Insoluble anode plate for lead electrolytic refining and use method of insoluble anode plate

Abstract

The invention discloses an insoluble anode plate for lead electrolytic refining and a using method thereof.The insoluble anode plate comprises a composition plate and a conductive part arranged at the top of the composition plate, the conductive part and the composition plate are detachably connected through a connecting piece, and the composition plate comprises a pair of graphite plates and a titanium plate clamped between the graphite plates. The insoluble anode plate is simple in structure, the composition plate composed of the titanium plate and the graphite plate is adopted as the anode base body, the concentration of lead ions in lead electrolyte can be greatly reduced, the insoluble anode plate is not prone to deformation, the cathode and anode short circuit phenomenon in a groove in the electrolysis process can be effectively eradicated, and the service life of the anode plate is prolonged. The electrodeposition period of the insoluble anode plate is prolonged, the number of times of recycling of the insoluble anode plate is effectively increased, the unit consumption of subsequent electrolysis direct current is greatly reduced, and the direct current efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of lead electrolytic refining equipment, and in particular to an insoluble anode plate used for lead electrolytic refining and a use method thereof. Background Art

[0002] Lead electrolytic refining is to obtain pure and high-precision industrial lead and recover the associated bismuth and rare metals. In the process of lead electrolytic refining, when the current density is constant, the DC efficiency is low and the lead grade in the lead anode plate is high, the cathode lead ion precipitation rate will be lower than the lead dissolution rate in the anode plate, causing the lead ion concentration in the electrolyte to increase. As the electrolytic refining runs for a long time, the lead ion concentration in the electrolyte increases significantly. When the total fluorosilicic acid in the electrolyte is constant, as the lead ion concentration increases, the electrolyte resistivity increases, resulting in an increase in the cell voltage, and ultimately an increase in the DC power consumption.

[0003] At present, there are many studies on reducing the lead ion concentration in the electrolyte in the prior art, such as:

[0004] Patent application number CN201410511256.9 discloses a method for reducing the lead ion concentration of lead electrolyte, comprising the following steps: 1) obtaining an anode plate by vertical mold casting, and producing a cathode starting plate by a cathode film making machine; 2) spacing the newly made cathode starting plate and anode by an automatic spacing machine, and then loading them into a slot, connecting direct current, and electrolyzing for 3.5 to 4 days; 3) removing the cathode, reloading a new cathode starting plate, continuing electrolysis for 3.5 to 4 days, removing the cathode and the residual electrode, and completing an electrolysis cycle. This method uses the same process conditions, removing the cathode after 3.5 to 4 days of electrolysis, the anode remains unchanged, and reloading a new cathode to continue electrolysis for 3.5 to 4 days to complete an electrolysis cycle. This method greatly increases the labor intensity, the rate of decrease of lead ion concentration is slow, and a large number of cathode plates are consumed, resulting in an increase in the cost of lead electrolysis.

[0005] CN200610048546.X discloses a lead removal method using an inert anode electrolysis method. An electrolytic cell is selected, and a lead cathode is first installed after a short circuit, and then the lead anode is replaced with a graphite anode. The conductive rod is a copper rod, and two graphite plates are hung on each copper rod with a copper belt to fix it. After the lead cathode is installed and energized, electrolysis is carried out. After the lead removal of the system meets the requirements, the graphite anode is removed and the lead anode is reinstalled. The graphite selected for the graphite anode is carbonized graphite with conductivity. The conductive rod of the graphite anode is a copper rod, and two graphite plates are hung on each copper rod with a copper belt to fix it. After the electrolytic cell is installed, the copper belt hanging the anode is exposed to the electrolyte surface. This method uses graphite anodes to replace lead anodes for electrolytic refining. As the electrolysis time increases, the graphite gradually becomes thinner, softer and deformed, which is not only prone to short circuits between the anode and cathode in the electrolytic cell, affecting the electrolysis efficiency; but also uses pure graphite plates as anode plates, and the electrolysis time is only 2-3 days each time. After three cycles of electrolysis, it cannot be recycled, resulting in a significant increase in the cost of lead electrolysis.

