Sulfonate electroplating baths, methods for refining metals by electrolytic deposition and methods for controlling metal morphology in electrorefining - Patents.com

Abstract

The present invention relates to an electroplating bath comprising (A) an alkane sulfonic acid or alkanol sulfonic acid, (B) a soluble metal salt of an alkane sulfonic acid or alkanol sulfonic acid, and (C) at least one additive selected from - a polyether derivative of formula (I), - a sulfonated or sulfated polyether derivative of formula (II) or - any combination thereof, wherein the groups in formulas (I) and (II) are as defined in the description and claims. The present invention also relates to a method for purifying metals and a method for controlling the morphology of metals deposited on a cathode in the electrorefining of metals, which comprises using an electroplating bath according to the present invention. [Formula 1] JPEG2024519368000016.jpg19170 [C2] JPEG2024519368000017.jpg19170

Description

[Technical field]

[0001] The present invention relates to metal sulfonate-based electroplating baths, methods for refining crude metals by electrolytic deposition in electroplating baths, and methods for controlling metal morphology in electrorefining. [Background technology]

[0002] Crude lead has been commercially refined by pyrorefining or electrorefining to provide high purity lead and in some cases for the recovery of precious metals. In recent decades, electrorefining of crude lead has been adopted by more and more countries and regions due to its advantages of less environmental damage, higher refining efficiency and recovery of precious metals.

[0003] Traditionally, an acidic aqueous solution containing lead fluoroborate or fluorosilicate has been widely used as an electroplating bath for electrolytically refining crude lead, but it has low thermal stability and high level of volatility, which inevitably brings about harmful effects on health and adverse effects on production equipment, so that safe and efficient operation cannot be achieved. The process for electrolytically refining other metals such as tin also has the same problem.

[0004] Recently, fluorine-free acidic aqueous solutions have been developed as replacements for electroplating baths containing fluoroborates or fluorosilicates. For example, CN104746908A describes a process for electrorefining lead using an aqueous electrolyte containing lead methanesulfonate and methanesulfonic acid. The electrolyte also contains one or more additives selected from animal glue, lignosulfonates, aloin, and β-naphthol.

[0005] The electrorefining process using a methanesulfonate-based electroplating bath described in CN 104746908A successfully overcomes the toxicity and pollution drawbacks of fluoroborate or fluorosilicate-based electroplating baths.

[0006] However, it has been found by the inventors of the present invention that the process described in CN104746908A cannot provide the desired appearance or morphology of the lead deposit on the cathode. The lead deposit is observed to have a rough or non-dense surface with burrs, dendrites or scales on the edges, and this prevents the application of the process on a commercial scale, since the defects in appearance or morphology, especially the dendrites, may sometimes cause a short circuit before obtaining a sufficient amount of product deposit in the electrolyte tank.

[0007] There is a further need for fluorine-free electroplating baths suitable for electrorefining metals with improved appearance or morphology of the deposited metal and therefore with desirable efficiency. Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to provide sulfonate-based, fluorine-free electroplating baths that are useful for electrorefining metals to obtain metal deposits on cathodes with desirable appearances or morphologies.

[0009] It is another object of the present invention to provide an electrorefining process which has improved overall process economics and can be performed with flexible process conditions.

[0010] It has now been found that the objects of the present invention can be achieved by an electroplating bath comprising an additive selected from phenol and naphthol polyether derivatives and sulfated or sulfonated phenol and naphthol polyether derivatives. [Means for solving the problem]

[0011] Thus, in one aspect, the present invention comprises: (A) an alkane sulfonic acid or an alkanol sulfonic acid, (B) a soluble metal salt of an alkane sulfonic acid or an alkanol sulfonic acid; (C) The following: - Formula (I) [ka] (In the formula, Ar is C3-C 12 -phenyl substituted by alkyl, or naphthyl, which is unsubstituted or substituted by C1-C4-alkyl; E1 and E2 are different from each other and are selected from ethyleneoxy and propyleneoxy; m is 0 or a number in the range of 1 to 40; n is a number ranging from 1 to 40; - Formula (II) [ka] (In the formula, Ar' is C3~C 12 -phenyl substituted by alkyl and optionally by the group -SO3M, or naphthyl which is unsubstituted or substituted by C1-C4-alkyl and / or -SO3M groups, E1' and E2' are different alkyleneoxy groups selected from ethyleneoxy and propyleneoxy; E3 is the alkylene portion of E2; m' is 0 or a number in the range of 1 to 40; o is 0 or 1; the sum of n'+o is a number in the range of 1 to 40, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these and at least one additive selected from the group consisting of:

[0012] In another aspect, the present invention provides a method for purifying a metal comprising electrolytically depositing a metal in an electroplating bath comprising: (A) an alkane sulfonic acid or an alkanol sulfonic acid; (B) a soluble metal salt of an alkane sulfonic acid or an alkanol sulfonic acid; and (C) at least one additive selected from a polyether derivative, a sulfonated or sulfated polyether derivative, or any combination thereof, as described herein.

[0013] In yet another aspect, the present invention provides a method for controlling the morphology of a metal, particularly lead, deposited on a cathode in the electrorefining of a metal comprising using an electroplating bath comprising: (A) at least one soluble metal salt of an alkane sulfonic acid or alkanol sulfonic acid; (B) at least one soluble alkane sulfonate or alkanol sulfonate salt of a metal; and (C) at least one additive selected from the polyether derivatives, sulfonated or sulfated polyether derivatives described herein, or any combination thereof.

