Nonlinear Current Electrolysis Method for Manganese Electrodeposition and Its Application

Abstract

The present invention discloses a nonlinear current electrolysis method for manganese electrodeposition and its application. The nonlinear current of the present invention is output by a nonlinear power supply. The output current exhibits continuous periodic variation over time, with the periodic variation interval selectable within [0, 20]A. The current frequency is between 1 and 1,000,000 Hz, and the current waveform is one of a sine wave, square wave, triangle wave, noise wave, and dualtone wave. The present invention's nonlinear current electrolysis of manganese with quasi-periodic characteristics and continuous variation achieves energy conservation and consumption reduction during long-term manganese electrodeposition. It also significantly regulates cathode interface concentration polarization, significantly improving the current efficiency of manganese electrodeposition and reducing anode mud generation, thereby improving the quality and quality of the deposited manganese.

Description

Technical Field

[0001] The present invention relates to the field of electrolytic manganese technology, and in particular to a nonlinear current electrolytic method for manganese electrodeposition and its application. Background Art

[0002] Manganese is one of the important metals, widely used in steel smelting, alloy, new energy and other industries, and is an indispensable raw material for basic industries. At present, the traditional electrolytic manganese industry is powered by a DC power supply under the MnSO4-(NH4)2SO4 electrolyte system, at a high cathode current density (300-350A / m 2 ) is used for cathode electroreduction to obtain metallic manganese. During the DC electrodeposition process, Mn near the cathode surface 2+ As the electrodeposition process proceeds, it is gradually depleted. This leads to the formation of a thick diffusion layer at the interface between the cathode and the solution, resulting in concentration polarization and reducing the metal deposition rate. When the cathode concentration polarization is severe, the hydrogen evolution reaction will be severely aggravated. In addition, the Mn deposited layer obtained by DC electrodeposition is loose and porous, with weak density. And during the electrodeposition process, the manganese reduction potential is too negative (-1.18V vs. SHE), which causes problems of high cell voltage and high electrolysis energy consumption. The DC power consumption per ton of manganese is 5800-6200kW·h, while the electrolysis efficiency is only 65%-74%. Under DC electrolysis, due to the severe concentration polarization problem, high cell voltage and high electrolysis energy consumption will occur, resulting in reduced quality of manganese products. Some researchers have regulated the electrolysis of metallic manganese by changing the power supply to pulsed current electrolysis. Results show that pulsed current electrolysis has a certain effect on energy conservation and improving the quality of manganese deposition. However, the pulsed current is a continuous on-off cycle, which still produces concentration polarization during the electrodeposition process, causing cathode dendrite growth. Furthermore, the pulsed current mode is half on time and half off time. During the off time, the electrodeposition reaction stops, causing manganese dissolution, which is not conducive to manganese deposition and leads to a reduction in manganese deposition. Therefore, changing the power supply during the electrolysis process and finding an adjustable electrolysis method with continuous current variation characteristics is expected to become a new breakthrough in achieving energy conservation and consumption reduction in the manganese electrolysis process. Summary of the Invention

[0003] In view of this, the present invention provides a novel nonlinear current electrolysis method for manganese electrodeposition, which aims to achieve continuous, nonlinear power supply, solve the concentration polarization technical problem of manganese electrodeposition, and achieve energy saving and consumption reduction in the long-term manganese electrodeposition process, thereby improving current efficiency and improving the quality and quality of manganese deposition. In detail, one of the objects of the present invention is to provide a nonlinear current electrolysis method for manganese electrodeposition, comprising the following steps: (1) adding a manganese sulfate solution system to an electrolytic cell; (2) adjusting the power supply parameters of a nonlinear power supply to electrolyze the manganese sulfate solution system to precipitate elemental metallic manganese at the cathode; the magnitude of the current output by the nonlinear power supply varies continuously and periodically over time; the power supply parameters of the nonlinear power supply are as follows: adjusting the continuous periodic variation interval of the magnitude of the current, wherein the variation interval is selected within the range of [0, 20] A; adjusting the frequency of the current to be 1 to 1000000 Hz; adjusting the waveform of the current to be one of a sine wave, a square wave, a triangle wave, a noise wave, and a dualtone wave; and (3) subjecting the metallic manganese deposited at the cathode after electrolysis to a treatment including passivation, cleaning, drying, and stripping steps to obtain a high-purity metallic manganese product. The selection of the variation interval within the range of [0, 20] A means that [0, 20] A is the maximum variation interval (the current varies continuously and periodically from 0 A to 20 A), and any smaller interval value within the maximum variation interval can be selected.

