Coupled Current Electrolysis Method for Manganese Electrodeposition

Abstract

The present invention discloses a coupled current electrolysis method for manganese electrodeposition, comprising the following steps: (1) adding a manganese sulfate solution system to an electrolytic cell; (2) connecting a coupled current source for electrolysis; the coupled current source comprising a direct current circuit and a chaotic circuit, wherein the anode of the direct current circuit and the anode of the chaotic circuit are connected to the anode of the electrolytic cell, and the cathode of the direct current circuit and the cathode of the chaotic circuit are connected to the cathode of the electrolytic cell. The current output by the coupled current source of the present invention exhibits continuous periodic variation over time, and the current amplitude is adjustable. The coupled electrolysis operation is simple, the current efficiency is high, and the electrolysis energy consumption is low. At the same time, the electrodeposition effect is improved, the lead content in the electrolysis product is reduced, which is conducive to manganese nucleation, achieves uniform and dense manganese deposition, and improves the quality of the manganese product.

Description

Technical Field

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

[0002] Manganese is a key metal widely used in industries such as steelmaking, alloys, and new energy, and is an indispensable raw material for basic industries. Currently, the traditional electrolytic manganese industry is powered by direct current (DC) power. During DC electrodeposition, the resulting Mn deposit is loose and porous, lacking density. Furthermore, the manganese reduction potential during electrodeposition is excessively negative, leading to high cell voltage and high electrolysis energy consumption. DC power consumption ranges from 5800 to 6200 kW·h per ton of manganese, while electrolysis efficiency is only 65% ​​to 74%. Severe concentration polarization under DC electrolysis leads to high cell voltage and high electrolysis energy consumption, resulting in reduced manganese product quality. Researchers have attempted to manipulate manganese electrolysis by switching to pulsed current electrolysis. Results indicate that pulsed current electrolysis offers some benefits in energy savings and improving the quality of deposited manganese. However, the continuous on-off switching of the pulsed current can still generate concentration polarization during the electrodeposition process, leading to cathode dendrite growth. Furthermore, the single electrolysis current suffers from a single current amplitude, which prevents effective coupling of the electrolysis process. Therefore, changing the power supply of the electrolysis process and finding an electrolysis method with adjustable current amplitude and continuous current change characteristics is expected to become a new breakthrough in achieving energy saving and consumption reduction in the manganese metal electrolysis process. Summary of the Invention

[0003] In view of this, the present invention provides a novel coupled current electrolysis method for manganese electrodeposition, which aims to achieve continuous, nonlinear, and adjustable power supply, solve the concentration polarization problem of manganese electrodeposition, and achieve energy saving and consumption reduction during long-term manganese electrodeposition, thereby improving current efficiency and improving the quality and quality of manganese deposition. In detail, the coupled current electrolysis method for manganese electrodeposition provided by the present invention includes the following steps:

[0004] (1) adding a manganese sulfate solution system to an electrolytic cell;

[0005] (2) connecting a coupled current source to perform electrolysis;

[0006] The coupling current source includes a DC circuit and a chaotic circuit, the anode of the DC circuit and the anode of the chaotic circuit are connected to the anode of the electrolytic cell, and the cathode of the DC circuit and the cathode of the chaotic circuit are connected to the cathode of the electrolytic cell; the coupling current source is turned on by turning on the power switch of the DC circuit and the power switch of the chaotic circuit.

[0007] 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 average current density of the coupling current source in step (2) is 350A / m 2 .

[0008] Preferably, the magnitudes of the currents of the DC circuit and the chaotic circuit are both adjustable.

[0009] Preferably, the current ratio of the DC circuit to the chaotic circuit is 2:8 to 8:2.

[0010] Preferably, the current ratio of the DC circuit to the chaotic circuit is 4:6.

[0011] Preferably, the anode material of the electrodes of the electrolytic cell is a quaternary alloy, and the cathode material is stainless steel.

[0012] Preferably, the electrolyte temperature in the electrolytic cell is 40°C.

