FILTER PRESS DEVICE FOR ELECTRODEPOSITION OF METAL FROM SOLUTIONS, WHICH IS MADE UP OF SEPARATING ELEMENTS CONFORMED BY ION EXCHANGE MEMBRANES FORMING A PLURALITY OF ANOLYTE AND CATHOLYTE CHAMBERS, WHEREIN THE ELECTRODES ARE CONNECTED IN SERIES WITH AUTOMATIC DETACHMENT OF THE METAL PRODUCT

Abstract

A filter press device for electrolytic production of metal for electrodeposition of metal from solutions, constructed from a plurality of cells connected electrically and hydraulically in series. Each has alternating frames and ion-exchange membranes to form alternating anode and cathode compartments, allowing the free path of liquid. Anolyte or catholyte passes through each compartment. The electrolyzed product is discharged from the compartment in the form of metal or a metallic compound. The electrodes are designed with a vertical base plate acting as an anode with the respective anolyte in a cell unit and in the other, acting as a cathode with the respective catholyte in the adjacent cell unit. Completed the production cycle, the device is stopped, the cell is opened, allowing the metal deposition electrodes, cathodes, can be removed and replaced to start a new productive cycle or remain in place with automatic detachment of metal product.

Claims

1. A filter press device for the electrodeposition of metal from solutions that contain it, wherein it is a completely closed and pressure sealed device-, with no emission of gases, under controlled conditions of pressure, flow, amperage, voltage, pH, and temperature, consisting of chamber units that operate independently formed by a series of plates made of an electrically insulating material, electrodes, and ion exchange membranes placed between each anode and cathode to form a plurality of anode and cathode compartments, wherein each one of the plates of insulating material contains a series of openings from which the electrolytes and liquors from metallurgical operations are loaded into the cathode and anode compartments at room temperature, respectively, flowing at uniform high flow rates and short residence times and high amperage, wherein each compartment comprises independent communication openings for the movement of the catholyte or the anolyte, which are arranged along the length of the electrowinning device in parallel and/or series, at the same time allowing the incorporation and movement of the fluids inside each compartment, from one end to the other, from the lower part to the upper part, upper part to lower part, from left to right, or vice-versa, and from opposite positions to their incorporation, the spent liquors are removed, wherein, once the production cycle has concluded, the cell is stopped, by opening thereof, the metal deposition cathodes can be raised to remove them from their place, and replace them to start a new production cycle, or remain in place with the detachment of the electrodeposited product without the need to remove the cathode from the device due to the low roughness present in the cathode base metal.

2. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein, in industrial production, the electrodeposition devices are electrically connected in series, wherein all of the electrodes, except the terminal electrodes are bipolar, are equipped with a vertical plate base separated by a rubber piece, and wherein one side acts as an anode in a cell unit, while in the other side acts as a cathode in the adjacent chamber unit.

3. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the device is made up of chamber units that operate hydraulically in parallel or in series, at flow rates between 1 and 100,000 l/min.

4. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein all of the electrodes are designed with a vertical base plate, with a single compact body of metal plates of different nature if they are cathodes or anodes connected in series in which the terminal electrodes have electrical connections for the row of devices.

5. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the metal cathode with the product of the electrolysis is removed in cyclical production periods dependent of the concentration of metal dissolved in the catholyte without cathode extraction with detachment in the device due to the low surface roughness of this.

6. The filter press device for the electrodeposition of metal from impregnated solutions according to claim 1, wherein the metal support cathode does not suffer corrosion due to pitting in the metal.

7. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein, in the terminal plate made of a seal insulating material of the device, there are at least a pair of openings which together form a compartment of the cell, and which serve as a hydraulic compensation collector for the catholyte and anolyte fluids, respectively.

8. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the plates of electrically insulating material have thicknesses that range between 1 to 100 mm.

9. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the cathode plates are made of stainless steel, titanium, or another steel alloy, and the anode plates are made of lead alloy, lead, or titanium or another metal, and their thicknesses in both cases range between 1 to 5 mm.

10. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the area of the ion exchange membrane separating the catholyte and anolyte is approximately equivalent to the metal deposition area, being encapsulated between meshes of electrically insulating material.

11. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the area of the device is defined according to the area of metal to be deposited on the cathode, a variable surface area that is designed according to industrial requirements: 0.10-2 m.sup.2.

12. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the current supplied to the device allows current densities between 50-2000 A/m.sup.2 to be achieved.

13. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the temperature of the catholyte and anolyte solutions ranges between 10-60 C.

14. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the device can be applied to any liquor or solution containing dissolved metals, among these, copper, zinc, gold, silver, cadmium, nickel, cobalt, uranium, iron, among others, with contents ranging between 0.5 to 50 g/l.

