Recovery of metal components from sulfide mineral tailings by microbial fuel cell

Patent metadata

Field	Value
Publication number	US-9755261-B2
Application number	US-201514843303-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 2, 2015
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

The present invention provides a novel method that recovers metal components from sulfide mineral tailings by Microbial Fuel Cell. The traditional bio-hydrometallurgy reaction is split to one oxidization reaction taking place in the anode chamber and one reduction reaction taking place in the cathode chamber. H + generated during the oxidization reaction is continually transferred to cathode chamber through proton exchange membrane and reacted with O 2 to generate H 2 O, which not only increases the reaction rate in anode chamber but also decreases equipment corrosion caused by excessive H + . The method of the present invention, recovering metals as well as electronic power, is environment-friendly.

First claim

What is claimed is:

1. A method for recovering metal iron from sulfide mineral tailings, comprising adding said sulfide mineral tailings to a Double-chambered Microbial Fuel Cell (MFC) and producing free iron with a high recovering rate, wherein said Double-chambered Microbial Fuel Cell comprises a cathode and an anode chamber separated by a proton exchange membrane, and electrodes in said anode and said cathode chambers connected through an external circuit; wherein said anode chamber contains said sulfide mineral tailings, an electrode and an electricigens culture comprising Sulfur-Oxidizing bacteria and Acidithiobacillus ferrooxidans ; wherein initial pH of said anode chamber is 1.5˜2.5 and anaerobic condition is maintained in said anode chamber; wherein said cathode chamber contains a phosphate buffer, an electrode and an aerator; and wherein the reaction in said Double-chambered MFC is depicted with equations below:
FeS+6Fe 3+ +0.5O 2 +3H 2 O→7Fe 2+ +SO 4 2− +6H +

anode: FeS+6Fe 3+ +4H 2 O →7Fe 2+ +8H + +SO 4 2− +2e −

cathode: 2.25O 2 +9H + +9e − →4.5H 2 O

or
FeS+2O 2 →Fe 2+ +SO 4 2−

anode: FeS+4H 2 O →Fe 2+ +SO 4 2− +8H + +8e −

cathode: 2O 2 +8H + +8e − →4H 2 O

2. The method of claim 1 , wherein said electrodes in said cathode and said anode chamber are made of graphite felt or carbon cloth.

3. The method of claim 1 , wherein said anode chamber contains 5˜50 g/L sulfide mineral tailings.

4. The method of claim 1 , wherein said phosphate buffer in said cathode chamber contains 50 mM phosphate salt (pH 7.0).

5. A Double-chambered Microbial Fuel Cell device for recovering iron metal from sulfide mineral tailings, comprising a cathode and an anode chamber separated by a proton exchange membrane, and electrodes in said anode and said cathode chamber connected through an external circuit, wherein said anode chamber contains said sulfide mineral tailings, an electrode and an electricigens culture comprising Sulfur-Oxidizing bacteria and Acidithiobacillus ferrooxidans ; wherein initial pH of said anode chamber is 1.5˜2.5 and anaerobic condition is maintained in said anode chamber; wherein said cathode chamber contains a phosphate buffer, an electrode and an aerator; and wherein the reaction in said Double-chambered MFC is depicted with equations below:
FeS+6Fe 3+ +0.5O 2 +3H 2 O→7Fe 2+ +SO 4 2− +6H +

anode: FeS+6Fe 3+ +4H 2 O →7Fe 2+ +8H + +SO 4 2− +2e −

cathode: 2.25O 2 +9H + +9e − →4.5H 2 O

or
FeS+2O 2 →Fe 2+ +SO 4 2−

anode: FeS+4H 2 O→Fe 2+ +SO 4 2− +8H + +8e −

cathode: 2O 2 +8H + +8e −→ 4H 2 O

Assignees

• Li Xiufen
• Nie Pengfei
• Ren Yueping
• Wang Xinhua
• Univ Jiangnan

Inventors

• Li Xiufen
• Nie Pengfei
• Ren Yueping
• Wang Xinhua

Classifications

• H01M8/16 Primary

  Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts · CPC title

• Y02P10/20

  Recycling · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• Y02E60/50

  Fuel cells · CPC title

• C22B3/18

  with the aid of microorganisms or enzymes, e.g. bacteria or algae · CPC title