JPH10219363A - Method for recovering metal in solution and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently recover metal as powdery material in a short time even from solution dissolving the metal to be recovered in low concn. by utilizing replacing reaction of the metal and to continuously recover the metal without stopping the replacing reaction, in a method and a device for recovering the metal from the solution dissolving noble metal, etc. SOLUTION: This recovering device is constituted with a packing tower 1, a stirring machine 2 arranged in the packing tower 1 and a recovered metal receiving vessel 4 arranged below the bottom surface 3 of this packing tower 1, and the solution A dissolving the metal to be recovered is passed through and brought into contact with metallic grain 9 having baser than the metal to be recovered or grain group 8 mixing the base metallic grain with electric conductive grain 10. At the time of recovering by depositing the metal to be recovered on the surface of the grain group 8, the metal to be recovered, deposited on the surface of the grain group 8 is dropped from the surface by stirring the grain group 8 and mutually rubbing and recovered and also, the surface of the grain group 8 is always held to active.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for recovering a metal to be recovered from a solution in which the metal to be recovered is dissolved by using a substitution reaction. In time, it can be recovered as a powder,
The present invention relates to a method and an apparatus for recovering metals in a solution, which can be continuously recovered without stopping the reaction.

[0002]

2. Description of the Related Art Various waste liquids such as silver cyanide plating solutions contain a large amount of useful metals such as noble metals dissolved in the form of ions or complex salts. In recent years, various techniques for recovering metals from these solutions have been developed. ing.

[0003] As this type of recovery technique, conventionally, an electrolysis method, an ion exchange method, an activated carbon adsorption method, a substitution method with a base metal, and the like have been generally used.

[0004]

However, in the above-described electrolysis method, when the concentration of the metal dissolved in the solution is low, the current efficiency is extremely low, so that the time required for recovery is long. I will. Further, since the recovered metal adheres to the electrode, it is necessary to remove the electrode from the electrolytic cell and recover the metal from the electrode surface.

In addition, the ion exchange method and the activated carbon adsorption method have a small amount of metal exchange per unit volume of the ion exchange resin and activated carbon used in them, and are therefore unsuitable for high concentration solutions. In addition, the processing speed is slow, so that the equipment becomes very large, and when it is saturated, a large amount of ion exchange resin or activated carbon must be replaced, resulting in expensive expenses.

Further, in the replacement method using a base metal, the base metal to be recovered is covered with the deposited recovered metal, and the reaction stops. For this reason, powdered zinc is usually used as a base metal, but since it is a powdered metal, the reaction is intense and it has been difficult to implement a device.

Therefore, an object of the present invention is to utilize the above-mentioned metal substitution reaction to efficiently and quickly recover a powder from a solution in which the metal to be recovered is dissolved at a low concentration, In addition, it is an object of the present invention to provide a method and an apparatus for recovering a metal in a solution, which can be continuously recovered without stopping the substitution reaction and which has improved the drawbacks of the above-mentioned known technique.

[0008]

In order to achieve the above-mentioned object, according to the method of the present invention, a solution in which a metal to be recovered is dissolved is passed through and brought into contact with particles of a metal which is more noble than the metal. In collecting and recovering the metal to be recovered on the surface of the particle group, by rubbing the particle group with each other,
The method is characterized in that the metal to be recovered deposited on the surface of the particle group is collected by dropping from the surface, and the surface of the particle group is always kept active.

Further, in order to achieve the above-mentioned object, according to the apparatus of the present invention, a packed tower, a stirrer arranged in the packed tower, and a collected metal receiving tank installed below the bottom of the packed tower are provided. The packed tower is provided with at least an inlet for a solution in which the metal to be recovered is dissolved, and is filled with particles of a metal that is more noble than the metal to be recovered. A solution in which the metal to be recovered introduced from is dissolved and brought into contact with the stirrer while stirring to precipitate the metal to be recovered in the solution on the surface of the particle group, and the metal deposited on the surface is recovered metal. It is characterized by being dropped into a receiving tank and collected.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of one embodiment of the recovery apparatus according to the present invention, in which a packed tower 1, a stirrer 2 disposed in the packed tower 1, and a lower part of a bottom surface 3 of the packed tower 1 are shown. And a collection metal receiving tank 4 installed in the tank. Reference numeral 5 denotes a motor for rotating the stirrer 4.