[0004] Preferably, the manganese sulfate solution system in step (1) is: the concentration of ammonium sulfate is 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is 7.0; the periodic change interval value of the magnitude of the current adjustment in step (2) is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 The frequency of the current adjustment in step (2) is 500 Hz. [0.43, 0.46] A means that the current changes continuously and periodically from 0.43 A to 0.46 A, and the average current density is required to be 350 A / m 2 ; [0.44, 0.51] A means that the current changes continuously and periodically from 0.44 A to 0.51 A, and the average current density is required to be 400 A / m 2 .

[0005] Preferably, the anode material of the electrodes of the electrolytic cell is a quaternary alloy, and the cathode material is stainless steel.

[0006] Preferably, the electrolyte temperature in the electrolytic cell is 35°C.

[0007] Preferably, the waveform of the regulating current is a Dualtone wave.

[0008] A second object of the present invention is to provide an application of a nonlinear current in reducing anode mud in a manganese electrodeposition electrolytic system. The parameters of the nonlinear current are as follows: the current magnitude varies continuously and periodically over time, and the current magnitude variation range is any range in the range [0, 20] A; the current frequency is 1 to 1000000 Hz; the current waveform is one of a sine wave, a square wave, a triangle wave, a noise wave, and a dualtone wave; and the manganese electrodeposition electrolytic system is a manganese sulfate solution system.

[0009] Preferably, the manganese sulfate solution system is: ammonium sulfate concentration is 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is 7.0; the current size variation range is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 ; The frequency of the current is 500Hz.

[0010] A third object of the present invention is to provide an application of a nonlinear current in improving the current efficiency of a manganese electrodeposition electrolytic system, wherein the parameters of the nonlinear current are as follows: the magnitude of the current varies continuously and periodically over time, and the current magnitude varies within any interval of [0, 20] A; the frequency of the current is 1 to 1,000,000 Hz; the waveform of the current is one of a sine wave, a square wave, a triangle wave, a noise wave, and a dualtone wave; and the manganese electrodeposition electrolytic system is a manganese sulfate solution system.

[0011] Preferably, the manganese sulfate solution system is: ammonium sulfate concentration is 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is 7.0; the current size variation range is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 ; The frequency of the current is 500Hz.

[0012] Beneficial Effects: The nonlinear current electrolysis method and application for manganese electrodeposition provided by the present invention is a novel nonlinear current electrolysis method and new application for manganese electrodeposition. The nonlinear current of the present invention is output by a nonlinear power supply, and the output current magnitude varies continuously and periodically over time. The periodic variation interval value can be selected from [0, 20] A, the current frequency is between 1 and 1000000 Hz, and the current waveform is a wave selected from sine, square, triangle, noise, and dualtone waves. The nonlinear current electrolysis of manganese with quasi-periodic characteristics and continuous variation of the present invention achieves energy conservation and consumption reduction in the long-term manganese electrodeposition process, while greatly regulating the cathode interface concentration polarization, greatly improving the current efficiency of manganese electrodeposition and reducing the generation of anode mud, thereby improving the quality and quality of the deposited manganese. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the electrolysis flow chart of the present invention;

[0014] Figure 2 This is a sinusoidal current signal diagram of the present invention;

[0015] Figure 3 This is a square wave current signal diagram of the present invention;

[0016] Figure 4 This is the Dualtone wave current signal diagram of the present invention;

[0017] Figure 5 This is a microscopic image of electrolytic cathode manganese deposition in the present invention. DETAILED DESCRIPTION

[0018] The endpoints of any ranges and any values ​​disclosed herein are not limited to the precise ranges and / or values, and these ranges and / or values ​​can and should be understood to include values ​​close to these ranges and / or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to form one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0019] Example 1:

[0020] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0021] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1, pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to a sine wave current signal, set the periodic change interval value of the current size to [0.43, 0.46] A, and the average current density to 350A / m 2 , set the current frequency to 500Hz, and the sine wave current signal as shown in the attached Figure 2 The manganese sulfate solution is electrolyzed to precipitate elemental manganese metal at the cathode; the manganese metal deposited at the cathode after electrolysis is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce manganese metal products with higher purity.

