Electrolysis device

Abstract

An electrolysis device (S1, S2) comprises a plurality of electrode members (22, 422) in which cathodes (20, 120, 220, 320, 420) are connected to the same potential and which respectively define electrode surfaces (22a, 422a) to which electrodeposited zinc powder adheres. The plurality of electrode members (22, 422) are arranged with a prescribed gap therebetween in a width direction orthogonal to a vertical direction so that the electrode surfaces (22a, 42a) are arranged side-by-side in the width direction.

Description

Electrolysis device

[0001] The present invention relates to an electrolysis device, and particularly, in addition to the electric furnace dust generated during the melting and smelting of scrap in the electric furnace method, which is one of the steelmaking processes, primary dust or secondary dust such as blast furnace dust, blast furnace - converter dust or RHF (Rotary Heart Furnace) dust, and zinc - containing dust such as sinter of zinc concentrate is used as a raw material for the electrolysis device.

[0002] In the electric furnace method, which is one of the steelmaking processes, electric furnace dust is generated as industrial waste corresponding to about 1.5% to 2.0% of the steel production amount and containing zinc oxide components during the melting and smelting of scrap. It is said that 8 million tons of electric furnace dust are generated worldwide and 400,000 tons are generated in Japan.

[0003] Most of the iron scraps are waste buildings, waste household appliances or waste automobiles. The paint base of waste buildings, waste household appliances or waste automobiles is zinc - plated. Also, scraps contain paints, plastics, oil components, etc. Therefore, electric furnace dust contains harmful organic substances such as chlorides and dioxins in addition to heavy metals such as zinc or lead. However, on the other hand, electric furnace dust contains about 20 - 30% iron and 20 - 30% zinc. Also, crude zinc oxide such as secondary dust contains about 10% iron and about 60% zinc. Therefore, electric furnace dust, etc. is very useful as a resource.

[0004] Under such circumstances, Patent Document 1 relates to an electrolysis product collection method and an electrolysis product collection system. By leaching zinc - containing substances derived from zinc - containing dust 1 with an aqueous sodium hydroxide solution 2, an aqueous sodium hydroxide solution 3 containing zinc is obtained, and electrolysis is performed using an electrolysis device E including an anode 10, a cathode 20 made of pure magnesium or a magnesium alloy facing the anode 10, and an electrolytic bath 32 containing the aqueous sodium hydroxide solution 3 containing zinc. Inside the electrolytic bath 30, a contact member 44 is sequentially brought into contact with each of a plurality of portions of the zinc electrodeposit ings 4 obtained as electrolysis products in the electrolysis step 102 at a predetermined time interval to disclose a configuration for peeling the zinc electrodeposit ings 4 from the cathode 20.

[0005] International Publication No. 2024 / 154733

[0006] However, according to the inventor's research, the configuration disclosed in Patent Document 1 discloses a configuration for peeling off the zinc electrodeposited material 4 obtained as an electrolytic product from the cathode 20. However, the zinc electrodeposited material 4 peeled off from the cathode 20 may become relatively large aggregates of zinc peeled off material 5. In such cases, if the large aggregates of zinc peeled off material 5 reach the storage section 34 at the bottom of the electrolytic cell 30, they will block it. Therefore, in order to remove such zinc peeled off material 5 from the electrolytic cell 30, it is necessary to use some kind of tool to crush the zinc peeled off material 5 stored in the storage section 34 into smaller aggregates of zinc peeled off material 5. Furthermore, if the size of such aggregates is relatively large, there is a possibility that they may physically connect the anode 10 and the cathode 20, causing an electrical short circuit. In detail, according to the inventors' studies, the electrodeposited powder, which is the zinc electrodeposited material produced in the electrolytic cell 30, has a strong tendency to form aggregates. Furthermore, when electrodeposited on the electrodeposition surface of the cathode 20, adjacent powder particles exhibit weak bonds. This also contributes to the tendency of such electrodeposited powder to form aggregates. For this reason, it is desirable that the zinc exfoliated material 5 obtained by peeling off the zinc electrodeposited material 4 obtained as an electrolytic product be in the form of aggregates of an appropriate size and shape. However, even if the zinc exfoliated material 5 is crushed with a stirrer or the like to form individual particles, each of these individual particles has a certain size and therefore does not flow easily with the electrolyte. Thus, crushing the zinc exfoliated material 5 in this way was not effective in removing the zinc exfoliated material 5 from the electrolytic cell 30. Furthermore, while it was possible to crush the zinc detached material 5 to a size suitable for transport when removed from the electrolytic cell 30, in order to wash the electrolyte components of such zinc detached material 5, it was necessary to further crush the zinc detached material 5 particles, for example, about 10 mm in size, to make them easier to wash. Moreover, the crushing that could be performed within the electrolytic cell 30 itself was limited, and there were certain limitations to the freedom of development.

[0007] Furthermore, according to the inventors' research, the configuration disclosed in Patent Document 1 has a structure in which the zinc stripped material 5 is temporarily stored in a storage section 34 at the bottom of the electrolytic cell 30 and then removed to the outside of the electrolytic cell 30, and also has a structure in which the zinc stripped material 5 is transported upward outside the electrolytic cell 30. As a result, the configuration tends to be complicated, and there is room for improvement in this respect.

[0008] The present invention was made after the above considerations, and aims to provide an electrolytic device that can separate and adhere electrodeposited zinc powder to the cathode to make it easier to peel off, and that can receive and transport the peeled electrodeposited zinc powder in a simplified configuration, while also making the electrodeposited zinc powder into powder of an appropriate size.

[0009] To achieve the above objectives, the electrolytic apparatus in the first aspect of the present invention is an electrolytic apparatus for recovering electrolytically produced zinc using a sodium hydroxide aqueous solution containing a zinc-containing substance as an electrolytic bath, comprising: an electrolytic cell containing the sodium hydroxide aqueous solution; an electrode positioned relative to the electrolytic cell so as to be located in the sodium hydroxide aqueous solution and having an anode and a magnesium cathode; an application mechanism for applying at least one of an impulse and a vibration to the cathode; and, after or while the impulse and the vibration are applied to the cathode, the electrodeposited zinc powder adhering to the cathode is disposed of inside the electrolytic cell at predetermined intervals. An electrolytic apparatus comprising: a peeling mechanism having a scraper for peeling off; and a transport mechanism for recovering the electrodeposited zinc powder in a sodium hydroxide aqueous solution and transporting it to a position above the liquid level of the sodium hydroxide aqueous solution so that the electrodeposited zinc powder that has been peeled off from the cathode and fallen downward in the vertical direction of the electrolytic cell is transported to the outside of the electrolytic cell, wherein the cathode has a plurality of electrode members that are connected to the same potential and each defines an electrode surface to which the electrodeposited zinc powder adheres, and the plurality of electrode members are arranged with a predetermined gap between them in the width direction such that the electrode surfaces are arranged side by side in the width direction perpendicular to the vertical direction.

[0010] Furthermore, in addition to the first aspect of the present invention, a second aspect is that the plurality of electrode members are a plurality of electrode plates, each being a strip-shaped flat plate member, and the predetermined gap is set in a range of 1 mm to 20 mm.

[0011] Furthermore, in addition to the first or second aspect, the present invention has a third aspect in which a resin member is fitted into the predetermined gap.

[0012] Furthermore, in addition to the third aspect of the present invention, a fourth aspect is that the plurality of electrode plates face each other in directions perpendicular to the vertical direction and the width direction, and the resin member is a single member to which the plurality of electrode plates are attached so as to expose the electrode surface.

[0013] Furthermore, in addition to any of the first to third aspects, the present invention has a fifth aspect in which the conveying mechanism is a chain conveyor, and the chain conveyor has buckets for scooping up the electrodeposited zinc powder in an area corresponding to the entire area of ​​the falling region of the electrodeposited zinc powder that is stripped from the cathode and falls downward into the electrolytic cell.

