JP6481887B2 - Anode casting method - Google Patents

Description

  The present invention relates to a technique for producing an anode that is an intermediate product of copper refining. More specifically, the present invention relates to a technique for suppressing “crack” generated in the anode head during casting of the anode.

  In copper refining, an anode is manufactured by casting refined crude copper whose purity is increased to 99.8% in a refining furnace in the anode manufacturing process. The obtained anode is then sent to an electrolysis step, and the anode and a separately prepared cathode are alternately inserted into an electrolytic cell to perform electrolytic treatment, thereby increasing the purity, and electrolytic copper having a purity of 99.99% is obtained. Manufacture.

Quality problems in the anode manufacturing process include anode swelling, casting burrs, picture frames, cracks, and the like. In particular, when a crack having a length of 2/3 or more with respect to the thickness of the anode during anode casting occurs in the thickness direction of the anode head (sometimes referred to as the anode upper part), During the operation, the anode is cut, and if the degree of this crack is large, a serious safety problem occurs such that the anode falls into the electrolytic cell.
Therefore, in order to suppress the occurrence of cracks that are the cause of notches, the strength of the head is ensured by making the anode head thicker than the bottom (sometimes referred to as the anode lower part), and cracks are prevented. Suppressed.

However, since the anode head has a thickness difference between the head and the bottom, when an anode bulge, casting burr, or frame is generated at the anode head, the electrolysis process is the same as when the same is generated at the bottom. The distance between the poles at is made shorter. Shortening the distance between the electrodes induces a short circuit in the electrolysis process and contributes to a decrease in current efficiency.
Therefore, by suppressing the generation of cracks in the anode head, it is possible to manufacture an anode having a uniform thickness, and in order to contribute to the improvement of the operation rate of the electrolysis process, there is currently a technology for suppressing the generation of cracks in the anode head. There is a strong demand.

  Patent Document 1 describes a method of suppressing cracks at the periphery of the anode using different mold release agents having different thermal conductivities. There is no description about the technology for suppressing the generation and the technology for suppressing the generation of cracks in the anode head, and it was not possible to adapt to the suppression of crack generation in the anode head.

JP 2012-183556 A

  In view of such circumstances, an object of the present invention is to provide an anode casting method capable of suppressing the occurrence of cracks in the anode head generated during anode casting using the same mold release agent.

The first invention of the present invention is the casting of the mold formed by being sprayed on the casting surface of the mold during casting of the molten anode into the casting of the anode, which is an intermediate of non-ferrous metal refining using a mold. distribution of spraying concentration of the release agent layer to put that the release agent surface is 10-30% of the anode overall length from the anode upper end except for the anode ear, and 0 from the anode across the anode overall width, respectively, except the anode ears and spraying concentration R _M of the release agent in the release layer of 10% in the range M, 10 to 30% of the anode overall length from the anode upper end except for the anode ears, respectively the anode overall width from the anode both ends and excluding the anode ears of the relationship between scatter density R _N of the release agent in the release layer in the range N excluding the 0-10% range, the distribution of the spraying concentration of the release agent in the release agent layer of R _M> R _N Yes An anode casting method comprising Rukoto.

According to a second aspect of the present invention, the casting of the mold formed by being sprayed on the casting surface of the mold during casting of the molten anode into the casting of the anode , which is an intermediate of non-ferrous metal refining using a mold. distribution of spraying concentration of the release agent layer to put that the release agent surface is 10-30% of the anode overall length from the anode upper end except for the anode ear, and 0 from the anode across the anode overall width, respectively, except the anode ears and spraying concentration R _M of the release agent in the release layer of 10% in the range M, 10 to 30% of the anode overall length from the anode upper end except for the anode ears, respectively the anode overall width from the anode both ends and excluding the anode ears of the relationship between scatter density R _N of the release agent in the release layer in the range N excluding the 0-10% range, the distribution of the spraying concentration of the release agent in the release agent layer of R _M> R _N Yes And said distributing concentration _{R M} is, 0.040 g / cm ³ or more, an anode casting methods, characterized in that less than 0.100 g / cm ^3.

  According to a third aspect of the present invention, there is provided a method for casting an anode, wherein the release agent in the first and second aspects is clay.

