Method for recovering vanadium and tungsten from leach solution of waste denitrification catalyst

Patent metadata

Field	Value
Publication number	US-10415117-B2
Application number	US-201515125114-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Mar 11, 2014
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

The present invention relates to a method for recovering vanadium and tungsten from a leach solution of a waste denitrification catalyst, and more specifically, to a method for recovering vanadium and tungsten from a leach solution of a waste denitrification catalyst comprising the steps of: recovering vanadium by adding acid and then adding a calcium compound to a leach solution of a waste denitrification catalyst to precipitate the vanadium; and recovering tungsten by adding acid and then adding a calcium compound to the remaining leach solution after recovering the vanadium to precipitate the tungsten.

First claim

The invention claimed is:

1. A method for recovering vanadium and tungsten from a leach solution of a waste denitrification catalyst, the method comprising the steps of:
recovering vanadium by adding acid and then adding a calcium compound to a leach solution of a waste denitrification catalyst to precipitate the vanadium; and
recovering tungsten by adding acid and then adding a calcium compound to the remaining leach solution after recovering the vanadium to precipitate the tungsten,
wherein pH is adjusted to greater than or equal to 10 and less than 12 by adding the acid to the remaining leach solution after recovering the vanadium.

2. The method of claim 1 , wherein the acid is at least one selected from a group consisting of hydrochloric acid, nitric acid, and sulfuric acid.

3. The method of claim 1 , wherein pH is adjusted to 12 to 13 by adding the acid to the leach solution of the waste denitrification catalyst.

4. The method of claim 1 , wherein the calcium compound is at least one selected from a group consisting of CaCl 2 and Ca(OH) 2 .

5. The method of claim 1 , wherein the calcium compound is added with an equivalent of 9 to 11 times larger than an equivalent of vanadium when precipitating the vanadium.

6. The method of claim 1 , wherein the calcium compound is added with an equivalent of 2 to 3 times larger than an equivalent of tungsten when precipitating the tungsten.

7. The method of claim 1 , wherein the vanadium and the tungsten are precipitated as Ca(VO 3 ) 2 and CaWO 4 , respectively.

8. The method of claim 1 , further comprising:
adding the tungsten to a hydrochloric acid solution after recovering.

9. A method for recovering vanadium and tungsten contained in a waste denitrification catalyst, the method comprising the steps of:
forming a mixture by mixing a sodium salt solution with the waste denitrification catalyst;
preparing a leach solution by providing, heating, and stirring the mixture in a sealed pressurized reactor and leaching vanadium and tungsten contained in the mixture;
recovering the vanadium by adding acid to the leach solution to lower the leach solution's pH and then adding a calcium compound to precipitate the vanadium; and
recovering tungsten by adding acid to the remaining leach solution after recovering the vanadium to lower the pH and then adding the calcium compound to precipitate the tungsten,
wherein pH is adjusted to greater than or equal to 10 and less than 12 by adding the acid to the remaining leach solution after recovering the vanadium.

10. The method of claim 9 , wherein the sodium salt is at least one selected from a group consisting of sodium hydroxide (NaOH), sodium carbonate (Na 2 CO 3 ), and sodium chlorate (NaClO 3 ).

11. The method of claim 9 , wherein the heating temperature is 225 to 250° C.

Assignees

• Korea Inst Geoscience & Mineral Resources

Inventors

• Lee Jin-Young
• Kumar Rajesh

Classifications

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title

• C22B3/12

  in inorganic alkaline solutions · CPC title

• C22B34/365 Primary

  from spent catalysts · CPC title

• C22B34/225

  from spent catalysts · CPC title

• C22B7/009

  General processes for recovering metals or metallic compounds from spent catalysts (for recovering specific metals C22B11/00 - C22B61/00) · CPC title