[0014] Furthermore, in addition to the fifth aspect of the present invention, the chain conveyor transports the electrodeposited zinc powder to a position above the liquid level of the sodium hydroxide aqueous solution by exhibiting a transport track that extends in the vertical direction, and the bucket, when scooping up the electrodeposited zinc powder, has an opening that faces parallel to the bottom of the electrolytic cell, when the bucket rises upward, has an opening that faces upward, and after the bucket has exceeded the liquid level of the sodium hydroxide aqueous solution, has an opening that faces diagonally downward.

[0015] Furthermore, in addition to the fifth or sixth aspect of the present invention, the chain conveyor has a folded portion that folds back upward in the vertical direction from the bottom of the electrolytic cell, and the folded portion has a curved R shape with a predetermined bending radius.

[0016] Furthermore, in addition to any of the first to third aspects, the present invention has an eighth aspect in which the conveying mechanism is a belt conveyor, and the belt conveyor has a receiving portion corresponding to the entire area of ​​the fall of the electrodeposited zinc powder that is peeled off from the cathode and falls downward into the electrolytic cell.

[0017] Furthermore, in addition to the eighth aspect of the present invention, the ninth aspect is that the belt conveyor exhibits a transport track that extends in the vertical direction to transport the electrodeposited zinc powder to a position above the liquid surface of the sodium hydroxide aqueous solution, and has a bucket that suppresses the falling of the electrodeposited zinc powder.

[0018] Furthermore, in addition to the eighth or ninth aspect of the present invention, the belt conveyor has a folded portion that folds back upward in the vertical direction from the bottom of the electrolytic cell, and the folded portion has a curved R shape with a predetermined bending radius, which is a tenth aspect of the present invention.

[0019] Furthermore, in addition to the fifth or ninth aspect of the present invention, an eleventh aspect is that the bucket has a perforated structure or mesh structure that allows the sodium hydroxide aqueous solution to pass through.

[0020] Furthermore, in addition to any of the first to eleventh aspects of the present invention, a twelfth aspect of the present invention is that the conveying mechanism conveys the electrodeposited zinc powder intermittently in response to the expiration of a peeling period in which the electrodeposited zinc powder is peeled off at predetermined intervals.

[0021] Furthermore, in addition to any of the first to twelfth aspects, the present invention further comprises a crusher for crushing aggregates contained in the electrodeposited zinc powder, as a thirteenth aspect.

[0022] Furthermore, in addition to the thirteenth aspect of the present invention, a fourteenth aspect is that the invention further comprises a centrifugal separator for centrifuging the electrodeposited zinc powder that has passed through the crusher.

[0023] Furthermore, in addition to the fourteenth aspect of the present invention, a fifteenth aspect is that the electrodeposited zinc powder, from which the aqueous sodium hydroxide solution attached to the electrodeposited zinc powder has been separated by centrifugal force using the centrifugal separator, is washed with water three to six times.

[0024] Furthermore, in addition to the fifteenth aspect of the present invention, a sixteenth aspect is that the invention further comprises a press molding machine that forms a molded body from the electrodeposited zinc powder that has passed through the centrifuge.

[0025] Furthermore, in addition to any of the first to sixteen aspects described above, the present invention has a seventeenth aspect in which the atmosphere when filtering the electrodeposited zinc powder from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder that has been transported outside the electrolytic cell, and the atmosphere when washing the electrodeposited zinc powder separated by filtering from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder that has been transported outside the electrolytic cell, is an inert gas atmosphere.

[0026] Furthermore, in addition to any of the first to seventeen aspects of the present invention, an eighteenth aspect is that the electrolytic cell, the application mechanism, the peeling mechanism, and the transport mechanism are made of resin or ceramics.

[0027] Furthermore, in addition to the first aspect of the present invention, a 19th aspect is that each of the plurality of electrode members is a rod-shaped member, and the predetermined gap is set in the range of 1 mm to 20 mm.

[0028] Furthermore, in addition to any of the first to 19 aspects of the present invention, a 20th aspect is that the downward ends of the plurality of electrode members are held by a holding member.

[0029] According to the electrolytic apparatus in the first aspect of the present invention, an electrolytic apparatus for recovering electrolytically produced zinc using a sodium hydroxide aqueous solution containing a zinc-containing substance as an electrolytic bath, comprising: an electrolytic cell containing the sodium hydroxide aqueous solution; electrodes positioned relative to the electrolytic cell so as to be located in the sodium hydroxide aqueous solution and having an anode and a magnesium cathode; an application mechanism for applying at least one of an impact force and vibration to the cathode; a peeling mechanism having a scraper for peeling off the electrodeposited zinc powder adhering to the cathode at predetermined intervals inside the electrolytic cell after or while the impact force and vibration have been applied to the cathode; and the electrodeposited zinc powder being recovered in the sodium hydroxide aqueous solution and transported to a position above the liquid level of the sodium hydroxide aqueous solution so as to transport the electrodeposited zinc powder that has been peeled off from the cathode and fallen downward in the vertical direction of the electrolytic cell to the outside of the electrolytic cell. The electrolytic apparatus is equipped with a transport mechanism, and the cathode has a plurality of electrode members, each of which is connected to the same potential and defines an electrode surface to which electrodeposited zinc powder adheres. The plurality of electrode members are arranged with a predetermined gap between them in the width direction such that the electrode surfaces are arranged side by side in the width direction perpendicular to the vertical direction. This allows the electrodeposited zinc powder to adhere to the cathode in sections, making it easy to peel off, and the peeled electrodeposited zinc powder to be in powder form of an appropriate size. Furthermore, it is possible to receive and transport the peeled electrodeposited zinc powder with a simplified configuration. In particular, it is possible to easily peel off the electrodeposited zinc powder and to divide it into the required size while it is peeled off and falling. In this manner, zinc can be obtained from zinc-containing material in a manner in which all work processes such as electrolysis, peeling, recovery, transport, and unloading are replaced by mechanized and automated processes that do not rely on human power.

[0030] Furthermore, according to the electrolytic apparatus in the second aspect of the present invention, the plurality of electrode members are a plurality of electrode plates, each being a strip-shaped flat plate member, and the predetermined gap is set in the range of 1 mm to 20 mm. Therefore, with a simplified configuration, the electrodeposited zinc powder can be attached in an appropriately divided state, the electrodeposited zinc powder can be easily peeled off, and it can be divided into the required size while being peeled off and dropped.

[0031] Furthermore, according to the electrolytic apparatus in the third aspect of the present invention, since a resin member is fitted into a predetermined gap, deformation of the electrode plate can be suppressed.

[0032] Furthermore, according to the electrolytic apparatus in the fourth aspect of the present invention, since the multiple electrode plates face each other in directions perpendicular to the vertical and width directions, and the resin member is a single member to which the multiple electrode plates are attached so that the electrode surfaces are exposed, deformation of the electrode plates can be suppressed even when the electrode plates are made thin by so-called double-layering.

[0033] Furthermore, according to the electrolytic apparatus in the fifth aspect of the present invention, the transport mechanism is a chain conveyor, and the chain conveyor has buckets that scoop up the electrodeposited zinc powder in an area corresponding to the entire area where the electrodeposited zinc powder is stripped from the cathode and falls downward to the electrolytic cell, so that the electrodeposited zinc powder can be reliably scooped up and transported.

[0034] Furthermore, according to the electrolytic apparatus in the sixth aspect of the present invention, the chain conveyor exhibits a transport track that extends vertically to transport the electrodeposited zinc powder to a position above the liquid surface of the sodium hydroxide aqueous solution. The bucket is positioned such that when it scoops up the electrodeposited zinc powder, its opening faces parallel to the bottom of the electrolytic cell; when the bucket rises upward, its opening faces upward; and after the bucket has exceeded the liquid surface of the sodium hydroxide aqueous solution, its opening faces diagonally downward. Thus, the electrodeposited zinc powder can be transported with a simplified and compact configuration.

[0035] Furthermore, according to the electrolytic apparatus in the seventh aspect of the present invention, the chain conveyor has a folded portion that folds upward from the bottom of the electrolytic cell in the vertical direction, and the folded portion has a curved shape with a predetermined bending radius, so that the electrodeposited zinc powder that accumulates in the folded portion of the conveying track can be prevented from clogging.