A fourth aspect of the present invention, spraying concentration _{R M} in the first to third inventions 0.040 g / cm ³ to less than 0.100 g / cm ^3, and spraying concentration _{R N} is 0.020 g / cm ³ or more and less than 0.040 g / cm ^3, further fifth invention, the release agent which is sprayed in the spraying density _{R M} and _{R N} in the first to fourth inventions, the same type of release agent This is a method for casting an anode.

  According to the anode casting method of the present invention, it is possible to manufacture a high-quality anode in which cracks are not generated in the anode head while suppressing swelling of the anode surface and bending of the shape.

It is a figure which shows the anode casting_mold | template and anode obtained in anode casting, (a) is the schematic which shows the spraying position of the mold release agent in an anode casting_mold | template at the time of anode casting, (b) is explanatory drawing of an anode. It is a figure which shows the evaluation criteria of the crack in an Example.

The present invention is an anode manufacturing method characterized in that the distribution of the spraying concentration of the mold release agent used during anode casting is shaded according to the position of the casting surface of the anode mold.
The inventors have found that the cause of the crack in the anode head is the stress generated by the heat shrinkage strain caused by the difference in cooling rate during casting between the anode root and the side of the anode root. Has been reached.

FIG. 1 is a view showing an anode mold and an obtained anode in anode casting. FIG. 1A is a schematic view showing a spraying position of a release agent in the anode mold during anode casting, and FIG. 1B is an explanatory view of the anode. .
As shown in FIG. 1, in anode casting, in order to satisfactorily form the elongated anode ear 12 of the anode 10, it is necessary to sufficiently pour molten copper into the mold ear 2 of the anode mold 1. Molten copper is poured from an anode head 13 near the anode ear 12.

Therefore, the temperature of the anode head 13 into which the molten copper is poured becomes high, and the anode ridge width 14 _S and the anode ridge top 14 _U are both around the anode body 11, but the temperature of the anode ridge width 14 _S is It becomes lower than the temperature of 14 _U above the anode root. Furthermore, the cooling rate of the anode ridge base 14 _S is faster than that of the anode ridge base 14 _U.

Therefore, in the present invention, when casting the anode, a release agent having a concentration higher than the concentration of the release agent sprayed on the root of the root (range N) is sprayed on the side of the root of the anode mold 1 (range M). In this way, the difference in cooling rate between the anode root top 14 _U and the anode root lateral 14 _S during the cooling of the anode after casting is reduced, and uniform cooling can be obtained to prevent the occurrence of defects.

Specifically, in casting using an anode mold, which is an intermediate of non-ferrous metal refining, the distribution of the concentration of the release agent used by spraying on the casting surface 1a of the anode mold at the time of casting, that 10-30% of the anode overall length from the anode upper end except for the anode ears, and a distribution density R _M of 0-10% range M of the anode overall width respectively from the anode across except the anode ear, ear root on, that is, the 10 to 30% of the total length of the anode from the upper end of the anode excluding the anode ear, and a range N (A _T A _R A _B A A _L excluding a range of 0 to 10% of the total width of the anode from both ends of the anode excluding the anode ear in areas, larger than the spraying concentration R _N range) except the range M, i.e. R _M> casting an anode to an anode mold were sprayed with the release agent so as to satisfy the relation R _N Is shall. The “region surrounded by A _T A _R A _B A _L ” is a range corresponding to the anode main body 11 in a range excluding the mold ear 2 on the casting surface 1a.

Further, the top of the ear root (range N) is a range N ₁ of 0 to 10% of the total length of the anode from the upper end of the anode excluding the anode ear, and 0 to 40% of the total width of the anode from both ends of the anode excluding the anode ear. It is preferable.
Also regardless of the template size that is normally used, the spraying density R _M1 of the release agent in the range M ₁ ear root horizontal 200 mm × 100 mm mold as shown in FIG. 1 (a), ranges else Spread higher than the spraying agent concentration.

  As the mold release agent to be used, the same type of mold release agent as the mold release agent applied to the side of the ear root (range M) and the mold release agent applied to the top of the ear root (range N) are used. If this release agent is different, after the release agent is sprayed on the mold, foaming may occur remarkably at the part where the release agent is mixed, which may cause swelling of the anode. Therefore, the same type of release agent is used. Desirably, the same main component is used, and more preferably a release agent comprising the same component is used.

  As the material for the release agent, it is preferable to use clay, which can smoothly peel the anode from the mold when the anode is peeled from the mold, and is inexpensive.

