JPH1112768A - Method for regenerating waste iron chloride-base liquid etchant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for regenerating a waste iron chloride-base liq. etchant by which a large amt. of the waste etchant is efficiently reduced by the use of iron powder with a less power. SOLUTION: A waste iron chloride-base liq. etchant 11 contg. impurity metal ions of the copper, nickel, etc., lower in ionization tendency than iron is mixed with iron powder to cause a reaction between the iron powder and metal ions, and the impurity metal ions are removed. The waste etchant 11 or a waste iron chloride-base liq. 17 as the intermediate treated liq. is supplied from the bottom of an agitated tank 18 retaining iron powder, an iron powder-treated liq. 19 flowing out from the upper part of the tank 18 is drawn off and recycled to the bottom of the tank 18 to form a fluidized bed, and the iron powder- treated liq. 19 freed from the ions of the metals lower in ionization tendency than iron is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal ion having a lower ionization tendency than iron (e.g., from iron chloride-based etching waste liquid generated when etching lead frames for ICs and LSIs and shadow masks for cathode ray tubes).
The present invention relates to a method for regenerating an iron chloride-based etching waste liquid which can be suitably applied to a case where copper (nickel) and nickel (Ni) are removed and regenerated as an etching solution.

[0002]

2. Description of the Related Art Conventionally, for lead frames and shadow masks for ICs and LSIs, for example, plate-like materials made of copper, iron-nickel alloy, or the like have been used, and these plate-like materials include ferric chloride. It is manufactured by partially corroding with an etching solution containing a large amount. Since the ferric chloride contained in the etchant is reduced by the etching process to become ferrous chloride, and the concentration of ferric chloride decreases, the etching efficiency deteriorates. Therefore, the etchant is periodically replaced. ing. In addition to high-concentration iron ions, valuable copper ions,
Contains a considerable amount of nickel ions. Further, if these metal ions are removed from the etching waste liquid, an etching liquid that can be reused can be obtained. Therefore,
For example, in Japanese Patent Application Laid-Open No. 1-167235, iron dust or iron powder is added to an etching waste liquid to reduce metal ions (for example, copper ions and nickel ions) having a smaller ionization tendency than iron in the etching waste liquid. In addition, there has been proposed a method of recovering copper and nickel in a waste liquid and regenerating an etching liquid. However, the method described in this publication has a problem that the quality of the recovered copper or nickel is low, and further, when the reaction is performed using scrap iron, the reaction rate with the etching waste liquid is low. Therefore, Japanese Patent Application Laid-Open
JP-127946 discloses that iron powder is added to an iron chloride-based strong acid waste liquid containing copper, nickel and a small amount of chromium to control an oxidation-reduction potential (ORP) and an iron ion concentration to dissolve dissolved copper. And nickel ions are sequentially substituted and precipitated,
A method for regenerating an iron chloride-based etching waste liquid that separates and removes suspending impurities such as ferric hydroxide from the purified iron chloride solution thus produced has been proposed.

[0003]

However, in the method described in JP-A-6-127946, the operation of reducing and removing metal ions is performed by providing a stirring blade in a stirring tank.
Since the stirring blades are rotated by a motor to perform stirring, there are the following problems (1) to (5). When treating the etching waste liquid, it is indispensable to maintain the etching waste liquid in the stirring tank in a good fluidized state and to hold a large amount of iron powder in a dispersed state. In a mechanically stirred reaction tank, there is a facility limit (for example, a large motor that rotates a large stirring blade becomes very expensive) in order to keep the iron powder dispersed in the etching waste liquid. It is not suitable for etching waste liquid treatment. In order to disperse a large amount and uniformity of iron powder having a large specific gravity in the etching waste liquid, and to maintain the suspended fluid state, a large power is required to drive the stirring blades, thereby increasing the operating cost. Since the iron powder is agitated at high speed by the stirring blade, the iron powder comes into contact with the inner wall of the stirring tank and the stirring blade, and the amount of wear of each of the iron powder and the maintenance cost of the stirring tank increases. Iron powder stays in the corners of the stirring tank and creates a dead space in which the iron powder and the etching waste liquid cannot be sufficiently stirred, which lowers the stirring efficiency and removes metal ions having a smaller ionization tendency than iron in the etching waste liquid. The processing time required for removal increases. It is known that in a stirring tank that performs forced stirring using stirring blades, it is possible to relatively easily maintain a good suspended fluid state by using iron powder having a small particle size. The raw material cost of special size iron powder increases.

[0004] In addition, when an etching waste solution is put into a stirring tank and iron metal is used to reduce and remove impurity metals,
If ferric chloride ion is present, a reduction reaction of ferric chloride ion occurs first, and iron powder is consumed, thereby eventually increasing the total amount of ferrous and ferric ions in the etching waste liquid. Since it is necessary to finally dilute in order to obtain an etchant of a predetermined concentration that can be used, an excessive amount of etchant is generated more than necessary, and the storage equipment becomes larger,
If not all of the resulting etchant is used, there is a problem with the processing of the excess etchant that is not used. On the other hand, as a method for producing iron powder which can be used in the above-described method for treating an etching waste liquid, for example, Japanese Patent Publication No.
There is a method described in JP-A-44724, which comprises the following four steps. That is, in the first step, dust generated in a pure oxygen blowing steelmaking converter is collected by a wet method, and the dust is classified to reduce particles having a size of 44 μm or less to 30% or less. Then, impurities such as scale and slag are separated from the coarse-grained dust by a wet-type fine pulverizer, and in a third step, impurities are removed from the separated dust to obtain metallic iron. Iron powder is extracted by purifying iron. However, in the method for producing iron powder described in Japanese Patent Publication No. 57-44724, the step of removing impurities from dust to obtain iron powder is performed by classification, thin-stream separation, or magnetic separation, so that the dust processing capacity is reduced. And there is a problem that mass processing is difficult. Further, in the step of refining metallic iron, processing is performed in combination with refining treatment by iron oxide refining or dilute acid leaching. The present invention has been made in view of such circumstances,
It is possible to efficiently reduce a large amount of etching waste liquid with less power by using iron powder, and furthermore, it is possible to reduce metal ions such as copper and nickel in iron chloride-based etching waste liquid that have a lower ionization tendency than iron. It is an object of the present invention to provide a method for regenerating an iron chloride-based etching waste liquid capable of reducing and recovering (hereinafter sometimes referred to as “impurity metal ions”). In addition, iron powder is put into the etching waste liquid to reduce and recover metals such as copper and nickel, and a surplus amount of the etching liquid that is eventually generated when the ferric ion is brought to a predetermined concentration is reduced. Another object of the present invention is to provide a method for regenerating an iron chloride-based etching waste liquid that can reduce the cost and the production cost associated therewith.

[0005]

According to the present invention, there is provided a method for regenerating an iron chloride-based etching waste liquid according to the present invention, wherein the iron chloride-based waste liquid contains metal ions, such as copper and nickel, having a smaller ionization tendency than iron in a stirring tank. In the method for regenerating an iron chloride-based etching waste liquid in which iron powder is mixed, and the iron powder reacts with the metal ions to precipitate and remove the metal ions, and then oxidize the iron powder treatment liquid, While supplying the iron chloride waste liquid to the tank, taking out the iron powder treatment liquid after reacting the iron powder from the top of the stirring tank, and circulating the iron powder treatment liquid to the bottom of the stirring tank to supply the iron powder. Forms a fluidized bed in which the iron powder is dispersed and suspended, and the excess iron powder treatment liquid is taken out from the upper part of the stirring tank. In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, a fluidized bed is formed by taking out an iron powder treatment liquid from which impurity metal ions have been removed from the top of a stirring tank and circulating and supplying it to the bottom of the stirring tank. Therefore, the fluidized medium necessary for maintaining the state of the fluidized bed in an appropriate range can be covered only by the iron powder treatment liquid. Therefore, even when the supplied iron chloride waste liquid fluctuates, a fluidized bed can be formed stably, and as a result, the reaction between the iron chloride waste liquid and the iron powder can be performed in a stable state. Furthermore, since a part of the iron powder treatment liquid is taken out from the top of the stirring tank and supplied from the bottom, a fluidized bed can be formed without creating a dead space in the stirring tank that does not contribute to the reaction. And the efficiency of removing impurity metal ions in the supplied iron chloride waste liquid can be increased.

In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, it is preferable that the iron chloride-based waste liquid be supplied from the bottom of the stirring tank so as to promote the formation of the fluidized bed. In addition, the treatment rate can be increased by increasing the degree of contact between the iron chloride waste liquid and the iron powder. Further, in the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the flow rate of the ascending liquid is reduced by increasing the diameter of the upper part of the agitating tank from the fluidized bed forming part in which the fluidized bed is formed. It is preferable to provide an iron powder separating unit for suppressing the rise of iron powder. As a result, when the upward flow of the fluid in the stirring tank is decelerated in the iron powder separation unit, the iron powder having a predetermined particle size or more does not float and move to the iron powder separation unit, and the flow rate in the stirring tank slightly fluctuates. However, the upper end of the fluidized bed can be held at a fixed position, and impurity metal ions can be removed under stable conditions. In the method for regenerating an iron chloride-based etching waste liquid according to the invention described above, the iron chloride-based waste liquid supplied to the stirring tank is a part of or almost all of the ferric ion obtained by previously subjecting the iron chloride-based etching waste liquid to an electrolytic treatment. It is preferable to use an aqueous solution of reduced iron chloride reduced to ferrous ions, for the following reasons. Even if ferric ion is reduced to ferrous ion by electrolysis treatment of the iron chloride etching waste liquid as described above, the total iron ion concentration of ferrous ion and ferric ion does not change. Become. Therefore, in the final step, the amount of iron does not change during the regenerating treatment of the iron chloride-based waste liquid by oxidizing ferrous ions (for example, by blowing chlorine gas) into ferric ions. Therefore, the concentration of the etching solution is not excessively increased. That is, when the treatment is performed using only iron powder as in the conventional case, the contained ferric ion reacts with the iron powder to form a ferrous ion, and as a result, the amount of iron contained is more than necessary. Increase to
When the ferrous ion is oxidized in the final step, an excess liquid is generated. However, in the present invention, since the ferric ion is reduced to the ferrous ion without using the iron powder, In addition, the generation of surplus liquid can be prevented as much as possible, whereby the cost for processing the surplus liquid can be reduced, and the processing equipment can be made compact. Further, since the amount of iron powder used in the regeneration treatment of the iron chloride waste liquid can be reduced, the treatment cost can be reduced.

Here, the average electrolysis voltage of the iron chloride-based etching waste liquid in the electrolysis treatment is 1 to 4.5 V.
(More preferably, 1.5 to 3 V), and the current density is 2 to 4
0 A / dm ² (more preferably, 3 to 20 A / dm ² )
It is preferable to control within the range. This controls the electrolysis voltage and current density in the electrolysis process to a specific range, so that the necessary reduction effect is maintained without depositing impurity metal ions such as copper and nickel contained in the iron chloride waste liquid, Further, it is possible to more efficiently regenerate the iron chloride waste liquid. If the electrolysis voltage is lower than 1 V, the electrolysis voltage is substantially lower than the theoretical electrolysis voltage for reducing ferric ions to ferrous ions, and a reduction effect cannot be obtained. Conversely, if the electrolysis voltage exceeds 4.5 V, impurity metal ions such as copper and nickel contained in the iron chloride-based etching waste liquid are undesirably precipitated. Further, when the current density is lower than 2 A / dm ^2, the treatment capacity of the iron chloride waste liquid is reduced. Therefore, in order to treat a predetermined amount of liquid, the equipment needs to be upsized. When the current density exceeds 40 A / dm ² , the electrolysis voltage increases and the power cost increases, which is uneconomical. Further, the load on the electrode is increased, which shortens the life of the electrode and promotes precipitation of impurity metal ions, which is not preferable. Further, it is preferable that the distance between the anode plate and the cathode plate of the electrolysis tank in the electrolysis treatment is 1.5 to 50 mm. With this configuration,
Since the distance between the anode plate and the cathode plate in the electrolysis tank is in a specific range, the invasion of chlorine gas generated in the anode plate into the cathode portion can be suppressed, and oxidation of ferrous ions can be suppressed, An increase in the electrolytic voltage can be suppressed. Here, if the distance between the electrodes is shorter than 1.5 mm, chlorine gas generated in the anode plate easily penetrates the diaphragm and enters the cathode portion, where ferrous ions are oxidized (FeCl ₂ + (1/1)
2) Cl ₂ → FeCl ₃ ). In addition, since it becomes substantially difficult to supply the liquid to the electrode surface, metals such as copper and nickel are easily deposited. In addition, the distance between the poles is 5
Exceeding 0 mm is not preferable because the electrolytic voltage increases and the power cost rises. A more desirable distance between the poles is 2 to
The range is 20 mm.

