JP2896764B2 - Casting method of anode for copper electrolysis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates also relates to a casting how the anode copper electrolysis in copper smelting process, especially the quality improvement of the anode, due life extension of the mold, MOVE operation of a copper smelting process, about the casting how the anode copper electrolyte that enables stabilization of the electrolysis operation.

[0002]

2. Description of the Related Art Electrolytic copper is obtained by refining blister copper obtained by dissolving copper ore in a converter and a refining furnace, casting the resulting purified blister copper as an anode plate for copper electrolytic refining, and obtaining the obtained copper. An anode plate for electrolytic refining (hereinafter referred to as an anode for copper electrolysis or an anode) and a cathode plate as a seed plate are alternately charged into an electrolytic cell at regular intervals, electrolyzed, and further purified with respect to the purified crude copper. It is obtained by depositing electrolytic copper on the seed plate.

In this case, an anode casting facility for copper electrolysis is:
Generally, as shown in FIG. 2, a plurality of molds (hereinafter, referred to as master molds) 12 which are co-mold molds made of copper are placed on a turntable 11 which is a mold conveying means. The master is continuously transported while rotating the turntable 11, and the molten copper is cast into the master. That is, the copper quality obtained in the refining furnace, which is the final step of copper smelting, is about 99.4%.
% Of purified blister copper is poured into a casting facility 13, weighed to a predetermined weight, and cast into a matrix 12.

[0004] The cast anode is then cooled.
After being sprayed with water and solidified by cooling, it is pushed up from the bottom of the matrix 12 by a push-up rod, peeled off, and inserted into the cooling tank 15. The master mold 12 from which the anode has been stripped is sprayed with an aqueous solution of the release agent by the release agent application equipment 16 in preparation for the next casting.

As an aqueous solution of the release agent, a slurry in which clay powder is dissolved in water is used. The slurry release agent is dried on a high-temperature matrix 12 (about 130 ° C.). A refractory film is formed to improve the peelability of the anode cast in the matrix 12. However, the clay powder in the release agent that has been conventionally used has poor adhesion to the matrix and conversely easily adheres to the anode, and thus adheres to the anode and separates from the matrix. There is a problem in that the amount of the release agent remaining and retained decreases, and the amount of the release agent required for repair increases.

Further, in the case of the conventional release agent, there is a difference in the thickness of the release agent depending on the position on the matrix, and a trouble occurs in which the anode is seized on the matrix at a portion where the film thickness becomes small. On the other hand, the high-temperature molten metal comes into direct contact with the matrix, which causes severe damage to the matrix.When copper is cast with the damaged matrix, the resulting anode surface has irregularities, such as unevenness. Is remarkably deteriorated, and the following problems occur in the post-process.

[0007] That is, if a poor quality anode having an uneven surface is used in the subsequent electrolysis step, the number of short circuits increases and the current efficiency increases due to contact between electrodes and uneven local distance between adjacent electrode surfaces. There was a problem that the reduction of the temperature occurred. Further, when the above-mentioned anode to which the clay powder is attached is used, there is a problem that slime increases in the electrolysis step.

Other release agents that have been conventionally used include barium sulfate, which adheres to the anode surface in the same manner as clay powder, and requires cleaning when used in the anode electrolysis step. It was more expensive than clay powder and had problems in terms of economy.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, enhances the adhesion between the mold release agent and the matrix, improves the quality of the anode, prolongs the life of the mold, and improves the quality of the mold. It is possible to reduce the amount of mold agent, and an object thereof is to provide a MOVE operation, casting how the anode copper electrolysis stabilization of the electrolytic operation is achieved.

[0010]

DISCLOSURE OF THE INVENTION The present invention relates to an anode for copper electrolysis, in which an aqueous solution of a mold release agent for casting is applied to a mold, dried, then molten copper is poured, and a cast copper product after cooling and solidification is removed from the mold. Casting method, wherein the aqueous solution of the release agent for casting is
A method for casting an anode for copper electrolysis, characterized by using a mixed aqueous solution containing clay powder and water glass at a concentration of earth powder = 4 to 8 wt% and water glass = 0.3 to 0.8 vol%. .

[0011]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The present inventors have conducted intensive studies to solve the above-described problems of the prior art, and as a result, regarding the casting of an anode for copper electrolysis in a copper smelting process, as a mold release agent aqueous solution of the anode cast in the matrix, Clay powder = 4-8 wt%, water glass = 0.3
By using a mixed aqueous solution containing clay powder and water glass at a concentration of ~ 0.8vol%, the quality of the anode is improved, the life of the mold is extended, the operation of cast copper, the electrolytic operation is stabilized, and the use of a mold release agent It has been found that the amount can be reduced.

