JP2000199086A - Treatment of etching waste solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an etching soln. increased in etching efficiency in such a manner that working quality in etching treatment is satisfactorily maintained. SOLUTION: This method has a 1st stage in which a part of an etching waste soln. is discharged and is added with iron powder, the oxidation-reduction potential ORP is conrolled to -350 to +100 mV, and ferric ions contained therein are reduced into ferrous ions, a 2nd stage in which the treating soln. obtd. in the 1st stage is moeover brought into contact with iron powder to control the oxidation-reduction potential in the range of -550 to -350 mV, and nonferrous metallic ions are removed to obtain a refined soln. and a 3rd stage in which the refined soln. is mixed with a part or the whole of the etching waste soln., and after that, gaseous chlorine is blown therein to obtain an etching soln. enriched with ferric ions, the quantity of the etching waste soln. to the refined soln. mixed in the 3rd stage to be poured is controlled to control the concn. of nonferrous metallic ions, by which the etching soln. having a reaction rate corresponding to the object to be etched can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating an etching waste liquid containing iron chloride as a main component, which is generated after etching a shadow mask for a cathode ray tube, a lead frame for a semiconductor, or the like.

[0002]

2. Description of the Related Art In the manufacturing process of a shadow mask or the like, iron-
A thin metal plate made of a nickel alloy or the like is immersed in an etching solution to dissolve a portion of the thin metal plate that is not masked with a resist film, and is processed into a desired fine pattern. As the dissolution of such a metal such as an iron-nickel alloy progresses, ferric ions in the etching solution become first ions.
While being reduced to iron ions, the concentration of nickel ions gradually increases, and the etching ability is reduced beyond its limit, and is discharged from an etching factory as an etching waste liquid. Conventionally, when regenerating such an etching waste liquid, the etching waste liquid is carried out from an etching factory using a tank lorry or the like, and is carried into a waste liquid processing center for collecting and managing the etching waste liquid, where the etching treatment is performed. Metals other than the eluted iron, such as nickel,
Non-ferrous metals such as copper, chromium, and cobalt are reduced and removed, and the reduced ferric ion is recovered to a predetermined concentration, and is transported as an etchant to an etching factory.

[0003]

However, the etching solution obtained by using the conventional etching waste liquid processing method has a too high reaction rate when the etching solution is fresh and has a sufficient etching ability. There has been a problem that it is difficult to maintain good processing quality by lowering the dimensional accuracy of the object to be etched or causing irregularities or the like based on the difference in the amount of elution at the end of the resist film. The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for treating an etching waste liquid capable of producing an etching solution with improved etching efficiency while maintaining good processing quality in the etching process. Aim.

[0004]

According to the present invention, there is provided a method for treating an etching waste liquid according to the present invention, wherein a part of the etching waste liquid discharged from an etching factory is taken out, iron powder is added, and the oxidation-reduction potential ORP is reduced. A first step of reducing the ferric ion contained to -350 to +100 mV, which is a range in which the optimum efficiency of the treatment is obtained, and a treatment liquid obtained in the first step is further mixed with iron powder. By contacting, the oxidation-reduction potential ORP is adjusted to -550 to -350 mV, which is a range in which the reduction efficiency of non-ferrous metal ions is increased,
A second step of removing the contained non-ferrous metal ions to obtain a purified liquid, so that in the second step, the reduction reaction of the non-ferrous metal ions is not hindered by the presence of the ferrous ions, As a result, the reduction efficiency of non-ferrous metal ions can be improved. In this way, after the non-metal ions are removed and a part or all of the remainder of the etching waste liquid is mixed with the purified liquid enriched with ferrous ions, chlorine gas is blown therein to enrich the ferric ions in the liquid. Since the method includes the third step of obtaining the etched etchant, a predetermined level of etching ability can be added to the etchant. Furthermore, since the amounts of the purified liquid and the etching waste liquid mixed in the third step are controlled to adjust the non-ferrous metal ion concentration of the etching liquid and produce an etching liquid having a reaction rate adapted to the etching target, During the etching process, an excessive etching rate causes troubles such as elution of the etched surface so that the etched surface is eclipsed, causing irregularities, or difficulties in controlling the reaction rate and impairing the processing dimensional accuracy. Can be prevented, and the efficiency of the etching process can be maintained at a predetermined level.