[0006] In summary, there is an urgent need to provide a lead electrolytic refining anode that can both reduce the lead ion concentration in the lead electrolyte and reduce the electrolysis cost to solve the above-mentioned technical problems existing in the prior art. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an insoluble anode plate for lead electrolytic refining and a method of using the same, wherein the insoluble anode plate can not only effectively reduce the lead ion concentration in the electrolyte, but also improve the subsequent direct current efficiency and reduce the cost of lead electrolytic refining.

[0008] The technical solution adopted by the present invention to solve its technical problems is: an insoluble anode plate for lead electrolytic refining, including a combined plate and a conductive member arranged on the top of the combined plate, the conductive member and the combined plate are detachably connected through a connecting member, and the combined plate includes a pair of graphite plates and a titanium plate sandwiched between the pair of graphite plates.

[0009] The insoluble anode plate of the present invention uses a composite plate composed of a titanium plate and a graphite plate as a matrix, replacing the lead anode plate, which can effectively inhibit the dissolution of lead in the lead anode, and can also inhibit the trace dissolution of impurity elements such as Zn, Cu, Sb in the anode plate. As the electrolysis time increases, the concentration of impurity elements such as Zn, Cu, Sb in the electrolyte can be effectively reduced. During the electrolysis process, the following ion reaction equations mainly occur at the anode and cathode:

[0010] Anode: 4OH - -4e=2H2O+O2↑

[0011] Cathode: Pb 2+ +2e=Pb;

[0012] Therefore, the insoluble anode plate only undergoes oxygen evolution during the electrolysis process without lead dissolution reaction. 2+ Normal precipitation at the cathode, thereby reducing the Pb content in the electrolyte 2+ Concentration purpose.

[0013] In addition, the insoluble anode plate of the present invention can make full use of the conductivity of graphite and the inertness of titanium plate. Compared with the use of pure graphite plate as anode plate, the insoluble anode plate is not easy to deform during the electrolysis process, and can effectively prevent the short circuit phenomenon of the anode and cathode in the cell during the electrolysis process. It not only prolongs the electrolysis time and electrolysis cycle of the insoluble anode plate, so that the number of times the insoluble anode plate is recycled is effectively increased, but also greatly reduces the subsequent electrolysis DC power consumption and improves the DC power efficiency.

[0014] Furthermore, the conductive member is a copper rod, and both ends thereof extend outward to the left and right sides of the combined plate, the rod body connecting the copper rod and the combined plate is a connecting rod, and the rod body extending outward is an extension rod.

[0015] Furthermore, the connecting piece includes a copper sheet and a stainless steel plate detachably connected to the copper sheet.

[0016] Furthermore, the copper sheet wraps the outer surface of the connecting rod, and both ends of the copper sheet extend downward to the combined plate to form an extension portion, and the extension portion is connected to the inner and outer side surfaces of the combined plate.

[0017] Furthermore, the steel plate is detachably connected to the extended portion of the copper sheet.

[0018] Furthermore, screw holes are provided on the combined plate, the extension part and the steel plate, screws are provided in the screw holes, and the combined plate, the copper sheet and the copper plate are connected together through the threaded connection between the screws and the screw holes.

[0019] The present invention also provides a method for using the insoluble anode plate for lead electrolytic refining as described above, comprising the following steps:

[0020] 1) Loading the tank: loading the cathode plate and the insoluble anode plate into the electrolytic tank;

[0021] 2) Electrolytic refining: The electrolyte is placed in an electrolytic cell and connected to direct current for electrolysis;

[0022] 3) Out of the tank: Use a hanger to take out the insoluble anode plate and cathode plate, and then clean the surface of the insoluble anode plate to prevent surface corrosion products from falling off and entering the bottom of the tank and impurities from entering the electrolyte.

[0023] Furthermore, the intensity of the direct current is 10000-12000A, and the current density is 140-170A / m 2 The electrolysis time is 5 to 7 days.

[0024] Furthermore, the circulation volume of the electrolyte is 40-50 L / min, and the temperature of the electrolyte is 40-50°C.

