Method and device for regeneration of hydrochloric acid

Patent metadata

Field	Value
Publication number	US-10494259-B2
Application number	US-201415024755-A
Country	US
Kind code	B2
Filing date	Sep 15, 2014
Priority date	Sep 26, 2013
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The subject matter of the present invention is a method to extract or recover hydrochloric acid from hydrochloric acid solutions containing metal by means of pyrohydrolytic treatment, followed by absorption and/or condensation of the gaseous hydrogen chloride thus formed in order to form hydrochloric acid. According to the invention, a first partial flow of the hydrochloric acid solution containing metal undergoes pyrohydrolytic treatment and a second partial flow of the metal-containing solution is fed to the absorption column. A device for implementing the process according to the invention is also the subject of the present invention.

First claim

The invention claimed is:

1. Method to extract or recover hydrochloric acid from hydrochloric acid solutions containing metal by means of spray roasting followed by one or both of absorption and condensation of gaseous hydrogen chloride thus formed in order to form hydrochloric acid, comprising
providing an initial flow of hydrochloric acid solution containing metal;
splitting the flow of the hydrochloric acid solution containing metal into a first partial flow and a second partial flow of hydrochloric acid solution containing metal;
feeding the first partial flow of hydrochloric acid solution containing metal to a spray roaster to undergo pyrohydrolytic treatment, which releases gases;
directly contacting the gases released from the pyrohydrolytic treatment with the hydrochloric acid solution containing metal, thereby cooling the gases released from the pyrohydrolytic treatment and concentrating the hydrochloric acid solution containing metal;
feeding the second partial flow of hydrochloric acid solution containing metal directly to an absorption column without undergoing pyrohydrolytic treatment, thereby increasing a concentration of metal in the hydrochloric acid solution containing metal, wherein
at least one of the initial flow or the first partial flow of hydrochloric acid solution containing metal is concentrated by evaporation such that the first partial flow of hydrochloric acid solution containing metal fed to the spray roaster for pyrohydrolytic treatment is a concentrated solution.

2. Method according to claim 1 , wherein the step of cooling gases released from the pyrohydrolytic treatment via direct contact with the hydrochloric acid solution containing metal causes a concentration of hydrochloric acid solution containing metal to increase via evaporation prior to splitting the hydrochloric acid solution containing metal such that the first partial flow to the spray roaster and second partial flow to the absorption column are both a concentrated solution.

3. Method according to claim 2 , comprising mixing the second partial flow of hydrochloric acid solution containing metal with rinsing water before being fed to the absorption column.

4. Method according to claim 1 , comprising extracting hydrochloric acid from a ferrous solution and using the extracted hydrochloric acid in the hydrochloric acid solution containing metal.

5. Method according to claim 4 , comprising extracting a regenerated hydrochloric acid with an iron content of more than 10 g/l after the second partial flow of hydrochloric acid solution containing metal passes through the absorption column.

6. Method according to claim 1 , wherein the hydrochloric acid solution containing metal originates from a pickling process, comprising regenerating hydrochloric acid by extraction after the second flow of hydrochloric acid solution containing metal passes through the absorption column and recycling the regenerated hydrochloric acid containing metal to the pickling process.

7. Method according to claim 1 , wherein the hydrochloric acid solution containing metal originates from a leaching process, comprising regenerating hydrochloric acid by extraction after the second flow of hydrochloric acid solution containing metal passes through the absorption column and recycling the regenerated hydrochloric acid containing metal to the leaching process.

8. Method according to claim 1 , wherein the first partial flow of the hydrochloric acid solution containing metal is concentrated by evaporation prior to feeding to the spray roaster.

9. Method according to claim 1 , wherein both the first partial flow of the hydrochloric acid solution containing metal and the second partial flow of hydrochloric acid solution containing metal are a concentrated solution.

10. Method according to claim 9 , wherein the initial flow of hydrochloric acid solution containing metal is concentrated by evaporation prior to splitting into the first partial flow and second partial flow.

Assignees

• Andritz Ag Maschf

Inventors

• Barhold Frank

Classifications

• C23G1/36 Primary

  Regeneration of waste pickling liquors · CPC title

• B01J10/00

  Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor (B01J19/08 takes precedence; separation, e.g. distillation, also combined with chemical reactions B01D, {e.g. B01D3/009}) · CPC title

• C01G49/06

  Ferric oxide [Fe2O3] · CPC title

• C23F1/46

  Regeneration of etching compositions · CPC title

• C23G1/02

  with acid solutions · CPC title