Titanium cathode plate treatment method

Abstract

The invention belongs to the technical field of electrodeposited cobalt and electrodeposited nickel, and particularly relates to a titanium cathode plate treatment method which comprises the following steps: S1, obtaining a titanium cathode plate to be treated, and pretreating the titanium cathode plate; s2, scalding the titanium negative plate for the first time; s3, scalding the titanium negative plate for the second time; s4, the titanium negative plate is used for preparing a starting sheet; according to the method, the titanium cathode plate is scalded by adopting two-stage gradient temperature, so that a nanometer oxidation film is generated on the surface of the titanium cathode plate, the interface energy is reduced, the stripping power is reduced, the starting sheet is easy to strip, and the stripping efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of electrowinning cobalt and nickel technology, specifically a method for processing titanium cathode plates. Background Technology

[0002] Currently, the cobalt (nickel) electrowinning industry primarily uses starter sheets as cathode plates for electrowinning cobalt (nickel) products. Due to the high stress in cobalt electrowinning, the starter sheets in the seed plate cell are prone to detaching from the titanium cathode plate, causing them to burst. The starter sheets are thin, easily deformed, and some surfaces turn black. Bursted starter sheets cannot be used for starter sheet processing, reducing the yield of finished starter sheets. To reduce the occurrence of bursting, the titanium cathode plates need to be pre-treated periodically. However, after pre-treatment, the titanium seed plates are often difficult to peel off during electrowinning, affecting the efficiency of the stripping unit. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a method for processing a titanium cathode plate, comprising the following steps: S1, obtaining a titanium cathode plate to be processed and pre-processing the titanium cathode plate; S2, performing a first hot wash on the titanium cathode plate; S3, performing a second hot wash on the titanium cathode plate; S4, using the titanium cathode plate for the preparation of a starter sheet.

[0004] In a preferred embodiment of the titanium cathode plate processing method of the present invention, in step S2, the temperature of the first scalding is 80-85°C and the time is 10-20 minutes, and deionized water is used for the first scalding. Furthermore, the temperature of the first scalding wash is any one of 80℃, 81℃, 82℃, 83℃, 84℃, or 85℃, or a range between two of them.

[0005] In a preferred embodiment of the titanium cathode plate processing method of the present invention, in step S3, the temperature of the second scalding is 60-65°C and the time is 20-40 minutes, and deionized water is used for the second scalding.

[0006] Furthermore, the temperature of the second scalding wash is any one of 60℃, 61℃, 62℃, 63℃, 64℃, and 65℃, or a range between two of them.

[0007] As a preferred embodiment of the processing method of the titanium cathode plate of the present invention, the pretreatment in step S1 includes: S11, peeling off the starting electrode sheet on the titanium cathode plate and rinsing it with deionized water for 30-60 minutes.

[0008] As a preferred embodiment of the processing method of the titanium cathode plate of the present invention, the method further includes the following steps after step S11: S12, polishing the titanium cathode plate after grinding, wherein the polishing is performed by a polishing machine at a speed of 800-1500 rpm.

[0009] As a preferred embodiment of the processing method of the titanium cathode plate of the present invention, the method further includes the following step after step S12: S13, acid washing the titanium cathode plate with an acid solution for 2-4 hours.

[0010] In a preferred embodiment of the processing method for a titanium cathode plate according to the present invention, the acid solution is hydrochloric acid or sulfuric acid.

[0011] In a preferred embodiment of the method for processing a titanium cathode plate according to the present invention, the concentration of hydrogen ions in the acid solution is 1-4 mol / L. Furthermore, the concentration of hydrogen ions in the acid solution is any one of 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, or a range between two of them.

[0012] As a preferred embodiment of the processing method of the titanium cathode plate of the present invention, step S4 further includes: applying the titanium cathode plate to the preparation of the starting electrode for no more than 72 hours.

[0013] As a preferred embodiment of the processing method of the titanium cathode plate of the present invention, step S4 further includes: peeling off the starting sheet, wherein the yield of the starting sheet is ≥90%.

[0014] This invention employs a two-stage gradient temperature to heat-wash the titanium cathode plate, thereby generating a nano-sized oxide film on its surface. This reduces the interfacial energy and peeling work, making the initial electrode easier to peel off and improving peeling efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 The images show the XRD patterns of the titanium cathode plate processing at each stage in Example 1.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A method for processing a titanium cathode plate includes the following steps: S1. Obtain the titanium cathode plate to be processed and pre-process the titanium cathode plate; The titanium cathode plate to be processed in this invention is a titanium cathode plate that has been used continuously for 15-20 days in the process of electrowinning cobalt or nickel, and can be a titanium cathode plate used for the preparation of the starter sheet.

[0020] The pretreatment steps for titanium cathode plates mainly include: removing residual cobalt or nickel from the titanium cathode plate, then soaking the titanium cathode plate in deionized water for 30-60 minutes to remove residual acid from the surface of the titanium cathode plate; grinding the titanium cathode plate with an angle grinder or belt sander, first grinding off the incompletely removed cobalt or nickel from the titanium cathode plate, then grinding evenly along the grain direction of the titanium cathode plate, and finally polishing with a polishing machine at a speed of 800-1500 rpm.