[0014] In a further aspect, the present invention provides the use of the polyether derivatives, sulfonated or sulfated polyether derivatives, or any combination thereof, as described herein, in electroplating baths for purifying metals, in particular lead and / or tin. [Brief description of the drawings]

[0015] [Figure 1] 1 shows a morphology image of deposited lead according to Comparative Example 1, which does not use any additives in the electroplating bath. [Figure 2A-B] 4 shows morphology and SEM images of lead deposited according to Comparative Example 2 using bone glue as an additive in the electroplating bath. [Diagram 3] FIG. 2 shows a morphology image of deposited lead according to Comparative Example 3 using calcium lignosulfonate as an additive in the electroplating bath. [Figure 4]4 shows a morphology image of deposited lead according to Comparative Example 4 using bone glue and calcium lignosulfonate as additives in the electroplating bath. [Figure 5A-B] 4 shows morphology and SEM images of lead deposited according to Comparative Example 5 using β-naphthol as an additive in the electroplating bath. [Figure 6A-B] 1 shows morphology and SEM images of lead deposited according to Example 1 of the present invention using β-naphthol ethoxylate (12EO) and calcium lignosulfonate as additives in the electroplating bath. [Figure 7A-B] 1 shows morphology and SEM images of deposited lead according to Example 2 of the present invention using β-naphthol ethoxylate (12EO) and sulfonate-substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) as additives in an electroplating bath. [Figure 8A-B] 1 shows morphology and SEM images of deposited lead according to Example 3 of the present invention using calcium lignosulfonate and sulfonate-substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) as additives in the electroplating bath. [Figure 9A-B] FIG. 1 shows morphology and SEM images of lead deposited according to Example 4 of the present invention using calcium lignosulfonate, sulfonate substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) and β-naphthol ethoxylate (12EO) as additives in the electroplating bath. [Figure 10A-B] 4 shows morphology and SEM images of deposited lead according to Example 3 of the present invention using calcium lignosulfonate and β-naphthol ethoxylate (12EO) as additives in the electroplating bath. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will now be described in detail below. It should be understood that the present invention can be embodied in many different ways and should not be construed as being limited to the embodiments set forth herein. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0017] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0018] As used herein, the terms "comprise", "comprising", and the like are used interchangeably with "contain", "containing", and the like, and are to be interpreted in an open, non-limiting manner. That is, for example, additional components or elements may be present. Expressions such as "consists of" or "consists essentially of" may be included in "comprises", and the like.

[0019] As used herein, the term "aqueous" means that the electroplating bath comprises a solvent that includes at least 50% water. Preferably, at least 75% of the solvent is water, more preferably 90%. The solvent of the electroplating bath can be expected to consist essentially of water without any intentionally added organic solvents. Any type of water can be used, such as distilled water, deionized water, or tap water.

[0020] <Electroplating bath> In a first aspect, the present invention provides a method for producing a pharmaceutical composition comprising: (A) an alkane sulfonic acid or an alkanol sulfonic acid, (B) a soluble metal salt of an alkane sulfonic acid or an alkanol sulfonic acid; (C) The following: - Formula (I) [ka] (In the formula, Ar is C3-C 12 -phenyl substituted by alkyl, or naphthyl, which is unsubstituted or substituted by C1-C4-alkyl; E1 and E2 are different from each other and are selected from ethyleneoxy and propyleneoxy; m is 0 or a number in the range of 1 to 40; n is a number ranging from 1 to 40; - Formula (II) [ka] (In the formula, Ar' is C3~C 12 -phenyl substituted by alkyl and optionally by the group -SO3M, or naphthyl which is unsubstituted or substituted by C1-C4-alkyl and / or -SO3M groups, E1' and E2' are different alkyleneoxy groups selected from ethyleneoxy and propyleneoxy; E3 is the alkylene portion of E2; m' is 0 or a number in the range of 1 to 40; o is 0 or 1; the sum of n'+o is a number in the range of 1 to 40, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these and at least one additive selected from the group consisting of:

[0021] Alkanesulfonic acids useful as component (A) are C1-C 12The alkane sulfonic acid may be a C1-C6-alkane sulfonic acid, preferably a C1-C6-alkane sulfonic acid. Examples of alkane sulfonic acids include, but are not limited to, methane sulfonic acid, ethane sulfonic acid, propane sulfonic acid, 2-propane sulfonic acid, butane sulfonic acid, 2-butane sulfonic acid, pentane sulfonic acid, hexane sulfonic acid, decane sulfonic acid, and dodecane sulfonic acid. One alkane sulfonic acid or any mixture of two or more alkane sulfonic acids may be used in the electroplating bath according to the present invention.

[0022] Alkanol sulfonic acids useful as component (A) are C2-C 12 -alkanolsulfonic acids, preferably C2-C6-alkanolsulfonic acids, i.e., hydroxy-substituted C2-C 12 -, preferably C2-C6-alkanesulfonic acids. The hydroxyl can be on the terminal or internal carbon of the alkyl chain of the alkane sulfonic acid. Examples of useful alkanol sulfonic acids include, but are not limited to, 2-hydroxyethane-1-sulfonic acid, 1-hydroxypropane-2-sulfonic acid, 2-hydroxypropane-1-sulfonic acid, 3-hydroxypropane-1-sulfonic acid, 2-hydroxybutane-1-sulfonic acid, 4-hydroxybutane-1-sulfonic acid, 2-hydroxypentane-1-sulfonic acid, 4-hydroxypentane-1-sulfonic acid, 2-hydroxyhexane-1-sulfonic acid, 2-hydroxydecane-1-sulfonic acid, 2-hydroxydodecane-1-sulfonic acid. One alkanol sulfonic acid or any mixture of two or more alkanol sulfonic acids can be used in the electroplating bath according to the present invention.

