KR100325981B1 - Method for regenerating a waste solution of iron chloride-based etching solution - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION [0001] The present invention relates to a method for regenerating a ferric chloride-

2. Technical Challenges to be Solved by the Invention

It is possible to efficiently reduce a larger amount of the etching waste liquid with a smaller amount of power by using the iron powder obtained by washing the dust generated from the steelmaking furnace, A method of regenerating a waste solution of a ferric chloride-based etching solution capable of reducing and recovering metal ions having a small tendency (hereinafter referred to as " impurity metal ions ").

3. The point of the solution of the invention

A ferric chloride etchant solution which contains impurity metal ions having a smaller ionization tendency than iron such as copper and nickel and which is mixed with iron chloride as iron powder to react the iron powder with metal ions to remove impurity metal ions, Method. The iron chloride-based etching waste liquid 11 or the iron chloride waste liquid 17 as the intermediate treatment liquid is supplied from the bottom of the stirring tank 18 for holding the iron powder and the iron chloride- (19) is taken out and circulated to the bottom of the agitating tank (18) to form a flow bottom to obtain an iron processing liquid (19) from which metal ions having a lower ionization tendency than iron are removed.

4. Important Uses of the Invention

It is used to regenerate the chloride-based etching waste liquid which is generated when the lead frame for IC, LSI, or shadow mask of cathode ray tube is etched.

Description

Method for regenerating a waste solution of iron chloride-based etching solution

The present invention eliminates metal ions (e.g., copper, nickel) having a low ionization tendency from iron chloride-based etching waste liquid generated when a lead frame for an IC or an LSI or a shadow mask of a cathode ray tube is etched, The present invention relates to a method of regenerating a waste solution of a ferric chloride-based etching solution.

Conventionally, a lead frame or a shadow mask for an IC or an LSI uses, for example, a plate material made of copper, an iron-nickel alloy material or the like. These plate materials are partially etched with an etching solution containing a large amount of ferric chloride . In the etching solution, the ferric chloride contained in the etching solution is reduced to ferrous chloride, and the concentration of the ferric chloride is lowered to deteriorate the etching efficiency, so that the etching solution is periodically exchanged. The etching waste solution, which is a waste solution after the etching treatment, contains a considerable amount of copper ions and nickel ions in addition to a high concentration of iron ions. Further, by removing these metal ions from the etching waste solution, an etchant which can be reused can be obtained.

For example, Japanese Unexamined Patent Publication No. 1-167235 discloses a method in which iron particles or iron particles are added to an etching waste solution to reduce metal ions (for example, copper ions, nickel ions) having a lower ionization tendency than iron in the etching waste solution , Copper and nickel in the waste liquid are recovered and the etchant is regenerated. However, in the method described in this publication, there is a problem that the copper or nickel to be recovered is low and the reaction rate with the etching waste liquid is slow when the iron piece is used for the reaction.

Japanese Unexamined Patent Publication No. 6-127946 discloses a method of adding iron to a ferric chloride-based strong acid waste liquid containing copper, nickel and a small amount of chromium to control the oxidation-reduction potential (ORP) and the iron ion concentration, Iron-based etching waste solution for separating and precipitating copper and nickel ions in this order, and separating and removing suspended impurities such as ferric hydroxide from the thus produced purified iron chloride solution.

However, in the method described in Japanese Patent Application Laid-Open No. 6-127946, metal ion reduction work is carried out by providing a stirring blade in a stirring tank and rotating the stirring blade by a motor to perform stirring. There is a problem as shown in (1) to (5) of FIG.

(1) In the case of treating the etching waste liquid, it is indispensable condition to keep the etching waste liquid in the stirring tank in a good flow state and to maintain a large amount of iron powder in a dispersed state. However, in a mechanical stirring reaction tank such as a stirring wing system, (For example, a large motor that rotates a large agitating blade becomes a very large liquid) is not suitable for a large amount of the etching waste solution to be kept in a dispersed state in the etching waste liquid.

(2) In order to massively or uniformly disperse the 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 blade, and the operation cost is increased.

(3) Since the iron powder is stirred at a high speed by the stirring blade, the iron powder contacts the inner wall of the stirring tank and the stirring blade, and the wear amount of each iron powder is increased, so that the maintenance cost of the stirring tank is increased.

(4) Since the iron particles stay in the corners of the agitating tank, dead spaces can not sufficiently stir the iron particles and the etching waste solution, and the stirring efficiency is lowered and the treatment required for removing metal ions having a lower ionization tendency than iron in the etching waste liquid The time is longer.

(5) It is known that, in a stirring tank for stirring agitation by using a stirring blade, it is possible to relatively easily maintain a favorable suspended state of flow by using iron particles having a small particle diameter. However, the cost of raw materials for such special sizes of iron is high.

