AU2011219212B2

AU2011219212B2 - Copper electrorefining equipment and copper electrorefining method using the same

Info

Publication number: AU2011219212B2
Application number: AU2011219212A
Authority: AU
Inventors: Kenichi Kawaguchi; Makoto Narita; Kimihiro Shimokawa; Tatsuya Wada
Original assignee: Pan Pacific Copper Co Ltd
Current assignee: Pan Pacific Copper Co Ltd
Priority date: 2010-02-23
Filing date: 2011-01-24
Publication date: 2012-11-22
Anticipated expiration: 2031-01-24
Also published as: KR101351105B1; WO2011105149A1; KR20120020130A; JP5275273B2; JP2011174113A; CL2012002253A1; AU2011219212A1

Abstract

Disclosed are an electrolytic copper refining device, and an electrolytic copper refining method using the same, which are capable of producing high-quality electrolytic copper at low manufacturing cost. The electrolytic copper refining device (10) is provided with a copper electrolysis tank (17), an electrolyte supply unit (11) for supplying an electrolyte to the electrolysis tank (17), an additive tank (12) for supplying an additive containing thiourea and hydrochloric acid to the electrolyte supply unit (11), and a gelatin solution tank (13) for continuously supplying to the electrolyte supply unit (11) an aqueous solution of gelatin produced by continuously dissolving continuously supplied gelatin.

