WO2024132555A2 - Procédé de régénération d'acide - Google Patents

Procédé de régénération d'acide Download PDF

Info

Publication number
WO2024132555A2
WO2024132555A2 PCT/EP2023/084682 EP2023084682W WO2024132555A2 WO 2024132555 A2 WO2024132555 A2 WO 2024132555A2 EP 2023084682 W EP2023084682 W EP 2023084682W WO 2024132555 A2 WO2024132555 A2 WO 2024132555A2
Authority
WO
WIPO (PCT)
Prior art keywords
metal
heat transfer
transfer medium
acid
containing solution
Prior art date
Application number
PCT/EP2023/084682
Other languages
German (de)
English (en)
Inventor
Martin BRAZDA
Andreas Rechberger
Frank Baerhold
Stefan MITTERECKER
Original Assignee
Andritz Ag
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 Andritz Ag filed Critical Andritz Ag
Publication of WO2024132555A2 publication Critical patent/WO2024132555A2/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/36—Regeneration of waste pickling liquors
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
    • C23G1/08—Iron or steel
    • C23G1/086—Iron or steel solutions containing HF

Definitions

  • the subject of this invention is a process for the extraction or recovery of acids from metal-containing solutions of the acid by pyrohydrolytic treatment of the solution and subsequent absorption and/or condensation of the gaseous acid formed in the process, wherein the metal-containing solution is fed to a heated reactor chamber in which the metal-containing solution is evaporated and in which a pyrolytic decomposition into acids and metal oxides takes place.
  • Solutions of metal salts such as hydrochloric or hydrofluoric acid
  • metal salts such as hydrochloric or hydrofluoric acid
  • pickling in the steel industry where scale is removed by means of a chemical reaction with hydrochloric acid or mixtures of nitric acid and hydrofluoric acid, or in the extraction of non-ferrous metals from ore liquors.
  • the acids used in these processes are regenerated and fed back into the process, creating a closed acid cycle. If the regeneration process is selected appropriately, metal oxides can be extracted as valuable materials from the metals contained in the solution.
  • ANDRITZ AG offers acid regeneration plants for the regeneration of pickling solutions from the treatment of carbon and stainless steels, as well as for the regeneration of solutions from leaching processes and the production of metal oxides from metal salt solutions.
  • These plants operate according to the pyrohydrolysis process, in which metal salt solutions (metal-containing solutions of the acid) are evaporated in spray roasting furnaces or fluidized bed reactors and the The metal salts remaining after evaporation are converted into metal oxides at high temperatures and in the presence of water vapor.
  • the amount of energy used is considerable and is provided exclusively by the combustion of mainly fossil fuels.
  • Spray roasting and fluidized bed systems have by far the largest market share of the acid regeneration processes used industrially and are offered by several companies, primarily for applications in the steel production sector.
  • the proven pyrohydrolysis process is often carried out in spray roasting ovens (spray roasting reactors).
  • AT 395 312 B describes a process in which the acid is recovered by spray roasting the metal-containing solution and subsequent absorption and/or condensation of the gases formed in an aqueous absorption solution.
  • the metal oxides formed during pyrohydrolysis are removed at the bottom of the spray roaster.
  • EP 0 775 760 A1 describes a similar process for the recovery of acid by pyrohydrolytic treatment, whereby the pickling residue is subjected to pre-evaporation prior to pyrohydrolysis.
  • DE 30 21 589 describes a process and a plant for producing hydrofluoric acid using an indirectly heated rotary kiln.
  • the energy required for the pyrohydrolysis is supplied using a gas burner.
  • US 3658483 A describes a process for recovering acid using a spray roasting reactor or a fluidized bed reactor.
  • the metal salt solution is atomized via nozzle lances attached to the top of a spray roasting furnace and brought into contact with hot gas so that the solution evaporates.
  • the remaining metal salt particles fall to the bottom and pass through a hotter zone where they reach the temperature required for thermal conversion and are converted to metal oxides in the presence of water vapor and possibly oxygen.
  • the metal oxide particles are drawn off at the bottom of the spray roasting furnace, while the hot gas as well as acid and water vapor leave the spray roasting furnace via the top and are fed to further process steps.
  • flue gas from the combustion of fossil fuels is used as hot gas, which is generated by burners firing directly into the furnace chamber.
  • This flue gas requires complex post-treatment to reduce emissions and represents a source of greenhouse gases.
  • the object of the invention is to provide an acid regeneration process with extensive avoidance of flue gases in the acid regeneration circuit.
  • the acid can be, for example, waste acids from pickling or leaching plants and similar applications.
  • a heat transfer medium is supplied to the reactor chamber for heating, by means of which the metal-containing solution is heated to the temperature required for pyrohydrolysis.
  • This heat transfer medium consists partly or completely of steam.
  • the pyrohydrolysis reactor is thus primarily heated by the supplied steam.
  • This heating is to be understood in such a way that the reactor chamber is not primarily heated by burners arranged in the reactor chamber, but primarily by the heat transfer medium, which is heated structurally separately from the reactor chamber before it is supplied to the reactor chamber. Heating by burners arranged in the reactor chamber is therefore no longer necessary.
  • the thermal energy required for the evaporation of the metal salt solution and pyrohydrolysis of the metal salts can be supplied to the heat transfer medium, for example, via a heat exchanger, by electrical heating or by partial electrical heating and additional combustion of fuels in the heat transfer medium.
  • the pyrohydrolysis of the metal-containing solution is carried out in a spray roasting reactor.
