JPH04365887A - Method and device for high-current density electrolysis - Google Patents

Abstract

PURPOSE:To provide the method and device for a high-current density electrolysis which can continuously separate and recover valuable metals, such as gold and platinum groups, and alloys contg. these metals with the reduced cost by a high-current density. CONSTITUTION:Anode metals 4 are supplied to an anode chamber of an electrolytic device and an electrolysis is effected by connecting both electrodes to a conductor with which 1500A/m<2> current is obtainable. The electrodeposited metallic powder deposited on the cathode on progression of the electrolysis is continuously discharged to the outside of an electrolytic cell 3 by an electrolyte 5 forcibly supplied into a cathode box 2. The electrodepositied metallic powder is recovered by filtering the electrolyte 5. The filtrate is supplied into the cathode chamber. On the other hand, the slime formed on the anode is peeled by agitating the anode metals 4 with a scraper 6 and is discharged to the outside of the electrolytic cell 3 by the electrolyte 5 forcibly supplied into the anode chamber. The electrolyte 5 is filtered and solids are sent to a refining stage where the noble metals are recovered. The filtrate is supplied into the anode chamber.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously electrolyzing a metal at a high current density and an electrolyzer used to carry out the method.

0002

[Prior Art] A "continuous electrolyzer for metals" was developed in 1987-9756 as a device for continuous electrolysis at low current density.
0, "Silver electrolytic refining equipment" was published in Japanese Patent Application Laid-Open No. 1-246388.
A "circular electrolytic cell" is disclosed in Japanese Utility Model Application No. 58-97559. Conventionally, expensive metals such as gold and platinum group metals, and alloys containing these metals, have been recovered by the following method using such equipment. A metal plate is made by concentrating precious metals such as platinum in base metals such as copper or lead.
This metal plate is used as an anode to perform electrolysis, depositing electrodeposited metal on the cathode, and generating anode slime containing precious metals on the anode, and after electrolysis is completed, this anode slime is collected from the anode and treated separately. Precious metals were recovered by

In this method, the cathode current density is usually lowered because the aim is to obtain high-quality electrodeposited metal on the cathode.
It was essential to operate within the range of 170 to 260 A/m2, and at the same time, it was also necessary to control the noble metal grade in the anode containing concentrated noble metals to 5,000 ppm or less. Furthermore, as mentioned above, there is a limit to the concentration of precious metals into the anode, making it impossible to continuously discharge the slime. Therefore, in order to recover precious metals on a profitable basis,
It was necessary to increase the number of battery containers, which resulted in a huge initial equipment cost. Furthermore, since the concentration of precious metals is low, there is a technical problem in that the electrolytic life of the anode must be extended, making it difficult to shorten the residence period of precious metals in the battery. As a result, they faced major economic problems such as increased interest rates.

0004

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional technology, and enables continuous separation of expensive metals such as gold, platinum group metals, etc. and alloys containing these at low cost. The purpose is to provide a method and apparatus for high current density electrolysis that can be recovered.

[0005]

[Means for Solving the Problem] As a result of intensive research in order to solve the problem, the present inventors conducted high current density electrolysis using a diaphragm cell, and the products at both electrodes were continuously transported by an electrolytic solution flow. The inventors have discovered that the above object can be achieved by removing the battery from the battery case, and have submitted the present invention.

That is, the present invention separates an anode and a cathode, which are arranged facing each other in a battery case, by a diaphragm, and continuously supplies and discharges an electrolyte to and from the anode chamber and the cathode chamber, respectively. First and second electrolyte flows are created in the chamber, and an anode made of a crude metal for refining is supplied to the anode chamber to conduct electrolysis at a high current density of 500 to 1,500 A/m2, and electrolysis proceeds. The electrodeposited metal powder deposited on the cathode is continuously discharged out of the battery cell by the first electrolyte flow, and the anode slime generated at the anode is continuously discharged out of the battery cell by the second electrolyte flow. 5. A high current density electrolysis method characterized by:
A horizontally arranged anode and a cathode are separated by a diaphragm and are connected to obtain a high current density of 00 to 1,500 A/m2. The present invention provides a high current density electrolyzer characterized by having a battery container configured to supply and discharge an electrolytic solution.

[0007] The method and apparatus of the present invention mainly uses metal shot of base metal containing noble metal with an average particle size of 10 mm or less as the anode supplied to the anode chamber, and recovers the noble metal concentrated in the anode. This is particularly advantageous when used for targeted electrolysis.

[0008]

[Operation] According to the present invention, a metal shot made of a base metal containing a noble metal with an average particle size of 10 mm or less is supplied to the anode chamber using a diaphragm container to serve as an anode, and is continuously and separately placed in the anode and cathode chambers. 500 to 1,500 A by supplying and discharging electrolyte to create an electrolyte flow.
/m2 Electrolytic treatment can be performed efficiently at high current density. By performing electrolysis at high current density in this way,
Because it is possible to generate a large amount of slime containing electrodeposited metal powder on the cathode and precious metals on the anode in a short time, there is no need to increase the number of battery containers, and the battery containers are also smaller, reducing equipment costs. can.

