JP6962102B2 - Manufacturing method of anode for electrolytic refining - Google Patents

Description

The present invention relates to a method for producing an anode for electrolytic refining having a lightweight ear portion.

In the electrolytic refining of copper, which is a typical non-ferrous metal, purified blister copper having a purity of about 99.5% obtained by oxidizing and reducing blister copper in a purification furnace is cast into a plate shape, and a substantially rectangular copper plate obtained by this is cast. It is used for an anode (hereinafter referred to as "anode"). For the cathode facing the anode (hereinafter referred to as "cathode"), a thin stainless steel plate is used in the case of the permanent cathode method (PC method), and a rectangle made of high-purity copper is used in the case of the conventional method (seed plate method). A thin plate-shaped seed plate is used.

These anodes and cathodes are immersed in the electrolytic solution stored in the electrolytic cell in a state of being alternately arranged. Then, by applying a predetermined voltage between the anode and the cathode, copper is electrodeposited on the surface of the cathode made of the thin stainless steel plate or the seed plate made of copper. After the electrodeposition is completed, in the case of the PC method, the electrodeposited electrolytic copper is peeled off from a thin stainless steel plate to obtain a product, and in the case of a copper seed plate, the product is shipped in the state of being electrodeposited. On the other hand, the thinned anode is repeated as scrap in the smelting process.

As described above, since the anode is immersed in the electrolytic solution during copper electrolytic refining, as shown in Patent Document 1, the anodes themselves are placed in the upper left and right corners of the rectangular plate-shaped portion immersed in the electrolytic solution. Both ears are formed to project to the left and right to support the. These binaural portions play a role as a support portion during transportation of the anode and during electrolysis, and also serve as an electrical contact point with a so-called bus bar provided at the upper end of the side wall of the electrolytic cell. In this way, since both ears are not immersed in the electrolytic solution, they are not electrolyzed. Therefore, after electrolytic purification of the anode, the smelting process is repeated as scrap together with the thinned rectangular plate-shaped portion. The ratio of the amount of scrap returned to the smelting process to the amount placed in the electrolytic cell is called the scrap ratio. In copper electrorefining, it is required to reduce this scrap rate, which makes it possible to produce electrolytic copper at low cost.

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The scrap rate can be reduced by reducing the weight of both ears, but as mentioned above, the anode is supported by both ears, so if both ears are made too light, the strength will decrease and during transportation. There was a risk that the ears would be greatly deformed during electrolysis and fall to the bottom of the electrolytic cell. Therefore, in the past, there was no choice but to gradually reduce the weight or use the anode of the current shape as it is for fear of the risk of falling, and it is difficult to reduce the weight by combining thinning and thickening at multiple locations. It was not easy to reduce the rate. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for efficiently producing an anode having a weight-reduced ear portion.

In order to achieve the above object, the method for producing an electrolytic purification anode of the present invention is a method for producing an electrolytic purification anode including a rectangular plate-shaped portion and both ears protruding from both left and right corners of the upper portion thereof. Therefore, a stress calculation step of obtaining the stress generated in a plurality of specific parts of the binaural portions when the weight of the anode is applied to the binaural portions by using stress analysis software, and a stress calculation step of obtaining the obtained plurality of specific parts. based on the maximum value among the values of the stress possess the ear shape adjustment step of adjusting the shape of the both ears, the adjustment of the shape of the two ear portions, wherein the maximum value exceeds the predetermined upper limit value If this is the case, overlay processing is performed on the portion showing the maximum value, and if the maximum value is smaller than a predetermined lower limit value, cutting processing is performed on at least the portion showing the minimum value of the stress value. There is.

According to the present invention, it is possible to efficiently reduce the weight of the selvage portion of the anode.