If the oxidation-reduction potential of the processing solution in the first step is lower than -350 mV, the reduction reaction tends to proceed excessively, so that not only the reduction reaction from ferric ions to ferrous ions, but also In the second step, the non-ferrous metal ions to be reduced and separated are reduced, and it becomes difficult to efficiently perform the non-ferrous metal ion reduction separation operation. Conversely, if the oxidation-reduction potential exceeds +100 mV, the reduction of ferric ions becomes insufficient, and the subsequent operation of reducing and separating non-ferrous metal ions becomes difficult. Further, if the oxidation-reduction potential of the treatment liquid in the second step is to be lowered to less than -550 mV, an excessive iron powder is required, and in conjunction with this, the hydrogen ion concentration pH tends to increase,
This facilitates the generation of hydroxide. On the other hand, when the oxidation-reduction potential exceeds -350 mV, that is, when the oxidation-reduction potential is close to zero, reduction of non-ferrous metal ions becomes insufficient, which is not preferable.

[0006] Further, the pH value of the hydrogen ion concentration index pH of the treatment solution treated in the second step is 1.5 to 3 which is a specific range in which the reduction reaction of non-ferrous metal ions in the second step can be performed without excess or shortage. .0 to perform the processing. Thereby, the production efficiency of the finally obtained purified liquid can be maintained in an appropriate range. If the hydrogen ion concentration index in the second step is lower than 1.5, the amount of free acid increases, and this acid reacts with iron powder to inhibit the reduction reaction of non-ferrous metal ions. When the hydrogen ion concentration index exceeds 3.0, insoluble components such as hydroxides are easily generated.

Further, the non-ferrous metal contains nickel, and the nickel ion concentration of the etching solution is set to a specific range to suppress the etching rate from becoming excessive during the etching process and to suppress the occurrence of processing defects. It is also possible to further improve the efficiency of the etching process. When the non-ferrous metal ions are nickel ions, it is preferable that the nickel ion concentration of the regenerated etching solution be in the range of 10 to 25 g / liter, preferably 15 to 20 g / liter for the following reasons. That is, if the nickel ion concentration is less than 10 g / liter, the rate of the etching reaction becomes too high, and the processing failure of the product is easily caused. Conversely, if the nickel ion concentration exceeds 25 g / liter, the rate of the etching reaction is greatly reduced, and the etching efficiency is deteriorated.

When a non-ferrous metal contains copper, as in the case of processing a lead frame for a semiconductor containing copper, the copper ion concentration of the etching solution is set to a specific range, that is, 5-1.
By adjusting the amount to 00 g / liter, it is also possible to suppress the occurrence of processing defects during the etching processing. If the copper ion concentration of the etching solution is less than 5 g / liter, the rate of the etching reaction is reduced, and local excessive elution of the etching target cannot be effectively prevented. Conversely, if the copper ion concentration exceeds 100 g / liter, the etching reaction is greatly inhibited, causing trouble.

[0009] The treatment of the etching waste liquid is performed in a waste liquid treatment facility located at or near the site where the etching process is performed, and a pipe is connected between the waste liquid tank and the waste liquid treatment device in the site where the etching process is performed. Connection may be used. This makes it possible to reduce the transportation cost and to efficiently operate the etching equipment including the waste liquid treatment as compared with a case where the etching waste liquid is transported using a tank truck or the like. Furthermore, using a head difference between the waste liquid tank and the waste liquid treatment equipment or a pumping means using a pump,
The etching waste liquid can be supplied to a waste liquid treatment facility via a pipe. Thus, when the head difference is used, it is economical without using electric energy or the like, and when the pump is used, it is efficiently used without depending on the height difference between the retained liquid in the waste liquid tank and the waste liquid treatment equipment. An etching waste liquid can be supplied.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is an explanatory view of an etching equipment to which a method for treating an etching waste liquid according to an embodiment of the present invention is applied, FIG. 2 is an explanatory view of an iron powder stirring tank in the etching equipment, and FIG. FIG. 4 is an explanatory view of a fluidized bed tank, FIG. 4 is an explanatory view schematically showing a relationship between an etching rate and a nickel ion concentration in an etching solution, and FIG. 5 is an explanatory view showing a modification of an apparatus applied to a reduction apparatus and a denickelization apparatus. FIG.

