel for environmental protection treatment, and then discharged after meeting the emission standards.
  • the discharging device in the present invention can adopt the rotating discharging tray used in the conventional coal gasifier slag removal process. Since it is a conventional discharging structure, it will not be described in detail here.
  • the feed structure of the present invention can be a material injection pipe connected to the flame-spraying oxygen blowing port, or a feed port set on the furnace body.
  • the aluminum ash When the aluminum ash is in granular form, the aluminum ash particles are directly added into the furnace cavity through the upper feed port, contacted with the combustion flame and subjected to full oxygen combustion.
  • the aluminum ash When the aluminum ash is in powder form, the aluminum ash powder can be all introduced into the furnace cavity through the material injection pipe, or part of it can be introduced into the furnace cavity through the material injection pipe and the other part through the feed port for full oxygen combustion.
  • the aluminum ash powder is transported in the burning flame, which can avoid deflagration or explosion caused by sudden ignition of the aluminum ash powder.
  • the flame-spraying oxygen blowing port of the present invention may not be connected to a material injection pipe.
  • the flame-spraying oxygen blowing port is used to provide a combustion flame for the full oxygen combustion of aluminum ash (fuel and oxygen in the burner are mixed and burned) or only to supplement sufficient oxygen for the full oxygen combustion of aluminum ash (the fuel pipeline in the burner is closed, and oxygen is only supplied to the furnace chamber through the oxygen pipeline).
  • the flame-spraying oxygen blowing port is connected to a material injection pipe can be flexibly designed according to the actual process.
  • the spray port of the material injection pipe and the flame nozzle of the burner are both located at the front inlet position of the flame and oxygen blowing port, and a pre-combustion chamber is formed in the middle and rear part of the flame and oxygen blowing port (i.e., the position close to the furnace cavity), so that the aluminum ash powder sprayed from the material injection pipe and the combustion flame of the burner can be mixed and pre-combusted in the space of the pre-combustion chamber, and then enter the high temperature area of the kiln cavity for combustion reaction.
  • the angle ⁇ is preferably 5°-120°.
  • the flame spraying and oxygen blowing ports are arranged in one or more rows; when multiple rows are arranged, the upper and lower flame spraying and oxygen blowing ports of two adjacent rows are aligned or staggered.
  • an oxygen blowing pipe for passing oxygen upward is provided at the bottom of the furnace body, and the top of the oxygen blowing pipe has an elbow and the pipe mouth faces downward.
  • Oxygen is added to the furnace chamber from bottom to top through the oxygen blowing pipe, so that the metal aluminum in the aluminum ash reacts fully and the yield of alumina is increased.
  • the design of the elbow at the top of the oxygen blowing pipe can effectively prevent the downward powder from clogging the pipe mouth of the oxygen blowing pipe or flowing back into the oxygen blowing pipe when the oxygen flow rate is small.
  • the exhaust channel is connected to one or more sedimentation chambers at the rear, and a product discharge port is provided at the bottom of each sedimentation chamber, and a waste gas port is provided at the top of the last chamber.
  • the alumina that goes up to the exhaust channel with the high-temperature exhaust gas in the furnace chamber can be collected and settled through the sedimentation chamber, and the alumina can be recovered through the product discharge port, thereby improving the final alumina yield.
  • full oxygen burners are installed on the exhaust channel and the sedimentation chamber. In actual use, a small amount of full oxygen burners can be installed on the exhaust channel and the first-stage sedimentation chamber. The main purpose is to fully react the unreacted metallic aluminum discharged into the exhaust channel with the high-temperature exhaust gas, thereby further improving the alumina yield.
  • the process steps described in the present invention are simpler. It only requires passing aluminum ash into a kiln and performing high-temperature full oxygen combustion to fully oxidize the metallic aluminum contained in the aluminum ash, and finally obtain finished alumina.
  • the production cost is low and it is suitable for industrial application.
  • the toxic fluoride in the aluminum ash is decomposed, and the fluorine gas generated by the decomposition is removed through defluorination environmental protection equipment.
  • the full oxygen combustion improves the heating efficiency and energy utilization rate, reduces the heat loss of smoke exhaust, and significantly reduces the overall energy consumption.
  • the metallic aluminum contained in the aluminum ash will burn violently when encountering an open flame at high temperature. It serves as both a raw material and a fuel, and releases a large amount of heat during the combustion process, which can further improve the energy utilization rate while reducing fuel costs.
  • FIG1 is a schematic diagram of the structure of the kiln in the first embodiment
  • FIG2 is a second schematic diagram of the structure of the kiln in the first embodiment
  • FIG3 is one of the structural schematic diagrams of the kiln described in Example 3.
  • FIG4 is a top view of the burner and the material injection pipe in FIG3;
  • FIG. 5 is a second schematic diagram of the structure of the kiln described in the third embodiment.
  • furnace body 2. furnace cavity; 3. flame and oxygen blowing port; 4. burner; 5. reaction zone; 6. finished alumina outlet; 7. discharge device; 8. discharge guide plate; 9. oxygen blowing pipe; 10. elbow; 11. feed port; 12. exhaust channel; 13. material injection pipe; 14. pre-combustion chamber; 15. sedimentation chamber; 16. exhaust gas port; 17. product discharge port; 18. full oxygen burner.
  • the raw material in this embodiment is primary aluminum ash produced during the production of 1 ton of electrolytic aluminum.
  • the main components of the raw material are 12.8% metallic aluminum, 19.2% aluminum nitride, 49.2% aluminum oxide, and 18.8% fluoride-containing salts and other metal oxides.
  • the primary aluminum ash is first pre-treated, i.e. crushed, ball-milled, and screened, and then granulated to obtain aluminum ash particles with uniform particle size.
  • the temperature in the kiln is first raised to 1400°C-1600°C, and then the aluminum ash particles are added to the kiln to perform full oxygen combustion at high temperature. Excess oxygen is introduced during the full oxygen combustion process, and finished alumina is obtained after 4 hours (the alumina prepared in this embodiment is high-temperature alumina and activated alumina, and the discharge rate is controlled according to the needs of the product to control the residence time of the product in the kiln).
  • the fluorine gas, sulfur dioxide, nitrogen monoxide, nitrogen dioxide and other waste gases generated during the full oxygen combustion are discharged from the kiln cavity, they are successively introduced into the SNCR denitrification equipment (high-temperature non-catalytic reduction denitrification), flue gas cooler, wind dust collector, SDS dry desulfurization and defluorination tower, low-pressure pulse bag dust collector, SCR denitrification equipment (selective catalytic reduction denitrification), induced draft fan, wet defluorination tower for environmental protection treatment, and discharged from the chimney after meeting the standards.
  • the SNCR denitrification equipment high-temperature non-catalytic reduction denitrification
  • flue gas cooler wind dust collector
  • SDS dry desulfurization and defluorination tower low-pressure pulse bag dust collector
  • SCR denitrification equipment selective catalytic reduction denitrification
  • induced draft fan wet defluorination tower for environmental protection treatment
  • the kiln used in this embodiment is shown in Figures 1 and 2.
  • the furnace body 1 is a vertical structure.
  • the upper part of the furnace body 1 has a feeding structure.
  • a plurality of flame-spraying and oxygen-blowing ports 3 are provided on the furnace wall.
  • Burners 4 are installed at the flame-spraying and oxygen-blowing ports 3. Fuel and oxygen are mixed and burned in the burner 4.