Spraying concentration of the release agent to be sprayed into the mold, the spraying density _{R M} of the release agent in the ear root lateral (range M) 0.040g / cm ³ or more and less than 0.100 g / cm ^3, in other ranges spraying concentration _{R N} of the release agent is ear root on (range N) is less than 0.020 g / cm ³ or more 0.040 g / cm _^3, it is preferable to satisfy the relation R M> _{R N.}
When spraying the concentration R _M of the release agent in the ear root lateral (range M) is 0.100 g / cm ³ or more, it becomes difficult to cool the anode increases the thickness of the clay layer comprising a heat-insulating layer, stripping the anode At this time, the possibility of causing troubles such as bending of the anode increases.
On the other hand, when the mold release agent concentration R _{M at the} side of the root of the ear (range M) is less than 0.040 g / cm ³ , the difference from the mold release agent concentration of the portion other than the above range becomes small, so the effect of the present invention is achieved. It becomes difficult to obtain.

Except ear root lateral (range M), i.e. spraying concentration R _N of the release agent on the ear root (range N) is, 0.020 g / when cm is less than ^3, the anode is a mold for the layer becomes thin release agent It becomes easy to seize. On the other hand, spraying concentration R _M of the release agent in the ear root lateral (range M) is, in the case of 0.040 g / cm ³ or more, the release agent concentration and the difference between the portion other than the ear root lateral (range) is reduced This makes it difficult to obtain the effects of the present invention.
More preferably, the spray concentration _{R M} of the release agent in the ear root lateral (range M) 0.045g / cm ³ or more and less than 0.096 g / cm ^3, the release agent portion on the ear root (range N) the scatter density _{R N} 0.025g / cm ³ or more and less than 0.030 g / cm ^3.

Further, the range of 10 to 30% of the total length of the anode from the upper end of the anode excluding the anode ear and the range of 0 to 10% of the total width of the anode from both ends of the anode excluding the anode ear (range M), and the anode excluding the anode ear The spraying concentration of the release agent in the range excluding 0 to 10% of the total length of the anode from the upper end and the range of 0 to 40% of the total width of the anode from both ends of the anode excluding the anode ear (range N ₁ ). lower than the spraying concentration _{R M} in, and higher spray density than scatter density _{R N1} ranging _{N 1.}

  Next, it is preferable that the release agent spray nozzle has an angle formed by the nozzle injection surface and the anode mold surface of 30 to 45 °, and the nozzle injection direction faces the bottom of the anode. The reason for the above direction is to prevent the applied release agent from accumulating on the anode mold surface.

Moreover, it is desirable that the dispersal nozzle mounting height of the release agent is 300 to 400 mm from the anode mold surface. By setting it as this attachment height, in the range which spread | released the mold release agent, the variation in the mold release agent layer thickness obtained can be suppressed.
When the distance from the mold surface is less than 300 mm, the nozzle may be clogged by radiant heat from the anode mold. In addition, when the distance from the mold surface exceeds 400 mm, the variation in the concentration of the release agent on the anode mold surface increases.

The present invention will be further described below using examples.
An anode was cast using the anode casting method of the present invention, and cracks generated in the anode head were evaluated according to the criteria shown in FIG. The evaluation results of each example are shown in Table 1.

Clay of the release agent with a clay water dispersed in water, a spray concentration R _M of the release agent to the ear root lateral (range M), ranges excluding the ear root lateral (ear root on: range N) in case of a double spray concentration R _N of the release agent to, specifically, spraying concentration of release agent was sprayed to the ear root beside R _M of 0.050 g / cm ^3, except the ear root lateral ( ear root on: scatter concentration R _N scatter the release agent in the range N) as 0.028 g / cm ^3, provided the release agent layer on the casting surface of the anode mold and cast 100 sheets of the anode (Note unit The amount of release agent sprayed per area is 0.05 g / cm ² ).

Scatter concentration R _M of the release agent to the ear root lateral (range M), ranges excluding ear root Horizontal: When three times the spraying concentration of the release agent to the (ear root on the range N) R _N ( each spray concentration is the concentration unevenness of 0.2 times ± in.), specifically, the spraying density R _M of the release agent was sprayed to the ear root horizontal, 0.090 g / cm ^3, the ear root horizontal except (ear root on: range N) spraying concentration of spraying the mold release agent, _{R N,} a 0.028 g / cm ^3, a release agent layer provided on the anode a mold surface, and casting the 100 sheets of the anode (Note The amount of release agent sprayed per unit area is 0.09 g / cm ² ).

