Method and device for preparing high-purity copper with rotary electrode

Abstract

The invention particularly relates to a preparation method and device of high-purity copper with a rotary electrode, and belongs to the technical field of new material preparation. The device comprises at least one electrolysis unit, and the electrolysis unit is provided with a first electrode, a rotatable second electrode and a third electrode. The first electrode and the second electrode form an electrodeposition area, and the second electrode and the third electrode form an electrolysis area. According to the method, gradient voltage is applied to three electrodes, so that copper-containing electrolyte is firstly deposited on the surface of a rotating second electrode in an electrodeposition area for the first time; and then, the second electrode rotates to the electrolysis area, deposited copper on the surface of the second electrode serves as an anode to be dissolved, and secondary electrodeposition occurs on the third electrode. The lead anode impurity pollution can be effectively avoided from the source, and the technological process is simple, efficient, low in cost and suitable for large-scale production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new material preparation, and particularly relates to a high-purity copper preparation method and device with a rotating electrode. BACKGROUND

[0002] In the field of copper metallurgy, copper electrowinning process is a key link to obtain high-purity copper, and its core principle is to make copper ions in the electrolyte deposit on the cathode surface through electrolysis, so as to obtain cathode copper product. At present, the mainstream copper electrowinning process generally uses lead or lead alloy as anode material. Although this kind of anode has excellent corrosion resistance to electrolyte and can maintain stable operation of the electrolysis process for a long period, it is still difficult to completely avoid the phenomenon of trace lead corrosion in the actual production process. This corrosion becomes the main source of lead impurities in the electrolyte, and leads to the fact that the lead content in the final copper product is usually maintained in the range of 1-2 ppm.

[0003] The lead impurities in the electrolyte will be enriched in the cathode copper during the electrolysis process, and even if the content is extremely low, it will also have a serious negative impact on the performance and value of the cathode copper. The electrical conductivity of lead is much worse than that of copper, and a small amount of lead atoms mixed into the copper lattice will destroy the periodicity of the lattice, significantly increase the electron scattering, and cause the electrical conductivity of the cathode copper to decrease significantly, which cannot meet the demand of high-end fields such as electric power and electronics for high-conductivity copper materials. In order to control the content of lead and other impurities in the electrolyte, existing copper electrowinning plants are equipped with cooling crystallization, ion exchange and other purification facilities. However, these devices not only require a large amount of additional investment in construction, but also consume a large amount of energy and reagents, increase the production and operation cost, and have limited purification effect, making it difficult to reduce the lead content in the cathode copper to below 0.1 ppm, which cannot meet the current market demand for ultra-high-purity copper. SUMMARY

[0004] In order to solve the problems in the prior art such as high lead impurity content in the cathode copper product due to lead anode corrosion, the need for a complex purification system, high production cost and the difficulty in stable production of high-purity copper, it is urgent to develop a new device and method which can effectively inhibit lead impurity pollution from the source, simplify the process flow and directly produce ultra-high-purity cathode copper. The purpose of the present application is to provide a high-purity copper preparation method and device with a rotating electrode, which connects the copper electrowinning and electrolysis processes through a rotatable electrode, realizes secondary deep purification of the cathode copper, effectively avoids lead anode impurity pollution from the source, and finally obtains ultra-high-purity copper with a lead content of less than 0.1 ppm on the third electrode.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] In a first aspect, the present invention discloses an apparatus for preparing high-purity copper with a rotating electrode, comprising an electrodeposition region (10) and an electrolysis region (20). The apparatus includes at least one electrolysis unit, the electrolysis unit comprising: a first electrode (101), a second electrode (103), a third electrode (102) and a driving mechanism, wherein the second electrode (103) is a rotatable electrode;

[0007] The first electrode (101) and the second electrode (103) form an electrowinning region (10), and the second electrode (103) and the third electrode (102) form an electrolysis region (20).

[0008] The first electrode (101) and the second electrode (103) are arranged opposite to each other to form an electrodeposition zone, in which the initial deposition from the copper-containing electrolyte is completed; the second electrode (103) and the third electrode (102) are arranged opposite to each other to form an electrolysis zone, in which the initially deposited copper is subjected to secondary electrolytic refining.

