JP6366039B2 - Precious metal recovery method - Google Patents

Description

  The present invention relates to a method for recovering a noble metal, and more particularly to a method for recovering silver by dissolving and peeling silver or a silver-based alloy from a surface of a substrate coated with silver or a silver-based alloy.

  As an electronic material, it is widely used to apply or form a film of a silver-based alloy such as silver brazing on an iron-based alloy base material to form a silver brazing-coated iron alloy. For example, iron / nickel / cobalt alloy sheet material that has a thermal expansion coefficient close to that of ceramic or glass, with silver brazing applied to both surfaces, is suitable for joining metal and ceramic or glass, and the shape of the joint surface It is used for hermetically sealing a piezoelectric vibrator, a piezoelectric oscillator, etc.

  When such an iron alloy coated with silver solder is used as an electronic material, a large amount of processing waste such as punching waste is generated. For example, when a silver alloy silver solder is applied on an expensive iron-based alloy base material such as iron, nickel, and cobalt alloy, the base material itself and the applied silver are also recovered and recycled. It is hoped that.

  In particular, in an iron-based alloy base material, since an expensive metal such as nickel or cobalt is used as an alloy component as described above, it is preferable that only a portion of a silver-based alloy such as a silver solder coated without being completely dissolved is coated. It is desired to separate and recover.

  Separation by a mechanical method such as grinding is incomplete, and there is a concern that new contamination may occur, which is not preferable.

From the solid body material such as an electronic component scrap noble metal is deposited on a substrate surface, dissolution release treatment by a wet process using an acid or alkali solution to recover dissolved peeling a noble metal is generally known Yes. However, in order to dissolve peeling a noble metal deposited on a solid body material surface is contacted with acid or alkali solution, because the overlap of the solid body material together only was immersed in the liquid occurs, and dissolved stripping solution for overlapping part The contact of the metal is reduced and it is difficult to completely dissolve and peel the noble metal.

For this reason, processing is generally performed using a barrel device as disclosed in JP-A-2-159324 shown as Patent Document 1 or a rotating device such as a mixer. However, the processing by the tilt-type mixer rotating device, because it is always fresh surface easily overlap solid body material with each other is not exposed, but also affected by the processing time, there is a problem that dressing can not be completely dissolved.

JP-A-2-159324

The dissolution release treating liquid with a solid body material is rotated and poured into a mixer drum, in the method rotates moving the solid object batch inputted to recover the precious metal, the larger the inclination angle with respect to the horizontal direction of the mixer drum, i.e. drum decreases the moving amount of the lower portion of the solid-body material by the weight of the solid body material present in the upper extent standing near vertically, the noble metal tends to remain in the residue. Therefore, efficient processing can be device and method to facilitate contact of the dissolution liquid and solid body material is desired.

The present invention has been made in view of the above problems, it is an object of the method of the solid-body material was placed by the rotational movement to recover the precious metal, stirring of the raw materials present in the drum lower part of the mixer It is an object of the present invention to provide a method for recovering a noble metal with improved solubility by promoting the above.

To solve the above problems, a method of recovering precious metals of the present invention, lysates introduced by rotationally driving the tilting mixer drum noble metal on the substrate to dissolve the noble metal and the solid body material coated , upon recovering the noble metal poured mixture stirred to, lay as the drum inclination angle of the mixer is 20 ° to 30 ° of angular degrees with respect to the horizontal direction, the solid body material present in the drum lower While facilitating stirring, a liquid feeding pipe for sending the processing liquid to the drum, a draining pipe for discharging the processing liquid from the drum, and discharging the processing liquid from the drum via the draining pipe A processing liquid circulation means comprising a pump for sending the processing liquid to the drum via a liquid feeding pipe, and the discharge port at the tip of the drum side of the liquid feeding pipe serves as a liquid for the processing liquid in the drum Above the surface So that the suction port at the tip of the drain side of the drainage pipe is positioned at a level substantially equal to the liquid level of the processing liquid in the drum, and the melt discharged into the drum via the pump When the liquid level of the stripping treatment liquid becomes equal to or higher than the height of the suction port at the tip of the drain side of the drain pipe, the amount of the liquid becomes equal to or higher than the height of the suction port at the end of the drain side of the drain pipe. So that the solid raw material is always brought into contact with the processing liquid while keeping the liquid level of the processing liquid in the drum at a substantially constant height. Dissolve the processing liquid sucked up from the drum via the drain pipe by the pump by shower spraying from the upper part of the drum to the raw material exposed from the liquid level of the processing liquid via the liquid feeding pipe. I tried to improve the performance It is characterized in.