  • the lower part of the furnace body 1 has a discharge port.
  • a discharge device 7 with a controllable discharge speed is installed at the discharge port.
  • An exhaust passage 12 is provided at the upper part of the furnace body 1.
  • the discharging device 7 adopts the rotating discharging tray used in the conventional gasifier slag discharge process.
  • a downward guiding tower mountain structure is fixed on the rotating discharging tray.
  • the tower mountain is provided with a discharging guide plate 8.
  • the finished alumina outlet 6 is arranged on the circumference of the rotating discharging tray.
  • the discharging guide plate on the tower mountain generates downward pressure to press the powdered alumina out from the bottom of the furnace body.
  • the feeding structure is a feeding port 11 arranged at the top of the furnace body 1. Aluminum ash particles are directly added into the furnace chamber 2 through the upper feeding port 11, contacted with the combustion flame and subjected to full oxygen combustion.
  • a row of flame-spraying oxygen blowing ports 3 are arranged to provide combustion flame for the full oxygen combustion of aluminum ash (the fuel and oxygen in the burner 4 are mixed and burned), or to only supplement sufficient oxygen for the full oxygen combustion of aluminum ash (the fuel pipeline in the burner 4 is closed, and oxygen is only supplied to the furnace chamber 2 through the oxygen pipeline).
  • An oxygen blowing pipe 9 for passing oxygen upward is provided at the bottom of the furnace body 1, and an elbow 10 is provided at the top of the oxygen blowing pipe 9 with the pipe opening facing downward.
  • Oxygen is added from bottom to top into the furnace chamber 2 through the oxygen blowing pipe 9, so that the metal aluminum in the aluminum ash reacts fully and the yield of alumina is increased.
  • the design of the elbow 10 at the top of the oxygen blowing pipe 9 can effectively prevent the downward powder from clogging the pipe opening of the oxygen blowing pipe 9.
  • the burner 4 When in use, turn on the burner 4, so that the fuel and oxygen react in the burner 4 and spray the combustion flame into the furnace chamber 2.
  • the temperature in the furnace chamber 2 reaches 1500°C
  • the aluminum ash particles are introduced into the furnace chamber 2 of the kiln through the feed port 11, and the aluminum ash is fully oxygen-burned under the high-temperature flame.
  • the kiln is designed as a vertical structure.
  • the aluminum ash will automatically descend by its own weight while fully oxygen-burning. Adjust the discharge speed of the rotating discharge tray, and the aluminum ash will slowly descend under the slow discharge action. In this process, the metal aluminum and other substances in the aluminum ash can fully react, and the aluminum oxide obtained by the reaction slowly descends to the discharge port below, gradually cools down during the descending and discharging process, and finally the obtained finished aluminum oxide is transported to the warehouse.
  • the obtained alumina contains: aluminum oxide content of 97.85%, magnesium oxide content of 0.21%, silicon oxide content of 0.48%, sodium oxide content of 0.56%, calcium oxide content of 0.18%, iron oxide content of 0.21%, and other oxides, and no fluorine-containing substances.
  • the finished alumina obtained by this embodiment is a medium-high grade alumina, which can be used for the preparation of high-grade medium-high aluminum balls, high aluminum balls, medium-high grade refractory materials, functional ceramics, etc., so that the primary aluminum ash is more fully utilized.
  • the raw materials used in this embodiment need to be paid a processing fee of 800 yuan to 1000 yuan per ton by the raw material supplier to the processing manufacturer, and the overall process cost is 700 yuan per ton, while the finished alumina obtained by this embodiment is sold at a price of 2200 yuan to 2500 yuan per ton, which has considerable economic benefits and is suitable for industrial applications.
  • the process steps described in this embodiment are simple and the production cost is low. It only needs to pass the aluminum ash into the kiln and carry out high-temperature full oxygen combustion to fully oxidize the metallic aluminum contained in the aluminum ash to finally obtain finished alumina. The waste gas generated in the process is passed into environmental protection equipment for treatment.
  • the primary aluminum ash used in this embodiment contains a large amount of metal aluminum, and the metal aluminum will burn violently in the kiln, serving as both a raw material and a fuel. That is to say, after the metal aluminum in the kiln burns, the fuel pipeline can be closed, and the supply of fuel in the burner 4 can be stopped.
  • the metal aluminum itself is used as fuel, and a large amount of heat is released during its combustion, which improves energy utilization and reduces fuel costs.
  • the raw material in this embodiment is 1 ton of secondary aluminum ash produced by recycled aluminum plants, the main components of which are 3.3% metallic aluminum, 17.2% aluminum nitride, 50.3% aluminum oxide, and 29.2% fluoride-containing salts and other metal oxides.
  • the secondary aluminum ash is crushed, ball-milled, sieved, and then granulated to obtain aluminum ash particles with uniform particle size.
  • the kiln structure used in the process for preparing alumina in this embodiment is the same as that described in the first embodiment, and the process for preparing alumina is also basically the same as that in the first embodiment, except that some process parameters of full oxygen combustion are specifically described below:
  • the temperature in the furnace chamber 2 of the kiln is controlled at 1300° C.-1600° C., and finished alumina is obtained after 3.5 hours.
  • the obtained alumina contained: aluminum oxide content of 77.00%, magnesium oxide content of 7.25%, silicon oxide content of 7.69%, sodium oxide content of 1.33%, calcium oxide content of 1.86%, iron oxide content of 2.63%, and other oxides, and no fluorine-containing substances.
  • the finished alumina obtained by this embodiment is a medium-high grade alumina, which can be used as high-grade medium aluminum balls, substitute bauxite, and preparation of functional ceramics, so that secondary aluminum ash is more fully utilized.
  • the raw material used in this embodiment needs to pay a processing fee of 1,400 yuan to 1,600 yuan per ton to the processing manufacturer, and the overall process cost is 800 yuan per ton, while the finished alumina obtained by this embodiment is sold at 700-900 yuan per ton, and the processing volume of secondary aluminum ash in the market is very large, and the economic benefits are considerable.
  • the raw material in this embodiment is 1 ton of secondary aluminum ash produced by a recycled aluminum plant.
  • the main components of the raw material are 3.3% metallic aluminum, 17.2% aluminum nitride, 50.3% aluminum oxide, and 29.2% fluoride-containing salts and other metal oxides, which is the same as the aluminum ash composition used in Example 2.
  • the kiln structure in this embodiment is different from the structure described in Example 1.
  • the kiln structure used in the process of preparing aluminum oxide in this embodiment is shown in Figures 3-5:
  • the furnace body 1 is a vertical structure, with a feeding structure at the upper part of the furnace body 1, a plurality of flame-spraying and oxygen-blowing ports 3 are arranged on the furnace wall, burners 4 are installed at the flame-spraying and oxygen-blowing ports 3, fuel and oxygen are mixed and burned in the burner 4, a discharge port is provided at the lower part of the furnace body 1, a discharge device 7 with a controllable discharge speed is installed at the discharge port, and an exhaust passage 12 is provided at the upper part of the furnace body 1.
  • the feeding structure includes a material injection pipe 13 connected to the flame-injection oxygen blowing port 3 and a feeding port 11 arranged on the top of the furnace body 1.
  • the aluminum ash powder can be completely introduced into the furnace chamber 2 through the material injection pipe 13, or a part of it can be introduced into the furnace chamber 2 through the material injection pipe 13 and the other part through the feeding port 11 for full oxygen combustion.