The electrolysis tank for performing the electrolysis treatment is divided into an anode chamber having an anode by a liquid-permeable membrane and a cathode chamber having a cathode. The reduced iron chloride aqueous solution supplied from a part of the cathode chamber and passed through the cathode chamber and subjected to reduction treatment can be taken out from the other part of the cathode chamber. Thereby, the chlorine gas generated in the anode plate can be substantially prevented from being mixed with the supplied iron chloride-based etching waste liquid or the aqueous solution of reduced iron chloride, and efficient electrolysis can be performed. The concentration of the remaining ferric ion in the reduced aqueous solution of iron chloride treated by the above electrolysis treatment is set to 1
It is preferably from 0 to 120 g / liter. The reason for this is that the concentration of ferric ion in the reduced aqueous iron chloride solution is 10 g.
/ Liter, the amount of ferric ion reduced to ferrous ion per unit current decreases, and
Further, the contained copper ions and nickel ions are precipitated to produce copper and nickel, which is not preferable. If the concentration of ferric ion in the reduced iron chloride aqueous solution exceeds 120 g / liter, the ferric ion reacts with the iron powder in the stirring tank, so that the consumption of the iron powder increases. Excess etching solution increases. From the above, the concentration of ferric ion in the reduced aqueous solution of iron chloride is set in the range of 10 to 120 g / liter, and more preferably 100 g / liter.
g / liter or less. Here, part or all of the chlorine gas generated from the anode in the electrolysis treatment is blown into the iron powder treatment liquid taken out of the stirring tank, and a part of ferrous ions is oxidized to form ferric iron. Preferably, it is an ion. Thereby, the regeneration treatment of the iron chloride-based etching waste liquid can be efficiently performed without generating unnecessary by-products.

The iron powder used in the present invention is recovered by a wet method from dust containing impurities such as CaO generated from a steelmaking furnace, and the iron powder dust is crushed and washed with water to remove the impurities. It is preferable to use purified iron powder that has been removed and further washed with acid. Thereby, the iron powder generated from the steelmaking furnace can be effectively used, and further, impurities such as CaO can be reduced in the regenerated etching solution. The pickling of the iron powder dust may be performed in a process in which the iron powder dust is gradually discharged by a screw conveyor provided with an acid liquid inlet at an inclined position in a settling tank for storing the iron powder dust. Thus, the iron powder used for the reduction treatment of the iron chloride waste liquid can be produced in large quantities at low cost by continuous treatment. Here, the hydrogen ion concentration of the pickling solution in the precipitation tank is preferably adjusted to pH 0.5 to 3. As a result, the amount of impurities such as CaO in the purified iron powder can be maintained at a predetermined level, and the acid solution cost, the treatment cost, and the equipment maintenance cost can be controlled within an appropriate range, and the chloride cost can be further reduced. Regeneration treatment of iron-based waste liquid can be performed. If the hydrogen ion concentration (pH) of the acid solution is smaller than 0.5, the acid solution becomes highly corrosive, and it is necessary to perform a special acid-resistant treatment on the equipment, thereby increasing the equipment maintenance cost. On the other hand, when the hydrogen ion concentration is more than 3, it is not preferable because impurities including scale, slag, and the like that adhere to the iron powder cannot be sufficiently eluted.

In the above-described method for regenerating an iron chloride-based etching waste liquid according to the present invention, the iron chloride-based waste liquid includes ferrous chloride (FeCl ₂ ) and ferric chloride (FeCl ₂ ).
_This refers to an acidic aqueous solution such as an etching waste liquid containing ₃ ), and contains metal ions such as copper, nickel, and chromium which have a smaller ionization tendency than iron in the etching process. The iron powder is, for example, powdered iron having a particle diameter of 44 to 250 μm, and includes a spherical shape, a porous shape, and the like, but is not limited thereto. Applicable to manufactured iron powder, iron powder obtained by grinding iron, and the like. The fluidized bed is a region where the iron powder supplied into the stirring tank is balanced by its own gravity and viscous resistance by the flow supplied from the lower part, and has a high density of iron powder floating and flowing in a certain space. . The iron powder treatment liquid is mainly an aqueous solution from which metal ions of impurities such as copper and nickel that have passed through the fluidized bed and springed out are reduced and removed, and iron powder and solid suspended solids not separated in the liquid In a small amount, for example, 20 w
It is defined including the case of containing about t% or less. The iron powder separating unit refers to a region located above a fluidized bed partitioned so as to divide the stirring tank in the vertical direction, but is not physically separated from each other. Since the horizontal cross-sectional area of the iron powder separating section is expanding upward, the flow rate of the iron chloride aqueous solution supplied from the lower part of the stirring tank is reduced, and the floating and flowing iron powder enters the iron powder separating section and rises. Work in the fluidized bed without the need to do so.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, with reference to the attached drawings, embodiments of the present invention will be described to provide an understanding of the present invention. Here, FIG. 1 is a conceptual configuration explanatory view of a waste liquid treatment facility to which a method of regenerating an iron chloride etching waste liquid according to a first embodiment of the present invention is applied, and FIG. 2 is a description of an electrolysis apparatus of the waste liquid treatment facility. FIGS. 3 to 7 are schematic diagrams showing a plurality of patterns of the arrangement of the supply position of the iron chloride-based etching waste liquid and the extraction position of the reduced aqueous solution of iron chloride in the electrolysis apparatus, respectively, and FIG. FIG. 9 is a side sectional view of a water washing device and an acid pickling device in the iron powder refining facility, FIG. 10 is a cross-sectional view taken along line II of FIG. 9, and FIG. FIG. 12 is an explanatory view of a stirring tank of the waste liquid treatment facility, and FIGS. 13 (a), (b), and (c) respectively show an electrolytic voltage, a current density, and an electrolysis device. 14 (a), (b), a time transition diagram of the ferric ion concentration, c), (d) the transition schematic of the ion concentration in the regeneration process of the iron waste chloride, 15 transition diagram of CaO concentrations of iron dust, FIG. 16
Is an explanatory view of an etching waste liquid treatment equipment to which a method for regenerating an iron chloride etching waste liquid according to a second embodiment of the present invention is applied, FIG. 17 is a cross-sectional view of a second stirring tank used in the equipment,
FIG. 18 is a side sectional view showing another example of the second stirring tank, and FIG.
FIG. 19 is a view taken along the line II-II in FIG. 18.

(First Embodiment) First, the configuration of a waste liquid treatment facility 10 to which a method for regenerating an iron chloride etching waste liquid according to a first embodiment of the present invention is applied will be described with reference to FIGS. explain. As shown in FIG.
Is an electrolysis apparatus 1 for reducing ferric ions in ferric chloride-based etching waste liquid 11 to ferrous ions.
2, an iron powder refining facility 16 for refining iron powder dust 14 taken out of a converter 13 which is an example of a steelmaking furnace to obtain a purified iron powder 15, a reduced iron chloride aqueous solution 17 treated in the electrolyzer 12, and A stirring tank 18 for stirring the purified iron powder 15 obtained by the iron powder refining equipment 16 to precipitate impurity metals from the reduced iron chloride aqueous solution 17, and ferrous iron in the iron powder treatment liquid 19 taken out from the stirring tank 18. A chlorination apparatus 21 for oxidizing the ions to obtain an etching solution 20 regenerated as ferric ions. Hereinafter, the configuration of each device of the waste liquid treatment facility 10 having the above configuration will be described. First, the specific configuration of the electrolyzer 12 will be specifically described with reference to FIGS. As shown in FIG. 2, in the electrolyzer 12, an anode plate (anode) 23 and a cathode plate (cathode) 24 are held at predetermined intervals, a liquid inlet 25 for the iron chloride-based etching waste liquid 11 is provided at a lower part, and a treatment port is provided at an upper part. An electrolysis tank 27 having a liquid outlet 26 for the reduced aqueous solution of reduced iron chloride 17, a DC power supply 28 for applying an electrolytic voltage to the anode plate 23 and the cathode plate 24, and an electrolysis tank 27.
, Current density (D), the concentration of ferric ion (C) in the reduced iron chloride aqueous solution 17, the amount of chlorine gas generated from the anode plate 23, etc., are inputted, and the electrolytic voltage (E) and the iron chloride etching waste liquid are input. 11 has a control unit 29 for controlling the supply flow rate (Q) and the like.

The electrolysis tank 27 is partitioned into an anode chamber 31 and a cathode chamber 32 by a diaphragm 30 disposed around the anode plate 23, and chlorine gas generated from the anode plate 23 is provided above the anode chamber 31. Gas outlet 33 for trapping air
Is provided. In the present embodiment, as shown in FIG. 2, the supply position of the iron chloride-based etching waste liquid 11 to the electrolysis tank 27 and the extraction position of the reduced iron chloride aqueous solution 17 treated in the electrolysis tank 27 are, as shown in FIG. By providing a liquid inlet 25 for the etching waste liquid 11 and a liquid outlet 26 for the reduced iron chloride aqueous solution 17 on the side of the cathode chamber 32, a pattern of cathode side supply and cathode side extraction was adopted. By doing so, the supplied iron chloride-based etching waste liquid 11
The ferrous ions in the treated reduced iron chloride aqueous solution 17 are less likely to be oxidized by chlorine gas generated in the anode plate 23, and the ferrous ions in the iron chloride-based etching waste liquid 11 are located near the surface of the cathode plate 24. Ferrous ions can be supplied promptly. However, the arrangement of the liquid inlet 25 for the iron chloride-based etching waste liquid 11 and the liquid outlet 26 for the reduced iron chloride aqueous solution 17 may be the electrolysis tanks 34 to 37 and 37a having the patterns shown in FIGS. . Further, in the electrolysis tanks 34 to 37 and 37a of each pattern, the formation positions of the liquid inlet 25 of the iron chloride-based etching waste liquid 11 and the liquid outlet 26 of the reduced iron chloride aqueous solution 17 can be exchanged as needed. The electrolysis tank 2 shown in FIGS.
7, 34-37, 37a, a pair of anode plates 23
Although an example composed of a combination of a cathode plate 24 and a cathode plate 24 is conceptually shown, it is actually a structure in which a plurality of portions where an anode chamber and a cathode chamber are separated by a diaphragm are arranged. In addition,
In FIG. 7, the anode plate 23 is completely partitioned by the diaphragm 30, and the chlorine gas is discharged from the upper part. In addition, the present invention is not limited to the examples of FIGS. 2 to 7 and the electrolysis tank is not limited thereto. For example, there are a well-known filter press system and a bath system. There are a pole method and a bipole method.

As the anode plate 23, for example, a DSE electrode or a DSA electrode made of Permec Co., which is obtained by partially covering ruthenium oxide on titanium, is preferably used. Although a platinum-coated titanium or graphite plate or the like can be used for the anode plate 23 as the electrode, it is preferable to use a DSE electrode having a low chlorine overvoltage, a high oxygen overvoltage and a low electric resistance. As a material of the cathode plate 24, graphite, titanium, iron,
Stainless steel, copper, nickel, a nickel alloy, or the like can be used, and it is desirable to use titanium or a nickel alloy having a high hydrogen overvoltage and a small electric resistance. The shape of the anode plate 23 and the shape of the cathode plate 24 may be a net-like shape obtained by drawing a metal plate having a large number of small cuts, such as a so-called expanded metal, a bar, a plate, or a blind. . In FIG. 2, a diaphragm 30 blocks chlorine gas generated in the anode plate 23 from the cathode chamber 32 and
Oxidation reaction of ferrous chloride (FeCl ₂ + (1 /
2) It has a function of preventing Cl ₂ → FeCl ₃ ) and collecting chlorine gas. The material of the diaphragm 30 is preferably a material that has liquid permeability but has good shielding of generated chlorine gas and is inexpensive. Specifically, a filter cloth and an ion exchange resin are suitable, and in this case, a filter cloth made by Izumi Co., Ltd. having a thickness of about 1 mm (trade name "Pyren Filament PF4000")
It was used.

