# US 11,111,595 B2 · Apparatus for electrolytic etching and dissolution and method for extracting metal compound particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,111,595 B2 - Document ID: US11111595B2 - Status: Granted - Kind: B2 - Application number: 15/999,791 - Filed: 2017-02-17 - Published: 2020-05-07 - Granted: 2021-09-07 - Earliest claimed: 2016-02-18 - Assignees: Nippon Steel Corporation - Applicants: Nippon Steel & Sumitomo Metal Corporation - Inventors: Kazumi Mizukami - Web page: https://patentgrep.com/patent/US11111595B2 ## CPC - C25F 3/02: Etching - C25F 3/06: of iron or steel - C25F 7/00: Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects (for both electrolytic coating and removal C25D); Servicing or operating - G01N 1/32: Polishing; Etching - G01N 1/40: Concentrating samples - G01N 33/2028: Metallic constituents - G01N 2001/4038: {electric methods, e.g. electromigration, electrophoresis, ionisation} - Y02P 10/20: Recycling - C25F: PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The object of the present invention is such that a surface exchange of metal fine particles by Cu ions, or the like is inhibited in order to prevent formation of Artificial CuS or the like, in extraction and analysis of the metal fine particles (inclusions and precipitates) in a metal material by electrolytic corrosion in a solvent-based electrolytic solution, without significantly changing conventional extraction and analysis methods, and such that the metal deposited on the cathode is actively attached to the cathode so that the deposited metal does not become a contamination source. An apparatus for electrolytic etching and dissolution and an extraction method for separation and extraction of metal compound particles in a metal material, wherein at least a part of the cathode comprises a material consisting of a metal M′ whose Δ defined by the following formula is 10 or more, and the apparatus comprises an electrolytic cell for containing an electrolytic solution comprising a chemical agent that forms a complex containing the metal M′ and a nonaqueous solvent, Δ = pKsp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] - pKsp ⁡ [ MxAy ] = ( - log 10 ⁢ Ksp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] ) - ( - log 10 ⁢ Ksp ⁡ [ MxAy ] ) . ## Claims ### Claim 1 An apparatus for electrolytic etching and dissolution, the apparatus comprising: an electrolytic cell comprising an anode, a cathode and an electrolytic solution comprising a chemical agent and a nonaqueous solvent; wherein the chemical agent comprises at least one of a polyethylene amine, ethylenediamine tetraacetic acid and cyclohexanediamine tetraacetic acid, and the nonaqueous solvent comprises at least one of methanol, ethanol and isopropyl alcohol; wherein at least a part of the cathode comprises a metal element M′, the anode comprises a metal material including a different metal element M; wherein the metal element M′ whose A is defined by the following formula is 10 or more: Δ = pKsp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] - pKsp ⁡ [ MxAy ] = ( - log 10 ⁢ Ksp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] ) - ( - log 10 ⁢ Ksp ⁡ [ MxAy ] ) wherein a solubility product of metal compound M′x′Ay′ is defined as Ksp[M′x′Ay′], and a solubility product of a metal compound to be extracted from the anode is MxAy, defined as Ksp[MxAy], the solubility product Ksp is a value in an aqueous solution at 25° C.; and A consists of one or more of C, N, H, S, O, P, Se, Te and F for forming a compound with M or M′, and x, x′, y and y′ represent a composition ratio of the compound determined according to the valences of M, M′ and A; and electrolytically etching the anode to extract the metal compound MxAy by electrifying between the anode and the cathode. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the metal element M′ is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the metal compound MxAy is at least one of FeS and MnS. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the metal element M′ is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the metal element M′ is provided to cover a surface of the cathode. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the cathode consists of the metal element M′. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the metal element M′ consists of 99.9% or more of copper by mass. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the polyethylene amine of the chemical agent comprises triethylenetetramine. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the apparatus further comprises a stirring means for the electrolytic solution. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the stirring means is a gas bubble generator. ### Claim 11 A method for extracting metal compound particles in a metal material, the method comprising: providing an electrolytic cell comprising an anode, a cathode and an electrolytic solution comprising a chemical agent and a nonaqueous solvent; wherein the chemical agent comprises at least one of a polyethylene amine, ethylenediamine tetraacetic add and cyclohexanediamine tetraacetic add, and the nonaqueous solvent comprises at least one of methanol, ethanol and isopropyl alcohol; wherein at least a part of the cathode comprises a metal dement M′, the anode comprises the metal material including a different metal demerit M; wherein the metal dement M whose A is defined by the following formula is 10 or more: Δ = pKsp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] - pKsp ⁡ [ MxAy ] = ( - log ⁢ ⁢ 10 ⁢ Ksp ⁡ [ M ′ ⁢ x ′ ⁢ Ay ′ ] ) - ( - log ⁢ ⁢ 10 ⁢ Ksp [ MxAy ) ] wherein a solubility product of metal compound M′x′Ay′ is defined as Ksp[M′x′Ay′], and a solubility product of a metal compound to be extracted from the anode is MxAy, defined as Ksp[MxAy], the solubility product Ksp is a value in an aqueous solution at 25° C.; and A consists of one or more of C, N, H, S, O, P, Se, Te and F for forming a compound with M or M′, and x, x′, y and y represent a composition ratio of the compound determined according to the valences of M, M′ and A; and electrolytically etching the anode to extract the metal compound MxAy by electrifying between the anode and the cathode. ### Claim 12 (depends on 11) The method of claim 11, wherein the metal element M′ is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni. ### Claim 13 (depends on 11) The method of claim 11, wherein the metal compound MxAy is at least one of FeS and MnS. ### Claim 14 (depends on 13) The method of claim 13, wherein the metal element M′ is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni. ### Claim 15 (depends on 11) The method of claim 11, wherein the metal element M′ is provided to cover a surface of the cathode. ### Claim 16 (depends on 11) The method of claim 11, wherein the cathode consists of the metal element M′. ### Claim 17 (depends on 16) The method of claim 16, wherein the metal element M′ consists of 99.9% or more of copper by mass. ### Claim 18 (depends on 11) The method of claim 11, wherein the polyethylene amine of the chemical agent comprises triethylenetetramine. ### Claim 19 (depends on 11) The method of claim 11, wherein the electrolytic solution is stirred during the electrolytic etching process. ### Claim 20 (depends on 19) The method of claim 19, wherein the stirring is performed by a magnetic stirrer or a gas bubble generator.