  • the flame-spraying oxygen blowing ports 3 are provided in two rows, one above the other, and the two rows of flame-spraying oxygen blowing ports 3 are aligned vertically, wherein: the upper row of flame-spraying oxygen blowing ports 3 is connected to the material injection pipe 13, the jet outlet of the material injection pipe 13 and the flame-spraying port of the burner 4 are both located at the front inlet position of the flame-spraying oxygen blowing ports 3, and the flame-spraying port of the burner 4 and the jet outlet of the material injection pipe 13 form an angle of 30°, so that the aluminum ash powder sprayed from the material injection pipe 13 can be better mixed with the combustion flame, and a pre-combustion chamber 14 is formed in the middle and rear parts of the flame-spraying oxygen blowing ports 3 (i.e., the position close to the furnace chamber 2); the lower row of flame-spraying oxygen blowing ports 3 are not connected to the material injection pipe 13, and only the burner 4 is installed.
  • An oxygen blowing pipe 9 for passing oxygen upward is arranged at the bottom of the furnace body 1.
  • the top of the oxygen blowing pipe 9 is provided with an elbow 10 and the pipe mouth faces downward.
  • the exhaust channel 12 is connected to a four-stage sedimentation chamber 15 at the rear, and the powder in the furnace chamber 2 that goes up to the exhaust channel 12 with the high-temperature exhaust gas can be collected by sedimentation through the sedimentation chamber 15.
  • a product discharge port 17 is provided at the bottom of each stage of the sedimentation chamber 15 to recover the aluminum oxide contained in the powder and improve the final aluminum oxide yield.
  • the sedimentation chamber 15 in this embodiment adopts an up-and-down reciprocating design, and the gas passes through the four-stage sedimentation chamber 15 along an S-shaped path (as shown in FIG. 5 ) to improve the sedimentation effect; an exhaust port 16 is provided at the top of the last stage of the chamber.
  • full oxygen burners 18 are installed in the exhaust channel 12 and on the upper part of the settling chamber 15, respectively, to fully react the unreacted metallic aluminum discharged into the exhaust channel 12 along with the high-temperature exhaust gas, further improving the yield of aluminum oxide.
  • the burner 4 is turned on to make the fuel and oxygen react in the burner 4 and spray the combustion flame into the furnace chamber 2.
  • the temperature in the furnace chamber of the kiln rises to 1500°C
  • the aluminum ash powder is sent into the furnace chamber 2.
  • all the aluminum ash powder is introduced through the material injection pipe 13, and the aluminum ash powder and the combustion flame are contacted and mixed in the pre-combustion chamber 14 to achieve pre-combustion.
  • the aluminum ash powder is transported to the furnace chamber 2 of the kiln along with the combustion flame for full oxygen combustion.
  • the temperature in the furnace chamber 2 of the kiln is controlled at 1400°C-1600°C. Excessive oxygen is introduced during the combustion process to make the metal aluminum in the aluminum ash fully react.
  • the finished alumina is obtained (the finished alumina obtained in this embodiment is high-temperature activated alumina).
  • the finished alumina is discharged from the discharge port under the action of the rotating discharge tray and transported to the warehouse.
  • a part of the powder will go up with the high-temperature airflow and enter the exhaust channel 12 with the exhaust gas.
  • This part of the powder may contain the prepared alumina, unreacted metal aluminum, etc.
  • the unreacted metal aluminum flows through the exhaust channel 12 and the full oxygen burner 18 of the first-stage sedimentation chamber 15, it is fully oxygen-burned to generate alumina, and the up and down reciprocating sedimentation is realized in the four-stage sedimentation chamber 15 to recover the remaining alumina.
  • the fluorine gas, sulfur dioxide, nitrogen monoxide, nitrogen dioxide and other waste gases generated during the entire full oxygen combustion process are successively introduced into the SNCR denitrification equipment (high-temperature non-catalytic reduction denitrification), flue gas cooler, air dust collector, SDS dry desulfurization and defluorination tower, low-pressure pulse bag dust collector, SCR denitrification equipment (selective catalytic reduction denitrification), induced draft fan, wet defluorination tower for environmental protection treatment, and discharged from the chimney after meeting the standards.
  • sufficient oxygen is added to the reaction zone 5 of the kiln cavity 2 through the burner 4 in the second row of flame-spraying oxygen ports 3 and the lower oxygen blowing pipe 9.
  • the finished alumina prepared in this embodiment contains: aluminum oxide content of 78.2%, magnesium oxide content of 7.45%, silicon oxide content of 7.44%, sodium oxide content of 1.56%, calcium oxide content of 1.82%, iron oxide content of 2.39%, and other oxides, and no fluorine-containing substances.
  • the finished alumina obtained by this embodiment is the same as that of the second embodiment, which is medium-high grade alumina and can be used as high-grade medium aluminum balls, a substitute for bauxite, the preparation of functional ceramics, etc., with considerable economic benefits.
  • the raw material in this embodiment is aluminum ash dust ash generated in the production process of 1 ton of recycled secondary aluminum.
  • the main components of the raw material are 1.7% metallic aluminum, 45.6% aluminum oxide, 15.7% aluminum nitride, and 37% fluoride-containing salts and other metal oxides.
  • the kiln structure used in the process of preparing alumina in this embodiment is the same as the structure described in Example 3, and the process method for preparing alumina is also basically the same as Example 3. The only difference lies in some process parameters of full oxygen combustion.
  • the temperature in the kiln cavity 2 is controlled at 1000°C-1200°C, and finished alumina is obtained after 3 hours.
  • the finished alumina obtained in this embodiment contains: 68.5% aluminum oxide, 8.5% magnesium oxide, 11.3% silicon oxide, 2.9% sodium oxide, 4.3% calcium oxide, 3.2% iron oxide, and other oxides, but no fluorine-containing substances.
  • the finished alumina obtained by this embodiment is a medium-grade alumina, which can be used as ordinary medium-alumina balls, substitute bauxite, and the preparation of functional ceramics, so that environmentally friendly ash is more fully utilized.
  • the raw materials used in this embodiment need to be paid a processing fee of 2,000 yuan to 2,400 yuan per ton by the raw material supplier to the processing manufacturer, and the overall process cost is 900 yuan per ton.
  • the finished alumina obtained by this embodiment is sold at a price of 400 yuan to 700 yuan per ton, and the economic benefits are also considerable.
  • the raw material in this embodiment is aluminum ash produced by processing and manufacturing 1 ton of metal aluminum products.
  • the main components of the raw material are 7.4% metal aluminum, 18.3% aluminum nitride, 48.7% aluminum oxide, and 25.6% fluoride-containing salts and other metal oxides.
  • the kiln structure used in the process of preparing alumina in this embodiment is the same as the structure described in Example 3, and the process method for preparing alumina is also basically the same as Example 3. The only difference lies in some process parameters of full oxygen combustion.
  • the temperature in the kiln cavity 2 is controlled at 1400°C-1600°C, and finished alumina is obtained after 4 hours.
  • the finished alumina prepared in this embodiment contains: 85.9% aluminum oxide, 3.63% magnesium oxide, 5.87% silicon oxide, 1.34% sodium oxide, 0.99% calcium oxide, 0.23% iron oxide, and other oxides, but no fluorine-containing substances.
  • the finished alumina obtained by this embodiment is a medium-high grade alumina, which can be used for the preparation of medium-high grade medium-aluminum balls, high-aluminum balls, medium-high grade refractory materials, functional ceramics, etc., so that the aluminum ash produced by the processing and manufacturing of metal aluminum products is more fully utilized.
  • the raw material supplier needs to pay the processing manufacturer a processing fee of 600 yuan to 1,000 yuan per ton, and the overall process cost is 700 yuan per ton, while the finished alumina obtained by this embodiment is sold at a price of 1,400 yuan to 2,000 yuan per ton, which has considerable economic benefits and is suitable for industrial applications.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