Description

COPPER ELECTROREFINING EQUIPMENT AND COPPER ELECTROREFINING METHOD USING THE SAME TECHNICAL FIELD OF THE INVENTION (0001) The present invention relates to a copper electrorefining equipment and a copper electrorefining method using the same. BACKGROUND OF THE INVENTION (0002) In a copper electrorefining, glue is generally added in electrolyte to be supplied to an electrolytic bath-in order to improve appearance of a surface of an electrolytic copper (for example, patent document 1 or 2). In addition to the glue, thiourea and hydrochloric acid are added in the electrolyte for improving the appearance of the surface of the electrolytic copper, further, sulfuric acid is added in the electrolyte for preventing corrosion of the glue. (0003) Figure 2 indicates a schematic diagram of conventional general copper electrorefining equipment 20. The conventional copper electrorefining equipment 20 is equipped with electrolytic bath 27, electrolyte supply part 21 which supplies electrolyte to the electrolytic bath 27, additive bath 22 which includes additives to be supplied to the electrolyte supply part 21, glue dissolution bath 23 in which glue solution to be supplied to the additive bath 22 is prepared, thiourea dissolution bath 24 in which thiourea to be supplied to the additive bath 22 is provided, hydrochloric acid bath 25 in which hydrochloric acid to be supplied to the additive bath 22 is provided, sulfuric acid bath 26 in which sulfuric acid to be supplied to the additive bath 22 is provided, and pumps p'l-p'6 each of which is located between each of those baths. In the electrorefining equipment 20, the glue is firstly made into aqueous solution in the glue dissolution bath 23, and then mixed with additives of thiourea, hydrochloric acid and sulfuric acid in the additive bath 22 in which those additives are provided. Thus, additive solution is prepared in the additive bath 22, and then supplied to the electrolyte supply part 21. Next, the electrolyte containing the additive solution is supplied from the electrolyte supply part 21 to the electrolytic bath 27. When the glue solution is prepared in the glue dissolution bath 23, measurement of the glue and an input operation to the glue dissolution bath 23 are conducted by humans in predetermined operation time (generally, once in a day), using batch process. Further, the preparation of the additive solution is conducted with the same frequency. (0004) (Patent documents 1) Japanese Patent No.4041571 (Patent documents 2) Japanese Patent Application Laid-open Publication No.2005-307343 SUMMARY OF THE INVENTION (0005) However, when the glue solution is mixed in the additive solution, the additive solution contains hydrochloric acid and sulfuric acid, and therefore the glue, which is animal protein and high-molecular substance, is decomposed to be low-molecular-weight by those acids. Further, when the glue is added singularly to the electrolyte supply part in neutral solution without being mixed with hydrochloric acid and sulfuric acid, the glue has a property of being corrosion prone. (0006) Thus, when the glue being converted into a low-molecular-weight compound by the acids or the corroded glue is added to the electrolyte, quality deteriorations, of poor product appearance and increase of impure elements, are produced because of deterioration of glue effect to the electrolytic copper. Further, when an additive amount of glue is increased in order to avoid the effect of the acid decomposition or the corroded glue for maintaining a grade of the electrolytic copper, an electrolyte resistance is increased by the glue being added excessively in the electrolyte. Accordingly, high applied electric pressure is needed and it causes a problem of increase of electric requirements. (0007) Therefore, the present invention aims to provide a copper electrorefining equipment and a copper electrorefining method using the same, wherein excellent graded electrolytic copper can be produced at lower production costs. (0008) The inventor has diligently studied to cope with the requirements, and eventually have found out that degradation by acid can be inhibited, fresh glue aqueous solution of macromolecular state can be added in the electrolyte and excellent graded electrolytic copper can be produced at good production cost, by adding glue to the electrolyte supply part separately from other additives, without mixing with acid, and conducting each process of measurement, dissolution and addition of glue in succession. (0009) In one aspect, the present invention that has been made based on these findings is a copper electrorefining equipment comprising: a copper electrolytic bath, an electrolyte supply part supplying electrolyte to the electrolytic bath, an additive bath supplying additives except glue to the electrolyte supply part, and a glue dissolution bath, continuously supplying glue aqueous solution produced by continuously dissolving glue, to the electrolyte supply part. (0010) In an embodiment, the present invention is the copper electrorefining equipment further comprising a glue supply part, continuously supplying the glue to the glue dissolution bath. (0011) In another embodiment, the present invention is the copper electrorefining equipment wherein the additives except glue include thiourea and hydrochloric acid. (0012) In another aspect, the present invention is a method for copper electrorefining comprising: a step for supplying additives except glue to an electrolyte supply part, a step for continuously dissolving the glue at electrorefining copper and then continuously supplying the dissolved glue to the electrolyte supply part, and a step for supplying electrolyte, including the additives except glue and the glue aqueous solution, from the electrolyte supply part to an copper electrolytic bath. (0013) In an embodiment, the present invention is the method for copper electrorefining wherein measurement of the glue, being employed at producing the glue aqueous solution, is conducted in succession at the same time as the continuous glue supply and the continuous glue dissolution. ADVANTAGEOUS EFFECT OF THE INVENTION (0014) The present invention can add glue to an electrolyte supply part without mixing with acid, separately from other additives, and conduct each step of measurement, dissolution, and addition of glue in succession. As the result, degradation by acid can be inhibited, fresh glue aqueous solution of macromolecular state can be added to electrolyte and then electrolytic copper having excellent grade can be produced. Further, the present invention relates to a copper electrorefining equipment and a method using the same, which can add glue in macromolecular state, and therefore it is not necessary to add glue excessively. Accordingly, it contributes to lower power consumption. Further, it contributes to lower production cost because it is not necessary to use sulfuric acid that has been heretofore used for corrosion prevention of glue. BRIEF DESCRIPTION OF THE FIGURES (0015) Fig. 1 is a schematic diagram of a copper electrorefining equipment of the present invention. Fig.2 is a schematic diagram of a conventional copper electrorefining equipment. PREFERRED EMBODIMENT OF THE INVENTION (0016) (Copper electrorefining equipment) Copper electrorefining equipment 10 comprises copper electrolytic bath 17, electrolyte supply part 11, additive bath 12, glue dissolution bath 13, thiourea dissolution bath 14, hydrochloric acid bath 15 and glue supply part 16. Pumps p1-p5, which are supply engines for solution, are provided between electrolyte supply part 11 and additive bath 12, between electrolyte supply part 11 and glue dissolution 13, between additive bath 12 and thiourea dissolution bath 14, between additive bath 12 and hydrochloric acid bath 15 or between electrolyte supply part 11 and electrolytic bath 17.

(0017) Additive bath 12 includes thiourea aqueous solution, which is supplied from thiourea dissolution bath 14 by pump p3, and hydrochloric acid, which is supplied from hydrochloric acid bath 15 by pump p4. (0018) Glue supply part 16 cuts off stored glue after measurement, and then supplies it to glue dissolution bath 13. Glue dissolution bath 13 includes glue aqueous solution, which is made by combining glue supplied from glue supply part 16 and heated water from heated water supply part (not shown). (0019) Electrolyte supply part 11 includes electrolyte, glue aqueous solution, which is supplied from glue dissolution bath 13 by pump p2, and additive solution, which is supplied from additive bath 12 by pump pl. Additive solution consists of hydrochloric acid including thiourea. (0020) Crude copper constituting anode, and mother plate made of copper, constituting cathode, to purify electrolytic copper which becomes product by electrodepositing copper on an electrodeposition surface thereof, are provided with electrolytic bath 17, at prescribed intervals. Further, electrolyte is supplied from electrolyte supply part 11 to electrolytic bath 17 by pump p5. Various sorts of materials may be used for mother plate constituting cathode, depending on the intended use. For example, in the case of conducting electrolysis by Permanent Cathode (PC) method, SUS plate and the like may be used for mother plate. (002 1) (Copper electrorefining method) Next, copper electrorefining method using copper electrorefining equipment 10 is explained below. At first, in copper electrorefining equipment 10 described in Fig.1, thiourea aqueous solution of prescribed concentration is prepared in thiourea dissolution bath 14. In addition, hydrochloric acid of prescribed concentration is prepared in hydrochloric acid bath 15. Next, thiourea aqueous solution and hydrochloric acid are supplied to additive bath 12 by pumps p3 and p4, and then agitated and mixed.