The distance L between the anode plate 23 and the cathode plate 24 is set to 8 mm in this embodiment. However, if necessary, the distance L between the electrodes, that is, the gap between the electrodes is set to 1.5 mm.
It is also possible to change it in the range of 〜50 mm, and it is desirable to set the distance L between the electrodes in the range of 2 to 20 mm. The control unit 29 is, for example, a control device including a program controller (sequencer) or the like that preliminarily inputs a predetermined processing program and performs processing according to the input program. Control operations such as Q, electrolysis voltage E and the like can also be performed. The function of the control unit 29 will be described. The current i supplied to the electrolytic cell 27 can be measured by an ammeter 38 provided between the DC power supply unit 28 and the electrolytic cell 27. The anode plate 23 and the cathode plate 24
Of the current density D (= i / S). In addition, the metal ion concentration (ferric ion concentration) C in the reduced iron chloride aqueous solution 17 taken out from the electrolysis tank 27 can be measured continuously or intermittently with an ion meter or the like as necessary. Then, the control unit 29
In the above, control data of the current density D and the ferric ion concentration C are input, and the electrolytic voltage E and the supply flow rate Q of the iron chloride-based etching waste liquid 11 can be adjusted based on the control data. Has become. Next, converter 1
The iron powder refining equipment 16 that can produce the refined iron powder 15 by refining the iron powder dust 14 taken out from 3 will be specifically described with reference to FIGS.

As shown in FIG. 8, the iron powder refining facility 16 comprises:
The raw material feeder 40 of the iron dust 14, the primary grinding ball mill 41, the pre-cleaning Akins 42, the secondary grinding vibratory mill 43, the water cleaning device 44, the pickling device 45, the secondary cleaning Akins 46, It has a dryer 47 and a vibrating sieve 48, and the refined iron powder 15 is manufactured by arranging these devices in series. In addition, since the structure of the above-mentioned apparatus except the water washing apparatus 44 and the pickling apparatus 45 is well-known, detailed description is omitted. Hereinafter, the configurations of the water washing device 44 and the pickling device 45 that are the main parts of the iron powder refining facility 16 will be described with reference to FIGS. 9 and 10. As shown in FIG.
An inverted conical first sedimentation tank 49 into which the treated material is charged;
And a screw conveyor 50 for washing and discharging the precipitate in the first settling tank 49. On the other hand, the pickling device 45
A second settling tank 51 having an inverted conical shape into which washing iron powder discharged from the upper portion of the screw conveyor 50 of the washing device 44 is charged, and scooping up the precipitate in the second settling tank 51 for washing; A screw conveyor 52 for performing classification and water removal. The screw conveyors 50 and 52 are
The respective lower parts are a first settling tank 49 and a second settling tank 51.
The screw conveyors 50 and 5 are inclined at an angle of 10 to 50 degrees with respect to the horizontal direction.
At least the upper part of 2 has an open trough structure. The screw conveyors 50 and 52 are provided with spiral bodies (screws) 53 and 54 for scraping up and moving the sediment deposited on the bottoms of the first and second sedimentation tanks 49 and 51, respectively. ing. Spiral 5
By rotating the motors 3 and 54 by a motor (not shown), the sediment accumulated at the bottoms of the first and second sedimentation tanks 49 and 51 is gradually conveyed to the upper part by the screw conveyors 50 and 52. I have.

Each of the screw conveyors 5
A water supply pipe 55 and an acid solution supply pipe 56 are provided above the spiral bodies 53 and 54 of 0 and 52, respectively. The water supply pipe 55 is provided with a water discharge port 57, and the acid solution supply pipe 56 is provided with an acid solution injection port 58. Washing water and pickling solution are supplied to the open portions of the screw conveyors 50 and 52, respectively. It can be supplied. Therefore, the sediment that moves upward by the rotation of the spiral bodies 53 and 54 in the screw conveyors 50 and 52, respectively,
The washing water and the pickling liquid flowing down by gravity in the inside 2 are effectively stirred and mixed, so that relatively small particles in the precipitate are washed away and the screw conveyor 5 is washed.
The sediment, which descends in the inside of the first and second sedimentation tanks 49 and 51 by moving down the inside of the first and second sedimentation tanks 49 and 51 and has the fine powder portion removed, is provided at the upper part of the screw conveyors 50 and 52 with a discharge port 59 facing downward. , 59a. The pre-cleaning Akins 42 and the secondary cleaning Akins 46 also have screw conveyors, respectively, and have the same structure as the above-described water washing device. In addition, collection of the iron powder dust 14 supplied from the converter 13 to the iron powder refining facility 16 is as follows.
For example, it can be performed by the iron powder collecting equipment 60 shown in FIG. That is, as shown in FIG.
A hood portion 61 for collecting dust and generated gas generated from the converter 13 is provided, and a starting end of an exhaust system 62 is connected to the hood portion 61. A chimney 63 for discharging gas detoxified by a dust collecting operation described later into the atmosphere is connected. A first water outlet 67 and a first trapped dust outlet 6 are provided at the upper and lower ends of the first straight pipe portion 62a, which is the upstream side of the exhaust system 62, respectively.
7a. Water is injected from the first water jet port 67 into the first straight pipe portion 62a to come into contact with the generated gas flowing in the exhaust system 62, and the dust including iron powder in the generated gas is almost (95% ) Capture. Then, the captured dust is fed to the wet classifier 64 to be described later through the first captured dust discharge port 67a in a state of being mixed with the injection water.

As shown in FIG. 11, the first straight pipe portion 6
A second straight pipe portion 62b is provided downstream of 2a via a horizontal step portion, and a second water ejection port 65 and a second trapped dust discharge port 65a are provided at an upper end and a lower portion, respectively. ing. Water is supplied from the second water jet port 65 to the second straight pipe portion 62b.
The exhaust gas flows into the exhaust system 62 and is brought into contact with the generated gas flowing through the exhaust system 62, so that the remaining dust (5%) contained in the generated gas can be almost captured. Then, the jet water mixed with the captured dust passes through the second captured dust discharge port 65a,
It is sent to the dust processing tank 66. In addition, since this injection water contains only a small amount of dust, by using the pump P, the first water injection port 67 can be connected to the first straight pipe portion 62.
It can be effectively used as injection water for injection into a. The wet classifier 64 has a dust sedimentation tank 68. As shown in FIG.
Dust containing iron powder discharged from the first straight pipe portion 62a is
Supplied with injection water. Then, only dust containing iron powder is settled as settled dust D at the bottom of the dust settling tank 68. In the dust settling tank 68, there is a long pipe 69a.
And a screw conveyor 70 composed of a spiral body 69 rotating in a pipe 69a, the starting end of which is located in the dust sedimentation tank 68 and the end end projecting above the upper edge of the dust sedimentation tank 68. ing. At the end of the screw conveyor 70, a washing water supply device 70a is provided.

Accordingly, in such a wet classifier 64, by supplying washing water or the like from the end side of the screw conveyor 70, the fine powder portion in the sediment selectively descends along the inner wall of the screw conveyor 70. The precipitate (iron powder dust) which has flowed out and has a relatively large particle size in the precipitate and from which excess water has been removed can be taken out from the upper portion of the screw conveyor 70. In this embodiment, the thickener 6 provided with the supernatant liquid in the upper part of the dust settling tank 68 is arranged in parallel.
4a to precipitate and remove fine components (iron oxide, etc.) in the supernatant liquid to produce clean water, and to inject this clean water from the second water outlet 65 into the second straight pipe portion 62b. It is used as water. Thus, the cost required for the iron powder sampling operation can be reduced by the circulating use of water. In the above-described iron powder collecting facility 60,
The first water jet 67 and the second water jet 65 of the exhaust system 62 have a structure in which the tips are narrowed. When water is blown in by the throttle structure, mixing of exhaust gas or dust with water is effective. And the dust trapped by the water can be effectively trapped.

Next, referring to FIG. 12, reduced iron chloride aqueous solution 17 and purified iron powder 15 are stirred to reduce reduced iron chloride aqueous solution 1.
The configuration of the stirring tank 18 for precipitating the impurity metal from 7 will be described. As shown in the figure, the stirring tank 18 has a volume of five regions of a first partition 71 to a fifth partition 75 each having a different horizontal sectional area in the vertical direction.
It is a reaction vessel having a diameter of 7 m ³ and a maximum inner diameter of about 3.2 m, and can hold, for example, about 21 tons of purified iron powder 15 for treating an iron chloride waste liquid. The first partition 71, which is the uppermost part of the stirring tank 18, is a region composed of a straight cylindrical part having a maximum horizontal cross-sectional area, and its upper end opening is open to the atmosphere. The refined iron powder 15 can be put into the inside. On the other hand, the second partition 72 following the first partition 71 is a region including a tapered portion whose diameter gradually decreases in the downward direction. An iron powder separating section (free board) is formed by the first and second partition sections 71 and 72, and the flow rate of the upward flow is reduced, and the iron powder separating section (free board) is suspended in the reduced iron chloride aqueous solution 17 from a fluidized bed described later. That is, it is possible to prevent the iron powder in the dispersed and suspended state from rising and entering the iron powder separating section. On the other hand, a lower portion of the second partition 72 is formed with a third partition 73 having a straight section having the same cross-sectional area as the lower end of the second partition 72. Fourth consisting of a tapered part
The partitioning section 74 is provided continuously, and a fifth partitioning section 75 formed of a small-diameter straight cylindrical section is provided continuously at the lower end of the fourth partitioning section 74. 12 shows a fluidized bed with a high iron powder density capable of holding the iron powder in a floating fluid state by the circulating flow mainly composed of the reduced iron chloride aqueous solution 17 in the third to fifth partition parts 73 to 75. It is formed as shown by hatching.

The first partitioning section 71 forming the iron powder separating section
The processing liquid inlet 78 is provided on the side wall of the fifth partition 75 which forms the lower part of the fluidized bed.
Is provided. Then, the processing liquid partial outlet 76,
77 and the processing liquid inlet 78 are connected to each other by a processing liquid circulation pipe 80 having a circulation pump 79 on the way. Therefore, by driving the circulating pump 79, the iron powder content is extremely small or the iron powder content is reduced from the first and second compartments 71, 72 through the processing liquid partial outlets 76, 77, respectively. The iron powder processing liquid 19 which is not contained is taken out, and then the iron powder processing liquid 19 is passed through the processing liquid circulation pipe 80 and the processing liquid inlet 78 to the fifth partition 75.
The self-circulating flow is formed in the stirring tank 18 by flowing into the inside of the stirring tank 18. Further, at the upper end of the processing liquid circulation pipe 80, first and second flow rates of the iron powder processing liquid 19 passing through the processing liquid circulation pipe 80 through the two processing liquid partial outlets 76 and 77 are controlled. Circulating flow control valves 81, 8
2, a supply flow control valve 83 is provided at the lower end of the processing liquid circulation pipe 80. The first of these,
Second circulation flow control valves 81 and 82, supply flow control valve 83
By using the method, the flow rate of the circulating liquid can be easily controlled. Accordingly, the reduced iron chloride supplied to the stirring tank 18 through the supply pipe 85 of the reduced iron chloride aqueous solution 17 (in some cases, an iron chloride-based etching waste liquid) provided with the waste liquid supply valve 84 and the processing liquid inlet 78. Regardless of the supply amount of the aqueous solution 17 (in some cases, iron chloride-based etching waste liquid), the stirring tank 18 is circulated by the circulating flow.
A fluidized bed can be formed while maintaining the fluidized state of the purified iron powder 15 supplied to the appropriate range.