[0036] Furthermore, according to the electrolytic apparatus in the eighth aspect of the present invention, the transport mechanism is a belt conveyor, and the belt conveyor has a receiving section that corresponds to the entire area of ​​the falling area of ​​the electrodeposited zinc powder that is stripped from the cathode and falls downward to the electrolytic cell, so that the electrodeposited zinc powder can be reliably received and transported.

[0037] Furthermore, according to the electrolytic apparatus in the ninth aspect of the present invention, the belt conveyor has a conveying track that extends vertically to transport the electrodeposited zinc powder to a position above the liquid surface of the sodium hydroxide aqueous solution, and also has a bucket that maintains a posture that suppresses the falling of the electrodeposited zinc powder. Therefore, the electrodeposited zinc powder can be transported with a simplified and compact configuration.

[0038] Furthermore, according to the electrolytic apparatus in the tenth aspect of the present invention, the belt conveyor has a folded portion that folds upward from the bottom of the electrolytic cell in the vertical direction, and the folded portion has a curved shape with a predetermined bending radius, so that the electrodeposited zinc powder that accumulates therein can be prevented from clogging the folded portion of the conveying track.

[0039] Furthermore, according to the electrolytic apparatus in the eleventh aspect of the present invention, since the bucket has a perforated or mesh structure that allows the sodium hydroxide aqueous solution to pass through, the electrodeposited zinc powder can be transported while reliably separating it from the sodium hydroxide aqueous solution.

[0040] Furthermore, according to the electrolytic apparatus in the twelfth aspect of the present invention, the transport mechanism transports the electrodeposited zinc powder intermittently in response to the elapsed period during which the electrodeposited zinc powder is peeled off at predetermined intervals, thereby enabling efficient recovery and transport of the electrodeposited zinc powder.

[0041] Furthermore, the electrolytic apparatus in the thirteenth aspect of the present invention is further equipped with a crusher for crushing aggregates contained in the electrodeposited zinc powder. Therefore, even if aggregates of, for example, about 10 mm in size are formed in the electrodeposited zinc powder, which can entrain the electrolyte (a sodium hydroxide aqueous solution) and make subsequent cleaning difficult, such aggregates can be appropriately divided into smaller pieces.

[0042] Further, according to the electrolysis apparatus in the 14th aspect of the present invention, since it further includes a centrifuge for centrifuging the electrodeposited zinc powder that has passed through the crusher, the electrolytic solution, which is an aqueous sodium hydroxide solution, and such electrodeposited zinc powder can be appropriately separated.

[0043] Further, according to the electrolysis apparatus in the 15th aspect of the present invention, the electrodeposited zinc powder from which the aqueous sodium hydroxide solution adhering to the electrodeposited zinc powder has been separated by centrifuging the electrodeposited zinc powder with a centrifuge is repeatedly washed with water 3 to 6 times. Therefore, zinc that has been appropriately purified can be obtained.

[0044] Further, according to the electrolysis apparatus in the 16th aspect of the present invention, since it further includes a press molding machine that uses the electrodeposited zinc powder that has passed through the centrifuge as a molded body, a zinc molded body that has been appropriately molded can be obtained.

[0045] Further, according to the electrolysis apparatus in the 17th aspect of the present invention, the atmosphere when filtering the electrodeposited zinc powder from the aqueous sodium hydroxide solution adhering to the electrodeposited zinc powder carried out of the electrolytic cell, and the atmosphere when washing the electrodeposited zinc powder separated by filtering the electrodeposited zinc powder from the aqueous sodium hydroxide solution adhering to the electrodeposited zinc powder carried out of the electrolytic cell with water are inert gas atmospheres. Therefore, zinc maintained in a clean state can be obtained.

[0046] Further, according to the electrolysis apparatus in the 18th aspect of the present invention, since the electrolytic cell, the applying mechanism, the peeling mechanism, and the conveying mechanism are made of resin or ceramics, the durability of the electrolysis apparatus can be enhanced.

[0047] Further, according to the electrolysis apparatus in the 19th aspect of the present invention, the plurality of electrode members are each rod-shaped members, and a predetermined gap is set in the range of 1 mm or more and 20 mm or less. Therefore, with a simplified configuration, the electrodeposited zinc powder can be adhered in an appropriately divided state, while making it easy to peel off the electrodeposited zinc powder, and it can be divided into a required size while being peeled off and dropped.

[0048] Further, according to the electrolysis device in the 20th aspect of the present invention, since the lower ends of the plurality of electrode members are held by the holding member, deformation of the electrode members can be suppressed.

[0049] FIG. 1 is a side view schematically showing the configuration of an electrolysis device in an embodiment of the present invention. FIG. 2 is a top view of FIG. 1. FIG. 3 is a diagram schematically showing the configuration of a bucket included in the electrolysis device in the present embodiment. FIG. 4 is a front view of an anode of the electrolysis device in the present embodiment. FIG. 5 is a front view of a cathode of the electrolysis device in the present embodiment. FIG. 6 is a cross-sectional view taken along the line A-A of FIG. 5. FIG. 7 is a front view of a cathode of another example of the electrolysis device in the present embodiment. FIG. 8 is a cross-sectional view taken along the line B-B of FIG. 7 and corresponds in position to the cross-sectional view taken along the line A-A of FIG. 5. FIG. 9 is a cross-sectional view of a cathode of yet another example of the electrolysis device in the present embodiment and corresponds in position to the cross-sectional view taken along the line A-A of FIG. 5. FIG. 10 is a front view of a cathode of yet another example of the electrolysis device in the present embodiment. FIG. 11 is a cross-sectional view of a cathode of yet another example of the electrolysis device in the present embodiment and corresponds in position to the cross-sectional view taken along the line A-A of FIG. 5. FIG. 12 is a front view showing a state in which a peeling mechanism is combined with the cathode of the electrolysis device in the present embodiment. FIG. 13 is a top view of FIG. 12. FIG. 14 is a side view schematically showing the configuration of another example of the electrolysis device in the present embodiment. FIG. 15 is a top view of FIG. 14. FIG. 16 is a diagram schematically showing the configuration of a bucket included in another example of the electrolysis device in the present embodiment.

[0050] Hereinafter, the electrolysis device in the embodiment of the present invention will be described in detail with appropriate reference to the drawings.

[0051] Figure 1 is a schematic side view showing the configuration of an electrolytic apparatus in an embodiment of the present invention, and Figure 2 is a top view of Figure 1. Figure 3 is a schematic diagram showing the configuration of the buckets in the electrolytic apparatus in this embodiment. Figure 4 is a front view of the anode of the electrolytic apparatus in this embodiment. Figure 5 is a front view of the cathode of the electrolytic apparatus in this embodiment, and Figure 6 is a cross-sectional view taken along line A-A in Figure 5. Figure 7 is a front view of the cathode of another example of the electrolytic apparatus in this embodiment, and Figure 8 is a cross-sectional view taken along line B-B in Figure 7, which corresponds in position to the cross-sectional view taken along line A-A in Figure 5. Figure 9 is a cross-sectional view of the cathode of yet another example of the electrolytic apparatus in this embodiment, which corresponds in position to the cross-sectional view taken along line A-A in Figure 5. Figure 10 is a front view of the cathode of yet another example of the electrolytic apparatus in this embodiment. Figure 11 is a cross-sectional view of the cathode of yet another example of the electrolytic apparatus in this embodiment, which corresponds in position to the cross-sectional view taken along line A-A in Figure 5. Figure 12 is a front view showing the electrolytic device in this embodiment with the peeling mechanism attached to the cathode, and Figure 13 is a top view of Figure 12. In the figures, the x, y, and z axes form a three-axis orthogonal coordinate system, with the z axis being the vertical direction, the x axis being the width direction, the y axis being the thickness direction, the negative side of the y axis being the front side, the z axis being the up and down direction, and the positive and negative directions of the z axis being referred to as the up and down directions, respectively.