  In the precious metal recovery method of the present invention, a tank for storing the processing liquid is provided, the processing liquid in the drain pipe is sent to the tank, and the processing liquid stored in the tank is sent by the liquid feeding pipe. It is preferable to be sent to the drum.

In the method of recovering precious metals present invention, the solid body material noble metal on the base material is coated with a solid body material silver-based alloy of silver solder or the like is coated on the alloy substrate of ferrous The solution for dissolving the noble metal is preferably a nitric acid solution or a cyan solution.

  In the precious metal recovery method of the present invention, the certain angle is preferably 30 °.

By an angle with respect to the horizontal direction of the mixer drum as small as 20 ° to 30 ° to a gentle inclination angle, the charged solid-body material, in particular agitation of solid body material of the drum lower part is promoted, the processed It becomes possible to keep the precious metal residue in the base material below a certain value (for example, the silver residue is 50 ppm) or less, and at all times, the solid material is brought into contact with the treatment liquid via a drain pipe. Then, the treatment liquid drawn from the drum is sprayed from the upper part of the drum to the raw material exposed from the liquid surface of the treatment liquid via a liquid feed pipe, so that the solubility of the noble metal from the base material is improved .

It is explanatory drawing of the noble metal melt | dissolution peeling apparatus provided with the tiltable mixer and tank for process liquid storage used by this invention. It is explanatory drawing of the collection | recovery method of the noble metal of this invention using the melt | dissolution peeling apparatus of the noble metal shown in FIG. It is a graph which shows the relationship between the inclination-angle of a drum, and the residual amount of silver.

Method for recovering precious metals present invention for example, introducing silver based alloy solid body material coated with a nitric acid solution or cyan-based solution of silver solder or the like on the alloy substrate of an iron-based to tilting mixer drum rotation When the mixture is stirred to collect silver by driving, the drum inclination angle of the mixer is set to an angle of 20 ° to 30 ° with respect to the horizontal direction. By doing in this way, stirring of the raw material which exists in the drum lower part is accelerated | stimulated, and a solubility improves.

Considering the holdings and agitation of the mixer of the processing liquid in the solid body material and the drum to be introduced, the optimum angle to the horizontal mixer drum is considered to be 30 ° to 45 °. Drum can much amount of solid body material stockpile is increased can put the treatment liquid drum as standing nearly vertically. However, when processing a mixture of solid bodies material of different particle size and shape, small material shape is has moved to the drum lower part of the mixer, because it is pressed against the large material shaped to present the top, without being well stirred It was confirmed that the film was in close contact and dissolution and peeling were insufficient. Therefore, in the present invention, tilt angle for example 20 ° ~ 30 ° with respect to the horizontal direction of the mixer drum, Ri is gently Na pressing due to the large material shaped to present in the drum top, even raw materials present in the drum lower part In addition, the fluidity in the stirring state, that is, in the liquid is promoted.

In addition, a liquid feeding pipe for sending the processing liquid to the drum, a draining pipe for discharging the processing liquid from the drum, and a processing liquid is discharged from the drum via the draining pipe, and the drum passes through the liquid feeding pipe. A processing liquid circulation means comprising a pump for sending the processing liquid to the drum is provided, the discharge port at the tip of the drum side of the liquid feeding pipe is positioned above the liquid level of the processing liquid in the drum, and the drum side of the drainage pipe The suction port at the front end is positioned at a level substantially equal to the liquid level of the processing liquid in the drum, and the liquid level of the dissolution peeling processing liquid discharged into the drum via the pump is on the drum side of the drainage pipe. When the height of the suction port at the tip becomes equal to or higher than the height of the suction port at the tip of the drum side of the drainage pipe, the amount of the dissolution and removal treatment liquid is sucked up from the suction port at the tip of the drum, While maintaining the liquid level of the treatment liquid at a nearly constant height Always as contacting the solid material in the processing solution, via a liquid transfer pipe to material that is exposed from the liquid surface of the treatment liquid from the drum upper treatment liquid sucked up from the drum via the drainage pipe with a pump And spray it in the shower.

During situations where solid body material is exposed from the liquid surface, and a shower spray dissolved stripping solution from the drum top, always contact the treatment liquid to the solid material by contacting the solid body material and the treatment liquid accelerator As a result, the dissolution and peeling time can be shortened. For example, when recovering silver, hydrochloric acid can be added to the dissolved processing solution to selectively recover only silver as silver chloride.

