EP0759011A1 - Procede d'extraction ou de recuperation d'acides - Google Patents

Procede d'extraction ou de recuperation d'acides

Info

Publication number
EP0759011A1
EP0759011A1 EP96903826A EP96903826A EP0759011A1 EP 0759011 A1 EP0759011 A1 EP 0759011A1 EP 96903826 A EP96903826 A EP 96903826A EP 96903826 A EP96903826 A EP 96903826A EP 0759011 A1 EP0759011 A1 EP 0759011A1
Authority
EP
European Patent Office
Prior art keywords
metal
rust
nitric acid
evaporation
gases
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.)
Withdrawn
Application number
EP96903826A
Other languages
German (de)
English (en)
Inventor
Josef Dipl.-Ing. Dr. Jeney
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.)
Sad Edv-Systemanalyse und -Systemdesign GmbH
Original Assignee
Sad Edv-Systemanalyse und -Systemdesign GmbH
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 Sad Edv-Systemanalyse und -Systemdesign GmbH filed Critical Sad Edv-Systemanalyse und -Systemdesign GmbH
Publication of EP0759011A1 publication Critical patent/EP0759011A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B7/00—Halogens; Halogen acids
    • C01B7/19—Fluorine; Hydrogen fluoride
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/20—Nitrogen oxides; Oxyacids of nitrogen; Salts thereof
    • C01B21/38—Nitric acid
    • C01B21/46—Purification; Separation ; Stabilisation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
    • C01B13/14—Methods for preparing oxides or hydroxides in general
    • C01B13/34—Methods for preparing oxides or hydroxides in general by oxidation or hydrolysis of sprayed or atomised solutions
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B7/00—Halogens; Halogen acids
    • C01B7/19—Fluorine; Hydrogen fluoride
    • C01B7/191—Hydrogen fluoride
    • 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

