CN212335350U

CN212335350U - Device for regenerating noble metal electroplating solution by membrane electrolysis method

Info

Publication number: CN212335350U
Application number: CN202021001977.2U
Authority: CN
Inventors: 王芳; 王兴平; 王爱臣; 陈恒
Original assignee: Cookson Enthone Chemistry Shanghai Co Ltd
Current assignee: Alent Enthone Chemistry Shanghai Co Ltd
Priority date: 2020-06-03
Filing date: 2020-06-03
Publication date: 2021-01-12
Anticipated expiration: 2030-06-03

Abstract

The utility model discloses a device of noble metal plating solution is regenerated to membrane electrolysis method, the device includes: the device comprises an anode pool, a cathode pool, an intermediate pool positioned between the anode pool and the cathode pool, an anion exchange membrane separating the anode pool from the intermediate pool, a proton exchange membrane separating the intermediate pool from the cathode pool, a power supply for supplying power, an anode electrode placed in the anode pool and a cathode electrode placed in the cathode pool, wherein the power supply is connected with the anode electrode and the cathode electrode through leads and supplies power to the two electrodes, the anode pool and the cathode pool are used for containing electrolyte, and the intermediate pool is used for containing precious metal electroplating solution to be regenerated. The utility model discloses a device passes through the by-product acid in the membrane electrolysis method detach noble metal plating solution, does not introduce other impurity to under the original complex system of assurance plating solution is not destroyed the condition, the noble metal plating solution of regeneration.

Description

Device for regenerating noble metal electroplating solution by membrane electrolysis method

Technical Field

The utility model relates to a device for regenerating electroplating solution, in particular to a device for regenerating noble metal plating solution by membrane electrolysis.

Background

Insoluble anodes are commonly used in noble metal plating, and during the plating process, the anodic reaction typically produces hydrogen ions, which cause the pH of the plating solution to decrease. In addition, the water electrolyzed at the insoluble anode generates hydrogen ions, and the hydrogen ions react with anions in the noble metal plating solution to generate acid (for example, the hydrogen ions combine with sulfate radicals in a sulfate type platinum plating solution to generate acid, which causes the acid content in the plating solution to be higher and higher during the solution replenishment process, thereby affecting the plating efficiency and deteriorating the plating quality.

In industrial applications, precious metal plating solutions are typically scrapped after a period of use due to the high level of impurities. There have been attempts at plating plants to neutralize excess acid with a base and to remove salts produced during neutralization by precipitation methods. In the process, on one hand, the original complexing system is destroyed due to direct acid-base reaction, and on the other hand, new impurity ions are introduced, so that the effect is not ideal.

SUMMERY OF THE UTILITY MODEL

To the defect that exists among the prior art, to noble metal plating solution regeneration process, the utility model aims at providing a device of noble metal plating solution is regenerated to membrane electrolysis method, the device includes: an anode cell, a cathode cell, an intermediate cell positioned between the anode cell and the cathode cell, an anion exchange membrane separating the anode cell from the intermediate cell, a proton exchange membrane or a cation exchange membrane separating the intermediate cell from the cathode cell, a power source providing electrical power, an anode electrode positioned in the anode cell and a cathode electrode positioned in the cathode cell,

wherein the power supply is connected with the anode electrode and the cathode electrode through leads to supply power to the two electrodes, the anode pool and the cathode pool are used for containing electrolyte, and the middle pool is used for containing the noble metal electroplating solution to be regenerated.

Preferably, the power supply provides a dc power.

Preferably, the dc power supply has a dc current density of between 1 amp per square decimeter and 10 amps per square decimeter.

Preferably, the noble metal plating solution is a gold, silver, palladium, osmium, iridium, platinum, or palladium plating solution.

Preferably, the electrolyte has the same anion as the noble metal plating solution.

Preferably, the anode pool, the cathode pool and the intermediate pool are rectangular in cross section.

Preferably, the volume of the intermediate cell is greater than the volumes of the anode cell and the cathode cell.

Preferably, the anion exchange membrane is selected from a polyethylene homogeneous anion membrane, a polysulfone homogeneous anion membrane or a polyvinyl fluoride polyamine type anion membrane.

Preferably, the proton exchange membrane or cation exchange membrane is selected from polyethylene cation membranes or polyphenylene ether homogeneous membranes.

Preferably, the anode electrode is selected from a platinum electrode, a metal oxide electrode, a titanium electrode or a stainless steel electrode.

Preferably, the cathode electrode is selected from a platinum electrode, a metal oxide electrode, a titanium electrode or a stainless steel electrode.

Preferably, the anode pool, the cathode pool and the intermediate pool are made of non-metallic materials selected from polypropylene, polyethylene, polyvinyl chloride or ceramics.