[0009] Specifically, the driving mechanism includes a roller (104) connected to the second electrode (103), which drives the second electrode (103) to rotate.

[0010] Specifically, the second electrode (103) acts as the negative electrode in the electrowinning region and the positive electrode in the electrolysis region.

[0011] Preferably, the first electrode (101) is a lead anode.

[0012] Preferably, the third electrode (102) is a titanium plate or a stainless steel plate.

[0013] Preferably, the second electrode (103) is made of a conductive material and can rotate about its own axis, preferably a stainless steel rod or a titanium rod.

[0014] The device of the present invention further includes an electrolytic liquid inlet (105) and an electrolytic liquid outlet (106). After the electrolytic liquid enters the electrolysis unit through the electrolytic liquid inlet (105), it first flows through the electrolytic zone, then through the electrolysis zone, and finally is discharged from the electrolytic liquid outlet (106).

[0015] In some embodiments, the device consists of multiple electrolysis units connected in series or in parallel.

[0016] Secondly, this invention discloses a method for preparing high-purity copper using the above-mentioned apparatus, comprising the following steps:

[0017] (1) The copper-containing electrolyte is introduced into the electrolysis unit through the electrolyte inlet (105);

[0018] (2) Apply a preset voltage to make the first electrode (101) have the highest potential, the second electrode (103) has the next highest potential, and the third electrode (102) has the lowest potential, thereby forming an electrowinning region and an electrolysis region;

[0019] (3) Start the roller (104) to drive the second electrode (103) to rotate. In the electrodeposition region, copper ions are deposited on the surface of the second electrode (103); then, the second electrode (103) with deposited copper is rotated into the electrolysis region, where the deposited copper dissolves as the anode, and the copper ions are deposited again on the third electrode (102) to achieve secondary purification;

[0020] (4) Collect the final high-purity cathode copper from the surface of the third electrode (102).

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) Extremely high purity: Through the unique “electrowinning-electrolysis” secondary refining process, impurities such as lead can be effectively separated, and the lead content of cathode copper products can be stably reduced to below 0.1 ppm.

[0023] (2) The present invention cleverly utilizes a rotatable second electrode as a transition, so that the final product is deposited on an inert third electrode, thus completely avoiding direct contamination of the cathode product by the lead anode.

[0024] (3) The present invention greatly simplifies the complex electrolyte purification system required in traditional processes, and reduces initial investment and long-term operating costs.

[0025] (4) The design of the rotating electrode enables the continuous and automatic operation of the electrowinning and electrolysis processes, which improves production efficiency and is easy to scale up. Attached Figure Description

[0026] Figure 1 This invention relates to an apparatus for preparing high-purity copper with a rotating electrode.

[0027] The following labels are used in the attached diagram: 10-copper electrowinning zone, 20-copper electrolysis zone, 101-first electrode, 102-third electrode, 103-second electrode, 104-roller, 105-electrolyte inlet, 106-electrolyte outlet. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] Example 1

[0030] The apparatus configuration employs a single electrolysis unit. The first electrode (101) is a Pb-Ca-Sn alloy anode plate; the second electrode (103) is a smooth titanium rod with a diameter of 50 mm, driven to rotate by rollers (104) at both ends, with the rotation speed controlled at 5 rpm; the third electrode (102) is a 316L stainless steel plate. The electrolytic cell is equipped with an electrolytic electrolyte inlet (105) and an electrolytic electrolyte outlet (106).

[0031] Electrolyte: Copper sulfate solution is used, with Cu²⁺ concentration of 45 g / L, H₂SO₄ concentration of 180 g / L, and temperature of 55℃.

[0032] Voltage control: The potential of each electrode is controlled by a DC power supply: +0.60 V is applied to the first electrode (101) (relative to the reference electrode), +0.30 V is applied to the second electrode (103), and 0 V is applied to the third electrode (102) (as cathode ground).

[0033] Preparation method:

[0034] (1) The electrolyte is pumped into the electrodeposition inlet (105) at a certain flow rate and flows through the electrodeposition region (10) between the first electrode and the second electrode. In the electrodeposition region, copper ions are reduced on the surface of the second electrode (titanium rod) to form a dense copper deposition layer.

