# US 2013/0156631 A1 · Method of removing oxide film on surface of copper or copper-base alloy and copper or copper-base alloy recovered using the method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156631 A1 - Document ID: US20130156631A1 - Status: Published application - Kind: A1 - Application number: 13/714,746 - Filed: 2012-12-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: Mitsubishi Materials Corporation - Inventors: Jyunichi Kumagai; Yoshie Tarutani; Hiroaki Nakayama; Kenzi Okada; Naoki Kato; Kenji Kubota - Web page: https://patentgrep.com/patent/US20130156631A1 ## CPC - C25F 1/04: in solution - C23G 1/103: {copper or alloys of copper} - C23G 1/36: Regeneration of waste pickling liquors - C25C 1/12: of copper - Y02P 10/20: Recycling - C25F: PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR - C23G: CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS - C25C: PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A pickling solution, including: 50 g/L to 400 g/L of sulfuric acid; 1 g/L to 100 g/L of at least one oxidant selected from a group consisting of nitric acid, hydrogen peroxide, peroxodisulfate ions, and iron (III) ions; 0.01 g/L to 10 g/L of at least one additive selected from a group consisting of aromatic sulfonic acid, aromatic sulfonate, alkylamine, aromatic carboxylic acid, and aromatic carboxylate; 0.005 g/L to 10 g/L of at least one surfactant selected from a group consisting of alkylbenzene sulfonic acid and alkylbenzene sulfonate; and 10 g/L to 300 g/L of copper sulfate, is used to remove oxide film, and then reused by being electrolyzed and adding the oxidant, the additive and the surfactant in amounts equivalent to consumed amounts. ## Claims ### Claim 1 A method of removing oxide film formed on a surface of a copper or copper-base alloy, the method comprising steps of: dipping a copper or copper-base alloy having oxide film formed on a surface thereof, to remove the oxide film, in a pickling bath which contains a pickling solution including: 50 g/L to 400 g/L of sulfuric acid; 1 g/L to 100 g/L of at least one oxidant selected from a group consisting of nitric acid, hydrogen peroxide, peroxodisulfate ions, and iron (III) ions; 0.01 g/L to 10 g/L of at least one additive selected from a group consisting of aromatic sulfonic acid, aromatic sulfonate, alkylamine, aromatic carboxylic acid, and aromatic carboxylate; 0.005 g/L to 10 g/L of at least one surfactant selected from a group consisting of alkylbenzene sulfonic acid and alkylbenzene sulfonate; and 10 g/L to 300 g/L of copper sulfate; electrolyzing the pickling solution containing the removed oxide film in an electrolytic bath so as to recover a copper or copper-base alloy from the oxide film; adding the oxidant, the additive, and the surfactant to the electrolyzed pickling solution in amounts equivalent to those consumed when the oxide film is removed and when the electrolysis is performed; and returning the electrolyzed pickling solution, to which the oxidant, the additive, and the surfactant are added, to the pickling bath to be reused as a new pickling solution. ### Claim 2 (depends on 1) The method of removing oxide film on a surface of a copper or copper-base alloy according to claim 1, wherein a surface tension of the pickling solution is less than or equal to 50×10−3 N/m. ### Claim 3 (depends on 1) The method of removing oxide film on a surface of a copper or copper-base alloy according to claim 1, further comprising steps of: in the electrolyzing step, adjusting a concentration of copper ions in the pickling solution containing the removed oxide film is 20 g/L to 60 g/L; controlling a current density in a range of 1 A/dm2 to 25 A/dm2; and rotating a cathode having a cylindrical body at a peripheral speed in a range of 0.08 m/s to 0.48 m/s. ### Claim 4 (depends on 2) The method of removing oxide film on a surface of a copper or copper-base alloy according to claim 2, further comprising steps of: in the electrolyzing step, adjusting a concentration of copper ions in the pickling solution containing the removed oxide film is 20 g/L to 60 g/L; controlling a current density in a range of 1 A/dm2 to 25 A/dm2; and rotating a cathode having a cylindrical body at a peripheral speed in a range of 0.08 m/s to 0.48 m/s. ### Claim 5 (depends on 3) The method of removing oxide film on a surface of a copper or copper-base alloy according to claim 3, wherein in the electrolyzing, the flow rate of the pickling solution supplied to the electrolytic bath and the current density in the electrolytic bath are adjusted such that the concentration of copper ions in the pickling solution containing the removed oxide film is 20 g/L to 60 g/L. ### Claim 6 (depends on 4) The method of removing oxide film on a surface of a copper or copper-base alloy according to claim 4, wherein in the electrolyzing, a flow rate of the pickling solution supplied to the electrolytic bath is adjusted such that a concentration of copper ions in the pickling solution containing the removed oxide film is 20 g/L to 60 g/L. ### Claim 7 (depends on 1) A copper or copper-base alloy which is recovered using the method of removing oxide film on a surface of a copper or copper-base alloy according to claim 1 and is capable of being used as a recycled material.