JP2001181883A - Method for recovering copper in electrolytic refining of copper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method having the reduced equipment cost as a method for recovering copper from the residue generated in the electrolytic refining of copper. SOLUTION: A basket 10 sued in electrolytically refining the residue generated in the refining has a hole 15 through which an electrolyte is passed, holds the residue 1a during the electrolysis, acts as a medium for supplying electricity to the residue 1a, is insoluble in the electrolyte, and replenishes the residue 1a from the top.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrolytic refining of copper, and more particularly to a method of recovering copper from residues of electrolytic refining generated in electrolytic refining of copper.

[0002]

2. Description of the Related Art Methods for electrolyzing metals are roughly classified into two types, one of which is an electrolytic purification method in which a crude metal is used as an anode to deposit and recover a pure metal on a cathode. Yes, the other dissolves the target metal in the electrolyte,
This is an electrowinning method in which the target metal is obtained by electrolysis from this solution using an insoluble anode. In the purification of blister copper, the former electrolytic refining method is generally employed. In this method, the upper part of the blister copper anode cast in the ear mold, which cannot be subjected to electrolysis due to contact with a power source, has a width of about 1 m and a height of about 0.1 m.
About 5m remains. This is called residue, anode scrap, cast-back (hereinafter, the unified name of electrolytic purification residue or residue omitted) is used, and is smelted and processed in the copper recovery process. (Journal of the Japan Society of Resources and Materials “Resources and Materials” (Nonferrous smelting and refining) No. 109 (1993) Nos. 12 and 9
57, FIG. 6 and 965, FIG. 3).

[0003]

As described above, in order to recover copper by smelting the residue, it has been necessary to repeat the process in a converter or cast an anode and perform electrolytic purification again. These methods have the advantage that residues can be processed as they are and that copper with a purity of 99.9% or more can be reliably obtained. However, the method repeated in the converter has a large loss of heat energy, while the anode is cast. In this method, it is necessary to set up a dedicated melting furnace, and there is a problem that the cost of recasting is high because an extra number of molds corresponding to the residues is required.

[0004]

Means for Solving the Problems The electrolytically purified residue has an annual production of 40
A smelter with a production capacity of 10,000 tons produces around 7000 to 10,000 tons. We examined electrolytic refining and electrowinning methods as copper recovery methods that can treat this considerable part.However, electrowinning has the problem that the cell voltage is high. It has been recognized that there is an advantage or loss that it is difficult to recover copper if power cannot be supplied reliably. By further examining these points, in the method of recovering copper from the electrolytically purified residue generated during the electrolytic purification of crude copper, the idea was reached that the electrolytically purified residue was charged into a special basket to perform the electrolytic purification. Was. Specifically, the present invention provides (1) pores through which an electrolyte can pass, (2) residues can be retained during electrolysis, and (3)
It is characterized by (4) being insoluble in the electrolyte and (5) being subjected to electrolytic purification using a cage having an opening capable of replenishing the residue from the top, which acts as a medium for energizing the residue. It is. That is, the basket having these functions (1) to (5) is the basket used in the present invention. As a more preferable function, (6) the basket has a function of discharging the buttocks from the bottom.

