TWI409365B - Method for recovering noble metal ions from plating - Google Patents

Abstract

[Problem] To provide a method that can: efficiently recover precious-metal ions from precious-metal-ion-containing plating wastewater discharged from a plating recovery tank and a plating cleaning tank; and minimize performance problems in objects being plated. [Solution] The present invention is a method for recovering precious-metal ions from plating wastewater. Said method keeps the concentration of precious-metal ions in a solution in a plating recovery tank high, within a certain range, by setting the wastewater discharge volume per discharge from the plating recovery tank to an amount, from 10% to 50% of the capacity of said plating recovery tank, such that the object being plated stays immersed in said plating recovery tank. Said method also keeps the concentration of precious-metal ions in a solution in a plating cleaning tank low, within a certain range.

Description

Method for recovering precious metal ions from plated drainage

The present invention relates to a method for recovering precious metal ions from a plating drainage, and particularly relates to high-efficiency recovery of precious metal ions in plating drainage from a plating recovery tank and a plating cleaning tank, and suppressing performance of a plating material to be treated Poor method of recovering precious metal ions from plating drainage.

The precious metal is industrially very useful because it is excellent in physical properties, reliability, and aesthetics, and is used as a plating material in a wide range of fields including electronic components such as electronic components and printed wiring boards. On the other hand, precious metals are scarcely present and are very expensive materials. Therefore, it is required to recover and reuse the precious metal contained in the plating drainage as much as possible.

Generally, the plating drainage system is divided into drainage water from a plating tank, a plating recovery tank, and a plating washing tank. Since the plating recovery tank functions as a primary cleaning tank after the plating treatment of the plating tank, the drainage water from the plating recovery tank contains a noble metal ion having a lower concentration than the drainage water of the plating tank. Further, since the plating washing tank functions as a secondary or tertiary washing tank, the drain water from the plating washing tank contains a noble metal ion having a lower concentration than the drain of the plating collecting tank. As such, the concentration of precious metal ions in the plating drainage discharged from each tank is different.

In addition, it is required to wash out precious metal ions or salt components excessively adhered to the plating target in the plating recovery tank and the plating washing tank, and to suppress mold or bacteria caused by organic substances of the components of the plating solution. The occurrence and management of the plating tank.

As a method of recovering precious metal ions from the plating drainage, an electrolytic recovery method, a resin recovery method, and an activated carbon adsorption recovery method are generally known. The electrolytic recovery method is excellent for recovering precious metal ions from plating drainage having a high concentration of noble metal ions. However, if the plating is drained at a low concentration, the current density does not rise even if the electrolytic cell is circulated, and the noble metal ions are not increased. The recycling efficiency is worse. On the other hand, the resin recovery method and the activated carbon adsorption recovery method are excellent in recovering precious metal ions from plating drainage having a low concentration of noble metal ions. However, if a high-concentration plating drainage is passed, the precious metal ions cannot be sufficiently recovered. . Therefore, it is necessary to manage the concentration of noble metal ions when draining from the plating bath.

As a method for efficiently recovering a noble metal from a plurality of kinds of waste liquids containing precious metals in various concentrations, for example, it is known that a low-concentration waste liquid containing a noble metal at a low concentration is passed through a chelate-type ion exchange resin, and a noble metal is adsorbed to the chelate. A method of extracting a noble metal adsorbed by a high-concentration waste liquid containing a noble metal at a high concentration in a electrolytic cell, and depositing a precious metal on the electrode to recover the deposited precious metal (Patent Document 1) .

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2001-279343

Conventionally, as a method of partially draining from the plating recovery tank, a method of periodically overflowing or a time management method of automatically draining by a timer and periodically draining the water, or a method of manually draining the water manually by the operator is employed. In this manner, the precious metal ion concentration of the contained liquid in the plating recovery tank is periodically reduced by periodically discharging a predetermined amount of the liquid in the plating recovery tank and water injection.

However, the concentration of the noble metal ions of the contained liquid in the plating recovery tank does not always increase at a constant rate, and may rise sharply depending on the situation. Further, according to the production amount of the plated material to be treated, the concentration of the noble metal ions in the solution liquid in the plating recovery tank varies in various ways. Therefore, when plating drainage containing a relatively low concentration of noble metal ions, a sufficient current density cannot be obtained, and the efficiency of recovering precious metal ions by the electrolytic recovery method is deteriorated. On the other hand, in the case of plating drainage containing a relatively high concentration of noble metal ions, the cycle time which is automatically set cannot be handled, which is a cause of lowering the recovery efficiency of noble metal ions.

When the concentration of the noble metal ions of the liquid in the plating tank is excessively increased, the concentration of precious metal ions contained in the plating drainage from the plating tank of the treatment tank in the subsequent step is increased by the resin recovery method. The activated carbon adsorption recovery method recovers the problem that the noble metal ion system cannot be sufficiently changed.

An object of the present invention is to provide a method for efficiently recovering precious metal ions from a plating drainage water containing precious metal ions discharged from a plating recovery tank and a plating cleaning tank, and suppressing poor performance of a plating material to be treated .

In order to solve the above problems, the inventors of the present invention have conducted intensive studies and found that the precious metal ion concentration of the liquid in the plating recovery tank and the plating cleaning tank is maintained within a specified range, and based on this knowledge, the present invention is finally completed. invention. That is, the present invention is a method for recovering precious metal ions from a plating drainage by making the amount of water discharged from the plating recovery tank into a range of 10 to 50% of the amount of water in the plating recovery tank, and plating. In the coating tank, the amount of the impregnation of the material to be treated is ensured, and the concentration of the noble metal ions of the liquid in the plating recovery tank is maintained at a high concentration in a high concentration, and the plating chamber is accommodated in the cleaning tank. The precious metal ion concentration of the liquid is maintained at a low concentration in a certain range.