[0013] The method of the present invention comprises a coupled current source provided by a chaotic circuit with a continuously changing current signal and a linear term with adjustable magnitude to increase the current value through a direct current circuit. The current amplitude (current fluctuation range) is changed by adjusting the current ratio of the direct current circuit power supply and the chaotic circuit power supply. Coupled currents of different proportions are introduced to electrolyze the manganese sulfate solution system, and elemental metallic manganese is precipitated at the cathode. The magnitude of the current output by the coupled current source varies continuously and periodically over time. The coupled currents are combined in different proportions. Under the same current parameter, the coupled currents can output multiple current signals with different current amplitudes. The coupled currents have different current amplitudes when they have different proportions.

[0014] Beneficial effects: The coupled current electrolysis method for manganese electrodeposition provided by the present invention is a new manganese electrodeposition method. The current output by the coupled current source of the present invention changes continuously and periodically over time, the current amplitude is adjustable, and the coupled electrolysis operation is simple. Under a specific coupling current ratio, the current efficiency is 4.25% higher than that of direct current, and the electrolysis energy consumption is 5.08% lower than that of direct current. The anode mud is reduced by 27.99% respectively. At the same time, the electrodeposition effect is improved, and the lead content in the electrolysis product is reduced. This is conducive to the nucleation of manganese, realizes uniform and dense deposition of manganese, and improves the quality of manganese products. At the same time, this coupled electrolysis method is not only simple to operate, but also achieves clean and efficient electrolysis effects in the actual electrolysis process, and is operational for the hydrometallurgical industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the electrolysis process of the present invention;

[0016] Figure 2 1 is a circuit structure diagram of a chaotic circuit according to an embodiment of the present invention;

[0017] Figure 3 The microscopic morphology of cathode manganese deposition under different currents of the present invention;

[0018] Figure 4 The microscopic morphology of anode mud under different currents of the present invention. DETAILED DESCRIPTION

[0019] 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.

[0020] Implementation 1: Coupling Current Source and Its Connection to the Electrolytic Cell

[0021] The coupling current source consists of two circuits: a DC circuit and a chaotic circuit. The DC circuit outputs DC current, and the chaotic circuit outputs chaotic current. That is, the coupling current is obtained by coupling the DC current and the chaotic current ( Figure 1 The coupling current source and its connection method to the electrolytic cell are as follows: the anodes of the DC circuit and the chaotic circuit are simultaneously connected to a single wire, designated as wire 1. This wire serves as the anode of the coupling current source, and wire 1 is then connected to the anode of the electrolytic cell. Similarly, the cathodes of the DC circuit and the chaotic circuit are simultaneously connected to another wire, designated as wire 2. This wire serves as the cathode of the coupling current source, and wire 2 is then connected to the cathode of the electrolytic cell. When the power switches of the DC circuit and the chaotic circuit are turned on, the two currents are coupled, forming a coupled current. The electrolytic cell then connects to the coupled current and begins electrolysis.

[0022] The DC circuit of the coupled current source is: a DC current power supply that can be adjusted and generate different current sizes.

[0023] The chaotic circuit of the coupled current source is a chaotic current power supply that can adjust and generate different current sizes. The circuit structure of the power supply includes a chaotic module and a current amplification module. The chaotic module generates chaotic current, and the current amplification module can amplify and adjust the size of the chaotic current.

[0024] Circuit structure of chaos module ( Figure 2 ) is: the VS+ terminal of the analog multiplier U6 is connected to the positive terminal of the DC power supply, and the VS- terminal is connected to the negative terminal of the DC power supply, and the DC power supply provides a 15V voltage signal for the circuit;

[0025] The Z terminal, X2 terminal, Y1 terminal and Y2 terminal of the analog multiplier U6 are grounded;

[0026] The X1 terminal of the analog multiplier U6 receives the signal fed back by the operational amplifier L1;

[0027] The Y1 terminal of the analog multiplier U6 receives the signal fed back by the operational amplifier L7;