Definitions

  • the invention relates to a process for the recovery or recovery of acids, in particular hydrofluoric acid and nitric acid, from metal-containing solutions.
  • Metal-containing solutions which contain hydrofluoric acid and nitric acid, fall in particular in the metal industry as nitric acid mixed acid pickling in the surface treatment of stainless steels.
  • Special alloys and special metals They contain free hydrofluoric acid, free nitric acid and iron dissolved as fluoride. Chrome and nickel.
  • nitric acid is particularly important at temperatures above 200 ° C
  • oxygen or other oxidizing agents such as hydrogen peroxide to NO 2 .
  • the recovery rates achievable according to this process are unsatisfactory. It is described that a maximum recovery rate of 33% of the nitric acid originally used is possible in one column. Only through additional oxidation measures. which naturally entails increased chemical expenditure and thus higher costs, a recovery rate of approx. 40% can be achieved in the second column.
  • the total amount of nitric acid recoverable from the metal-containing solution is a maximum of about 80% of the amount used when additional oxidation measures are used, the rest of the unreacted nitrogen oxides must be separated from the rust gases, e.g. in DeNOx systems, and is no longer available for the recovery of nitric acid
  • This task is solved according to the invention in that the metal-containing solution is evaporated at temperatures at which essentially no decomposition of the nitric acid takes place, that the metal-containing residue of the evaporation is treated pyrohydrolytically, the metal fluids being converted into metal oxides, and in that the resulting rust gases are separated from the rust gases
  • hydrofluoric acid and nitric acid can be separated from the metal-containing solutions by the sequence of process steps hydrofluoric acid and nitric acid with jerk rates of up to 90% and above, without having to resort to additional measures for oxidation or intensive cooling
  • the invention is based on the knowledge of removing a large part of the nitric acid in the metal-containing solution from the solution by evaporation below the decomposition temperature of the nitric acid.
  • the small amount of nitric acid remaining in the metal-containing residue is indeed partially decomposed in the reactor as described in the beginning, but this is The extent of the resulting nitric acid losses is so small that additional oxidation of the nitrogen oxides formed and conversion to nitric acid can be completely avoided
  • the evaporation of the metal-containing solution preferably takes place at temperatures below 200 ° C. and particularly advantageously in a temperature range from 80 to 120 ° C. it is ensured that no significant decomposition of the nitric acid takes place during evaporation
  • the evaporation is carried out at reduced pressure. This enables a gentler treatment of the metal-containing solution
  • the preliminary treatment of the metal-containing residue is preferably carried out in a spray rust reactor
  • the process according to the invention can be carried out even more efficiently if the temperature in the burner reactor is 500 to 700.degree. C., preferably 550 to 650.degree. C. At these higher temperatures, the pyrohvdrolysis reactions take place more quickly due to the fact that If only small amounts of nitric acid get into the spray rust reactor at all, the decomposition of the nitric acid, which also occurs more strongly at these higher temperatures, is of little importance
  • the rust gases are preferably passed through at least one absorption column to separate the acids present in the rust gases
  • the temperature in the absorption column is preferably kept above 70.degree. C., which means that essentially no cooling is carried out. This is not necessary because no measures are taken according to the invention to recover from the decomposition products which are likewise present in the rust gases in small quantities To gain nitric acid
  • part of the acidic solution emerging from the absorption column is circulated over the column
  • washing liquid accumulates more and more with absorbed acids and thus higher concentrations of hydrofluoric and nitric acids can be achieved
  • the metal-containing residue of evaporation with absorption liquid is dissolved or diluted from at least one of the absorption columns used
  • Particularly suitable as a liquid for dissolving or diluting the metal-containing residue is washing liquid from a second or third absorption column, in which no significant acid concentrations occur anymore. In this way, even slightly acidic wastewater can be recycled in a cycle
  • a metal-containing solution (1) is obtained.
  • the evaporator (002) is preferably a single-stage or multi-stage vacuum evaporator, in which the evaporation is carried out under reduced pressure, for example under pressure reduction to 0.5 bar, in one-stage systems.
  • the evaporation residue (3) can be dissolved or diluted in fresh water or preferably with the outlet (5) of an absorption column (012).
  • the main part of the evaporation residue contains metal fluorides as well as small amounts of metal nitrates and residues of non-evaporated nitric acid.
  • This diluted evaporation residue (6) is then conveyed into a reactor for pyrohvdrolviischen treatment, preferably a spray rust reactor (007).
  • the diluted evaporation residue (6) preferably passes through a flue gas scrubber (006) in which it comes into contact with roasting gases (8) from the spray roasting reactor (007) and is partially evaporated.
  • a part of the evaporation residue (6) can advantageously be circulated through the flue gas scrubber (006).
  • the resulting metal oxides (9) are continuously drawn off at the lower end ) in the flue gas scrubber (006). where they are also cooled by the diluted evaporation residue (6) from the container (005). At this point the decomposition reactions of the nitric acid are stopped due to the reversal of the equilibrium position of the reaction
  • the cleaned rust gases (15) pass from the flue gas scrubber (006) into a first absorption column Kl (01 1), the acids in the rust gases (15) being absorbed with water.
  • part ( 16) the mixed acid regenerated in this way is circulated over the absorption column Kl (01 1).
  • the rest (12) of the regenerated mixed acid from the column Kl (011) is pumped to the mixed acid storage tank (004)
  • the outflow from column K 1 (01 1) is cooled to just above 70 ° C. by means of cooling means (016)
  • the second absorption column K2 (012). which is also fed with water, serves primarily as an exhaust gas scrubber.A part of the washing liquid (5) created here can be used to dissolve or dilute the metal-containing evaporation residue. Part of the washing liquid can also be circulated in the column K2 (012)
  • the waste gases (13) still present after the second wash column (012) are in an alkaline scrubber W 1 (013). preferably freed from the last traces of acid using NaOH or other alkaline reagents and passed to a DeNOx plant (014) for the catalytic reduction of NOx with ammonia or urea
  • the exhaust gases (14) freed from acids and nitrogen oxides in this way are discharged into the atmosphere by an exhaust gas fan (015).
  • the exhaust gas fan (015) naturally also effects the entire gas transport through the plant, starting with the extraction of the roasting gases (10) from the reactor (007) up to the pushing out of the cleaned exhaust gases (14) through the chimney (014).
  • the sum of Fe is the sum of the metals Fe. Ni and Cr understood, the majority of Fe being formed.
  • This pickling agent (1) was evaporated in batches in a vacuum evaporator at a pressure between 200 and 500 mbar and at temperatures between 80 and 90 ° C. This gave a metal-containing concentrate (3) with the following composition:
  • the evaporation residue, i.e. H. the metal-containing concentrate (3). was rinsed from the evaporator (002) with water into the stirred tank (005) and dissolved there with further addition of water while stirring, resulting in 380 1 low-acid, metal-containing solution (6) with the following composition:
  • This reactor was heated with 7 m ' h of natural gas and 85 m7 h of air, a temperature of about 550 ° C. being established in the burner level.
  • the partial stream (1 1) of the pickling agent (6) was fed into the reactor head in an amount of 75 1 Ti injected
  • roasting gases (10) were sucked out of the reactor (007) by the negative pressure of the fan (15) and passed through the rust gas line (008) first into the dust separator (009) and then into the flue gas scrubber (006).
  • This enriched rust gas reaches the first absorption column (01 1), where the absorption of the HNO 3 . HF and part of the NO: component in the NO according to the equation 3 NO ⁇ - H - »2 HNO * NO

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Heat Treatment Of Water, Waste Water Or Sewage (AREA)
  • Treating Waste Gases (AREA)

Abstract

L'invention concerne un procédé d'extraction ou de récupération d'acides, en particulier d'acide fluoridique et d'acide nitrique à partir de solutions (1) contenant des métaux. Le procédé présenté se caractérise en ce que: la solution contenant des métaux est concentrée par évaporation (002) à des températures auxquelles il n'y a pratiquement pas de décomposition de l'acide nitrique; le résidu ne contenant pas de métaux résultant de cette évaporation est traité par pyrohydrolyse (007), ce qui produit la transformation des fluorures métalliques en oxydes métalliques (9); et les acides présents dans les gaz de calcination (10) sont séparés de ceux-ci. Selon le procédé présenté, l'acide fluoridique et l'acide nitrique peuvent être récupérés avec un haut rendement et à peu de frais.
EP96903826A 1995-03-07 1996-03-06 Procede d'extraction ou de recuperation d'acides Withdrawn EP0759011A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AT0039595A AT412001B (de) 1995-03-07 1995-03-07 Verfahren zur gewinnung bzw. rückgewinnung von säuren
AT395/95 1995-03-07
PCT/AT1996/000042 WO1996027554A1 (fr) 1995-03-07 1996-03-06 Procede d'extraction ou de recuperation d'acides