In addition, when the etching waste solution is put in a stirring tank and the impurity metal is to be reduced and removed by using iron powder, if a ferric chloride ion is present, a reduction reaction of iron (II) chloride is first carried out to consume iron powder, The total amount of the ferrous ions and the ferric ions in the etching waste solution increases and it is necessary to finally dilute the etchant in order to use the etchant with a predetermined concentration so that a large amount of etchant is generated more than necessary, And a problem with the treatment of surplus etching solution which is not used when all of the generated etching solution is not used.

On the other hand, for example, there is a method described in Japanese Patent Publication No. 57-44724 as a method for producing iron powder which can be used for the above-mentioned method for treating an etching waste solution. This method comprises the following four steps.

That is, in the first step, the dust generated in the pure oxygen frying furnace steel hearth furnace is recovered by a wet method, and the dust is classified to make particles having a size of 44 m or less at 30% or less, Then, in the second step, the coarse particle dust is removed by a wet pulverizer to remove impurities such as scale and sludge, and in the third step, impurities are removed from the dust after the separation to obtain metallic iron. In the fourth step , And this iron is refined to extract iron powder.

However, in the method for producing iron powder described in Japanese Patent Publication No. 57-44724, since the step of removing impurities from dust to obtain iron powder is carried out by classification, thin-flow election, or magnetic electrification, There is a problem that the treatment capacity of the dust is low and mass processing is difficult. Further, in the step of refining metal iron, there is a problem that cost is increased because the treatment is performed in combination with refining treatment by iron oxide refining or leaching reflux.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of efficiently reducing a larger amount of etching waste solution with less power by using iron powder obtained by washing dust produced from a steelmaking furnace, There is provided a method of regenerating a ferric chloride-based etching waste solution capable of reducing and recovering metal ions (hereinafter sometimes referred to as " impurity metal ions ") having a low ionization tendency from iron such as copper or nickel in a ferric chloride- The purpose.

In addition, it is possible to reduce the surplus of the etchant generated when the iron powder is added to the etching waste solution and the metals such as copper and nickel are reduced and finally the ferric iron is set to a predetermined concentration, It is another object of the present invention to provide a method of regenerating a waste solution of a ferric chloride-based etching solution.

FIG. 1 is a conceptual constitutional explanatory view of a waste liquid treatment facility to which a method for recovering a ferric chloride-based etching waste liquid according to the first embodiment of the present invention is applied;

Fig. 2 is an explanatory diagram of the electrolytic apparatus of the waste liquid disposal facility,

FIGS. 3 to 7 are schematic views showing a plurality of patterns of the supply position of the iron chloride-based etchant waste solution in the electrolytic apparatus and the arrangement of the takeout position of the reduced aqueous iron chloride solution,

Fig. 8 is a configuration explanatory view of an iron refining facility of the waste liquid treatment facility; Fig.

FIG. 9 is a side cross-sectional view of a water washing apparatus and an acid washing apparatus in an iron refining facility;

10 is a cross-sectional view taken along line I-I of FIG. 9,

FIG. 11 is a layout diagram of an iron collection facility for obtaining iron dust;

12 is an explanatory diagram of a stirring tank of the waste liquid treatment facility;

13 (a), 13 (b) and 13 (c) are time-dependent graphs of the electrolytic voltage, current density and ferric ion concentration in the electrolytic apparatus,

14 (a), 14 (b), 14 (c) and 14 (d) are schematic diagrams showing transition of the ion concentration in the regeneration treatment of the iron chloride-

15 is a graph showing changes in the CaO concentration of iron dust,

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

FIG. 17 is a cross-sectional view of a second agitation tank used in the same facility,

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

19 is a view seen in the direction of the arrows taken along line II-II in FIG. 18. FIG.

Description of the Related Art

10: waste liquid treatment facility 11: iron chloride-based etching waste liquid

12: electrolytic device 13: converter

14: iron powder Dust 15: refined iron

16: iron refining facility 17: reduced iron chloride aqueous solution

18: stirring tank 19: iron powder

20: etching solution 21: chlorine treatment device

23: anode plate (anode) 24: cathode plate (cathode)

25: liquid inlet 26: liquid outlet

27, 34 to 37, 37a: electrolysis tank 28:

29: control unit 30: diaphragm

31: anode chamber 32: cathode chamber

33: outlet 40: raw feeder

41: primary grinding light ball mill 42: preliminary cleaning Ekinz

43: Secondary polishing light vibro 44: Water cleaning device

45: Acid cleaning device 46: Second cleaning Etkinz

47: Air dryer 48: Vibrating sieve

49: first settling tank 50,52: screw conveyor

51: second settling tank 53, 54:

55: water supply pipe 56: acid solution supply pipe

57: Water outlet 58: Acid inlet

59, 59a: outlet 60: iron collection facility

61: hood part 62: exhaust system

62a: first straight pipe portion 62b: second straight pipe portion

63: communication 64: wet classifier

64a: Sikner 65: Second water outlet

65a: Second capturing dust outlet 66: Dust treating tank

67: first water outlet 67a: outlet

68: Dust settling tank 69a: Tubular body

70: screw conveyor 70a: washing water supply device

71-75: first to fifth compartments

76,77 part of the treatment liquid outlet 78: treatment liquid inlet

79: circulation pump 80: treatment liquid circulation pipe

81,82: Circulating flow control valve 83: Supply flow control valve

84: Waste liquid supply valve 85: Supply piping

86: waste liquid supply valve 87: supply pipe

88, 89: Process liquid outlet 90: Pump

91: Process liquid transfer pipe 92: First discharge flow control valve

93: Second discharge flow control valve 94: Bottom discharge valve

94a: outlet pipe 95: iron dust pipe

110: etching waste solution treatment facility 111: etching waste solution tank

112: pH adjuster tank 113:

114, 114a: iron storage tank 115: first stirring tank

115a: outlet 116, 116a: liquid cyclone

117: first Ekinch classifier 117a: second Ekinch classifier

118, 118a: screw feeder 119: second stirring tank

120, 120a: Dust settling tank 121, 121a: Cone tank (inverted conical tank)

122: Nickel unit 124: stirring tank

125: coagulant tank 126: circulation pump

127,127a: Pump l27c: Process liquid transfer pipe

128, 128a: stirring blade 129: motor

130 to 134: first to fifth compartments

135: first circulating flow control valve 136: second circulating 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, 145a: Process liquid partial outlet 145e, 145f: Process liquid outlet

145b: treatment liquid inlet port l45d: treatment liquid circulation pipe

146: bottom discharge valve l46a: discharge pipe

147: Supply piping 150: Third stirring tank

151 to 153: first to third compartments

154: liquid supply unit 155: partition plate

156: nozzle 157: outlet

158: circulation pump 159: supply port

160: Deviation treatment liquid is supplied from the supply port 161:

1A: iron mixture liquid 1B:

2A: slurry 2B: primary iron treatment liquid

2C: De-nickel treatment liquid 2D:

2E: iron processing solution 2F: secondary iron processing solution

3A: Iron processing liquid 3B: Iron processing liquid

C: concentration of ferric ion D: current density

E: Electrolytic voltage L: Inter-pole distance

P: Pump Q: Supply flow

S: Effective area

According to the present invention, there is provided a method for regenerating a ferric chloride-based etching waste liquid comprising mixing an iron chloride into an iron chloride-based waste liquid containing metal ions having a lower ionization tendency than iron such as copper and nickel in a stirring tank, A method of regenerating a ferric chloride-based etching waste solution which comprises reacting metal ions to precipitate and control the metal ions, and oxidizing the iron-containing solution, characterized in that the ferric chloride-based waste solution is supplied to the stirring tank, The iron treatment liquid after the reaction of the iron powder is taken out and circulated to the bottom of the stirring tank to form a floating bottom floated with the iron powder dispersed to extract the surplus iron treatment liquid from the upper part of the stirring tank .

In the method of regenerating the iron chloride-based etching waste solution according to the present invention, the iron-containing liquid having the impurity metal ions removed from the upper portion of the stirring tank is taken out and circulated to the bottom portion of the stirring tank to form a flowing bottom. In an appropriate range can be treated only with the iron processing solution. Therefore, even when the supplied iron chloride-based waste liquid fluctuates, the flow bottom can be stably formed, and as a result, the reaction between the iron chloride-based waste liquid and the iron powder can be performed in a stable state. In addition, since a part of the iron-containing processing liquid is taken out from the upper part of the stirring tank and supplied from the bottom part, a flowing bottom can be formed without generating a dead space which does not contribute to the reaction in the stirring tank, The removal efficiency of the impurity metal ions in the waste liquid can be enhanced.

In the method for regenerating the iron chloride-based etching waste solution according to the present invention, it is preferable that the iron chloride-based waste solution is supplied from the bottom portion of the stirring tank to promote the formation of the flowing bottom, The contact speed of the iron can be increased to increase the processing speed.

Further, in the method for regenerating a waste solution of a ferric chloride-based etching solution according to the present invention, the diameter of the flow-bottom forming portion in which the flow bottom is formed is enlarged in the upper portion of the stirring tank to slow the flow rate of the ascension fluid, It is preferable to provide an iron separator for suppressing the rise of the iron powder. Thus, even when the ascending flow of the fluid in the stirring tank is decelerated by the iron separating section, the iron content of about the predetermined particle or more does not float to the iron separating section, and the flow rate in the stirring tank fluctuates somewhat, And it is possible to remove the impurity metal ions under a stable condition.