After the device for regenerating noble metal electroplating solution by membrane electrolysis described in the utility model is electrified, the cathodeThe electrolyte in the cell undergoes a chemical reaction: h₂O+e^-→OH^-+H₂(ii) a The electrolyte in the anode cell undergoes a chemical reaction: h₂O-e^-→H⁺+O₂。

The diaphragm between the middle pool and the anode pool of the device for regenerating noble metal electroplating solution by membrane electrolysis is an anion exchange membrane which is a semipermeable membrane. Anions in the noble metal electroplating solution in the middle pool can move from the middle pool side to the anode pool side through the anion exchange membrane. The diaphragm between the middle pool and the cathode pool is a cation exchange membrane or a proton exchange membrane, and hydrogen ions or impurity cations in the noble metal electroplating solution in the middle pool can move from one side of the middle pool to one side of the cathode pool through the proton exchange membrane or the cation exchange membrane under the action of an electric field or concentration difference.

When the power is turned on, the electrolyte in the cathode cell undergoes a chemical reaction: h₂O+e^-→OH^-+H₂The electrolyte in the anode cell undergoes a chemical reaction: h₂O-e^-→H⁺+O₂Causing OH of the electrolyte in the cathode cell^-Increasing concentration of H of electrolyte in anode cell⁺The concentration is increased more and more, so that hydrogen ions or impurity cations in the precious metal electroplating solution in the middle pool are promoted to permeate through the proton exchange membrane or the cation exchange membrane to move to the cathode pool, and anions in the precious metal electroplating solution permeate through the anion exchange membrane to move to the anode pool. Meanwhile, under the action of an electric field formed by a direct current power supply, anions in the electroplating solution to be regenerated permeate through an anion exchange membrane to move towards an anode pool, and hydrogen ions or impurity cations permeate through a proton exchange membrane or a cation exchange membrane to move towards a cathode pool to move towards the cathode pool. Thus, under the action of the concentration difference and the electric field formed by the direct current power supply, the by-product acid and the impurity cations in the electroplating solution to be regenerated are enriched and removed in the cathode pool.

Through the technical scheme, the beneficial effects of the utility model are that:

the utility model discloses a device of membrane electrolysis method regeneration noble metal plating solution passes through the by-product acid in the membrane electrolysis method detached noble metal plating solution, does not introduce other impurity to under the original complex system of assurance noble metal plating solution was not destroyed, regeneration noble metal plating solution, and this regeneration noble metal plating solution can normal use.

Drawings

The following drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain and explain the invention:

FIG. 1 is a schematic view showing the structure of an apparatus for regenerating a noble metal plating solution by membrane electrolysis according to the present invention.

Detailed Description

In the description of the utility model, the shape and size of the anode pool, the middle pool and the cathode pool can be determined according to practical application. The materials of construction of these cells include, but are not limited to, non-metallic materials such as polypropylene, polyethylene, polyvinyl chloride, ceramics, and the like.

The utility model discloses an in the description, the type and the ionic radius of the ion that ion exchange membrane should select as required to see through select, should consider the intensity of membrane simultaneously, performances such as acid and alkali-resistance and resistant electrochemistry. When the ion exchange membrane is used, the ion exchange membrane is cleaned, swelled and the like according to the use instruction so as to ensure that the diaphragm does not pollute the plating solution.

In the description of the present invention, the anode electrode material placed in the anode pool includes, but is not limited to, platinum electrode, metal oxide electrode, titanium electrode, stainless steel electrode, etc. The anode electrode is selected in accordance with the electrolyte used in the anode cell, and preferably selected from an insoluble platinum titanium anode having a low overpotential and a noble metal oxide electrode.

In the description of the present invention, the cathode electrode material placed in the cathode cell includes, but is not limited to, cathode electrode selected from platinum electrode, metal oxide electrode, titanium electrode, stainless steel electrode, etc., and similarly, the cathode electrode is selected according to the electrolyte used in the cathode cell, preferably, the overpotential is low, insoluble platinum titanium anode, noble metal oxide electrode, etc.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

Referring to FIG. 1, there is shown an apparatus 1 for regenerating a noble metal plating solution by membrane electrolysis in an embodiment comprising: an anode cell 10, an intermediate cell 20, a cathode cell 30, an anion exchange membrane 40 separating the anode cell 10 from the intermediate cell 20, a proton exchange membrane (or cation exchange membrane) 50 separating the intermediate cell 20 from the cathode cell 30, an anode electrode 11, a cathode electrode 31, and a power supply 60 for supplying electric power. An anode electrode 11 is located in the anode cell 10 and a cathode electrode 31 is located in the cathode cell 30. The power supply 60 is connected to the anode electrode 11 and the cathode electrode 31 through wires to supply a direct current to both electrodes, wherein the positive electrode of the power supply 60 is directly connected to the anode electrode 11 and the negative electrode of the power supply 60 is directly connected to the cathode electrode 21.

The anode cell 10 and the cathode cell 30 are used for holding the electrolyte, and the intermediate cell 20 is used for holding the electrolyte of the noble metal to be regenerated.