Next, prior to the description of the noble metal recovery method of the present invention, an example of a noble metal dissolution and peeling apparatus used in the present invention will be described with reference to FIG.
The precious metal dissolution and peeling apparatus shown in FIG. 1 includes a tiltable mixer 1, a treatment liquid storage tank 2, and a treatment liquid circulation means 3.

  The tiltable mixer 1 has basically the same structure as that of a tilting barrel type mixer used for mixing concrete, and includes a base 11, a drum 12, and a drive device 13 for the drum 12. The drum 12 is formed so that the diameters of the lower and upper portions of the drum are gradually reduced, the upper end is open, and a stirring protrusion is provided inside the drum. The driving device 13 includes a motor 131 provided at a lower end portion of the drum 12 for rotating the drum 12 with the vertical center of the drum 12 as a rotation axis, and a drum rotating device 132 for tilting the drum 12. Has been. The drum 12 can be rotated at an arbitrary angle by the drum rotating device 132. In the present application, the angle A formed by the rotation axis of the drum 12 with respect to the horizontal direction is defined as the inclination angle of the drum 12.

The processing liquid storage tank 2 is not limited in material and shape as long as it can store the processing liquid. The capacity, if the effective capacity to introduce processing liquid mixer drum 12 has a maximum C [l], to allow recovery of precious metals mixed by stirring drum 12 single processing amount Beyond solid body material, to the entered solid body material and at least stored is the capacity of the treatment liquid of the amount exceeding the C [l].

  The processing liquid circulation means 3 includes a liquid feeding pipe 31 provided for feeding liquid from the tank 2 to the drum 12, a drainage pipe 32 provided for draining liquid from the drum 12 to the tank 2, and a liquid feeding pipe 31. The pump 33 is provided to circulate the processing liquid between the drum 12 and the tank 2 by the drain pipe 32.

  As the pump 33, for example, the liquid feed pipe 31 is provided with a liquid feed aired pump 331, and the liquid discharge pipe 32 is provided with a liquid discharge aired pump 332. The aired pump is preferable because it does not cause trouble even in idling operation and is excellent in chemical resistance. However, other pump types may be used depending on the mounting position of the liquid feeding pipe 31 and the drainage pipe 32. Further, when the tank 2 is not provided and the processing liquid extracted from the drum is sprayed from the liquid surface of the drum as it is, one pump 33 may be provided.

Next, the noble metal recovery method of the present invention using the above-described noble metal dissolution and peeling apparatus will be described with reference to FIG .

Each put the desired amount of treatment liquid drum 12 and the tank 2 of the tilting mixer 1 solid body raw material charged into the drum 12. Then, aged as a drum inclination angle by the drum rotation device 132 of the drum 12 at an angle of 20 ° to 30 ° to the horizontal direction, the drum 12 driving a motor 131 is rotated the desired time for stirring and mixing. In this way, the stirring of the solid material existing under the drum 12 is also promoted, so that the entire solid material is uniformly dissolved. In addition to the stirring and mixing by the rotation of the drum 12, the processing liquid is circulated between the drum 12 and the tank 2 by the liquid feeding aird pump 331 and the liquid discharging aired pump 332, and the drum side end of the liquid feeding pipe 31 is circulated. shower sprayed treatment liquid from the discharge port, so that blown to the solid body material that protrudes from the liquid surface W of the treatment liquid.

In this case, the discharge port at the tip of the drum 12 side of the liquid feeding pipe 31 is positioned above the liquid surface W of the processing liquid of the drum 12, and the suction port at the tip of the drum 12 side of the drainage pipe 32 is the processing liquid of the drum 12. It is made to be located at the height which is almost equal to the liquid level W. By doing so, the liquid level W can be maintained at a substantially constant height in the drum 12. By the drained aired pump 332, the level W of the dissolution and peeling treatment liquid in the drum quickly became higher than the suction port 321 when the level became higher than the suction port at the tip of the drain side of the drain pipe 32. Only the dissolved and stripped treatment liquid is sucked up from the suction port 321 and discharged into the tank 2. The contact of the treatment liquid to the solid material is promoted by the treatment liquid ejected from the liquid feed pipe 31 by the fluid supply air de pump 331 befall as shower solid body material that protrudes from the liquid surface W As a result, dissolution and peeling are promoted.