本发明属于铝灰处理技术领域，涉及一种利用铝灰制备氧化铝的工艺以及工艺中使用的窑炉。本工艺过程如下：先将窑炉炉腔内温度升至800-1600℃，之后将铝灰通入窑炉，使其在高温下进行全氧燃烧，在全氧燃烧过程中通入过量氧气，得到成品氧化铝，全氧燃烧过程中产生的废气从窑炉炉腔排出后进行环保处理。与现有酸浸、碱浸等方法制备氧化铝工艺相比，本工艺步骤简单，生产成本低，且适于工业化应用；通过全氧燃烧提高了加热效率和能量利用率，降低排烟热损失，整体能耗得到明显降低；铝灰中所含金属铝在高温下遇明火后会发生剧烈燃烧，既作为原料，又作为燃料，燃烧过程中放出大量的热，能够进一步提高能量利用率。

Description

利用铝灰制备氧化铝的工艺及窑炉 技术领域
本发明涉及一种利用铝灰制备氧化铝的工艺以及工艺中使用的窑炉，属于铝灰处理技术领域。
 背景技术
铝灰是铝工业中的固体废弃物，根据来源及金属铝含量的不同，铝灰可分为一次铝灰、二次铝灰、环保灰（即在处理一次铝灰、二次铝灰等回收再生铝生产过程中产生的铝灰除尘灰）以及另外一种金属铝制品加工制造产生的铝灰。一次铝灰是在电解铝或者铸造铝等制铝工业生产过程中产生的有毒有害的固体废弃物，其主要成分为金属铝、Al 2O 3、AlN、氟化物及其他组分（不同来源的铝灰成分会有所差别），含铝量较高；二次铝灰是一次铝灰或其他废渣铝提取金属铝后的残渣，金属铝含量低，成分相对复杂；金属铝制品加工制造产生的铝灰含金属铝量较高。
由于铝灰具有反应性和毒性——其反应性来源于铝灰中的金属铝、氮化铝和碳化铝，遇水分别产生氢气、氨气和甲烷等有毒有害气体，其毒性主要来自生产过程中的氟化物，因此其环境风险较高，目前，包括中国在内的很多国家都已把铝灰纳入危险废物名单，要求必须对铝灰进行无害化处理或者资源化利用，不能随意排放、倾倒。
因一次铝灰中金属铝含量较多，因此国内外开发了很多技术用于回收铝灰中的金属铝，如常用的炒灰法、回转炉法、压榨法、电选法、球磨筛分法等。也有将铝灰与氧化钙（或者石灰石）混合煅烧制备成炼钢精炼剂铝酸钙进行资源化再利用的。
还有部分利用铝灰制备氧化铝的工艺方法正处在研发阶段，如：名称为“一种铝灰渣制备氧化铝的方法”、公开号为CN106745130A的发明专利中公开了一种通过酸法制备氧化铝的工艺，名称为“一种资源化利用铝灰制备氧化铝的方法”、公开号为CN115321566A的发明专利中公开了一种通过碱熔炼法制备氧化铝的工艺，等等。这些大都采用酸浸、碱浸等方法得到含铝离子，再通过后续反应、处理得到最终产品氧化铝，虽然能够实现铝灰的再利用，但工艺过程复杂，酸液、碱液等生产原料成本也很高，同时还带来了工艺废液以及固体废渣（也是危废）等的后续处理的问题，后续处理费用高昂，基于这些问题的存在，目前此类工艺方法依然停留在小规模试验阶段，未能实现工业化应用。
 发明内容
本发明要解决的技术问题是：克服现有技术中的不足，提供一种工艺步骤简单、成本及能耗低且适于工业化应用的利用铝灰全氧燃烧制备氧化铝的工艺；同时提供一种该工艺中使用的窑炉。
本发明所述的利用铝灰制备氧化铝的工艺，先将窑炉炉腔内温度升至800-1600℃，之后将铝灰通入窑炉，使其在高温下进行全氧燃烧，在全氧燃烧过程中通入过量氧气，得到成品氧化铝，全氧燃烧过程中产生的废气从窑炉炉腔排出后进行环保处理（环保处理合格后再排放）。
本发明所述工艺步骤简单，将窑炉炉腔内温度升至所需温度后（炉腔内温度至少达到800℃以上，具体温度范围根据铝灰原料成分来确定），将铝灰原料通入窑炉中进行高温全氧燃烧，即可将铝灰中所含金属铝充分氧化，最终得到成品氧化铝，同时铝灰中的有毒物质氟化物分解，制备氧化铝工艺中产生的氟气、二氧化硫、一氧化氮、二氧化氮等废气通入环保设备（如常规脱硫、脱硝、除尘及脱氟等设备）一一进行处理；由于采用全氧燃烧，因此能够提高火焰温度以及加热效率，进而提高了能量利用率，同时，相比传统空气燃烧，采用全氧燃烧可以使火焰温度高达1800℃以上，为了保护窑炉使用寿命，一般窑炉内温度控制在1600℃以下，从而提高加热效率，通常1-5小时就可以得到所需成品氧化铝，同时能够大幅减少烟气量，降低排烟热损失，整体能耗得到明显降低。另外，因铝灰中含有金属铝，金属铝在高温下遇明火后会与氧气发生剧烈反应燃烧，既作为原料，又作为燃料，也就是说，当窑炉内铝灰燃烧后，可以关闭部分或者全部燃料管路，以铝灰自身的金属铝作为燃料，其燃烧过程中放出大量的热，进一步提高了能量利用率，同时降低燃料成本。
因不同来源的铝灰成分会有所差别，因此通过本发明所述工艺可以得到不同品位的氧化铝，而氧化铝是一种基础材料，其用途非常广泛。如：低品位的氧化铝可以应用在建筑陶瓷坯体改变陶瓷坯体结构，起到增铝、增白、增强。中高品位的氧化铝可以作中高档中铝球、高铝球以及中高档耐火材料、功能陶瓷用。
在实际生产中，还需要根据所需氧化铝的不同性能控制工艺中的温度参数，例如：如需得到活性氧化铝产品，则需要将窑炉内温度控制在1400℃以下；如需得到高温、高纯氧化铝产品，则需要将窑炉内温度控制在1400℃以上至1600℃。
本发明所述铝灰可以呈粉末状或者颗粒状，铝灰状态不同，实际采用的工艺方法也有所区别，现做以下说明：
当铝灰呈粉末状时：
铝灰粉末可以全部通过喷火吹氧口送入窑炉炉腔内，在铝灰粉末通过喷火吹氧口送入窑炉炉腔的过程中，铝灰粉末与喷火吹氧口喷出的火焰接触并燃烧，若铝灰中金属铝的含量较高，在铝灰粉末燃烧后，可通入少量燃料，或者只供氧气、不再通入燃料，以金属铝作燃料即可； 
当然，铝灰粉末也可以一部分通过喷火吹氧口、另一部分通过进料口送入窑炉炉腔内。
需要注意的是：
当一部分铝灰粉末通过进料口送入窑炉炉腔中时，必须要在窑炉炉腔内高温的情况下才可以加料，这样进入窑炉中可燃的粉料瞬间点燃，能够有效避免因积攒大量漂浮的可燃粉料突然性点燃所产生的爆炸事故，为了安全起见，在窑炉炉腔内温度控制在1200℃以上时开始通过进料口慢慢加入铝灰粉末，随温度的升高逐渐提高加料速度。
为了使铝灰能够充分均匀反应，提高氧化铝的质量，可以对铝灰进行破碎、球磨、筛分，得到粒径均匀的铝灰粉末。
优选的，随喷火吹氧口通入窑炉的铝灰粉末，在通入窑炉炉腔之前先与喷火吹氧口中燃烧器喷出的燃烧火焰接触，实现预燃（在该过程中，铝灰粉末与燃烧火焰能够充分接触并混合，达到良好的预燃效果）后，铝灰粉末随燃烧的火焰输送至窑炉炉腔中。
由于窑炉炉腔内温度很高，粉料进入炉腔后，会有一部分随高温气流上行，并可能随废气排出，这部分粉料中可能含有氧化铝以及未反应的金属铝等，因此，在本发明所述工艺中增加以下步骤：将窑炉炉腔排出的废气进行一级或多级沉降，回收废气中的氧化铝，提高最终氧化铝的收率。进一步优选的，窑炉炉腔排出的废气进行一级沉降之前和/或经过一级沉降时，进行二次全氧燃烧，将废气中未反应的金属铝反应得到氧化铝，并进行回收。
当铝灰呈颗粒状时：
铝灰颗粒直接通过进料口加入窑炉炉腔中即可。本发明中的铝灰颗粒可通过以下方式制得：先将铝灰进行破碎、球磨、筛分，之后造粒，得到粒径均匀的铝灰颗粒，确保铝灰颗粒充分均匀反应，提高氧化铝的质量。
优选的，全氧燃烧过程中，向窑炉炉腔的反应区中补入氧气。本优选方案中，将一部分氧气单独补入，而不是将所有氧气都随燃烧器燃烧过程通入窑炉中，主要有以下两方面的作用：一是能够避免因局部位置氧气集中供应所产生的物料燃烧不均匀的问题，二是实现反应区氧气的充分均匀供应，使最终得到的氧化铝产品质量更均匀。本优选方案既适用于铝灰粉末，又适用于铝灰颗粒。
本发明所述工艺中使用的窑炉，采用以下结构：炉体为立式结构，炉体上部具有进料结构，炉壁上设有若干喷火吹氧口，喷火吹氧口处安装燃烧器，燃料与氧气在燃烧器内混合燃烧，炉体下部具有出料口，出料口处安装出料速度可控的出料装置，炉体上部设有排气通道。
使用时，开启燃烧器，使燃料与氧气在燃烧器内反应并向炉腔内喷出燃烧火焰，当炉腔内温度达到反应温度时，将铝灰通过进料结构通入窑炉的炉腔内，铝灰在高温火焰下全氧燃烧。本发明中的窑炉特意设计为立式结构，这样铝灰在全氧燃烧的同时会靠其自重自动下行，在出料装置的作用下铝灰下行，在该过程中，铝灰中的金属铝等物质能够进行充分反应，反应得到的氧化铝下行至下方出料口处，在下行及出料过程中逐渐冷却，最终将得到的氧化铝输送至仓库，全氧燃烧过程中产生的氟气、二氧化硫、一氧化氮、二氧化氮等气体通过排气通道通入常规脱硫、脱硝、脱氟等设备中进行环保处理，达到排放标准后再排放。