In use, the anode cell 10 and the cathode cell 30 of the apparatus 1 for regenerating noble metal plating solution by membrane electrolysis shown in fig. 1 are respectively added with electrolyte, the noble metal plating solution to be regenerated is added into the intermediate cell 20, the direct current power supply 60 is switched on, and the electrolyte in the anode cell 10 reacts under the action of the anode electrode 11: h₂O-e^-→H⁺+O₂The electrolyte in the cathode cell 20 reacts under the action of the cathode electrode 21: h₂O+e^-→OH^-+H₂Causing OH of the electrolyte in the cathode cell 30^-The greater and greater the concentration of H of the electrolyte in the anode cell 10⁺The increasing concentration causes hydrogen ions or impurity cations in the noble metal plating solution in the intermediate tank 20 to move toward the cathode tank 30 through the proton exchange membrane (or cation exchange membrane) 50, and anions in the noble metal plating solution to move toward the anode tank 10 through the anion exchange membrane 40. Meanwhile, under the action of the electric field formed by the DC power supply, anions in the noble metal electroplating solution permeate the anion exchange membrane 40 to move to the anode tank 10, and hydrogen ions or impurity cations permeate the proton exchange membrane (or cation exchange membrane) 50 to move to the cathode tank 30. Thus, by-product acid and impurity cations in the noble metal plating solution to be regenerated are removed in the cathode pool 30 by concentration difference and direct current.

The apparatus should be cleaned of the three chambers prior to first use to prevent contamination of the plating solution by substances contained on the surface of the cell material. In addition, the ion exchange membrane should be cleaned before use according to the instructions. After the cleaning, electrolyte and aged electroplating solution should be added into the three electrolytic cells respectively, and the liquid level is kept close to avoid the damage to the ion exchange membrane caused by the overlarge pressure on one side. When the direct current power supply is turned on for electrolysis, the current is set according to the specification of the ion exchange membrane and should not exceed the maximum current density which can be borne by the ion exchange membrane. During the electrolysis, the concentration of the plating solution, in particular the acid concentration, in the intermediate cell should be monitored. When the acid concentration is reduced to a reasonable range, the electrolysis is stopped, so as to avoid electrolyzing the effective components in the electroplating solution. After the step of electrolytic deacidification is completed, the electroplating solution is further analyzed and adjusted, and relevant performance tests such as Hall cell plate tests, current efficiency tests and the like are carried out to ensure that the regenerated solution can meet the actual production requirements.

Example 2

Aged platinum plating solution (main component is H) using the apparatus shown in FIG. 1₂Pt(NO₂)₂SO₄) Regeneration is carried out. The aged platinum electroplating solution is placed in an intermediate tank 20, sulfuric acid aqueous solution with the mass concentration of 50% is placed in an anode tank 10 and a cathode tank 20, polyethylene system membrane materials are used for an anion exchange membrane 40 and a proton exchange membrane 50, and platinum is used for anode electrode materials and cathode electrode materials. The power supply was turned on, the energization current was set at 1 amp per hour, and the treatment time was 20 hours.

The electroplating solution is obtained by performing neutralization titration by using NaOH aqueous solution, the aged platinum electroplating solution before treatment contains 150 g/L of acid, and the solution after treatment contains 45 g/L of acid. Under the condition of relatively low acid content, the current efficiency of the solution is greatly improved, and the solution can be completely used as a normal platinum electroplating solution.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An apparatus for regenerating a noble metal plating solution by membrane electrolysis, comprising: an anode cell, a cathode cell, an intermediate cell positioned between the anode cell and the cathode cell, an anion exchange membrane separating the anode cell from the intermediate cell, a proton exchange membrane or a cation exchange membrane separating the intermediate cell from the cathode cell, a power source providing electrical power, an anode electrode positioned in the anode cell and a cathode electrode positioned in the cathode cell,

2. The apparatus of claim 1, wherein the power source provides a direct current power source.

3. The apparatus of claim 1, wherein the noble metal plating solution is a gold, silver, palladium, osmium, iridium, platinum, or palladium plating solution.

4. The apparatus of claim 1, wherein the electrolyte has the same anion as the noble metal plating solution.

5. The apparatus of claim 1, wherein the anode cell, the cathode cell, and the intermediate cell are all rectangular in cross-section.

6. The apparatus of claim 1, wherein the volume of the intermediate cell is greater than the volume of the anode cell and the cathode cell.

7. The device according to claim 1, wherein the anion exchange membrane is selected from a polyethylene homogeneous anion membrane, a polysulfone homogeneous anion membrane or a polyvinyl fluoride polyamine type anion membrane.

8. The device according to claim 1, wherein the proton exchange membrane or cation exchange membrane is selected from polyethylene cation membranes or polyphenylene ether homogeneous membranes.

9. The device of claim 1, wherein the anode electrode is selected from a platinum electrode, a metal oxide electrode, a titanium electrode, or a stainless steel electrode.

10. The device of claim 1, wherein the cathode electrode is selected from a platinum electrode, a metal oxide electrode, a titanium electrode, or a stainless steel electrode.