The packed tower 1 is provided with an inlet 6 for introducing the solution A in which the metal to be recovered is dissolved into the packed tower 1 and an outlet 7 for discharging the solution A to the outside if necessary. Fill Group 8 The particle diameter of this particle group 8 is 2 to
It is about 10 mmφ.

The particle group 8 may be only a metal 9 which is lower than the metal to be recovered, but a particle group in which conductive particles 10 (electrically conductive particles) insoluble in the solution A are mixed with the base metal 9. 8 is preferable.

The reason for this is that by mixing these metal particles 9 and 10, a local battery is formed in which the base metal particles 9 form a negative electrode and the conductive particles 10 serve as a positive electrode, and the base metal particles 9 alone form a battery. This is because the negative potential is much lower than in the case (1), and the deposition rate of the metal to be recovered is accelerated.

In this case, in particular, the deposition of the recovered metal occurs on the surface of the conductive particles 10, so that the amount of metal deposited on the surface of the base metal particles 9 is reduced, and the stirring effect described later is further enhanced. Can be

Next, the solution A in which the metal to be recovered is dissolved is introduced into the packed tower 1 filled with the particle groups 8 from the inlet 6, and the stirrer 2 is rotated by the operation of the motor 5 to rotate the particle groups 8. Is brought into contact with the particle group 8 while stirring.

Thus, the metal to be recovered in the solution A precipitates on the surface of the particle group 8, and the metal precipitated on the surface is rubbed with the particle group 8 by the stirrer 2 and rubs with each other. The metal powder 11 is separated and falls into the collection metal receiving tank 4 and is collected as the metal powder 11.

In the apparatus of the present invention, the particle groups 8
May be applied with a DC voltage. In the figure, reference numeral 12 denotes a DC power supply, which is connected to an anode 13 disposed in the packed tower 1.
And the particle group 8 is shifted to the cathode, thereby suppressing unnecessary dissolution and consumption of the base metal particles 9.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited to these embodiments.

EXAMPLE 1 One liter of Al particles having a diameter of 3 to 5 mm was filled as a base metal, and a silver cyanide / plating diluent having a silver concentration of 100 ppm was applied per hour.
A 15 liter treatment was performed. FIG. 2 shows the recovery results obtained when the particles were agitated and when the particles were not agitated.

FIG. 2 shows that when stirring was performed, 93.0
% Recovery was obtained, but without stirring, the precipitated silver
Since the surface was covered, only a recovery of 82.0% was obtained. Therefore, without stirring, the surface was covered with silver, the recovery rate was extremely reduced, and the stirring effect was confirmed.

Example 2 One liter of a mixture of 3 to 5 mm Al particles and Fe particles in which the mixing ratio was changed. This mixture was packed in a packed tower, and a stirring test was conducted by passing 12.5 liters of a silver cyanide plating solution diluent having a silver concentration of 100 ppm per hour while stirring, and the results were shown in FIG.

FIG. 3 shows that the recovery rate is 93 when only Al particles are used.
%, The recovery in the case of a mixture was 98% or more, indicating that the effect of the mixture was obtained. Also,
The recovered metal was recovered as a powder.

Example 3 A mixture (1) was obtained by mixing 3 to 5 mm Al particles as a base metal and 3 to 5 mm Fe particles as an insoluble conductor at a volume ratio of 30:70. This was filled and stirred in the same manner as in Example 1, and a DC voltage of 13 V was applied between the mixture and the anode.
Silver cyanide plating diluent with silver concentration of 100ppm per hour
After passing through 15 l, silver was recovered. The amount of dissolved Al was measured when 1 g of silver was recovered when a DC voltage was applied and when no DC voltage was applied. The recovery was both 98% or more, and the recovered silver was recovered as a powder. The results are shown in Table 1.