The electrodeposited metal powder deposited on the cathode as described above is discharged outside the battery cell by the electrolyte flow created by the continuous supply and discharge of the electrolyte into the cathode chamber, and the noble metal formed on the anode is After the slime containing the . In this way, by continuously discharging the electrodeposited metal powder deposited on the cathode and the slime generated on the anode out of the tank, it is possible to continue electrolysis for a long time, and the retention period of precious metals in the tank is shortened. As a result, the interest rate will be significantly reduced. Furthermore, in the container portion of the device of the present invention, the cathode and the anode are separated by a diaphragm, so that the granular electrodeposited metal powder and the anode slime do not mix.

[0010] The electrolytic solution containing the electrodeposited metal powder and the electrolytic solution containing the slime discharged to the outside of the battery container are filtered to recover the electrodeposited metal powder and slime. Note that the filtrate obtained during filtration is returned to the battery container again. Further, the collected slime is sent to a refining process to recover precious metals.

[0011] The present invention will now be explained in more detail with reference to Examples. However, the scope of the present invention is not limited by the following examples.

0012

EXAMPLE Pt, Pd, and Rh were separated and recovered from raw materials containing precious metals generated in the automobile industry by a high current density electrolysis method using the apparatus of the present invention shown in FIG.

In the high current density electrolyzer shown in FIG. 1, a Ti-Pt plate 8 serving as an anode is installed as the bottom plate of a battery case 3 of the diaphragm electrolyzer, and a cathode box 2 having a copper plate 7 serving as a cathode serves as an electrode. It is installed at the top of the tank 3 so that both poles are parallel to each other. Further, the anode and the cathode are separated by a diaphragm 1, so that the anode product and the cathode product do not mix. Furthermore, the anode metal 4 (containing a noble metal) is placed in the anode chamber in the anode chamber of the electrolysis device having the above structure, in which the electrolyte 5 can be forcibly supplied and discharged into the anode chamber and the cathode chamber. Copper shot with an average particle size of 10 mm)
high current density electrolysis was performed by connecting both poles with a conductor capable of obtaining a current density of up to 1,500 A/m2. As the electrolysis progressed, electrodeposited metal powder was deposited on the cathode, and slime containing noble metals was generated on the anode. The electrodeposited metal powder deposited on the cathode was discharged out of the container together with the electrolytic solution 5 that was forcibly supplied into the cathode box 2, and the electrolytic solution 5 was filtered and recovered. Note that the filtrate obtained at this time is supplied into the cathode chamber.

On the other hand, the slime generated on the anode was peeled off by stirring the anode metal 4 with a scraper 6, and was discharged to the outside of the battery case together with the electrolyte 5 that was forcibly supplied into the anode chamber. Next, the electrolyte solution 5 taken out was filtered,
The filtrate was supplied into the anode chamber, and the obtained solid was sent to a purification process to recover Pt, Pd, and Rh individually. Note that since the anode metal 4 was a granular metal shot, it was continuously replenished while monitoring the level drop.

[0015]

[Effects of the Invention] With the development of the present invention, the operation of taking the anode in and out is no longer necessary, making it possible to prevent handling loss of precious metals. In addition, it has become possible to downsize the battery case and reduce equipment costs. Furthermore, because the short-life anode can be continuously replenished and the generated slime can be continuously extracted from the system, the retention period of precious metals in the tank is shortened, and the retention rate is significantly reduced. It is now possible to reduce

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a high current density electrolyzer used in performing high current density electrolysis of the present invention.

[Explanation of symbols]

１‥‥‥Diaphragm 2‥‥‥Cathode box ３‥‥‥Battery container ４‥‥‥Anode metal 5‥‥‥Electrolyte ６‥‥‥Scraper 7. Copper plate ８‥‥‥Ti-Pt board

Claims (2)

[Claims] Claim 1: An anode and a cathode, which are arranged facing each other in a battery case, are separated by a diaphragm, and an electrolyte is continuously supplied and discharged to and from the anode chamber and the cathode chamber, respectively. 1 and 2 electrolyte flows are created, an anode made of a crude metal for purification is supplied to the anode chamber, and electrolysis is performed at a high current density of 500 to 1,500 A/m2, and as the electrolysis progresses, the metal is deposited on the cathode. The electrodeposited metal powder is continuously discharged out of the battery case by the first electrolyte flow, and the anode slime generated on the anode is continuously discharged out of the battery case by the second electrolyte flow. Characteristic high current density electrolysis method. 2. An anode and a cathode are separated by a diaphragm and are connected in such a way that a high current density of 500 to 1,500 A/m2 can be obtained and are arranged horizontally, and the anode chamber and the cathode chamber each have an anode and a cathode separated by a diaphragm. 1. A high current density electrolyzer, comprising a container configured to allow separate and continuous supply and discharge of electrolyte.