  • the pyrohydrolysis of the metal-containing solution is carried out in a fluidized bed reactor or in a rotary kiln, in which case the heating of the fluidized bed reactor or the rotary kiln is also carried out by the supply of hot steam as a heat transfer medium.
  • the heat transfer medium can, for example, be heated using a heat exchanger before it is fed into the reactor chamber.
  • the heat transfer medium is heated electrically, since the infrastructure for providing electrical energy for electrical heating is usually available.
  • a sufficiently high gas temperature water vapor temperature
  • Commercially available resistive process gas heaters are usually limited to outlet temperatures of 750 - 800 °C and cannot be designed for significantly higher temperatures using conventional heating conductor materials.
  • Plasma torches also available on the market can reach significantly higher temperatures, but are not economically viable for the application mentioned due to the low thermal output per unit and complex power electronics.
  • the required thermal output in the range of several MW is provided by directly heating the heat transfer medium in an arc plasma outside the pyrohydrolysis reactor.
  • the high energy densities in the arc plasma mean that high thermal outputs can be introduced into the heat transfer medium at high outlet temperatures using comparatively small apparatus.
  • the arc can be generated between electrodes fed with alternating voltage, similar to the Birkeland-Eyde reactor, which means that complex and costly power electronics can be dispensed with.
  • the heating of the heat transfer medium is not limited to electrical heating.
  • the required temperatures can be generated by heat exchange between combustion products and the heat transfer medium, without introducing combustion products into the heat transfer medium (hot gas). Emissions from combustion cannot be avoided in this way, but the cleaning of undiluted combustion gases is simpler and can be done using industrially proven and commercially available processes, whereas a mixture of process gases and combustion products is more complex due to the dilution of the combustion products alone.
  • the heat transfer medium is at least partially recirculated and reheated before it is fed into the reactor chamber.
  • the energy required for evaporation and hydrolysis in the pyrohydrolysis reactor is then introduced via a recirculated heat transfer medium, which essentially consists of steam.
  • the amount of recirculated heat transfer medium required for this is determined by the temperature to which the heat transfer medium can be heated.
  • the amount of recirculated heat transfer medium can be reduced, thereby reducing the hydraulic load on the pyrohydrolysis reactor and downstream plant components.
  • a reduction in the heat transfer medium temperature results in an increase in the process gas flow, which leads to larger and more expensive equipment in new plants.
  • Such an increase in the process gas flow is particularly disadvantageous when converting existing plants to electric heating, because the dimensioning of at least the main equipment is not easily possible.
  • the recirculated heat transfer medium is passed through an arc plasma.
  • the steam used for heating comes from another thermal process, for example highly superheated steam from gas turbines or blast furnaces, or saturated low-temperature steam from geothermal energy.
  • the heat transfer medium could also be heated electrically or with the help of a heat exchanger.
  • the steam could be heated with electric heaters to, for example, 650 °C and further heating could be carried out by burning a fuel gas. This further heating of the heat transfer medium could then be carried out with the help of heat exchangers or the fuel gas, such as hydrogen, could be burned directly in the heat transfer medium.
  • Combustion products can enter the heat transfer medium, but the amount is significantly reduced compared to conventional systems.
  • the metal-containing solution is subjected to evaporation before the pyrohydrolytic treatment.
  • the process works particularly well when hydrochloric acid solutions are used as the metal-containing solution and hydrochloric acid is recovered using the process. It is also conceivable that solutions of nitric acid and hydrofluoric acid, for example, are used as the metal-containing solution and that nitric acid and hydrofluoric acid are recovered using the process.
  • Fig. 1 shows an electrically heated variant with an open exhaust system
  • Fig. 2 shows a possibility to operate spray roasting plants with electrical heating completely exhaust-free
  • Fig. 3 shows an embodiment in which the heat transfer medium (water vapor) comes from another process
  • Fig. 4 shows a device for electrically heating the heat transfer medium by means of an arc plasma
  • FIGS 1 and 2 show examples of electrically heated variants without restricting the applicability to other heating methods mentioned.
  • the same reference symbols in the figures denote the same system parts or material flows.
  • Figure 1 shows an electrically heated variant with an open exhaust system.
  • pre-evaporator 3 evaporation
  • the heated heat transfer medium 11 from the electrical heating 7 is introduced into the spray roasting furnace 1, so that the sprayed metal salt solution 13 moves in countercurrent to the heat transfer medium 11.
  • the metal salt solution 13 is evaporated in the upper area of the spray roasting furnace 1 and the metal salts crystallize while the heat transfer medium 11 cools down.
  • the metal salt particles thus formed reach the lower area of the spray roasting furnace 1, where they are brought to a temperature by contact with the heat transfer medium 11 at which, in the presence of water vapor and possibly oxygen, a pyrohydrolysis of the metal salts to metal oxides 12 takes place.
  • Hydrochloric acid pickling solutions as are generally used for pickling carbon steels, contain, for example, iron chloride, which according to the reaction equation
  • the metal oxide particles 12 are discharged via the bottom of the spray roasting furnace 1, while the heat transfer medium 11 and acid vapor from the evaporation and pyrolysis of the metal salt solution 13 leave the furnace 1 via the furnace head (stream 18).
