FI121411B - Anode casting method and casting device for copper anodes - Google Patents

Description

A method of casting an anode and a device for casting an anode of copper

BACKGROUND OF THE INVENTION 1. TECHNICAL FIELD The present invention relates to a method and apparatus for selecting an anode. More specifically, the present invention relates to a process for casting both a valuable metal and a copper alloy (hereinafter referred to simply as "melt") into a mold to produce an anode plate for electrolytic purification and a method for casting an anode plate.

10 2. Description of Related Techniques

The crude copper obtained by smelting is subjected to an anode furnace for oxidation and reduction to produce approximately 99.5% pure crude copper. This refined crude copper is cast into a mold. An example of a conventional mold is shown in Figures 7 (a) and (b), respectively, corresponding to the top view and the side view, respectively. The rectangular plate-shaped recess portion 103a is adjacent to a pair of shoulder portions 103c. The back surface of the mold 103 is shown by reference numeral 103b. The melt is molded and the "anode" thus formed is subjected to electrolytic purification.

Generally, purified copper is drained from a pair of anode furnaces and passed through a trough to a bucket where the purified copper is once stored. The purified crude copper is then drained into a dosing bucket equipped with a weighing cell with a weighing function.

Referring to Figure 8, a conventional anode casting device is shown. Twenty-mold, which is schematically indicated by the reference numeral 3 (i) through 3 (20) C., 25 are arranged circumferentially on a turntable 1 which is rotated during the treatments described under the direction of the arrow.

Pouring the melt into the serving bucket 10 is continued until a predetermined amount, for example 350 kg, has been weighed. A predetermined amount of melt is poured into the mold 3 (1), 3 (2), 3 (3), ... 3 (20) during rotation of the rotary table 1. The molds 3 (3) to 3 (n) are cooled in the water cooling zone 5. It is evident that the other molds are successively introduced into the cooling zone 5 by a rotating table 1. The cooling water is sprayed into the molds 3 and the melt solidifies in molds 3. The cooled and solidified melt (is) and the anode thus obtained is subjected to an electrolytic purification process.

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A release agent, such as clay powder, is applied to the inner surface of the mold 3 (i6), where the anode has been removed. Then, silicone is applied to the inner surface of mold 3. The melt is again cast into mold 3 (i), which has been subjected to the release agent and silicone application as described above. The anode casting operation is continued as described above until the anode furnaces are emptied.

In the meantime, the anode quality is examined after cooling to detect, for example, bending or distortion of the anode, which causes uneven deposition of copper on the cathode plate during electrolytic purification. Such unsuitable anode is removed from the mold 3 <13> and is not subjected to an electrolytic purification process.

In the anode casting apparatus shown in Fig. 8, it is presumably important to cool the molded anode in the mold to a suitable temperature from the point of view of forming an excellent shape of the anode in Japanese Unexamined Patent Application (cocaine) no. 7-32090 (hereinafter referred to as "Patent Publication Γ) 15. Patent 1 therefore proposes a method of cooling the anode wherein the difference between the melt casting temperature and the anode surface temperature is set at 300 ° C at the anode lift point. This is where one anode begins to be raised. In addition, the spraying of cooling water onto the anode and the mold is effected to the extent that the temperature of the anode surface is reduced to 650 ° C or lower at the end of the water cooling.

JP 2003205354 A discloses an apparatus and method for making copper anodes by casting. The publication discloses a rotary table 1, a mold 2, an anode 2a, the nozzle cooling water 7, the nozzles 7a of the mold underside of injecting a stowed ni n7, the nozzles 7b of the mold upper side 25 for injecting a stowed n8-Ni 3, and the anode release means 9. The publication discloses the simultaneous mold and cooling the anode therein from above and below. The publication does not disclose the implementation of the refrigerator.

Description of the Invention

Recently, an additional improvement in the casting efficiency of the anode has been required in addition to 30 to improve from a conventional level of 80 t / h to a level of 120 t / h. To achieve such a requirement, the rotary table 1 must rotate at a higher speed. The cooling capacity of the cooling zone is insufficient to meet the required level and thus the temperature of the cooled molds 3 is higher than the conventional level.