[0005] Among the functions of the basket, the first is to move copper ions eluted from blister copper having a purity of about 99% from the hole toward the cathode, take in ions such as sulfuric acid into the basket, and form anode slime. It is embodied as an expanded metal or the like having a diamond-shaped hole formed outside. The second holding function is
It is necessary to retain the residue and expose it to the electrolyte. If residues having the above-mentioned size are to be treated as they are, a correspondingly large size is required, and small-lumpy residues whose size has been reduced by elution during electrolytic purification are placed outside the basket. It is necessary to set the maximum dimension of the hole so as not to move. The third energization function is for ensuring energization via the cage, since direct contact with the residue having an irregular shape makes electrical contact difficult. Therefore, it is preferable that the entire basket is a conductor. The fourth insoluble function is to reduce the electrolytic copper grade to, for example, 99.9.
It is necessary to keep it as high as above. In copper electrolysis, usually using a sulfuric acid bath, titanium is a preferred metal that satisfies this function. The fifth replenishment function is that when the electrolysis is continued, the number of electrical contacts between residues or between the residue and the cage decreases, and the electrolysis voltage rises. It is necessary to prevent the rise. If an opening is provided in the bottom so that the anode slime generated in the electrolytic refining falls into the electrolytic cell from the bottom of the basket, small pieces of blister copper may fall into the electrolytic cell. The anode slime can be moved from the side surface of the basket into the electrolytic cell without providing the plate. The size of the basket is the same as that of the existing anode (for example, 914 to 1216 mm × 1010 to 1155 m).
(mx 42-50 mm) also has the advantage that existing electrolytic refining equipment can be used as it is.

Conventionally, it is known in the field of plating technology to dispose a soluble anode ball in a titanium spiral basket ("Introduction to Mechanical Engineering Series, Introduction to Plating", Rigakusha, July 1993). Published on the 15th, p. 34)
This uses balls of copper or the like to replenish solutes in the plating solution, so the diameter of the balls becomes smaller and the balls fall into the electrolyte from the gap between the wound titanium wires or are pushed out and move into the plating solution. Even so, there is no problem. However, when the blister copper is transferred into the electrolytic solution as a lump, it becomes electrolytic sampling, so the titanium spiral cage used in the plating cannot be used, and the above-described current-carrying function and holding function can be provided. Becomes important.

The method of the present invention can be carried out by either seed plate electrolysis or ordinary electrolysis. However, since the roughness and flatness of the electrodeposited surface of the cathode are slightly inferior to those of the conventional normal electrolysis method, it can be carried out by seed plate electrolysis. preferable. Preferred conditions for electrolytic refining are
CuSO ₄ concentration 180 g / L, Cu concentration 50 g / L, current density 230 A / dm ² , cell voltage 0.6 V, liquid temperature 55-55
At 63 ° C., the distance between the anode and the cathode is 35 mm. The electrolytic refining conditions in the conventional method were such that the cell voltage was 0.3
V, which is the same as that described above, except that the method of the present invention generally has a higher cell voltage than the conventional method,
Others can be carried out under the same conditions as the conventional method. Therefore, when implementing this method in an existing electrolysis plant,
It is desirable to install a dedicated transformer in the tank.

The shape of the electrolytically purified residue is as shown in FIG. 1, where 1 is a residue and 2 is an ear. In order to increase the number of contact points of the residues charged in the basket and to avoid fluctuations in voltage and the like, for example, cut residue 1 with a line indicated by 3 and subject the residue piece 1a to electrolytic purification. Is preferred.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to a front view of a basket shown in FIG. 2, a side view shown in FIG. 3, and a plan view shown in FIG. FIG. 2 shows the lattice plane constituting the basket 10 and the residue pieces 1a inserted into the basket. However, the residue small piece 1a is omitted in the portion where the lattice plane and the like are illustrated, and the residue small piece 1a is omitted.
The lattice plane is omitted in the portion where a is illustrated. The basket 10 is generally formed by joining the outer frame 4, the bottom plate 5, the upper frame 6, and the side baffle plate 9 so that a rectangular space is formed therein,
Further, metal strips 8 intersect so that a lattice plane 7 is formed between these 4, 5, and 6. Such a lattice surface is usually formed by expanding metal, wire mesh, welding of metal strips, etc., but the latter is shown in the figure. The gap 15 surrounded by the metal strips 8 is designed to have a size that allows the electrolyte to pass therethrough but traps the residue small pieces 1 a after elution in the basket 10. The side baffle 9 does not adversely affect the electrolysis efficiency even if the side portion not facing the cathode is closed, and specifies a place where no gap is formed in order to reduce the possibility that the residue small piece 1a goes out of the basket. Is provided. The above-described outer frame 4, bottom plate 5, upper frame 6, metal strip 8, and side baffle 9 are all made of titanium. Reference numeral 11 denotes an auxiliary frame.

