JP6464701B2 - Permanent cathode strain correction device - Google Patents

Description

  The present invention relates to a distortion correction device for a permanent cathode used when electrolytically refining or electrolytically collecting a nonferrous metal.

  In electrolytic smelting of non-ferrous metals such as copper, electrolytic refining and electrowinning are performed. For example, in electrolytic refining, it consists of a crude metal anode manufactured by dry smelting and stainless steel or titanium insoluble in electrolyte After passing an electric current through the electrolyte between the cathode and electrodepositing the target metal on the cathode side, when the target metal is electrodeposited to a predetermined thickness, the target metal is peeled off from the cathode and collected, and then removed. A method of reusing the cathode is generally adopted.

  On the other hand, in electrowinning, a crude metal anode is not used but an insoluble anode is used. The target metal to be deposited is dissolved in an electrolytic bath as a metal salt, and the target metal is electrodeposited on the cathode side by reductive decomposition. A method is generally employed in which when the target metal is electrodeposited to a predetermined thickness, the target metal is peeled off from the cathode and recovered, and the cathode after peeling off is reused.

  The method of reusing the cathode after stripping the electrodeposited target metal as described above is called the permanent cathode method, and the cathode used in this method is called the permanent cathode. In the permanent cathode system, as described above, the electrodeposited target metal can be peeled off and used again, so that the production cost can be reduced and the overall production efficiency of the smelting operation can be improved. Further, the permanent cathode is characterized in that the verticality of the cathode is better when it is inserted into the electrolytic cell than the cathode of the seed plate used in the conventional seed plate type electrolytic purification or electrowinning.

  In other words, the cathode of the seed plate is manufactured based on the electrodeposited metal plate that has been subjected to the electrodeposition process and the stripping process for producing the seed plate, so that the plate thickness is relatively thin and may be deformed at the time of acquisition. is there. For this reason, as shown in Patent Document 1, the warping of the corner portion is corrected through a pressing process or the like, but it is inevitable that a relatively large strain still remains. On the other hand, the permanent cathode is manufactured on the basis of a commercially available stainless steel plate, etc., so that the plate thickness is relatively thick. Has very good verticality.

  Here, the verticality of the cathode is a quantitative evaluation standard indicating the degree of distortion of the cathode, that is, the degree of bending or warping of the cathode. Specifically, the cathode is suspended by holding its upper end. Sometimes, the strain is evaluated by the absolute value of the difference between the nearest and farthest distance from a vertical reference plane provided facing the cathode. In the case of a permanent cathode used in electrolytic smelting, the perpendicularity of an unused and new cathode is adjusted to within approximately 5 mm. Therefore, the above-described good verticality of the cathode means a flat state in which the entire cathode has very little distortion such as bending and warping, and there is little unevenness on the cathode surface.

  When such a cathode with good verticality is suspended in the electrolytic cell, there is less variation in local distance between adjacent suspended anodes, and the average distance between the anode and the cathode, That is, the distance between the electrodes can be reduced. Furthermore, even if the current density is relatively high, a short circuit between the cathode and the anode is less likely to occur, so that current loss can be reduced and production per unit time can be increased. Moreover, since the surface state of the target metal to be electrodeposited becomes smooth, an electrodeposited metal with good quality can be obtained.

  In this way, the permanent cathode method is superior to the seed plate type cathode in terms of verticality, but if repeated charging into the electrolytic cell and stripping of the electrodeposited target metal are repeated from the outside during charging. There is a case where distortion (plastic deformation) occurs due to the impact of the impact or the bending force received by the stripping device, and the perpendicularity of the permanent cathode gradually deteriorates.

  For example, in the case of a permanent cathode having an approximate size of 1200 mm in length × 1200 mm in width × 3 mm in thickness as shown in FIG. 1 and made of stainless steel or titanium, bending or warping occurs due to repeated use. As shown in FIG. 2, a strain of distance X is generated in the thickness direction of the plate. This distance X is adjusted to be within approximately 5 mm at the start of use, but the strain gradually increases and increases with repeated use. When the distance X exceeds 10 mm, the distance to the adjacent anode becomes very narrow when suspended in the electrolytic cell, so that correction for removing strain is required.

  Permanent cathode strain correction is generally performed by removing the permanent cathode, which is generally judged to be strained, from the operation line and transferring it to the strain correction process. As shown in FIG. 2, the apex of the convex portion corresponding to the peak of the deformation is pushed by a hydraulic cylinder.