In the method for regenerating the iron chloride-based etching waste solution according to the above invention, the iron chloride-based waste solution to be supplied to the stirring tank is a solution of the iron chloride-based etching waste solution which is previously subjected to electrolytic treatment to a part or almost all of the iron It is preferable to use a reduced aqueous solution of iron chloride reduced to iron ion, and the reason is as follows. Even if the ferric chloride-based etching waste solution is reduced to ferrous iron by ferrous ion by the electrolytic treatment as described above, the total ferric ion concentration of the ferrous iron and ferric ion does not change. Therefore, at the time of the regeneration treatment of the ferric chloride-based waste solution in which the ferrous ion is subjected to the oxidation treatment (for example, by sucking the chlorine gas) in the final step, the amount of iron powder does not change, Is not increased to a surplus. That is, when the iron is used only in the conventional manner, the reaction of the iron contained in the ferric ion and the reaction of the ferrous iron to the ferrous iron occurs. As a result, the amount of the iron contained is increased more than necessary, Surplus water is generated when the ferrous iron is oxidized, but in the present invention, since the ferrous iron is reduced to ferrous iron without using iron powder, the generation of the 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 used in the regeneration treatment of the iron chloride-based waste solution can be reduced, the treatment cost can be reduced.

Here, the average electrolytic voltage of the ferric chloride-based etching waste solution in the electrolytic treatment is 1 to 4.5 V (more preferably 1.5 to 3 V) and the current density is ² to 40 A / dm ² (more preferably, 20 A / dm < ² >). Thereby, the electrolytic voltage and the current density in the electrolytic treatment are controlled in a specific range. Therefore, it is possible to maintain the necessary reducing effect without precipitating impurity metal ions such as copper and nickel contained in the iron chloride waste solution, The waste liquid can be regenerated. Further, when the electrolytic voltage is lower than 1 V, the ferric ion is substantially lower than the theoretical electrolytic voltage for reducing the ferrous ion to the ferric ion, so that the reducing effect can not be obtained. Conversely, if the electrolytic voltage exceeds 4.5 V, copper, nickel, or the like contained in the waste solution of the ferric chloride-based etching solution precipitates impurity metal ions, which is not preferable. When the current density is lower than ^{2 A} / dm ² , the treatment capacity of the ferric chloride-based waste solution is lowered. Therefore, it is necessary to increase the size of the facility to treat a predetermined amount of the liquid. If the current density exceeds 40 A / dm ² , the electrolytic voltage increases and the power cost rises, which is not economical. Further, the load on the electrode is increased, the lifetime is reduced, and precipitation of the impurity metal ions is promoted, which is not preferable.

The distance between the positive and negative electrode plates of the electrolytic bath in the electrolytic treatment is preferably 1.5 to 50 mm. With this configuration, since the distance between the positive and negative electrode plates in the electrolytic bath is set to a specific range, the intrusion of chlorine gas generated in the positive electrode plate into the negative electrode portion can be suppressed, and oxidation of the ferrous ion can be inhibited , An increase in electrolytic voltage can be suppressed. Here, when the gap distance becomes shorter than 1.5mm, it becomes easy by the chlorine gas generated on the positive electrode plate passes through the membrane to break into parts of the cathode, the oxide is first iron ions herein _{(FeCl 2 + (1/2) Cl} 2 → FeCl ₃ ). In addition, since supply of the liquid to the electrode surface is substantially difficult, metals such as copper and nickel are liable to be precipitated. If the inter-electrode distance exceeds 50 mm, the electrolytic voltage increases and the electric power cost rises, which is not preferable. More preferably, the inter-pole distance is in the range of 2 to 20 mm.

Then, the electrolytic bath performing the electrolytic treatment is partitioned into a cathode chamber having a cathode and a cathode chamber having a cathode by a liquid-permeable diaphragm, and the chloride-based etching solution is supplied from a part of the cathode chamber , And the reduced aqueous solution of iron chloride which is subjected to the reduction treatment through the cathode chamber can be taken out from the other portion of the cathode chamber. As a result, it is possible to prevent the chlorine gas generated in the positive electrode plate from substantially mixing with each other in the supplied iron chloride-based etching waste solution and the reduced aqueous solution of iron chloride, so that efficient electrolysis can be performed.

The concentration of the residual ferric ion in the aqueous solution of reduced iron chloride treated by the electrolytic treatment is preferably 10 to 120 g / l. This is because when the concentration of ferric ion in the aqueous solution of reduced iron chloride is less than 10 g / l, the amount of reduction of the ferric ion to ferrous ion relative to the unit current is reduced, , Nickel ions are precipitated and copper or nickel is generated. When the concentration of ferric ion in the reduced aqueous iron chloride solution exceeds 120 g / l, the ferric ion reacts with iron in the stirring tank , The consumption of iron is increased, and thus surplus etching solution is increased. The concentration of ferric ion in the aqueous solution of reduced iron chloride is preferably in the range of 10 to 120 g / l, more preferably 100 g / l or less in this range.

