Anode plate for manganese electrolysis process and preparation method of anode plate

Abstract

The invention relates to the field of electrolytic materials containing rare earth or plasma spraying, in particular to an anode plate for a manganese electrolysis process and a preparation method of the anode plate. The rare earth La is doped into the plasma spraying TiN coating, so that the corrosion resistance of the plasma spraying TiN coating can be remarkably improved, the corrosion resistance of the composite coating is gradually improved along with the increase of the rare earth content, and the increase trend tends to be gentle. Meanwhile, the hardness of the composite coating is in a trend of increasing firstly and then reducing, so that the mass content of the rare earth La needs to be controlled at 4.3-10.7% in practice.

Description

Technical Field

[0001] This invention relates to the field of electrolytic materials or plasma spraying containing rare earth elements, and specifically to an anode plate for electrolytic manganese processes and its preparation method. Background Technology

[0002] In the smelting of metallic manganese, over 90% of the manganese is extracted using hydrometallurgical techniques. Among these techniques, the anode plate is one of the most crucial factors affecting the energy consumption, efficiency, and quality of manganese electrowinning. Existing technology (using Ti / TiN for electrolytic manganese) x Preparation and Application Research of Mn2O3 Anodes (Chen Xiangjia) (Ti / TiN) x Mn2O3 anodes can solve problems such as high energy consumption and low manganese ion utilization in traditional processes. However, TiN x Its poor resistance to electrochemical corrosion severely affects the oxygen evolution capacity and service life of the electrode. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing an anode plate for electrolytic manganese processes, which can obtain an anode plate material with excellent hardness and corrosion resistance.

[0004] The technical solution of the present invention is as follows: A method for preparing an anode plate for electrolytic manganese processes includes the following steps: Substrate pretreatment: Select titanium plate as substrate material and cut it into appropriate size. Then, put the substrate into 10-12wt% hydrochloric acid solution for acid washing, then put it into 5-6wt% sodium hydroxide solution for alkaline washing, and finally wash it with deionized water and dry it for use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 4.3-10.7%. During the plasma spraying process, the working current is 500-520A, the working voltage is 80-85V, the argon pressure is 0.5-0.6MPa, the hydrogen pressure is 0.2-0.5MPa, the powder feeding speed is 3.5-3.8g / min, and the spraying distance is 100-120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4-4.5 hours at a temperature of 400-450℃.

[0005] Preferably, the operating current is 500A.

[0006] Preferably, the operating voltage is 80V.

[0007] Preferably, the powder feeding speed is 3.5 g / min.

[0008] Preferably, the spraying distance is 100mm.

[0009] Preferably, the argon gas pressure is 0.5 MPa.

[0010] Preferably, the hydrogen pressure is 0.2 MPa.

[0011] Furthermore, the present invention also provides an anode plate for electrolytic manganese processes, wherein the anode plate is prepared by the above-described method.

[0012] The present invention demonstrates that incorporating rare earth element La into plasma-sprayed TiN coatings can significantly improve their corrosion resistance. As the rare earth content increases, the corrosion resistance of the composite coating gradually increases, and this increasing trend tends to level off. Simultaneously, the hardness of the composite coating exhibits a trend of first increasing and then decreasing. Therefore, in practice, the mass content of rare earth element La needs to be controlled between 4.3% and 10.7%. Detailed Implementation

[0013] The technical effects of the present invention will be verified through specific embodiments below, but the implementation of the present invention is not limited thereto.

[0014] Example 1 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 4.3%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0015] Example 2 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 5.8%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0016] Example 3 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 7.2%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0017] Example 4 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 8.9%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0018] Example 5 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 10.7%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0019] Comparative Example 1 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN layer: TiN powder is used as raw material to prepare a TiN layer on the substrate surface by plasma spraying. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0020] Comparative Example 2 Substrate pretreatment: Titanium plate is selected as the substrate material and cut into appropriate sizes. Then, the substrate is placed in a 10wt% hydrochloric acid solution for acid washing, then placed in a 5wt% sodium hydroxide solution for alkaline washing, and finally rinsed with deionized water and dried for later use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 15%. During the plasma spraying process, the working current is 500A, the working voltage is 80V, the argon pressure is 0.5MPa, the hydrogen pressure is 0.2MPa, the powder feeding speed is 3.5g / min, and the spraying distance is 120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4 hours at a temperature of 400℃.

[0021] Below, we evaluate the hardness and corrosion resistance (corrosive medium is 0.21 mol / L sulfuric acid solution) of the samples in Examples 1-5 and Comparative Examples 1-2. In order to ensure the comparability of the samples, the process conditions other than the rare earth content in the composite layer must be exactly the same during the experiment. The test results are shown in Table 1.

[0022] Table 1 Experimental data for each sample As shown in Table 1, incorporating rare earth element La into plasma-sprayed TiN coatings significantly improves their corrosion resistance. With increasing rare earth content, the corrosion resistance of the composite coating gradually increases, and this upward trend tends to level off. Meanwhile, the hardness of the composite coating exhibits a trend of first increasing and then decreasing. Therefore, in practice, the mass content of rare earth element La needs to be controlled between 4.3% and 10.7%.

[0023] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an anode plate for electrolytic manganese processes, characterized in that, The preparation method includes the following steps: Substrate pretreatment: Select titanium plate as substrate material and cut it into appropriate size. Then, put the substrate into 10-12wt% hydrochloric acid solution for acid washing, then put it into 5-6wt% sodium hydroxide solution for alkaline washing, and finally wash it with deionized water and dry it for use. Plasma-sprayed TiN-rare earth composite layer: Using TiN powder and rare earth La powder as raw materials, a TiN-rare earth composite layer is prepared on the substrate surface by plasma spraying. The mass content of rare earth La in the composite layer is 4.3-10.7%. During the plasma spraying process, the working current is 500-520A, the working voltage is 80-85V, the argon pressure is 0.5-0.6MPa, the hydrogen pressure is 0.2-0.5MPa, the powder feeding speed is 3.5-3.8g / min, and the spraying distance is 100-120mm. Vacuum annealing: The substrate material containing the TiN-rare earth composite layer is placed in a vacuum annealing furnace and annealed for 4-4.5 hours at a temperature of 400-450℃.

2. A preparation method as described in claim 1, characterized in that, The operating current is 500A.

3. A preparation method as described in claim 1, characterized in that, The operating voltage is 80V.

4. A preparation method as described in claim 1, characterized in that, The powder feeding speed is 3.5 g / min.

5. A preparation method as described in claim 1, characterized in that, The spraying distance is 100mm.

6. A preparation method as described in claim 1, characterized in that, The argon gas pressure is 0.5 MPa.

7. A preparation method as described in claim 1, characterized in that, The hydrogen pressure is 0.2 MPa.

8. An anode plate for use in electrolytic manganese processes, characterized in that, The anode plate is obtained by the preparation method according to any one of claims 1-7.

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