TW201606139A - Cell for metal electrowinning - Google Patents

Abstract

The present invention relates to an electrolyser for electrowinning of non-ferrous metals comprising a plurality of intercalated elementary cells, wherein each elementary cell is equipped with a device suitable for the detection of anomalies in the distribution of electric current to the respective anode.

Description

A unit cell of a metal electrorefining cell and an anode element thereof, and an electrolytic cell for initially extracting metal from an electrolytic bath, and a method for obtaining copper from a solution containing cuprous ions and/or copper ions

The present invention relates to an electrolysis cell comprising a plurality of unit cells suitable for metal electrosynthesis, especially from an ionic solution, electrolytically producing copper and other non-ferrous metals, and an electrowinning plant for performing such electrospinning.

Electrochemical plants for the electroplating of non-ferrous metals, such as electrolytic extraction and refineries, also known as electrorefining plants and electric refineries, typically use at least one electrolytic cell, including a plurality of unit cells, each consisting of an anode and a cathode.

In the electrolytic cell intended for use in the above-mentioned plants, the anode and the cathode are generally placed in the discharge bath, in alternate positions and parallel to each other. The electrodes are mechanically and electrically connected to the boom and the boom is brought into contact with the busbar for feeding. In the electrolytic cell, the same busbar is shared between electrodes of the same polarity and connected in parallel with each other.

For example, in the production of non-ferrous metals such as copper, cobalt, zinc or nickel, the metal generated by the electrochemical reaction is deposited at the cathode of each unit cell when the current is passed, and is harvested at regular intervals (usually several days). The cathode is extracted from individual electrolytic cells. The deposition of metal on the cathode occurs in a non-uniform manner, causing localized deposition, also known as dendritic or dendritic crystal formation, which develops at an increasing rate towards the anode under the effect of current flow, causing an electrical short. In this case, the temperature of the anode rises, which is equivalent to the damage caused by the formation of dendrites, and the formation of dendrites may locally weld to the surface of the anode, hindering the metal harvesting operation.

The above-mentioned general problems concerning the formation of dendrites, especially related to the anode of modern concept, are made of titanium mesh or mesh sheet, and are provided with catalytic material coating, which is more effective than the conventional lead anode because the short circuit condition is expensive and impossible. Repair the damage. These problems can also be confirmed by the further anode type contained in the patent application WO2013060786, in which a titanium mesh coated with a catalytic material is inserted into a transparent material, such as a porous polymer insulation material or an ion exchange membrane, which is formed in the outer layer. side. Anode damage implies a consistently high factory maintenance cost, and lower metal parts may be further damaged, and associated plants may be forced to stop working.

Therefore, in the form of growth of dendritic crystals, it is urgent to provide a form of unit cell anode for protecting the electrolytic cell, and it is also necessary to immediately identify and report individual anodes or individual electrolytic cell anodes, in which one or more dendritic crystals grow to form a potential threat. . Because the above-mentioned factories are an environment that is harmful to health, because of the high temperature and possible acid mist in the vicinity of the electrolytic cell, the detection and especially the individual anodes that are affected by the formation of dendrites are also used, and the purpose is to allow the factory maintenance personnel to quickly Intervene to reduce the residence time in the cell.

The gist of the present invention is intended to be within the scope of the accompanying claims.

A gist of the invention relates to a metal electrorefining cell comprising a plurality of unit cells, each cell comprising an anode and a cathode, the anode being provided with a catalytic surface facing the oxygen release reaction, the cathode being adapted to deposit metal from the electrolytic bath, and a porous mesh, Interposed between the anode and the cathode. The battery, in turn, includes a conductive anode boom electrically and mechanically coupled to the anode, and a conductive cathode hanger electrically and mechanically coupled to the cathode. Each unit cell also includes means adapted to directly or indirectly detect current flow through the corresponding anode boom. The cell is also equipped with an anode busbar electrically connected to the anode boom of each cell, and a cathode busbar electrically connected to the cathode boom of each cell. The electrolysis cell also includes a cathode balance bar arranged in parallel and adjacent to the anode bus bar.

The porous mesh (which is electrically conductive as appropriate) is interposed between the anode and the cathode of the unit cell, and its structure can be made to a different degree of tightness, and is made to allow the passage of the electrolytic solution without interfering with ion conduction between the anode and the cathode.

Electrolysis is carried out in the above-described electrolytic cell design, and the dendrites which may be formed in one or more cathodes of the unit cell are contacted to face the porous mesh before reaching the back of the anode surface, so that their growth is stopped or slowed down under any circumstances. It has been observed that when the formation of dendrites is in contact with the porous web, even if a very small conductivity is exhibited, a part of the metal formed in the battery is directly deposited on the net and coated. In this case, the assembly of the cathode, the dendrites, and the porous mesh, because of the electrical connection between the components, is additionally functioning as a new cathode of the unit cell located closer to the anode than the original configuration. In this case, the lower resistance drop in the electrolyte associated with the reduced gap between the new cathode and anode causes an increase in current flow through the corresponding anode boom. This degree of current increase is known to indicate the growth of dendrites.