FIG. 1 shows the state of the release agent remaining on the matrix and the state of retention when the mold is pushed up from the bottom surface of the mold by the push-up rod after the anode casting in the case of applying the present invention and in the case of the conventional method. This is schematically shown in a sectional view. In FIG. 1, (a) shows the case where the present invention is applied, (b) shows the case of the conventional method, 1 is an anode, 2 is a matrix, 3 is a mold release agent, 4 is a push-up rod, and 5 is a push-up rod. Indicates the direction of movement of.

That is, in the case of the conventionally used clay powder, the adhesion between the mold release agent 3 and the matrix 2 is poor, and the difference in the film thickness of the mold release agent remaining and retained depending on the position on the matrix. However, by using the aqueous solution of the release agent according to the present invention, the adhesion between the release agent and the matrix was improved, and the release agent was able to uniformly remain and be retained in the matrix. In the present invention, for example, clay powder and water glass are dissolved in water in the tank of the release agent coating equipment 16 of the anode casting equipment for copper electrolysis shown in FIG. Apply to.

The application method in this case is exemplified by a spraying method, but the application method is not limited. The amount of clay powder and water glass added to water is preferably as a concentration in the mixed aqueous solution, preferably clay powder = 4 to 8 wt%, water glass = 0.3 to 0.8 vol%, more preferably clay powder = 5 to 5 vol%.
6 wt%, water glass = 0.5 to 0.6 vol%.

When the concentration of the clay powder is less than 4% by weight, the frequency of seizure of the anode to the matrix increases, the quality of the anode deteriorates, and the damage of the matrix increases. On the other hand, if the concentration of the clay powder exceeds 8 wt%, the effect of preventing the seizure of the anode on the master mold is practically saturated, and the clay powder is wasted, which is not economical. On the other hand, when the concentration of the water glass is less than 0.3 vol%, the action of the water glass as a binder of the clay is not exhibited, and the adhesion of the release agent to the matrix decreases, and conversely, 0.8 vol%
If it exceeds, the release agent adheres to the anode, the surface properties of the anode deteriorate, and the anode needs to be cleaned when used in the electrolytic process.

The water glass used in the present invention is preferably a concentrated aqueous solution of silicon dioxide-alkali glass obtained by melting silicon dioxide and alkali represented by the following composition, and is a colorless, highly viscous liquid having tackiness. Then, if left in the air, it dries and becomes glassy. (Composition of water glass :) M ₂ O · nSiO ₂ (n = 2 to 4) (M: an alkali metal selected from Na, K, etc.), moisture: 10 to 30 wt% In the present invention, the water glass Depending on the characteristics,
After applying the release agent aqueous solution to the mother mold, the water glass is rapidly dried by the high temperature mother mold (about 130 ° C), and the water glass serves as a binder to form a strong clay film on the surface of the mother mold. However, it is considered that the adhesion between the release agent and the matrix is improved.

In the above-described mold release agent application equipment 16 of FIG. 2, the mold 12 after the aqueous solution of the mold release agent according to the present invention has been applied and the mold release agent has dried is transferred to the casting equipment 13 by the turntable 11. Conveyed, molten copper as refined crude copper is poured into the matrix 12. The molten copper poured into the mold 12 is cooled and solidified by the cooling equipment 14, and the cast copper product after the cooling and solidification is pushed up from the bottom of the mold 12 by a push-up rod, peeled off and inserted into the cooling tank 15, and Is produced.

[0019] Having described the process of casting the anode copper electrolysis, the release agent solution for die casting molten copper engagement Ru in the present invention, preferably, the difference between the melting point of the mold and the molten copper is small, It is used as a release agent aqueous solution for molten copper casting using a mold in which seizure easily occurs, and more preferably, a so-called co-mold mold in which the material of the mold is substantially the same as the molten copper. It is preferably used as an aqueous solution of a release agent for casting molten copper .

The amount of clay powder and water glass added to water in the aqueous release agent solution is preferably 4 to 8% by weight of clay powder and 0.3% of water glass as the concentration in the mixed aqueous solution.
0.80.8 vol%, more preferably clay powder = 5-6 wt%, water glass = 0.5-0.6 vol%. When the concentration of the clay powder is less than 4% by weight, the frequency of seizure of the anode to the matrix increases, the quality of the anode deteriorates, and the damage of the matrix increases.

Conversely, if the concentration of the clay powder exceeds 8% by weight, the effect of preventing the seizure of the anode on the master mold is practically saturated, and the clay powder is wasted, which is not economical. On the other hand, when the concentration of the water glass is less than 0.3 vol%, the action of the water glass as a binder of the clay is not exhibited, and the adhesion of the release agent to the matrix decreases, and conversely, 0.8 vol% If it exceeds, the release agent adheres to the product, and the surface properties of the product deteriorate.

Aqueous release agent for molten copper mold casting according to the present invention
As the water glass used in the liquid , water glass having the above-described composition is preferably used.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. (Example) A casting experiment of an anode for copper electrolysis was performed using the casting facility shown in FIG. A release agent aqueous solution, which is a mixed aqueous solution of clay powder = 5 wt% and water glass (composition: sodium silicate) = 0.5 vol%, was sprayed onto the mold 12 on the turntable 11 from the release agent application equipment 16.