[0028] The analog multiplier U6 multiplies the received signals to obtain a multiplied signal;

[0029] The W terminal of the analog multiplier U6 transmits the multiplied signal to the negative input terminal of the operational amplifier L1 through the resistor R3;

[0030] The negative input terminal of the operational amplifier L1 receives the signal fed back by the operational amplifier L2 through the resistor R1;

[0031] The negative input terminal of the operational amplifier L1 receives the signal fed back by the operational amplifier L3 through the resistor R2;

[0032] The negative input terminal of the operational amplifier L1 receives the signal fed back by the operational amplifier L4 through the resistor R4;

[0033] The positive input terminal of the operational amplifier L1 is grounded;

[0034] The output terminal of the operational amplifier L1 is connected in series with the capacitor C1 and then connected to the negative input terminal of the operational amplifier L1;

[0035] The output terminal of the operational amplifier L1 is connected in series with a resistor R13 and then connected to the negative input terminal of the operational amplifier L2;

[0036] The positive input terminal of the operational amplifier L2 is grounded;

[0037] The signal output from the output terminal of the operational amplifier L2 enters the negative input terminal of the operational amplifier L3 through the resistor R5;

[0038] The output terminal of the operational amplifier L2 is connected in series with a resistor R14 and then connected to the negative input terminal of the operational amplifier L2;

[0039] The negative input terminal of the operational amplifier L3 receives the signal fed back by the operational amplifier L3 through the resistor R6;

[0040] The positive input terminal of the operational amplifier L3 is grounded;

[0041] The output terminal of the operational amplifier L3 is connected in series with the capacitor C2 and then connected to the negative input terminal of the operational amplifier L3;

[0042] The negative input terminal of the operational amplifier L4 receives the signal fed back by the operational amplifier L2 through the resistor R7;

[0043] The positive input terminal of the operational amplifier L4 is grounded;

[0044] The output terminal of the operational amplifier L4 is connected in series with the capacitor C3 and then connected to the negative input terminal of the operational amplifier L4;

[0045] Circuit structure of current amplifier module ( Figure 2 ) is: the Z terminal, X2 terminal, Y1 terminal and Y2 terminal of the analog multiplier U7 are grounded;

[0046] The X1 terminal of the analog multiplier U7 receives the signal fed back by the operational amplifier L2;

[0047] The Y1 terminal of the analog multiplier U7 receives the signal fed back by the operational amplifier L1;

[0048] The VS+ terminal of the analog multiplier U7 is connected to the positive terminal of the DC power supply, and the VS- terminal is connected to the negative terminal of the DC power supply;

[0049] The analog multiplier U7 multiplies the received signals to obtain a multiplied signal;

[0050] The W terminal of the analog multiplier U7 transmits the multiplied signal to the negative input terminal of the operational amplifier L5 through the resistor R9;

[0051] The negative input terminal of the operational amplifier L5 receives the electrical signal flowing through the resistor R16 via the resistor R17;

[0052] The negative input terminal of the operational amplifier L5 is connected in series with a capacitor C4 and then connected to the output terminal of the operational amplifier L5;

[0053] The positive input terminal of the operational amplifier L5 is grounded;

[0054] The output terminal of the operational amplifier L5 is connected to the negative input terminal of the operational amplifier L6 through the resistor R16;

[0055] The negative input terminal of the operational amplifier L6 is connected in series with a resistor R15 and then connected to the anode of the diode D3;

[0056] The positive input terminal of the operational amplifier L6 is grounded;

[0057] The output terminal of the operational amplifier L6 is connected in series with the cathode of the diode D3;

[0058] The anode of the diode D3 is connected in series with the resistor R11 and the resistor R10 in sequence and then connected to the output end of the operational amplifier L7;

[0059] The anode of the diode D3 is connected in series with the resistor R11 and then connected to the negative input terminal of the operational amplifier L7;

[0060] The negative terminal of the power supply V1 is grounded, and the positive terminal is connected in series with a resistor R12 and then connected to the negative input terminal of the operational amplifier L7;

[0061] The positive input terminal of the operational amplifier L7 is grounded;

[0062] The component parameters in the above circuit structure are as follows: C1=C2=C3=C4=10nF, R1=R2=22.22kΩ, R3=R10=R12=R13=R14=R15=R16=10kΩ, R4=100kΩ, R5=R6=18.18kΩ, R7=500kΩ, sliding resistor R9=(0-10)kΩ, sliding resistor R11=(0-2.5)kΩ, power supply V1=4.5V.

