Method for extracting metal compound particles, method for analyzing the metal compound particles, and electrolytic solution used therefor

Patent metadata

Field	Value
Publication number	US-2020141023-A1
Application number	US-201715999826-A
Country	US
Kind code	A1
Filing date	Feb 17, 2017
Priority date	Feb 18, 2016
Publication date	May 7, 2020
Grant date	—

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.
A method for extracting metal compound particles in a metal material by etching the metal material in an electrolytic solution, characterized by using the following electrolytic solution,
wherein it comprises a chemical agent that forms a complex containing metal M′ wherein Δ 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 metal compound to be extracted MxAy, which is contained in the metal material, is defined as Ksp└MxAy┘, as well as the electrolytic solution therefor.

First claim

1 . A method for extracting metal compound particles in a metal material by etching the metal material in an electrolytic solution, characterized by using the following, electrolytic solution,
wherein it comprises a chemical agent that forms a complex containing metal M′ wherein Δ 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 metal compound to be extracted MxAy, which is contained in the metal material, is defined as Ksp[MxAy], and
wherein M and M′ are different metal elements, A is a single atom or atomic group 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 the solubility product Ksp is a value in an aqueous solution at 25° C.

2 . The method for extracting metal compound particles according to claim 1 , wherein the electrolytic solution is a nonaqueous solvent-based electrolytic solution.

3 . The method for extracting metal compound particles according to claim 1 or 2 , wherein the metal compound to be extracted MxAy is one or two of MnS and FeS.

4 . The method for extracting metal compound particles according to any one of claims 1 to 3 , wherein the metal M′ of the metal compound M′x′Ay′ whose pKsp is greater, is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni.

5 . The method for extracting metal compound particles according to any one of claims 1 to 4 , wherein the chemical agent comprises a crown ether.

6 . The method for extracting metal compound particles according to any one of claims 1 to 5 , wherein the chemical agent comprises any one kind or two or more kinds of polyethylene amines, ethylenediamine tetraacetic acid, cyclohexanediamine tetraacetic acid.

7 . The method for extracting metal compound particles according to claim 6 , wherein the chemical agent comprises triethylenetetramine.

8 . The method for extracting metal compound particles according to any one of claims 1 to 7 , wherein the metal material is a steel material.

9 . The method for extracting metal compound particles according to any one of claims 1 to 8 , wherein, when passing the electrolytic solution after etching through a filter and extracting metal compound particles as a collected residue, the filter is a tetrafluoroethylene resin filter.

10 . A method for analyzing metal compound particles characterized by analyzing the metal compound particles extracted by the method for extracting metal compound particles according to any one of claims 1 to 9 .

11 . An electrolytic solution used for extracting metal compound particles in a metal material by etching the metal material,
wherein the electrolytic solution comprises a chemical agent that forms a complex containing metal M′ wherein Δ 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 metal compound to be extracted MxAy contained in the metal material is defined as Ksp[MxAy], and
wherein M and M′ are different metal elements, A is a single atom or atomic group forming a compound with M or M′, and x, x′, y and y′ represent a composition ratio of the compound determined according to the valence of M, M′ and A, and the solubility product Ksp is a value in an aqueous solution at 25° C.

12 . The electrolytic solution according to claim 11 , wherein it is a nonaqueous solvent system.

13 . The electrolytic solution according to claim 11 or 12 , wherein the metal compound to be extracted MxAy is one or two of MnS or FeS.

14 . The electrolytic solution according to any one of claims 11 to 13 , wherein the metal M′ of the metal compound M′x′Ay′ whose solubility product Ksp is smaller, is at least one of Hg, Ag, Cu, Pb, Cd, Co, Zn and Ni.

15 . The electrolytic solution according to any one of claims 11 to 14 , wherein the chemical agent comprises a crown ether.

16 . The electrolytic solution according to any one of claims 11 to 15 , wherein the chemical agent comprises any one kind or two or more kinds of polyethylene amines, ethylenediamine tetraacetic acid, cyclohexanediamine tetraacetic acid.

17 . The electrolytic solution according to claim 16 , wherein the chemical agent comprises triethylenetetramine.

18 . The electrolytic solution according to any one of claims 11 to 17 , wherein the metal material is a steel material.

19 . The electrolytic solution according to any one of claims 11 to 18 , wherein the nonaqueous solvent contains at least one of methanol and ethanol.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Mizukami Kazumi

Classifications

• C25F5/00

  Electrolytic stripping of metallic layers or coatings · CPC title

• C25F3/02 Primary

  Etching · CPC title

• G01N1/32 Primary

  Polishing; Etching · CPC title

• G01N33/202

  Constituents thereof · CPC title

• C09K13/00

  Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40}) · CPC title