# US 2022/0033985 A1 · Systems and methods for the electrochemical conversion of chalcopyrite to enable hydrometallurgical extraction of copper

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- Number: US 2022/0033985 A1
- Document ID: US20220033985A1
- Status: Published application
- Kind: A1
- Application number: 17/390,087
- Filed: 2021-07-30
- Published: 2022-02-03
- Earliest claimed: 2020-07-30
- Assignees: The Trustees of Columbia University in the City of New York
- Applicants: The Trustees of Columbia University In the City of New York
- Inventors: Alan WEST; Scott BANTA; Jon VARDNER; Campbell DONNELLY; Zhengyan ZHANG
- Web page: https://patentgrep.com/patent/US20220033985A1

## CPC

- C25B 15/081: {Supplying products to non-electrochemical reactors that are combined with the electrochemical cell, e.g. Sabatier reactor}
- C22B 3/045: {Leaching using electrochemical processes}
- C22B 15/0004: {without modification of the copper constituent}
- C22B 15/0063: {Hydrometallurgy}
- C25B 1/01: Products
- C25B 9/47: {comprising static bed electrodes}
- C25B 11/037: Electrodes made of particles
- C25B 11/042: Electrodes formed of a single material
- C25B 13/02: characterised by shape or form
- C25B 13/08: based on organic materials
- Y02P 10/20: Recycling
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

An electrochemical system and process are provided to convert an amount of chalcopyrite (CuFeS2) to a product including copper ions. In an electrochemical reactor, a potential is applied across an anode and a cathode to convert the chalcopyrite to an intermediate, chalcocite (Cu2S). The anode is covered to prevent contact with the intermediate, thus limiting subsequent conversion of the intermediate to covellite (CuS) in favor of conversion to a material more suited to chemical oxidation, cuprite (Cu2O). For example, the anode can be covered with one or more layers of filter paper. Upon application of an oxidizing agent, the cuprite is oxidized to produce a product including copper ions. The cathode and covered anode allow for efficient and inexpensive processing. The cost of this technique is comparable to industry standards, and moreover, has a much smaller environmental footprint than heat-based copper extraction.

## Claims

### Claim 1

A method for production of copper ions, comprising:
providing a sample including an amount of chalcopyrite (CuFeS2);
providing an electrochemical reactor including an anode, a cathode, and an electrolyte in communication with the anode and the cathode,
providing the sample to the electrochemical reactor;
applying a potential between the anode and the cathode to produce a first product including cuprite (Cu2O); and
applying an oxidizing agent to the first product to oxidize the Cu2O to produce a second product including copper ions.

### Claim 2 (depends on 1)

The method according to claim 1, wherein a porous separator is positioned between the sample and the anode.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the anode is covered by the porous separator.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the porous separator includes filter paper.

### Claim 5 (depends on 1)

The method according to claim 1, wherein:
the cathode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof, and
the anode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the cathode further comprises a bed of cathode material particles.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the ratio of cathode surface area (cm2) to electrochemical reactor volume (mL) is above about 0.15.

### Claim 8 (depends on 1)

The method according to claim 1, wherein applying a potential between the anode and the cathode to produce a first product including cuprite (Cu2O) includes:
operating the electrochemical reactor at a current density less than about 50 mA/cm2.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the oxidizing agent includes a source of Fe3+ ions.

### Claim 10 (depends on 1)

The method according to claim 1, wherein providing a sample including an amount of CuFeS2 further comprises:
grinding the sample to have an average particle size between about 50 μm and about 110 μm.

### Claim 11

A system for production of copper ions, comprising:
a source of chalcopyrite (CuFeS2);
an electrochemical reactor in communication with the source of CuFeS2, the electrochemical reactor including:
an anode covered by a porous separator;
a cathode;
an electrolyte in communication with the anode and the cathode; and
at least one product outlet,
a first product stream in communication with the at least one product outlet, the first product stream including cuprite (Cu2O);
a source of Fe3+ ions in communication with the first product stream; and
a second product stream in communication with the first product stream, the second product stream including copper ions.

### Claim 12 (depends on 11)

The system according to claim 11, wherein the ratio of cathode surface area (cm2) to electrochemical reactor volume (mL) is above about 0.15.

### Claim 13 (depends on 11)

The system according to claim 11, wherein:
the cathode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof, and
the anode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof.

### Claim 14 (depends on 11)

The system according to claim 11, wherein the cathode further comprises a bed of cathode material particles.

### Claim 15 (depends on 11)

The system according to claim 11, wherein the electrochemical reactor is operated at a current density less than about 50 mA/cm2.

### Claim 16

A system for production of copper ions, comprising:
a source of chalcopyrite (CuFeS2);
a source of Fe3+ ions;
an electrochemical reactor in communication with the source of CuFeS2 and the source of Fe3+ ions, the electrochemical reactor including:
an anode;
a cathode;
an electrolyte in communication with the anode and the cathode;
a potentiostat; and
at least one product outlet,
and,
a product stream in communication with the at least one product outlet, the product stream including copper ions,
wherein the ratio of cathode surface area (cm2) to reactor volume (mL) is above about 0.15, and the potentiostat operates the electrochemical reactor at a current density less than about 50 mA/cm2.

### Claim 17 (depends on 16)

The system according to claim 16, wherein a porous separator is positioned to isolate the anode from contact with the CuFeS2.

### Claim 18 (depends on 17)

The system according to claim 17, wherein the anode is covered by at least one layer of filter paper.

### Claim 19 (depends on 16)

The system according to claim 16, wherein:
the cathode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof, and
the anode is composed of niobium, tungsten, platinum, copper, aluminum, lead, or combinations thereof.

### Claim 20 (depends on 16)

The system according to claim 16, wherein the cathode further comprises a bed of cathode material particles.