35 The temperature of the mold into which the melt is to be cast should be 160 ° C or lower during the summer time and 140 ° C or lower during the winter period from the point of view of keeping the mold temperature as low as possible. When the melt is poured into the mold, the mold touches the melt on its inner surface and the spray water on its outer surface. Therefore, a temperature difference is created across the mold and can cause heat shrinkage on the mold casting surface. Fracture defects may form on the inside of the mold.

5 The above-mentioned low temperature difference seems to increase mold life.

Referring to Figure 5, the temperature of each of the twenty molds 3 is shown in ordinate. The number of several molds is shown in the drawing for brevity. Treatments are presented in abscissa. Note that the second cooling is not carried out in the conventional anode casting method, but in the kek-10 casting method described below. The curve ♦ - ♦ indicates the temperature of the mold in a conventional anode casting machine operated at a level of 120 t / h raised to a level higher than a conventional level of 80 t / h.

The temperature of the mold 1 (1), i.e. the mold at the point of injection, is 185 ° C. This temperature is so high that the anode size varies unfavorably, the mold 15 breaks or breaks unfavorably, shortening the mold life. In addition, the anode adheres to the mold. To prevent the above drawbacks, the cooling region 5 can be enhanced. However, this enhanced cooling can cause deformation, fractures and the like in the mold. Even if the known cooling methods described in Patent Document 1 are used, the casting efficiency of the anode cannot be improved.

Summary of the Invention

Thus, it is an object of the present invention to provide a casting method and apparatus which can eliminate the drawbacks described above. More particularly, it is an object of the present invention to provide an anode casting method and a ku-25 anode casting device which can produce an anode-free anode and does not reduce the life of the mold in a high casting device.

For purposes of the present invention, there is provided a cu-anode casting device by casting a melt into a mold comprising: a rotary table having a plurality of circumferential molds for casting the anode; en-30 first-order cooling means to cool the molten casting and solidify it into anodes; temperature measuring means for measuring the temperature of the mold or molds from which the anodes have been removed; second cooling means for cooling molds from which the anodes have been removed; and a temperature control unit that defines a condition for cooling the molds to a predetermined thermal state based on the measured temperature and which controls the second cooling means.

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According to the copper anode casting device of the present invention, the anode which is cooled by the first cooling means is removed from the mold and subsequently the temperature of the mold is measured by temperature measuring means. The measured temperature is further reduced in the second cooling means. This device is controlled by a temperature-5 wire control unit. Even when the rotary table is operated at high speed, the temperature of the mold into which the melt is cast is not increased and the temperature of the molds can be maintained at a suitable level. Therefore, the casting efficiency of the anode can be increased.

According to an embodiment of the present invention, the second cooled means water-cools the bottom and / or sides of the mold, from which the anode has been removed. The heat removal of the mold is improved by further cooling the bottom and / or side sides.

In accordance with a further embodiment of the present invention, the temperature control unit controls the second cooling means in that it cools the temperature of the deflected anode and returned to the casting position as the rotary table rotates. Namely, the temperature of the molding mold is controlled to be 160 ° C or lower in the first rotation cycle and 180 ° C or lower in the second and subsequent rotation cycles. The melt is therefore molded into a mold having a temperature of 160 ° C or less in the second casting and molded into a mold having a temperature of 180 ° C or less in the third and subsequent castings. The temperature of the mold which is led into the cooling zone is therefore relatively low and is further cooled in the cooling zone. Correspondingly, the temperature of the mold at the outlet of the anode also becomes relatively low. Thus, the overall temperature rise of the recyclable molds is counteracted as the molds circulate through the respective regions. Therefore, the casting efficiency of the anode can be increased.

According to yet another embodiment of the present invention, the lower surface of the mold is corrugated or provided with cooling fins. As a result, the lower surface area of the mold is increased so that the cooling efficiency is increased. Therefore, the temperature rise of the molds can be further attenuated during the recycling of the molds.

