Method for treating surface of electrodeposited cobalt sheet

Abstract

The invention discloses a method for treating the surface of an electrodeposited cobalt sheet, which comprises the following steps: controlling air pressure and time, and carrying out sand blasting treatment on the electrodeposited cobalt sheet to be treated; and after the sand blasting treatment is finished, the cobalt sheet with the silver gray luster on the surface is obtained. By controlling the air pressure and time of the sand blasting treatment, the electro-deposition cobalt sheet to be treated is treated, the pollution layer on the surface of the electro-deposition cobalt sheet can be effectively removed under the condition that no acid liquor needs to be introduced, the result shows that impurities cannot be introduced into the treated electro-deposition cobalt sheet, meanwhile, the surface of the treated electro-deposition cobalt sheet presents silver gray luster, and the quality of the cobalt sheet is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cobalt surface treatment, in particular to a method for treating the surface of an electrolytically deposited cobalt sheet. Background Art

[0002] The appearance of cobalt is similar to that of pure iron or nickel, and its hardness is higher than that of iron. It is an important raw material for the production of heat-resistant alloys, cemented carbides, corrosion-resistant alloys, magnetic alloys and various cobalt salts. It is widely used in aerospace, mechanical manufacturing, electromagnetic and other fields. Cobalt with higher purity is widely used in superalloy materials, magnetic materials, and targets for advanced electronic components.

[0003] At present, the industrial methods for preparing metallic cobalt include pyrometallurgy and hydrometallurgy. Compared with pyrometallurgy, which consumes a lot of energy and requires electrolytic refining, hydrometallurgy has attracted more attention. Hydrometallurgy mainly obtains cobalt by leaching, removing impurities, enriching and electrolytically depositing the ore after crushing. The purity of electrolytic cobalt is usually very high, reaching more than 99.9%. Electrolytic cobalt can better meet the needs of the industry.

[0004] However, because the cathode plate used in electrowinning has a large area and contains organic dirt, anode mud, cobalt chloride crystals, mechanical impurities and other pollutants, the cobalt plates collected after the electrowinning need to go through processes such as washing, drying, and shearing, which makes the surface of the cobalt sheets easy to turn yellow and dark, affecting the quality of the cobalt sheets. In order to ensure the performance of electrowinning cobalt sheets, effective measures need to be taken to treat them. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a method for treating the surface of an electrolytic cobalt sheet, comprising: Control the air pressure and time to perform sandblasting on the electrolytic cobalt sheet to be treated; After the sandblasting treatment, a cobalt sheet with a silver-grey luster is obtained.

[0006] Furthermore, the air pressure is 0.2-0.6Mpa, and the time is 10-60s.

[0007] Further preferably, the air pressure is 0.36 MPa, and the time is 30 s.

[0008] Furthermore, after the sandblasting treatment is completed, the residual abrasive on the surface of the treated cobalt sheet is purged.

[0009] Furthermore, the abrasive used in the sandblasting process is at least one of white corundum sand and brown corundum with a mesh size of 200-300.

[0010] Sand blasting is a process for surface treatment of workpieces. It uses compressed air as the power to spray abrasives at high speed onto the surface of the workpiece. Through the impact and cutting action of the abrasives, the surface of the workpiece acquires a certain degree of cleanliness and different degrees of roughness.

[0011] The abrasive used in the present invention can be at least one of white corundum sand and brown corundum, preferably white corundum, which has a slightly higher hardness than brown corundum, a slightly lower toughness, high purity, good self-sharpening, strong grinding ability, low heat generation, high efficiency, acid and alkali corrosion resistance, and good high temperature resistance and thermal stability. White corundum sand is suitable for grinding fine-grained abrasives such as high-carbon steel, high-speed steel and stainless steel.

[0012] Furthermore, the electrodeposited cobalt sheet to be treated is obtained by washing, drying and shearing the electrodeposited cobalt plate.

[0013] Furthermore, the method for preparing the electrolytic cobalt plate comprises: The cobalt solution is electrolytically deposited and collected on a cathode plate to obtain an electrolytic cobalt plate.

[0014] Furthermore, the cobalt solution has a cobalt content of 60-120 g / L, a hydrogen ion concentration of 0.1-0.3 mol / L, and an oil content of <2 mg / L.

[0015] Furthermore, the electrowinning is carried out at a voltage of 60-70V and a current density of 300-400A / m 2 The temperature lasts for 125-150 hours.