(0022) Next, hydrochloric acid, including thiourea in additive bath 12, is supplied to electrolyte supply part 11 by pump p1. The supply of hydrochloric acid including thiourea, from additive bath 12 to electrolyte supply part 11, may be conducted in batch type. That is, for example, a day's amount of thiourea aqueous solution and hydrochloric acid may be mixed at a time and stored in additive bath 12, and then may be supplied to electrolyte supply part 11. Further, the supply may be in continuous type. That is, thiourea aqueous solution and hydrochloric acid may be mixed in additive bath 12 in succession, and then requisite amount thereof may be supplied to electrolyte supply part 11. (0023) On the other hand, glue supply part 16 cuts off stored glue after measurement, and then continuously supplies it to glue dissolution bath 13. Heated water from heated water supply part (not shown) is also continuously supplied to glue dissolution bath 13. The supplied glue is agitated with the heated water in glue dissolution bath 13 and is dissolved in about 10 minutes, and then glue aqueous solution is produced. In succession with this, glue aqueous solution is supplied to electrolyte supply part 11 by pump p2. Further, at this time, measurement of glue by glue supply part 16 may be conducted in succession at the same time as supply of glue, dissolution of glue in glue dissolution bath 13 and supply of glue aqueous solution from glue dissolution bath 13 to electrolyte supply part 11. (0024) hydrochloric acid including thiourea, supplied from additive bath 12, and glue aqueous solution, continuously supplied from glue dissolution bath 13, are agitated and mixed with electrolyte in electrolyte supply part 11. Next, electrolyte including thiourea, hydrochloric acid and glue, is supplied from electrolyte supply part 11 to electrolytic bath 17 by pump p5, and then copper electrorefining is conducted in electrolytic bath 17 by using the electrolyte. (0025) As described above, in the present invention, the glue aqueous solution is prepared by continuously dissolving glue, which is continuously supplied from glue supply part 16, in glue dissolution bath 13, and then the glue aqueous solution is continuously supplied to electrolyte supply part 11. In this way, the dissolved glue is directly supplied to electrolyte supply part 11, without being mixed with hydrochloric acid in additive bath 12. Accordingly, glue is not decomposed by acid and then glue can be used efficiently. Further, it is not necessary to supply sulfuric acid for glue corrosion prevention to additive bath 12. Accordingly, a production cost becomes lower. In addition, continuously supplied glue is continuously dissolved and then continuously supplied to electrolyte supply part 11. Accordingly, a time, when glue is dissolved in water until it is supplied to electrolyte supply part 11, is short, and then corrosion of glue can be inhibited. Therefore, electrolytic copper having excellent grade can be provided. Further, measurement of glue, being employed at producing glue aqueous solution, is conducted at the same time as continuous supply of glue and continuous dissolution of glue in succession. Therefore, production cost thereof can be lower. EXAMPLES (0026) Hereinafter, working examples of the present invention will be described. However, these examples are described in order to understand the present invention better and therefore the present invention is not limited to these examples. (0027) (Working example) As working example, copper electrorefining equipment, in which a structure thereof is described in Fig. 1, was prepared and copper electrorefining was conducted by using it. In particular, at first, 54 plates of crude copper of 1060mm(length) x 990mm(width) x 45mm(thickness), and 53 mother plates of 1040mm(length) x 1040mm(width) x 10mm(thickness), were provided each other at intervals of 100mm in electrolytic bath of 1280mm(length) x 5550mm(width) x 1340mm(depth). Next, 0.83mol/L of thiourea aqueous solution was provided in thiourea dissolution bath, and 9.6mol/L of hydrochloric acid was provided in hydrochloric acid bath.