For purposes of the present invention, there is provided an anode casting method wherein the melt is cast into a plurality of circumferentially molded table molds thereby forming an anode, the method comprising: first cooling the melt cast into the mold thereby solidifying the melt and forming the anode; a step of removing the anode from one of the molds; a step for measuring the temperature of the anode removed from the mold; a cooling step of the second, anodized, mold; and a temperature control step for determining the required condition to cool from the measured temperature to a predetermined temperature.

According to an embodiment of the casting method of the present invention, the second cooling step comprises water cooling the mold from the side and / or bottom sides.

The mold side and / or bottom sides are water-cooled by spraying water during the second cooling so that the casting mold temperature is 10 160 ° C or lower in the second molten molding, i.e. after the first recycle, and 180 ° C or lower in the second and subsequent molding after.

In accordance with the method and apparatus of casting the anode of the present invention, the anode is cooled by first cooling means and then the anode 15 is removed from the mold. Next, the temperature of the mold is measured. The cooling conditions from the measured temperature to the predetermined temperature are determined based on the measured temperature. This cooling is effected by other cooling means. Thus, although the rotational table speed is increased, the temperature of the mold into which the melt is cast is not increased and can be maintained at a suitable level. Therefore, the casting efficiency of the anode 20 can be increased.

Brief Description of the Drawings

Fig. 1 is a top view showing an embodiment of an anode casting device in accordance with the present invention.

Figure 2 illustrates an example of a temperature measurement method and Figures 2 (a) and (b) show a top plan view and a cross-sectional view of the mold, respectively, along line A-A.

Figure 3 schematically shows other cooling means.

Figures 4 (a) and (b) are a top view and a side view respectively of a mold.

Figure 5 is a graph showing temperature changes in the mold used in the anode casting device or conventional anode casting device of the present invention.

Fig. 6 is a flowchart according to an embodiment of the anode casting method of the present invention.

Figures 7 (a) and (b) are a top view and a side view 35 of a conventional mold, respectively.

Fig. 8 is a top view showing a conventional anode casting device.

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Description of Preferred Embodiments

The anode casting method and apparatus of the present invention is illustrated in more detail with reference to Figures 1-6.

Referring to Figure 1, an embodiment of the anode casting apparatus according to the present invention is illustrated. The same parts of the casting device and the conventional casting device shown in Figure 8 are shown with the same reference numerals.

The anode casting apparatus A shown in Figure 1 generally comprises a rotary table 1, a first cooling region 5, a thermometer 20a, a second cooling means 21, and a temperature control unit 20 for controlling the second cooling means 21.

Twenty molds 3 (i) - (20) are circumferentially mounted on the rotatable table 1, for example for casting a copper anode. The number of molds is not limited to twenty. The rotary table 1 is rotated in the direction of the arrow is not shown drive mechanism. The melt is molded into mold 3 <i) and other molds as they are rotated to the position indicated by 3 (i}).

A predetermined amount, for example about 350 kg, is flushed into the dosing bucket 10 and the completion of the dripping is monitored by a weighing cell in the dosing bucket 10. The serving bucket 10 is then inclined to drain the melt into mold 3 (i).

Referring to Fig. 4, a mold 3 is shown which is concave from the ground-shaped anode-shaped recess 3a into which the melt is cast. The mold 3 is aided from the back surface 3b to increase the surface area and thus the cooling efficiency. Although not shown in Figure 4, the rear surface 3b may be provided with cooling fins to increase cooling efficiency.

Again, with reference to Figure 1, the rotary table 1 is provided with a first cooling region 5 at the molds 3 (3Hii). The first cooling region 5 is provided with a canopy 6 covering the rotating table 1 at the molds 3 (3) (11). The canopy 6 is provided with nozzles 7 (iH9) for spraying cooling water, which nozzles are connected to a water pipe not shown. The nozzles 7 (1) (5) cool the molds 3 (3) (7) but do not directly cool the metal in these molds 30 from above in order to avoid the formation of a solidified surface on the top surface of the melt in these molds. The solidified surface of copper forms a stain on the surface of the anode and exerts an unfavorable effect on the electrolytic cleaning process. In the meantime, the nozzles 7 (8) to (9) cool the molds 3 (iohh) and also cool the metal cast directly into these molds.