In the present invention, the plating drainage from the plating recovery tank can be maintained at a high concentration in the concentration of the noble metal ions, and the noble metal ions can be recovered by the electrolytic recovery method and the resin recovery method or the activated carbon adsorption recovery method. The concentration of the noble metal ions is maintained at a low concentration in a plating bath from the plating bath at a low concentration, and the noble metal ions are recovered by a resin recovery method or an activated carbon adsorption recovery method.

According to the present invention, it is possible to efficiently recover precious metal ions from the plating drainage water containing precious metal ions discharged from the plating recovery tank and the plating cleaning tank without stopping the plating treatment of the plated workpiece. The performance of the plating object to be treated is suppressed to be poor.

[Formation of the Invention]

The present invention is applied to a general plating treatment, that is, a treatment comprising the steps of immersing a workpiece in a plating bath containing a plating solution to perform plating, in a liquid in a plating recovery tank. a step of immersing the object to be treated, first washing the object to be treated, immersing the object to be treated in the solution liquid in the plating tank, and finally washing the object to be treated; and plating drainage from the plating recovery tank And recovering precious metal ions by electrolytic recovery method, resin recovery method or activated carbon adsorption recovery method. On the other hand, for the plating drainage from the plating cleaning tank, the precious metal is recovered by the resin recovery method or the activated carbon adsorption recovery method. ion.

The object to be processed is a product which is continuously plated by a pair of rolls, such as an electronic component or a printed wiring board, and is subjected to repeated immersion and lifting steps in a plating bath or the like, and the processed product is plated in batches. Further, the plating solution in the plating recovery tank and the plating washing tank is usually ion-exchanged water treated with an ion exchange resin, but is activated after recovering precious metal ions from the liquid containing the plating bath. Pure water treated with carbon treatment and reverse osmosis membrane is also suitable.

In the present invention, the amount of water discharged from the plating recovery tank is in the range of 10 to 50% of the total amount of water in the plating recovery tank, and in the plating recovery tank, the plating material is ensured. The concentration of the noble metal ions in the receiving liquid in the plating recovery tank is maintained at a high concentration in a high concentration, and the concentration of the noble metal ions in the receiving liquid in the plating cleaning tank is maintained at a low concentration at a constant concentration. range. Further, the plating drainage from the plating recovery tank can be maintained at a high concentration for the concentration of the noble metal ions, and the noble metal ions can be recovered by the electrolytic recovery method and the resin recovery method or the activated carbon adsorption recovery method for the noble metal ions. The plating drainage from the plating washing tank is maintained at a low concentration at a low concentration, and the noble metal ions are recovered by a resin recovery method or an activated carbon adsorption recovery method.

The amount of water discharged from the plating recovery tank is preferably in the range of 10 to 50% of the total amount of water in the plating recovery tank, and in the plating recovery tank, it is preferable to ensure the amount of impregnation of the plating material to be treated. . When the amount of water per drain exceeds 50% of the amount of water in the plating recovery tank, the water temperature in the plating recovery tank greatly changes due to water injection, and excess precious metal ions or salt components adhering to the material to be treated are recovered. The efficiency is lowered, and molds, bacteria, and the like are easily propagated, and adhesion to the plated material is caused, resulting in poor performance or a decrease in yield.

On the other hand, if the amount of displacement per time is less than 10% of the full amount of water, the management of the precious metal ion concentration and the drainage and water injection operation of the plating recovery tank become complicated. In addition, management troubles occur due to troublesome work, and the efficiency of recovering excess precious metal ions or salt components adhering to the material to be plated is reduced, which not only contaminates the material to be treated, but also reduces the recovery efficiency of precious metal ions. . In addition, the reason why the amount of water discharged per time is the amount of immersion for ensuring the plating target material is to prevent the plating process from being stopped.

Further, the water temperature of the liquid contained in the plating recovery tank is preferably 35 ° C or higher, more preferably 40 ° C or higher. The plating recovery tank does not necessarily require a positive temperature adjustment, but it is preferred that the water temperature is not excessively lowered. In particular, when the water temperature is lower than 35° C., the elution efficiency of excess precious metal ions or salt components adhering to the material to be treated is deteriorated, and the growth of molds, bacteria, and the like is promoted. Residual precious metal ions or salt components or mold or bacteria adhesion, resulting in poor performance and reduced yield.

Generally, the plating treatment is applied to the plating bath at a heating state of about 60 to 90 °C. Therefore, the plated material to be treated which has been heated and the plating liquid adhering to the material to be plated are moved in the plating recovery tank, which causes the water temperature in the plating recovery tank to rise. Another reason for the increase in the temperature of the water in the plating recovery tank is that the plating bath and the plating recovery tank are continuously provided, and the radiant heat from the plating tank is caused.

However, an increase in the temperature of the water does not necessarily result in poor performance or a decrease in yield of the plated material to be treated in the plating recovery tank. As a matter of course, as described above, the water temperature of the storage liquid in the plating recovery tank is preferably 35° C. or higher, more preferably 40° C. or higher, and particularly, excess precious metal ions or salt components adhering to the plating target material. From the standpoint of good washing out efficiency and inhibition of the growth of mold or bacteria, it is preferred that the water temperature is high.

In general, when the amount of treatment of the plated workpiece is small, in the conventional time management method, the overflow method, and the full amount replacement method, drainage and water injection are excessively performed, which causes a decrease in water temperature.

Therefore, in the present invention, as will be described later, it is important to provide an electrode in the plating recovery tank, and estimate the amount of the deposited metal material by the current value and the concentration of the noble metal ion via the calibration curve to estimate the amount of the processed material to be processed. The amount of displacement per one time of the plating recovery tank is in the range of 10 to 50% of the total amount of water in the plating recovery tank. For example, when the water temperature of the plating recovery tank is 50° C., when the water temperature of the plating recovery tank is 50° C., the water temperature is reduced by 10° C., and the water temperature is reduced by 10° C., even if the treated material is treated. When the amount is relatively small, the water temperature is not managed below 35 °C.

