Method of purifying waste hydrochloric acid

Patent metadata

Field	Value
Publication number	US-11472702-B2
Application number	US-201715774915-A
Country	US
Kind code	B2
Filing date	Oct 25, 2017
Priority date	Nov 9, 2016
Publication date	Oct 18, 2022
Grant date	Oct 18, 2022

Abstract

The present invention relates to a method of purifying waste hydrochloric acid, and more particularly, to a method of purifying waste hydrochloric acid which includes preparing an extraction solution by dissolving an extractant in an organic solvent (S1), extracting metallic components with the organic solvent by adding the extraction solution to the waste hydrochloric acid (S2), separating a waste hydrochloric acid layer and the organic solvent containing the metallic components (S3), and obtaining purified hydrochloric acid by recovering the separated (fractionated) waste hydrochloric acid layer (S4), wherein the extractant is used in an amount of 40 moles or more based on 1 mole of iron (Fe) included in the waste hydrochloric acid, and the waste hydrochloric acid and the extraction solution are mixed in a volume ratio of 1:0.1 to 1:1.

First claim

The invention claimed is:

1. A method of purifying waste hydrochloric acid, the method comprising steps of:
preparing an extraction solution by dissolving an extractant in an organic solvent (S 1 );
extracting metallic components in waste hydrochloric acid with the extraction solution by adding the extraction solution to the waste hydrochloric acid, wherein the extracting is performed for 20 seconds to 60 seconds at atmospheric temperature while stirring a mixed solution of the waste hydrochloric acid and the extraction solution at a speed of 200 rpm to 600 rpm (S 2 );
separating a waste hydrochloric acid layer and the extraction solution containing the metallic components (S 3 ); and
obtaining purified hydrochloric acid by recovering the separated (fractionated) waste hydrochloric acid layer (S 4 ),
wherein the organic solvent comprises 1) at least one solvent selected from the group consisting of an aromatic hydrocarbon solvent, and an aliphatic hydrocarbon solvent, and 2) an alcohol,
wherein an amount of the extractant used is 50 to 60 moles based on 1 mole of an iron (Fe) ion component of the metallic components contained in the waste hydrochloric acid, and
wherein the waste hydrochloric acid and the extraction solution are mixed in a volume ratio of 1:0.1 to 1:1.

2. The method of claim 1 , further comprising a step of measuring a concentration of the iron (Fe) ion component of the metallic components contained in the waste hydrochloric acid (S 0 ), before the preparing of the extraction solution.

3. The method of claim 1 , wherein the aromatic hydrocarbon solvent comprises at least one selected from the group consisting of toluene and xylene,
the aliphatic hydrocarbon solvent comprises at least one alicyclic hydrocarbon solvent selected from the group consisting of methyl cyclohexane and cyclohexane, or a linear hydrocarbon solvent having 6 to 20 carbon atoms, and
the alcohol comprises a monovalent alcohol having 6 to 20 carbon atoms.

4. The method of claim 1 , wherein the extractant comprises at least one compound selected from the group consisting of trioctylamine, methyl isobutyl ketone, trialkylphosphine oxide, and tributyl phosphate.

5. The method of claim 4 , wherein the extractant comprises at least one compound selected from the group consisting of trioctylamine and methyl isobutyl ketone.

6. The method of claim 5 , wherein the extractant is trioctylamine.

7. The method of claim 1 , wherein the separating (S 3 ) is performed within 20 seconds.

8. The method of claim 1 , after the obtaining of the purified hydrochloric acid (S 4 ), further comprising steps of:
removing residual metallic components in the extraction solution by adding distilled water to the separated extraction solution containing the metallic components (S 5 );
separating a water layer and the extraction solution having the metallic components removed therefrom (S 6 ); and
recovering the separated extraction solution and water layer, respectively (S 7 ).

9. The method of claim 8 , wherein the extraction solution and the distilled water are mixed in a volume ratio of 1:1.

10. The method of claim 8 , wherein the removing (S 5 ) is performed for 20 seconds to 60 seconds at atmospheric temperature while stirring a mixed solution of the separated extraction solution and the distilled water at a speed of 200 rpm to 600 rpm.

11. The method of claim 8 , wherein the separating (S 6 ) is performed within 20 seconds.

12. A method of purifying waste hydrochloric acid, the method comprising steps of:
preparing an extraction solution by dissolving an extractant in an organic solvent (S 1 );
extracting metallic components in waste hydrochloric acid with the extraction solution by adding the extraction solution to the waste hydrochloric acid (S 2 );
separating a waste hydrochloric acid layer and the extraction solution containing the metallic components (S 3 ); and
obtaining purified hydrochloric acid by recovering the separated (fractionated) waste hydrochloric acid layer (S 4 ),
wherein an amount of the extractant used is 40 to 60 moles based on 1 mole of an iron (Fe) ion component of the metallic components contained in the waste hydrochloric acid, and
wherein the waste hydrochloric acid and the extraction solution are mixed in a volume ratio of 1:0.1 to 1:1, and
wherein the extractant comprises at least one compound selected from the group consisting of methyl isobutyl ketone, trialkylphosphine oxide, and tributyl phosphate, and
wherein the organic solvent comprises 1) at least one solvent selected from the group consisting of an aromatic hydrocarbon solvent, and an aliphatic hydrocarbon solvent, and 2) an alcohol.

Assignees

• Lg Chemical Ltd

Inventors

• Eom Hee Jun
• Lee Dong Chul
• Kim Yeon Yi
• Choi Jung Ho

Classifications

• C01G49/0009

  Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange · CPC title

• B01D2257/60

  Heavy metals or heavy metal compounds · CPC title

• B01D11/0292 Primary

  Treatment of the solvent · CPC title

• B01D11/0492 Primary

  Applications, solvents used · CPC title

• C01P2006/80

  Compositional purity · CPC title