Further, by discharging a part of the iron powder treatment liquid 19 into the fifth partitioning section 75, which is a small-diameter straight cylindrical part in which the iron powder tends to precipitate, the iron powder and the like can be wound up. The generation of a dead space inside 18 is suppressed. The reduced iron chloride aqueous solution 17
(In some cases, iron chloride-based etching waste liquid 11)
The liquid is supplied to the stirring tank 18 via a supply pipe 87 provided with a waste liquid supply valve 86 in a pipe between the supply flow control valve 83 and the circulation pump 79, or via a supply pipe 85 to the first partition 71. It has become. On the side walls of the first partition 71 and the second partition 72 forming the iron powder separating section, processing liquid outlets 88 and 89 are respectively provided in addition to the processing liquid partial outlets 76 and 77 described above. The processing liquid outlet 8
A processing liquid transfer pipe 91 having a pump 90 in the middle is connected to 8 and 89. On the other hand, the outlet side of the processing liquid transfer pipe 91 is connected to the chlorination device 21 in communication. Therefore, the iron powder processing liquid 19 obtained by processing in the stirring tank 18 is sent to the chlorination apparatus 21 and the like through the processing liquid transfer pipe 91 by driving the pump 90. Further, the processing liquid outlets 88 and 89
The flow rate of the iron powder processing liquid 19 discharged from the first processing flow rate control valve 92 provided at an intermediate position of the processing liquid transfer pipe 91 following the processing liquid discharge ports 88 and 89, and the second discharge flow rate It can be adjusted by the control valve 93. As described above, the iron powder treatment liquid 19 is removed from the reaction compartments having different treatment conditions.
Can be selected as necessary, or the iron powder treatment liquids 19 having different characteristics can be taken out from the separate compartments.
By adjusting the iron ion concentration and the like, the waste liquid treatment thereafter can be controlled to an appropriate condition.

When the purified iron powder 15 in the stirring tank 18 runs short, the purified iron powder 15 is supplied from above the stirring tank 18. A discharge pipe 94a provided with a bottom discharge valve 94 for discharging solids and the like precipitated on the bottom is provided at the bottom of the stirring tank 18, from which solids and the like can be extracted. Next, stirring tank 1
The configuration of the chlorination apparatus 21 for oxidizing ferrous ions in the iron powder treatment liquid 19 taken out from the tank 8 to obtain regenerated etching liquid 20 as ferric ions will be described. Although not shown, since the chlorination apparatus 21 needs to hold the highly corrosive iron powder treatment liquid 19 in a stored state, it is preferable to use a reaction vessel made of a highly corrosion-resistant material such as FRP (fiber reinforced plastic). Become. Then, the chlorine gas generated by the electrolyzer 12 or the like is blown or bubbled into the iron powder treatment liquid 19 treated in the stirring tank 18 so that a part of the ferrous ions in the iron powder treatment liquid 19 or Regenerate etching solution 2 by oxidizing all to ferric ions
0 can be obtained. It is to be noted that such a chlorination reaction can be performed, for example, separately in a primary chlorination step and a secondary chlorination step, whereby the reaction efficiency with chlorine can be further increased. Next, the steps of the method for regenerating the iron chloride-based etching waste liquid according to the first embodiment of the present invention using the waste liquid treatment equipment 10 having the above configuration will be described in detail. First, the iron powder dust 14 collected from the converter 13 using the iron powder refining equipment 16 shown in FIGS.
A method for producing purified iron powder 15 by refining is described. As shown in FIGS. 8 to 10, the iron powder dust 14 containing water discharged from the wet classifier 64 in FIG. 11 is charged into the primary grinding ball mill 41 using the raw material feeder 40. The primary grinding ball mill 41 is a substantially cylindrical ball mill capable of treating the iron powder dust 14 continuously supplied by the raw material feeder 40, and the rotation speed of the ball mill is 20 to 36 rpm. The quantity is 3-5 tons.

The supply amount of water containing iron powder dust 14 sent to the primary grinding ball mill 41 is 200 to 10
00 liter / hr (average: 270 liter / hr), and the concentration of the iron dust 14 is 50 to 80 wt% (average: 65 wt%). The residence time or treatment time of the iron powder dust 14 in such a primary grinding ball mill 41 is about 60 to 120 minutes.
Some of the impurities contained in the iron powder dust 14 can be separated from the iron powder. Here, the reason for performing the wet grinding process as described above is that the dust itself collected from the converter 13 is a wet powder containing a large amount of moisture as described above, and if it is to be processed in a dry process, the drying process is performed as a preliminary process. Is necessary, and since the subsequent pickling treatment itself is performed by a wet method, a drying treatment is required again after the pickling treatment, which is uneconomical. Further, if the pulverization is performed in a dry manner, dust is likely to be generated, and it is necessary to take countermeasures against the dust. Next, the processed material of the iron dust 14 discharged from the primary grinding ball mill 41 is subjected to a wet classifier 64 shown in FIG.
The pre-cleaning akins 42 having the same configuration as that described above is used to wash out the impurities separated from the iron powder. Here, the velocity of the fluid which rises in the settling tank of the pre-cleaning Akins 42 and overflows is 3 to 10 m / hr (average:
5 m / hr), and the supply amount of washing water supplied to the open upper part of the screw conveyor is ³ to 25 m ³ / hr.
(Average: 5 m ³ / hr). The cleaning treatment using the pre-cleaning akins 42 further separates and removes some of the impurities peeled off from the iron powder in the processed material, and simultaneously removes a minute portion from the iron powder. The distribution can be shifted in the direction of increasing particle size.

Next, the treated material discharged from the pre-cleaning Akins 42 is pulverized by a secondary grinding vibratory mill 43. The secondary grinding vibro mill 43 has a capacity of 1000
It is a vibration type crusher of 1 liter, and the supply amount of water containing iron powder dust 14 is 200 to 1000 liter / hr (average:
270 liters / hr), the concentration of iron dust 14 is 50
-80 wt% (average: 65 wt%). By the pulverizing process using the secondary grinding ore vibro mill 43, impurities remaining on the iron powder in the mixture are further pulverized,
It is possible to obtain a processed product of the iron powder dust 14 in which the efficiency of separating iron powder and impurities in the subsequent steps is increased. Here, FIG. 15 shows a change in CaO concentration which is an example of an impurity in the processed material containing the iron powder, and is 2 to 7 wt. %
The CaO concentration in the range of
After washing the primary grinding by the method (FIG. 15B), 0.5
It can be seen that it has decreased to the range of ５5 wt%. However, in such a processed iron powder dust 14,
Since many impurities remain, the purity is not sufficient as a reducing agent when it is used for regenerating iron chloride waste liquid,
It cannot be used as it is. 9 and 10
Using a water washing device 44 and a pickling device 45 as shown in FIG.
It is necessary to further perform a cleaning classification process of the iron powder dust 14. Then, the treated material of the iron dust 14 is washed with the water washing device 4.
4 into the first settling tank 49 via the iron powder dust supply pipe 95. As a result, the iron powder portion having a large particle size in the iron powder dust 14 gradually precipitates, and the first precipitation tank 4
Form a precipitate layer at the bottom of 9. Then, the spiral body 53 disposed in the screw conveyor 50 is rotated by a driving device such as a motor.

At this time, washing water is supplied from the water discharge port 57 of the water supply pipe 55 at an average supply speed of ³ to 25 m ³ / hr, and a downward flow due to the washing water is formed in the screw conveyor 50. As described above, since the treated material of the iron powder dust 14 is supplied from the iron powder dust supply pipe 95 into the first settling tank 49, the specific gravity as a whole including fine iron powder and dust is relatively small. Flow occurs. The rising speed of this overflow flow is 3 to 10 m / hr (average:
When adjusted to the range of 5 m / hr), the iron powder dust 14 is separated and purified. By the above operation, the iron powder dust 14
The fine powder portion inside is washed out of the system as overflow, and the coarse particle portion is selectively discharged from the upper part of the screw conveyor 50 as cleaning iron powder. Since the iron powder dust after the secondary grinding and washing with water is mostly removed, the impurities (CaO) in the iron powder dust 14 are removed.
However, as shown in FIG. 15 (C), the iron powder is removed in the range of 0.3 to 1.7 wt% and the washed iron powder whose particle size distribution is shifted to the coarse particle side is obtained. The washed iron powder thus obtained is put into the second sedimentation tank 51 from the outlet 59 on the upper part of the water washing device 44. As a result, a portion having a relatively large specific gravity in the washed iron powder gradually precipitates, forming a precipitate layer at the bottom of the second precipitation tank 51. On the other hand, the helical body 54 in the screw conveyor 52 is rotated by a motor to discharge the precipitate from the precipitation tank 51 to the outside. At this time, the amount of the washing iron powder supplied from the outlet 59 and the amount of the precipitate discharged from the precipitation tank 51 are adjusted to form an overflow flow in the second precipitation tank 51, and the rising speed thereof is reduced.
It is adjusted to 3 to 10 m / hr (average: 5 m / hr), which is a range suitable for separation and purification. In addition, 9 having a specific gravity of 1.9
An acid solution obtained by diluting 30 to 100 liters / h of 8 wt% concentrated sulfuric acid with the solution after the washing from the secondary washing akins 46 at the subsequent stage is supplied into the screw conveyor 52 from the acid solution inlet 58 of the acid solution supply pipe 56. Thus, a downward flow of the acid solution is formed inside the screw conveyor 52. Here, sedimentation tank 5
The dilution amount of the post-washing solution from the secondary washing Akins 46 is determined so that the pH of the pickling solution in 1 becomes 0.5 to 3.

By the above operation, the washing iron powder is put into the second sedimentation tank 51, and the coarse part where the fine powder part in the washed iron powder is washed with acid is accumulated in the second sedimentation tank 51. At the same time, when the washed iron powder composed of coarse particles is discharged from the second precipitation tank 51 by the screw conveyor 52,
By the acid solution flowing down along the screw conveyor 52 and the overflow flow in the solution, impurities in the washed iron powder are further eluted and removed. Accordingly, the coarse-grained portion including the purified iron powder is selectively discharged from the discharge port 59a on the upper part of the screw conveyor 52, and the supernatant waste liquid in the second sedimentation tank 51 is discharged from the upper part of the second sedimentation tank 51. Is done. Next, as shown in FIG. 8, by using a secondary cleaning akins 46 having the same structure as that of the water washing device 44, the processed material after the acid cleaning process is processed, and the processed material that has become acidic is cleaned. I do. At this time, the washing water consisting of industrial water is 1 to 1
The remaining acid solution can be removed by supplying at a supply speed of 0 m ³ / hr. Then, the treated product after the acid solution treatment is passed through a flash dryer 47 to remove moisture in a 150 to 250 ° C airflow. The particle size distribution of the purified iron powder 15 after drying was measured and is shown in Table 1 below.

[0028]

[Table 1]

A typical composition of such a refined iron powder 15 is that the total Fe containing Fe, FeO, and Fe ₂ O ₃ is 9%.
6 wt% or more, metal Fe is 92 wt% or more, Fe
O is 6 wt% or less, CaO is 0.5 wt% or less, SiO ₂
Was 0.1 wt% or less, and carbon (C) was 0.7 wt% or less. Finally, the refined iron powder 15 is classified using a vibrating sieve 48 having any one of the meshes of Tyler standard sieve in a range of 100 mesh to 150 mesh. Thereby, the refined iron powders 15 having different particle sizes are obtained.
Can be properly used as needed.
For example, the portion above the sieve can be used as purified iron powder for removing copper in etching waste liquid treatment, and the portion below the sieve can be used as purified iron powder for removing nickel. The 100-mesh and 150-mesh Tyler standard sieves are sieves having openings of 147 μm and 104 μm, respectively. Thus, the purified iron powder 15
As shown in FIG. 15 (D), it is possible to obtain a processed product containing the purified iron powder 15 in which impurities (CaO) are significantly reduced to 0.01 to 0.10 wt%, which is a range below the allowable value. . Therefore, in consideration of economic circumstances, the sulfuric acid unit required for obtaining 1 ton of purified iron powder as a product is 10 to 400 units.
The liter and the hydrochloric acid basic unit are set in the range of 25 to 700 liters. Next, an aqueous solution 17 of reduced iron chloride solution is
The method of obtaining is described.