[0023] The alkane sulfonic acids and alkanol sulfonic acids may be prepared by any method known in the art or may be commercially available, without particular limitation.

[0024] Component (A) may be included in the electroplating bath according to the present invention in a concentration ranging from 10 to 200 grams per liter (g / L), particularly from 30 to 150 g / L, and preferably from 50 to 110 g / L.

[0025] The soluble metal salt of an alkane sulfonic acid or alkanol sulfonic acid as component (B) is a salt of the metal that is deposited by electrolysis. The metal useful for the present invention may be selected from lead or tin, in particular lead. Thus, component (B) may be a soluble alkane sulfonate or alkanol sulfonate salt selected from lead or tin, in particular lead.

[0026] As used herein, the term "soluble metal salt" is intended to mean that the metal salt can be dissolved in the electroplating bath before and during electrolysis.

[0027] The soluble metal salt of an alkane- or alkanol-sulfonic acid can be derived from the same alkane- or alkanol-sulfonic acid as component (A). In particular, component (B) is a soluble metal salt of the same alkane- or alkanol-sulfonic acid used as component (A), wherein the metal is lead or tin.

[0028] For example, an electroplating bath according to the present invention may contain methanesulfonic acid as component (A) and lead(II) methanesulfonate as component (B).

[0029] Soluble metal salts of alkane sulfonic acids and alkanol sulfonic acids can be prepared by any method known in the art, such as by reaction of the oxide of the metal with the desired alkane sulfonic acid or alkanol sulfonic acid.

[0030] Component (B) may be present in the electroplating bath according to the invention in a concentration ranging from 50 to 200 g / L of bath, in particular from 70 to 150 g / L, preferably from 90 to 150 g / L, more preferably from 90 to 120 g / L, calculated as metal ions.

[0031] The electroplating bath according to the present invention comprises at least one additive selected from the polyether derivatives of formula (I), the sulfonated or sulfated polyether derivatives of formula (II), or any combination thereof. It has surprisingly been found that the at least one additive is essential for depositing metal with a desired appearance on the cathode when the electroplating bath is used in an electroplating or electrorefining process.

[0032] In some embodiments, the at least one additive (C) is preferably selected from a polyether derivative of formula (I) in which m is 0 or a number in the range of 2 to 35, and n is a number in the range of 2 to 35, a sulfonated or sulfated polyether derivative of formula (II) in which m' is 0 or a number in the range of 2 to 35, o is 0 or 1, and the sum of n'+o is a number in the range of 2 to 35, or any combination thereof.

[0033] In some embodiments, the at least one additive (C) is preferably selected from a polyether derivative of formula (I) (wherein m is 0 or a number in the range of 4 to 30, and n is a number in the range of 4 to 30), a sulfonated or sulfated polyether derivative of formula (II) (wherein m' is 0 or a number in the range of 4 to 30, o is 0 or 1, and the sum of n'+o is a number in the range of 4 to 30), or any combination thereof.

[0034] In some particular embodiments, the at least one additive (C) is preferably selected from a polyether derivative of formula (I) in which m is 0 or a number in the range of 6 to 20, and n is a number in the range of 6 to 20, a sulfonated or sulfated polyether derivative of formula (II) in which m' is 0 or a number in the range of 6 to 20, o is 0 or 1, and the sum of n'+o is a number in the range of 6 to 20, or any combination thereof.

[0035] In some preferred embodiments, the at least one additive (C) is preferably selected from a polyether derivative of formula (I) where m is 0 or a number in the range of 8 to 15, and n is a number in the range of 8 to 15, a sulfonated or sulfated polyether derivative of formula (II) where m' is 0 or a number in the range of 8 to 15, o is 0 or 1, and the sum of n'+o is a number in the range of 8 to 15, or any combination thereof.

[0036] In some exemplary embodiments, the at least one additive (C) is - Formula (I) [ka] (In the formula, Ar is C3-C 12 -phenyl substituted by alkyl, or naphthyl, which is unsubstituted or substituted by C1-C4-alkyl; E1 and E2 are different from each other and are selected from ethyleneoxy and propyleneoxy; m is 0 or a number ranging from 4 to 30; n is a number ranging from 4 to 30; - Formula (II) [ka] (In the formula, Ar' is C3~C 12 -phenyl substituted by alkyl and optionally by the group -SO3M, or naphthyl which is unsubstituted or substituted by C1-C4-alkyl and / or -SO3M groups, E1' and E2' are different alkyleneoxy groups selected from ethyleneoxy and propyleneoxy; E3 is the alkylene portion of E2; m' is 0 or a number in the range of 4 to 30; o is 0 or 1; the sum of n'+o is a number in the range of 4 to 30, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these is selected from.

[0037] In the embodiments described below, it is preferred that either or both of m in formula (I) and m' in formula (II) are 0. Thus, the at least one additive (C) is preferably selected from a polyether derivative of formula (I) in which m is 0 and n is a number in the range of 4 to 30, preferably 6 to 20, more preferably 8 to 15, a sulfonated or sulfated polyether derivative of formula (II) in which m' is 0, o is 0 or 1, and the sum of n'+o is a number in the range of 4 to 30, preferably 6 to 20, more preferably 8 to 15, or any combination thereof. In those embodiments, it is further preferred that E2 and E2' are ethyleneoxy.