JP-A-11-256387 JP 2012-207273 A

  However, when correcting the strain manually using a hammer, a large load is applied locally to the permanent cathode, and the surface of the permanent cathode is often uneven and scratches, and the smoothness of the surface is often impaired. When reused as it is, there has been a problem that the peelability when the electrodeposited metal is peeled off is deteriorated. In addition, the operation of hitting the hammer against the permanent cathode is accompanied by the generation of noise, so it is necessary to wear protective equipment such as earplugs, which has been a factor that deteriorates the working environment.

  Since the distortion correction method of Patent Document 2 is a cathode surface deformation correction method by automatic control, there is no problem of manual work using the hammer described above, but when a permanent cathode is used repeatedly, it is shown in FIG. In addition to the deformation that occurs in the lateral direction from end to end in the lateral direction as described above, convex distortion having the top portion at the substantially central portion of the cathode surface as shown in FIG. 3 begins to occur. And when the height of the convex strain increases, if you try to correct the strain by pushing the top of the convex strain with a hydraulic cylinder, the convex strain will be a so-called jump buckling phenomenon in the middle of the pushing process. In some cases, the strain could not be sufficiently reduced simply by shifting the protruding direction of the convex strain to the opposite side of the cathode surface.

  The present invention has been made to solve such a problem, and can reduce the magnitude of the distortion of the permanent cathode without causing deterioration of the smoothness of the cathode surface and jumping buckling. Another object of the present invention is to provide a device for correcting the distortion of a permanent cathode.

To achieve the above object, the permanent cathode distortion correction apparatus provided by the present invention, a substantially central portion of the cathode surface as the top the cathode surface is fully strained shape convex to bend convexly formed A distortion correcting device for correcting the distortion of the permanent cathode, the suspension means for holding the upper end of the permanent cathode and suspending the permanent cathode; A pushing means for pushing in the convex strain by applying a static load in a direction perpendicular to the cathode surface from the protruding side, and at least two portions sandwiching a portion to which the static load is applied on a surface opposite to the cathode surface to be pushed in in places, provided with a catch means for receiving the permanent cathode of suspended state in the horizontal direction, said pushing means, permanent mosquito suspended state Of the left and right end portions of the cathode surface of the over-de, it is characterized by adding said static load to two places in the same horizontal position as the apex of the convex distortion.

  According to the present invention, it is possible to reduce the magnitude of the distortion of the permanent cathode without impairing the smoothness of the cathode surface of the permanent cathode or causing a jumping buckling phenomenon. The resulting permanent cathode with low distortion and good verticality has less local variation in distance between adjacent anodes when suspended in an electrolytic cell, and therefore between adjacent anodes and cathodes. It is possible to reduce the average distance, i.e., the distance between the electrodes. Furthermore, even if electrolytic purification or electrowinning is performed at a relatively high current density, a short circuit between the cathode and the anode is less likely to occur, so that current loss can be reduced and production per unit time can be increased. Moreover, since the surface state of the target metal to be electrodeposited can be made smooth, an electrodeposited metal with good quality can be obtained.

It is the front view (a) and side view (b) which show typically a permanent cathode without distortion used as a standard. It is the front view (a), side view (b), and perspective view (c) which show typically the permanent cathode which has the linear distortion of an initial stage. It is the perspective view which showed typically the permanent cathode which has the convex distortion | strain which makes the top part the substantially center part which generate | occur | produced as a result of repeated use. It is a typical perspective view after correcting the permanent cathode which has the convex distortion which makes a substantially central part the top using the correction apparatus of this invention. It is the front view (a), side view (b), and perspective view (c) which show one specific example of the distortion correction apparatus of the permanent cathode by this invention. It is the front view (a), a side view (b), and a perspective view (c) which show a mode that the distortion of a permanent cathode is corrected using the distortion correction apparatus of FIG.

  A specific example of the permanent cathode distortion correcting apparatus of the present invention will be described in detail below. In the following description, a convex strain having a top portion of the substantially central portion of the cathode surface as shown in FIG. 3 is formed on a permanent cathode having a length of about 1200 mm × width of 1200 mm × thickness of 3 mm as shown in FIG. In this case, the case where the magnitude of the strain is reduced will be described as an example, but the strain correction device of the present invention is not limited to such a case.