Here, as shown in FIG. 2, an iron chloride-based etching waste liquid 11, which is an etching waste liquid after etching of a lead frame or the like, is supplied to a liquid inlet 25 through a waste liquid supply pipe.
From the ferrous chloride-based etching waste liquid 11 to ^{convert the} ferric ion (Fe ³⁺ ) into ferrous ion (F
e ²⁺ ) to obtain a reduced iron chloride aqueous solution 17. In this reduction operation, the chlorine gas is recovered and used effectively, and in the subsequent step of removing the impurity metal using the purified iron powder 15, the purified iron powder 15 is oxidized and eluted by the ferric ion, and as a result, The purpose is to prevent the Fe ²⁺ concentration from becoming excessive excessively. Here, the iron chloride-based etching waste liquid 11 has a ferric ion concentration and a ferrous ion concentration of 100 to 250 g / each.
Liter, 5 to 70 g / liter, containing chlorine ion (Cl ⁻ ) and HCl, nickel ion (Ni ²⁺ ) as an impurity metal ion, and copper ion (Cu
²⁺ ). The reaction of the iron chloride-based etching waste liquid 11 on the anode plate 23 and the cathode plate 24 in the electrolysis tank 27 is represented by the following equation. Anode: 2Cl ⁻ → Cl ₂ ↑ + 2e ⁻ Cathode: Fe ³⁺ + e ⁻ → Fe ²⁺ That is, chlorine gas is generated in the anode plate 23 and the cathode plate 2
In 4, ferric ions are reduced to ferrous ions, and the overall reaction is represented by the following equation. FeCl ₃ → FeCl ₂ + (１ ／) Cl ₂ ↑

The free energy change ΔG in the overall reaction can be calculated as the amount of change in the free energy G of each component before and after the reaction, and ΔG = + 13784 cal
/ Mol. The theoretical electrolysis voltage E ₀ required for electrolysis can be determined by applying the theoretical formula of E ₀ = ΔG / zF. Where F is the Faraday constant,
z is the number of moles of electrons involved in the reaction, and a theoretical electrolysis voltage E ₀ = 0.5977 volt is obtained based on these values. A range in which chlorine gas is generated while FeCl ₃ is electrolyzed at an electrolysis voltage equal to or higher than the theoretical electrolysis voltage E ₀ and copper ions and nickel ions present in the iron chloride-based etching waste liquid 11 are not reduced. Electrolysis voltage,
For example, it can be set to about 1 volt. And
Considering factors such as current efficiency, DC conversion efficiency, and electrolysis voltage of the electrolysis tank 27, the actually required electric energy is 1000 to 350 per ton of chlorine gas (Cl ₂ ).
The scale, specifications, and the like of the electrolyzer 12 can be determined based on 0 kWh. Next, the electrolysis voltage E, the current density D, and the reduced iron chloride aqueous solution
The method of regenerating the iron chloride-based etching waste liquid will be described in more detail with reference to FIG. As shown in FIG.
After the iron chloride-based etching waste liquid 11 is supplied to a predetermined level to fill the inside of the electrolysis tank 27, an electrolytic voltage E is applied for a predetermined time to make a steady state. Next, the iron chloride-based etching waste liquid 11 is supplied through the waste liquid supply pipe and the liquid inlet 25 connected thereto at a rate of 4.6 liters / hr per pair of electrodes having a width of 1 m ³ (that is, one cell). The reduced iron chloride aqueous solution 17 having a flow rate substantially equal to the supply flow rate Q was taken out from the liquid outlet 26 for supplying the processing liquid at the flow rate Q and discharging the processing liquid.

Then, as shown in FIG. 13 (a), the time at the start of the steady state is set to t ₀ and the electrolytic voltage E is set to 1
It was set to 1.5 V, which is a control range of 4.5 V (volt). At this time, the current density D and the ferric ion concentration C
As shown in FIGS. 13 (b) and 13 (c), they are in a predetermined range of ^{2 to} 40 A / dm ² , and in a range of 10 to 120 g / liter, 50 to 60 g / liter.
Thereafter, chlorine gas is discharged from the chlorine gas discharge port 33, and a desired electrolysis state can be maintained. And FIG.
As shown in FIG. 3, when the ferric ion concentration C fluctuates and deviates from the predetermined range (time t ₁ ), by adjusting the electrolytic voltage E, the predetermined ferric ion concentration C Thus, a reduced aqueous iron chloride solution 17 can be obtained. Also,
In the case where an impurity metal such as copper is deposited on the cathode plate 24, the iron chloride-based etching waste liquid 11 is supplied to the copper deposition portion, and copper is produced by the following reaction between ferric chloride and copper in the liquid. Can be redissolved. 2FeCl ₃ + Cu → 2FeCl ₂ + CuCl _{2 As} another method, as shown in the range of the time (t _{2 to} t ₃ ) in FIG. 13, the electrolytic voltage E is held at zero or the time (t _{4 to} t ₅₎ As shown in the range of), it is also possible to redissolve the deposited copper by applying a reverse voltage for a predetermined time. The time (t ₂ ) in FIG.
Since the operation will be stable thereafter, the rest is omitted.

The temperature of the electrolytic solution in the electrolysis step is controlled in the range of 30 to 100 ° C. When the temperature of the electrolytic treatment liquid is lower than 30 ° C., the electric resistance increases, and copper, nickel, and the like are easily deposited. On the other hand, when the temperature of the electrolytic treatment liquid exceeds 100 ° C., a boiling phenomenon of the electrolytic treatment liquid occurs, which is not preferable. The ferric ions in the reduced iron chloride aqueous solution 17 obtained by this electrolysis step are, for example, as shown in the schematic diagram of the transition of each ion concentration shown in FIG. While the ferric ion concentration was 207 g / liter (FIG. 14A), the concentration after the treatment was in the range of 50 to 60 g / liter (FIG. 14B). On the other hand, nickel ions (Ni ²⁺ ),
And the concentration of copper ions (Cu ²⁺ ) and the like are maintained substantially at the values before the treatment. The nickel ions and copper ions are indicated by M ^{n +} in FIG. As described above, since the concentration of the ferric ion in the reduced aqueous iron chloride solution 17 is set to a level slightly higher than the concentration of the impurity metal ion, the impurity metal ion may be reduced during the electrolysis. And efficient electrolysis can be performed without wasting power. Here, Table 2 shows the electrolysis conditions in the steady state of the above-described electrolyzer 12 and the results thereof. Become.

[0034]

[Table 2]

Next, as shown in FIG. 12, a reduced iron chloride aqueous solution 17 which is an example of an iron chloride-based waste liquid obtained by electrolyzing the iron chloride-based etching waste liquid 11 is supplied to a stirring tank 18, A method for reducing and removing impurity metal ions such as copper and nickel contained in the reduced iron chloride aqueous solution 17 using the purified iron powder 15 purified from the powder dust 14 will be described below. First, as shown in FIG.
5 is supplied into the stirring tank 18 through the upper opening of the stirring tank 18, and the reduced iron chloride aqueous solution 17 is supplied to the stirring tank 18 through the waste liquid supply valve 86 and the processing liquid inlet 78. Thereafter, the circulating pump 79 is driven to suck the iron powder treatment liquid 19 passing through the fluidized bed via the first circulating flow control valve 81 and the second circulating flow control valve 82, and the stirring tank 18 The iron powder treatment liquid 19 is supplied to the stirring tank 18 at an angle so as to form a swirling flow through the supply flow control valve 83 provided at the bottom of the tank, and the iron powder processing liquid 19 is supplied from the bottom to the top in the stirring tank 18. A circulating flow is created. This makes it possible to form a fluidized bed by floating the iron powder that easily precipitates at the bottom of the stirring tank 18, and to improve the efficiency of the purified iron powder 15 and the reduced iron chloride aqueous solution 17 without dead space in the tank. Mixing can be realized.

The distribution of the purified iron powder 15 and the residence time are different in each of the first partition 71 to the third partition 73 arranged so as to have different horizontal cross-sectional areas. For this reason, the iron powder concentration of the iron powder processing liquid discharged from the first partition 71 is lower than the iron powder concentration of the iron powder processing liquid discharged from the second partition 72. If necessary, the discharge amount of the iron powder treatment liquid 19 having a different iron powder concentration and a different degree of reduction reaction is adjusted by the first and second discharge flow control valves 92 and 93, respectively. hand,
It is possible to control the properties of the discharged iron powder treatment liquid 19. Thus, while forming a fluidized bed in which the solid-liquid ratio of the slurry is 1: 0.6 to 1: 0.7 in the stirring tank 18, the ferric ion remaining by the reaction with the purified iron powder is removed. In addition to ferrous ions, a reduction reaction of metal ions, such as copper ions and nickel ions, having a lower ionization tendency than iron can be caused as shown below, and the iron powder treatment liquid 19 can be obtained. Chromium ions, which have a lower ionization tendency than iron, are similarly reduced by the purified iron powder. 2FeCl ₃ + Fe → 3FeCl ₂ CuCl ₂ + Fe → FeCl ₂ + Cu ↓ NiCl ₂ + Fe → FeCl ₂ + Ni ↓

Such a reduction reaction also depends on the iron powder concentration in the slurry, the surface area of the iron powder, the slurry temperature, the chloride ion concentration, etc., and is appropriately adjusted by these factors or the addition of a pH adjuster. be able to. In the step of removing impurity metal ions, the reduced iron chloride aqueous solution 1
The purified iron powder 15 is eluted in 7 to generate ferrous ions. However, the reduced iron chloride aqueous solution 17 has been subjected to electrolysis to remove the ferric ions in advance or the concentration thereof has been reduced. The elution amount of the iron making powder 15 can be suppressed to a required minimum, and the removal of the impurity metal ions is not hindered, so that the iron powder processing liquid 19 that has been efficiently purified can be obtained.
Can be obtained. Then, as shown in FIG. 14C, the concentration of each metal ion in the iron powder treatment liquid 19 is reduced aqueous iron chloride aqueous solution 17 (FIG.
From (b)), the amount of the impurity metal ion ( ^{Mn +} ) is reduced. Next, the iron powder treatment liquid 19 discharged from the stirring tank 18 is removed from the iron powder and other impurities to obtain an iron powder treatment liquid containing a large amount of ferrous chloride. The iron powder treatment liquid containing a large amount of
1 and blown or bubbled chlorine gas generated by the electrolyzer 12 or the like to oxidize a part or all of the contained ferrous ions into ferric ions to regenerate the etching solution 20. obtain. That is, the chlorine gas generated by the electrolyzer 12 is blown into the chlorination device 21 as an oxidizing agent for the ferrous ions to oxidize the ferrous ions remaining in the iron powder treatment liquid. And
As shown in FIG. 14D, the regenerated etching solution 20 in which the impurity metal ions are removed and the FeCl ₃ concentration is adjusted to 560 to 730 g / liter can be obtained. In this case, there is also an advantage that the chlorine gas generated in the waste liquid treatment equipment 10 can be effectively used in the own equipment.

As described above, in the first embodiment, unlike the conventional method in which ferric ions are reduced in advance using iron powder, the method is accompanied by the elution of iron powder in the reduction step. When the etching solution having a predetermined iron ion concentration is regenerated with a small increment of iron ions, the amount of the diluting solution for adjusting the iron ion concentration can be kept within a necessary minimum range. In addition, the amount of iron powder used in the reduction and removal of copper ions and nickel ions can be significantly reduced, the total amount of iron powder used in all processes can be reduced, and costs related to iron powder can be reduced. Chlorine gas generated at the time can be recovered and effectively used in the subsequent chlorination step, so that the cost of chlorine gas can be reduced accordingly.
Further, since the amount of the diluting liquid used in the regeneration treatment of the iron chloride-based etching waste liquid 11 is not significantly increased, the waste liquid treatment equipment 10 can be made compact.

(Second Embodiment) FIG. 1 shows a method of regenerating an iron chloride-based etching waste liquid according to a second embodiment of the present invention.
Referring to FIGS. 6 to 19, the details will be described below.
The difference from the equipment configuration to which the method for regenerating the waste iron chloride-based etching waste liquid according to the first embodiment shown in FIG. Since the second stirring tanks 115 and 119 are used, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the method of regenerating the iron chloride-based etching waste liquid according to the second embodiment, a conventional stirring blade type stirring tank is used for the first stirring tank 115, but the fluidized bed shown in FIG. It is preferable to use a stirring tank 18 of a mold type. In some cases, as described above, after the electrolysis method is applied to the iron chloride-based etching waste liquid, the method for regenerating the iron chloride-based waste liquid according to the second embodiment is applied. It is also possible. As shown in FIG. 16, the etching waste liquid treatment equipment 110 used in the method for regenerating an iron chloride-based etching waste liquid according to the second embodiment includes:
A copper removing device 113 for removing copper from an etching waste liquid, a nickel removing device 122 for removing nickel and chromium from an etching waste solution from which copper has been removed, a device for removing suspended impurities such as carbon and silica (not shown), And a chlorinating apparatus 21 (see FIG. 1) that oxidizes the processing liquid from which is removed and uses it as an etching liquid. Hereinafter, these will be described in detail.