[0063] The chaotic current power supply can be adjusted and generates different current sizes by adjusting the resistance values ​​of the sliding resistors R9 and R11 in the circuit amplification module.

[0064] Next, the coupled current source is used in a specific electrolysis experiment (see Examples 1-4 in the second embodiment below). The DC circuit and chaotic circuit constituting the coupled current source are also used in an electrolysis experiment as comparative examples (see Comparative Examples 1-2 in the second embodiment below):

[0065] Implementation Method 2: Examples and Comparative Examples Methods and Results Analysis

[0066] Example 1:

[0067] 1) coupling a current source to supply power to the manganese electrolysis system;

[0068] 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, the anode material of the electrode in the electrolytic cell is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (Total current 0.78A), adjust the current output by the DC circuit and the chaotic circuit. According to the coupling current ratio of DC: chaotic current = 8:2, set the DC current to 0.624A and the chaotic current to 0.156A. At this time, the coupling current amplitude is 0.01A. Turn on the coupling current source, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0069] Example 2:

[0070] 1) coupling a current source to supply power to the manganese electrolysis system;

[0071] 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, the anode material of the electrode in the electrolytic cell is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (Total current 0.78A), adjust the current output by the DC circuit and the chaotic circuit. According to the coupling current ratio of DC: chaotic current = 6:4, set the DC current to 0.468A and the chaotic current to 0.312A. At this time, the coupling current amplitude is 0.014A. Connect the coupling current source, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0072] Example 3:

[0073] 1) coupling a current source to supply power to the manganese electrolysis system;

[0074] 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, the anode material of the electrode in the electrolytic cell is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (Total current 0.78A), adjust the current output by the DC circuit and the chaotic circuit. According to the coupling current ratio of DC: chaotic current = 4:6, set the DC current to 0.312A and the chaotic current to 0.468A. At this time, the coupling current amplitude is 0.017A. Turn on the coupling current source, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0075] Example 4:

[0076] 1) coupling a current source to supply power to the manganese electrolysis system;

[0077] 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, the anode material of the electrode in the electrolytic cell is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (Total current 0.78A), adjust the current output by the DC circuit and the chaotic circuit. According to the coupling current ratio of DC: chaotic current = 2:8, set the DC current to 0.156A and the chaotic current to 0.628A. At this time, the coupling current amplitude is 0.024A. Turn on the coupling current source, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0078] Comparative Example 1:

[0079] 1) Only the DC circuit supplies power to the manganese electrolysis system;

[0080] 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, the anode material of the electrode in the electrolytic cell is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (total current 0.78A), adjust the DC current and set the DC current to 0.78A; turn on the power supply of the DC circuit, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0081] Comparative Example 2:

[0082] 1) Only the chaotic circuit supplies power to the manganese electrolysis system;

[0083] 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, the electrode is placed in the electrolytic cell, the anode material of the electrode is quaternary alloy, and the cathode material is stainless steel; according to the current density of 350A / m 2 (total current 0.78A), adjust the chaotic current, set the chaotic current to 0.78A, at this time the current amplitude is 0.036A; turn on the power of the chaotic circuit, electrolyze the manganese sulfate solution, and precipitate elemental metallic manganese at the cathode.