  As shown in FIGS. 5 (a) to 5 (c), the strain correction device 1 according to one specific example of the present invention is a suspension unit that suspends a permanent cathode (not shown) to be corrected by gripping its upper end. 2 has. Specifically, the suspension means 2 includes a substantially triangular frame-shaped suspension portion 2a attached to the movable portion M of the hoist crane, and a rod-shaped engagement portion 2b that respectively hangs from two lower corners. It consists of. The front end of each engaging portion 2b is bent in a U-shape, and an opening formed at the upper end portion of the permanent cathode can be hooked and held at this front end portion. The suspension means 2 can be arbitrarily moved in the vertical and horizontal directions or in the vertical direction with respect to the cathode surface in order to align the suspended permanent cathode, that is, in the vertical and horizontal directions in FIG. 5A. Is preferred.

  The strain correction device 1 according to an embodiment of the present invention further includes a convex strain top formed on the cathode surface of the left and right ends of the cathode surface of the permanent cathode suspended by the suspension means 2 described above. There are pushing means 3 that can be pushed into two specific parts located at substantially the same horizontal position by applying a static load from the side perpendicular to the cathode surface and protruding the convex strain. doing. Specifically, the pushing means 3 is a rod-like member having a length equal to or longer than the distance between the two specific portions described above, and a protrusion is provided at a position corresponding to the two specific portions. The pushing jig 3a, and a hydraulic cylinder 3b that reciprocates the pushing jig 3a in the projecting direction of the projecting part with the projecting part projecting horizontally and the longitudinal direction thereof maintained horizontal. Become.

  The strain correction device 1 according to one specific example of the present invention further includes a permanent at least two locations across the cathode surface portion to which a static load is applied on the surface opposite to the cathode surface pushed by the pushing means 3. Receiving means 4 for receiving the cathode in the horizontal direction is provided. Specifically, the receiving means 4 has a fixed wall portion 4a whose wall surface is fixed in the vertical direction, and has a length equal to or longer than the lateral width of the cathode surface of the permanent cathode, and is horizontally oriented on the wall surface of the fixed wall portion 4a. It consists of the rod-shaped member 4b fixed to.

  The specific length in the longitudinal direction of the rod-like member 4b, the shape and size of the cross section perpendicular to the longitudinal direction, and the number provided on the fixed wall portion 4a are appropriately selected depending on the state of distortion of the permanent cathode to be corrected. That's fine. However, the material of the rod-like member 4b is preferably a material such as wood which is softer than the material of the permanent cathode C so as not to damage the permanent cathode to be received. The rod-shaped member 4b can be installed on the wall surface of the fixed wall 4a by screwing with bolts and nuts, or by joining a sheet-like magnet or the like to the rod-shaped member 4b and using a strong material such as iron. Arbitrary methods such as a magnetic force method for fixing the rod-like member 4b by using a magnetic material and a suspension method using a hook and a rail can be adopted.

  When it is known that the convex shape of the permanent cathode is generated at substantially the same position, a pair of hook-shaped holding portions are attached to both ends of the fixed wall portion 4a in the horizontal direction, and the rod-shaped member 4b is hooked on the two portions. You may do it. As a result, when the rod-like member 4b is damaged due to continuous use or the like and needs to be replaced, it can be easily attached and detached.

  Next, a method for correcting the distortion of the permanent cathode C using the above-described distortion correction apparatus 1 will be described with reference to FIG. First, the engaging portion of the suspension means 2 attached to the movable portion M of the hoist crane is opened at the upper end of the permanent cathode C which has been repeatedly used and has a convex distortion having a top portion at the substantially central portion of the cathode surface. 2b is engaged so that the cathode surface is suspended so as to be substantially perpendicular to the horizontal direction, the cathode surface on the convex side of the convex strain of the permanent cathode C faces the pushing means 3, and is convex. The permanent cathode C is inserted between the pushing jig 3a and the rod-shaped member 4b so that the cathode surface on the concave side of the strain faces the fixed wall portion 4a of the receiving means 4.

  Next, the permanent cathode C in the suspended state by the suspension means 2 is appropriately moved up and down and left and right so that the tip of the cylinder of the hydraulic cylinder 3b is aligned so as to point to the top of the convex strain. As a result, when the push jig 3a attached to the tip of the hydraulic cylinder 3b is advanced toward the permanent cathode C, the protrusions provided at both ends of the push jig 3a are both ends of the permanent cathode C. Can be simultaneously pushed in the thickness direction of the permanent cathode C from the convex side into two locations at the same horizontal position as the top of the convex strain. At this time, it is preferable that the longitudinal direction of the pushing jig 3a is firmly held so as not to incline from the horizontal direction.