[0022] Example 2:

[0023] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0024] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to a sine wave current signal, set the periodic change interval value of the current size to [0.44, 0.51] A, and the average current density to 400A / m 2 , setting the current frequency to 500 Hz; electrolyzing the manganese sulfate solution to precipitate elemental metallic manganese at the cathode; after electrolysis, the metallic manganese deposited at the cathode is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce metallic manganese products with higher purity.

[0025] Example 3:

[0026] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0027] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to a square wave current signal, set the periodic change interval value of the current size to [0.43, 0.46] A, and the average current density to 350A / m 2 , set the current frequency to 500Hz, and the square wave current signal as shown in the attached Figure 3The manganese sulfate solution is electrolyzed to precipitate elemental manganese metal at the cathode; the manganese metal deposited at the cathode after electrolysis is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce manganese metal products with higher purity.

[0028] Example 4:

[0029] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0030] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to a square wave current signal, set the periodic change interval value of the current size to [0.44, 0.51] A, and the average current density to 400A / m 2 , setting the current frequency to 500 Hz; electrolyzing the manganese sulfate solution to precipitate elemental metallic manganese at the cathode; after electrolysis, the metallic manganese deposited at the cathode is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce metallic manganese products with higher purity.

[0031] Example 5:

[0032] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0033] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to Dualtone wave current signal, set the periodic change interval value of the current size to [0.43, 0.46] A, and the average current density to 350A / m 2 , set the current frequency to 500Hz, and the Dualtone wave current signal as shown in the attached Figure 4 The manganese sulfate solution is electrolyzed to precipitate elemental manganese metal at the cathode; the manganese metal deposited at the cathode after electrolysis is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce manganese metal products with higher purity.

[0034] Example 6:

[0035] 1) A nonlinear power supply supplies power to the manganese electrolysis system;

[0036] 2) Add manganese sulfate solution to the electrolytic cell. The manganese sulfate solution system is ammonium sulfate with a concentration of 120g·L -1 , the manganese ion concentration is 30g·L -1 , SeO2 concentration is 30 mg·L -1 , pH value is about 7.0, place the electrode in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; connect the nonlinear power supply, adjust the power supply parameters: set the nonlinear current to Dualtone wave current signal, set the periodic change interval value of the current size to [0.44, 0.51] A, and the average current density to 400A / m 2 , setting the current frequency to 500 Hz; electrolyzing the manganese sulfate solution to precipitate elemental metallic manganese at the cathode; after electrolysis, the metallic manganese deposited at the cathode is subjected to post-processing operations such as passivation, cleaning, drying, and stripping to produce metallic manganese products with higher purity.

[0037] Comparative Example:

[0038] Comparative test of nonlinear current electrolysis for manganese electrodeposition: Under the same electrolytic solution system conditions as in the above experimental example, with the same type of electrode materials, the current frequency is 500Hz and the current density is 350A / m 2 or 400A / m 2 Under the electrolysis conditions, direct current electrolysis was carried out as a comparative experiment.

[0039] result:

[0040] The difference in the mass of the dry electrode before and after electrolysis is used to obtain the cathode manganese precipitation weight and the anode mud mass, and the current efficiency CE is calculated according to Formula 1. Under the same conditions, the electrolysis experiment is carried out, and a nonlinear power supply is used as the manganese electrolysis power supply to output nonlinear currents with different waveform characteristics. The electrolysis flow chart is shown in the attached figure. Figure 1 As shown in the figure, the waveform characteristics of sine wave, square wave and Dualtone wave are shown in the figure. Figure 2 , Attachment Figure 3 and attached Figure 4 The electrolysis process parameters and their effects are shown in Table 1. Under DC conditions, the current efficiency is as high as 80.2%. After using different nonlinear currents, the current efficiency is generally improved by 4.8% to 7.9%, while reducing the amount of anode mud generated during the electrolysis process. When the nonlinear power supply parameters are set to Dualtone wave current signal and current density 400A / m 2 Under this condition, the effect is the best, the current efficiency can reach 88.1%, a relative increase of 7.9%, and the anode mud is reduced by 50%. Under the nonlinear power supply Dualtone wave electrolysis, the electrolysis efficiency is high, the electrolysis process energy saving effect is obvious, and the anode mud pollution is greatly reduced, effectively improving the quality of manganese precipitation. At a current density of 400A / m2 The growth of cathode metal dendrites under nonlinear current power supply electrolysis is compared with that under DC power supply electrolysis. Figure 5 As shown, among them, (a) direct current electrolysis, (b) sinusoidal wave current electrolysis, (c) square wave current electrolysis, and (d) dualtone wave electrolysis. It can be seen that when using direct current power supply electrolysis, the number of cathode metal dendrites is large, and the dendrite particles grow densely in the center and edge of the cathode. When using nonlinear current power supply electrolysis, the number of cathode metal dendrites is significantly reduced. Among them, the result under the dualtone wave current signal is the best. The surface of the cathode manganese deposit is smooth and dense, the color is bright white, and there are only a small amount of granular dendrites at the edge of the cathode, and the deposition quality is the best.