The decoppering device 113 includes an etching waste liquid tank 111 and a required amount of a pH adjusting agent supplied from an etching waste liquid tank 111 and a pH adjusting agent tank 112, and iron fed from an iron powder storage tank 114 via a screw feeder 118. Powder, water source not shown (for example, tap water)
Mixing tank that mixes the water supplied from the furnace and a part of the solid collected in the copper removing device 113 to discharge a suspension-like iron powder mixed solution 1A containing reduced copper. 115
And a liquid cyclone 116 supplied with the iron powder mixture 1A from the first stirring tank 115 and separating it into a copper removal treatment liquid 1B containing relatively small particles and a copper-containing iron powder mixture 1C containing large particles. And a pump 1 for transporting the iron powder mixture 1A discharged from the first stirring tank 115 to a liquid cyclone 116 via a cone tank (inverted conical tank) 121.
27, a first Ekins classifier 117 for classifying and washing the copper-containing iron powder mixture 1C discharged from the lower part of the liquid cyclone 116 to obtain a powdery solid, and a part of the solid And a second Akins classifier 117a for taking out, re-cleaning, and forming copper powder. Here, the first stirring tank 115 is a substantially cylindrical FRP container, and is provided with a stirring blade 128 in the tank for forcibly stirring the slurry-like iron powder mixed solution 1A in the tank. The treated iron powder mixture 1A is discharged from an outlet 115a at the top of the tank. First and second Akins classifier 11
7, 117a are dust sedimentation tanks 120, 120a to which an iron powder mixed solution 1A containing reduced copper is supplied, respectively.
Dust sedimentation tanks 120, 1
It has a solid riser tube (not shown) for classifying and washing while draining by raising the solid matter in 20a into a pipe and raising the solid matter, and a sprayer (not shown) for washing water. In the first and second Ekins classifiers 117 and 117a, the fine powder portion in the solid is classified in the dust settling tanks 120 and 120a, and the solid has a relatively large particle size and excess moisture is removed. The solid matter is discharged from an upper end of a solid riser (not shown).

The nickel removing device 122 is an example of an iron chloride waste liquid.
Copper removal liquid 1B discharged from the iron powder storage tank 114a, the iron powder supplied from the iron powder storage tank 114a, and the nickel removal device 12
A second stirring tank 119 for discharging a primary iron powder treatment liquid 2B in which nickel ions, chromium ions, and the like contained by mixing with the recovered solid matter in the second 2 are reduced, and iron in the iron powder storage tank 114a. A screw feeder 118a for supplying the powder to the second stirring tank 119, the supplied primary iron powder treatment liquid 2B is converted into a nickel removal treatment liquid 2C containing iron powder fine particles, and iron powder particles on which nickel is precipitated. Cyclone 11 to be separated into mixed nickel-containing iron powder mixture 2D
6a, a pump 127a for transporting the primary iron powder treatment liquid 2B discharged from the second stirring tank 119 to the liquid cyclone 116a via the cone tank 121a, and a nickel-containing iron powder mixed discharged from the liquid cyclone 116a. An Akins classifier 117b for washing the liquid 2D with water to obtain a powder of nickel and nickel-adhered iron powder; have. As shown by the solid line d in FIG. 16, depending on the type of the iron chloride-based etching waste liquid, the second stirring tank 11 may be used.
9 and the etching waste liquid tank 1
A part or all of the etching waste liquid may be directly supplied from 11 as needed. Second stirring tank 119
As shown in FIG. 17, the first partition 130 to the fifth partition 134 each have a volume of 17 m ³ and a maximum inner diameter of about 3 as shown in FIG. .2 m and can hold about 21 tons of iron powder for etching waste liquid treatment.

Inside the second stirring tank 119 and at a lower position, the stirring blade 12 for stirring the copper removal liquid 1B, which is an example of the supplied iron chloride waste liquid, and iron powder as necessary.
8a, and a motor 129 for rotating and driving the stirring blade 128a is provided at the upper part. Normally, the slurry is not stirred by the stirring blade 128a.
E is taken out and the lower part is mainly agitated by liquid circulation supplied by a circulation pump 126, so that a slurry having a solid-liquid ratio of 1: 1 which is a weight ratio of iron powder to liquid is rotated by a conventional motor. It has the ability to process at 1.5 times the processing speed as compared to a stirring type reaction tank with stirring blades. The first part, which is the uppermost part of the second stirring tank 119,
The partitioning section 130 is an area formed of a straight cylindrical section having a maximum horizontal cross-sectional area, the upper end opening of which is open to the atmosphere, and the purified iron powder produced by the above-described method is placed in the stirring tank 119 from above. 15 can be inserted. On the other hand, the second partition 131 following the first partition 130
Is a region composed of a tapered portion whose diameter gradually decreases in the downward direction. On the other hand, a lower portion of the second partition 131 is formed with a third partition 132 formed of a straight cylindrical portion having the same cross-sectional area as the lower end of the second partition 131.
A fourth partition 133 formed of a tapered portion is continuously provided at a lower end of the fourth partition 133, and a fifth partitioned portion 134 formed of a small-diameter straight cylindrical portion is continuously provided at a lower end of the fourth partition 133. Then, in the third to fifth partitions 132 to 134, the supplied iron powder, the iron powder treatment liquid 2E supplied from below, and the copper removal treatment liquid 1B obtained by treating the iron chloride-based etching waste liquid are shown in FIG.
As shown by hatching in FIG. 7, a fluidized bed with a high iron powder density is formed. In the first and second compartments 130 and 131 having a low ascending flow velocity, the descending velocity of the iron powder is faster than the flow velocity of the processing liquid, and therefore, the iron powder separating section (free board) having an extremely small iron powder density. Is formed.

First partition 13 forming the iron powder separating section
Portions 145 and 145a of the processing liquid are respectively provided on the side walls of the zero and second partitions 131, and the processing liquid inlet 145b is provided on the side wall of the fifth partition 134 forming the lower part of the fluidized bed. Is provided. The processing liquid partial outlets 145 and 145a and the processing liquid inlet 145b
Are connected to each other by a processing liquid circulation pipe 145d having a circulation pump 126 in the middle. Therefore, by driving the circulating pump 126, the iron powder processing liquid 2E having a low iron powder content is respectively discharged from the first and second compartments 130 and 131 through the processing liquid partial outlets 145 and 145a. Take out and then process liquid circulation pipe 1
The self-circulating flow is formed in the second stirring tank 119 by flowing the iron powder processing liquid 2E into the fifth partition 134 through the processing liquid inlet 45d and the processing liquid inlet 145b. To the fifth divisions 132 to 134. Further, at the upper end of the processing liquid circulation pipe 145d,
First and second circulating flow control valves 13 for controlling the flow rate of the iron powder processing liquid 2E passing vertically through the processing liquid circulation pipe 145d through the processing liquid partial outlets 145 and 145a.
5, 136 are provided, and a processing liquid circulation pipe 145 is provided.
At the lower end of d, a supply flow control valve 143 is provided.
These first and second circulation flow control valves 135, 136,
By using the supply flow control valve 143, the flow rate of the circulating liquid can be easily controlled. Accordingly, the supply pipe 1 for the copper removal treatment liquid provided with the waste liquid supply valve 142 in the middle thereof
Irrespective of the supply amount of the copper removal treatment liquid 1B supplied through the nozzle 47, the fluidized state of the iron powder supplied to the second stirring tank 119 by the circulating flow is maintained in an appropriate range, and the fluidized bed is maintained. Can be formed. When a stirring blade take-out device (not shown) is provided and the stirring blade 128a is not used, the stirring device can be removed from the second stirring tank 119.

The iron powder treatment liquid 2E or the like is discharged to the fifth partition 134, which is provided at the lowermost part of the second stirring tank 119 and is composed of a small-diameter straight tube part in which the iron powder tends to precipitate. Therefore, iron powder and the like can be actively rolled up, so that generation of a dead space in the second stirring tank 119 is suppressed. First to form iron powder separation part
On the side walls of the partitioning section 130 and the second partitioning section 131, processing liquid outlets 145e and 145f for the above-described primary iron powder processing liquid 2B are provided, respectively. In the middle, there is a cone tank 1
21a (see FIG. 16) and a processing liquid transfer pipe 127c having a pump 127a are connected.
The outlet side of 27c is connected to the hydrocyclone 116a. Here, the discharge side of the fixed-quantity pump 127a is partially returned to the cone tank 121a to adjust the overall flow rate. Note that the flow rate of the primary iron powder processing liquid 2B discharged from the processing liquid discharge ports 145e and 145f depends on the first discharge provided at an intermediate position of the processing liquid transfer pipe 127c following the respective processing liquid discharge ports 145e and 145f. It can be adjusted by the flow control valve 138 and the second discharge flow control valve 139. As described above, the primary iron powder treatment liquid 2B having different component characteristics can be taken out from the plurality of compartments by selecting the primary iron powder treatment liquid 2B from the reaction compartments having different treatment conditions as needed.

Further, the purified iron powder 1 in the second stirring tank 119
When 5 is insufficient, the purified iron powder 15 is supplied from the upper part of the stirring tank 119. Further, a discharge pipe 146a provided with a bottom discharge valve 146 for discharging solids and the like precipitated at the bottom is provided at the bottom of the second stirring tank 119.
Is provided, from which solids and the like can be extracted. Table 3 below shows the processing conditions and processing results of the above-described second stirring tank 119 together with comparative examples.

[0046]

[Table 3]

Subsequently, the etching waste liquid treatment equipment 11
A method for treating an iron chloride-based etching waste liquid using the method of recycling the iron chloride-based etching waste liquid according to the second embodiment of the present invention using 0 in the second half will be described in more detail. Here, in the stirring process of the first stirring tank 115, an example is shown in which a stirring blade according to a conventional method is used, but it is not possible to change to the stirring tank 18 using a fluidized bed according to the first embodiment described above. Naturally, this is possible, thereby providing a more efficient and economical method of regenerating an iron chloride-based etching waste liquid. First, as shown in FIG. 16, a predetermined amount of iron powder is placed in the first stirring tank 115 and the second stirring tank 119,
14, 114a to the screw feeders 118, 118
It is input in advance via a. Such iron powder for the reduction treatment of impurity metal ions has, for example, a particle size of 44 to 250.
μm can be used. Further, a shadow mask, a lead frame, and the like are subjected to etching treatment for the iron chloride-based etching waste liquid, and ferric chloride (FeCl ₃ ) in the liquid is etched.
, An aqueous solution containing a metal ion such as copper, nickel, and chromium is used.

The iron chloride-based etching waste liquid is supplied from the etching waste liquid tank 111 to the first stirring tank 115 via a pump, and the stirring blade 128 is rotated so that the iron powder is put into the iron chloride-based etching waste liquid. The suspension is mixed to form a mixed slurry. Then, in this mixed slurry, copper ions having a lower ionization tendency than iron (Fe) are reduced to precipitate copper, and iron powder is eluted as iron ions in the liquid, and is treated with iron powder. It is discharged as an iron powder mixed solution 1A containing iron powder. If necessary, a pH adjuster such as hydrochloric acid is added to the mixed slurry to adjust the pH value of the mixed slurry to, for example, a range of 0.5 to 1.5, so that the rate or efficiency of the reduction reaction is increased. Can be maintained in a predetermined range. Next, the iron powder mixed solution 1A is taken out from an outlet 115a provided in the upper part of the first stirring tank 115 and fed into the cone tank 121. The mixed liquid 1A of iron powder in the cone tank 121 is supplied to the liquid cyclone 116 via the pump 127. The liquid cyclone 116 separates the iron powder mixture 1A into a copper-containing iron powder mixture 1C having a large amount of iron powder containing copper and a copper removal treatment liquid 1B from which most of copper and iron powder have been removed. Copper-containing powder mixture 1C discharged from the lower part of liquid cyclone 116
Are the first and second Akins classifiers 117, 117a
, And finally, copper powder 117e is obtained. In addition, a part of the slurry containing a large amount of iron powder that has been treated by the first Akins classifier 117 may be collected and supplied to the first stirring tank 115.