Here, in the electrolytic treatment, a part or all of the chlorine gas generated from the anode is sucked into the iron treatment liquid taken out from the stirring tank to oxidize a part of the ferrous ion to make the ferric ion . Thereby, it is possible to efficiently perform the regeneration treatment of the iron chloride-based etching waste solution without generating unnecessary by-products.

The iron powder to be used in the present invention is recovered from the dust containing impurities such as CaO generated from the steelmaking furnace by a wet method and the iron powder dust is pulverized and subjected to water cleaning to remove the impurities, It is preferable to use refined iron. Thereby, iron powder generated from the steelmaking furnace can be effectively used, and impurities such as CaO can be reduced in the regenerated etchant.

The pickling of the iron dust can be performed in a process of being gradually inclined to a sedimentation tank for storing the iron dust and gradually discharged by a screw conveyor provided with an acid solution injection port. The iron powder to be used can be produced in large quantities and inexpensively by continuous treatment.

Here, it is preferable that the pH of the oxidation treatment solution of the precipitation tank is adjusted to pH 0.5 to 3. As a result, it is possible to maintain the amount of impurities such as CaO in refined iron powder at a predetermined level, and to manage the cost of the acid solution, the treatment cost, and the maintenance cost in an appropriate range, and to regenerate the iron chloride- . In addition, when the hydrogen ion concentration (pH) of the acid solution is less than 0.5, the corrosiveness of the acid solution becomes serious, and it is necessary to perform a special acid treatment for the facility, and the cost for equipment repair increases. On the other hand, if the hydrogen ion concentration is larger than 3, impurities including scales and sludge adhering to iron powder can not be eluted sufficiently, which is not preferable.

In the method for regenerating the iron chloride-based etching waste solution according to the present invention described above, the iron chloride-based waste solution refers to an etching waste solution containing ferrous chloride (FeCl ₂ ), ferric chloride (FeCl ₃ ) Refers to an aqueous solution of an acid and includes metal ions which tend to have a lower ionization tendency than iron such as copper, nickel, and chromium in the course of etching.

The iron powder is, for example, powdered iron having a particle diameter of 44 to 250 占 퐉, and the shape includes a spherical shape, a porous shape, and the like. However, the reduced iron powder and atomized iron powder can be applied.

The floating bed means a region where the iron powder supplied into the stirring tank is balanced by the magnetic force and the viscous resistance due to the flow supplied from the lower portion and the iron powder density floating in a certain space is high.

The iron-containing treatment liquid is an aqueous solution in which metal ions of impurities such as copper and nickel, which have passed through the flow bottom and are eluted to the upper region thereof, are reduced and removed, and iron powder or solid suspended material not separated in the liquid is dissolved in a small amount, % ≪ / RTI >

The iron separating section refers to a region located above the flowing bottom divided to divide the stirring tank in the up and down direction, but is not a physical partition between the two. Since the horizontal cross-sectional area of the iron separating section is enlarged upward, the flow rate of the aqueous solution of iron chloride supplied from the lower part of the stirring tank lowers and the action of the suspended iron flowing into the iron separating section do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

(Embodiment 1)

First, the constitution of a waste liquid treatment facility 10 to which a method for recovering a ferric chloride-based etching waste solution according to the first embodiment of the present invention is applied will be described with reference to FIGS. 1 to 12.

1, the waste liquid treatment facility 10 includes an electrolytic apparatus 12 for reducing ferric ion in ferric chloride-based etching waste liquid 11 as ferrous iron, An iron refining facility 16 for refining the iron powder 14 taken out from the converter 13 as an example and obtaining refined iron powder 15 and a refined iron chloride aqueous solution 17 and an iron refining solution 16 treated in the electrolytic apparatus 12, A stirring vessel 18 for stirring the purified iron 15 obtained by the facility 16 to precipitate impurity metal from the reduced aqueous iron chloride solution 17 and a stirring vessel 18 for stirring the iron chloride solution 19 And a chlorination device 21 for obtaining an etchant 20 which is oxidized and recovered as iron (II) ions. Hereinafter, the configuration of each device of the waste liquid treatment facility 10 having the above-described configuration will be described.

First, the specific configuration of the electrolytic apparatus 12 will be described in detail with reference to FIGS. 2 to 7.

2, the electrolytic apparatus 12 includes a positive electrode plate (anode) 23 and a negative electrode plate (cathode) 24 maintained at a predetermined interval, An electrolytic bath 27 provided with an electrolytic bath 25 and an outlet 26 of an aqueous solution of reduced iron chloride 17 which has been treated on top of the electrolytic bath 27; Data such as the current density D of the power supply unit 28 and the electrolytic bath 27, the secondary iron ion concentration C in the reduced aqueous iron chloride solution 17, and the amount of chlorine gas generated from the positive electrode plate 23 are input , An electrolysis voltage (E), and a supply flow rate (Q) of the iron chloride etching waste liquid (11).