[0021] The pretreatment steps for titanium cathode plates also include: acid washing of the titanium cathode plates. If a sulfuric acid system is used when electrodepositing cobalt or nickel using titanium cathode plates, then dilute sulfuric acid should be used for acid washing. If a hydrochloric acid system is used when electrodepositing cobalt or nickel using titanium cathode plates, then dilute hydrochloric acid should be used for acid washing. During the acid washing process using hydrochloric acid or sulfuric acid, the concentration of hydrogen ions in the acid solution is 1-4 mol / L, and the acid washing time is 2-4 hours.

[0022] S2. Perform a first hot wash on the titanium cathode plate; The specific steps of the first hot-washing of the titanium cathode plate in this invention include: hot-washing with deionized water at a temperature of 80-85℃ for 10-20 minutes; the first hot-washing removes residual sulfuric acid and acid pickling byproducts (TiOSO4 or TiOCl2), and repairs the oxide film generated by acid pickling, which may have microscopic defects (such as cracks or sulfur adsorption), through a high-temperature water environment. In the high-temperature water environment (80-85℃), the amorphous regions or defects on the TiO2 surface will locally dissolve, and subsequently, under thermodynamic drive, the dissolved Ti... 4+ and OH - Redeposited to the defect location: TiO2 (defect) + 2H2O Ti 4+ +4OH -→TiO2 (complete).

[0023] S3. Perform a second hot water wash on the titanium cathode plate; The second hot washing step of the titanium cathode plate in this invention specifically includes: hot washing with deionized water at a temperature of 60-65°C for 20-40 minutes; the second hot washing causes the titanium oxide film to transform from an amorphous state to a crystalline state, making the oxide film structure denser and reducing the interfacial energy, making the initial electrode sheet easier to peel off after the titanium cathode plate is prepared.

[0024] S4. Use the titanium cathode plate for the preparation of the starting electrode.

[0025] The titanium cathode plate processed by steps S1, S2, and S3 in this invention can be used to prepare cobalt or nickel starter sheets; furthermore, the time for applying the processed titanium cathode plate to the preparation of starter sheets shall not exceed 72 hours from the completion of the processing.

[0026] In this invention, when the treated titanium cathode plate is exposed to air for a long time, the TiO2 passivation film on the titanium surface will react further with O2 and H2O in the air, resulting in a slow thickening of the oxide film: Ti + O2 → TiO2 (at a rate of about 0.1-0.5 nm / day at room temperature); this will lead to an increase in electron tunneling resistance, an increase in electrodeposition overpotential, and an increase in crystallinity, which will reduce the self-healing ability of the oxide film.

[0027] Example 1 Titanium cathode plates that have been used continuously for 15 days were soaked in a deionized water bath for 50 minutes, then ground with an angle grinder and polished with a polishing machine at 1000 rpm. They were then acid-washed with 2 mol / L dilute sulfuric acid for 2 hours, and after standing for a period of time, transferred to a hot water bath. A first hot water bath was performed with deionized water at 85℃ for 10 minutes. A second hot water bath was then performed with deionized water at 60℃ for 30 minutes. After the hot water bath, the titanium cathode plates were used to prepare cobalt starting sheets, with a yield of 92% for the prepared starting sheets.

[0028] Example 2 Titanium cathode plates that had been used continuously for 17 days were soaked in a deionized water bath for 30 minutes, then ground with an angle grinder and polished with a polishing machine at 800 rpm. They were then acid-washed with 1.5 mol / L dilute sulfuric acid for 2 hours, and after standing for a period of time, transferred to a hot water bath. A first hot water bath was performed with deionized water at 80℃ for 15 minutes. A second hot water bath was performed with deionized water at 65℃ for 20 minutes. After the hot water bath, the titanium cathode plates were used to prepare cobalt starter sheets, with a yield of 93%.

[0029] Example 3 Titanium cathode plates that have been used continuously for 20 days were soaked in a deionized water bath for 60 minutes, then ground with an angle grinder and polished with a polishing machine at 1500 rpm. They were then acid-washed with 0.5 mol / L dilute sulfuric acid for 2 hours, and after standing for a period of time, transferred to a hot water bath. A first hot water bath was performed with deionized water at 83℃ for 20 minutes. A second hot water bath was performed with deionized water at 63℃ for 40 minutes. After the hot water bath, the titanium cathode plates were used to prepare cobalt starter sheets, with a yield of 94%.

[0030] Comparative Example 1 Titanium cathode plates that had been used continuously for 15 days were soaked in a deionized water bath for 30 minutes, then ground with an angle grinder and polished with a polishing machine at 800 rpm. They were then acid-washed with 1.5 mol / L dilute sulfuric acid for 2 hours, and after standing for a period, transferred to a hot water bath. A first hot water bath was performed with deionized water at 80℃ for 15 minutes. A second hot water bath was performed with deionized water at 65℃ for 20 minutes. Five days after the hot water bath was completed, the titanium cathode plates were used to prepare cobalt starter sheets. The yield of the prepared starter sheets was 84%.