In the present invention, the noble metal ion concentration of the contained liquid in the plating recovery tank is maintained at a high concentration in a predetermined range. The drainage which is maintained at a high concentration in a certain range is suitable for the electrolytic recovery method, the resin recovery method or the activated carbon adsorption recovery method.

Here, the fact that the concentration is maintained at a high concentration in a predetermined range means that the concentration of the noble metal ions of the contained liquid in the plating bath is maintained at a low concentration and maintained at a high concentration.

Further, in the design of the apparatus for recovering precious metal ions, the number of the electrolytic recovery devices, the amount of the resin and the amount of the activated carbon, and the like are appropriately selected in accordance with the concentration of the noble metal ions or the amount of the treatment per unit time. Further, according to the noble metal ion recovery method of the present invention, even if the plating drainage from the plurality of plating recovery tanks arranged in parallel is contained, as long as the same noble metal ions are contained, the plating drainage can be collected in one route. Electrolytic recovery.

In the embodiment of the present invention, when the noble metal ion is at a high concentration, the electrolytic recovery method, the resin recovery method, or the activated carbon adsorption recovery method are suitably selected, and on the other hand, when the concentration is low, the resin recovery method or activated carbon is appropriately selected. Adsorption recovery method.

In order to electrolyze the precious metal ions of the contained liquid in the recovery tank with high efficiency, it is preferable to maintain the concentration of the noble metal ions in a certain range when the recovery apparatus is put into the recovery apparatus. In the general electrolytic recovery method, a recovery device such as the number of installations of the electrolytic recovery device is designed in accordance with the concentration of precious metal ions in the drainage of the plating device or the amount of treatment per unit time of the drainage. The storage liquid discharged from the plating recovery tank is once stored, and a certain amount of treatment is moved from the storage tank to the electrolytic recovery tank, and the storage liquid is circulated in the electrolytic recovery tank and the electrolytic recovery unit, and the precious metal is electrolytically recovered. ion. The electrolysis recovery is set by the cycle time, and the cycle time is appropriately adjusted for the fluctuation of the noble metal ion concentration. Therefore, the so-called range is to maintain the concentration of the processing performance of the recovery equipment suitable for designing precious metal ions. If it exceeds a certain range, it will exceed the recovery capacity of the resin or activated carbon adsorption recovery after electrolysis recovery, and the recovery efficiency. reduce. On the other hand, if it is less than a certain range, in the electrolytic recovery, the recovery efficiency of a low concentration is low, and the collection efficiency per unit time falls.

According to the above, when the concentration of the noble metal ions of the contained liquid is maintained at a high concentration in a certain range, the recovery efficiency of the recovery equipment can be utilized to the utmost, and as a result, a high yield can be achieved.

In addition, in the liquid to be contained in the plating recovery tank, the current density may not be sufficiently increased depending on the type of the plating liquid, and an electrolyte such as caustic soda may be arbitrarily added in order to increase the current density.

For example, when the noble metal ions of the storage liquid in the plating recovery tank defined by the present invention are maintained at a high concentration in a certain range, it is preferably maintained in the range of 10 to 200 mg/L. When the concentration of the noble metal ions in the storage liquid in the plating recovery tank exceeds 200 mg/L, the recovery of the noble metal ions is insufficient even if the electrolytic recovery method, the resin recovery method, or the activated carbon adsorption recovery method are used in combination, and the excess noble metal ions are excessive. When it flows out to the plating washing tank, the possibility that the precious metal ion concentration of the plating washing tank exceeds 10 mg/L becomes high, and the recovery efficiency of the noble metal ion contained in the plating drainage from the plating washing tank is reduced.

On the other hand, if the concentration of the noble metal ions of the contained liquid in the plating recovery tank is less than 10 mg/L, the combination of the electrolytic recovery method and the resin recovery method or the activated carbon adsorption recovery method becomes an excessive design and becomes economically inefficient. . Moreover, the management of the concentration of the noble metal ions contained in the contained liquid in the plating recovery tank is less than 10 mg/L, and there is almost no embodiment, which is not realistic.

In the present invention, the precious metal concentration of the contained liquid in the plating cleaning tank is maintained by the plating recovery tank to the plating by maintaining the concentration of the noble metal ions in a constant concentration range in the plating recovery tank. The noble metal ions of the tank are maintained at a low concentration in a certain range. Further, the contained liquid in the plating recovery tank treated by the electrolytic recovery method is similarly maintained at a low concentration in a predetermined range. Since either of them can be maintained at a low concentration in a certain range, the filling amount of the resin and the activated carbon can be appropriately selected in accordance with the concentration of the noble metal ions and the amount of treatment per unit time.

For example, when the precious metal concentration of the contained liquid in the plating bath defined by the present invention is maintained at a low concentration in a predetermined range, it is preferably maintained at 10 mg/L or less. In this case, if it exceeds 10 mg/L, recovery of noble metal ions by the resin recovery method or the activated carbon adsorption recovery method may become insufficient.

As described above, since the concentration of the noble metal ions in the plating solution in the plating recovery tank is at most 200 mg/L, the maximum concentration of excess precious metal ions adhering to the plated material to be processed from the plating recovery tank is 200 mg/L. For example, if the above-mentioned adhering liquid is diluted to 25 to 50 times by pure water in the plating washing tank, the precious metal ion concentration at the time of 25-fold dilution is 8 mg/L, and 4 mg/L at the time of 50-fold dilution is maintained. Below 10mg/L.

In the present invention, when precious metal ions are recovered from the plating drainage of the plating recovery tank, they are carried out by an electrolytic recovery method, a resin recovery method or an activated carbon adsorption recovery method. Not only the electrolytic recovery method alone, but also in combination with the resin recovery method or the activated carbon adsorption recovery method, the recovery efficiency of noble metal ions can be remarkably improved.