In a specific example, the current flowing into each of the anode booms can be directly or indirectly detected, and the voltage or temperature variation can be measured by the detecting device by the boom itself or the component electrically connected thereto.

In one embodiment, the measurement of the voltage variation is coupled to the associated anode busbar by means of a detection device, and to the cathode boom by electrically conductive and optionally flexible pressure contacts. The advantage of this configuration is that it avoids the fixed electrical connection to the anode boom and finally makes the battery maintenance easier.

In another embodiment, the measurement of the voltage variation is performed by connecting the detecting device to a corresponding anode boom through two points located at a certain distance along its major axis.

In a specific example, the temperature variation measurement can be performed using a heat sensitive device such as a thermocouple. This measurement can be carried out, for example, with a heat sensitive device on each of the anode booms, preferably at the end, or additionally on the anode busbar corresponding to the contacts of the anode boom. The heat sensitive unit can be fitted with a chemical resistant lining to protect and/or enhance the insulation from the surrounding environment.

In another embodiment, the measurement of the temperature variation may be by a temperature-chromic paint and may change color when the temperature exceeds a predetermined threshold. This lacquer can be applied to the anode boom or to the anode busbar of the anode boom contact. The advantage of this specific example is that the potential critical condition determined by the growth of the dendrites can be seen immediately by the staff in the electro-chemical plant and quickly identify the cell in which the condition occurs, as well as the anode or cathode in the cell.

In a specific example, each detecting device can be connected to its own microprocessor to form a measurement and a predetermined reference range obtained by the comparing device; if the measurement is not within the reference range, the microprocessor can actuate the signaling system, either sequentially or simultaneously Acting more messaging systems. The microprocessor and/or signaling system can be turned off during the cathode picking operation. The microprocessor can be integrated into the single unit with the signaling system and/or the detection device.

In one embodiment, the microprocessor is powered by the process voltage, avoiding the use of battery packs that require periodic replacement operations. In particular, the microprocessor can be directly connected to the anode bus bar and the cathode balance bar if the cell is installed. If the cell does not contain a cathode balance bar and you want to avoid fixing the wiring to avoid interference with plant operation, the microprocessor for monitoring an anode boom is connected to the anode bus via a preferably flexible pressure contact. And the hanger of the adjacent cathode.

In one embodiment, the microprocessor operates at least one of the signaling systems, including the light emitting diodes, that can be coupled to the fiber, either directly or through an optical coupling device. Fiber optics can be seen Polymer material, allowing the transmission of optical signals to the end of each anode boom, or better to the outside of the cell, to facilitate identification by the plant operator, to quickly identify the cell, and the cell anode, or to present direct or indirect current values at predetermined times Anodes outside the range of values.

In one embodiment, the porous mesh can be made from a carbon fabric of suitable thickness. In another embodiment, a porous mesh made of a corrosion resistant metal, such as titanium, may be comprised of a mesh or perforated sheet having a coating that is catalytically inert to the oxygen release reaction. In one embodiment, the catalytically inert coating can be based on tin, ruthenium, osmium or titanium, such as an oxide. In one embodiment, the anode is formed from a titanium mesh or a stretched sheet coated with a catalytic material. In still another embodiment, the titanium mesh coated with the catalyst is inserted into the inner side of the outer layer composed of the permeable separator, such as a polymer porous sheet or an anion separator, fixed to the frame, and covered with a dehumidifier.

The gap between the best porous mesh and the anode surface depends on the process characteristics and the overall size of the plant. In the factory used to demonstrate the invention, the best benefit is that the battery is separated by an anode and a cathode by 25-100 mm, and the porous screen is spaced from the anode to the side by 1-20 mm.

Another object of the present invention relates to an anode element for a unit cell of an electrolytic cell for metal electrosynthesis, comprising an anode having a catalytic surface for reacting oxygen, a porous mesh, an anode hanger mechanically and electrically connected to the anode, and A device that directly or indirectly detects the current flowing through the anode boom. A device suitable for directly or indirectly detecting current can be manufactured as described above and can be connected to the processor as needed, adapted to compare the detected value with a predetermined range of values, and actuate one or more when the detected value is not included in the preset range Alarm signal. The alarm signal can be acoustic, visual, electromagnetic, or any other property and can be composed of a combination of complex signals.

Another aspect of the invention relates to a unit cell for a metal electrolysis cell comprising: a tantalum anode having a catalytic surface for reacting oxygen; a tantalum cathode, juxtaposed with the anode, suitable for depositing metal from an electrolytic bath; a mesh interposed between the anode and the cathode; a conductive anode hanger integrally formed with the anode and electrically connected; a crucible device adapted to directly or indirectly detect a current flowing through the anode hanger; The anode busbar is electrically conductive and electrically connected to the anode boom.

Another object of the invention is a process for obtaining copper from a solution containing cuprous and/or copper ions, comprising electrolyzing a solution in the above-described electrolytic cell.