15. The filter press device for the electrodeposition of metal from solutions that contain it according to claim 1, wherein the device reduces the times of the chemical reactions and the residence of the electrolytic solutions in the device, leading to homogeneous electrodepositions, which makes it possible to select the size of the material to be deposited and the thickness of the metal plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG. 1 is a schematic exploded view that shows an arrangement of the chamber frames, the electrodes between the chamber frames, the ion exchange membrane, the membrane support, and the transfer openings for the electrolyte and liquor in a filter press apparatus of an electrowinning device interpreted according to the present invention.

[0051] FIGS. 2, 3 and 4 are cross-section views of a chamber frame of the electrowinning device comprising the electrolyte circulation openings and the assembly condition elements according to the present invention.

[0052] FIGS. 5, 6, 7, 8, 9 and 10 are cross-section views of a chamber frame comprising its front and rear view, and the support structure grate of the ion exchange membrane according to the invention.

[0053] FIGS. 11, 12, 13, 14 and 15 are cross-section views of the terminal frame of the electrowinning device.

[0054] FIG. 16 is a cross-section view of the electrode of the electrowinning device, in its configuration as a cathode.

[0055] FIG. 17 is a cross-section view of the electrode of the electrowinning device, in its configuration as an anode.

[0056] FIG. 18 is a cross-section view of the rubber sheet of the electrowinning device, in its configuration as an insulator and separator of the anode and cathode electrodes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] In reference to FIG. 1 of the electrowinning device, the cathode comprises a plate (1) that totally covers the central opening and is the active surface of the cathode, which is the space (2) through whose frame (3) the catholyte circulates. Adjacent to this frame (3) is the frame (4), which is arranged in line on a plane parallel to that of the plate (1). Inside this frame (4), in the space corresponding to the central opening (2), it contains an ion exchange membrane (5), which is supported on both sides by grates (6) and prevents the transfer of fluid from the circulation space of the anolyte corresponding to the frame (7), open space (2) totally covered by the active surface of the electrode wall (8) in contact with the anolyte acting as an anode that seals the opening through which the anolyte flows. The opposite wall of the electrode is covered with an insulating rubber piece (21) that separates it from the cathode (1), allowing the reconfiguration of the electrowinning device in the same way as explained before, to configure two identical chambers and the electrowinning device made up of equivalent chambers according to the present invention.

[0058] The frames (3), (4) and (7) have eight openings (9), (10), (11), (12), (13), (14), (15) and (16) which in the electrowinning device, along its length, form an internally connected whole, connected to the headers through which the electrolyte is loaded into the catholyte circuit, and liquor is loaded into the anolyte circuit, which flow to the cathode and anode compartments, respectively, filling each chamber of the electrowinning device with fluid. The anolyte compartments are entered through the lateral openings (12) and (13), while the product of the electrolysis is extracted through the lateral openings (9) and (15). Similarly, and in the same way and in parallel, the catholyte fluid enters through the openings (14) and (16) and is extracted through the openings (10) and (11). The cathode plate (1) and anode plate (8) are constructed such that they do not interfere with the circulation flows of the intake and outlet liquors in and out of the device and in the case of the ends of the electrowinning device, both electrodes (1) and (8) have openings for the connection to electrical energy. As a product of the electrolysis, metal is generated and deposited on the cathodes (1) of the device. At the end of the production cycle, when the expected thickness of metal on the cathode (1) and a minimum concentration of metal dissolved in the electrolyte have been achieved, the device is opened and the cathodes are lifted out and extracted. They are then replaced to start a new production cycle. In the cases that require it, the metal can be removed by simply allowing it to fall directly to the base of the device for collection and transport. The common guide (17) of the frames, secures them to a rail and their pressing, when applicable, is the equivalent of a filter press. This way, the guide (17) allows the movement of the frames (3), (4) and (7) in the enclosure and the opening of the electrowinning device, according to the invention.

[0059] The space between the surface of the cathode (1) and the surface of the ion exchange membrane (5), and between these and the surface of the anode (8) varies between 1-50 mm, while the feed rate of the electrolytic solution varies between 1-2000 I/min. The electrolytic device is constructed of PVC, PP, or another plastic material resistant to acidic, basic, or neutral and electrically neutral solutions.

[0060] In reference to FIGS. 2, 3 and 4, these correspond to the cross-section deployment of the frame (3) in FIG. 1. In terms of construction and easy assembly of the present patent, it is possible to create the hydrodynamic flow of least resistance to the circulation of the electrolyte or liquor through the openings (9), (10), (11), (12), (13), (14), (15) and (16) with other cross-section views to the compartments of the respective chambers of the cell. Also, the openings (9), (10), (11), (12), (13), (14), (15) and (16) can be formed independently in the upper as well as the lower part, not allowing communication between the catholyte and anolyte. The guide (17) aligns the frame (3) with the other frames (4) and (7), and the others that are installed successively to form one or multiple electrowinning devices according to the invention.