As shown in these figures, most of the residue pieces 1a are stacked in the basket so that the width surface 1b (see FIG. 1) faces the front face 10a (see FIG. 3) of the basket. By employing such a charging method, there is no need to excessively shred residues, and the size of the basket can be made substantially the same as that of a conventional anode. Furthermore, as shown
Some of the residue pieces 1a are in contact with each other and some are in contact with any of the members 4, 5, 6, and 8, so the whole is subjected to electrolytic purification. When the electrolytic refining progresses considerably, the size of the residue pieces 1a becomes smaller, the above-mentioned contact is eliminated, and there is a possibility that not a few things floating in the electrolytic solution in the basket 10 may be generated. In such a situation, a new residue piece 1a is additionally loaded from the upper part of the basket 10 shown in FIG. 4, and the residue pieces 1a in the basket are stacked more densely by applying a load, and the contact is restored again. So that

In FIG. 2, reference numeral 20 schematically shows a mechanism for energizing the basket 10 and suspending it in the electrolytic cell.
And a bus bar 21 that bridges between them and connects to a power supply (not shown) by bridging between them. FIG.
3 is a drawing showing the detailed structure of the frame connecting portion 22 as viewed from the same direction as FIG. The upper part is two titanium flat plates 23, 2
4 is arranged so as to be adjustable by a nut / bolt mechanism 25 so that the bus bar 21 (FIG. 2) (not shown) can be firmly held, and the bolt 26 provided below the bus bar 21 ensures the holding of the bus bar 21. .

[0012]

(1) The cost of recasting residues can be reduced. (2) Since the number of repetitions is reduced, the stagnation of the work-in-progress is reduced. (3) Since the residue can be replenished in the basket, there is no need to replace the anode in the tank. As a result, the power outage time is eliminated, so that productivity per tank can be improved. (4) When constructing the electrolytic cell, a device for transporting the residue between the cutting equipment and the electrolytic cell may be considered, which is more efficient than transporting to a melting furnace, a converter, and the like. The transport distance is also short.

[Brief description of the drawings]

FIG. 1 is a view showing residues generated in electrolytic purification of copper.

FIG. 2 is a front view of the basket according to the embodiment of the present invention.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a diagram showing a mechanism for energizing and hanging the basket.

[Explanation of symbols]

 1-Electrolytic refining residue 2-Ear part 3-Cutting line 4-Outer frame 5-Bottom plate 6-Top frame 7-Grating surface 8-Metal strip 10-Cage 20-Electrification and suspension mechanism

Claims (5)

[Claims] 1. A method for recovering copper from electrolytically purified residues generated during electrolytic purification of crude copper, comprising a hole through which an electrolyte can pass, the electrolytically purified residues to be retained during electrolysis, and Copper is characterized by being charged with the electrolytic purification residue and performing electrolytic purification in a basket that is insoluble in the electrolytic solution and can replenish the electrolytic purification residue from above, which is a medium for energization of the electrolytic solution. A method for recovering copper in electrolytic refining. 2. The method for recovering copper in electrolytic copper refining according to claim 1, wherein the electrolytic refining residue cut into small pieces is subjected to electrolytic refining. 3. The method for recovering copper in electrolytic copper refining according to claim 1, wherein the basket insoluble in the electrolytic solution is made of titanium. 4. The method according to claim 1, wherein a seed plate for electrolytic refining is produced by the electrolytic refining.
The method for recovering copper in the electrolytic refining of copper according to the above item. 5. The method for recovering copper in the electrolytic refining of copper according to claim 1, wherein ordinary electrolysis for producing electrolytic copper is performed by the electrolytic refining.