The electrolytic recovery method is a method in which a plating drainage is introduced into an electrolytic cell, and precious metal ions are deposited on the electrode by electrolysis. As the anode to be used, an electrode made of a Pt-plated Ti material, an Ir sintered Ti material, or a fat-grained iron material can be exemplified, and as the cathode, an electrode made of a Ti material, a SUS material, or a fat iron material can be exemplified. In the present invention, as the condition for recovering the noble metal by high electrolysis efficiency in the plating drainage from the plating recovery tank, the type or current density of the electrode is appropriately set in accordance with the type of the plating solution and the noble metal ion species. For example, in the drainage of the cyanide plating solution, since the cyanide ions dissolve Pt, the Ti sintered electrode electrode is used. Further, in the drainage of the platinum group plating solution containing Pt or Pd or the like, since the precipitated platinum group is peeled off by hydrogen generated by hydrolysis of water, it is used at a low current density. In addition, the method of removing and recovering the precious metal deposited on the cathode is not particularly limited. However, when the precipitated noble metal is removed and recovered by aqua regia or the like, it is preferable to use a Ti material as the cathode.

The resin recovery method is a method in which a plating drainage is passed through a resin to collect precious metal ions, and the resin is burned to recover a precious metal. Examples of the resin used in the resin recovery method include a cation exchange resin, an anion exchange resin, a chelating resin, and a synthetic adsorption material, and it is preferred to recover precious metal ions with high efficiency. Specifically, an anion exchange resin such as a strongly basic ion exchange resin having a quaternary ammonium base (trimethylammonium base, dimethylethanolammonium base, etc.) or a weakly basic one having a primary, secondary or tertiary amine group An ion exchange resin or the like; a cation exchange resin such as a strongly acidic ion exchange resin having a sulfonic acid group, a super strong acidic ion exchange resin having a fluorinated alkylsulfonic acid group, and a weak carboxyl group, a phosphonic acid group, and a phosphinic acid group. An acidic ion exchange resin or the like; a chelate resin such as a mercaptoacetic acid type chelate resin or a polyamine type chelate resin is suitable.

The activated carbon adsorption recovery method used in combination with the electrolytic recovery method is a method of recovering noble metal ions by using activated carbon to trap precious metal ions, burning and activating the activated carbon, and recovering precious metal ions from the obtained ash. When the noble metal ions are trapped using activated carbon, for example, the plating water is impregnated with activated carbon, and the plating drainage is carried out through the activated carbon filled in the column.

When precious metal ions are recovered from the plating drainage of the plating washing tank, the resin recovery method or the carbon adsorption recovery method is used. The resin recovery method or the activated carbon adsorption recovery method is as described above.

When the amount of water discharged from the plating recovery tank is in the range of 10 to 50% of the total amount of water in the plating recovery tank, it is preferable that the drainage and water injection in the plating recovery tank are performed by a part of the drainage and a part of the water injection. In general, in order to perform a large amount of plating treatment in the industry, it is required to continuously treat the material to be processed in the plating recovery tank so as not to hinder the production of the material to be plated. However, if the entire amount of drainage is performed once, the material to be treated is plated. Since the plating treatment is stopped, the lead time is prolonged, and the productivity is lowered. In addition, when a full amount of water is injected and a full amount of water is injected, the water temperature of the plating recovery tank is largely changed, so that the recovery efficiency of precious metal ions is lowered.

The method of setting the amount of water discharged from the plating recovery tank to 10 to 50% of the total amount of water in the plating recovery tank is not particularly limited. For example, two electrodes are provided in the plating recovery tank to make a constant A power source that is energized by a voltage or a constant current, an electric valve that operates by draining water and water injection, and the like are energized to the plating recovery tank, and the operation of the drain valve and the water-filled electric valve is controlled by the measured current value or potential value.

Specifically, for example, the electrodes provided in the plating recovery tank are energized at a constant voltage or a constant current, and the liquid contained in the plating recovery tank is previously formed to indicate a current value or a potential value, and is contained in the contained liquid. The calibration curve of the relationship between the concentration of the noble metal ions is energized at a constant voltage or a constant current between the electrodes provided in the plating recovery tank, and the current value or potential value between the electrodes is measured, and the obtained measured value and the above calibration curve are obtained. Based on the basis, the precious metal ion concentration of the receiving liquid in the plating recovery tank is quantified, and when the quantitative value obtained reaches a predetermined set value, the plating recovery tank is drained and/or water-filled by the plating recovery tank. The concentration of noble metal ions in the contained liquid is maintained at a high concentration in a certain range.

As the electrode, an electrode made of a Pt-plated Ti material, an Ir-sintered Ti material, or a fat-grained iron material which is not eluted at the time of increasing the current density is preferably used in the anode, and the cathode is preferably made of a Ti material or a SUS material. Or the electrode made of fat iron. Further, the shape of the electrode may be selected from a flat plate, a round bar, a cylinder, a mesh, etc., but it is more preferably a round bar or a cylinder in consideration of the electrode orientation at the time of mounting.

When the calibration curve is created and the plating recovery tank is actually energized to measure the current value or the potential value, the electrode shape, the electrode length, the distance between the electrodes, and the applied voltage of the electrode provided in the plating recovery tank are It is suitable for the conductivity of the plating drainage of the plating recovery tank. The electrical conductivity of the plating drainage includes the electrical conductivity of the entire plating drainage of noble metal ions and other electrolytes, and if the concentration of the noble metal ions is high, the electrical conductivity becomes high. When the slope of the precious metal ion concentration-current value curve of the plating drainage is large, the electrode diameter is small for a relatively low voltage application, and the electrode can be shortened to obtain a wide interelectrode distance. On the other hand, when the slope is small, for a relatively high voltage application, the electrode diameter is large, the electrode can be lengthened, a wide interelectrode distance is obtained, and the slope is adjusted. For example, when the applied voltage is set to 12 to 24 V, the current value corresponding to the upper limit value of the noble metal ion concentration can be set to 200 to 800 mA, and the current value corresponding to the lower limit value of the noble metal ion concentration can be set to 100 to 500 mA. It is preferable to select an electrode condition in which the difference value between the above-described upper and lower values of the noble metal ion concentration and the lower limit value can be managed in the range of 100 to 300 mA.

