Method for leaching precious metals contained in waste denitrification catalyst using pressure leaching process

Patent metadata

Field	Value
Publication number	US-10913989-B2
Application number	US-201515123624-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Mar 5, 2014
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

The present invention relates to a method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, and more specifically, to a method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, the method comprising the steps of: forming a mixture by mixing a waste denitrification catalyst with a sodium salt solution; and leaching vanadium and tungsten contained in the mixture by feeding the mixture into a sealed pressurized reactor, and then heating and stirring the mixture.

First claim

The invention claimed is:

1. A method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, the method comprising the steps of:
forming a mixture by mixing a waste denitrification catalyst with a sodium salt solution; and
leaching 90% or more of vanadium and tungsten contained in the mixture by feeding the mixture into a sealed pressurized reactor, and then heating and stirring the mixture,
wherein the waste denitrification catalyst includes vanadium (V) and tungsten (W) in oxide forms,
wherein the concentration of the sodium salt solution is 2.5 to 3 M,
wherein the heating temperature is 225° C. to 250° C., and
wherein the waste denitrification catalyst and the sodium salt solution are mixed to have a solid-liquid ratio (a weight (g) of the waste denitrification catalyst/a volume (mL) of the sodium salt solution) of 0.3 to 0.4,
wherein the sodium salt solution comprises at least one selected from the group consisting of sodium carbonate (Na 2 CO 3 ) and sodium chlorate (NaClO 3 ), wherein the pressure of the pressurized reactor is 20 to 80 atm, and wherein the stirring is performed at 700 to 1200 rpm.

2. The method of claim 1 , wherein the vanadium and the tungsten are leached in forms of NaVO 3 and Na 2 WO 4 , respectively.

3. A method for leaching precious metals contained in a waste denitrification catalyst by using a pressure leaching process, the method comprising the steps of:
coarsely grinding and then finely grinding a waste denitrification catalyst;
forming a mixture by mixing the coarsely and finely ground waste denitrification catalyst with a sodium salt solution; and
leaching 90% or more of vanadium and tungsten contained in the mixture by feeding the mixture in a sealed pressurized reactor, and then heating and stirring the mixture,
wherein the waste denitrification catalyst includes vanadium (V) and tungsten (W) in oxide forms,
wherein the concentration of the sodium salt solution is 2.5 to 3 M,
wherein the heating temperature is 225° C. to 250° C., and
wherein the waste denitrification catalyst and the sodium salt solution are mixed to have a solid-liquid ratio (a weight (g) of the waste denitrification catalyst/a volume (mL) of the sodium salt solution) of 0.3 to 0.4,
wherein the sodium salt solution comprises at least one selected from the group consisting of sodium carbonate (Na 2 CO 3 ) and sodium chlorate (NaClO 3 ),
wherein the pressure of the pressurized reactor is 20 to 80 atm, and wherein the stirring is performed at 700 to 1200 rpm.

4. The method of claim 3 , wherein the size of the coarsely and finely ground waste denitrification catalyst is 50 to 150 μm.

Assignees

• Korea Inst Geoscience & Mineral Resources

Inventors

• Lee Jin-Young
• Lee Hoo-In

Classifications

• Y02P10/20

  Recycling · CPC title

• C22B34/225

  from spent catalysts · CPC title

• C22B34/365 Primary

  from spent catalysts · CPC title

• C22B7/008

  by an alkaline or ammoniacal leaching · 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