On the other hand, the copper removal treatment liquid 1 B discharged from the upper part of the hydrocyclone 116 is supplied to the nickel removal device 122.
And impurity metals such as nickel and chromium are removed by the following procedure. First, as shown in FIGS. 16 and 17, the copper removal treatment liquid 1B is supplied to the second stirring tank 119 via the waste liquid supply valve 142, and the purified iron powder 15 is supplied from the iron powder storage tank 114a to the screw feeder 118.
Feed continuously via a. Here, the stirring blade 128a is rotated by the motor 129 at a predetermined rotation speed, for example, 5-6.
It is also possible to drive at a low rotational speed of 0 rpm. However, the stirring of the second stirring tank 119 is performed by the stirring blades 12.
8a, the specific gravity of the iron powder in the copper removal treatment liquid 1B is significantly larger than that of the liquid part.
In this state, the iron powder cannot be sufficiently uniformly dispersed, and the iron powder precipitates and accumulates on the bottom of the second stirring tank 119, so that a dead space occurs and the reaction efficiency between the iron powder and the copper removal treatment liquid. Cannot be maintained at a predetermined level. In addition, when the output of the motor 129 is increased and the stirring blade 128a is rotated at high speed to strongly stir the copper removal treatment liquid 1B, the dead space in the second stirring tank 119 is reduced, and the iron powder is uniformly dispersed. However, the power consumption of the motor 129 becomes unnecessarily large, and the tank wall of the second stirring tank 119 made of FRP or the like becomes severely worn. As a result, the agitating blade 128a is worn.

Therefore, the stirring blade 128a is not used, and if necessary, the stirring blade 128a is removed from the second stirring tank 119, and the circulation pump 126 is driven as shown in FIG. 1 circulation flow control valve 13
5. The iron powder treatment liquid 2E containing a small amount of iron powder is sucked through the second circulation flow control valve 136, and the second stirring tank 11
9, the iron powder treatment liquid 2E is supplied to the second stirring tank 119 at an angle so as to form a swirling flow through a supply flow control valve 143 provided at the lowermost portion of the second stirring tank. Tank 1
A circulating flow is created in 19 from bottom to top. As a result, iron powder that easily precipitates at the bottom of the second stirring tank 119 can be floated, dead space in the tank is eliminated, and even when the motor output of the circulating pump 126 is small, the iron powder and copper removal processing are performed. Efficient mixing with the liquid 1B can be realized. In addition, since the first partitioning section 130 has a straight cylindrical shape and is located at an upper position, and the second partitioning section has a tapered shape, the distribution state and residence time of the iron powder are different, and the first partitioning section 130 The iron powder concentration of the discharged iron powder treatment liquid is the second
It becomes lower than the iron powder concentration of the iron powder treatment liquid discharged from the partition 131. When necessary, the discharge amounts of the iron powder treatment liquids having different iron powder concentrations and different degrees of reduction reaction are determined by the first and second discharge flow control valves 138, 1
It is possible to control the properties of the primary iron powder treatment liquid 2B discharged to the cone tank 121a by adjusting with 39. In this embodiment, the stirring blade 128a was rotated at a low speed while forming a desired circulation flow in the second stirring tank 119, and the maximum peripheral speed was maintained at 1 m / s. With this, it is possible to generate a swirl flow in addition to the upward flow, thereby improving the stirring efficiency. In this case, if the stirring blade 128a is rotated at a medium speed or a high speed, the second stirring tank 119 and the stirring blade 128a are undesirably worn. In this manner, the reduction reaction of nickel ions, chromium ions, and the like by the iron powder is caused as described below, and the primary iron powder treatment liquid 2B can be obtained. 2FeCl ₃ + Fe → 3FeCl ₂ NiCl ₂ + Fe → FeCl ₂ + Ni ↓

Therefore, such a reduction reaction is also affected by the iron powder concentration in the slurry 2A in the second stirring tank 119, the surface area of the iron powder, the temperature of the slurry 2A, the chloride ion concentration, etc., and these factors or It can be appropriately adjusted by adding a pH adjuster or the like. At this time, the solid-liquid weight ratio of the slurry 2A in the second stirring tank 119 was 1: (0.6 to 0.7) as shown in Table 3. The obtained primary iron powder treatment liquid 2B is sent to the cone tank 121a, and is supplied to the liquid cyclone 11 via the pump 127a.
By 6a, the mixture is separated into a nickel removal treatment liquid 2C and a nickel-containing iron powder mixed liquid 2D. Part of the nickel-iron-containing powder mixture 2D discharged from the lower part of the hydrocyclone 116a is returned to the second stirring tank 119 again, and most of the liquid is sent to the Ekins classifier 117b, where nickel and nickel adhere. The separated iron powder 117f is separated. After the coagulant supplied from the coagulant tank 125 is added in the agitation adjustment tank 124, the nickel removal treatment liquid 2C discharged from the upper part of the liquid cyclone 116a is sent to the next device for removing suspended impurities (not shown). It is supposed to be. The nickel removal treatment liquid 2C containing suspending impurities, such as carbon (carbon) and silica (silicon dioxide), is treated by a solid-liquid separator such as a decanter, and the suspended impurities and the raw material of the etching solution are removed. It is separated into the next iron powder processing liquid 2F (corresponding to the iron powder processing liquid 19 in FIG. 1), and finally becomes an etching liquid 20 which is chlorinated and regenerated.

Here, the comparative example shown in Table 3 shows a circulating flow generating mechanism in which the volume as a reaction tank is 11 m ³ , the maximum flow velocity (peripheral velocity) of the slurry is 6 m / s, and the iron powder holding capacity is 6 tons. This is an example in the case of using a mechanical stirring tank of a stirring type having no stirring blade. In the second embodiment, the maximum flow velocity can be reduced from 6 m / s to 1 m / s as compared with the comparative example shown in Table 3, and the solid-liquid ratio can be reduced from the conventional 1: 3 to 1: (0.6 to
0.7). In this way, the processing efficiency can be improved, and the second stirring tank 1
19 can be reduced, and the cost for maintenance of the apparatus can be reduced. In addition, since iron powder having a relatively large particle size can be used, raw material costs can be reduced.

Next, a third stirring tank 150 which is a modified example of the second stirring tank 119 used in the method of regenerating the iron chloride etching waste liquid according to the second embodiment of the present invention described above.
Will be described. As shown in FIGS. 18 and 19, the third stirring tank 150 is a reaction composed of three regions of a first partition 151 to a third partition 153 each having a different horizontal cross-sectional area in the vertical direction. In a third stirring tank 150, a predetermined amount of iron powder for iron chloride-based etching waste liquid treatment or purified iron powder 15 produced by the above-described iron powder refining facility 16 is held in a third stirring tank 150, not shown. The iron powder consumed by the operation of the third stirring tank 150 is continuously supplied from the iron powder supply device. At the inner bottom of the third stirring tank 150, the third partition 15
3 is provided with a partition board 155 for dividing the fluid supply section 3 from the fluid supply section 154 thereunder. On the partition 155, a large number of nozzles 156 called “twires” for dispersing and discharging the processing liquid supplied from the fluid supply unit 154 below the partition 155 in the horizontal direction on the partition 155 are arranged in a zigzag or grid pattern. ing. Further, the first partition 151 serving as an iron powder separating unit is provided with a takeout port 157 for taking out an amount of the iron powder treatment liquid 3A necessary for forming a fluidized bed.

Then, the iron powder processing liquid 3A taken out
Is supplied to the supply port 159 provided on the side surface of the fluid supply unit 154 via the circulation pump 158, and the third stirring tank 1
A circulating flow for fluidizing the iron powder in 50 is formed. At the bottom and / or the side of the fluid supply unit 154, a supply port 160 of a copper removal treatment liquid for supplying the copper removal treatment liquid 1B processed by the first stirring tank 115 of the preceding stage and its attached equipment is provided. A discharge port 161 for discharging the iron powder processing liquid 3B (corresponding to the iron powder processing liquid 19 in the first embodiment) is disposed in the first partition 151 above the third stirring tank 150. Is provided.
In an example using such a third stirring tank 150,
When the circulation pump 158 is operated, the treatment liquid supplied to the fluidized bed via the nozzle 156 is discharged, so that the iron powder in the third stirring tank 150 is maintained in a fluidized state. In this modification, the maximum flow rate of the slurry is 6 m compared to the case of using the stirring tank according to the comparative example, which is configured according to the specifications shown in Table 3 and stirs the iron powder and the processing liquid using the stirring blade. / S to 0.25 m / s, and the processing can be performed by increasing the solid-liquid ratio to 1: 1 higher than 1: 3. Table 3
As shown in the item of iron powder particle size restriction, in the second embodiment and its modification, the formation of a circulating system of the processing liquid therein makes it easy to control the stirring conditions. The particle size of the resulting iron powder can be obtained in a wide range from small to medium. On the other hand, in the case of the comparative example, it is understood that the material is limited to small grains and the raw material cost is increased.

[0055]

In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the iron powder treatment liquid passed through the fluidized bed is circulated and supplied from the bottom of the stirring tank to form a fluidized bed of iron powder. The following effects are obtained. An amount of the fluid medium necessary to maintain the state of the fluidized bed in an appropriate range can be supplied by the iron powder treatment liquid flowing out from the upper part of the stirring tank. Therefore, when the supply speed of the supplied iron chloride waste liquid is insufficient, the iron powder is brought into a good fluidized state by a self-circulating flow that uses a part of the iron powder treatment liquid formed in the stirring tank. If the supply speed of the iron chloride waste liquid is excessive, the reduction treatment of the iron chloride waste liquid is always performed under stable conditions by adjusting by reducing the self-circulation amount of the iron powder treatment liquid. It can be performed. It is possible to reduce the dead space of the agitation tank by arranging the discharge position of the iron powder treatment liquid appropriately, while increasing the diameter of the agitation tank upward, and efficiently using the minimum equipment. The removal efficiency of impurity metal ions in the iron chloride waste liquid can be increased. Since the movement of the iron powder in the fluidized bed is homogenized, local wear due to the flow of the iron powder does not occur as compared with the case of using a fluidized bed with a mechanical stirring method. The service life can be increased and the maintenance cost can be reduced. A good stirring state between the iron powder and the iron chloride waste liquid can be ensured with a fluidized bed in a relatively narrow space. For this reason, the entire apparatus can be made compact.

Here, in particular, when the iron chloride waste liquid is supplied from the bottom of the stirring tank, the treatment liquid does not contain the iron chloride waste liquid, and the supplied iron chloride waste liquid also forms a fluidized bed. Can help. Further, in the method for regenerating an iron chloride-based etching waste liquid according to the present invention, it is preferable that the diameter of the upper portion of the stirring tank be larger than that of the main body portion, whereby the speed of the fluid medium rising in the stirring tank is reduced to reduce the iron powder. Can promote precipitation. Also, an iron powder separation part can be formed on the top,
Even if the flow rate in the tank slightly fluctuates, the upper end of the fluidized bed can be maintained so as not to exceed a predetermined position, iron powder is less mixed into the iron powder processing solution, and removal of impurity metal ions under stable conditions And the efficiency of removing impurity metal ions can be further improved. In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, a part or most of the ferric ions in the raw waste liquid is reduced to ferrous ions in advance by electrolysis treatment of the supplied iron chloride-based waste liquid. It is also possible. As a result, since the ferric ions are reduced by the cathodic reaction, the total iron ion concentration of the ferrous ions and the ferric ions in the liquid does not change. Therefore, in the regeneration treatment of the iron chloride waste liquid, it is not necessary to use a large amount of diluting liquid (specifically, water) in order to set the concentration of ferric ion to a predetermined concentration, and the cost of processing the surplus liquid is eliminated. And the processing equipment can be made more compact. Further, since the amount of iron powder used in the regeneration treatment of the iron chloride waste liquid can be reduced, the cost of treating the iron chloride waste liquid can be reduced. Further, in the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the electrolytic voltage of the iron chloride-based etching waste liquid in the electrolysis treatment can be controlled to a specific range. Thereby, it is possible to reduce the ferric ion without precipitating the impurity metal ions such as copper and nickel contained in the iron chloride-based etching waste liquid, and to more efficiently regenerate the iron chloride-based waste liquid. it can.