Drainage and/or water injection in the plating recovery tank. For example, the electric valve for drainage and water injection is operated simultaneously, and the electric valve for drainage is actuated. After the drainage is completed, the electric valve for water injection is actuated, and the electric valve for water injection in the drainage is used. The manner of actuation, etc., is performed by the control panel being automatically controlled. Further, instead of the electric valve, a solenoid valve or the like having the same function can be used.

In the method of simultaneously operating the electric valve for water discharge and water injection, if the current value of the liquid contained in the plating recovery tank reaches the set upper limit value, the electric valve for draining and water injection is simultaneously operated, and if the set is reached at the same time, The lower limit value is used to stop the electric valve for draining and water injection. The upper limit and the lower limit of the precious metal ion concentration are managed by controlling the current value of the liquid in the plating tank and controlling the period of drainage and water injection.

When the electric valve for the water discharge is operated, and the electric valve for the water injection is activated, if the current value of the liquid contained in the plating recovery tank reaches the set upper limit value, only the electric valve for draining is actuated, and the water is drained to The lower limit water level. At this time, the current value of the contained liquid did not change. If the drainage is completed, then the water injection is actuated by the electric valve, and if the water injection reaches the full water level, it stops. By controlling the current value of the liquid in the plating tank, controlling the drainage period, and managing the upper limit of the precious metal ion temperature, the displacement and the water injection amount are managed by the water level measurement, and the lower limit of the precious metal ion concentration is managed. value.

When the electric current of the liquid in the plating recovery tank reaches the set upper limit value, the electric valve for draining is actuated, and the electric valve for water injection is actuated in the drain. When the current value reaches the set lower limit value, the operation of the electric valve for drainage and water injection is stopped, and the water injection system is completed. The upper limit and the lower limit of the precious metal ion concentration are managed by controlling the current value of the liquid in the plating tank and controlling the period of drainage and water injection.

In the present invention, the precious metal of the noble metal ion of the object to be recovered is Au, Pd, Ag, Pt or Rh. Therefore, the type of the plating solution to be treated by plating the workpiece is a plating solution containing at least one of Au, Pd, Ag, Pt, and Rh, and may contain the noble metal and Ni, Co, Fe, An alloy plating solution of non-noble metal such as Zn. Further, examples of the plating method include cyan-based plating, non-cyanide plating, electrolytic plating, and electroless plating. Further, the plating solution contained in the plating tank is usually a noble metal ion concentration of 1 to 70 g/L.

Hereinafter, an example of an embodiment in which the concentration of the noble metal in the plating liquid in the plating recovery tank and the plating washing tank is maintained in the practice of the present invention will be described.

[Embodiment 1]

The plated Au liquid (manufactured by Electroplating Engineering (EEJA), trade name: Temperex MLA100; Au6 to 10 g/L) was used to set the water temperature of the liquid in the plating recovery tank at 50 °C. The upper limit of the Au ion concentration of the contained liquid is set to 50 to 59 mg/L, and the lower limit is set to 34 to 43 mg/L, and the electrode, the electrode shape, the electrode length, and the length of the electrode provided in the plating recovery tank are In the case of the most suitable condition for the distance between the electrodes and the applied voltage, if the applied voltage is 24 V, the current value indicating the upper limit of the Au ion concentration is 350 mA, and the current value indicating the lower limit value is 250 mA, and the Au ion concentration is The difference between the upper limit value and the lower limit management value is the most suitable electrode to be managed in the range of 100 mA by current value, and is an anode formed of a Pt-plated Ti material, a cathode formed of a Ti material, and an example of a round bar. The shape, the electrode diameter Φ 15 mm, the electrode length 23 mm, and the interelectrode distance 35 mm.

When the drainage and water injection of the plating recovery tank are performed simultaneously by the electric valve for drainage and water injection, when the upper limit value is 350 mA, the electric valve for drainage and water injection is simultaneously operated, and when the lower limit value is reached At 250 mA, the operation of the electric valve for draining and water injection is stopped. Therefore, the Au ion concentration to be drained is in the range of 50 to 59 mg/L of the upper limit concentration and 34 to 43 mg/L of the lower limit concentration, and 20% of the contained liquid in the plating recovery tank is exchanged. The Au ion concentration of the plating solution adhering to the plating material to be washed in the plating recovery tank is 59 mg/L at the maximum, and the Au concentration is diluted in the plating bath by diluting the adhesion liquid with water. Maintain a low concentration below 10 mg/L. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 44 to 46 ° C.

The electrolytic recovery of the high-concentration Au ions contained in the plating drainage from the plating recovery tank is a cycle treatment capacity of about 200 L using an anode made of an Ir sintered Ti material and a cathode electrode made of a Ti material. The electrolysis recovery device (manufactured by Tanaka Kikin Metal Co., Ltd.: MINI Recover Cell) collects Au ions at an electrolytic density of 130 to 200 mA/dm ² .

The resin of the low-concentration Au ion contained in the plating liquid of the waste liquid after the electrolytic recovery and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with an anion exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Au ions.

The concentration of Au ions remaining after the recovery treatment in the present embodiment is less than 0.2 mg/L.

[Embodiment 2]

When the plating treatment is performed using the Au plating solution (trade name: Temperex 8400; Au3 to 5 g/L), the water temperature of the storage liquid in the plating recovery tank is set to 50 ° C, and the liquid is contained. The upper limit of the Au ion concentration is set to 50 to 63 mg/L, and the lower limit is set to 33 to 42 mg/L. The electrode, the electrode shape, the electrode length, the distance between the electrodes, and the external electrode are provided in the plating recovery tank. In the case of the most suitable condition of the voltage, when the applied voltage is 24 V, the current value indicating the upper limit value of the Au ion concentration is 370 mA, and the current value indicating the lower limit value is 270 mA, and the upper limit value of the Au ion concentration. The difference between the lower limit management value and the current value indicates the most suitable electrode to be managed in the range of 100 mA, which is an anode formed of Pt-plated Ti material, a cathode formed of a Ti material, and an example of a round bar shape and an electrode diameter Φ. 15mm, electrode length 23mm, pole distance 35mm.