  • the gas is passed through a cyclone separator 2 and the separated particles 19 are returned to the spray roasting furnace 1.
  • the gas, essentially water vapor and acid vapor, is further washed in a Venturi scrubber 3, through which the metal salt solution 13 is circulated. This cools the gas, while part of the circulated metal salt solution 13 evaporates and is thus pre-concentrated.
  • the gas is brought into contact with water 16 via a mass transfer packing, so that hydrogen chloride contained in the gas is absorbed.
  • the hydrochloric acid thus produced is withdrawn as regenerated acid 14 for further use at the bottom of the column.
  • the exhaust fan 5 conveys the heat transfer medium 11 back to the spray roasting furnace 1, where it is overheated by the electrical heating 7 to a temperature suitable for the spray roasting of the respective metal salt.
  • a heat exchanger 22 can also be provided in all embodiments, by means of which the heat transfer medium 11 is heated.
  • the heat transfer medium 11 can also be heated by the combustion of hydrogen, where the combustion of hydrogen can also take place directly in the heat transfer medium 11.
  • a partial flow of the process gas 17 and thus a quantity of water vapor is discharged upstream of the electrical heater 7, which approximately corresponds to the quantity of water 16 that is fed into the absorption column 4.
  • a control valve 6 is provided for this purpose. While the system is filled with ambient air during start-up and the circulated gas consists primarily of air components, this proportion decreases due to the continuous discharge and is replaced by water vapor from the spray roasting. After a short operating time, the gas consists primarily of water vapor, which offers advantages in terms of the higher heat capacity compared to operation with, for example, heated ambient air. This water vapor then serves as a heat transfer medium 11 for the indirect heating of the reactor chamber 1.
  • the discharged gas 17 contains not only water vapor but also impurities and, as is usual in conventional spray roasting plants, must be removed in subsequent scrubber stages cleaned in order to comply with emission limits, e.g. for hydrogen chloride, chlorine and dust. If oxygen 15 is required for the pyrolysis reaction, it is added to the heat transfer medium 11 in pure form or as atmospheric oxygen before it is returned to the spray roasting oven 1.
  • the embodiment described is advantageous when sufficient process waste water from other processes is available that can be used as an absorbent in the absorption stage 4. This is the case, for example, in pickling processes, where water is usually generated from rinsing stages. If the use of additional water is to be avoided, the regenerated acid 14 can alternatively be generated from a condensation step. This is shown in Figure 2.
  • the acid vapor 18 is passed through a condenser 8, in which it is cooled below the dew point, so that a diluted regenerated acid 14 is generated in the separator 9.
  • the condenser 8 has a cooling water supply line 20 and a cooling water return line 21.
  • the heat transfer medium 11 is fed back to the electric heater 7 via the fan 10.
  • heating can be provided via heat exchanger 22 or via the direct combustion of hydrogen in the heat transfer medium 11.
  • the plant can be operated without exhaust gases and thus emissions with this completely closed process according to Figure 2.
  • an inert gas component in the system is not discharged, which leads to The result is that the required heat transfer medium flow 11 is significantly higher in order to take account of the lower specific heat capacity of the mixture of steam and inert gas. This requires a corresponding adjustment of the equipment dimensions and entails higher investment costs.
  • the inert gas content can be avoided by largely inerting the system by flushing it with steam before the actual acid operation, although this would lead to a significantly more complex process. In both cases, starting up and shutting down the system is associated with a considerable amount of highly diluted regenerate, which may have to be discarded.
  • Figure 3 shows yet another embodiment of the invention.
  • the hot heat transfer medium 11 i.e. water vapor
  • comes from other thermal processes for example highly superheated steam from gas turbines or blast furnaces, or saturated low-temperature steam from geothermal energy.
  • FIG. 4 shows the basic structure of an arc reactor 32 for heating the heat transfer medium 11.
  • the structure of the arc reactor 32 is similar to that of the Birkeland-Eyde reactor. In contrast to the Birkeland-Eyde reactor, however, it is not ambient air that is supplied here, but a heat transfer medium 11 that essentially consists of water vapor.
  • An arc is ignited between two water-cooled electrodes 23 and is deflected outwards in a semicircular shape by a static magnetic field between the poles 24.
  • the electrodes 23 are AC voltage is fed so that the arc is reignited at each zero crossing and the direction in which the arc is deflected changes. This creates the optical image of a plasma disk burning in the disk-shaped combustion chamber 25.
  • the heat transfer medium 11 is fed to the arc reactor 32 under slight excess pressure via a nozzle 26.
  • the heat transfer medium 11 is introduced into the combustion chamber 25 via a perforated refractory lining 27.
  • the heat transfer medium 1 cools the refractory lining 27, which is heated by thermal radiation from the plasma.
  • the heat transfer medium 11 flows radially in the direction of an external, circumferential collecting channel 28. This results in a mass and heat exchange between the plasma and the heat transfer medium 11, which leads to the heat transfer medium 11 being heated to 950 - 1200 °C.
  • the heat transfer medium 11 leaves the arc reactor 32 via the nozzle 29.
  • the magnetic field required to form the plasma disk is generated by electromagnets 30 which are attached directly to the poles 24.
  • the magnetic circuit is closed by the soft magnetic jacket 31 of the arc reactor 32.
  • Metal salt solution metal-containing solution of the acid