[0025] The insoluble anode plate for lead electrolytic refining and the use method thereof of the present invention have the following beneficial effects: the insoluble anode plate of the present invention has a simple structure, and by adopting a composite plate composed of a titanium plate and a graphite plate as an anode substrate, not only can the lead ion concentration in the lead electrolyte be greatly reduced, but the insoluble anode plate is not easily deformed, and can effectively prevent the short circuit phenomenon of the anode and cathode in the cell during the electrolysis process, not only prolonging the electrolysis cycle of the insoluble anode plate, but also effectively increasing the number of times the insoluble anode plate is recycled, and also greatly reducing the subsequent electrolysis DC power consumption, thereby improving the DC power efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 — is a schematic diagram of the structure of an insoluble anode plate for lead electrolytic refining according to the present invention;

[0027] Figure 2 -for Figure 1 Cross-section view at AA in the middle.

[0028] The above-mentioned figure marks: 1-combination plate, 2-copper rod, 3-copper sheet, 4-extension rod, 5-extension part, 6-screw hole, 7-graphite plate, 8-titanium plate. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and examples, but these specific implementation schemes do not limit the protection scope of the present invention in any way.

[0030] Example 1

[0031] See also Figure 1-2 An insoluble anode plate for lead electrolytic refining includes a composite plate 1 and a conductive member disposed on the top of the composite plate 1. The conductive member is a copper rod 2, which is detachably connected to the composite plate 1 through a connector. The copper rod 2 is used for conducting electricity during the electrolysis process. The connector includes a copper sheet 3 and a stainless steel plate (see figure). The copper sheet 3 is 1 mm thick and the stainless steel plate is 2 mm thick.

[0032] The combined plate 1 includes a pair of integrally formed graphite plates 7 and a titanium plate 8 sandwiched between the pair of graphite plates 7. The thickness of each graphite plate 7 is 10 mm, and the thickness of the titanium plate 8 is 5 mm.

[0033] The insoluble anode plate of the present invention adopts a composite plate 1 composed of a titanium plate 8 and a graphite plate 7 as a substrate to replace the lead anode plate. During the electrolysis process, the insoluble anode plate only undergoes oxygen evolution without lead dissolution reaction. 2+Normal precipitation at the cathode can effectively inhibit the dissolution of lead in the lead anode, and can also inhibit the trace dissolution of impurity elements such as Zn, Cu, Sb in the anode plate. As the electrolysis time increases, the concentration of impurity elements such as Pb, Zn, Cu, Sb in the electrolyte can be effectively reduced.

[0034] When pure graphite plate 7 is used as the insoluble anode, as the electrolysis time increases, the graphite gradually becomes thinner, softer and deformed, and can no longer be used after three cycles of electrolysis, resulting in a significant increase in production costs. In order to solve this problem, the insoluble anode plate composed of a graphite plate 7 and a titanium plate 8 is used in this embodiment, which can increase the specific gravity of the insoluble anode, and the insoluble anode is not easy to be misplaced during the electrolytic refining process. At the same time, the conductivity of graphite and the inertia of the titanium plate 8 are fully utilized, and the insoluble anode is not easy to deform during the electrolysis process, which can effectively prevent the short circuit phenomenon of the positive and negative electrodes in the tank during the electrolysis process, reduce the unit consumption of direct current in electrolysis, and increase the direct current efficiency; moreover, the electrolytic deposition cycle of the insoluble anode plate of the present invention is as long as 5-7 days, and the number of times of cyclic electrolysis is up to 5 times, which can greatly reduce the cost and energy consumption of lead electrolysis.

[0035] The left and right ends of the copper rod 2 extend horizontally outward along the left and right sides of the combined board 1 respectively, and the rod body connected to the combined board 1 is a connecting rod, and the rod body extending outward is an extension rod 4, and the connecting rod is connected to the extension rod 4 and is integrally formed.

[0036] The copper sheet 3 wraps the outer surface of the connecting rod, and its two ends extend downward to the combined board 1 to form an extension 5, and the extension 5 is connected to the inner and outer sides of the combined board 1, so that the connecting rod of the copper rod 2 and the top of the combined board 1 are wrapped together by the copper sheet 3. In order to further improve the tightness of the connection between the copper rod 2 and the combined board 1, a steel plate is also installed on the extension 5 of the copper sheet 3, and screw holes 6 are opened on the combined board 1, the extension 5 and the steel plate, and screws are arranged in the screw holes 6, and the combined board 1, the copper sheet 3 and the copper plate are connected by the threaded connection between the screw and the screw hole 6.