The electrolytic bath 27 is divided into an anode chamber 31 and a cathode chamber 32 by a diaphragm 30 disposed around the cathode plate 23 and a cathode plate 23 And a chlorine gas outlet 33 for collecting the chlorine gas generated from the chlorine gas outlet 33 is provided. In this embodiment, the feeding position of the iron chloride-based etching waste liquid 11 to the electrolytic bath 27 and the extraction position of the reduced aqueous iron chloride solution 17 treated in the electrolytic bath 27 are as shown in FIG. 2 , The liquid inlet 25 of the iron chloride etchant waste liquid 11 and the liquid outlet 26 of the reduced aqueous iron chloride solution 17 are provided on the cathode chamber 32 side to adopt a pattern to be supplied to the cathode side and taken out on the cathode side Respectively. This makes it less likely that the primary iron ions in the supplied iron chloride-based etching waste solution 11 and the treated reduced iron chloride aqueous solution 17 are oxidized by the chlorine gas generated in the positive electrode plate 23, The iron chloride ions in the iron chloride-based etching waste solution 11 can be rapidly supplied to the surface of the iron chloride-based etching solution.

However, the arrangement of the liquid inlet port 25 of the iron chloride-based etching liquid waste solution 11 and the liquid outlet port 26 of the aqueous solution of reduced iron chloride 17 is the same as that of the electrolytic bath 34 of the pattern shown in FIGS. 37, 37a). The formation positions of the liquid inlet port 25 of the iron chloride-based etching waste liquid 11 and the liquid outlet port 26 of the reduced aqueous iron chloride solution 17 in the electrolytic baths 34 to 37, Therefore, it can be exchanged up and down.

Although the electrolytic baths 27, 34 to 37, and 37a of FIGS. 2 to 7 are conceptually shown as a combination of a pair of the positive electrode plates 23 and the negative electrode plates 24, And a plurality of portions where the anode chamber and the cathode chamber are partitioned by the diaphragm are arranged. In Fig. 7, the positive electrode plate 23 is completely partitioned by the diaphragm 30, and the chlorine gas is discharged from the upper portion. In addition, the present invention is not limited to the electrolytic bath as an example of the second to seventh figures. For example, there is a well-known filter press system and a bus system. In power supply to the electrolytic bath, There is a pole method.

As the positive electrode plate 23, for example, a DSE electrode made of Pelmec Co., Ltd. or a DSA electrode, which is formed by partially covering titanium oxide with ruthenium oxide, is preferably used. Platinum-coated titanium or graphite plate may be used for the positive electrode plate 23 as an electrode, but it is preferable to use a DSE electrode having a low chlorine overvoltage, a high oxygen overvoltage and a low electrical resistance. As the material of the cathode plate 24, it is preferable to use a titanium or nickel alloy having a high hydrogen overvoltage and a small electrical resistance, which is applicable to graphite, titanium, iron, stainless steel, copper, nickel, and nickel alloys. The shape of the positive electrode plate 23 and the negative electrode plate 24 may be a shape such as a so-called expanded metal, a rod shape, a plate shape, a foot shape, or the like, which is obtained by pulling a metal plate having many small gaps.

2, the diaphragm 30 shields chlorine gas generated in the positive electrode plate 23 from the negative electrode chamber 32 and oxidizes the ferrous oxide in the negative electrode chamber 32 (FeCl ₂ + 1/2) Cl _{2 -} > FeCl ₃ ) and collecting chlorine gas. The material of the diaphragm 30 is preferably a material which has liquid permeability but is good in blocking the generated chlorine gas and is inexpensive. Specifically, fibrils and ion exchange resins are suitable, and a filter cloth (trade name: "Pylenfilament PF 4000") manufactured by Izumi Co., Ltd., having a thickness of about 1 mm, was used.

Although the inter-electrode distance L between the positive electrode plate 23 and the negative electrode plate 24 is set to 8 mm in this embodiment, if necessary, the inter-electrode distance L, that is, the inter- It is preferable to set the inter-pole distance L in the range of 2 to 20 mm.

The control unit 29 may be a control unit such as a program controller (sequencer) or the like that inputs a predetermined processing program in advance and performs processing by an input program or the like, ), Electrolytic voltage (E), and the like. The current i supplied to the electrolytic bath 27 is measured by an ammeter 38 provided between the DC power supply 28 and the electrolytic bath 27 And the current density D (= i / S) can be obtained by dividing the current value by the effective area S of the positive electrode plate 23 and the negative electrode plate 24. The metal ion concentration (ferric ion concentration) C in the reduced aqueous iron chloride solution 17 taken out of the electrolytic bath 27 can be continuously or intermittently measured with an ion meter or the like as necessary.