Next, thiourea aqueous solution and hydrochloric acid were supplied to additive bath, and then agitated and mixed. Solution temperature in the additive bath was kept at 20 to 30 0 C. Thus, hydrochloric acid including thiourea in the additive bath was prepared and stored in advance, and then requisite amount thereof was supplied to electrolyte supply part. In glue supply part, stored glue was cut off after measurement, and then continuously supplied to glue dissolution bath while heated water was also continuously supplied from heated water supply part to the glue dissolution bath. The supplied glue was agitated with the heated water in the glue dissolution bath and then dissolved in about 10 minutes. At this time, the glue aqueous solution was prepared so that concentration thereof is 0.5mmol. Next, the produced glue aqueous solution was continuously supplied to the electrolyte supply part. Solution temperature in the glue dissolution bath was kept at 35 to 45 0 C. Next, in the electrolyte supply part, hydrochloric acid, including thiourea from additive bath, and the glue aqueous solution, continuously supplied from the glue dissolution bath, were agitated and mixed with the electrolyte. Next, the electrolyte, including thiourea, hydrochloric acid and glue, was supplied from the electrolyte supply part to the electrolytic bath. Next, copper electrorefining with the electrolyte was conducted at 320A/m 2 of current density in electrolytic bath for 210 hours. By the above example, 6350 ton of electrolytic copper was provided. Used amount of glue, required to the example, was 350kg, and amount of consumed power was 370kWh. (0028) (Comparative example) As comparative example, copper electrorefining equipment, in which a structure thereof is described in Fig.2, was prepared and copper electrorefining was conducted by using it. In particular, at first, 54 plates of crude copper of 1060mm(length) x 990mm(width) x 45mm(thickness), and 53 mother plates of 1040mm(length) x 1040mm(width) x 10mm(thickness), were provided each other at intervals of 100mm in electrolytic bath of 1280mm(length) x 5550mm(width) x 1340mm(depth).

Next, 3mmol/L of glue aqueous solution was provided in glue dissolution bath, 0.85mol/L of thiourea aqueous solution was provided in thiourea dissolution bath, 10.Omol/L of hydrochloric acid was provided in hydrochloric acid bath and 1O.Omol/L of sulfuric acid was provided in sulfuric acid bath. Next, glue aqueous solution, thiourea aqueous solution, hydrochloric acid and sulfuric acid were supplied to additive bath, and then agitated and mixed. Solution temperature in the additive bath was kept at 20 to 30*C. Thus, glue aqueous solution, thiourea aqueous solution, hydrochloric acid and sulfuric acid in the additive bath were prepared and stored in advance, and then requisite amount thereof was supplied to electrolyte supply part. Next, in the electrolyte supply part, mixed solution of glue aqueous solution, thiourea aqueous solution, hydrochloric acid and sulfuric acid from the additive bath was agitated and mixed with the electrolyte. Next, the electrolyte, including glue, thiourea, hydrochloric acid and sulfuric acid, was supplied from the electrolyte supply part to the electrolytic bath. The copper electrorefining with the electrolyte was conducted at 320A/m 2 of current density in electrolytic bath for 210 hours. By the above comparative example, 6350 ton of electrolytic copper was provided. Used amount of glue, required to the comparative example, was 410kg, and amount of consumed power was 378kWh. (0029) Explanation of letters or numerals in drawings 10 electrorefining equipment 11 electrolyte supply part 12 additive bath 13 glue dissolution bath 14 thiourea dissolution bath 15 hydrochloric acid bath 16 glue supply part 17 electrolytic bath pl-p5 pump

Claims

1. A copper electrorefining equipment comprising: a copper electrolytic bath, an electrolyte supply part supplying electrolyte to the electrolytic bath, an additive bath supplying additives except glue to the electrolyte supply part, and a glue dissolution bath, continuously supplying glue aqueous solution produced by continuously dissolving glue, to the electrolyte supply part.

2. The copper electrorefining equipment of claim 1, further comprising a glue supply part, continuously supplying the glue to the glue dissolution bath.

3. The copper electrorefining equipment of claim 1 or 2, wherein the additives except glue include thiourea and hydrochloric acid.

4. A method for copper electrorefining comprising: a step for supplying additives except glue to an electrolyte supply part, a step for continuously dissolving the glue at electrorefining copper and then continuously supplying the dissolved glue to the electrolyte supply part, and a step for supplying electrolyte, including the additives except glue and the glue aqueous solution, from the electrolyte supply part to an copper electrolytic bath.

5. The method for copper electrorefining of claim 4, wherein measurement of the glue, being employed at producing the glue aqueous solution, is conducted in succession at the same time as the continuous glue supply and the continuous glue dissolution. 1/