[0084] Results and comparative analysis

[0085] The difference in the mass of the dry electrode before and after electrolysis was used to obtain the weight of the manganese deposited on the cathode and the mass of the anode mud. The electrode voltage U during the electrolysis process was collected, and the current efficiency CE was calculated according to formula (1). The electrolysis energy consumption EC was calculated according to formula (2), where q is the electrochemical equivalent of metallic manganese. The current efficiency and electrolysis energy consumption are used to evaluate the electrolysis performance and energy consumption during the electrolysis of manganese. Under the same conditions, the electrolysis experiment was carried out, and a coupled current source was used as the manganese electrolysis power supply to output nonlinear currents of different currents. The current efficiency CE, electrolysis energy consumption EC, and the amount of anode mud generated are shown in Table 1. Under the single DC electrolysis of Comparative Example 1, the current efficiency was 82.29%; under the single chaotic electrolysis of Comparative Example 2, the current efficiency was 83.25%. As can be seen from Table 1, after coupling the DC and chaotic currents, the coupled currents at any ratio achieved better electrolysis results. For example, when the DC: chaotic current ratio is 8:2, the current efficiency is 84.20%, which is 1.91% higher than that of DC; when the DC: chaotic current ratio is 2:8, the current efficiency is 85.55%, which is 3.26% higher than that of DC; and the best electrolysis effect is obtained when the coupling current ratio is DC: chaotic current = 4:6, the current efficiency is 4.25% higher than that of DC, the electrolysis energy consumption is 5.08% lower than that of DC, and the anode mud is reduced by 27.99%, which has the most efficient energy saving effect. The electrolysis products are analyzed ( Figure 3 This is the microscopic morphology of cathode manganese deposition. Figure 4 The microscopic morphology of anode mud, where (a) represents DC electrolysis, (b) represents DC: chaotic current = 4:6 coupled current electrolysis, and (c) represents chaotic current electrolysis). Figure 3 As shown in (a), under direct current electrolysis, the surface of the cathode manganese deposit is uneven and the manganese dendrite particles are densely distributed. With the introduction of chaotic current, the cathode interface concentration polarization is improved and the cathode fractal growth is suppressed, and the resulting manganese coating is smoother and denser ( Figure 3 (b)). Figure 4 As shown, compared to direct current electrolysis, coupled current produces denser anode mud deposits, enhanced anode corrosion resistance, and suppressed anode contamination. Coupled current not only regulates cathode dendrite growth and anode mud using chaotic current, but also improves energy efficiency and the manganese electrolysis process, enabling efficient production and clean electrolysis. This approach holds great promise for application in hydrometallurgy.

[0086] CE=m / (q·I·t) (1)

[0087] EC = U·1000 / (q·CE) (2)

[0088] Table 1 Electrolysis parameters and effects of different current types

[0089]

[0090] 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 coupled current electrolytic method for manganese electrodeposition, characterized in that: The following steps are involved: (1) Adding a manganese sulfate solution system to the electrolytic cell; (2) Turn on the coupled current source for electrolysis; The coupling current source includes a DC circuit and a chaotic circuit, the anode of the DC circuit and the anode of the chaotic circuit are connected to the anode of the electrolytic cell, and the cathode of the DC circuit and the cathode of the chaotic circuit are connected to the cathode of the electrolytic cell; the coupling current source is turned on by turning on the power switch of the DC circuit and the power switch of the chaotic circuit; The current ratio of the DC circuit to the chaotic circuit is 2:8 to 8:

2.

2. The method according to claim 1, wherein 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 average current density of the coupled current source in step (2) is 350 A / m 2 .

3. The method according to claim 1, wherein The magnitudes of the currents of the DC circuit and the chaotic circuit can both be adjusted.

4. The method according to claim 1, wherein The current ratio of the DC circuit to the chaotic circuit is 4:

6.

5. The method according to any one of claims 1 to 4, characterized in that: The anode material of the electrode of the electrolytic cell is a quaternary alloy, and the cathode material is stainless steel.

6. The method according to any one of claims 1 to 4, wherein: The electrolyte temperature in the electrolytic cell is 40°C.

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