It is a front view of a specific example of an anode produced by the method for manufacturing an anode of the present invention. It is a front view of one ear part of the anode which is the object of the stress analysis performed in embodiment of the manufacturing method of the anode of this invention. It is a front view of one selvage part of the anode of the sample 1 produced in the Example of this invention. It is a front view of one selvage part of the anode of the sample 2 produced in the Example of this invention. It is a photograph which shows the state that the tensile test is performed on one ear part cut out from the anode produced in the Example of this invention.

Hereinafter, embodiments of the anode manufacturing method according to the present invention will be described. The method for manufacturing an anode according to the embodiment of the present invention is to manufacture an anode having both ears that are lightweight based on the result of stress analysis performed using stress analysis software. Specifically, first, general-purpose simulation software capable of performing stress analysis by the finite element method is prepared, and the rectangular plate-shaped portion 1 as shown in FIG. 1 and its upper portion are used as stress analysis targets in this software. The dimensional data of the anode including the binaural portions 2 protruding from the left and right corners to the left and right are input together with the physical property data of the material of the anode such as the specific gravity.

The anode to be stress-analyzed may be the anode used in the electrolytic refining factory or the anode in the design stage. Next, in the electrolytic cell, stress analysis simulation was started assuming that this anode is supported by a horizontally flat portion provided at the lower tip of both ears, and both ears of the anode are started. Calculate the stress generated in each ear when the weight of the anode is evenly applied to the part as a load.

This stress is calculated at a plurality of portions specified in advance in one selvage 2. The plurality of portions are preferably selected from the curved portions of the selvage portion 2. In the present embodiment, as shown in FIG. 2, three parts A1 to A3 that are likely to be damaged such as cracks and cracks are specified from the past results. Specifically, the position of the specific portion A1 is approximately an intermediate point of the lower curved portion 2a of the ear portion 2, and the positions of the specific portions A2 and A3 are both ends of the upper curved portion 2b of the ear portion 2.

As a result of the above simulation, the stress can be obtained for each of these specific parts A1 to A3, so the part having the largest stress value is selected. Then, when the stress value of the selected portion exceeds a predetermined upper limit value, it can be determined that the local load is excessively applied to this portion. Therefore, the strength of the anode can be increased by forming the shape in which the vicinity region including the selected portion is built up. In this case, the vicinity region is preferably a region that covers almost the entire lower curved portion 2a in the case of the portion A1 located in the lower curved portion 2a. On the other hand, in the case of the portion A2 on the tip side of the upper curved portion 2b, a straight line region is formed from the portion A2 to the tip portion of the ear portion 2, and in the case of the portion A3 on the proximal end side with the upper curved portion 2b sandwiched, the upper side is formed. It is preferable that the entire region of the curved portion 2b is a straight region from the portion A3 to the boundary portion 2c between the rectangular plate-shaped portion 1.

The above-mentioned predetermined upper limit value, which is a criterion for determining the necessity of overlaying, can be appropriately determined from the evaluation result by a tensile test described later, and can be used, for example, 30 MN / m ² as a reference. Further, when overlaying, it is preferable to overlay so that the width of the ear portion 2 when the anode is viewed from the front is widened by about 0 to 30%. In this case, the selvage portion 2 may be built up to a uniform degree in the thickness direction, or may be built up gradually toward the surface opposite to the bottom side of the mold when the anode is manufactured. , And vice versa. In the plan view of FIG. 2, the surface that becomes the bottom side of the mold when the anode is manufactured is drawn on the front side of the paper surface, and the anode is drawn toward the bottom side of the mold so that the anode can be easily taken out from the mold. It can be seen that the width of the ear portion 2 is gradually narrowed.