[0025]

[Table 1]

From the results shown in Table 1, it can be seen that when recovering the same amount of silver, applying a DC voltage can suppress the amount of dissolved Al to 1 / 2.5 when no voltage is applied.

Example 4 In the same manner as in Example 2, 13 L of a silver cyanide plating solution diluent having silver concentrations of 50, 500 and 7000 ppm was passed per hour to obtain a recovery rate shown in Table 2.

[0028]

[Table 2]

Table 2 shows that a high recovery rate can be obtained from a low concentration to a high concentration liquid.

Example 5 3-5 mm Al particles and 3-5 mm stainless particles as an insoluble electric conductor were mixed at a volume ratio of 30:70 to obtain a mixture. One liter of the mixture was filled, stirred, and passed through an aqueous solution of copper sulfate having a copper ion concentration of 50 ppm while applying a DC voltage of 10 V to perform a copper recovery test. As a result, a recovery rate of 99.0% or more was obtained, and copper was recovered as copper powder.

[0031]

According to the above-mentioned present invention, since the particle group 8 which is the precipitation reaction field is the surface of the granular material, the area of the reaction field is very large, and the reaction field can be efficiently used even from a low concentration solution A for a short time. Is collected as metal powder.

Moreover, the particles 8 on which metal is deposited on the surface
Are rubbed against each other by stirring, the metal falls off the surface of the particle group 8 and is collected as the metal powder 11 without any trouble.

In addition, the surface of the particle group 8 is not covered with the metal, and the substitution reaction does not stop due to the fall-off of the deposited metal. Therefore, the reaction occurs continuously, and the continuous recovery is performed. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a specific example of a recovery device according to the present invention.

FIG. 2 is a graph showing a comparison between a silver recovery amount and a recovery ratio with and without stirring.

FIG. 3 is a graph showing a comparison between a mixing ratio with and without silver stirring and a silver recovery rate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filling machine 2 Stirrer 3 Bottom surface 4 Recovery metal receiving tank 6 Inlet 8 Particle group 9 Base metal particles 10 Conductive particles 11 Metal powder A solution

Claims (7)

[Claims] 1. A method in which a solution in which a metal to be recovered is dissolved is passed through and brought into contact with particles of a metal which is more noble than the metal, and the metal to be recovered is deposited on the surface of the particles and recovered. ,
In the solution, the particles are rubbed against each other to collect the metal to be recovered deposited on the surfaces of the particles from the surface and recover the particles, and to keep the surface of the particles constantly active. Metal recovery method. 2. The method for recovering metal in a solution according to claim 1, wherein the particles are rubbed against each other by stirring. 3. The method for recovering metal in a solution according to claim 1, wherein said particle group is obtained by mixing said base metal particle group with a conductive particle group insoluble in said solution. 4. The method for recovering a metal in a solution according to claim 1, wherein a DC voltage is applied to the particle group. 5. A packed tower, a stirrer disposed in the packed tower, and a collecting metal receiving tank installed below a bottom surface of the packed tower, wherein the packed tower is a solution in which a metal to be recovered is dissolved. At least the inlet of, the inside is filled with a group of particles of a metal that is more noble than the metal to be recovered, and in the group of particles, a solution in which the metal to be recovered introduced from the inlet is dissolved. Contacting with a stirrer while stirring to precipitate the metal to be recovered in the solution on the surface of the particle group, dropping the metal deposited on the surface into a recovery metal receiving tank, and recovering the solution. Metal recovery equipment. 6. The apparatus for recovering metal in a solution according to claim 5, wherein the group of particles according to claim 5 is obtained by mixing the group of particles of the base metal with the group of conductive particles insoluble in the solution. 7. The apparatus for recovering metal in a solution according to claim 5, wherein a DC voltage is applied to the particle group according to claim 5 or 6.