As shown in FIG. 1, an etching facility 10 to which an etching waste liquid treatment method according to an embodiment of the present invention is applied includes an etching plant 11 for etching an object to be etched and a place adjacent to this site. And a waste liquid treatment facility 13 for disposing the etching waste liquid discharged via the pipe 12. The etching target processed in the etching factory 11 is a metal material for a shadow mask made of an iron-nickel alloy containing iron as a main component and about 36% by weight of nickel (an example of a non-ferrous metal).

The etching factory 11 includes an etching apparatus 14 for etching an object to be etched into a predetermined shape pattern using an etching solution, and a waste liquid tank 15 for temporarily storing an etching waste liquid after the etching processing. have. Further, in the etching factory 11, a predetermined ratio of all or a part of the etching waste liquid taken out from the waste liquid tank 15, a replenisher containing 200 to 350 g / l of ferric ions and the purified liquid treated in the waste liquid treatment equipment 13 are provided. And a mixing tank 16 for mixing. As a result, non-ferrous metal ions containing nickel, copper, cobalt, chromium, etc.,
The concentration of iron ions can be set within a predetermined range. In addition, the etching waste liquid taken out from the waste liquid tank 15 is transported using a mixing tank 16, a head difference between the waste liquid processing equipment 13 and the waste liquid tank 15, or a pumping means provided by a pump (not shown) provided in the pipe 12. The predetermined amount of the etching waste liquid can be efficiently transported appropriately by operating a valve or the like. Further, the etching plant 11 has a chlorine gas blowing device 17 for oxidizing ferrous ions in the mixed solution mixed in the mixing tank 16 into ferric ions, and a solid insoluble in the solution treated with chlorine gas. And a filtration device 18 for removing the fraction (SS) using a diatomaceous earth filter. With these devices, the concentration of ferric ions and the concentration of non-ferrous metal ions in the solution are adjusted to the ranges required for the etching treatment, so that a purified and regenerated etching solution can be obtained.

The waste liquid treatment equipment 13 is provided with a reducing device 19 for mainly reducing ferric ions in the etching waste liquid.
And a nickel removal device (Ni removal) for mainly reducing and removing nickel ions in the treatment liquid treated by the reduction device 19.
Device) 20 and a purifying device 21 for separating and purifying solids in the liquid obtained by the nickel removing device 20. As shown in FIG. 2, the reducing device 19 is an iron powder stirring tank 22.
have. The iron powder stirring tank 22 includes a substantially cylindrical bottomed container 23 for holding a predetermined amount of iron powder therein, and agitates the iron powder and the etching waste liquid to be charged into a substantially central portion of the container 23. Stirring blades 24 are provided. The stirring blade 24 is rotated using a motor (not shown) to bring the etching waste liquid into contact with the iron powder in a fluid state, and the elution of iron, that is, the ionization of iron causes the second waste in the liquid.
Iron ions can be reduced to ferrous ions. The iron powder stirring tank 22 is provided with a sensor 25 for measuring the oxidation-reduction potential and the hydrogen ion concentration in the treatment liquid, and constantly monitors the state in the liquid to measure the measured oxidation-reduction potential. And when the hydrogen ion concentration is out of the predetermined range, dilution water or etching waste liquid is added, or the stirring blade 2
4 can be maintained in a predetermined range by adjusting the rotation speed or the like.