[0038] In some further exemplary embodiments, the at least one additive (C) is - Formula (Ia) [ka] (In the formula, Ar is 4-(C3-C 12 -alkyl)phenyl or unsubstituted naphthyl; n is a number ranging from 4 to 30; - Formula (II) [ka] (In the formula, Ar' is 4-(C3-C4) optionally substituted with a -SO3M group. 12 -alkyl)phenyl, or naphthyl which is unsubstituted or substituted by the group -SO3M; o is 0 or 1; the sum of n'+o is a number in the range of 4 to 30, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these is selected from.

[0039] The polyether derivative according to any of the above embodiments is preferably of formula (I) or (Ia), wherein the group Ar is a C4-C 10 -phenyl substituted with alkyl, preferably 4-(C 10 -alkyl)phenyl or unsubstituted naphthyl, preferably unsubstituted β-naphthyl. More preferably, the polyether derivative is of formula (I) or (Ia), where the group Ar is unsubstituted β-naphthyl.

[0040] Alternatively or additionally, the sulfonated or sulfated polyether derivative according to any of the above embodiments is preferably of formula (II) or (IIa), where the group Ar′ is a C4-C 10 Phenyl substituted with -alkyl and -SO3M, preferably 4-(C4-C 10 -alkyl), phenyl, or naphthyl which is unsubstituted or substituted by -SO3M. More preferably, the sulfonated or sulfated polyether derivative is of formula (II) or (IIa), in which the group Ar′ is a 4-(C4-C 10 -alkyl)phenyl).

[0041] As used herein, the term “C 12 -Alkyl" and "C4-C 10"-Alkyl" means straight or branched, saturated hydrocarbyl, for example, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, and isomers thereof.

[0042] The term "propyleneoxy" as described herein can mean methyl-substituted ethyleneoxy, such as 1-methylethyleneoxy or 2-methylethyleneoxy.

[0043] In particular, the at least one additive (C) is - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 6 to 20, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is a number ranging from 6 to 20, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and Any combination of them is selected from.

[0044] More particularly, the at least one additive (C) is - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 8 to 15, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is a number ranging from 8 to 15, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these is selected from.

[0045] For example, the at least one additive (C) is - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is 10, 11, 12 or 13, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is 9, 10, 11 or 12, and M is an alkali metal cation or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these is selected from.

[0046] As used herein, suitable alkali metal cations as M in formulae (II) and (IIa) are in particular the sodium cation (Na + ) or potassium cation (K + ).

[0047] The polyether derivatives of formulae (I) and (Ia) can be prepared by any method known in the art, for example by sequential oxyalkylation of the starting substituted phenol or naphthol with an alkylene oxide such as ethylene oxide or propylene oxide, or both. Methods for the preparation of sulfonated or sulfated polyether derivatives of formulae (II) and (IIa) are also known in the art, for example by sulfonating the polyether derivatives of formulae (I) and (Ia) followed by neutralization.

[0048] The polyether derivatives and sulfonated or sulfated polyether derivatives described herein may also be commercially available, for example, from BASF.

[0049] The at least one additive (C) may each be present in the electroplating bath according to the invention in a concentration ranging from 0.5 to 5.0 g / L bath, in particular from 0.5 to 3.0 g / L.

[0050] In some embodiments, electroplating baths according to the invention can typically and preferably include, as component (C), a combination of at least one polyether derivative and at least one sulfonated or sulfated polyether derivative as described herein. When such a combination is used, the additive as component (C) can be included in the electroplating bath in a total concentration ranging from 1.0 to 5.0 g / L bath, particularly from 2.0 to 5.0 g / L.

[0051] The electroplating bath according to the invention may further comprise an additional additive (D) selected from animal glue such as bone glue, lignosulfonates, aloin and β-naphthol, in particular lignosulfonates, such as calcium lignosulfonate. The additional additive may be included in the electroplating bath in a concentration ranging from 0.1 to 2.0 g / L of bath.

[0052] In some exemplary embodiments, the present invention provides: (A) C1-C6-alkanesulfonic acid, (B) a soluble metal salt of a C1-C6-alkanesulfonic acid, the metal being selected from lead and tin, in particular lead; (C) The following: - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 6 to 20, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is a number ranging from 6 to 20, and M is an alkali metal cation or NH4 + and sulfonated or sulfated polyether derivatives of - Any combination of these At least one additive selected from and (D) optionally, an additional additive selected from animal glue, such as bone glue, lignosulfonates, aloin, and β-naphthol.

[0053] In some further exemplary embodiments, the present invention provides a method for producing (A) C1-C6-alkanesulfonic acid, (B) a soluble metal salt of a C1-C6-alkanesulfonic acid (the metal is lead); (C) The following: - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 8 to 15, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is a number ranging from 8 to 15, and M is an alkali metal cation or NH4 + and sulfonated or sulfated polyether derivatives of - any combination thereof, At least one additive selected from and (D) optionally, an additional additive selected from animal glue, such as bone glue, lignosulfonates, aloin, and β-naphthol.