本发明中的出料装置可以采用常规煤气发生炉排渣工艺中使用的旋转出料托盘，因其为常规出料结构，此处不再细述。
本发明所述进料结构可以是接入喷火吹氧口中的物料喷进管，也可以是设置在炉体上的进料口。当铝灰呈颗粒状时，铝灰颗粒直接通过上方的进料口加入炉腔内，与燃烧火焰接触并进行全氧燃烧。当铝灰成粉末状时，铝灰粉末可以全部通过物料喷进管通入炉腔中，也可以一部分通过物料喷进管、另一部分通过进料口送入炉腔内，进行全氧燃烧，在燃烧的火焰中输送铝灰粉末，能够避免因铝灰粉末突然性着火所形成的爆燃或者爆炸。
需要说明的是，本发明所述喷火吹氧口处可以不接物料喷进管，此时喷火吹氧口的作用就是为铝灰全氧燃烧提供燃烧火焰（燃烧器中的燃料与氧气混合燃烧）或者仅为铝灰全氧燃烧补充足够氧气（燃烧器中的燃料管路关闭，仅通过氧气管路向炉腔内供应氧气）。喷火吹氧口处是否接物料喷进管可根据实际工艺进行灵活设计。
进一步优选的，物料喷进管的喷出口和燃烧器的喷火口均位于喷火吹氧口的前部进口位置，喷火吹氧口的中后部（即靠近炉腔的位置）形成预燃室，使物料喷进管喷出的铝灰粉末与燃烧器的燃烧火焰在预燃室这一空间内能够混合预燃，之后再进入窑炉炉腔的高温区进行燃烧反应。 
优选的，燃烧器的喷火口与物料喷进管的喷出口之间存在一定的夹角α，使物料喷进管喷出的铝灰粉末与燃烧火焰能够更好的混合预燃。实际设计时，夹角α的度数优选5°-120°。
优选的，喷火吹氧口设置一排或多排；当设置多排时，相邻两排的上下喷火吹氧口对齐或者交错设置。
优选的，炉体底部设有向上通氧的吹氧管，吹氧管顶部具有弯头且管口朝下。通过吹氧管自下而上向炉腔内补充氧气，使铝灰中的金属铝充分反应，提高氧化铝的产量，吹氧管顶部弯头的设计能够有效防止当氧气流量小时下行的粉末堵塞吹氧管管口或者倒灌进吹氧管中。
优选的，排气通道后方连接一级或者多级沉降腔室，每一级沉降腔室的底部设有产品出料口，在最后一级腔室的上部开有废气口。通过沉降腔室能够将炉腔内随高温废气上行至排气通道中的氧化铝进行沉降收集，并通过产品出料口将氧化铝进行回收，提高最终氧化铝的收率。进一步优选的，排气通道以及沉降腔室上安装全氧燃烧器，实际使用时，可以在排气通道以及第一级沉降腔室上安装少量全氧燃烧器，主要目的是将随高温废气排至排气通道中的未反应的金属铝充分反应，进一步提高氧化铝的收率。
有益效果
相比现有酸浸、碱浸等方法制备氧化铝的工艺，本发明所述工艺步骤更为简单，只需将铝灰通入窑炉并进行高温全氧燃烧，即可将铝灰中所含金属铝充分氧化，最终得到成品氧化铝，生产成本低，且适于工业化应用；在高温烧制过程中，铝灰中的有毒物质氟化物被分解，分解生成的氟气通过脱氟环保设备脱除；通过全氧燃烧提高了加热效率和能量利用率，降低排烟热损失，整体能耗得到明显降低；铝灰中所含金属铝在高温下遇明火后会发生剧烈燃烧，既作为原料，又作为燃料，燃烧过程中放出大量的热，能够进一步提高能量利用率，同时降低燃料成本。
 附图说明
图1是实施例一中所述窑炉的结构示意图之一；
图2是实施例一中所述窑炉的结构示意图之二；
图3是实施例三中所述窑炉的结构示意图之一；
图4是图3中燃烧器与物料喷进管的俯视图；
图5是实施例三中所述窑炉的结构示意图之二。
图中：1、炉体；2、炉腔；3、喷火吹氧口；4、燃烧器；5、反应区；6、成品氧化铝出口；7、出料装置；8、出料导移板；9、吹氧管；10、弯头；11、进料口；12、排气通道；13、物料喷进管；14、预燃室；15、沉降腔室；16、废气口；17、产品出料口；18、全氧燃烧器。
 具体实施方式
下面结合附图对本发明的实施例做进一步描述：
实施例一
本实施例中的原料采用1吨电解铝生产过程中产生的一次铝灰，该原料的主要成分为12.8%的金属铝、19.2%的氮化铝、49.2%的氧化铝、18.8%的含氟盐类及其他金属氧化物。
利用铝灰制备氧化铝的工艺过程如下：
先将一次铝灰进行预处理，即破碎、球磨、筛分，之后造粒，得到粒径均匀的铝灰颗粒。
利用铝灰颗粒制备氧化铝时，先将窑炉内温度升至1400℃-1600℃，之后将铝灰颗粒加入窑炉中，使其在高温下进行全氧燃烧，在全氧燃烧过程中通入过量氧气，经过4小时后得到成品氧化铝（本实施例中制备的氧化铝为高温氧化铝和活性氧化铝，根据产品的需要控制出料速度来控制产品在窑炉内停留时间）。全氧燃烧过程中产生的氟气、二氧化硫、一氧化氮、二氧化氮等废气从窑炉炉腔排出后，依次通入SNCR脱硝设备（高温非催化还原法脱硝）、烟气冷却器、风除尘器、SDS干法脱硫脱氟塔、低压脉冲布袋除尘器、SCR脱硝设备（选择性催化还原法脱硝）、引风机、湿式脱氟塔中进行环保处理，达标后烟囱排放。
本实施例中使用的窑炉如图1、2所示，炉体1为立式结构，炉体1上部具有进料结构，炉壁上设有若干喷火吹氧口3，喷火吹氧口3处安装燃烧器4，燃料与氧气在燃烧器4内混合燃烧，炉体1下部具有出料口，出料口处安装出料速度可控的出料装置7，炉体1上部设有排气通道12。
本实施例中：
出料装置7采用常规煤气发生炉排渣工艺中使用的旋转出料托盘，旋转出料托盘上固定有向下导移的塔山结构，塔山上具有出料导移板8，成品氧化铝出口6设在旋转出料托盘的圆周上，当旋转出料托盘旋转时带动塔山跟着转动，塔山上的出料导移板产生向下压力，把粉状氧化铝从炉体下方压出。
进料结构为设置在炉体1顶部的进料口11。铝灰颗粒直接通过上方的进料口11加入炉腔2内，与燃烧火焰接触并进行全氧燃烧。
喷火吹氧口3设置一排，其作用是为铝灰全氧燃烧提供燃烧火焰（燃烧器4中的燃料与氧气混合燃烧），也可以仅为铝灰全氧燃烧补充足够氧气（燃烧器4中的燃料管路关闭，仅通过氧气管路向炉腔2内供应氧气）。
炉体1底部设有向上通氧的吹氧管9，吹氧管9顶部具有弯头10且管口朝下。通过吹氧管9自下而上向炉腔2内补充氧气，使铝灰中的金属铝充分反应，提高氧化铝的产量，吹氧管9顶部弯头10的设计能够有效防止下行的粉末堵塞吹氧管9管口。
使用时，开启燃烧器4，使燃料与氧气在燃烧器4内反应并向炉腔2内喷出燃烧火焰，当炉腔2内温度达到1500℃时，将铝灰颗粒通过进料口11通入窑炉的炉腔2内，铝灰在高温火焰下全氧燃烧。窑炉设计为立式结构，铝灰在全氧燃烧的同时会靠其自重自动下行，调整旋转出料托盘的出料速度，在其缓慢出料作用下铝灰缓慢下行，在该过程中，铝灰中的金属铝等物质能够进行充分反应，反应得到的氧化铝缓慢下行至下方出料口处，在下行及出料过程中逐渐冷却，最终将得到的成品氧化铝输送至仓库。
经检测，所得氧化铝中：氧化铝含量为97.85%，氧化镁含量为0.21%，氧化硅含量为0.48%，氧化钠含量为0.56%，氧化钙含量为0.18%，氧化铁含量为0.21%，以及其他氧化物，无含氟物质。
通过本实施例制得的成品氧化铝为中高品位氧化铝，可用作高档中高铝球、高铝球以及中高档耐火材料、功能陶瓷的制备等，使一次铝灰得到了更加充分的利用。另外，本实施例中所使用的原料，原料商需给予处理厂家800元-1000元/吨的处理费，整体工艺成本费在700元/吨，而通过本实施例制得的成品氧化铝售价在2200元-2500元/吨，经济效益可观，适于工业化应用。
相比现有酸浸、碱浸等方法制备氧化铝的工艺，本实施例所述工艺步骤简单，生产成本低，只需将铝灰通入窑炉并进行高温全氧燃烧，即可将铝灰中所含金属铝充分氧化，最终得到成品氧化铝，工艺中产生的废气则通入环保设备进行处理。
相比传统空气燃烧，采用全氧燃烧能够提高加热效率，同时能够大幅减少烟气量，降低排烟热损失，整体能耗得到明显降低。另外，本实施例所用一次铝灰中含有大量金属铝，金属铝在窑炉内会发生剧烈燃烧，既作为原料，又作为燃料，也就是说，当窑炉内金属铝燃烧后，可以关闭燃料管路，停止燃烧器4中燃料的供应，以金属铝自身作为燃料，其燃烧过程中放出大量的热，提高了能量利用率，同时降低燃料成本。
实施例二