In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the interelectrode distance between the anode plate and the cathode plate of the electrolytic cell in the electrolytic treatment can be set to a specific range. Inhibition of the generated chlorine gas into the cathode chamber can be suppressed, oxidation of ferrous ions can be suppressed, and an increase in electrolysis voltage can be suppressed. In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the iron chloride-based etching waste liquid is supplied to a cathode chamber side of the electrolysis tank, which is partitioned into an anode chamber side and a cathode chamber side by a diaphragm, and is treated. The reduced aqueous solution of reduced iron chloride can also be taken out from the other part on the cathode chamber side. Thereby, interference between the chlorine gas generated in the anode plate and the supplied iron chloride etching waste liquid is suppressed, and efficient electrolysis can be performed. In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the concentration of ferric ion in the reduced aqueous iron chloride solution may be 10 to 120 g / liter. Thereby, impurity metal ions such as copper and nickel in the aqueous iron chloride solution are not reduced, and there is no problem in the subsequent regeneration processing, and the cost of the subsequent regeneration processing can be reduced. . In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, chlorine gas generated in the electrolysis treatment is blown into the iron powder treatment liquid discharged from the stirring tank, and ferrous ions contained in the iron powder treatment liquid are blown. Can be oxidized to ferric ions. Thereby, the concentration of ferric ion in the iron powder treatment liquid from which the impurity metal ions have been removed can be adjusted to a desired value without generating unnecessary by-products, and the necessary components and concentrations can be adjusted. A regenerated solution of the aqueous iron chloride solution can be obtained efficiently.

[0058] In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, iron powder dust is recovered by a wet method from dust containing impurities such as CaO generated from a steelmaking furnace, and the iron powder dust is pulverized. And then washed with water and then pickled. Thereby, it is possible to inexpensively regenerate the iron chloride waste liquid by using high-purity purified iron powder with little variation obtained by treating dust generated from the steelmaking furnace. In the method for regenerating an iron chloride-based etching waste liquid according to the present invention, the pickling of iron powder dust is performed in a process of being gradually inclined and discharged by a screw conveyor having an acid liquid injection port provided at an upper portion thereof, which is inclined in a precipitation tank. It is also possible. As a result, iron powder used for the reduction treatment of the iron chloride waste liquid can be obtained in large quantities and inexpensively by the continuous treatment, and the regeneration treatment of the iron chloride waste liquid can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a conceptual explanatory diagram of a waste liquid treatment facility to which a method of regenerating an iron chloride-based etching waste liquid according to a first embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram of an electrolyzer of the waste liquid treatment facility.

FIG. 3 is a schematic diagram of an arrangement of a supply position of an iron chloride-based etching waste liquid and an extraction position of a reduced iron chloride aqueous solution in an electrolyzer.

FIG. 4 is a schematic view showing the arrangement of a supply position of an iron chloride-based etching waste liquid and an extraction position of a reduced iron chloride aqueous solution in an electrolyzer.

FIG. 5 is a schematic view showing the arrangement of a supply position of an iron chloride-based etching waste liquid and an extraction position of a reduced iron chloride aqueous solution in an electrolyzer.

FIG. 6 is a schematic view showing the arrangement of a supply position of an iron chloride-based etching waste liquid and an extraction position of a reduced iron chloride aqueous solution in an electrolysis apparatus.

FIG. 7 is a schematic diagram of an arrangement of a supply position of an iron chloride-based etching waste liquid and an extraction position of an aqueous solution of reduced iron chloride in an electrolysis apparatus.

FIG. 8 is an explanatory diagram of a configuration of an iron powder refining facility of the waste liquid treatment facility.

FIG. 9 is a side sectional view of a water washing device and an acid pickling device in the iron powder refining facility.

FIG. 10 is a sectional view taken along line II of FIG. 9;

FIG. 11 is a layout view of an iron powder collecting facility for obtaining iron powder dust.

FIG. 12 is an explanatory view of a stirring tank of the waste liquid treatment equipment.

13 (a), (b), and (c) are time transition diagrams of an electrolysis voltage, a current density, and a ferric ion concentration in an electrolyzer, respectively.

FIGS. 14 (a), (b), (c), and (d) are schematic diagrams showing changes in ion concentration in a regeneration treatment of an iron chloride-based waste liquid.

FIG. 15 is a transition diagram of CaO concentration of iron powder dust.

FIG. 16 is an explanatory diagram of an etching waste liquid treatment facility to which a method for regenerating an iron chloride-based etching waste liquid according to a second embodiment of the present invention is applied.

FIG. 17 is a sectional view of a second stirring tank used for the facility.

FIG. 18 is a side sectional view showing another example of the second stirring tank.

FIG. 19 is a view taken along the line II-II in FIG. 18;

[Description of sign]

REFERENCE SIGNS LIST 10 Waste liquid treatment equipment 11 Iron chloride etching waste liquid 12 Electrolyzer 13 Converter 14 Iron powder dust 15 Purified iron powder 16 Iron powder purification equipment 17 Reduced iron chloride aqueous solution 18 Stirrer tank 19 Iron powder treatment liquid 20 Etching liquid 21 Chlorine treatment equipment Reference Signs List 23 anode plate (anode) 24 cathode plate (cathode) 25 liquid inlet 26 liquid outlet 27 electrolysis tank 28 DC power supply unit 29 control unit 30 diaphragm 31 anode room 32 cathode room 33 chlorine gas outlet 34 electrolysis tank 35 electrolysis tank 36 Electrolysis tank 37 Electrolysis tank 37a Electrolysis tank 38 Ammeter 40 Raw material feeder 41 Primary grinding ball mill 42 Pre-cleaning akins 43 Secondary grinding ore vibro mill 44 Washing device 45 Pickling device 46 Secondary cleaning akins 47 Flash dryer 48 Vibrating sieve 49 First settling tank 50 Screw conveyor 5 Second sedimentation tank 52 Screw conveyor 53 Spiral body (screw) 54 Spiral body (screw) 55 Water supply pipe 56 Acid liquid supply pipe 57 Water outlet 58 Acid liquid inlet 59 Outlet 59a Outlet 60 Iron powder collecting equipment 61 Food Part 62 Exhaust system 62a First straight pipe part 62b Second straight pipe part 63 Chimney 64 Wet classifier 64a Thickener 65 Second water spout 65a Second trapped dust outlet 66 Dust treatment tank 67 First water spout 67a First Captured dust outlet 68 Dust sedimentation tank 69 Spiral 69a Tube 70 Screw conveyor 70a Washing water supply device 71 First partition 72 Second partition 73 Third partition 74 Fourth partition 75 Fifth partition 76 Treatment liquid 1 Part outlet 77 Part of processing liquid outlet 78 Processing liquid inlet 79 Circulation pump 80 Processing liquid circulation pipe 81 First Circulating flow control valve 82 Second circulating flow control valve 83 Supply flow control valve 84 Waste liquid supply valve 85 Supply pipe 86 Waste liquid supply valve 87 Supply pipe 88 Treatment liquid outlet 89 Treatment liquid outlet 90 Pump 91 Treatment liquid transfer pipe 92 No. 1 discharge flow control valve 93 Second discharge flow control valve 94 Bottom discharge valve 94a Discharge pipe 95 Iron powder dust supply pipe 110 Etching waste liquid treatment facility 111 Etching waste liquid tank 112 PH adjuster tank 113 Copper removal device 114 Iron powder storage tank 114a Iron powder storage tank 115 First stirring tank 115a Outlet 116 Liquid cyclone 116a Liquid cyclone 117 First Ekins classifier 117a Second
Akins classifier 117b Akins classifier 117e Copper powder 117f Iron powder 118 Screw feeder 118a Screw feeder 119 Second stirring tank 120 Dust sedimentation tank 120a Dust sedimentation tank 121 Cone tank 121a Cone tank 122 Denickelizer 124 Agitation adjustment tank 125 Aggregation Agent tank 126 Circulation pump 127 Pump 127a Pump 127c Treatment liquid transfer pipe 128 Stirring blade 128a Stirring blade 129 Motor 130 First partition 131 Second partition 132 Third partition 133 Fourth partition 134 Fifth partition 135 First Circulation flow control valve 136 second circulation flow control valve 138 first discharge flow control valve 139 second discharge flow control valve 142 waste liquid supply valve 143 supply flow control valve 145 partial treatment liquid outlet 145 Part of processing liquid outlet 145b Processing liquid inlet 145d Processing liquid circulation pipe 145e Processing liquid outlet 145f Processing liquid outlet 146 Bottom discharge valve 146a Discharge pipe 147 Supply pipe for copper removal processing liquid 150 Third stirring tank 151 First Partition section 152 Second partition section 153 Third partition section 154 Fluid supply section 155 Partition board 156 Nozzle 157 Extraction port 158 Circulation pump 159 Supply port 160 Supply port 161 Discharge port

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Hiroyuki Matsumoto, Inventor 1-3-1 Otani, Yawatahigashi-ku, Kitakyushu-shi, Fukuoka Prefecture Astec Irieuchi Co., Ltd. No.3-1 Astec Irie, Inc. (72) Hiroshi Yoshino, Inventor Hiroshi Yoshino 1-3-1, Oya, Yawata-Higashi-ku, Kitakyushu-shi, Fukuoka Prefecture 1-3-1 Otani Astec Irie, Inc. (72) Inventor Katsumasa Mito 1-3-1, Otani, Yawatahigashi-ku, Kitakyushu-shi, Fukuoka Prefecture Astec Irie, Inc.

Claims (11)

[Claims] 1. An iron powder is mixed into an iron chloride waste liquid containing a metal ion having a smaller ionization tendency than iron such as copper and nickel in a stirring tank, and the iron powder is reacted with the metal ion.
In the method for regenerating an iron chloride-based etching waste liquid that oxidizes the iron powder treatment liquid after the metal ions are precipitated and removed, the iron chloride-based waste liquid is supplied to the stirring tank, and the iron is removed from the upper part of the stirring tank. The iron powder treatment liquid after reacting the powder is taken out and circulated and supplied to the bottom of the stirring tank to form a fluidized bed in which the iron powder is dispersed and floated. A method for regenerating an iron chloride etching waste liquid, comprising taking out the iron powder treatment liquid. 2. The method for regenerating an iron chloride-based etching waste liquid according to claim 1, wherein the iron chloride-based waste liquid is supplied from the bottom of the stirring tank to promote formation of the fluidized bed. 3. An iron powder separating section at an upper portion of the stirring tank, the diameter of which is larger than that of the fluidized bed forming section where the fluidized bed is formed, the flow velocity of the rising liquid is reduced, and the rising of the dispersed and floating iron powder is suppressed. The method for regenerating an iron chloride-based etching waste liquid according to claim 1 or 2, further comprising: 4. The iron chloride waste liquid to be put into the stirring tank is a reduced iron chloride aqueous solution obtained by reducing a part or most of ferric ions to ferrous ions by electrolysis of an iron chloride etching waste liquid. The method for regenerating an iron chloride-based etching waste liquid according to claim 1. 5. The iron chloride etching waste liquid according to claim 4, wherein an electrolytic voltage of the iron chloride etching waste liquid in the electrolysis treatment is controlled within a range of 1 to 4.5 V and a current density is within a range of ² to 40 A / dm ^2. How to play. 6. The method according to claim 4, wherein the distance between the anode plate and the cathode plate of the electrolysis tank in the electrolysis treatment is 1.5 to 50 mm. 7. An electrolysis tank for performing the electrolysis treatment,
An anode chamber provided with an anode and a cathode chamber provided with a cathode are separated by a liquid-permeable membrane, and the iron chloride-based etching waste liquid is supplied from a part of the cathode chamber, and reduced through the cathode chamber. The method for regenerating an iron chloride-based etching waste liquid according to any one of claims 4 to 6, wherein the aqueous solution of reduced iron chloride to be used is taken out from the other part of the cathode chamber. 8. The residual second iron chloride in the aqueous solution of reduced iron chloride.
The method for regenerating an iron chloride-based etching waste liquid according to any one of claims 4 to 7, wherein the concentration of iron ions is 10 to 120 g / liter. 9. The iron chloride according to claim 4, wherein a part or all of the chlorine gas generated from the anode in the electrolysis treatment is used for the oxidation treatment of the iron powder treatment liquid. Method of recycling system etching waste liquid. 10. The method according to claim 1, wherein the iron powder is Ca generated from a steelmaking furnace.
Iron powder dust is recovered from dust containing impurities such as O by a wet method, and the iron powder dust is pulverized, washed with water to remove the impurities, and further pickled to obtain a purified iron powder. The method for regenerating an iron chloride-based etching waste liquid according to any one of the preceding claims. 11. The pickling of the iron dust is performed in a process in which the dust is gradually discharged by a screw conveyor having an acid liquid inlet provided at an upper part thereof, which is inclinedly disposed in a settling tank for storing the iron dust. A method for regenerating an iron chloride-based etching waste liquid according to claim 10.