[0054] In some preferred exemplary embodiments, the present invention provides: (A) methanesulfonic acid, (B) lead methanesulfonate; (C) The following: - polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 8 to 15, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is a number ranging from 8 to 15, and M is an alkali metal cation or NH4 + and sulfonated or sulfated polyether derivatives of - Any combination of these At least one additive selected from and (D) optionally, an additional additive selected from animal glue, such as bone glue, lignosulfonates, aloin, and β-naphthol.

[0055] In a more preferred exemplary embodiment, the present invention comprises: (A) methanesulfonic acid, (B) lead methanesulfonate; (C) The following: polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is 10, 11, 12 or 13, Formula (IIa) (wherein Ar' is a 4-(C4-C 10 -alkyl)phenyl, o is 0, n' is 9, 10, 11 or 12, and M is an alkali metal cation or NH4 + or NH4 + Sulfonated or sulfated polyether derivatives of and - Any combination of these At least one additive selected from and (D) optionally, an additional additive selected from animal glue, such as bone glue, lignosulfonates, aloin, and β-naphthol.

[0056] In those exemplary embodiments, the components are included in electroplating baths according to the present invention at the respective concentrations typically or preferably set forth above for each component.

[0057] <Electrolytic refining process> In a second aspect, the present invention also provides a method for purifying a metal comprising electrolytically depositing a metal in an electroplating bath as described in the first aspect of the present invention. Any descriptions and preferences described above for electroplating baths are applicable here by reference.

[0058] The method for purifying metals according to the present invention can be carried out according to any known electroplating method without any particular restriction.

[0059] For example, a method for purifying a metal according to the present invention comprises the steps of: a) placing an anode made from the metal to be refined and a cathode in an electroplating bath; b) applying a voltage between the anode and the cathode for a time sufficient to deposit a layer of metal on the cathode.

[0060] The metal to be refined, ie, crude metal, may have a purity of at least 85%, for example 90-98.5%.

[0061] There are no particular limitations on the material of the cathode. Cathodes useful for electrolytic deposition can be made, for example, from stainless steel, titanium, or the same high purity metal as the metal to be refined. For example, the cathode can be made from high purity lead, where crude lead is refined by the method according to the invention.

[0062] Electrolytic deposition can be carried out at ambient or elevated temperatures, for example in the range of 20°C to 70°C, preferably 30°C to 60°C.

[0063] Useful current densities for electrolytic deposition are between 80 and 500 A / m 2 , preferably 100 to 300 A / m 2 , more preferably 140 to 260 A / m 2 The range may be:

[0064] The electroplating bath can be pumped at a flow rate of 40 to 80 liters per minute (L / min) during process operation. The electroplating bath can be pumped from the top into the electrolyte tank from a reservoir and exit at the bottom of the tank, or it can be pumped from the bottom into the electrolyte tank and exit at the top of the tank.

[0065] The anode and cathode can be placed at a distance of 1 cm to 10 cm, preferably 3 cm to 6 cm, for example 3 cm to 5.5 cm or 3 cm to 5 cm.

[0066] Electrolytic deposition may typically be carried out for 2 to 7 days, such as 3, 4, 5, 6, 7 days or even longer.

[0067] When the method for refining metals is carried out on a commercial scale, it is possible to envisage using multiple electroplating cells, which may be electrically connected in parallel.

[0068] By using the electroplating bath according to the present invention, a high current efficiency of 98% or more is obtained and a low bath voltage of 0.4 V or less is required, thus resulting in low energy consumption.

[0069] In a third aspect, the present invention further provides a method for controlling the morphology of a metal, particularly lead, deposited on a cathode in the electrorefining of a metal comprising using an electroplating bath as described in the first aspect of the present invention. Any descriptions and preferences described above for the electroplating bath are applicable here by reference.

[0070] The method for controlling the morphology of metals according to the present invention can be carried out under the conditions described in the second aspect of the present invention. Any descriptions and preferences described above for the electrorefining process are applicable here by reference.

[0071] In a fourth aspect, the present invention provides the use of the polyether derivatives, sulfonated or sulfated polyether derivatives, or any combination thereof, described herein in an electroplating bath for purifying a metal. EXAMPLES

[0072] Description of measurements in the examples: Scanning Electron Microscopy (SEM): A TESCAN MIRA3 LMU scanning electron microscope was used to characterize the appearance and morphology of the cathode deposits.

[0073] The current efficiency (η) was calculated according to the following formula:

number

[0074] Electrical energy consumption (W) was calculated according to the following formula:

number

[0075] Comparative Example 1: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to result in a solution containing 110 g / L of lead ions and 70 g / L of free methanesulfonic acid as the electroplating bath. The solution, maintained at 45°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 55 L / min. A pre-polished crude lead plate with a composition of 95.3% Pb, 0.04% Cu, 0.04% As, 1.01% Sb, 0.03% Sn, 0.02% Bi and 0.56% Ag with the remaining impurities was used as the anode and a pre-polished lead starting sheet was used as the cathode, which were placed at a distance of 5 cm. The current was 180 A / m 2Electroplating was carried out at 45° C. by applying a direct current with a current density of 1000000000 for a period of 2 hours.

[0076] The deposited lead was observed to have a rough surface, poor metallic luster and dendrites along the edges of the lead deposit, as shown in Figure 1. The bath voltage is 0.37 V, the current efficiency (η) is 97.4%, and the electrical energy consumption (W) is 95.4 kw·h / tPb, as measured by a Longway power supply LW-305KDS.

[0077] Comparative Example 2: The process was carried out in the same manner as Comparative Example 1, except that 1 g / L bone glue (available from WoLong Chemicals, China) was added as an additive to the electroplating bath, and electroplating was carried out for 3 days.