100‧‧‧Anode

200‧‧‧ cathode

300‧‧‧Porous mesh

400‧‧‧Anode hanger

450‧‧‧cathode boom

500‧‧‧ device

600‧‧‧ Conductive anode busbar

700‧‧‧Microprocessor

800‧‧‧Send system

801‧‧‧Lighting diode

802‧‧‧Optical coupling system

803‧‧‧ fiber optic

900‧‧ ‧ staff

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a unit cell of a metal electrolysis cell according to a specific example of the present invention; and Fig. 2 is a view schematically showing a cell-forming system for growing a dendrite in a unit cell of a metal electrolysis cell according to a specific example of the present invention.

The embodiments of the present invention are described with reference to the accompanying drawings, in which FIG.

1 is a schematic view showing a unit cell of a metal electrolysis cell, comprising an anode 100, a cathode 200 arranged in parallel with the anode, suitable for depositing metal from an electrolytic bath; a porous mesh 300 interposed between the anode and the cathode; and an anode suspension Rod 400, integral with the anode and electrically connected; cathode boom 450; apparatus 500 adapted to directly or indirectly detect current flowing through anode boom 400; conductive anode busbar 600, and anode boom 400 Electrically connected. A device 500 adapted to detect current directly or indirectly can be coupled to the microprocessor 700 to form a comparison of the amount of detection of the device 500 with a predetermined range of values. The microprocessor 700 is coupled to the signaling system 800 and is activated when the detected value is outside the reference range.

Figure 2 shows device 500 adapted to detect current directly or indirectly, connected to microprocessor 700 for comparison with a predetermined range of values. The microprocessor 700 is configured to actuate the signaling system 800 when the detected supply value is outside the reference range. The signaling system 800 can be comprised of a light emitting diode 801 that emits an optical signal when actuated by the microprocessor 700. The diode 801 signal is transmitted by the optical fiber 803, and the optical fiber is coupled to the diode 801 via the optical coupling system 802 as the case may be.

The fiber is placed at a predetermined position at the extreme of the output optical signal 803, so that the employee 900 operating at the factory can easily recognize it.

The foregoing is not intended to limit the invention, and may be used in accordance with various specific examples without departing from the scope of the invention.

In the context of this specification and the scope of the patent application, the word "comprising" and its variations are not intended to exclude other components, components, or additional steps.

The documents, regulations, materials, devices, papers, etc. mentioned in this specification are purely for the purpose of providing the context of the present invention, and do not suggest or represent any part or all of such things, forming part of the prior art foundation, and The present invention is prior to the priority date of each patent application scope of the present application General knowledge in related fields.

100‧‧‧Anode

200‧‧‧ cathode

300‧‧‧Porous mesh

400‧‧‧Anode hanger

450‧‧‧cathode boom

500‧‧‧ device

600‧‧‧ Conductive anode busbar

700‧‧‧Microprocessor

800‧‧‧Send system

Claims (16)

A unit cell of a metal electrolysis cell comprises: a ruthenium anode having a catalytic surface for reacting oxygen; a ruthenium cathode disposed in parallel with the anode, suitable for depositing metal from an electrolytic bath; Between the anode and the cathode; ̇ conductive anode hanger, integral with the anode and electrically connected; ̇ device, suitable for directly or indirectly detecting the current flowing through the anode boom; ̇ anode bus bar, with conductivity Sexually and electrically connected to the anode boom. The battery of claim 1, wherein the direct or indirect detection current comprises an appraiser of the selected physical quantity between voltage and temperature. For example, the battery of claim 2, wherein the physical quantity is evaluated by using a temperature-changing paint or a heat-sensitive device to measure the temperature. The battery of claim 3, wherein the heat sensitive device is a thermocouple. The battery of claim 3, wherein the temperature measurement is performed on the anode boom adjacent to the electrical connection of the anode bus bar. A battery according to claim 3 or 4, wherein the temperature measurement is on the anode bus bar and is carried out in the vicinity of the anode hanger. The battery of claim 1, further comprising a microprocessor connected to the detecting device, and at least one transmitting system, wherein the microprocessor is configured to compare the detected current with a predetermined reference range, the at least one The system is configured to be actuated whenever the detection provides a value outside of the reference range. The battery of claim 7 includes: ̇ a conductive cathode hanger integrally formed with the cathode and electrically connected; ̇ cathode balance bar. For example, the battery of claim 8 wherein the power of the microprocessor is provided by a process voltage supplier. The battery of claim 9, wherein the power source is obtained by connecting the anode bus bar to the cathode balance bar. The battery of claim 9, wherein the power source is obtained by a pressure connected to the anode bus bar and the cathode hanger. The battery of any one of clauses 7 to 11, wherein the signaling system comprises a light emitting diode, and the microprocessor is used as an actuator. The battery of claim 12, wherein the light emitting diode system is connected to the fiber. An electrolytic cell in which a metal is mainly extracted from an electrolytic bath, including any of the batteries of the aforementioned patent claims, to electrically connect the stackers to each other. A process for obtaining copper from a solution containing cuprous and/or copper ions, comprising electrolyzing a solution in an electrolytic cell of claim 14 of the patent application. An anode component for metal electrolysis, comprising an anode, at least one catalytic surface facing an oxygen releasing reaction, at least one porous mesh, an anode hanger mechanically and electrically connected to the anode, and a device suitable for Directly or indirectly detecting the current flowing through the anode boom.