本实施例中的原料采用1吨回收再生铝厂产生的二次铝灰，该原料的主要成分为3.3%的金属铝、17.2%的氮化铝、50.3%的氧化铝、29.2%的含氟盐类及其他金属氧化物。将二次铝灰进行破碎、球磨、筛分，之后造粒，得到粒径均匀的铝灰颗粒。
本实施例中制备氧化铝工艺中所用的窑炉结构与实施例一中所述结构相同，制备氧化铝的工艺方法也与实施例一基本相同，不同之处在于全氧燃烧的部分工艺参数，以下做具体说明：
本实施例中窑炉炉腔2内温度控制在1300℃-1600℃，经3.5小时后得到成品氧化铝。
经检测，所得氧化铝中：氧化铝含量为77.00%，氧化镁含量为7.25%，氧化硅含量为7.69%，氧化钠含量为1.33%，氧化钙含量为1.86%，氧化铁含量为2.63%，以及其他氧化物，无含氟物质。
通过本实施例制得的成品氧化铝为中高品位氧化铝，可用作高档中铝球、替代铝矾土、功能陶瓷的制备等，使二次铝灰得到了更加充分的利用。另外，本实施例中所使用的原料，原料商需给予处理厂家1400元-1600元/吨的处理费，整体工艺成本费在800元/吨，而通过本实施例制得的成品氧化铝售价在700-900元/吨，而且市场上二次铝灰的处理量非常大，经济效益很可观。
实施例三
本实施例中的原料采用1吨回收再生铝厂产生的二次铝灰，该原料的主要成分为3.3%的金属铝、17.2%的氮化铝、50.3%的氧化铝、29.2%的含氟盐类及其他金属氧化物，即与实施例二采用的铝灰成分相同。
不同的是：二次铝灰进行破碎、球磨、筛分，得到铝灰粉末后，并未进行后续造粒，直接用铝灰粉末制备氧化铝；本实施例中的窑炉结构与实施例一中所述结构有所区别，本实施例中制备氧化铝工艺中所用的窑炉结构如图3-5所示：
炉体1为立式结构，炉体1上部具有进料结构，炉壁上设有若干喷火吹氧口3，喷火吹氧口3处安装燃烧器4，燃料与氧气在燃烧器4内混合燃烧，炉体1下部具有出料口，出料口处安装出料速度可控的出料装置7，炉体1上部设有排气通道12。
本实施例中：
进料结构包括接入喷火吹氧口3中的物料喷进管13和设置在炉体1顶部的进料口11。铝灰粉末可以全部通过物料喷进管13通入炉腔2中，也可以一部分通过物料喷进管13、另一部分通过进料口11送入炉腔2内，进行全氧燃烧。
喷火吹氧口3设有上下两排，两排喷火吹氧口3上下对齐，其中：位于上方的一排喷火吹氧口3接物料喷进管13，物料喷进管13的喷出口和燃烧器4的喷火口均位于喷火吹氧口3的前部进口位置，燃烧器4的喷火口与物料喷进管13的喷出口之间呈30°的夹角，使物料喷进管13喷出的铝灰粉末与燃烧火焰能够更好的混合，喷火吹氧口3的中后部（即靠近炉腔2的位置）形成预燃室14；位于下方的一排喷火吹氧口3未接物料喷进管13，只安装燃烧器4。
炉体1底部设有向上通氧的吹氧管9，吹氧管9顶部具有弯头10且管口朝下。
排气通道12后方连接四级沉降腔室15，通过沉降腔室15能够将炉腔2内随高温废气上行至排气通道12中的粉末进行沉降收集，每一级沉降腔室15的底部设有产品出料口17，将粉末中所含氧化铝进行回收，提高最终氧化铝的收率。本实施例中的沉降腔室15采用上下往返式设计，气体沿S型路径经过四级沉降腔室15（如图5所示），以提高沉降效果；最后一级腔室的上部开有废气口16。
另外，本实施例在排气通道12内以及沉降腔室15上部分别安装全氧燃烧器18，将随高温废气排至排气通道12中的未反应的金属铝充分反应，进一步提高氧化铝的收率。
使用本实施例所述窑炉利用铝灰制备氧化铝的工艺方法如下：
开启燃烧器4，使燃料与氧气在燃烧器4内反应并向炉腔2内喷出燃烧火焰，当窑炉炉腔内温度升至1500℃时，将铝灰粉末送入炉腔2内。本实施例中铝灰粉末全部通过物料喷进管13通入，铝灰粉末与燃烧火焰在预燃室14内接触混合并实现预燃，之后铝灰粉末随燃烧的火焰输送至窑炉炉腔2中进行全氧燃烧，将窑炉炉腔2内温度控制在1400℃-1600℃，燃烧过程中通入过量氧气，使铝灰中的金属铝等充分反应，经过3小时后得到成品氧化铝（本实施例中所得成品氧化铝为高温活性氧化铝），成品氧化铝在旋转出料托盘作用下从出料口排出并输送至仓库。另外，有一部分粉料会随高温气流上行，并随废气进入排气通道12，这部分粉料中可能包含制得的氧化铝、未反应的金属铝等，未反应的金属铝流经排气通道12以及第一级沉降腔室15的全氧燃烧器18时全氧燃烧生成氧化铝，并在所述四级沉降腔室15中实现上下往返式沉降，对剩余的氧化铝进行回收。整个全氧燃烧过程中所产生的氟气、二氧化硫、一氧化氮、二氧化氮等废气依次通入SNCR脱硝设备（高温非催化还原法脱硝）、烟气冷却器、风除尘器、SDS干法脱硫脱氟塔、低压脉冲布袋除尘器、SCR脱硝设备（选择性催化还原法脱硝）、引风机、湿式脱氟塔中进行环保处理，达标后烟囱排放。另外，全氧燃烧过程中，通过第二排喷火吹氧口3中的燃烧器4以及下部的吹氧管9向窑炉炉腔2的反应区5补入足够氧气，当通过燃烧器4为铝灰全氧燃烧补充氧气时，只需将燃烧器4中的燃料管路关闭，这样就能直接通过氧气管路向炉腔2内供应氧气。 
经检测，本实施例所制得的成品氧化铝中：氧化铝含量为78.2%，氧化镁含量为7.45%，氧化硅含量为7.44%，氧化钠含量为1.56%，氧化钙含量为1.82%，氧化铁含量为2.39%，以及其他氧化物，无含氟物质。
通过本实施例制得的成品氧化铝与实施例二相同，为中高品位氧化铝，可用作高档中铝球、替代铝矾土、功能陶瓷的制备等，经济效益很可观。
将本实施例与实施例二对比可知：相比铝灰颗粒，利用铝灰粉末制备氧化铝能够提高整体生产效率，使铝灰能够更加充分的反应；通过对废气进行后续沉降及二次全氧燃烧，能够使未反应的金属铝进行反应，进一步提高氧化铝的收率。
实施例四
本实施例中的原料采用1吨回收再生铝生产过程中产生的铝灰除尘灰，该原料的主要成分为1.7%的金属铝、45.6%的氧化铝、15.7%的氮化铝、37%的含氟盐类及其他金属氧化物。
本实施例中制备氧化铝工艺中所用的窑炉结构与实施例三中所述结构相同，制备氧化铝的工艺方法也与实施例三基本相同，不同之处仅在于全氧燃烧的部分工艺参数，本实施例中窑炉炉腔2内温度控制在1000℃-1200℃，经3小时后得到成品氧化铝。
本实施例所制得的成品氧化铝中：氧化铝含量为68.5%，氧化镁含量为8.5%，氧化硅含量为11.3%，氧化钠含量为2.9%，氧化钙含量为4.3%，氧化铁含量为3.2%，以及其他氧化物，无含氟物质。
通过本实施例制得的成品氧化铝为中品位氧化铝，可用作普通中铝球、替代铝矾土、功能陶瓷的制备等，使环保灰得到了更加充分的利用。另外，本实施例中所使用的原料，原料商需给予处理厂家2000元-2400元/吨的处理费，整体工艺成本费在900元/吨，而通过本实施例制得的成品氧化铝售价在400元-700元/吨，经济效益也较为可观。
实施例五
本实施例中的原料采用1吨金属铝制品加工制造产生的铝灰，该原料的主要成分为7.4%的金属铝、18.3%的氮化铝、48.7%的氧化铝、25.6%的含氟盐类及其他金属氧化物。
本实施例中制备氧化铝工艺中所用的窑炉结构与实施例三中所述结构相同，制备氧化铝的工艺方法也与实施例三基本相同，不同之处仅在于全氧燃烧的部分工艺参数，本实施例中窑炉炉腔2内温度控制在1400℃-1600℃，经4小时后得到成品氧化铝。
本实施例所制得的成品氧化铝中：氧化铝含量为85.9%，氧化镁含量为3.63%，氧化硅含量为5.87%，氧化钠含量为1.34%，氧化钙含量为0.99%，氧化铁含量为0.23%，以及其他氧化物，无含氟物质。
通过本实施例制得的成品氧化铝为中高品位氧化铝，可用作中高档中铝球、高铝球以及中高档耐火材料、功能陶瓷的制备等，使金属铝制品加工制造产生的铝灰得到了更加充分的利用。另外，本实施例中所使用的原料，原料商需给予处理厂家600元-1000元/吨的处理费，整体工艺成本费在700元/吨，而通过本实施例制得的成品氧化铝售价在1400元-2000元/吨，经济效益可观，适于工业化应用。
分析以上实施例一~实施例五可知，本发明所述制备氧化铝的工艺相比酸浸、碱浸等制备氧化铝的步骤更为简单，生产成本低、能耗低，且经济收益高，适于工业化应用。