[0052] As shown in Figures 1 to 13, the electrolytic apparatus S1 of this embodiment comprises an anode 10 and a cathode 20 that constitute electrodes E facing each other in the y-axis direction, an electrolytic cell 30 that houses a portion of the anode 10 and cathode 20, a peeling mechanism 40 provided for the cathode 20, an application mechanism 46 that applies at least one of an impact force and vibration to the cathode 20, a power supply 50 that supplies current to the anode 10 and cathode 20, and a chain conveyor 60 which is a transport mechanism that is partially housed in the electrolytic cell 30. Typically, a plurality of anodes 10 and cathodes 20 are arranged side by side in the y-axis direction. The electrolytic apparatus S1 may also be equipped with a crusher 70, a centrifuge 80, and a press molding machine 90 as needed.

[0053] More specifically, the anode 10 has a conductive electrode plate 12 and a transverse member 14. The electrode plate 12 is typically a rectangular flat plate parallel to the x-z plane, connected to the transverse member 14, and supported so as to hang down from the transverse member 14 and be immersed in the electrolytic bath 32 of the electrolytic cell 30. Furthermore, the electrode plate 12 is preferably made of pure nickel or a so-called DSE (Dimensionally Stable Electrode: platinum group coated titanium electrode) from the viewpoint of electrolysis stability, etc. The transverse member 14 is connected to the positive electrode side of the power supply 50 via a busbar (typically made of copper) 52 or the like.

[0054] Each cathode 20 has conductive electrode plates 22 and transverse members 24. The electrode plates 22 are electrode members in the cathode 20, and are typically a plurality of electrode members arranged adjacent to each other in the x-axis direction in one cathode 20. Each electrode plate 22 is a vertically elongated rectangular plate parallel to the x-z plane and elongated in the vertical direction, with the x, y, and z axes corresponding to the width, thickness, and vertical (longitudinal) directions of each electrode plate 22, and is connected to the transverse members 24 and supported so as to hang down from the transverse members 24 and be immersed in the electrolytic bath 32 of the electrolytic cell 30. In each electrode plate 22, adjacent ones in the x-axis direction, which is their width direction, are spaced apart to form a gap with a predetermined distance D. That is, such gaps are arranged parallel to the x-axis direction, and the direction of this arrangement coincides with the direction of the arrangement of the juxtaposed electrode plates 22. Furthermore, each electrode plate 22 has an electrode surface 22a which is a pair of main surfaces that are defined by the x and y axes, are parallel to the x-z plane, and face each other in the direction of the y axis. The electrode plates 22 are typically made of pure magnesium or a magnesium alloy, and the transverse members 24 are connected to the negative electrode side of the power supply 50 via a busbar (typically made of copper) 54 or the like. Here, it is preferable that the distance (gap width) D between adjacent electrode plates 22 in the direction of the x axis is set in the range of 1 mm to 20 mm. This is because, when the distance D becomes shorter than 1 mm, it becomes difficult to say that the electrode surface 22a of the electrode plate 22 is divided by the gaps between adjacent electrode plates 22 in the x-axis direction, so that the electrodeposited zinc powder, which is an electrolytic product, can be easily peeled off and divided and loosely attached. On the other hand, when the distance D exceeds 20 mm, the proportion of the electrode surface 22a to the entire cathode 20 in the x-axis direction decreases, and the proportion of the area of ​​the electrodeposited surface that substantially corresponds to the electrode surface 22a on the anode 10 side decreases too much, which reduces the equipment productivity of the cathode 20 itself. Furthermore, considering that magnesium is a metal material that is difficult to roll, and that it is difficult to obtain relatively wide magnesium flat sheets on the market in practice, applying magnesium flat sheets to the cathode 20 in a strip shape is significant in this respect.

[0055] Here, as shown in Figures 5 and 6, the simplest configuration of the cathode 20 is that the gap between adjacent electrode plates 22 in the x-axis direction is a space that maintains a distance D without the interposition of another member. In the case of such a cathode 20, the deposited electrodeposited zinc powder adheres to the electrode plates 22 by slightly wrapping around into the gap between adjacent electrode plates 22 in the x-axis direction and straddling that gap. Therefore, from the viewpoint of separating the electrodeposited zinc powder so that it can be easily peeled off and dropped, it is preferable that the gap between adjacent electrode plates 22 in the x-axis direction extends vertically while maintaining a constant distance D.

[0056] Furthermore, various other examples of cathodes 20 can be considered, but for example, as shown in Figures 7 and 8, an electrically insulating resin member 28, which is a separate component, is attached by adhesive or the like to the gap between adjacent electrode plates 22 at a distance D in the x-axis direction, and the electrode plates 22 are bonded to each other by the resin member 28, thereby suppressing deformation of the electrode plates 22. In the case of such a cathode 120, the deposited electrodeposited zinc powder adheres to the electrode plates 22 so as to straddle the resin member 28. Also, in the figures, the resin member 28 has a configuration that protrudes from the electrode surface 22a in the y-axis direction, but if necessary, it may have a configuration that is recessed from the electrode surface 22a in the y-axis direction, or that is flush with the electrode surface 22a. In addition, in the case of such a cathode 120, as shown in the figure, the resin member 28 may also be attached to the outer edge of the electrode plate 22 located on the most positive or negative side in the x-axis direction, that is, the outermost side in the width direction, to suppress deformation of the outer edge. Furthermore, the electrodeposited zinc powder deposited on the electrode surface 22a may extend beyond the electrode surface 22a and adhere more loosely to the resin member 28 than to the electrode surface 22a.

[0057] Furthermore, as shown in Figure 9, the cathode 220 has electrode plates 22 facing each other in the y-axis direction, and a single, separate, electrically insulating insulating member 28' is attached between these opposing electrode plates 22 by adhesive or the like. In other words, the electrode plates 22 are attached to the insulating member 28' by adhesive or the like, and this configuration suppresses deformation of the electrode plates 22 while using electrode plates 22 with a thin thickness in the y-axis direction. In the case of such a cathode 220, from the viewpoint of reducing the overall thickness of the cathode 220 in the y-axis direction, it is preferable that the insulating member 28' in the gap between adjacent electrode plates 22 in the x-axis direction be set so as to be recessed below the electrode surface 22a in the y-axis direction, or so as to be flush with the electrode surface 22a.

[0058] Furthermore, as shown in Figure 10, a holding member M is provided to the cathode 320 shown in Figures 5 and 6, which holds the lower end of the electrode plate 22 and is electrically insulating, thereby suppressing deformation of the electrode plate 22. Also, as shown in Figure 11, a rod-shaped electrode member 420 made of magnesium wire may be used instead of the strip-shaped electrode plate 22 shown in Figures 5 to 10, in which case the electrode surface 422a becomes the outer circumferential surface of a circle rather than a flat surface.

[0059] As described above, various other examples of the cathode 20 are conceivable, but in the following explanation, for convenience, we will mainly describe the one having a strip-shaped electrode plate 22.

[0060] The electrolytic cell 30 is a container that houses an electrolytic bath 32 in which an aqueous solution of zinc-containing sodium hydroxide containing zinc components is used as the electrolyte. It is electrically insulating and is typically made of resin or ceramic. As the electrolyte, it is possible to use zinc-containing sodium hydroxide obtained by reducing zinc-containing dust as a raw material and further concentrating the zinc-containing material, and then leaching it with an aqueous solution of sodium hydroxide. Here, using the power supply 50 as a power source, an electric current is passed between the electrode plate 12 of the anode 10 and the electrode plate 22 of the cathode 20 to electrolyze the aqueous solution of zinc-containing sodium hydroxide as the electrolyte, and electrodeposited zinc powder, which is the electrolytic product, is deposited on the electrode surface 22a of the electrode plate 22 of the cathode 20. In this process, the electrodeposited zinc powder deposited on the electrode surface 22a adheres to the electrode surface 22a while crossing the gaps adjacent to the electrode plate 22 (or the resin members 28, 28' if resin members 28, 28' are provided). As a result, changes occur in the adhesion shape and adhesion density of the electrodeposited zinc powder in these gaps (or resin members 28, 28'), and the electrodeposited zinc powder separated by these gaps (or resin members 28, 28') adheres loosely to the electrode surface 22a. The zinc-containing dust used as raw material contains at least a zinc compound such as zinc oxide, and may be primary or secondary dust such as electric furnace dust, blast furnace dust, blast furnace / converter dust, or RHF (Rotary Heat Furnace) dust, or calcined ore from zinc concentrate. The electrolytic tail liquid of the electrolytic device S1 may be used as the sodium hydroxide aqueous solution. Furthermore, if necessary, a purification treatment may be performed to remove impurities contained in the raw materials before leaching the zinc-containing material with an aqueous sodium hydroxide solution.