[0037] In this embodiment, the method for using the insoluble anode plate for lead electrolytic refining comprises the following steps:

[0038] 1) Tank loading: The prepared cathode plates and insoluble anode plates are spaced by an automatic spacing machine and then loaded into the electrolytic cell;

[0039] 2) Electrolytic refining: Place the electrolyte in an electrolytic cell and connect it to direct current for electrolysis; the DC current strength is 10000-12000A and the current density is 140-170A / m 2 The electrolysis time is 5 to 7 days, the electrolyte circulation volume is 40 to 50 L / min, and the electrolyte temperature is 40-50 ° C. The electrolytic cell is manually adjusted every 4 hours to avoid irregular lead crystallization on the cathode surface, which may cause short circuit in the cell and affect the electrolytic effect;

[0040] 3) Out of the tank: Use a hanger to take out the insoluble anode plate and cathode plate, and then clean the surface of the insoluble anode plate to prevent surface corrosion products from falling off and entering the bottom of the tank and impurities from entering the electrolyte, ensuring that the chemical quality of the precipitated lead is uniform, stable and controllable.

[0041] Comparative Example 1

[0042] The anode plate of this comparative example is a pure graphite anode plate.

[0043] Comparative Example 2

[0044] The difference between the anode plate of this comparative example and that of Example 1 is that the combined plate is composed of a graphite plate and a titanium plate.

[0045] Test Example 1

[0046] The present invention uses the insoluble anode plates of Example 1 and Comparative Examples 1-2 to carry out lead electrolysis experiments. In order to study the influence of the structure of the insoluble anode plate on the lead electrolysis effect when other factors remain unchanged, the electrolyte used in this test example is fixed to Pb 2+ 185.6 g / L, H + The insoluble anode plate was 122.8 g / L, the total acid was 252.33 g / L, the electrolyte circulation volume was 45 L / min, the electrolyte temperature was 45 ° C, the current intensity was 11500 A, the electrolysis time was 120 h, and the cell voltage was 2.37 V. The DC efficiency and Pb of the insoluble anode plate were determined when it was recycled for 5 times (each electrolysis was a cycle, and the 5 times corresponded to the first cycle, the second cycle, the third cycle, the fourth cycle and the fifth cycle. After each cycle, the surface of the insoluble anode plate was cleaned and then re-installed into the electrolytic cell with the cathode plate for electrolysis) 2+ The decrease in concentration, Pb 2+ The decreased concentration is Pb before electrolysis 2+ After electrolysis, Pb 2+ The difference in concentration is shown in the following table:

[0047] Table 1 DC efficiency and Pb of the insoluble anode plates of Example 1 and Comparative Examples 1-2 2+ Decrease concentration

[0048]

[0049] It can be seen from the table that as the insoluble anode electrowinning period is extended, the lead ion concentration in the electrolyte continues to decrease, and the order of the degree of decrease from high to low is Example 1> Comparative Example 2> Comparative Example 1; and as the lead ion concentration in the electrolyte decreases, the specific resistance of the electrolyte decreases, and the DC efficiency continues to increase, and the order of the degree of improvement of the DC efficiency from large to small is Example 1> Comparative Example 2> Comparative Example 1. It can be seen from the above that the method of the present invention can further improve and reduce the lead ion concentration in the electrolyte compared to the use of pure graphite or a combination of a graphite plate and a titanium plate, greatly reduce the subsequent electrolysis DC power consumption, and improve the DC efficiency.