[0016] Furthermore, the material of the anode plate used in the electrolytic deposition may be titanium alloy; the material of the cathode plate used in the electrolytic deposition may be titanium alloy or titanium-copper alloy.

[0017] Furthermore, the washing uses an acid solution with a hydrogen ion concentration of 2-5 mol / L.

[0018] The present invention also provides a cobalt sheet obtained by using the above-mentioned method for treating the surface of the electrolytically deposited cobalt sheet.

[0019] The present invention also provides applications of the cobalt sheet in the fields of metallurgy, catalysis, energy, and medical imaging.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention processes the electrodeposited cobalt sheet to be processed by controlling the air pressure and time of the sandblasting process, and can effectively remove the surface contamination layer of the electrodeposited cobalt sheet without introducing acid solution. The results show that the treated electrodeposited cobalt sheet does not introduce impurities, and the surface presents a silver-grey luster, thereby improving the quality of the cobalt sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A photograph of the electrodeposited cobalt sheet prepared in Example 1 is shown; Figure 2 A photograph of the cobalt sheet after treatment in Example 1 is shown; Figure 3 A photograph of the cobalt sheet after treatment in Example 2 is shown; Figure 4 A photograph of the cobalt sheet after treatment in Example 3 is shown; Figure 5 A photograph of the cobalt sheet after treatment in Example 4 is shown; Figure 6 A photograph of the cobalt sheet after treatment in Example 5 is shown. DETAILED DESCRIPTION

[0023] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0024] The following will be combined with the specific embodiments of the present invention and the drawings of the specification to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1 A method for treating the surface of an electrolytic cobalt sheet comprises the following steps: S1. Preparation of electrolytic cobalt sheets 1. Cobalt concentrate, cobalt-copper alloy or crude cobalt salt is used as raw material, sulfuric acid is used for leaching, and after the leaching solution is iron-removed, P204 extractant is used for extraction and impurity removal; then P507 extractant is used for extraction and cobalt extraction, and hydrochloric acid is used for back extraction to obtain a cobalt chloride solution, and after deoiling and filtering to remove solid impurities, a cobalt chloride solution with a cobalt content of 100 g / L, a hydrogen ion concentration of 0.2 mol / L, and an oil content of <2 mg / L is obtained; 2. Electrolysis is carried out in a closed electrolytic cell. The anode plate and the material of the anode plate are titanium alloy. The voltage is 65V and the current density is 350A / m 2 The electroplating was continued for 140 hours. After the electroplating was completed, the electroplated cobalt plates were collected on the cathode plate. 3. Wash the electrolytic cobalt plate with 3 mol / L hydrochloric acid, cold water and hot water in turn to remove impurities and crystals on the surface. After dehumidification and drying, cut the plate to obtain a 5 cm × 5 cm electrolytic cobalt sheet.

[0026] S2. Treatment of electrolytic cobalt sheets like Figure 1 As shown, the surface of the prepared electrolytic cobalt sheet is yellow, black and dark, which has seriously affected the appearance quality of the cobalt sheet and needs to be treated on the surface. The details are as follows: The electro-deposited cobalt sheet to be treated is placed on an automatic sandblasting machine, and the sandblasting time is adjusted by adjusting the push plate speed. The sandblasting lasts for 30 seconds at an air pressure of 0.36 MPa. 240-mesh white corundum sand is used to grind the front and back sides of the electro-deposited cobalt sheet to be treated. After grinding, compressed air is used to blow away the residual white corundum sand on the surface of the cobalt sheet to obtain a cobalt sheet with a silver-gray luster on the surface.

[0027] Example 2 A method for treating the surface of an electrolytic cobalt sheet. The electrolytic cobalt sheet and Example 1 are prepared from the same batch. The difference between the electrolytic cobalt sheet and Example 1 is that in the treatment of the electrolytic cobalt sheet, the sandblasting treatment is continued for 40 seconds at an air pressure of 0.25 MPa.

[0028] Example 3 A method for treating the surface of an electrolytic cobalt sheet. The electrolytic cobalt sheet and Example 1 are prepared from the same batch. The difference between the electrolytic cobalt sheet and Example 1 is that in the treatment of the electrolytic cobalt sheet, the sandblasting treatment is continued for 15 seconds at an air pressure of 0.30 MPa.

[0029] Example 4 A method for treating the surface of an electrolytic cobalt sheet. The electrolytic cobalt sheet and Example 1 are prepared from the same batch. The difference between the electrolytic cobalt sheet and Example 1 is that in the treatment of the electrolytic cobalt sheet, the sandblasting treatment is continued for 50 seconds at an air pressure of 0.36 MPa.