[0061] The peeling mechanism 40 is provided in the electrolytic cell 30 so as to face the cathode 20 and has a support member 42 fixed to the electrolytic cell 30 and a contact member (scraper) 44 rotatably supported by the support member 42. The support member 42 and the contact member 44 are electrically insulating and are typically made of resin or ceramic. The upper end of the contact member 44 is connected to a rotating shaft of the support member 42 (not shown). When the rotating shaft of the support member 42 rotates, the contact member 44 rotates around that point to sweep the electrode surface 22a of the electrode plate 22 in a fan shape, contacting and peeling off the electrodeposited zinc powder deposited and adhering to the electrode surface 22a, thereby obtaining the electrodeposited zinc powder 5 peeled off from the electrode surface 22a. Here, from the viewpoint of ensuring that the contact member 44 contacts and more reliably removes the electrodeposited zinc powder deposited and adhering to the electrode surface 22a, it is preferable that when the contact member 44 sweeps the electrode surface 22a of the electrode plate 22 in a fan shape, the contact member 44 rotates from its initial hanging position (shown by a solid line in Figure 12), sweeps the electrode surface 22a from bottom to top in a fan shape, and then sweeps the electrode surface 22a from top to bottom in a fan shape to return to the initial state. The electrodeposited zinc powder 5 thus peeled off will descend vertically downward in the direction of gravity within the electrolytic bath 32, and the electrodeposited zinc powder 5 will be divided as it is peeled off and descends. From the viewpoint of ensuring that the contact member 44 reliably contacts the electrodeposited zinc powder adhering to the electrode surface 22a of the electrode plate 22, it is preferable to provide the contact member 44 at both ends of the cathode 20 in the x-axis direction on each side of the electrode surfaces 22a that are opposite to each other in the y-axis direction. Here, the peeling mechanism 40 brings the contact member 44 into contact with the electrode surface 22a at a predetermined rotation angle and angular velocity at each timing when it can be evaluated that a predetermined amount of electrodeposited zinc powder has adhered to the electrode surface 22a, that is, at predetermined intervals, to peel it off. At this time, when the contact member 44 comes into contact with the electrode surface 22a, it is possible that the entire electrodeposited zinc powder may be peeled off substantially at once, so it is preferable to cut off the supply of current to the anode 10 and cathode 20 before the contact member 44 rotates. If necessary, the rotation angle of the contact member 44 may be limited or the timing of its rotation may be adjusted so that the entire electrodeposited zinc powder attached to the electrode surface 22a is not peeled off substantially at once.

[0062] The application mechanism 46 typically has an application member, such as a hammer or vibrator (not shown), which is attached to the transverse member 24 of the cathode 20 and applies at least one of intermittent impact force or continuous vibration to the electrode plate 22 via the transverse member 24. In other words, the application mechanism 46 has the function of vibrating the electrode plate 22 in the y-axis direction by operating the application member. The application member is electrically insulating and is typically made of resin or ceramic. Regarding the timing of the application mechanism 46 applying at least one of the impact force and vibration to the electrode plate 22, from the viewpoint of reinforcing the peeling function of the peeling mechanism 40 and increasing the amount of peeling of the electrodeposited zinc powder, it is preferable that the application of at least one of the impact force and vibration starts before the rotation of the contact member 44 starts, and that the application of at least one of the impact force and vibration has finished by the time the rotation of the contact member 44 starts. The application mechanism 46 may be provided on one side of the cathode 20, or on both sides of the cathode 20, as needed.

[0063] The chain conveyor 60 includes a bucket 62 for receiving the peeled electrodeposited zinc powder 5 as electrodeposited zinc powder 6 being conveyed, a chain 64 that moves the bucket 62 and forms a conveying track T, and a sprocket 66 that drives the chain 64. The bucket 62, chain 64, and sprocket 66 are electrically insulating and are typically made of resin or ceramics. Here, the transport trajectory T of the chain 64 extends from above the electrolytic cell 30 in the negative z-axis direction, passes through the liquid surface 32a of the electrolytic bath 32, continues to extend further in the negative z-axis direction within the electrolytic bath 32, then as the bottom wall 30a of the electrolytic cell 30 approaches, it curves in the negative x-axis direction and extends in that direction, then as the side wall 30b on the negative x-axis side of the electrolytic cell 30 approaches, it curves in the negative z-axis direction, then curves in the positive x-axis direction and turns to extend in that direction, then as the side wall 30b on the positive x-axis side of the electrolytic cell 30 approaches, it curves in the positive z-axis direction and extends in that direction, passing through the liquid surface 32a of the electrolytic bath 32 and reaching above the electrolytic cell 30. In other words, in the chain conveyor 60, the detached electrodeposited zinc powder 5 that descends within the electrolytic cell 30 and accumulates on the bottom wall 30a of the electrolytic cell 30 is scooped up from the bottom wall 30a of the electrolytic cell 30 by the buckets 62 over a wide area equal to or greater than the falling area 34 and collected in the buckets 62. The electrodeposited zinc powder 6 collected in the buckets 62 is then transported along the transport track T of the chain 64 to a position above the liquid level 32a of the electrolytic bath 32. Typically, the falling area 34 is located below the electrode E and, in a top view, has an area greater than or equal to the area of ​​the electrode E, and has an outer contour line that is similar in shape to the outer contour line of the electrode E and surrounds the outer contour line of the electrode E. Furthermore, the length in the y-axis direction of each of the multiple buckets 62 is set to be longer than the length in the y-axis direction of the falling area 34. Here, from the viewpoint of improving the efficiency of transporting the peeled-off electrodeposited zinc powder 5, it is preferable that the chain conveyor 60 starts transporting the peeled-off electrodeposited zinc powder 5 after a peeling period has elapsed in which the peeling mechanism 40 rotates the contact member 44 to peel off the electrodeposited zinc powder adhering to the electrode surface 22a of the electrode plate 22 of the cathode 20 at predetermined intervals.Furthermore, the portion of the chain 64 extending in the positive x-axis direction in the transport track T extends in the x-axis direction, which is both the width direction of the adjacent electrode plates 22 and the direction of the arrangement of gaps where a predetermined distance D is defined between adjacent electrode plates 22, with a length longer than the x-axis length of the cathode 20, so as to properly scoop up the electrodeposited zinc powder 5 detached from the electrode surface 22a with the bucket 62 and securely contain it there. Furthermore, the portion of the chain 64 extending in the positive z-axis direction in the transport track T extends in the positive z-axis direction, which is the vertical direction (longitudinal direction) of the cathode 20, on the x-axis side of the electrode plate 22 located furthest towards the positive x-axis within the cathode 20, so as to reliably scoop up the electrodeposited zinc powder 5 detached from the electrode surface 22a with the bucket 62 and securely contain it there, before changing its direction of extension to the positive z-axis direction. Furthermore, from the viewpoint of suppressing the unnecessary expansion of the chain conveyor 60 in the x-axis and y-axis directions, it is preferable that the transport track T extending in the z-axis direction be parallel to the z-axis, however, in practical terms, an inclination of a few degrees, indicated by an angle θ with respect to the z-axis, is permissible. In addition, from the viewpoint of suppressing the accumulation of the detached electrodeposited zinc powder 5, which descends inside the electrolytic cell 30 and accumulates on the bottom wall 30a of the electrolytic cell 30, in the corners between the bottom wall 30a and the side walls 30b of the electrolytic cell 30, it is preferable to round off the corners between the bottom wall 30a and the side walls 30b in the region where the bucket 62 changes direction from the positive x-axis to the positive z-axis direction according to the transport track T, thereby giving it an R-shape. Furthermore, the bucket 62 has an opening 62a at one end, and its shovel-shaped end can scoop up the electrodeposited zinc powder 5, allowing the electrodeposited zinc powder 6 to be contained inside through the opening 62a and transported. The wall of the bucket 62 has a hole structure with multiple holes 62b, which are through holes of a size that allows the zinc-containing sodium hydroxide aqueous solution of the electrolytic bath 32 to be discharged while not discharging the electrodeposited zinc powder 6. When scooping up the electrodeposited zinc powder 5, the bucket 62 takes an orientation with the opening 62a facing the positive x-axis, when rising upwards, the opening 62a takes an orientation with the opening 62a facing the positive z-axis, and after exceeding the liquid level 32a of the electrolytic bath 32, the opening 62a takes an orientation with the opening 62a facing diagonally in the negative z-axis direction. The multiple holes 62b may be realized by a mesh structure.Furthermore, from the viewpoint of holding and transporting the electrodeposited zinc powder 6 without scooping it up and dropping it downwards, it is also possible to simplify the bucket 62 and replace it with a plate-shaped member.