In the same manner as in the first embodiment, when the drainage and water injection for the drainage and the water injection are simultaneously performed, when the water is drained and the water is injected, when the water is at the upper limit of 370 mA, the electric valve for drainage and water injection is simultaneously activated. When the 270 mA of the lower limit value is reached, the operation of the electric valve for drainage and water injection is stopped. Therefore, the Au ion concentration to be drained is in the range of 50 to 63 mg/L of the upper limit concentration and 33 to 42 mg/L of the lower limit concentration, and 20% of the contained liquid in the plating recovery tank is exchanged. The Au ion concentration of the plating solution adhering to the plating material to be washed in the plating recovery tank is 63 mg/L at the maximum, and the Au concentration is diluted in the plating bath by diluting the adhesion liquid with water. Maintain a low concentration below 10 mg/L. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 44 to 46 ° C.

The electrolytic recovery of the high-concentration Au ions contained in the plating drainage from the plating recovery tank is a cycle treatment capacity of about 200 L using an anode made of an Ir sintered Ti material and a cathode electrode made of a Ti material. The electrolysis recovery device (manufactured by Tanaka Kikin Metal Co., Ltd.: MINI Recover Cell) collects Au ions at an electrolytic density of 130 to 200 mA/dm ² .

The resin of the low-concentration Au ion contained in the plating liquid of the waste liquid after the electrolytic recovery and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with an anion exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Au ions.

The concentration of Au ions remaining after the recovery treatment in the present embodiment is less than 0.2 mg/L.

[Embodiment 3]

When the plating treatment is performed using the Au plating solution (trade name: Autrobond TN; Au1 to 3 g/L), the water temperature of the storage liquid in the plating recovery tank is set to 50 ° C, and the liquid is contained. The upper limit of the Au ion concentration is set to 28 to 95 mg/L, and the lower limit is set to 17 to 74 mg/L, and the electrode, the electrode shape, the electrode length, the distance between the electrodes, and the external electrode are provided in the plating recovery tank. In the case of the most suitable condition of the voltage, when the applied voltage is 12 V, the current value indicating the upper limit value of the Au ion concentration is 450 mA, and the current value indicating the lower limit value is 350 mA, which is the upper limit of the Au ion concentration. The difference between the value and the aforementioned lower limit management value is the most suitable electrode to be managed in the range of 100 mA in terms of current value, and is an anode formed of Pt-plated Ti material, a cathode formed of Ti material, and an example of a round bar shape and an electrode diameter. Φ 15mm, electrode length 23mm, pole distance 35mm.

In the same manner as in the first embodiment, when the drainage and the water injection electric valve are simultaneously operated to perform the drainage and water injection of the plating recovery tank, when the upper limit is reached at 450 mA, the electric valve for drainage and water injection is simultaneously activated. When it reaches 350 mA of the lower limit value, the operation of the electric valve for draining and water injection is stopped. Therefore, the Au ion concentration to be drained is in the range of 28 to 95 mg/L of the upper limit concentration and 17 to 74 mg/L of the lower limit concentration, and 20% of the contained liquid in the plating recovery tank is exchanged. The Au ion concentration of the plating solution adhering to the plating material to be washed in the plating recovery tank is 95 mg/L at the maximum, and the Au concentration is diluted in the plating bath by diluting the adhesion liquid with water. Maintain a low concentration below 10 mg/L. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 44 to 46 ° C.

The electrolytic recovery of the high-concentration Au ions contained in the plating drainage from the plating recovery tank is a cycle treatment capacity of about 200 L using an anode made of an Ir sintered Ti material and a cathode electrode made of a Ti material. The electrolysis recovery device (manufactured by Tanaka Kikin Metal Co., Ltd.: MINI Recover Cell) collects Au ions at an electrolytic density of 130 to 200 mA/dm ² .

The resin of the low-concentration Au ion contained in the plating liquid of the waste liquid after the electrolytic recovery and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with an anion exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Au ions.

The concentration of Au ions remaining after the recovery treatment in the present embodiment is less than 0.2 mg/L.

[Embodiment 4]

When the plating treatment is performed using a Pd-plated liquid (manufactured by EEJA Co., Ltd., trade name: Palladex 100; Pd 25 to 30 g/L), the water temperature of the liquid contained in the plating recovery tank is set to 50 ° C, and the liquid is contained. The upper limit of the Pd ion is set to 129 to 157 mg/L, and the lower limit is set to 38 to 77 mg/L. The electrode, the electrode shape, the electrode length, the distance between the electrodes, and the applied voltage are provided in the plating recovery tank. In the first case of the most suitable condition, when the applied voltage is 12V, the current value indicating the upper limit value of the Pd ion concentration is 550 mA, and the current value indicating the lower limit value is 450 mA, and the upper limit value of the Pd ion concentration and The difference between the lower limit management values and the current value indicates the most suitable electrode to be managed in the range of 100 mA, which is an anode formed of a Pt-plated Ti material, and a cathode electrode formed of a Ti material, exemplified by a round bar shape and an electrode diameter Φ. 15mm, electrode length 23mm, pole distance 45mm.

When the drainage is completed, the water injection is operated by the electric valve, and when the drainage and the water injection of the plating recovery tank are performed, when the 550 mA of the above upper limit is reached, the electric valve for drainage is actuated, and when the water is discharged, the amount of water is discharged. At 40% of the time, the water injection is actuated by the electric valve and stops when it is full. Therefore, the Pd ion concentration to be drained is in the range of 129 to 157 mg/L of the upper limit concentration, and the Pd ion concentration of the adhering liquid adhered to the plating target treated by the plating recovery tank is at most 157 mg/L. In the plating washing tank, the Pd ion concentration is maintained at a low concentration of 10 mg/L or less by diluting the adhering liquid with water. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 40 to 42 ° C.