Publications (1)

Publication Number Publication Date
EP0759011A1 true EP0759011A1 (fr) 1997-02-26

Family

ID=3489470

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96903826A Withdrawn EP0759011A1 (fr) 1995-03-07 1996-03-06 Procede d'extraction ou de recuperation d'acides

Country Status (4)

Country Link
EP (1) EP0759011A1 (fr)
KR (1) KR970702819A (fr)
AT (1) AT412001B (fr)
WO (1) WO1996027554A1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0843025A1 (fr) * 1996-11-15 1998-05-20 Keramchemie GmbH Procédé de régénération de solutions de décapage usées
AT406168B (de) * 1998-09-03 2000-03-27 Eurox Eisenoxydproduktions Und Verfahren zur gewinnung bzw. rückgewinnung von flusssäure und salpetersäure
AT407757B (de) * 1999-03-22 2001-06-25 Andritz Patentverwaltung Verfahren zur rückgewinnung von säuren aus metallhaltigen lösungen dieser säuren
US6692719B1 (en) 2000-11-08 2004-02-17 Hatch Ltd. Process for regeneration of acid halide solutions
AT411900B (de) * 2001-04-25 2004-07-26 Andritz Ag Maschf Verfahren und vorrichtung zur gewinnung von metalloxiden
AT413697B (de) * 2001-11-07 2006-05-15 Andritz Ag Maschf Verfahren zur behandlung säurehältiger abwässer
DE10231308C5 (de) 2002-07-10 2009-10-15 Cmi Uvk Gmbh Verfahren und Vorrichtung zum Recyceln von Edelstahl-Beizbädern
ITBS20040093A1 (it) * 2004-09-03 2004-12-03 Ct Studi E Ricerche S R L Metodo di trattamento di un bagno di decapaggio esausto.
AT508774B1 (de) * 2010-04-20 2011-04-15 Key Technologies Ind Gmbh Verfahren zur gewinnung bzw. rückgewinnung von salpetersäure und flusssäure aus lösungen von edelstahlbeizanlagen
AT515104B1 (de) * 2014-03-04 2015-06-15 Michael Leonhartsberger Vorrichtung zur Aufbereitung von metallionenhältigen Lösungen
CN107601605B (zh) * 2017-10-20 2023-05-09 鞍山创鑫环保科技股份有限公司 一种提高不锈钢酸洗废液再生硝酸收率的工艺及系统
AT522594B1 (de) * 2019-09-03 2020-12-15 Umwandlung von Metallsaizösungen in flüssige Säuren und feste Metalloxide
AT522593B1 (de) * 2019-09-24 2020-12-15 Sustec Gmbh Rückgewinnung von Säuren und Metallen aus trockenen Salzverbindungen

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1311757A (en) * 1970-05-19 1973-03-28 Sued Chemie Ag Hydrogen halide production
AT335251B (de) * 1975-03-10 1977-03-10 Ruthner Industrieanlagen Ag Verfahren und vorrichtung zur wiedergewinnung von salpetersaure und flusssaure aus losungen
US4252602A (en) * 1978-10-04 1981-02-24 Ruthner Industrieanlagen-Aktiengesellschaft Apparatus for recovering nitric acid and hydrofluoric acid from solutions
AT376632B (de) * 1979-06-15 1984-12-10 Ruthner Industrieanlagen Ag Verfahren und anlage zur gewinnung bzw. rueckgewinnung von flussaeure
AT374508B (de) * 1982-07-01 1984-05-10 Ruthner Industrieanlagen Ag Verfahren zur aufarbeitung verbrauchter beizoder aetzloesungen auf der basis von salpeter-flussaeure
FI67409C (fi) * 1983-01-25 1985-03-11 Outokumpu Oy Foerfarande foer regenerering av betningssyror
AT395312B (de) * 1987-06-16 1992-11-25 Andritz Ag Maschf Verfahren zur gewinnung bzw. rueckgewinnung von saeure aus metallhaltigen loesungen dieser saeure
DE69220925T2 (de) * 1991-11-22 1997-12-11 Tech Resources Pty Ltd Regenerierung von Salzsäure
DE4315551C2 (de) * 1993-05-10 2003-01-16 Gewerk Keramchemie Verfahren zur Regenerierung von verbrauchten, Metallsalze und/oder Metalloxide enthaltenden Lösungen, insbesondere Milchsäuren

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9627554A1 *

Also Published As

Publication number Publication date
KR970702819A (ko) 1997-06-10
WO1996027554A1 (fr) 1996-09-12
AT412001B (de) 2004-08-26
ATA39595A (de) 1997-03-15

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