[0031] Comparative Example 2 Titanium cathode plates that have been used continuously for 15 days were soaked in a deionized water bath for 20 minutes, then ground with an angle grinder and polished with a polishing machine at 500 rpm. They were then acid-washed with 0.3 mol / L dilute sulfuric acid for 1 hour, and after standing for a period of time, transferred to a hot water bath. A first hot water bath was performed with deionized water at 70℃ for 8 minutes. A second hot water bath was performed with deionized water at 55℃ for 15 minutes. After the hot water bath, the titanium cathode plates were used to prepare cobalt starter sheets, with a yield of 70%.

[0032] Comparative Example 3 Titanium cathode plates that had been used continuously for 15 days were soaked in a deionized water bath for 70 minutes, then ground with an angle grinder and polished with a polishing machine at 1700 rpm. They were then acid-washed with 3 mol / L dilute sulfuric acid for 5 hours, and after standing for a period of time, transferred to a hot water bath. A first hot water bath was performed with deionized water at 90℃ for 30 minutes. A second hot water bath was then performed with deionized water at 70℃ for 50 minutes. After the hot water bath, the titanium cathode plates were used to prepare cobalt starting sheets. The yield of the prepared starting sheets was 74%.

[0033] Comparative Example 4 Titanium cathode plates that have been used continuously for 15 days were soaked in a deionized water bath for 30 minutes, then ground with an angle grinder and polished with a polishing machine at 800 rpm. They were then acid-washed with 1.5 mol / L dilute sulfuric acid for 2 hours, allowed to stand for a period, and then transferred to a hot water bath. Deionized water was used for hot water washing at 80℃ for 15 minutes. After hot water washing, the titanium cathode plates were used to prepare cobalt starter sheets, with a yield of 85% for the prepared starter sheets.

[0034] See also Figure 1 , Figure 1 The XRD patterns of the titanium cathode plate at each stage of the treatment in Example 1 are shown. The XRD peaks show that the titanium cathode plate after the second hot washing has obvious and sharp diffraction peaks, which are diffraction peaks of the titanium oxide film, indicating that the oxide film is crystalline. The titanium cathode plate after the first hot washing shows relatively wide and indistinct diffraction peaks (only one or a few broadened "humps" are detected) on the left side, which are amorphous oxide films. The titanium cathode plate after acid washing has no diffraction peaks of titanium oxide film on its surface.

[0035] The examples and comparative examples demonstrate that the present invention uses a technical solution of grinding, polishing, acid washing, and two-stage hot washing with gradient temperature to process titanium cathode plates. The titanium cathode plates processed using the technical solution of the present invention can significantly increase the yield of the starting electrode.

[0036] This invention employs a two-stage gradient temperature to heat-wash the titanium cathode plate, thereby generating a nano-sized oxide film on its surface. This reduces the interfacial energy and peeling work, making the initial electrode easier to peel off and improving peeling efficiency.

[0037] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for processing a titanium cathode plate, characterized in that, Includes the following steps: S1. Obtain the titanium cathode plate to be processed and pre-process the titanium cathode plate; S2. Perform a first hot wash on the titanium cathode plate; S3. Perform a second hot water wash on the titanium cathode plate; S4. Use the titanium cathode plate for the preparation of the starting electrode sheet; In step S2, the temperature of the first scalding wash is 80-85℃, the time is 10-20 minutes, and deionized water is used for the first scalding wash. In step S3, the temperature of the second scalding is 60-65℃, the time is 20-40 minutes, and deionized water is used for the second scalding.

2. The method for processing a titanium cathode plate according to claim 1, characterized in that, The preprocessing in step S1 includes: S11. Peel off the starting electrode sheet from the titanium cathode plate and soak it in deionized water for 30-60 minutes.

3. The method for processing a titanium cathode plate according to claim 2, characterized in that, The process following step S11 also includes: S12. After grinding the titanium cathode plate, polish it. The polishing is performed using a polishing machine at a speed of 800-1500 rpm.

4. The method for processing a titanium cathode plate according to claim 3, characterized in that, Following step S12, the following is also included: S13. The titanium cathode plate is acid-washed with an acid solution for 2-4 hours.

5. The method for processing a titanium cathode plate according to claim 4, characterized in that, The acid solution is hydrochloric acid or sulfuric acid.

6. The method for processing a titanium cathode plate according to claim 5, characterized in that, The concentration of hydrogen ions in the acid solution is 1-4 mol / L.

7. The method for processing a titanium cathode plate according to claim 1, characterized in that, Step S4 further includes: applying the titanium cathode plate to the preparation of the starting electrode for no more than 72 hours.

8. The method for processing a titanium cathode plate according to claim 1, characterized in that, Step S4 further includes: peeling off the starter sheet, wherein the yield of the starter sheet is ≥90%.

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