Claims (16)

  1. 一种利用铝灰制备氧化铝的工艺，其特征在于：先将窑炉炉腔内温度升至800-1600℃，之后将铝灰通入窑炉，使其在高温下进行全氧燃烧，在全氧燃烧过程中通入过量氧气，得到成品氧化铝，全氧燃烧过程中产生的废气从窑炉炉腔排出后进行环保处理。
  2. 根据权利要求1所述的利用铝灰制备氧化铝的工艺，其特征在于：所述铝灰呈粉末状，铝灰粉末全部通过喷火吹氧口送入窑炉炉腔内，或者一部分通过喷火吹氧口、另一部分通过进料口送入窑炉炉腔内。
  3. 根据权利要求2所述的利用铝灰制备氧化铝的工艺，其特征在于：随喷火吹氧口通入窑炉的铝灰粉末，在通入窑炉炉腔之前先与喷火吹氧口中燃烧器喷出的燃烧火焰接触，实现预燃后，铝灰粉末随燃烧的火焰输送至窑炉炉腔中。
  4. 根据权利要求1-3中任一所述的利用铝灰制备氧化铝的工艺，其特征在于：窑炉炉腔排出的废气进行一级或多级沉降，回收废气中的氧化铝。
  5. 根据权利要求4所述的利用铝灰制备氧化铝的工艺，其特征在于：窑炉炉腔排出的废气进行一级沉降之前和/或经过一级沉降时，进行二次全氧燃烧，将废气中未反应的金属铝反应得到氧化铝，并进行回收。
  6. 根据权利要求1所述的利用铝灰制备氧化铝的工艺，其特征在于：所述铝灰呈颗粒状，铝灰颗粒直接通过进料口加入窑炉炉腔中。
  7. 根据权利要求1、2、3、5或6所述的利用铝灰制备氧化铝的工艺，其特征在于：全氧燃烧过程中，向窑炉炉腔的反应区中补入氧气。 
  8. 一种权利要求1-7中任一所述工艺中使用的窑炉，其特征在于：炉体（1）为立式结构，炉体（1）上部具有进料结构，炉壁上设有若干喷火吹氧口（3），喷火吹氧口（3）处安装燃烧器（4），燃料与氧气在燃烧器（4）内混合燃烧，炉体（1）下部具有出料口，出料口处安装出料速度可控的出料装置（7），炉体（1）上部设有排气通道（12）。
  9. 根据权利要求8所述的窑炉，其特征在于：所述进料结构为接入喷火吹氧口（3）中的物料喷进管（13）。
  10. 根据权利要求9所述的窑炉，其特征在于：物料喷进管（13）的喷出口和燃烧器（4）的喷火口均位于喷火吹氧口（3）的前部进口位置，喷火吹氧口（3）的中后部形成预燃室（14）。
  11. 根据权利要求9或10所述的窑炉，其特征在于：燃烧器（4）的喷火口与物料喷进管（13）的喷出口之间存在一定的夹角α。
  12. 根据权利要求8-10中任一所述的窑炉，其特征在于：喷火吹氧口（3）设置一排或多排；当设置多排时，相邻两排的上下喷火吹氧口（3）对齐或者交错设置。 
  13. 根据权利要求8-10中任一所述的窑炉，其特征在于：炉体（1）底部设有向上通氧的吹氧管（9），吹氧管（9）顶部具有弯头（10）且管口朝下。 
  14. 根据权利要求8-10中任一所述的窑炉，其特征在于：排气通道（12）后方连接一级或者多级沉降腔室（15），每一级沉降腔室（15）的底部设有产品出料口（17），在最后一级腔室的上部开有废气口（16）。
  15. 根据权利要求14所述的窑炉，其特征在于：排气通道（12）以及沉降腔室（15）上安装全氧燃烧器（18）。
  16. 根据权利要求8或9所述的窑炉，其特征在于：所述进料结构为设置在炉体（1）上的进料口（11）。
PCT/CN2023/124628 2023-10-14 2023-10-14 利用铝灰制备氧化铝的工艺及窑炉 Pending WO2025076848A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
KR1020247032847A KR20250054222A (ko) 2023-10-14 2023-10-14 알루미늄 재를 이용한 산화 알루미늄 제조공정 및 킬린
PCT/CN2023/124628 WO2025076848A1 (zh) 2023-10-14 2023-10-14 利用铝灰制备氧化铝的工艺及窑炉
TW113121168A TWI900050B (zh) 2023-10-14 2024-06-07 利用鋁灰製備氧化鋁的窯爐