The electrolytic recovery of high-concentration Pd ions contained in the plating drainage from the plating recovery tank is performed by using an anode formed of a Pt-plated Ti material and a cathode electrode formed of a Ti material. A 200 L electrolytic recovery device (manufactured by Tanaka Kiyoshi Metal Co., Ltd.: MINI Recover Cell) was used to recover Pd ions at an electrolytic density of 100 to 270 mA/dm ² .

The resin from the low-concentration Pd ions contained in the plating liquid of the waste liquid after the electrolytic recovery and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with a chelating resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Pd ions.

The Pd ion concentration remaining after the recovery treatment in the present embodiment is less than 0.5 mg/L.

[Embodiment 5]

When the plating treatment is performed using an Ag plating solution (manufactured by NE Chemcat Co., Ltd., trade name: AG-10; Ag 50 to 70 g/L), the water temperature of the storage liquid in the plating recovery tank is set to 50 ° C. The upper limit of the Ag ion concentration of the contained liquid is set to 148 to 195 mg/L, and the lower limit is set to 49 to 83 mg/L. The electrode, the electrode shape, the electrode length, and the distance between the electrodes are set in the plating recovery tank. In the case of the most suitable condition of the applied voltage, when the applied voltage is 12 V, the current value indicating the upper limit of the Ag ion concentration is 650 mA, and the current value indicating the lower limit value is 550 mA, which is the Ag ion concentration. The difference between the upper limit value and the lower limit management value is the most suitable electrode to be managed in the range of 100 mA. The anode is made of Pt-plated Ti material, and the cathode electrode made of Ti material is illustrated as a round bar shape. The electrode diameter is Φ 15 mm, the electrode length is 23 mm, and the interelectrode distance is 55 mm.

In the same manner as in the fourth embodiment, the drainage and the water injection in the plating recovery tank are operated by the electric valve for drainage, and when the water injection is performed by the electric valve after the completion of the drainage, the water is discharged to the upper limit of 650 mA. When the electric valve is actuated, when the water is discharged 50%, the water injection is actuated by the electric valve and stops when the water is full. Therefore, the Ag ion concentration to be drained is in the range of 148 to 195 mg/L of the upper limit concentration, and the Ag ion concentration of the adhering liquid adhered to the plating target treated by the plating washing tank is 195 mg/L at the maximum. In the plating washing tank, the Ag concentration was maintained at a low concentration of 10 mg/L or less by diluting the adhering liquid with water. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 39 to 41 ° C.

The electrolytic recovery of the high-concentration Ag ions contained in the plating drainage from the plating recovery tank is a cycle treatment capacity of about 200 L using an anode made of an Ir sintered Ti material and a cathode electrode made of a Ti material. The electrolytic recovery device (MINI Recover Cell, manufactured by Tanaka Kikin Metal Co., Ltd.) was used to recover Ag ions at an electrolytic density of 130 to 200 mA/dm ² .

The resin of the low-concentration Ag ion contained in the plating liquid of the waste liquid after electrolysis and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with an anion exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Ag ions.

The Ag ion concentration remaining after the recovery treatment in the present embodiment is less than 0.2 mg/L.

[Embodiment 6]

When the plating treatment is performed using a Pt-plated liquid (manufactured by EEJA Co., Ltd., trade name: Preciousfab Pt100; Pt10 to 14 g/L), the water temperature of the liquid contained in the plating recovery tank is set to 50 ° C, and the liquid is contained. The upper limit of the Pt ion concentration is set to 96 to 120 mg/L, and the lower limit is set to 45 to 63 mg/L. The electrode, the electrode shape, the electrode length, the distance between the electrodes, and the external electrode are provided in the plating recovery tank. In the case of the most suitable condition of the voltage, when the applied voltage is 15 V, the current value indicating the upper limit of the Pt ion concentration is 500 mA, and the current value indicating the lower limit value is 400 mA, which is the upper limit of the Pt ion concentration. The difference between the value and the aforementioned lower limit management value is the most suitable electrode to be managed in the range of 100 mA by the current value, and is an anode formed of Pt-plated Ti material, a cathode electrode formed of Ti material, and an example of a round bar shape and an electrode. The diameter is Φ 15mm, the electrode length is 23mm, and the distance between the poles is 40mm.

When draining and water-injecting the plating recovery tank by means of an electric valve for water injection in the drain, when the upper limit value is 500 mA, the electric valve for draining is actuated, and the water-filled water is actuated by the electric valve to reach the lower limit. When the value is 400 mA, the operation of the electric valve for draining and water injection is stopped. Therefore, the Pt ion concentration to be drained is in the range of 96 to 120 mg/L of the upper limit concentration and 45 to 63 mg/L of the lower limit concentration, and 40% of the contained liquid in the plating recovery tank is exchanged. The Pt ion concentration of the plating solution adhered to the plating treatment tank to be cleaned is 120 mg/L at the maximum, and is maintained at 10 mg by diluting the adhesion liquid with water in the plating washing tank. Low concentration below /L. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 40 to 42 ° C.

The electrolytic recovery of the high-concentration Pt ions contained in the plating drainage from the plating recovery tank is performed by using an anode formed of a Pt-plated Ti material and a cathode electrode formed of a Ti material. A 200 L electrolytic recovery device (manufactured by Tanaka Kiyoshi Metal Co., Ltd.: MINI Recover Cell) was used to recover Pt ions at an electrolytic density of 30 to 140 mA/dm ² .

The resin of low-concentration Pt ions contained in the plating liquid of the waste liquid after electrolysis and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with a cation exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Pt ions.

The Pt ion concentration remaining after the recovery treatment in the present embodiment is less than 0.5 mg/L.