[0078] As shown in Figures 2A and 2B (enlarged view), it was observed that the deposited lead had surface pores but no substantial dendrites. The bath voltage was 0.35 V, the current efficiency was only 82.6%, and the electrical energy consumption was 107.9 kw·h / tPb.

[0079] Comparative Example 3: The process was carried out in the same manner as Comparative Example 1, except that 1 g / L calcium lignosulfonate (available from Shanghai Aladdin Bio-Chem Technology Co., Ltd., China) was added into the electroplating bath as an additive.

[0080] It was observed that the deposited lead had a rough surface, as shown in Figure 3. The bath voltage was 0.41 V, the current efficiency was 97.9%, and the electrical energy consumption was 110.4 kw·h / tPb.

[0081] Comparative Example 4: The process was carried out in the same manner as Comparative Example 1, except that 0.2 g / L bone glue and 2 g / L calcium lignosulfonate were added to the electroplating bath as additives.

[0082] It was observed that the deposited lead had poor metallic luster, as shown in Figure 4. The bath voltage was 0.47 V, the current efficiency was 99.2%, and the electrical energy consumption was 127.8 kw·h / tPb.

[0083] Comparative Example 5: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 100 g / L lead ions and 60 g / L free methanesulfonic acid as the electroplating bath, to which 0.3 g / L β-naphthol was added as an additive. The solution, maintained at 45°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 55 L / min. A pre-polished crude lead plate with a composition of 95.3% Pb, 0.04% Cu, 0.04% As, 1.01% Sb, 0.03% Sn, 0.02% Bi, 0.56% Ag and the remaining impurities was used as the anode and a pre-polished starting lead sheet was used as the cathode, both positioned at 4 cm. The electroplating current was 180 A / m 2 Electroplating was carried out at 45° C. by applying a direct current with a current density of 0.15 to 0.5 μm for a period of 8 hours.

[0084] As shown in Figures 5A and 5B (enlarged portion), it was observed that the deposited lead had a rough surface and poor metallic luster. The bath voltage was 0.37 V, the current efficiency (η) was 97.6%, and the electrical energy consumption (W) was 97.9 kw·h / tPb.

[0085] Example 1: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 100 g / L lead ions and 80 g / L free methylsulfonic acid as the electroplating bath, to which 2 g / L β-naphthol ethoxylate (12EO) and 0.5 g / L calcium lignosulfonate were added as additives. The solution, maintained at 50°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 40 L / min. A pre-polished crude lead plate with a composition of 96% Pb, 0.06% Cu, 0.05% As, 1.09% Sb, 0.01% Sn, 0.08% Bi, 0.54% Ag and the remaining impurities was used as the anode and a pre-polished titanium plate was used as the cathode, which were placed at a distance of 5 cm. The current was 190 A / m 2 Electroplating was carried out at 50°C by applying a direct current with a current density of 0.01 to 0.01 for 3 days.

[0086] As shown in Figures 6A and 6B (enlarged portion), the deposited lead was observed to have a smooth and dense surface along the edges of the lead deposit, and no dendrites or burrs. The bath voltage was 0.41 V, the current efficiency was 99.9%, and the electrical energy consumption was 106.4 kw·h / tPb.

[0087] Example 2: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 100 g / L lead ions and 80 g / L free methanesulfonic acid as the electroplating bath, to which 0.5 g / L β-naphthol ethoxylate (12EO) [commercially available from BASF] and 3 g / L sulfonate-substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) [commercially available from BASF] were added as additives. The solution, maintained at 40°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 50 L / min. A pre-polished crude lead plate with a composition of 94.5% Pb, 0.05% Cu, 0.80% As, 1.09% Sb, 0.01% Sn, 0.1% Bi, 0.45% Ag and the remaining impurities was used as the anode and a pre-polished lead starting sheet was used as the cathode, positioned at a distance of 4 cm. 180A / m 2Electroplating was carried out at 40° C. for 3 days by applying a direct current with a current density of 10 ...

[0088] As shown in Figures 7A and 7B (enlarged portion), the deposited lead was observed to have a smooth and dense surface along the edges of the lead deposit, and no dendrites or burrs. The bath voltage was 0.31 V, the current efficiency was 98.2%, and the electrical energy consumption was 81.6 kw·h / tPb.

[0089] Example 3: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 110 g / L lead ions and 60 g / L free methanesulfonic acid as the electroplating bath, to which 0.8 g / L calcium lignosulfonate and 0.5 g / L sulfonate-substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) [commercially available from BASF] were added as additives. The solution, maintained at 35°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 60 L / min. A pre-polished crude lead plate with a composition of 98.2% Pb, 0.02% Cu, 0.02% As, 0.3% Sb, 0.03% Sn, 0.01% Bi, 0.34% Ag and remaining impurities was used as the anode and a pre-polished lead starting sheet was used as the cathode, which were placed at a distance of 4.5 cm. 230 A / m 2 Electroplating was carried out at 35°C by applying a direct current with a current density of 0.01 to 0.01 for 3 days.

[0090] As shown in Figures 8A and 8B (enlarged portion), the deposited lead was observed to have a smooth and dense surface along the edges of the lead deposit, and no dendrites or burrs. The bath voltage was 0.40 V, the current efficiency was 98.5%, and the electrical energy consumption was 104.9 kw·h / tPb.