  In order to correct the distortion of the permanent cathode C, the permanent cathode C needs to be appropriately plastically deformed. Therefore, when the pushing amount (stroke distance) when pushing the permanent cathode C with the hydraulic cylinder 3b is determined, it is necessary to push in excess by the amount of this spring back in consideration of spring back due to elastic deformation of the permanent cathode. However, if the push-in amount is excessive or the push-in position is inappropriate, the protrusions may jump and buckle, or the strain amount may increase in the opposite direction. It is preferable to set an indentation site. By performing the correction by the above-described method, the permanent cathode having a convex strain with the substantially central portion of the cathode surface as the top before the correction can be corrected as shown in FIG. The permanent cathode shown in FIG. 4 has two corners on the left side of the drawing closer to the reference plane than the general permanent cathode before correction as shown in FIG. It can be seen that the sex has improved.

  In the strain correction device according to one specific example of the present invention, the top of the convex strain among the left and right ends of the cathode surface of the permanent cathode C in which the convex strain having the top at the substantially central portion is formed as described above. The above-described problems such as buckling are less likely to occur because the two parts located at the same horizontal position are pressed perpendicularly to the cathode surface. Here, the left and right end portions of the cathode surface refer to belt-like regions extending from the left and right edges of the cathode surface to the inside of 150 mm, preferably 100 mm, respectively.

  On the other hand, the pushing amount of the hydraulic cylinder 3b may be appropriately determined according to the height of the convex strain generated in the permanent cathode C, the ratio of the convex cylinder to the cathode surface, and the like. In addition to the size of the cathode, it depends on the material, size and thickness of the cathode. Therefore, it is preferable to obtain the relationship between the indentation amount and the strain amount using the same material and the same size as the permanent cathode used in advance. The pushing amount of the hydraulic cylinder 3b in this case can be processed under the same conditions every time by defining the state where the pushing jig 3a is in contact with the cathode surface as 0. Moreover, the accuracy of the correlation between the strain amount and the push-in amount can be improved by accumulating and feeding back correction data having the same shape. Here, the amount of convex strain or the height of convex strain is the vertical plane (reference plane) that passes through the convex side surface of the strain when the permanent cathode is suspended by gripping its upper end. The distance from the top to the top of the convex part.

  When a static load is applied by the hydraulic cylinder 3b, rod-like members 4b that receive the permanent cathode C from the fixed wall portion 4a side are provided at at least two positions sandwiched by the push jig 3a from above and below. Install on the side. Thereby, the permanent cathode C can be pushed in in a so-called three-point bending state. Due to the presence of the rod-like member 4b, two ends of the permanent cathode C pushed by the pushing jig 3a are located at the same horizontal position as the apex of the convex distortion so as to be convex toward the fixed wall 4a. Can be plastically deformed. As a result, even if spring back occurs due to elastic deformation after the load of the hydraulic cylinder 3b is removed, the left and right ends of the permanent cathode C are flatter than before the correction, or are opposite to those before the correction. By forming the convex strain locally, the entire strain of the permanent cathode C can be reduced.

  When the strain is corrected using this apparatus, the hydraulic cylinder 3b is pushed in, the permanent cathode C is sandwiched between the pushing jig 3a and the rod-like member 4b, and the permanent cathode C falls due to the frictional force between these and the permanent cathode C. If the suspension means 2 attached to the hoist crane is slightly lowered and the pushing jig 3a is further pushed in, the upper part of the permanent cathode C can move freely so as not to prevent deformation. It is preferable to do this.

  The total amount of strain can be measured by an optical distance meter installed on the opposite side of the fixed wall 4a from the installation side of the hydraulic cylinder 3b. At the time of measurement, it is preferable that the permanent cathode C is fixed at a predetermined position and the same position on the cathode surface is measured every time. Therefore, a dedicated hook may be used as the suspension means for suspending the permanent cathode C. A measurement hole 5 penetrating in the thickness direction is provided in the fixed wall portion 4a in advance, and a light beam emitted from the optical distance meter is projected onto the cathode surface of the permanent cathode C through the measurement hole 5, and the light beam is projected on the cathode surface. The reflected light is reflected again and detected by the light receiving portion of the optical distance meter through the measurement hole 5. Thereby, the distance between an optical distance meter and the measurement site | part of a cathode surface can be measured.