The control unit 29 receives the control data of the current density D and the ferric ion concentration C and outputs the electrolysis voltage E and the ferric chloride etchant waste solution 11 The supply flow rate Q of the fuel gas supply system can be adjusted.

Next, the iron refining facility 16 capable of refining the iron powder 14 extracted from the converter 13 to produce the refined iron powder 15 will be described in detail with reference to FIGS. 8 to 10 do.

8, the iron refining facility 16 includes a raw feeder 40 for the iron powder dust 14, a primary polishing optical ball mill 41, a preliminary cleaning etchant 42, The water cleaning device 44, the acid cleaning device 45, the secondary cleaning etching nozzle 46, the air flow dryer 47, and the vibrating sifter 48 , The refined iron 15 is produced by arranging these devices in series. Further, since the structure of the above-described apparatus excluding the water washing apparatus 44 and the acid washing apparatus 45 is widely known, a detailed description thereof will be omitted. The construction of the water cleaning device 44 and the oxidation device 45 constituting the main part of the iron refining facility 16 will be described below with reference to FIGS. 9 and 10.

As shown in the figure, the water scrubber 44 includes an inverted cone-shaped first settling tank 49 into which the processed product of the iron dust 14 is introduced, a screw 49 for cleaning and discharging the precipitate of the first settling tank 49, Has a conveyor (50).

On the other hand, the acid scrubber 45 has an inverted cone-shaped second settling tank 51 into which the cleaning iron discharged from the upper part of the screw conveyor 50 of the water scrubber 44 is charged and the second settling tank 51, And a screw conveyor 52 for cleaning, classifying, and removing water by piling up the precipitate of the screw conveyor 52.

Each of the screw conveyors 50 and 52 is immersed in a first settling tank 49 and a second settling tank 51 and is inclined at an angle of 10 to 50 degrees with respect to the horizontal direction. , 52 are at least open at their upper part.

The screw conveyors 50 and 52 are provided with screw members 53 and 54 for scraping up and moving up the sediments deposited on the bottom of the first and second settling tanks 49 and 51 Is installed. The precipitates stored in the bottom portions of the first and second settling tanks 49 and 51 are gradually transported upward by the screw conveyors 50 and 52 by rotating the helicoids 53 and 54 with a motor or the like have.

A water supply pipe 55 and an acid solution supply pipe 56 are provided on the upper portions of the helical bodies 53 and 54 of the screw conveyors 50 and 52, respectively. The water outlet 57 is provided in the water supply pipe 55 and the acid solution inlet 58 is provided in the acid solution supply pipe 56 and the cleaning water and the oxidizing solution are supplied to the open portions above the screw conveyors 50 and 52, respectively .

Therefore, the sediment moving upward in the screw conveyors 50 and 52 due to the rotation of the helical bodies 53 and 54, the washing water flowing downward through the gravity of the screw conveyors 50 and 52, The particles having a relatively small particle diameter in the precipitate are washed away and fall down in the screw conveyors 50 and 52 to be accumulated in the first and second settling tanks 49 and 51 and the fine particles are removed And the sediment is discharged from the discharge ports 59, 59a provided on the upper side of the screw conveyors 50, 52 downwardly, respectively. Also, the preliminary cleaning etchants 42 and the secondary cleaning etchants 46 each have a screw conveyor, and have the same structure as the above-described water cleaning apparatus.

The iron dust 14 to be supplied to the iron refining facility 16 from the converter 13 can be collected by the iron collection facility 60 shown in FIG.

As shown in the figure, a hood portion 61 for collecting dust and generated gas generated from the converter 13 is arranged on the upper portion of the converter 13, and the hood portion 61 is provided with an exhaust system 62 Is connected to the end of the exhaust system 62. A communication 63 for discharging the harmless gas into the atmosphere is connected to the end of the exhaust system 62 by the dust collecting operation described later.

A first water jet opening 67 and a first acquisition dust outlet 67a are provided at the upper and lower ends of the first straight pipe portion 62a on the upstream side of the exhaust system 62, respectively. Water is jetted from the first water jetting port 67 into the first straight pipe portion 62a and brought into contact with the generated gas flowing in the exhaust system 62 and the dust containing the iron powder in the generated gas is almost %). Then, the trapped dust is fed to the wet classifier 64, which will be described later, through the first trapping dust outlet 67a while being mixed with the jetting water.