[0061] In regard to FIGS. 5, 6, 7, 8, 9 and 10, these are cross-section views of the standard frame (4) corresponding to the pieces that make up its parts for easy assembly and construction wherein FIG. 5 is the front side of the first section and FIG. 6 is the back side of the first section. Each slot or opening of a surface has its correspondence on the other surface, (10), (11), (14) and (16). Similarly, in FIGS. 7 and 8 which make up the second section, each projected part has its correspondence on each side of the surface, (9), (15), (12) and (13). From the point of view of the stress on the frame, this form of construction is preferable because of its easy construction and assembly, and because it keeps the opening (2) constant in the electrolytic compartment. The inside of the frame (4) contains the ion exchange membrane which, due to its flexibility and long estimated period of use, must be stiffened, because it separates the catholyte and anolyte compartments. FIG. 9 shows the support grate (6) that is shown in FIG. 10, and it is structured and formed of squares, constructed of the same material as the device, which gives it a high degree of strength and allows for easy installation.

[0062] In reference to FIGS. 11, 12, 13, 14 and 15, these correspond to the terminal frame of the electrowinning device, showing the hydrodynamic sections for carrying the fluids in the device, for both easy construction and installation. In the first cross-section, FIG. 11, the active intake conduit openings (10) and (11), which correspondingly have their outlet at the opening (18), as shown in the cross-section in FIG. 12. Similarly, the active intake conduit openings (12) and (13), have their outlet (19) as shown in FIG. 11. They then continue through FIGS. 13 and 14. FIG. 15 is the sealing cover (20) of the electrowinning device according to the invention.

[0063] In reference to FIG. 16, the cathode (1), typically made of stainless steel, titanium, iron alloys, or another suitable material for the catholyte compartment according to the present invention.

[0064] In reference to FIG. 17, the anode (8), typically made of lead, tin, calcium, or another required material depending on the anolyte liquor according to the present invention.

[0065] In reference to FIG. 18, the rubber sheet (21) typically Eva rubber, India rubber, or another suitable material to insulate and separate the anode (8) and cathode (1) electrodes in the electrowinning device according to the invention.

Exemplary Embodiments

[0066] The following sections will describe the present invention in greater detail in regard to several working examples, which nevertheless shall not limit the scope of the invention.

[0067] Electrolytic copper was produced using the electrowinning device described in the present invention FIG. 1. The filter press metal electrowinning device was assembled according to the description in the present invention, with a size in reference to what is industrially required to obtain copper m.sup.2, and that define the examples that are described:

[0068] 1. In the corresponding frames, position a flat cathode (1) and a flat anode electrode (8), made of stainless steel in the case of the cathode and lead in the case of the anode, respectively, measuring 250 mm250 mm each, with the cathode and anode arranged face to face.

[0069] 2. Both electrodes separated by an ion exchange membrane, with a pass-through thickness defined for circulation of the catholyte that is from the cathode to the membrane, of 40 mm; and for the circulation of the anolyte, that is from the anode to the membrane, of 10 mm.

[0070] 3. The pressure required for rapid assembly of the elements varied between 3-5 kg/cm.sup.2, with this pressure applied by the press until there were no signs of leaks of the solution from the device.

[0071] 4. The electrolytic solutions are carried to the electrowinning device through plastic pipes, as is also the case of the storage tanks and receivers of the circulating liquid.

[0072] 5. The anolyte solution circulates through the compartments and ducts arranged for this purpose, according to the invention at 600 l/min, while the catholyte solution circulates through its respective compartments also at 600 l/min.

[0073] 6. In usage, a DC (direct current) electrical power supply is connected to the electrowinning device with its positive terminal connected to the electrode (8) that is the anode, and its negative terminal to the cathode (1) metal, preferably with easy to install clip-on connectors.

[0074] With the application of direct current between the cathode and the anode and the acidified copper sulfate solution, 99.99% Cu electrolytic copper was obtained under the conditions indicated in Table I.

TABLE-US-00001 TABLE I Operational data EW filter press device Example No. 1 2 Concentration Cu (g/l) 5 5 Electrolyte flow (l/min) 600 600 Cell voltage (V) 12.8 12.0 Catholyte temperature ( C.) 42.5 41.0 Catholyte pH 1.46 1.34 Current density (A/m.sup.2) 192 192 Operation time (h) 8 24 Cathode weight (3) (g) 292.8 853.7 Efficiency (%) 97 96