35 The anode in mold 1 (i3) following the first cooling region 5 is removed from this mold if abnormalities such as bending, twisting or the like are detected and the removed and unsuitable anode is reused as a cooling material in the converter or the like. The acceptable anode is removed from the mold 3 (15) and then subjected to the next electrolytic purification process.

A thermometer 20a is positioned at the mold 3 (i6) to measure the temperature of this mold. As a thermometer 20a, a radiation pyrometer can be used to measure the surface temperature of the mold. For example, a non-contact thermometer commercially available as Sensytherm IR-P manufactured by Hartmann & Braun Corporation may be used. The Touch Thermometer, too, is a front-10 hand calibrated with a touch type thermometer, such as the AP-300 under the trade name of Anritsu Co., Ltd.

Referring to Figures 2 (a) and (b), the mold temperature is measured, for example, at step 3c on one side of the mold. This point 3c is about 120 mm from the bottom up and about 550 mm from the center to the right. The temperature-15 data measured in step 3c is led to a temperature control unit 20 described below.

Referring again to Figure 1, the release agent application device 31 is disposed at the mold 3 (16) and places a release agent consisting of clay and the like in the mold.

The temperature measuring means 20 is provided with a program that calculates the following 20 steps. Namely, the second cooling means 21 described below reduce the temperature (Ti) measured by the thermometer 20a to the required temperature (T2) of the mold, which is returned to step 3 (i) after one rotation of the rotatable table 1. The required temperature (T2) is preferably 160 ° C or less, or 180 ° C or less, as described above. The heat-25 space measuring means 20 is also provided with a central unit that controls cooling to achieve the desired temperature of the molds.

The mold temperature (TO) measured at mold 3 (i6), where the anode is removed, does not increase significantly despite the added casting efficiency. This again results in a lowering of 30 (i) _ (20o) of the rotating molds 3 to the rotating table 1. rotation speed and hence casting efficiency.

The second cooling means is disposed at the mold 3 (i7). COOL other dytysvälineisiin 21 includes a cover which covers a mold 3 (I7), and the spray nozzle 21a (Figure 3) of the mold 3 (I7) and the spray nozzles to cool the underside 21 b of the mold 35 3 (17) for cooling the lateral sides. These jet nozzles 21a and 21b are located inside the canopy and are connected to a cooling water line (not shown). The underside of the mold 8 3 (17) is cooled by cooling water from the jet nozzle 21a, while the sides of the mold 3 (17) are cooled by water from the jet nozzles 21b. The jet nozzles 21a and 21b are electrically connected to the temperature control unit 20 by electromagnetic valves (not shown) which are opened or closed by an electrical signal from the thermal state control unit 20. The solenoid valves are open until the amount of cooling water calculated by the temperature control unit 20 over time and the total amount of cooling water is supplied to the spray nozzles 21a and 21b.

The cooling water can be supplied from any jet nozzle 21a 10 or 21b. Further, it is desirable that no spraying of cooling water from above the mold 3 (i7) is carried out, since the cooling water remains unevaporated on the mold 3 (i7> when pouring the melt and may cause a water-vapor explosion. 3 (i>.

The silicone adjusting device 30 is disposed on the mold 3 (ΐβ). The silicone adjusting device 30 is disposed on the edge of the mold 3 (18) to reduce the trace that may be referred to as a picture frame.