On the other hand, as a result of the above simulation, when the largest value among the stresses of the specific portions A1 to A3 is lower than the predetermined lower limit value, it can be determined that there is an excessive design margin in the selvage portion of the anode. Therefore, by cutting at least in the vicinity region including the specific portion showing the smallest stress value, the weight can be reduced without impairing the substantial strength of the anode. In this case, it is preferable that the neighborhood region is the same as the neighborhood region in the case of overlaying described above. Further, when cutting, it is preferable to cut so that the width of the selvage portion 2 when the anode is viewed from the front is narrowed by about 0 to 30%. In this case, the selvage portion 2 may be cut to a uniform degree in the thickness direction, or may be cut gradually toward the bottom surface of the mold when the anode is manufactured, or vice versa. The above-mentioned predetermined lower limit value, which is a criterion for determining the necessity of cutting, can be appropriately determined from the evaluation result of the tensile test, etc., as in the case of the above-mentioned upper limit value. For example, 20 MN / m ² is used as a reference. Can be used.

For the anode having the shape of both ears that have been built up or cut in this way, the simulation is performed again in the same manner as above, and when the weight of the anode is evenly applied to both ears of the anode as a load, each ear Calculate the stress generated in. Then, it is evaluated whether or not the maximum value of the obtained stress at the specific portion is within the range of the above-mentioned upper limit value and lower limit value. As a result of this evaluation, when the maximum value is within the range of the upper limit value and the lower limit value, it can be determined that a more appropriate selvage shape is obtained.

On the other hand, if the maximum value is still out of the range between the upper limit value and the lower limit value, it is considered that the overlay or cutting is insufficient. , The above-mentioned series of operations consisting of the stress analysis simulation for the selvage having the adjusted selvage shape and the evaluation of the maximum value of the obtained stress, the maximum value is within the range of the upper limit value and the lower limit value. Repeat until you enter. The above series of operations may be repeated until all the stresses of the specific portion calculated by the stress analysis simulation fall within the range of the above upper limit value and the above lower limit value. As a result, the shape of the ear can be optimized in a well-balanced manner.

It is preferable to confirm the actual strength by a tensile test before manufacturing the anode mold so that the anode having the selvage shape whose shape is determined above is formed. Specifically, after actually overlaying or cutting the selvage of the anode so as to have the selvage shape determined above, the elastic deformation limit is used using a tensile tester as shown in FIG. Measure the stress value (proof stress) at the time. Then, the obtained proof stress at the elastic deformation limit adds a predetermined design margin (the size is set in consideration of the acceleration during transportation and mounting) to the load when the anode is supported by both ears. If it exceeds the above, it can be judged that there is no problem in strength and the design is economical. The above tensile test is preferably performed on one selvage portion cut out from the anode, whereby it is not necessary to particularly consider the anode load applied to the selvage portion and its direction, and the handling becomes easy. ..

The stress value when the weight of the anode was applied to both ears of the anode was calculated using SOLIDWORKS (registered trademark), which is a simulation software for stress analysis manufactured by Solidworks Japan Co., Ltd. The dimensions of the anode input to the simulation software used were those actually used in copper electrorefining. Further, the stress value was calculated at the specific sites A1 to A3 shown in FIG.

As a result, the stress at the specific site A1 was 17.8 MN / m ² , the stress at the specific site A2 was 14.2 MN / m ² , and the stress at the specific site A3 was 11.3 MN / m ² . In this case, the stress of the specific site A1 was the largest among the specific sites A1 to A3, and the value was smaller than the ^{reference lower limit value of 20 MN / m 2.} Therefore, as shown by the alternate long and short dash line before cutting in FIG. 3A and the solid line after cutting, the vicinity region including the specific portion A3 having the smallest stress, that is, the upper curved portion 2b and the rectangular plate-shaped portion from the portion A3. In the straight line region up to the boundary portion 2c with 1, a large amount of cutting is gradually made toward the bottom side of the mold on the front side of the paper surface in FIG. The straight part up to was cut a little.