The nickel removing apparatus 20 includes a fluidized bed tank 26 having a structure as shown in FIG. The fluidized-bed tank 26 used here may be replaced by a tank having the same configuration as the iron powder stirring tank 22. The fluidized-bed tank 26 is, for example, a substantially cylindrical reaction vessel divided into five parts, a first section 27 to a fifth section 31, each having a different horizontal cross-sectional area from top to bottom. A pump 32 for forming a fluidized bed in which iron powder floats in the etching waste liquid in 26, and a circulation pipe 33 connected to the pump 32 are provided. Here, the first, third and fifth partition portions 27, 2
Zones 9 and 31 each have a constant horizontal cross-sectional area. The second and fourth partitions have side surfaces whose diameters are reduced downward, so that the horizontal cross-sectional area decreases. Thus, the characteristic values such as the density of the liquid to be processed in each partition can be distinguished step by step, and the processing liquid having the desired characteristics can be extracted by selecting each partition as needed. In addition, the fluidized bed tank 26 is provided with a sensor 25a for measuring the oxidation-reduction potential and the hydrogen ion concentration of the liquid to be treated in the same manner as the iron powder stirring tank 22.

The refining apparatus 21 includes a centrifuge, which is generally called a decanter, which separates a solid content and a liquid by using a centrifugal action, a sedimentation tank which sediments the solid content and extracts a supernatant,
And a filtration device using a filter, and these can be used alone or in combination as needed. The purifying apparatus 21 also includes a hydrochloric acid dissolving tank and the like for dissolving a small amount of solid remaining after the purifying treatment using hydrochloric acid.

Next, a method of treating an etching waste liquid applied to the etching equipment 10 will be described. Here, FIG. 4 shows the ferric ion concentration in a predetermined range, for example, 15
It is explanatory drawing which showed typically the relationship between the etching rate at the time of eluting the etching object which consists of an iron-nickel alloy using the etching liquid of 0-300 g / liter, and the nickel ion concentration in an etching liquid. . In the sharp zone shown in FIG. 4, since the etching rate becomes excessive, a sharp projection is easily generated on the etched surface,
This indicates that the shape quality of the etching target subjected to the etching processing is out of the specified range. In the optimum zone, the nickel ion concentration in the etching solution is in an appropriate range, so that the etched surface is smooth and the etching rate is in a range in which the etching process can be precisely controlled. In the west zone, it is shown that the etching rate is reduced to a level where a practical etching process cannot be performed. Therefore, as is apparent from the figure, the nickel ion concentration in the regenerated etching solution is in the range of 10 to 25 g / liter, preferably 15 to 25 g / liter.
It can be seen that by adjusting the concentration to ２０20 g / liter, an etchant having a reaction rate suitable for the etching target can be obtained. In addition, depending on the type of the etching target, for non-ferrous metals other than nickel, such as copper and cobalt, the relationship between the etching rate and the ion concentration is experimentally measured to define each ion concentration. (For example, when the copper ion concentration is 5
１００100 g / liter) can be set individually. In the present embodiment, the nickel ion concentration of the finally obtained etching solution is set by adjusting the reaction conditions and the ratio of the mixed solution amount in each processing step so as to be the optimum zone determined in this manner. ing.

Hereinafter, a method for treating an etching waste liquid, in which the ferric ion concentration and the nickel ion concentration of the obtained etching solution are set within a range in which the etching process can be performed well, will be specifically described. In the first step, the waste liquid tank 15
Of the etching waste liquid taken out from the pipe through the pipe 12, for example, an average of 30 volume percent (range: 20 to 60)
An operation of supplying the etching waste liquid for the amount (percent by volume) to the reduction device 19 to reduce ferric ions in the liquid to ferrous ions is performed. That is, a predetermined amount of the etching waste liquid is charged into the iron powder stirring tank 22 provided in the reduction device 19, and the stirring blade 24 is rotated to mix the iron powder and the etching waste liquid for a predetermined time. At this time, the oxidation-reduction potential ORP measured using the sensor 25 is adjusted to a predetermined range (−350 to +100 m) by adjusting the amount of the dilution water or the additional etching waste liquid.
V). This makes it possible to efficiently obtain a processing solution enriched in ferrous ions.
In the case where the etching waste liquid contains copper ions in addition to nickel ions, part or all of the copper ions are reduced in the first step, and at the same time, ferric ions are reduced, and the next step is performed. By reducing nickel ions remaining in the second step, copper and nickel can be separated in the first and second steps, respectively.