The matrix 12 is a common mold made of purified crude copper. The mold 12 after applying the aqueous solution of the mold release agent in the mold release agent application equipment 16 and drying the mold release agent is transported to the casting equipment 13 by the turntable 11 and the purified copper Was poured. The molten copper poured into the mold 12 is cooled and solidified by the cooling equipment 14, and the cast and solidified copper product after the cooling and solidification is pushed up from the bottom of the mold 12 by a push-up rod, peeled off, and inserted into a cooling bath 15 to be used as an anode for copper electrolysis. Was manufactured.

Table 1 shows the amount of the release agent used (basic unit), the life of the matrix (the number of castings), the number of shorts in the electrolysis process, the amount of slime treated, and the incidence of defective anodes in this experiment. (Comparative Example) A casting experiment of an anode for copper electrolysis was performed in the same manner as in the above example, except that water glass was not added and an aqueous solution of a release agent that was an aqueous solution of clay powder = 8 wt% was used. .

Table 1 shows the amount of the release agent used (basic unit), the life of the matrix (the number of castings), the number of shorts in the electrolysis process, the amount of slime treated, and the incidence of defective anodes in the experiment. The results are shown together with the results of the examples. As shown in Table 1, according to the present invention, the adhesion between the release agent and the matrix was greatly enhanced, and the following excellent effects were obtained.

(1) The amount of the release agent used was reduced by about 85%. (2) The strong release agent film formed on the mold works as a heat insulating material, preventing damage to the mold and allowing the number of anode castings per mold to increase significantly by about 37%. . (3) A smooth master surface was maintained, and the quality of the anode was improved. As a result, the number of short circuits in the electrolysis process was reduced by 27%.

(4) The amount of the release agent attached to the anode was reduced, and the amount of slime treated in the electrolysis process was reduced by about 17%. (5) As a result of reduced seizure, the incidence of defective anodes
Decreased by 0.9%.

[0029]

[Table 1]

[0030]

As described above, according to the present invention, the adhesion between the mold release agent and the matrix is greatly enhanced, and the mold release agent that has adhered to the anode side can be uniformly formed on the matrix. It has remained and can be retained. Therefore, the following excellent effects were obtained, and the operation of cast copper and the operation of electrolysis were stabilized.

(1) The amount of the release agent used can be greatly reduced. (2) The strong release agent film formed on the matrix worked as a heat insulating material, preventing damage to the matrix and extending the life of the matrix significantly. (3) The quality of the anode was improved by maintaining a smooth matrix surface, and as a result, the number of short circuits in the electrolysis process could be significantly reduced.

(4) The amount of the release agent attached to the anode was reduced, and the amount of slime treated in the electrolysis step was reduced. (5) As a result of the reduction in image sticking, the incidence of defective anodes decreased. (6) By the addition of water glass, the uniform dispersibility of the clay powder in the mixed aqueous solution is improved, and a stable slurry concentration is obtained,
As a result, a release agent film having a uniform thickness can be obtained.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a cross-sectional view schematically showing a state in which a release agent remains and remains in a matrix. FIG. 1A shows a case where the present invention is applied, and FIG. 1B shows a case where a conventional method is used.

FIG. 2 is a plan view showing an anode casting facility for copper electrolysis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode 2, 12 Mold (base mold) 3 Release agent 4 Push-up rod 5 Moving direction of push-up rod 11 Turntable 13 Casting equipment 14 Cooling equipment 15 Cooling tank 16 Release agent application equipment

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI C10M 103: 06) C10N 40:36 (56) References JP-A-55-133843 (JP, A) JP-A-3-447 ( JP, A) JP-A-4-178238 (JP, A) JP-A-9-267151 (JP, A) JP-A-61-269955 (JP, A) JP-A-63-60043 (JP, A) Hei 6-5756 (JP, U) Japan Copper and Brass Association [Fundamentals of Copper and Copper Alloys (Revised)] Editorial Committee, "Fundamentals of Copper and Copper Alloys (Revised)", (Heisei 6-10-31) , Japan Copper and Brass Association p. 61-63 Japan Foundry Association, “Casting Handbook”, 4th revised edition, (61-1-20), Maruzen, p. 958-967 (58) Field surveyed (Int. Cl. ⁶ , DB name) B22D 25/04

Claims (1)

(57) [Claims] 1. A method for casting an anode for copper electrolysis, comprising applying an aqueous solution of a mold release agent for casting to a mold, drying the solution, pouring molten copper, and taking out the cast copper product after cooling and solidifying from the mold. As a mold release agent aqueous solution for casting , clay powder = 4 to 8 wt%, water
A method for casting an anode for copper electrolysis, comprising using a mixed aqueous solution containing clay powder and water glass at a concentration of 0.3 to 0.8 vol% .