1-4, the anode casting device shown above was used to cast the anodes according to the same casting conditions and rotational speeds as the conventional casting method illustrated in Fig. 5 by ♦. This means that the casting efficiency is 120 t / h. The temperature of each mold was measured with a portable radiation pyrometer, commercially available under the trade name IR-TE, manufactured by CHINO Corporation. The measured temperature change is shown in the curve - χ in Figure 5. The temperature of the mold 3 (i), namely the free mold into which the melt is poured, is about 140 ° C. This result indicates that a casting operation of 120 / t is possible, which is 50% higher than the standard efficiency of 80 / h. With a casting efficiency of 120 t / h in the conventional anode casting process, the mold lifetime is 1600 anode casting, while the mold 3 lifetime is strikingly raised to as high as 5,000 anode casting.

The anode casting method of the present invention is described below with reference to the movements of the anode casting device of the present invention.

First, the dosing scoop 10 weighs a predetermined amount of melt. The flow of the melt from the furnace (not shown) to the serving bucket 10 is then stopped 35 and the melt is poured into the mold 3 (i) on the rotary table 1.

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The mold 3 (1) is conveyed to the first cooling zone 5 by rotating the rotary table 1 and the spray nozzles 7 (1) (9) spray cooling water into the molds 3 (3hh) (see step S1 shown in Figure 6). After the completion of the first cooling, the anodes are inspected for evaluation of acceptability or error. The defective anode is removed from the mold 3 (i3) and reused as a cooling material or the like. The acceptable anode is removed from the mold 3 (i5) and subjected to electrolytic cleaning. The thermometer 20a measures the temperature (Ti) of the mold 3 (16) with the anode removed (step S2). The thermal state data is supplied to the temperature control unit 20. This unit 20 calculates the second cooling condition 10 in the second cooling zone 21 with respect to the amount of cooling water required to lower the mold 3 (ie> T1) to the required temperature (T2) of the mold or after two or more cyclic rotations Unit 20 determines the spray time (step S3) In this case, one or more of the plurality of spray jets 15 can be stopped, or the spray rate of each nozzle can be adjusted.

The nozzle 21a for spraying cooling water to the underside of the mold 3 and the nozzles 21b for spraying cooling water to the lateral sides of the mold 3 are controlled based on the calculation results of step (3). These nozzles 21a and 21b are opened and closed under control and cool the mold (step 4). The underside of the mold is corrugated to increase the surface area and to reduce the cooling time to less than the conventional mold cooling time.

After completing the cooling in the second cooling zone 21, the mold 3 is returned to the casting site and receives 25 melts. The casting operation described above is repeated until the anode furnaces have been emptied of all melt.

Claims (6)

A copper anode molding device by casting a melt in a mold comprising: a rotating table, on which are arranged peripherally several molds to form copper anodes and first cooling means to cool the melt molded into the molds, characterized by the casting device further comprising: temperature measuring means for measuring the temperature of the mold, from which form the copper anode has been removed; other coolers for cooling the molds from which the copper anodes have been removed; and a temperature control unit which determines the cooling ratio for cooling the molds to a predetermined temperature based on measured temperature and which controls the other cooling devices. Anode casting device according to claim 1, characterized in that the other coolants water-cool one or both of the bottom and flank sides of the mold. Anode casting device according to claim 1 or 2, characterized in that the temperature of the mold on the casting rack is regulated such that it is 160 ° C or lower during the first rotation period and 180 ° C or lower during the second and subsequent rotation periods. 4. Anode casting device according to any of claims 1-3, characterized in that the mold is corrugated on its lower surface. Anode casting method, in which the melt is molded in a number of circumferentially arranged shapes on a rotating table, thereby forming an anode, the process comprising a first cooling step of the melt cast in the mold thus causing the melt to solidify and forming an anode and removing the anode from one of the molds, characterized in that the method further comprises: a step of measuring the temperature of the mold from which the anode has been removed; a second step of cooling the mold from which the anode has been removed, from the measured temperature to a predetermined temperature; and a temperature control step for determining the required behavior to cool from the measured temperature to a predetermined temperature. Anode casting method according to claim 5, characterized in that the temperature of the mold on the casting rack is controlled so that it is 160 ° C or lower during the first rotation period and 180 ° C or lower during the second and subsequent rotational periods.