In the next second step, first, a predetermined amount of iron powder is supplied from the upper end opening of the fluidized-bed tank 26 provided in the denickelizer 20, and then in the middle of the circulation pipe 33 or the fifth step. The processing liquid is supplied to the bottom of the partition 31 to fill the fluidized bed tank 26 with a predetermined amount of the processing liquid. Next, the fluidized bed tank 2
6 A part of the processing liquid is taken out from the upper first partition 27 and / or the second partition 28, and this processing liquid is supplied to the lowermost fifth partition 31 via the pump 32 to form a fluidized bed tank. 26
A fluidized bed in which iron powder flows and floats is formed. After a denickelization reaction in the fluidized bed for a predetermined time in this way,
A processing liquid from which nickel ions have been reduced and removed (hereinafter referred to as a reduction processing liquid) can be taken out of the first partition 27 and / or the second partition 28 and sent to the next step. The iron powder and the processing liquid are efficiently brought into contact with each other in the fluidized bed formed by the pump 32, and a processing liquid to be newly supplied is continuously supplied to the bottom of the fifth partition 31, so that the first partition It is also possible to continuously take out the reduction treatment liquid overflowing from the 27 and / or the second compartment 28.

The processing solution enriched with ferrous ions is further reduced with iron powder in the reducing device 19 to reduce non-ferrous metal ions in the solution to non-ferrous metal. That is, the liquid treated in the second step is circulated and supplied to the fluidized-bed tank 26 of the denickelizer 20, and brought into contact with iron powder in a fluidized state. At this time, the oxidation-reduction potential ORP and the hydrogen ion concentration coefficient pH measured using the sensor 25a are adjusted to a predetermined range (−550 to −3) by adjusting the circulation amount and the residence time of the treatment liquid.
50 mV, 1.5 to 3.0).
As a result, it is possible to obtain a reduction treatment liquid from which a predetermined amount of non-ferrous metal ions have been removed or removed. Next, this reduction treatment liquid is supplied to the purification device 21 to remove solid insolubles in the liquid, and to dissolve remaining fine particles using hydrochloric acid, to remove ferrous ions, ferric ions, The second step is completed by obtaining purified liquids each containing a nonmetal ion in a predetermined concentration, for example, in the range of 200 to 330 g / liter, 10 g / liter or less, and 3 g / liter or less.

In the subsequent third step, first, the purified liquid, the replenisher containing ferric chloride and the remaining 70% by volume of the etching waste liquid are mixed at a predetermined ratio using the mixing tank 16. By mixing, the concentration can be set to a predetermined nickel ion concentration, for example, a concentration range of 15 to 20 g / liter. The replenisher used here is
A solution (new solution) having a high etching ability containing substantially non-ferrous metal ions eluted by etching and mainly containing ferric ion, which is a component of ferric chloride, is used. It can also be set lower. In this case, it is also possible to increase the absorption amount and the absorption efficiency of the chlorine gas in the chlorine gas blowing device 17 and to improve the utilization efficiency of the chlorine gas produced secondarily. Then, the chlorine gas blowing device 17 blows chlorine gas into a mixture obtained by mixing the purified liquid, the replenisher and the remaining etching waste liquid to oxidize a part or all of the remaining ferrous ions into ferric ions. I do. The third step including the mixing operation in the mixing tank 16 and the oxidation operation in the chlorine gas blowing device 17 finally obtains an etchant having a predetermined ferric ion concentration and a nickel ion concentration. Can be. In the present embodiment, after the third step, the etchant is filtered using a filtration device 18 to remove the remaining solid insolubles, thereby increasing the commercial value of the etchant.