[0064] The crusher 70 is positioned after the bucket 62 when the electrodeposited zinc powder 6 contained in the bucket 62 has reached a position above the liquid level 32a of the electrolytic bath 32, and the bucket 62 approaches the end on the positive x-axis side, following the transport track T of the chain 64 which extends in the positive x-axis direction and the negative z-axis direction. The crusher 70 has an agitator 72. When the bucket 62 approaches the end on the positive x-axis side, the electrodeposited zinc powder 6 contained inside it is removed from the bucket 62 by falling or the like, and is placed inside the crusher 70 where it is later finely crushed. This is because the electrodeposited zinc powder deposited on the electrode surface 22a of the electrode plate 22 of the cathode 20 in the electrolytic bath 32 has a strong tendency to form aggregates, and when the electrodeposited zinc powder is deposited on the electrode surface 22a, adjacent powder particles exhibit weak bonds. Therefore, this also takes into consideration that such electrodeposited zinc powder tends to form aggregates. Such aggregates can grow to a size of about 10 mm, and aggregates of this size tend to entrain the electrolyte, which is an aqueous sodium hydroxide solution, making it difficult to wash the electrodeposited powder in subsequent processes. Furthermore, from the viewpoint of suppressing the unwanted influence of the atmospheric gas on the electrodeposited zinc powder 6 discharged from the electrolytic cell 30, it is preferable to maintain an inert gas atmosphere before, during, after, and in each subsequent process of placing the electrodeposited zinc powder 6 inside the crusher 70.

[0065] The centrifugal separator 80 is positioned next to the crusher 70. The electrodeposited zinc powder 7, which has been crushed by the crusher 70 and is accompanied by an aqueous sodium hydroxide solution (an electrolyte), is centrifuged to separate the aqueous sodium hydroxide solution from the electrodeposited zinc powder 7. After this separation, the electrodeposited zinc powder 7 is rotated in the centrifugal separator 80 while water is sprayed on it to wash it. From the viewpoint of properly performing this washing, it is preferable to change the water supplied to the centrifugal separator 80 after each wash and repeat the washing process three to six times for a predetermined time. Next, while the electrodeposited zinc powder 7 is rotating, a rust inhibitor is sprayed onto the electrodeposited zinc powder 7 in the centrifugal separator 80 instead of water to perform rust prevention treatment. In this way, by applying a rust inhibitor to the washed electrodeposited zinc powder 7 in the centrifugal separator 80, an electrodeposited zinc powder 8 coated with a rust inhibitor is obtained. Examples of such rust inhibitors include BTA (benzotriazole). In addition to performing such washing and rust prevention treatments collectively using the centrifugal separator 80, separate washing machines and rust prevention machines may be provided to perform each treatment individually.

[0066] The press molding machine 90 is positioned next to the centrifugal separator 80 and compresses the electrodeposited zinc powder 8, which has been treated with a rust inhibitor by the centrifugal separator 80, to obtain molded electrodeposited zinc powder 9 as the final product. The press molding machine 90 has a receiving mold 92 for receiving the electrodeposited zinc powder 8 and applies a pressing force F with a pressing mold (not shown) to pressurize and compress the electrodeposited zinc powder 8, thereby obtaining electrodeposited zinc powder (metallic zinc: zinc molded body) 9, which is a press molded product conforming to the shape of the mold. If necessary, the press molding machine 90 may also compress electrodeposited zinc powder 8 that has not been treated with a rust inhibitor.

[0067] In the electrolytic apparatus S1 of this embodiment, cathodes 20, 120, 220, 320, and 420 are connected to the same potential and each has a plurality of electrode members 22, 422 that define electrode surfaces 22a, 422a to which electrodeposited zinc powder adheres. The plurality of electrode members 22, 422 are arranged with a predetermined gap between them in the width direction such that the electrode surface 22a is aligned in the width direction perpendicular to the vertical direction. This allows the electrodeposited zinc powder to adhere to the cathode 20 in a divided manner, making it easier to peel it off. Furthermore, the electrodeposited zinc powder 5 after being stripped off is made into powder of an appropriate size, and the stripped electrodeposited zinc powder 5 can be received and transported with a simplified configuration. In particular, the electrodeposited zinc powder 5 can be easily stripped off, and while it is being stripped off and dropped, it can be divided into the required size, and all work processes such as electrolysis, stripping, recovery, transport, and unloading can be replaced with mechanized and automated processes that do not rely on human labor, thereby enabling the acquisition of zinc from zinc-containing material.

[0068] Furthermore, in the electrolytic apparatus S1 of this embodiment, the multiple electrode members 22 are multiple electrode plates, each being a strip-shaped flat plate, and the predetermined gap is set in the range of 1 mm to 20 mm. Therefore, with a simplified configuration, the electrodeposited zinc powder can be attached in an appropriately divided state, the electrodeposited zinc powder can be easily peeled off, and it can be divided into the required size while being peeled off and falling.

[0069] Furthermore, in the electrolytic device S1 of this embodiment, since the resin members 28 and 28' are fitted into predetermined gaps, deformation of the electrode plate 22 can be suppressed.

[0070] Furthermore, in the electrolytic device S1 of this embodiment, the multiple electrode plates 22 face each other in directions perpendicular to the vertical and width directions, and the resin member 28' is a single member attached to the multiple electrode plates 22 so as to expose the electrode surface 22a. Therefore, even when the electrode plates 22 are made thin by so-called double-layering, deformation of the electrode plates 22 can be suppressed.

[0071] Furthermore, in the electrolytic apparatus S1 of this embodiment, the transport mechanism is a chain conveyor 60, and the chain conveyor 60 has buckets 62 that scoop up the electrodeposited zinc powder 5 in an area corresponding to the entire area 34 where the electrodeposited zinc powder 5 is stripped off from the cathode 20 and falls downward to the electrolytic cell 30. Therefore, the electrodeposited zinc powder 5 can be reliably scooped up and transported.

[0072] Furthermore, in the electrolytic apparatus S1 of this embodiment, the chain conveyor 60 exhibits a transport track T that extends in the vertical direction to transport the electrodeposited zinc powder 5 to a position above the liquid surface of the sodium hydroxide aqueous solution. When the bucket 62 scoops up the electrodeposited zinc powder 5, the opening 62a of the bucket 62 is positioned parallel to the bottom of the electrolytic cell 30. When the bucket 62 rises upward, the opening 62a is positioned upward. After the bucket 62 has exceeded the liquid surface 32a of the sodium hydroxide aqueous solution, the opening 62a is positioned diagonally downward. Thus, the electrodeposited zinc powder 6 can be transported with a simplified and compact configuration.

[0073] Furthermore, in the electrolytic apparatus S1 of this embodiment, the chain conveyor 60 has a folded portion that folds upward from the bottom of the electrolytic cell 30 in the vertical direction, and the folded portion has a curved shape with a predetermined bending radius R, so that the electrodeposited zinc powder 5 that accumulates in the folded portion of the transport track T does not get stuck.