[0041] CE=Δm / (q·i·Δt) (1)

[0042] Table 1 Parameters and effects of different types of nonlinear current electrolysis

[0043]

[0044] The conventional techniques in the above-mentioned embodiments and the schemes not described in detail are all well known in the art, so they are not described in detail here. The above embodiments and / or experimental examples describe the preferred embodiments of the present invention in detail, but the present invention is not limited to the specific details in the above-mentioned embodiments. Within the scope of the technical concept of the present invention, the technical scheme of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above-mentioned specific embodiments can be combined in any suitable manner when there is no contradiction. In order to avoid unnecessary repetition, the present invention will no longer describe various possible combinations separately. In addition, any combination can also be carried out between the various different embodiments of the present invention, as long as it does not violate the idea of ​​the present invention, it should also be regarded as the content disclosed by the present invention.

Claims

1. A non-linear current electrolysis method for manganese electrodeposition, characterized in that: The following steps are involved: (1) Adding a manganese sulfate solution system to the electrolytic cell; (2) adjusting the power parameters of the nonlinear power supply to electrolyze the manganese sulfate solution system and precipitate elemental metallic manganese at the cathode; the magnitude of the current output by the nonlinear power supply changes continuously and periodically over time; the power parameters of the nonlinear power supply are: adjusting the continuous periodic change interval of the magnitude of the current; adjusting the waveform of the current to be a square wave or a dualtone wave; (3) Processing the manganese metal deposited on the cathode after electrolysis through passivation, cleaning, drying, and stripping steps to obtain a high-purity manganese metal product; The manganese sulfate solution system in step (1) is: the concentration of ammonium sulfate is 120 g·L -1 , the manganese ion concentration is 30 g•L -1 , SeO2 concentration is 30 mg•L -1 , pH value is 7.0; the periodic change interval value of the magnitude of the current adjustment in step (2) is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 ; The frequency of the regulating current described in step (2) is 500 Hz.

2. The method according to claim 1, wherein The anode material of the electrode of the electrolytic cell is a quaternary alloy, and the cathode material is stainless steel.

3. The method according to claim 1, wherein The electrolyte temperature in the electrolytic cell is 35 °C.

4. Application of nonlinear current in reducing anode mud in manganese electrodeposition electrolysis system, characterized in that: The parameters of the nonlinear current are: the current magnitude changes continuously and periodically over time; the current waveform is a square wave or a dualtone wave; the manganese electrodeposition electrolysis system is a manganese sulfate solution system; The manganese sulfate solution system is as follows: the concentration of ammonium sulfate is 120 g·L -1 , the manganese ion concentration is 30 g•L -1 , SeO2 concentration is 30 mg•L -1 , pH value is 7.0; the current size range is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 ; The frequency of the current is 500 Hz.

5. Application of nonlinear current in improving the current efficiency of manganese electrodeposition electrolysis system, characterized in that: The parameters of the nonlinear current are: the current magnitude changes continuously and periodically over time; the current waveform is a square wave or a dualtone wave; the manganese electrodeposition electrolysis system is a manganese sulfate solution system; The manganese sulfate solution system is as follows: the concentration of ammonium sulfate is 120 g·L -1 , the manganese ion concentration is 30 g•L -1 , SeO2 concentration is 30 mg•L -1 , pH value is 7.0; the current size range is [0.43, 0.46] A or [0.44, 0.51] A, and the average current density at [0.43, 0.46] A is 350 A / m 2 , so that the average current density at [0.44, 0.51] A is 400 A / m 2 ; The frequency of the current is 500 Hz.

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