[Embodiment 7]

When the plating treatment is performed using a Rh-containing liquid (manufactured by NE Chemcat Co., Ltd., trade name: RH221; Rh 3 to 5 g/L), the water temperature of the liquid contained in the plating recovery tank is set to 50 ° C, and the liquid is contained. The upper limit of the Rh ion concentration is set to 42 to 60 mg/L, and the lower limit is set to 16 to 32 mg/L, and the electrode, the electrode shape, the electrode length, the distance between the electrodes, and the external electrode are provided in the plating recovery tank. In the case of the most suitable condition of the voltage, when the applied voltage is 24 V, the current value indicating the upper limit value of the Rh ion concentration is 450 mA, and the current value indicating the lower limit value is 350 mA, which is the upper limit of the Rh ion concentration. The difference between the value and the aforementioned lower limit management value is the most suitable electrode to be managed in the range of 100 mA by the current value, and is an anode formed of Pt-plated Ti material, a cathode electrode formed of Ti material, and an example of a round bar shape and an electrode. The diameter is Φ 15mm, the electrode length is 23mm, and the distance between the poles is 35mm.

In the same manner as in the sixth embodiment, when the drainage and the water injection of the plating recovery tank are performed by the water injection in the drainage, when the upper limit value is 450 mA, the drain electric valve is actuated, and the water injection in the drainage is actuated by the electric valve. When it reaches 350 mA of the lower limit value, the operation of the electric valve for draining and water injection is stopped. Therefore, the Rh ion concentration to be drained is in the range of 42 to 60 mg/L of the upper limit concentration and 16 to 32 mg/L of the lower limit concentration, and 30% of the contained liquid in the plating recovery tank is exchanged. The Rh ion concentration of the plating solution adhered to the plating treatment tank to be washed is up to 60 mg/L, and is maintained at 10 mg by diluting the adhesion liquid with water in the plating washing tank. Low concentration below /L. The water temperature of the water injection is about 20 ° C, and the water temperature of the plating recovery tank during continuous operation is 42 to 44 ° C.

The electrolytic recovery of the high-concentration Rh ion contained in the plating drainage from the plating recovery tank is performed by using an anode formed of a Pt-plated Ti material and a cathode electrode formed of a Ti material. A 200 L electrolytic recovery device (manufactured by Tanaka Kiyoshi Metal Co., Ltd.: MINI Recover Cell) was used to recover Rh ions at an electrolytic density of 30 to 140 mA/dm ² .

The resin from the low-concentration Rh ion contained in the plating liquid of the waste liquid after electrolysis and the plating washing tank is recovered, and the same resin can be used, and an ion exchange resin device filled with a cation exchange resin is used. Tanaka Precious Metal Industry Co., Ltd.: Eagle RE) to recover Rh ions.

The Rh ion concentration remaining after the recovery treatment in the present embodiment is less than 0.5 mg/L.

[Comparative form 1]

The amount of water discharged from the plating recovery tank of the third embodiment is set to 60% of the total amount of water in the plating recovery tank, and is drained, and the upper limit and the lower limit of the Au ion concentration of the storage liquid are set. However, in 60% of the drainage, the water temperature of the plating recovery tank is lower than 35 ° C, and the elution efficiency of excess precious metal ions or salt components attached to the plated material to be treated is lowered, and mold or bacteria are generated. Reproduction, the quality of the plated material to be treated is reduced due to the deterioration in quality.

[Comparative Form 2]

The amount of water discharged from the plating recovery tank of the fifth embodiment is set to 5% of the full amount of water in the plating recovery tank, and the upper limit and the lower limit of the Ag ion concentration of the storage liquid are set. However, in 5% of the drainage, a sufficient difference cannot be established in the range of the upper limit value and the lower limit value, and the current value of the Ag ion concentration cannot be managed. As a result, the Ag ion concentration exceeds 800 mg/L, and the adhesion is adhered. The efficiency of recovering excess precious metal ions or salt components in the plated material to be treated is lowered, and the yield of the plated workpiece due to the deterioration in quality is lowered. Further, in the plating cleaning tank, the Ag ion concentration exceeds the recovery ability of the ion exchange resin device, and the recovery rate of the precious metal is lowered.

Claims (3)

A method for recovering precious metal ions from a plating drainage, characterized in that the amount of water discharged from the plating recovery tank is within a range of 10 to 50% of the total amount of water in the plating recovery tank, and is recovered by plating. In the tank, the amount of the impregnation of the material to be treated is ensured, and the concentration of the noble metal ions of the liquid in the plating recovery tank is maintained at a high concentration of 10 to 200 mg/L, and the plating is cleaned in the tank. The precious metal ion concentration of the liquid is maintained at a low concentration of 10 mg/L or less, and the plating drainage from the plating recovery tank is maintained at a high concentration of 10 to 200 mg/L for the concentration of the noble metal ions, and the electrolytic recovery method and the resin recovery method are used. Or the activated carbon adsorption recovery method to recover precious metal ions, and the plating drainage from the plating cleaning tank maintained at a low concentration of noble metal ions at a concentration lower than 10 mg/L is recovered by a resin recovery method or an activated carbon adsorption recovery method. Precious metal ions. A method for recovering noble metal ions according to the first aspect of the invention, wherein the noble metal ion is selected from the group consisting of ions of one or more noble metals selected from the group consisting of Au, Pd, Ag, Pt, and Rh. A method for recovering precious metal ions according to the first or second aspect of the patent application, wherein a current is applied between the electrodes provided in the plating recovery tank at a constant voltage or a constant current, and the liquid in the plating recovery tank is previously expressed. A calibration curve for the relationship between the current value or the potential value and the concentration of the noble metal ions contained in the contained liquid is constant voltage or constant between the electrodes provided in the plating recovery tank The current is supplied to the flow, and the current value or the potential value between the electrodes is measured. Based on the obtained measured value and the calibration curve, the precious metal ion concentration of the liquid contained in the plating recovery tank is quantified, and the noble metal ion concentration is maintained at a constant value. range.