The reducing device 19 and the nickel removing device 2
For example, a fluidized bed agitation tank 40 as shown in FIG. 5 can be applied to 0 in addition to the apparatus such as the iron powder agitation tank 22 and the fluidized bed tank 26. The fluidized-bed stirring tank 40 is a container including three regions of the first to third partition portions 41 to 43 and a fluid medium supply portion 44 configured to have different horizontal cross-sectional areas in the vertical direction. In the fluidized bed stirring tank 40, the second
A partition 46 for separating a fluidized bed (hatched portion in the figure) of the iron powder formed by the partition 42 and the third partition 43 and a fluid medium supply 44 is provided. The processing liquid is supplied from supply ports 47 and 48 provided at the bottom and side of the fluid medium supply unit 44. A plurality of nozzles 49 called "twires" for dispersing and discharging a processing liquid or a circulating liquid serving as a fluid medium supplied from below the partitioning board 46 in the horizontal direction on the partitioning board 46 are arranged in a zigzag or grid pattern. Are located in Further, the first partition 41 has an outlet 50 for taking out an amount of fluid medium necessary for forming a fluidized bed, and a processing liquid outlet 51 for collecting a processing liquid from the first partition.
Are provided. Further, a pump 52 for supplying a circulating liquid (fluid medium) taken out from the processing liquid outlet 51 to the fluid medium supply unit 44 is provided. Thereby, the taken out circulating liquid is supplied to the circulating flow supply port 53 provided on the side surface of the fluidized medium supply unit 44 via the pump 52, and a circulating flow for fluidizing the iron powder in the tank is formed. It has become so.

The embodiment of the present invention has been described above.
The present invention is not limited to these embodiments, and all changes in conditions without departing from the gist are within the scope of the present invention. For example, in the present embodiment, a case has been described in which each of the devices for iron powder treatment applied to the reduction device and the denickelization device has a specific configuration, but the devices may have the same configuration. It is also possible to use these in combination. Although the case where nickel is used as the non-ferrous metal has been described, the present invention can be similarly applied to the case of non-ferrous metals such as copper, chromium, and cobalt.

[0023]

In the method for treating an etching waste liquid according to any one of the first to sixth aspects of the present invention, a part of the etching waste liquid discharged from the etching factory is taken out, iron powder is added, and the oxidation-reduction potential ORP is reduced. And reducing the ferric ion contained therein to ferrous ion, and further contacting the processing solution obtained in the first step with iron powder to reduce the oxidation-reduction potential ORP to non-ferrous A second step of adjusting the metal ion reduction efficiency to a range where the reduction efficiency is high and removing a non-ferrous metal ion contained therein to obtain a purified solution. The reduction reaction of ions is not hindered, and the reduction efficiency of non-ferrous metal ions is improved as a whole. In this way, after the non-metal ions are removed and a part or all of the remaining part of the etching waste liquid is mixed with the purified liquid enriched with ferrous ions,
Since the method includes the third step of injecting chlorine gas to obtain an etching solution enriched in ferric ions in the solution, a predetermined level of etching ability can be added to the etching solution. Furthermore, since the amounts of the purified liquid and the etching waste liquid mixed in the third step are controlled to adjust the non-ferrous metal ion concentration of the etching liquid and produce an etching liquid having a reaction rate adapted to the etching target, When performing an etching process using this etchant, non-metal ions are interposed to prevent the etching rate from becoming excessive, thereby causing irregularities on the etched surface of the object to be etched and variations in dimensional accuracy. This can effectively suppress the occurrence of processing defects due to the above. At the same time, the etching rate can be kept within a range where a practical etching process can be performed, and the processing quality can be maintained satisfactorily.

In the method for treating an etching waste liquid according to claim 2, since the pH value of the hydrogen ion concentration exponent pH of the treatment liquid to be treated in the second step is in a specific range, the amount of elution of iron powder and the treatment in the second step By adjusting the amount of liquid, the production efficiency of the finally obtained purified liquid can be maintained in an appropriate range. In the method for treating an etching waste liquid according to the third aspect, the non-ferrous metal contains nickel, and the nickel ion concentration of the etching liquid is set to a specific range. Non-ferrous metal ions are interposed in the metal layer to prevent the etching rate from increasing and causing scouring on the processed surface, thereby suppressing the occurrence of processing defects and improving the efficiency of etching processing. In the method for treating an etching waste liquid according to claim 4, since the non-ferrous metal contains copper and the copper ion concentration of the etching liquid is adjusted to a specific range, the etching for etching the lead frame for semiconductor containing copper is performed. Efficiency can be maintained in a range where machining defects are reduced. In the method for treating an etching waste liquid according to claim 5, the treatment of the etching waste liquid is performed in a waste liquid treatment facility located on or near the site of the etching factory, and the etching waste liquid disposed in the etching factory is removed. Since the waste liquid tank to be stored and the waste liquid processing equipment are connected by using pipes, it is possible to economically transport the etching waste liquid and the etching liquid regenerated by the waste liquid processing equipment without using a transportation means such as a tank truck. Can be. In the method for treating an etching waste liquid according to claim 6, the etching waste liquid is supplied to the waste liquid processing equipment via a pipe by using a head difference between the waste liquid tank and the waste liquid processing equipment or a pumping means using a pump. Thus, the processing of the etching waste liquid can be performed more efficiently.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an etching facility to which an etching waste liquid treatment method according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory view of an iron powder stirring tank in the etching equipment.