[0074] Furthermore, in the electrolytic apparatus S1 of this embodiment, since the bucket 62 has a perforated or mesh structure that allows the sodium hydroxide aqueous solution to pass through, the electrodeposited zinc powder 6 can be transported while reliably separating it from the sodium hydroxide aqueous solution.

[0075] Furthermore, in the electrolytic apparatus S1 of this embodiment, the chain conveyor 60 transports the electrodeposited zinc powder 6 after a peeling period in which the electrodeposited zinc powder is peeled off at predetermined intervals has elapsed, so the electrodeposited zinc powder 5 can be efficiently recovered and transported.

[0076] Furthermore, the electrolytic apparatus S1 of this embodiment is further equipped with a crusher 0 for crushing aggregates contained in the electrodeposited zinc powder 6. Therefore, even if aggregates of, for example, about 10 mm in size are formed in the electrodeposited zinc powder 6, which can entrain the electrolyte (a sodium hydroxide aqueous solution) and make subsequent cleaning difficult, these aggregates can be appropriately divided into smaller pieces.

[0077] Furthermore, the electrolytic apparatus S1 of this embodiment is further equipped with a centrifuge 80 for centrifuging the crushed electrodeposited zinc powder 7 that has passed through the crusher 70, so that the electrolyte, which is an aqueous sodium hydroxide solution, and the electrodeposited zinc powder 7 can be appropriately separated.

[0078] Furthermore, in the electrolytic apparatus S1 of this embodiment, the electrodeposited zinc powder 7, from which the aqueous sodium hydroxide solution attached to the electrodeposited zinc powder 7 has been separated by centrifugal separation in the centrifugal separator 80, is washed with water three to six times. This contributes to obtaining water-washed electrodeposited zinc powder 8 and appropriately cleaned zinc.

[0079] Furthermore, the electrolytic apparatus S1 of this embodiment is further equipped with a press molding machine 90 that molds the electrodeposited zinc powder 8, which has passed through the centrifugal separator 80, into a molded body, thereby enabling the production of a properly molded zinc molded body 9.

[0080] Furthermore, in the electrolytic apparatus S1 of this embodiment, the atmosphere when filtering the electrodeposited zinc powder 6 from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder 6 that has been transported outside the electrolytic cell 30, and the atmosphere when washing the electrodeposited zinc powder 6 separated by filtering from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder 6 that has been transported outside the electrolytic cell 30, are both inert gas atmospheres. Therefore, zinc can be obtained while maintaining a clean state.

[0081] Furthermore, in the electrolytic device S1 of this embodiment, since the electrolytic cell 30, the application mechanism 46, the peeling mechanism 40, and the chain conveyor 60 are made of resin or ceramic, the durability of the electrolytic device S1 can be increased.

[0082] Furthermore, in the electrolytic device S1 of this embodiment, each of the multiple electrode members 422 is a rod-shaped member, and the predetermined gap is set in the range of 1 mm to 20 mm. Therefore, with a simplified configuration, the electrodeposited zinc powder can be attached in an appropriately divided state, the electrodeposited zinc powder can be easily peeled off, and it can be divided into the required size while being peeled off and falling.

[0083] Furthermore, in the electrolytic device S1 of this embodiment, the lower ends of the multiple electrode members 22 and 422 are held by the holding member M, so that deformation of the electrode members 22 and 422 can be suppressed.

[0084] Now, since various alternative examples of the electrolytic apparatus S1 of this embodiment are conceivable, they will be described in more detail below with reference to Figures 14 to 16.

[0085] Figure 14 is a schematic side view showing the configuration of an alternative electrolytic apparatus in this embodiment, and Figure 15 is a top view of Figure 14. Figure 16 is a schematic diagram showing the configuration of the buckets in the alternative electrolytic apparatus in this embodiment.

[0086] As shown in Figures 14 to 16, the main difference between the electrolytic apparatus S2 in this alternative example and the electrolytic apparatus S1 described above is that the chain conveyor 60 has been replaced with a belt conveyor 110, and the configurations that are not specifically noted are the same as those of electrolytic apparatus S1. The belt conveyor 110 has a bucket 112 for receiving the peeled electrodeposited zinc powder 5 as electrodeposited zinc powder 6 being conveyed, a belt 114 on which the bucket 112 is attached and moved, and rollers 116 for driving the belt 114. Specifically, the bucket 112, belt 114, and rollers 116 are electrically insulating and are typically made of resin or ceramics. Furthermore, since the belt 114 has a receiving portion 114a that receives the detached electrodeposited zinc powder 5 descending within the electrolytic bath 32 toward the bottom wall 30a' of the electrolytic cell 30' over a wide area equal to or greater than the falling area 34, the conveying trajectory T' of the belt 114 differs in part from the conveying trajectory T of the chain conveyor 60 of the electrolytic device S1. It extends from above the electrolytic cell 30' in the negative z-axis direction, passes through the liquid surface 32a of the electrolytic bath 32, continues further in the negative z-axis direction within the electrolytic bath 32, and then, just before and above the bottom wall 30a' of the electrolytic cell 30', moves toward the negative x-axis direction. The bucket bends and extends in that direction, and then, as the side wall 30b' on the negative x-axis side of the electrolytic cell 30' approaches, it bends towards the positive z-axis side, then bends towards the positive x-axis, turns around and extends in that direction, and then, as the side wall 30b' on the positive x-axis side of the electrolytic cell 30' approaches, it bends towards the positive z-axis and extends in that direction, thus exhibiting a trajectory that passes through the liquid surface 32a of the electrolytic bath 32 and reaches above the electrolytic cell 30'. Furthermore, the bucket 112 only needs to collect the electrodeposited zinc powder 5 that accumulates on the receiving portion 114a of the belt 114 without scooping it up. The lengths of the receiving portion 114a in the x-axis and y-axis directions are set to be correspondingly longer than the lengths of the falling area 34 in the x-axis and y-axis directions, respectively. Furthermore, the portion of the belt 114 that extends in the positive z-axis direction in the transport trajectory T' reliably maintains the receiving portion 114a, and extends in the positive z-axis direction, which is the vertical direction (longitudinal direction) of the cathode 20, on the positive x-axis side of the electrode plate 22 that is located furthest towards the positive x-axis side of the cathode 20.Here, the region in the electrolytic cell 30' where the corners between the bottom wall 30a' and the side wall 30b' are rounded to give an R shape should be set in the region where the bucket 112 changes direction from the negative x-axis to the positive z-axis according to the transport trajectory T'. Also, since the bucket 112 does not need to scoop up the electrodeposited zinc powder 5, the end of its opening 112a does not need to be shovel-shaped; it is sufficient to hold the electrodeposited zinc powder 6 inside the opening 112a and transport it without letting it fall downwards. Furthermore, the bucket 112 wall is provided with multiple holes 112b, which are through holes of a size that allows the zinc-containing sodium hydroxide aqueous solution of the electrolytic bath 32 to be discharged while not discharging the electrodeposited zinc powder 6, similar to the configuration of the bucket 112 described above. Note that the multiple holes 112b may be realized by a mesh structure. Also, from the viewpoint of holding and transporting the electrodeposited zinc powder 6 without letting it fall downwards, it is possible to simplify the bucket 112 and replace it with a plate-shaped member.

[0087] In the above-described electrolytic apparatus S2, the transport mechanism is a belt conveyor 110, and the belt conveyor 110 has a receiving section 114a that corresponds to the entire area 34 where the electrodeposited zinc powder 5 is peeled off from the cathode 20 and falls downward to the electrolytic cell 30, so that the electrodeposited zinc powder 5 can be reliably received and transported.

[0088] Furthermore, in this separate electrolytic apparatus S2, the belt conveyor 110 has a folded portion that folds upward from the bottom of the electrolytic cell 30 in the vertical direction, and the folded portion has a curved shape with a predetermined bending radius R, so that the electrodeposited zinc powder 5 that accumulates in the folded portion of the transport track T' can be prevented from clogging.

[0089] Furthermore, in this electrolytic apparatus S2, since the bucket 112 has a perforated structure that allows the sodium hydroxide aqueous solution to pass through, the electrodeposited zinc powder 6 can be transported while reliably separating it from the sodium hydroxide aqueous solution.