[0030] Example 5 A method for treating the surface of an electrolytic cobalt sheet. The electrolytic cobalt sheet and Example 1 are prepared from the same batch. The difference between the electrolytic cobalt sheet and Example 1 is that in the treatment of the electrolytic cobalt sheet, the sandblasting treatment is continued for 30 seconds at an air pressure of 0.56 MPa.

[0031] Table 1 shows the air pressure and time of the sandblasting treatment in Examples 1-5.

[0032] Table 1 Air pressure and time of sandblasting

[0033] The cobalt flakes obtained in Examples 1-5 are respectively as follows Figure 2-6 As shown. The surface of the cobalt sheet of Example 1 presents a silver-gray luster and is smooth; the surface of the cobalt sheet of Example 2 presents a dark silver-gray luster, and the surface is uneven with uneven protrusions; the dark part of the surface of the cobalt sheet of Example 3 is not covered (accounting for about 40% of the area of ​​the cobalt sheet); the surface of the cobalt sheet of Example 4 presents a dark gray color, and the grinding time is longer than that of Example 1, the time cost increases, and the efficiency decreases instead; Example 5 uses a higher air pressure for grinding, and the surface of the cobalt sheet presents a silver-gray luster, but because the sandblasting pressure is too high, there are scratches on the surface of the drill sheet. These results, combined with the parameters in Table 1, show that using appropriate air pressure and grinding for an appropriate time is more beneficial to improving the quality of the cobalt sheet.

[0034] Atomic absorption spectroscopy (AAS) was also used to test the element content of the electrolytic cobalt sheet before treatment and the cobalt sheet after treatment in Example and Example 2. The results are shown in Table 2. The remainder in Table 2 is Co (>99.9%, not shown in the table), and a small amount of C and S (both within the limit, not shown in the table).

[0035] Table 2 Element content of cobalt flakes (%)

[0036] It can be seen from the results in Table 2 that the treatment method of the present invention does not introduce obvious impurities, and while ensuring that the cobalt flakes present a silver-grey luster, it does not bring any negative effects and can improve the quality of the cobalt flakes.

[0037] In summary, the present invention processes the electrodeposited cobalt sheet to be processed by controlling the air pressure and time of the sandblasting treatment. Without the need to introduce acid solution, the surface contamination layer of the electrodeposited cobalt sheet can be effectively removed. The results show that the treated electrodeposited cobalt sheet does not introduce impurities, and the surface presents a silver-gray luster, thereby improving the quality of the cobalt sheet.

[0038] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for treating the surface of an electrolytically deposited cobalt sheet, characterized in that: include, Control the air pressure and time to perform sandblasting on the electrolytic cobalt sheet to be treated; After the sandblasting treatment, a cobalt sheet with a silver-grey luster is obtained.

2. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 1, characterized in that: The air pressure is 0.2-0.6Mpa, and the time is 10-60s.

3. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 1, characterized in that: The air pressure is 0.36 MPa, and the time is 30 seconds.

4. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 1, characterized in that: After the sandblasting process is completed, the residual abrasive on the surface of the treated cobalt sheet is purged.

5. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 1, characterized in that: The abrasive used in the sandblasting process is at least one of white corundum sand and brown corundum with a mesh size of 200-300.

6. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 1, characterized in that: The electrodeposited cobalt sheet to be treated is obtained by washing, drying and shearing the electrodeposited cobalt plate.

7. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 6, characterized in that: The method for preparing the electrolytic cobalt plate comprises: The cobalt solution is electrolytically deposited and collected on a cathode plate to obtain an electrolytic cobalt plate.

8. The method for treating the surface of an electrolytically deposited cobalt sheet according to claim 7, characterized in that: The cobalt solution has a cobalt content of 60-120 g / L, a hydrogen ion concentration of 0.1-0.3 mol / L, and an oil content of <2 mg / L; The electrolytic deposition is carried out at a voltage of 60-70V and a current density of 300-400A / m 2 The temperature lasts for 125-150 hours.

9. A cobalt sheet, characterized in that: The method for treating the surface of an electrolytically deposited cobalt sheet according to any one of claims 1 to 8 is used to obtain the cobalt sheet.

10. Use of the cobalt sheet according to claim 9 in the fields of metallurgy, catalysis, energy, and medical imaging.

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