FIG. 3 is an explanatory view of a fluidized bed tank in the etching equipment.

FIG. 4 is an explanatory diagram schematically showing a relationship between an etching rate and a nickel ion concentration in an etching solution.

FIG. 5 is an explanatory view showing a modified example of a device applied to a reduction device and a nickel removal device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Etching equipment 11 Etching factory 12 Piping 13 Waste liquid treatment equipment 14 Etching equipment 15 Waste liquid tank 16 Mixing tank 17 Chlorine gas blowing equipment 18 Filtration equipment 19 Reduction equipment 20 Nickel removal equipment 21 Purification equipment 22 Iron powder stirring tank 23 Container 24 Stirring blade 25 Sensor 25a Sensor 26 Fluidized bed tank 27 First partitioned section 28 Second partitioned section 29 Third partitioned section 30 Fourth partitioned section 31 Fifth partitioned section 32 Pump 33 Circulation pipe 40 Fluidized bed stirring tank 41 First partitioned section 42 First 2 partitioning section 43 3rd partitioning section 44 Fluid medium supply section 46 Partition board 47 Supply port 48 Supply port 49 Nozzle 50 Outlet 51 Treatment liquid discharge port 52 Pump 53 Circulating liquid supply port

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D050 AA13 AB55 AB56 AB57 BA02 BB05 BD03 BD06 BD08 CA13 CA15 4K057 WH02 WH08 WH10 WM19 WN01 WN03

Claims (6)

[Claims] 1. An etching waste liquid containing non-ferrous metal ions, first and second iron ions and discharged from an etching factory is partially taken out, iron powder is added, and the oxidation-reduction potential ORP is adjusted to -350 to +100 mV. A first step of reducing the contained ferric ions to ferrous ions, and further contacting the treatment liquid obtained in the first step with iron powder to have an oxidation-reduction potential ORP of -550 to -350 mV. Adjusting to the range, a second step of obtaining a purified solution by removing non-ferrous metal ions contained therein, and after mixing a part or all of the remaining part of the etching waste liquid with the purified solution, blowing chlorine gas into the solution And a third step of obtaining an etchant enriched in ferric ions, wherein the amount of the etching waste liquid added to the purified liquid mixed in the third step is controlled to control the amount of non-ferrous metal in the etchant. I A method for treating an etching waste liquid, comprising adjusting an on-concentration and producing the etching liquid having a reaction rate adapted to an etching target. 2. The method for treating an etching waste liquid according to claim 1, wherein the pH of the treatment liquid treated in the second step is in the range of 1.5 to 3.0. . 3. The method for treating an etching waste liquid according to claim 1, wherein the non-ferrous metal contains nickel, and the etching liquid has a nickel ion concentration of 10 to 25 g / cm 2.
Etching waste liquid treatment method in the liter range. 4. The method for treating an etching waste liquid according to claim 1, wherein the non-ferrous metal contains copper, and the etching liquid has a copper ion concentration of 5 to 100 g.
/ Liter treatment method for etching waste liquid. 5. The method for treating an etching waste liquid according to claim 1, wherein the processing of the etching waste liquid is performed in a site where an etching process is performed or in a location adjacent to the site. A method for treating an etching waste liquid, which is performed in a facility, and wherein the waste liquid tank in the site where the etching process is performed and the waste liquid treatment equipment are connected by using a pipe. 6. The method for treating an etching waste liquid according to claim 5, wherein the etching waste liquid is connected to the waste liquid processing equipment by using a head difference between the waste liquid tank and the waste liquid processing equipment or a pumping means using a pump. For treating the etching waste liquid supplied through the air.