[0091] Example 4: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 120 g / L of lead ions and 100 g / L of free methanesulfonic acid as the electroplating bath, to which 0.5 g / L of calcium lignosulfonate, 1 g / L of sulfonate-substituted p-nonylphenol ethoxylate sulfate (10EO, sodium salt) [commercially available from BASF], and 1 g / L of β-naphthol ethoxylate (12EO) [commercially available from BASF] were added as additives. The solution, maintained at 40° C., was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 60 L / min. A pre-polished crude lead plate with the composition 97.5% Pb, 0.04% Cu, 0.04% As, 0.5% Sb, 0.03% Sn, 0.02% Bi, 0.31% Ag and the remaining impurities was used as the anode and a pre-polished lead starting sheet was used as the cathode, which were placed at a distance of 5 cm. 2 Electroplating was carried out at 40° C. for 3 days by applying a direct current with a current density of 10 ...

[0092] As shown in Figures 9A and 9B (enlarged portion), the deposited lead was observed to have a smooth and dense surface along the edges of the lead deposit, and no dendrites or burrs. The bath voltage was 0.09 V, the current efficiency was 98.8%, and the electrical energy consumption was 76.05 kw·h / tPb.

[0093] Example 5: Yellow PbO was dissolved in an aqueous solution of dilute methanesulfonic acid to provide a solution containing 110 g / L of lead ions and 70 g / L of free methanesulfonic acid as the electroplating bath, to which 0.5 g / L of calcium lignosulfonate and 1 g / L of β-naphthol ethoxylate (12EO) [commercially available from BASF] were added as additives. The solution, maintained at 45°C, was pumped from the bottom into the electrolyte tank and exited from the top at a flow rate of 55 L / min. A pre-polished crude lead plate with a composition of 95.3% Pb, 0.04% Cu, 0.04% As, 1.01% Sb, 0.03% Sn, 0.02% Bi, and 0.56% Ag was used as the anode and a pre-polished lead starting sheet was used as the cathode, which were placed at a distance of 5 cm. The current was 180 A / m 2 Electroplating was carried out at 45°C by applying a direct current with a current density of 0.01 to 0.01 for 3 days.

[0094] As shown in Figures 10A and 10B (enlarged portion), the deposited lead was observed to have a smooth and dense surface along the edges of the lead deposit, and no dendrites or burrs. The bath voltage was 0.35 V, the current efficiency was 98.8%, and the energy consumption was 94.7 kw·h / tPb.

Claims

1. (A) an alkane sulfonic acid or an alkanol sulfonic acid, (B) a soluble metal salt of an alkane sulfonic acid or an alkanol sulfonic acid; (C) The following: - Formula (I) 【Chemistry 1】 (In the formula, Ar is C ３ ~C １２ -phenyl substituted by alkyl, or Unsubstituted or C １ ~C ４ -naphthyl substituted by alkyl, E １ and E ２ are different from each other and are selected from ethyleneoxy and propyleneoxy, m is 0 or a number ranging from 1 to 40, preferably 0; n is a number ranging from 1 to 40; - Formula (II) 【Chemistry 2】 (In the formula, Ar' is C ３ ~C １２ -alkyl substituted and optionally -SO ３ phenyl substituted by a group of M, or Unsubstituted or C １ ~C ４ -Alkyl and / or -SO ３ naphthyl substituted by a group M; E １ ' and E ２ ' are different alkyleneoxy groups selected from ethyleneoxy and propyleneoxy; E ３ Is, E ２ is the alkylene portion of m' is 0 or a number ranging from 1 to 40, preferably 0; o is 0 or 1; the sum of n′+o is a number in the range of 1 to 40; and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and - any combination thereof and at least one additive selected from the group consisting of:

2. 2. The electroplating bath according to claim 1, wherein, in formula (I), m is 0 or a number in the range of 2 to 35, and, in formula (II), m' is 0 or a number in the range of 2 to 35, o is 0 or 1, and n'+o is a number in the range of 2 to 35.

3. The at least one additive (C) - Formula (I) (wherein, Ar is C ３ ~C １２ - alkyl, preferably C ４ ~C １０ -phenyl substituted by alkyl, or Unsubstituted or C １ ~C ４ -naphthyl substituted by alkyl, E １ and E ２ are different from each other and are selected from ethyleneoxy and propyleneoxy, m is 0 or a number ranging from 4 to 30; n is a number ranging from 4 to 30; - Formula (II) (wherein, Ar' is C ３ ~C １２ -alkyl substituted and optionally -SO ３ phenyl substituted by a group of M, or Unsubstituted or C １ ~C ４ -Alkyl and / or -SO ３ naphthyl substituted by a group M; E １ ' and E ２ ' are different alkyleneoxy groups selected from ethyleneoxy and propyleneoxy; E ３ Is, E ２ is the alkylene portion of m' is 0 or a number ranging from 4 to 30; o is 0 or 1; the sum of n′+o is a number in the range of 4 to 30; and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and - any combination thereof 3. The electroplating bath of claim 2, wherein the electroplating bath is selected from:

4. 2. The electroplating bath of claim 1, wherein the at least one additive (C) is selected from a polyether derivative of formula (I) where m is 0 and n is a number in the range of 4 to 30, preferably 6 to 20, more preferably 8 to 15, a sulfonated or sulfated polyether derivative of formula (II) where m' is 0, o is 0 or 1, and the sum of n'+o is a number in the range of 4 to 30, preferably 6 to 20, more preferably 8 to 15, or any combination thereof.