  Before measuring the distortion amount of the permanent cathode C deformed into a convex shape as described above, it is preferable to measure a flat reference plate with almost no deformation with an optical distance meter and refer to the measurement result of the reference surface. . When the permanent cathode C deformed into a convex shape is measured, the same position on the cathode surface is measured in the same manner, and the difference from the reference surface is obtained, so that the reference surface of the permanent cathode C at an arbitrary position can be obtained. The amount of displacement can be estimated. Further, by measuring each displacement amount on the center line located at the center in the vertical direction of the suspended permanent cathode C, the sectional shape when the suspended permanent cathode C is cut at the center line can be grasped. From this result, the height of the convex shape of the permanent cathode C can be estimated.

  When the height of the convex shape of the permanent cathode C that was the correction target exceeding the control value of 10 mm was measured by the above method, there were many cases where the height was approximately 4 to 6 mm. When the permanent cathode C having a convex height in this range is corrected using the above-described strain correcting device of one embodiment of the present invention, the strain level is reduced to the lowest level without causing jumping buckling. The pushing amount of the hydraulic cylinder 3b that can be reduced to 18 mm was 18 to 21 mm as a result of repeated measurement and simulation.

  As described above, by using the permanent cathode strain correcting device of the present invention, when the convex shape of the central part of the permanent cathode is greatly deformed, the entire convex shape is generated when the convex vertex is pressed. Strain can be reduced without causing transfer buckling. When jump buckling occurs in a convex shape, the amount of strain is often equal to or greater than that before correction, so it is important not to cause jump buckling.

  Further, since the strain correcting device of the present invention corrects strain by a static load, the surface of the permanent cathode is not damaged or the surface roughness is not increased as compared with the case of correcting with a hammer. Therefore, the peelability of the electrodeposited metal is not deteriorated, and the physical and work environment burden on the worker is much smaller than the work using the hammer. In addition, the strain correction device of the present invention has a simple mechanism and is relatively inexpensive as compared with a machine such as a press or a leveler, and can reduce the installation cost and the installation area. Furthermore, since there is little risk of occupational accidents in which a part of the worker's body is caught or caught, there is no need to prepare a special safety device that causes an increase in cost.

(Example)
Strain correction work is performed on 100 stainless steel permanent cathodes having a convex strain having a top at a substantially central portion by repeated use in a copper electrolysis process, using a strain correction device as shown in FIG. did. The permanent cathode before the correction had a convex strain height of 4 to 6 mm, and the strain in the thickness direction was 10 mm or more at the distance X shown in FIG. 1, but after the correction, all the permanent cathodes had the above distance X. It became 7 mm or less. The total man-hours required for correcting the distortion of these 100 permanent cathodes was about 16 hours × person.

[Comparative Example 1]
Strain correction was performed in the same manner as in the above example, except that the conventional strain correction operation was performed while selecting the hammer operation and the press operation according to the state of strain of the permanent cathode. The work man-hours required to correct the strain so that the distance X is 7 mm or less was about 48 hours × person.

[Comparative Example 2]
Strain correction work was performed in the same manner as in the above example except that the pushing jig used for the pushing means was changed to a simple bar-shaped jig longer than the width of the permanent cathode. As a result, 35 out of 100 sheets jumped and buckled. And the distance X could not be made 5 mm or less.

C Permanent cathode 1 Strain correcting device 2 Suspension means 3 Pushing means 4 Receiving means 5 Measuring hole

Claims (3)

The substantially central portion of the cathode surface the cathode surface as the apex is a strain correction device corrects the overall distortion of the permanent cathode convex distortion is formed in a shape bent in a convex shape, the upper end of the permanent cathode A suspension means for gripping and suspending the portion, and applying a static load in a direction perpendicular to the cathode surface from the protruding side of the convex strain so as to improve the overall perpendicularity of the permanent cathode. A pushing means for pushing in; and a receiving means for catching the suspended permanent cathode in a horizontal direction at at least two positions across the portion to which the static load is applied on the surface opposite to the cathode face to be pushed in The pushing means is located at the same horizontal position as the top of the convex strain in the left and right ends of the cathode surface of the suspended permanent cathode. Permanent cathode distortion correction device, characterized in that addition of the static load to two places. Measuring means for measuring a difference from a reference surface when a flat cathode is suspended by irradiating light from a vertical direction to one or more arbitrary positions of the cathode surface of the suspended permanent cathode. The permanent cathode strain correcting device according to claim 1, further comprising a step of determining a distance of pushing by the pushing means based on information obtained by the measuring means. The permanent cathode according to claim 1 or 2 , wherein the suspension means is a hoist crane, the pushing means is a hydraulic cylinder, and the receiving means is a rod-like member supported by a fixed wall portion. Strain correction device.

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