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2023/124628 WO2025076848A1 (zh) 2023-10-14 2023-10-14 利用铝灰制备氧化铝的工艺及窑炉

Publications (1)

Publication Number Publication Date
WO2025076848A1 true WO2025076848A1 (zh) 2025-04-17

Family

ID=95396405

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/124628 Pending WO2025076848A1 (zh) 2023-10-14 2023-10-14 利用铝灰制备氧化铝的工艺及窑炉

Country Status (2)

Country Link
KR (1) KR20250054222A (zh)
WO (1) WO2025076848A1 (zh)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104692430A (zh) * 2015-03-20 2015-06-10 洛阳金石再生资源开发有限公司 一种用于刚玉生产的铝灰处理系统
CN206695591U (zh) * 2017-03-03 2017-12-01 洛阳金石再生资源开发有限公司 一种用于刚玉生产的铝灰烘干窑
CN111170750A (zh) * 2020-01-22 2020-05-19 北京矿冶科技集团有限公司 通过将二次铝灰无害化处理以制造耐火材料的方法
CN111573701A (zh) * 2020-05-20 2020-08-25 沈阳益富冶炼技术装备有限公司 一种利用铝灰制备棕刚玉生产原料的方法
CN113185266A (zh) * 2021-05-10 2021-07-30 陈强 一种利用废铝灰生产陶瓷砖原料的方法
CN113912097A (zh) * 2021-09-16 2022-01-11 佛山市吉力达铝材科技有限公司 一种铝灰渣的无害化处理方法
CN115650268A (zh) * 2022-11-04 2023-01-31 秦皇岛信宝资源循环科技有限公司 一种废铝灰火法处理工艺

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104692430A (zh) * 2015-03-20 2015-06-10 洛阳金石再生资源开发有限公司 一种用于刚玉生产的铝灰处理系统
CN206695591U (zh) * 2017-03-03 2017-12-01 洛阳金石再生资源开发有限公司 一种用于刚玉生产的铝灰烘干窑
CN111170750A (zh) * 2020-01-22 2020-05-19 北京矿冶科技集团有限公司 通过将二次铝灰无害化处理以制造耐火材料的方法
CN111573701A (zh) * 2020-05-20 2020-08-25 沈阳益富冶炼技术装备有限公司 一种利用铝灰制备棕刚玉生产原料的方法
CN113185266A (zh) * 2021-05-10 2021-07-30 陈强 一种利用废铝灰生产陶瓷砖原料的方法
CN113912097A (zh) * 2021-09-16 2022-01-11 佛山市吉力达铝材科技有限公司 一种铝灰渣的无害化处理方法
CN115650268A (zh) * 2022-11-04 2023-01-31 秦皇岛信宝资源循环科技有限公司 一种废铝灰火法处理工艺

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HOU RUIHONG, WANG HAO; CHEN JIN; ZHANG FENGLIN; SONG JIAWEI: "High Temperature Calcinations of Aluminum Dross for Alumina", CHEMICAL INDUSTRY AND ENGINEERING PROGRESS, BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY, MEMBER OF CHINESE ACADEMY OF ENGINEERING, PROFESSOR, CHINA, vol. 35, no. 8, 5 August 2016 (2016-08-05), pages 2523 - 2527, XP093304512, ISSN: 1000-6613, DOI: 10.16085/j.issn.1000-6613.2016.08.34 *

Also Published As

Publication number Publication date
TW202515821A (zh) 2025-04-16
KR20250054222A (ko) 2025-04-22

Similar Documents

Publication Publication Date Title
CN101269919B (zh) 一种煅烧物料的竖窑装置
CN103058536B (zh) 蓄热式间壁加热回转窑装置
CN206454491U (zh) 一种利用高炉渣固定二氧化碳并回收显热的装置
CN216431725U (zh) 水泥窑协同处置固危废的外挂式预热、预燃阶梯炉装置
CN109306407B (zh) 一种冶金含锌除尘灰治理及利用的装置和方法
CN102776309A (zh) 一种钢铁厂含锌粉尘的处理方法
CN101956037A (zh) 间接加热式还原炼铁的方法和装置
CN106823774A (zh) 一种利用高炉渣固定二氧化碳并回收显热的装置和方法
CZ302348B6 (cs) Zpusob a zarízení pro výrobu minerálních vláken
CN113088611B (zh) 一种纯氧两段式预热还原炼铁工艺
CN101172652A (zh) 矾矿钙法步进式焙烧方法及焙烧炉
CN102766760B (zh) 一种高价氧化锰矿的隧道窑还原焙烧方法
CN110205431B (zh) 回转窑煤基直接还原增氧熔分炉短流程铁水生产工艺
CN101749931A (zh) 冶炼熔炉
CN102012160A (zh) 冶炼熔炉
CN102121788A (zh) 冶炼熔炉
TWI900050B (zh) 利用鋁灰製備氧化鋁的窯爐
CN221825917U (zh) 制备氧化铝用窑炉
CN103352128A (zh) 直接锌煤混合旋风燃烧式氧化锌生产系统
CN115164202A (zh) 多相耦合有机/含重固废协同处置工艺、系统及控制方法
WO2025076848A1 (zh) 利用铝灰制备氧化铝的工艺及窑炉
CN110343878B (zh) 一种节能环保的镍铁合金生产方法
CN116083673B (zh) 一种高炉热风炉烟气串级利用同步脱硫脱硝系统
CN116042945B (zh) 高炉热风炉烟气余热深度利用耦合脱硫脱硝工艺
CN116697604B (zh) 一种具有煅烧煤矸石功能的热风炉装置及使用方法

Legal Events

Date Code Title Description
WWP Wipo information: published in national office

Ref document number: 1020247032847

Country of ref document: KR

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23955222

Country of ref document: EP

Kind code of ref document: A1