Example 1
Lysates 200L effective capacity for silver grade 17% of the solid body material 15kg silver grade 17% of solid body material 15kg were charged into a drum mixer, and the inclination angle of the drum to 30 °, 2 hours When the residual amount of silver in the base material as a residue after the stirring treatment was examined, it was about 50 ppm.

Next, in lysates 200L of effective capacity for the same silver grade 17% of the solid body material 15 kg, 15 ° angle of inclination of the drum, 25 °, 35 °, it is set to 45 °, stirred for respectively 2 hours The residual amount of silver in the base material, which was a residue after the treatment, was confirmed. The result is shown in FIG.
When the drum tilt angle of the mixer was 15 ° and 25 °, the residual amount of silver was about 10 ppm, and the result was 50 ppm or less, but when it exceeded 35 °, the residual amount was 50 ppm or more. Residual amount of silver after the treatment has to desirable to 50ppm or less. However, the inclination angle that the too small and too reduces the effective capacity of the drum, Ru only Ri a small amount of solid body material that can be processed at one time. Therefore, the inclination angle of the drum is required 20 ° to 30 °, preferably switching applied is 25 ° ~ 30 °.

(Example 2)
As in Example 1, a solution of 200L of effective capacity for silver grade 17% of the solid body material 15kg silver grade 17% of solid body material 15kg were charged into a drum mixer, a tilt angle of the drum 20 ° The test which added the shower spray mentioned above was implemented.
In the situation without shower spraying, it took 2 hours to reduce the residual amount of silver to 10 ppm or less, but in 1 hour 45 minutes it was reduced to 10 ppm or less, and shower spraying was effective in shortening the dissolution time. It was confirmed that there is.

  In addition, although each said Example demonstrated the case where a noble metal was silver, the noble metal which can apply the collection | recovery method of this invention is not limited to silver, The gold | metal | money, platinum, palladium etc. which other normal collection | recovery is performed It can be applied to various kinds of precious metals.

DESCRIPTION OF SYMBOLS 1 Inclinable mixer 11 Base 12 Drum 13 Drive apparatus 131 Motor 132 Rotating apparatus 2 Tank 3 Circulation means 31 Liquid feed pipe 32 Liquid drain pipe 33 Pump 331 Liquid feed air pump 332 Waste liquid air pump A Inclination angle W liquid level

Claims (3)

And a solution of noble metal on the substrate to dissolve the noble metal and the solid body material coated introduced by rotationally driving the tilting mixer drum, upon recovering the noble metal poured mixture stirred to said mixer together with the drum inclination angle laid so that the 20 ° to 30 ° of angular degrees with respect to the horizontal direction, to facilitate the stirring of the solid body material present in the drum bottom of,
A liquid feeding pipe for sending the processing liquid to the drum, a draining pipe for discharging the processing liquid from the drum, a processing liquid being discharged from the drum via the draining pipe, and via the liquid feeding pipe And a processing liquid circulating means comprising a pump for feeding the processing liquid to the drum, and the discharge port at the tip of the drum side of the liquid feeding pipe is positioned above the liquid level of the processing liquid in the drum. The suction port at the tip of the drain side of the drain pipe is positioned at a height substantially equal to the liquid level of the processing liquid in the drum, and the dissolution peeling process discharged into the drum via the pump When the level of the liquid becomes equal to or higher than the height of the suction port at the front end of the drum side of the drainage pipe, dissolution corresponding to the height of the suction port at the front end of the drain side of the drainage pipe Remove the stripping solution from the suction port at the tip of the drum. In order to maintain the liquid level of the processing liquid in the drum at a substantially constant height, the drum is in contact with the processing liquid at all times by the pump via the drain pipe. A precious metal characterized in that the solubility is improved by spraying the treatment liquid sucked from inside the raw material exposed from the liquid surface of the treatment liquid from the upper part of the drum via the liquid feeding pipe. Recovery method. A tank for storing a processing liquid is provided, the processing liquid in the drain pipe is sent to the tank, and the processing liquid stored in the tank is sent to the drum through the liquid feeding pipe. The method for recovering a noble metal according to 1 . The group solid body material noble metal is coated on material are solid body material silver-based alloy of silver solder or the like is coated on the alloy base member of iron-based, solution is nitric acid to dissolve the noble metal method for recovering precious metals according to claim 1 or 2, wherein the solution or a cyanide solution.

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