[0090] Furthermore, in this electrolytic apparatus S2, since the bucket 112 has a perforated structure that allows the sodium hydroxide aqueous solution to pass through, the electrodeposited zinc powder 6 can be transported while reliably separating it from the sodium hydroxide aqueous solution.

[0091] It should be noted that the shape, arrangement, number, etc., of the components of the present invention are not limited to the embodiments described above, and such components can be appropriately modified without departing from the spirit of the invention, such as by appropriately substituting them with those that produce equivalent effects.

[0092] As described above, the present invention provides an electrolytic apparatus that can separate and adhere electrodeposited zinc powder to the cathode to make it easier to peel off, and that can receive and transport the peeled electrodeposited zinc powder in a simplified configuration, and is therefore expected to be widely applicable in the electric arc furnace method, one of the steelmaking processes, when extracting zinc from primary or secondary dust such as blast furnace dust or blast furnace / converter dust, as well as zinc-containing dust such as calcined ore for zinc concentrate, in addition to electric arc furnace dust generated during the melting and smelting of scrap.

[0093] S1, S2... Electrolytic device E... Electrode 5... Electrodeposited zinc powder (exfoliated electrodeposited zinc powder) 6... Electrodeposited zinc powder (electrodeposited zinc powder being transported) 7... Electrodeposited zinc powder (crushed electrodeposited zinc powder) 8... Electrodeposited zinc powder (washed or rust-prevented electrodeposited zinc powder) 9... Electrodeposited zinc powder (molded electrodeposited zinc powder) 10... Anode 12... Electrode plate 14... Horizontal member 20, 120, 220, 320, 420... Cathode 22, 422... Electrode plate 22a, 422a... Electrode surface 24... Horizontal member 28, 28'... Resin member 30, 30'... Electrolytic cell 30a, 30a'... Bottom wall 30b, 30b'... Side wall 32... Electrolytic bath (electrolyte) 32a... Liquid level 34... Dropping area 40... Peeling mechanism 42... Support member 44... Contact member (scraper) 46... Application mechanism 50... Power supply 52, 54... Busbar 60... Chain conveyor 62... Bucket 62a... Opening 62b... Hole 64... Chain 66... ​​Sprocket 70... Crusher 72... Agitator 80... Centrifugal separator 90... Press molding machine 92... Mold 110... Belt conveyor 112... Bucket 112a... Opening 112b... Hole 114... Belt 114a... Receiving part 116... Roller

Claims

1. An electrolytic apparatus for recovering electrolytically produced zinc using a sodium hydroxide aqueous solution containing zinc as an electrolytic bath, comprising: an electrolytic cell containing the sodium hydroxide aqueous solution; an electrode positioned relative to the electrolytic cell so as to be located within the sodium hydroxide aqueous solution and having an anode and a magnesium cathode; an application mechanism for applying at least one of an impact force and vibration to the cathode; a peeling mechanism having a scraper for peeling off electrodeposited zinc powder adhering to the cathode at predetermined intervals inside the electrolytic cell after or while the impact force and vibration have been applied to the cathode; and a transport mechanism for recovering the electrodeposited zinc powder in the sodium hydroxide aqueous solution and transporting it to a position above the liquid level of the sodium hydroxide aqueous solution so that the electrodeposited zinc powder that has been peeled off from the cathode and fallen downward in the vertical direction of the electrolytic cell is transported to the outside of the electrolytic cell. The cathode has a plurality of electrode members, each defined by an electrode surface to which the electrodeposited zinc powder is attached, and the plurality of electrode members are arranged with a predetermined gap between them in the width direction such that the electrode surfaces are arranged side by side in the width direction perpendicular to the vertical direction.

2. The electrolytic apparatus according to claim 1, wherein the plurality of electrode members are a plurality of electrode plates, each being a strip-shaped flat plate member, and the predetermined gap is set to a range of 1 mm or more and 20 mm or less.

3. The electrolytic apparatus according to claim 2, wherein a resin member is fitted into the predetermined gap.

4. The electrolytic apparatus according to claim 3, wherein the plurality of electrode plates face each other in directions perpendicular to the vertical direction and the width direction, and the resin member is a single member to which the plurality of electrode plates are attached so as to expose the electrode surface.

5. The electrolytic apparatus according to claim 1, wherein the conveying mechanism is a chain conveyor, and the chain conveyor has a bucket for scooping up the electrodeposited zinc powder in an area corresponding to the entire area of ​​the falling region of the electrodeposited zinc powder that is stripped from the cathode and falls downward into the electrolytic cell.

6. The electrolytic apparatus according to claim 5, wherein the chain conveyor transports the electrodeposited zinc powder to a position above the liquid level of the sodium hydroxide aqueous solution by exhibiting a transport track that extends in the vertical direction, and the bucket is positioned such that when the bucket scoops up the electrodeposited zinc powder, the opening of the bucket faces in a direction parallel to the bottom of the electrolytic cell, when the bucket rises in the upward direction, the opening of the bucket faces upward, and after the bucket has exceeded the liquid level of the sodium hydroxide aqueous solution, the opening of the bucket faces diagonally downward.

7. The electrolytic apparatus according to claim 5, wherein the chain conveyor has a folded portion that folds back upward from the bottom of the electrolytic cell in the vertical direction, and the folded portion has a bent R shape with a predetermined bending radius.

8. The electrolytic apparatus according to claim 1, wherein the conveying mechanism is a belt conveyor, and the belt conveyor has a receiving portion corresponding to the entire area of ​​the falling region of the electrodeposited zinc powder that is stripped from the cathode and falls downward into the electrolytic cell.

9. The electrolytic apparatus according to claim 8, wherein the belt conveyor exhibits a transport track extending in the vertical direction and transports the electrodeposited zinc powder to a position above the liquid surface of the sodium hydroxide aqueous solution, and has a bucket to suppress the falling of the electrodeposited zinc powder.

10. The electrolytic apparatus according to claim 8, wherein the belt conveyor has a folded portion that folds back upward in the vertical direction from the bottom of the electrolytic cell, and the folded portion has a curved R shape with a predetermined bending radius.

11. The electrolytic apparatus according to claim 5 or 9, wherein the bucket has a perforated structure or a mesh structure that allows the sodium hydroxide aqueous solution to pass through.

12. The electrolytic apparatus according to claim 1, wherein the transport mechanism transports the electrodeposited zinc powder intermittently in response to the elapsed period during which the electrodeposited zinc powder is peeled off at predetermined intervals.

13. The electrolytic apparatus according to claim 1, further comprising a crusher for crushing aggregates contained in the electrodeposited zinc powder.

14. The electrolytic apparatus according to claim 13, further comprising a centrifuge for centrifuging the electrodeposited zinc powder that has passed through the crusher.

15. The electrolytic apparatus according to claim 14, wherein the electrodeposited zinc powder is separated from the aqueous sodium hydroxide solution attached to the electrodeposited zinc powder by centrifugation of the electrodeposited zinc powder in the centrifugal separator, and the electrodeposited zinc powder is washed with water three to six times.

16. The electrolytic apparatus according to claim 15, further comprising a press molding machine for forming a molded body from the electrodeposited zinc powder that has passed through the centrifuge.

17. The electrolytic apparatus according to claim 13, wherein the atmosphere when filtering the electrodeposited zinc powder from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder that has been transported outside the electrolytic cell, and the atmosphere when washing the electrodeposited zinc powder separated by filtering from the sodium hydroxide aqueous solution accompanying the electrodeposited zinc powder that has been transported outside the electrolytic cell, is an inert gas atmosphere.

18. The electrolytic apparatus according to claim 1, wherein the electrolytic cell, the application mechanism, the peeling mechanism, and the transport mechanism are made of resin or ceramics.

19. The electrolytic apparatus according to claim 1, wherein each of the plurality of electrode members is a rod-shaped member, and the predetermined gap is set in the range of 1 mm to 20 mm.

20. The electrolytic apparatus according to claim 1, wherein the downward ends of the plurality of electrode members are held by a holding member.

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