(Comparative Example 1)
The same procedure as in Example 1 was conducted except that the mold release agent concentration was 0.025 to 0.030 g / cm ^{3 and} was sprayed on the entire surface of the mold, and no difference in the mold release agent concentration was given.

(Comparative Example 2)
The same procedure as in Example 2 was conducted except that the mold release agent concentration was 0.025 to 0.030 g / cm ³ and sprayed over the entire surface of the mold, and no difference in the mold release agent concentration was given.

(Conventional example)
In the anode casting mold central spraying concentration 0.090 g / cm ³ clay water release agent, except that sprayed at 0.200 g / cm ³ barium sulphate in the anode casting mold periphery, in the same manner as in Example 1 went.

From Table 1, it can be seen that the occurrence of cracks is suppressed by using the release agent spraying method of the present invention. In particular, it can be seen that it is possible to suppress the occurrence of cracks having a length of 1/3 or more in the thickness direction (cracks of A and B evaluations in FIG. 2), which are the main causes of notches.
Further, in the conventional example, although the occurrence of cracks can be suppressed, the anode has swollen and bent.

1 Anode mold 1a Casting surface (inside the thick broken line)
2 Mold Ear 10 Anode 11 Anode Main Body 12 Anode Ear 13 Anode Head 14 _S Anode Ear Root Side 14 _U Anode Ear Root Top _AT Anode Top (two-dot chain line)
A _B anode lower (two-dot chain line)
_AR anode right end (two-dot chain line)
A _L anode left end (two-dot chain line)
M Range next to the root of the ear (within broken line)
M ₁ Range next to the root of the root (shaded area)
N Range on the root of the ear (A range surrounded by A _T A _R A _B A _L , excluding range M)
N ₁ above the root of the ear (within the chain line)
Spraying concentration of the release agent to spray concentration R _N1 range N ₁ of the release agent to spray concentration of the release agent to spray concentration R _M1 range M ₁ of the release agent to the R _M range M R _N range N

Claims (5)

In the casting of the anode, which is an intermediate of non-ferrous metal refining using a mold, when the molten anode is cast into the mold, the mold is sprayed on the casting surface of the mold and formed on the mold release agent layer of the casting surface of the mold. distribution of spraying concentration of release agent that put is, 10-30% of the anode overall length from the anode upper end except for the anode ears, and an anode both ends except for the anode ears of 0% of the range M of the anode overall width respectively away and spraying concentration R _M of the release agent in the mold material layer, 10-30% of the anode overall length from the anode upper end except for the anode ears, and the range of the anode both ends except for the anode ears of 0% of the anode overall width respectively in relation to the spraying concentration R _N of the release agent in the release layer in the range N excluding,
A method for casting an anode, characterized by having a distribution of a spraying concentration of the release agent in the release agent layer of R _M > R _N. In the casting of the anode , which is an intermediate of non-ferrous metal refining using a mold, when the molten anode is cast into the mold, the mold is sprayed on the casting surface of the mold and formed on the mold release agent layer of the casting surface of the mold. distribution of spraying concentration of release agent that put is, 10-30% of the anode overall length from the anode upper end except for the anode ears, and an anode both ends except for the anode ears of 0% of the range M of the anode overall width respectively away and spraying concentration R _M of the release agent in the mold material layer, 10-30% of the anode overall length from the anode upper end except for the anode ears, and the range of the anode both ends except for the anode ears of 0% of the anode overall width respectively in relation to the spraying concentration R _N of the release agent in the release layer in the range N except having a distribution of spraying concentration of the release agent in the release agent layer of R _M> R _N,
And said distributing concentration _{R M} is, 0.040 g / cm ³ or more, the anode casting methods, characterized in that less than 0.100 g / cm ^3.   3. The method for casting an anode according to claim 1, wherein the releasing agent is clay. Said distributing concentration _{R M} is 0.040 g / cm ³ or more, 0.100 g / cm less than ^3,
And said distributing concentration _{R N} is 0.020 g / cm ³ or more, the anode casting methods according to any one of claims 1 to 3 and less than 0.040 g / cm ^3. It said distributing concentration R _M and a release agent which is sprayed in R _N is, the anode casting methods according to any one of claims 1 to 4, characterized in that the same type of release agent.