Method for leaching precious metal contained in decopperized anode slime

Patent metadata

Field	Value
Publication number	US-10151015-B2
Application number	US-201515536280-A
Country	US
Kind code	B2
Filing date	Dec 24, 2015
Priority date	Dec 25, 2014
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A method of leaching a precious metal contained in decopperized anode slime includes, agitating and circulating a slurry at the same time, in carrying out hydrochloric acid oxidation leaching of the precious metal contained in the decopperized anode slime by adding a hydrochloric acid and an oxidant to the slurry of the decopperized anode slime, wherein in the circulating, the slurry is extracted from a lower portion of a tank and supplied again into an upper portion of the tank.

First claim

The invention claimed is:

1. A method of carrying out hydrochloric acid oxidation leaching of a precious metal contained in decopperized anode slime, comprising:
adding a hydrochloric acid and an oxidant to a slurry of the decopperized anode slime; and
agitating and circulating the slurry at the same time,
wherein, in the circulating, the slurry is extracted from a lower portion of a tank and supplied again into an upper portion of the tank, and
wherein the slurry is circulated in a case where an oxidation-reduction potential of the slurry is 650 mV to 950 mV.

2. The method of carrying out hydrochloric acid oxidation leaching of a precious metal contained in decopperized anode slime, according to claim 1 ,
wherein the oxidant is added by a fixed amount each time to the slurry of decopperized anode slime in the presence of a hydrochloric acid, such that the circulating is started when the oxidation-reduction potential of the slurry is higher than 650 mV, and the circulating is terminated when the oxidation-reduction potential of the slurry reaches 950 mV.

3. The method of carrying out hydrochloric acid oxidation leaching of a precious metal contained in decopperized anode slime, according to claim 1 , wherein 1 to 10 mass % of the slurry with respect to a total amount of the slurry is extracted per hour to circulate the slurry.

4. The method of carrying out hydrochloric acid oxidation leaching of a precious metal contained in decopperized anode slime, according to claim 1 , wherein the hydrochloric acid oxidation leaching is performed in a case where a solid component concentration is 350 to 500 g/L and a chlorine concentration is 2 to 4 mol/L in the slurry.

5. The method of carrying out hydrochloric acid oxidation leaching of a precious metal contained in decopperized anode slime, according to claim 1 ,
wherein the hydrochloric acid oxidation leaching is performed at a liquid temperature of 70° C. to 80° C.

Assignees

• Mitsubishi Materials Corp

Inventors

• SATOU Ryousuke
• Uno Takahiro
• Okada Satoshi

Classifications

• C22B11/04 Primary

  by wet processes (extraction of metal compounds by leaching in organic solutions C22B3/16; treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title

• C22B7/006

  Wet processes · CPC title

• C22B3/10

  Hydrochloric acid {, other halogenated acids or salts thereof} · CPC title

• C22B11/042 Primary

  Recovery of noble metals from waste materials · CPC title

• C25C1/12

  of copper · CPC title