As a result, as shown in FIG. 3 (b), an anode of sample 1 having an ear portion 12 having a gentler inclination in the thickness direction in the vicinity region including the specific portion A3 was prepared. The dimensions of the anode of Sample 1 having the cut ears were input to the simulation software again, and the simulation was performed in the same manner as above. As a result, the stress at the specific site A1 was 20.3 MN / m ² , the stress at the specific site A2 was 14.5 MN / m ² , and the stress at the specific site A3 was 13.5 MN / m ² . From this result, by cutting so that the inclination in the thickness direction becomes gentler in the specific portion A3 and the region in the vicinity thereof, the upper limit value of 30 MN / m ^{2 is obtained not only in the specific portion A3 but also in the specific portion A1 which is the opposite portion.} It can be seen that the stress value increases without exceeding the above, and the design is more economical (that is, the scrap ratio is smaller) than before the cutting process.

Further, with respect to the specific portion A3 and the region in the vicinity thereof, as shown by the alternate long and short dash line before cutting in FIG. 4A and the solid line after cutting, gradually toward the surface opposite to the bottom side of the mold. A large cut was made, and a straight portion from the specific portion A2 to the tip of the ear portion 2 was slightly cut accordingly. As a result, as shown in FIG. 4B, the anode of the sample 2 having the selvage portion 22 having a steeper inclination in the thickness direction in the vicinity region including the specific portion A3 was prepared. When the anode of this sample 2 was simulated again in the same manner as in the above sample 1, the stress at the specific site A1 was 23.4 MN / m ² , the stress at the specific site A2 was 23.1 MN / m ² , and the stress at the specific site A3 was 23.1 MN / m 2. The stress at was 17.3 MN / m ² . From this result, by cutting so that the inclination in the thickness direction becomes steeper in the specific portion A3 and the region in the vicinity thereof, all the stress values of the specific portions A1 to A3 do not exceed the ^{upper limit value of 30 MN / m 2.} It is increasing, and it can be seen that the design is more economical (that is, the scrap rate is smaller) than in the case of the above sample 1.

Next, one ear portion is cut out from each of the sample 1, sample 2, and the anode before cutting, and the anode is charged into the electrolytic cell using a tensile tester as shown in FIG. The stress value at the limit of elastic deformation was measured by applying a force in the direction of the load applied when the bearing was supported by. The measurement results are shown in Table 1 below together with the maximum stress value of A1 among the specific parts A1 to A3 of the simulation results.

From Table 1 above, it can be seen that the stress analysis results by simulation and the tendency of proof stress by the tensile test are in good agreement. Specifically, the rate at which the maximum stress value increases and the rate at which the proof stress decreases are in good agreement, and the actual anode ear is based on the maximum stress value obtained by stress analysis using the above simulation software. It turns out that it is possible to predict the strength.

1 Rectangular plate-shaped part 2 Ear part 2a Lower curved part 2b Upper curved part 2c Boundary part A1 to A3 Specific part

Claims (2)

It is a method of manufacturing an electrolytic purification anode including a rectangular plate-shaped portion and both ears protruding to the left and right from both left and right corners of the upper portion thereof, and when the weight of the anode is applied to both ears, both of them. The shape of both ears is adjusted based on the stress calculation process for determining the stress generated in multiple specific parts of the ears using stress analysis software and the maximum value among the obtained stress values of multiple specific parts. possess a ear shape adjustment step of the adjustment of the shape of both ears is, when the maximum value exceeds the predetermined upper limit value subjected to cladding process at a site indicating the maximum value, the maximum A method for producing an anode for electrolytic purification, which comprises cutting at least a portion showing the minimum value of the stress value when the value is smaller than a predetermined lower limit value. A tensile tester is used on the selvage whose shape of both ears has been adjusted in the selvage shape adjustment step, and various forces are applied to the selvage in the direction when the weight of the selvage is applied to the selvage. Deformation amount measurement process to measure the deformation amount and
Based on the data obtained in the deformation amount measuring step, the proof stress at the elastic deformation limit of the ear portion is obtained, and evaluation is performed to evaluate whether or not the proof stress exceeds the load when the anode is supported by both ears. and further comprising the step, electrolytic method for producing purified for the anode according to claim 1.

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