5. E ２ and E ２ 2. The electroplating bath of claim 1, wherein ' is ethyleneoxy.

6. The at least one additive (C) - Formula (Ia) 【Chemistry 3】 (In the formula, Ar is 4-(C ３ ~C １２ -alkyl)phenyl or unsubstituted naphthyl; n is a number ranging from 4 to 30; - Formula (II) 【Chemistry 4】 (In the formula, Ar' is optionally -SO ３ 4-(C ３ ~C １２ -alkyl)phenyl, or Unsubstituted or -SO ３ naphthyl substituted by a group M; o is 0 or 1; the sum of n′+o is a number in the range of 4 to 30; and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and - any combination thereof 4. The electroplating bath of claim 3, wherein the electroplating bath is selected from the group consisting of:

7. Ar is C ４ ~C １０ -alkyl substituted phenyl, preferably 4-(C ４ ~C １０ 2. The electroplating bath of claim 1, wherein the alkyl group is phenyl, phenyl, phenyl or unsubstituted naphthyl, preferably unsubstituted β-naphthyl.

8. 8. The electroplating bath of claim 7, wherein Ar is unsubstituted β-naphthyl.

9. Ar' is C ４ ~C １０ -Alkyl and -SO ３ Phenyl substituted by M, preferably -SO on the ring ３ 4-(C ４ ~C １０ -alkyl)phenyl, or unsubstituted or -SO ３ 2. The electroplating bath of claim 1 , wherein M is a substituted naphthyl.

10. Ar' is -SO at the 2- or 3-position of the phenyl ring. ３ 4-(C ４ ~C １０ 10. The electroplating bath of claim 9, wherein the alkyl group is aryl, aryl or aryl.

11. The at least one additive (C) polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 6 to 20, Formula (IIa) (wherein Ar′ is —SO 2 or 3 at the phenyl ring) ３ 4-(C ４ ~C １０ -alkyl)phenyl, o is 0, n' is a number ranging from 6 to 20, and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and 2. The electroplating bath of claim 1 selected from any combination thereof.

12. The at least one additive (C) polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is a number ranging from 8 to 15, Formula (IIa) (wherein Ar′ is —SO 2 or 3 at the phenyl ring) ３ 4-(C ４ ~C １０ -alkyl)phenyl, o is 0, n' is a number ranging from 8 to 15, and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and - any combination thereof 12. The electroplating bath of claim 11, wherein the electroplating bath is selected from the group consisting of:

13. The at least one additive (C) polyether derivatives of formula (Ia) in which Ar is unsubstituted β-naphthyl and n is 10, 11, 12 or 13, Formula (IIa) (wherein Ar′ is —SO 2 or 3 at the phenyl ring) ３ 4-(C ４ ~C １０ -alkyl)phenyl, o is 0, n' is 9, 10, 11 or 12, and M is an alkali metal cation or NH ４ ＋ Sulfonated or sulfated polyether derivatives of and - any combination thereof.

14. M is Na ＋ Or K ＋ 2. The electroplating bath of claim 1, wherein

15. The alkanesulfonic acid (A) is １ ~C １２ - Alkanesulfonic acids, preferably C １ ~C ６ 2. The electroplating bath according to claim 1, wherein the base is selected from the group consisting of alkanesulfonic acids, in particular methanesulfonic acid.

16. The alkanol sulfonic acid (A) is ２ ~C １２ -Alkanolsulfonic acids, preferably C ２ ~C ６ 2. The electroplating bath according to claim 1, wherein the base is selected from the group consisting of aryl, aryl- ...

17. 2. The electroplating bath of claim 1, wherein the soluble metal salt (B) is at least one soluble metal salt of the same alkane sulfonic acid or alkanol sulfonic acid as component (A).

18. 2. The electroplating bath according to claim 1, wherein the metal of the soluble metal salt (B) is selected from lead and tin, in particular lead.

19. 2. The electroplating bath of claim 1, wherein the at least one additive is each included in the electroplating bath at a concentration in the range of 0.5 to 5.0 g / L of bath, in particular 0.5 to 3.0 g / L.

20. 2. The electroplating bath according to claim 1, comprising as component (C) a combination of at least one polyether derivative and at least one sulfonated or sulfated polyether derivative, preferably in a total concentration in the range of 1.0 to 5.0 g / L of the bath, in particular 2.0 to 5.0 g / L.

21. 2. The electroplating bath according to claim 1, comprising an additional additive (D) selected from animal glue, such as bone glue, lignosulfonates, aloin and β-naphthol, in particular lignosulfonates.

22. 22. The electroplating bath of claim 21 comprising the additional additive in a concentration ranging from 0.1 to 2.0 g / L of bath.

23. A method for purifying a metal comprising electrolytically depositing a metal in the electroplating bath of any one of claims 1 to 22.

24. a) placing an anode made from the metal to be refined and a cathode in the electroplating bath; 24. The method of claim 23, comprising: b) applying a voltage between the anode and the cathode for a time sufficient to deposit a layer of the metal on the cathode.

25. 24. The method according to claim 23, wherein the metal is selected from lead and tin, in particular lead.

26. A method for controlling the morphology of metal, in particular lead, deposited on a cathode in the electrorefining of metals, comprising using an electroplating bath according to any one of claims 1 to 22.

27. Use of the polyether derivatives of formula (I), the sulfonated or sulfated polyether derivatives of formula (II) or any combination thereof according to any one of claims 1 to 13 in an electroplating bath for purifying metals.

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