[0050] Test Example 2

[0051] In this test example, the metal elements in the electrolytically precipitated lead were determined after the electrolysis and recycling of Example 1, Comparative Examples 1 and 2 and the conventional anode for 5 times. The conventional anode refers to the lead anode. The results are shown in Table 2:

[0052] Table 2 Content of metals in lead precipitated by electrolysis of Example 1, Comparative Examples 1, 2 and conventional anodes (%)

[0053]

[0054] As can be seen from the above table, compared with the content of each metal in conventional electrolytic lead deposition, Example 1 uses the insoluble anode plate of the present invention to replace the lead anode plate, and the total content of impurity metals in the electrolytic lead deposition is lower than that of the conventional electrolytic lead deposition, and the grade of impurity Sb in each impurity element is significantly reduced. Since the insoluble anode plate of the present invention only undergoes oxygen evolution reaction during the electrolysis process and does not introduce antimony impurity elements, the antimony element in the electrolyte gradually decreases, resulting in a decrease in the antimony grade in the cathode precipitated lead, and most of the other impurity elements do not change significantly, and the lead can be finally refined together with the conventional lead electrolytic lead deposition. The insoluble anode plate can be used to effectively reduce the lead ion concentration in the lead electrolyte without introducing other metal impurities into the lead electrolyte.

[0055] The total amount of impurity metals in the electrolytically precipitated lead in Example 1 is also lower than that in Comparative Examples 1 and 2, indicating that the insoluble anode plate composed of a pair of graphite plates and a titanium plate has a better lead electrolytic refining effect than the combination of a pure graphite plate or a graphite plate and a titanium plate, and can further reduce the content of impurity metals in the precipitated lead and improve the lead grade.

[0056] The words "upper", "lower", "left", "right", "front", "back", "vertical", "inside", "outside", etc. used in this article to describe the orientation or position are for the convenience of explanation and are based on the orientation or position relationship shown in the drawings. In the actual device, these orientations may be different due to the placement of the device. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0057] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An insoluble anode plate for lead electrolytic refining, comprising a composite plate and a conductive member arranged on the top of the composite plate, characterized in that: The conductive member is detachably connected to the combined plate via a connecting member, and the combined plate comprises a pair of graphite plates and a titanium plate sandwiched between the pair of graphite plates.

2. An insoluble anode plate for lead electrolytic refining as claimed in claim 1, characterized in that: The conductive member is a copper rod, and both ends thereof extend outwards to the left and right sides of the combined plate. The rod body connecting the copper rod and the combined plate is a connecting rod, and the rod body extending outwards is an extension rod.

3. An insoluble anode plate for lead electrolytic refining as claimed in claim 2, characterized in that: The connecting piece comprises a copper sheet and a stainless steel plate detachably connected to the copper sheet.

4. An insoluble anode plate for lead electrolytic refining as claimed in claim 3, characterized in that: The copper sheet wraps the outer surface of the connecting rod, and both ends of the connecting rod extend downward to the combined plate to form an extension portion, and the extension portion is connected to the inner and outer side surfaces of the combined plate.

5. An insoluble anode plate for lead electrolytic refining as claimed in claim 4, characterized in that: The steel plate is detachably connected to the extended portion of the copper sheet.

6. An insoluble anode plate for lead electrolytic refining as claimed in claim 4, characterized in that: The combined plate, the extension part and the steel plate are all provided with screw holes, in which screws are arranged, and the combined plate, the copper sheet and the copper plate are connected together through the threaded connection between the screws and the screw holes.

7. A method for using the insoluble anode plate for lead electrolytic refining as claimed in claims 1 to 6, characterized in that: The following steps are involved: 1) Loading the tank: loading the cathode plate and the insoluble anode plate into the electrolytic tank; 2) Electrolytic refining: Place the electrolyte in an electrolytic cell and connect it to direct current for electrolysis; 3) Out of the tank: Use a hanger to take out the insoluble anode plate and cathode plate, and then clean the surface of the insoluble anode plate to prevent surface corrosion products from falling off and entering the bottom of the tank and impurities from entering the electrolyte.

8. A method for using an insoluble anode plate for lead electrolytic refining as claimed in claim 7, characterized in that: The intensity of the direct current is 10000~12000A, and the current density is 140~170A / m 2 The electrolysis time is 5 to 7 days.

9. A method for using an insoluble anode plate for lead electrolytic refining as claimed in claim 7, characterized in that: The circulation volume of the electrolyte is 40-50 L / min, and the temperature of the electrolyte is 40-50°C.

Images