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

L'invention concerne un procédé d'obtention ou de récupération d'acide à partir de solutions métallifères (13) de l'acide par traitement pyrohydrolytique de la solution, puis absorption et/ou condensation de l'acide gazeux ainsi formé. La solution métallifère (13) est pour cela amenée à une chambre de réacteur (1) chauffée, dans laquelle la solution métallifère (13) s'évapore et dans laquelle se produit une décomposition pyrolytique en acides et en oxydes métalliques (12). Selon l'invention, un fluide caloporteur (11), en partie ou en totalité composé de vapeur d'eau, est amené à la chambre de réacteur (1) à des fins de chauffage, fluide au moyen duquel la solution métallifère (13) est chauffée à la température nécessaire à la pyrohydrolyse.
PCT/EP2023/084682 2022-12-20 2023-12-07 Procédé de régénération d'acide WO2024132555A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT509772022 2022-12-20
ATA50977/2022 2022-12-20

Publications (1)

Publication Number Publication Date
WO2024132555A2 true WO2024132555A2 (fr) 2024-06-27

Family

ID=89168066

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2023/084682 WO2024132555A2 (fr) 2022-12-20 2023-12-07 Procédé de régénération d'acide

Country Status (1)

Country Link
WO (1) WO2024132555A2 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3658483A (en) 1970-05-18 1972-04-25 Sued Chemie Ag Apparatus for the production of concentrated hydrohalogen acids and metal oxides
DE3021589A1 (de) 1979-06-15 1980-12-18 Ruthner Industrieanlagen Ag Verfahren und anlage zur gewinnung bzw. rueckgewinnung von flussaeure
AT395312B (de) 1987-06-16 1992-11-25 Andritz Ag Maschf Verfahren zur gewinnung bzw. rueckgewinnung von saeure aus metallhaltigen loesungen dieser saeure
EP0635586A1 (fr) 1993-07-21 1995-01-25 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Procédé de régénération d'acide chlorhydrique à partir d'installations de décapage
EP0775760A1 (fr) 1995-11-27 1997-05-28 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Procédé et appareil de production et/ou recupération d'acides à partir de solutions métallifères de ces acides