[0035] (2) The roller (104) drives the titanium rod with copper deposited to rotate slowly and transfer it into the electrolysis zone (20) between the second electrode and the third electrode. In the electrolysis zone, the copper layer on the titanium rod is oxidized and dissolved into Cu²⁺ as the anode. These newly dissolved Cu²⁺ are then re-deposited on the surface of the third electrode (stainless steel plate) to obtain high-purity cathode copper.

[0036] (3) Waste electrolyte flows out from the electrolyte outlet (106) and can be returned to the front-end process for copper replenishment and recycling.

[0037] According to ICP-MS (Inductively Coupled Plasma Mass Spectrometry), the lead (Pb) content in the high-purity cathode copper product obtained in this way is less than 0.08 ppm, and the contents of other impurity elements such as iron, nickel, and arsenic are also better than the high-purity copper standard (ASTM B115-00), and the conductivity is significantly improved.

[0038] Example 2

[0039] Compared to Example 1, the apparatus was expanded to consist of three electrolysis units connected in series. The electrolyte flows sequentially through the three units for multi-stage purification. The lead content in the final product can be further reduced to below 0.05 ppm, demonstrating the potential of this apparatus for the production of ultra-high-end copper materials.

[0040] In summary, this invention provides a novel solution for the efficient, economical, and stable production of ultra-high purity copper.

Claims

1. An apparatus for producing high purity copper with a rotating electrode, characterized by, The application relates to a device for electrolysis and electrodeposition of copper ions, comprising: an electrodeposition area (10) and an electrolysis area (20); the device comprises at least one electrolysis unit, and the electrolysis unit comprises a first electrode (101), a second electrode (103), a third electrode (102) and a driving mechanism, wherein the second electrode (103) is a rotatable electrode; the first electrode (101) and the second electrode (103) form the electrodeposition area (10), and the second electrode (103) and the third electrode (102) form the electrolysis area (20).

2. The apparatus of claim 1, wherein, the driving mechanism comprises a roller (104) connected with the second electrode (103), and the roller (104) drives the second electrode (103) to rotate.

3. The apparatus of claim 1, wherein, the second electrode (103) serves as a negative electrode in the electrodeposition area and serves as a positive electrode in the electrolysis area.

4. The apparatus of claim 1, wherein, the first electrode (101) is a lead anode.

5. The apparatus of claim 1, wherein, the third electrode (102) is a titanium plate or a stainless steel plate.

6. The apparatus of claim 1, wherein, the second electrode (103) is made of conductive material and can rotate around its own axis, and is preferably a stainless steel rod or a titanium rod.

7. The apparatus of claim 1, wherein, the device further comprises an electrodeposition liquid inlet (105) and an electrodeposition liquid outlet (106), and the electrodeposition liquid enters the electrolysis unit through the electrodeposition liquid inlet (105), flows through the electrodeposition area first, then flows through the electrolysis area, and finally is discharged from the electrodeposition liquid outlet (106).

8. The apparatus of claim 1, wherein, the device is composed of a plurality of the electrolysis units in series or parallel.

9. A method for producing high purity copper using the apparatus according to any one of claims 1 to 8, characterized in that, the device comprises the following steps: S1: passing copper-containing electrolyte into the electrolysis unit through the electrodeposition liquid inlet (105); S2: applying a preset voltage to the three electrodes, so that the first electrode (101) and the second electrode (103) form the electrodeposition area, and the second electrode (103) and the third electrode (102) form the electrolysis area; S3: starting the roller (104) to drive the second electrode (103) to rotate, and after copper ion deposition in the electrodeposition area, the second electrode (103) rotates into the electrolysis area to perform secondary electrolysis; S4: after electrolysis, the electrolyte is discharged from the electrodeposition liquid outlet (106), and the purified cathode copper is collected from the surface of the third electrode (102).

10. The method of claim 8, wherein, in step S2, the preset voltage satisfies that the voltage of the first electrode (101) is higher than that of the second electrode (103), and the voltage of the second electrode (103) is higher than that of the third electrode (102).

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