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3658483A (en) 1970-05-18 1972-04-25 Sued Chemie Ag Apparatus for the production of concentrated hydrohalogen acids and metal oxides
DE3021589A1 (de) 1979-06-15 1980-12-18 Ruthner Industrieanlagen Ag Verfahren und anlage zur gewinnung bzw. rueckgewinnung von flussaeure
AT395312B (de) 1987-06-16 1992-11-25 Andritz Ag Maschf Verfahren zur gewinnung bzw. rueckgewinnung von saeure aus metallhaltigen loesungen dieser saeure
EP0635586A1 (fr) 1993-07-21 1995-01-25 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Procédé de régénération d'acide chlorhydrique à partir d'installations de décapage
EP0775760A1 (fr) 1995-11-27 1997-05-28 Andritz-Patentverwaltungs-Gesellschaft m.b.H. Procédé et appareil de production et/ou recupération d'acides à partir de solutions métallifères de ces acides

Similar Documents

Publication Publication Date Title
DE60123707T2 (de) Lufttrennungsverfahren und -system zur Sauerstoffproduktion zur Verbrennungsunterstützung in einer Wärmeverbrauchsvorrichtung
DE60102707T2 (de) Verfahren und vorrichtung zur gewinnung von schwefel aus schwefelwasserstoff enthaltenden gasströmen
EP2346600A2 (fr) Installation à haut rendement en énergie pour la production de suie, de préférence en tant qu'ensemble énergétique avec des installations pour la production de dioxyde de silicium et/ou de silicium
US7597873B2 (en) Process and apparatus for the recovery of metal oxide particles
WO2015124474A1 (fr) Procédé et dispositif de séparation de gaz résiduaire lors de la combustion de certains métaux
DE3234311C2 (de) Verfahren zur Rückgewinnung von Metallen aus flüssiger Schlacke
DE3317497A1 (de) Verfahren zur herstellung von phosphorpentoxid und gegebenenfalls phosphorsaeure unter ausnutzung der reaktionswaerme
DE2159790B2 (de) Verfahren und Vorrichtung zur kontinuierlichen Herstellung von Schwefeldioxid hoher Reinheit
WO2024132555A2 (fr) Procédé de régénération d'acide
CN109737430A (zh) 一种危险废物处理系统及方法
EP2663661B1 (fr) Procédé de traitement d'un gaz de combustion contenant du dioxyde de carbone provenant d'un processus d'électrofusion
DE1467007A1 (de) Katalytisches Verfahren zur Gewinnung von Schwefelsaeure in mehreren Kontakt- und Absorptionsstufen
CN111410229A (zh) 一种高纯氧化钼的制备方法及装备
DE60125221T2 (de) Verfahren zur regenerierung verbrauchter halogensäure-laugelösungen
EP0244206B1 (fr) Récupération d'un mélange gazeux contenant du dioxyde de soufre à partir de résidus contenant des sulfates
EP0940166B1 (fr) Traitement de matière residuelle et des fumées
WO2015176943A1 (fr) Grillage de lithium à différentes valeurs de température, pression et excès de gaz en utilisant des tubes poreux comme brûleurs
EP0312742A2 (fr) Procédé de traitement thermique de déchets organiques ou contaminés par des produits organiques
WO2017129816A1 (fr) Procédé de réduction carbothermique d'oxyde de zinc en zinc
DE568126C (de) Abscheidung staubfoermiger Verunreinigungen bei der Verbrennung phosphorhaltiger Gase von Phosphorreduktionsoefen in feuerfesten Verbrennungskammern
DE102016012419A1 (de) Verfahren zur Wärmerückgewinnung aus einem von einem Brenner erzeugten Rauchgas und entsprechendes Wärmerückgewinnungssystem
DE756271C (de) Verfahren und Vorrichtung zum Gewinnen von metallischem Zink aus oxydischen Zinkverbindungen
AT406165B (de) Vorrichtung zur kontinuierlichen destillativen auftrennung von rohöl
DE660251C (de) Verdichter zum Gewinnen von Metallen aus Gasen oder Daempfen
EP0120109A1 (fr) Procédé et dispositif de commande de la combustion des gaz d'échappement d'un four à cubilot à air chaud