11, a second straight pipe portion 62b is connected to the downstream side of the first straight pipe portion 62a through a horizontal end portion, and a second water pipe 65 (65) is provided at the upper end and the lower portion, And a second trapping dust outlet 65a are provided. Water is jetted from the second water spouting port 65 into the second straight pipe portion 62b to come into contact with the generated gas flowing in the exhaust system 62 to substantially capture the remaining dust (5%) contained in the generated gas . Then, the number of injected dust mixed with dust is sent to the dust-treating tank 66 through the second trapping dust outlet 65a. Since this jetting number contains only a small amount of dust, it is possible to effectively use the jetting water for jetting from the first water jetting port 67 into the first straight pipe portion 62a by using the pump P have.

The wet classifier 64 has a dust settling tank 68. The dust settling tank 68 is provided with a dust containing iron powder discharged from the first straight pipe portion 62a, It is supplied with water. Then, only the dust including the iron powder is precipitated as sediment dust (D) at the bottom of the dust sedimentation tank (68).

A screw conveyor 70 composed of a long tubular body 69a and a helical body 69 rotating in the tubular body 69a is arranged in the dust sedimentation tank 68. The starting end of the screw conveyor 70 is connected to a dust sedimentation tank 68, and the end thereof protrudes upward from the upper edge of the dust sedimentation tank 68. At the end of the screw conveyor 70, a cleaning water supply device 70a is arranged.

Accordingly, in the wet classifier 64, the washing water or the like is supplied from the end side of the screw conveyor 70, whereby the fine particles in the precipitate selectively descend along the inner wall of the screw conveyor 70, The precipitate (iron dust) having relatively large particle size in the precipitate and excess moisture removed can be taken out from the top of the screw conveyor 70. [

Further, in this embodiment, the upper clear liquid on the upper part of the dust settling tank 68 is fed to the Sikner 64a installed side-by-side to precipitate and remove minute components (such as iron oxide) in the clean liquid on the far side to make clean water, Is used as water for jetting from the second water jetting port (65) into the second straight pipe portion (62b). Thus, by using the water circulation, it is possible to reduce the cost required for the iron-harvesting work.

The first and second water outlets 67 and 65 of the exhaust system 62 are tightened at the front end of the iron particle collection facility 60. By this tightening structure, When inhaled, mixing of the exhaust gas or the dust with the water is effectively performed, and the dust captured by the water can be effectively captured.

Next, with reference to FIG. 12, the construction of the stirring tank 18 for stirring the reduced iron oxide aqueous solution 17 and the purified iron powder 15 to precipitate the impurity metal from the reduced iron oxide aqueous solution 17 will be described.

As shown in the figure, the agitating tank 18 has a volume of 17 m ³ composed of five regions of the first to seventh compartments (71 to 75) configured to have different horizontal cross-sectional areas in the vertical direction, About 3.2 m, and the refined iron 15 for treating the iron chloride-based waste solution can be maintained at, for example, about 21 tons.

The first partition 71, which is the uppermost portion of the agitating tank 18, is an area made up of a straight portion having a maximum cross-sectional area in the horizontal direction. The upper end opening of the first partition 71 is open to the atmosphere. So that the refined iron powder 15 can be supplied. On the other hand, the second dividing section 72 following the first dividing section 71 is an area made of a tapered section whose diameter gradually decreases toward the downward direction. An iron separator (freeboard) is formed by these first and second compartments 71 and 72, and the flow rate of the ascending flow is made slower, It is possible to prevent the iron particles in the floating flow state, that is, the dispersed floating state, from rising and entering the iron separation portion.

On the other hand, in the lower portion of the second partition 72, a third partition 73 having the same cross-sectional area as the lower end of the second partition 72 is formed, and the third partition 73 And a fifth compartment 75 consisting of a small-diameter straight portion is provided in series at the lower end of the fourth compartment 74 . In the third to fifth partitioning parts 73 to 75, the iron floated high-density floating float which can keep the iron powder in a floating flow state by the circulating flow mainly composed of the reduced iron chloride aqueous solution 17, As shown by hatching in Fig.

The first and second partition sections 71 and 72 forming the iron separation section are respectively provided with treatment liquid part extraction ports 76 and 77 and the fifth part A treatment liquid inlet 78 is provided in a side wall of the partition 75.

The process liquid inlet ports 76 and 77 and the process liquid inlet port 78 are connected to each other through a process liquid circulation pipe 80 having a circulation pump 79 in between. Therefore, by driving the circulation pump 79, the amounts of the iron content in the first and second compartments 71 and 72 are extremely small, The iron processing liquid 19 is introduced into the fifth compartment 75 through the processing liquid circulating pipe 80 and the processing liquid inlet port 78. Thereby, And a self-circulating flow is formed in the stirring tank 18.

The upper end of the treatment liquid circulating pipe 80 is provided with a treatment liquid circulating pipe 80 for controlling the flow rate of the iron liquor treating liquid 19 passing through the treatment liquid circulating pipe 80 through the two treatment liquid part outlet ports 76, 1 and second circulating flow control valves 81 and 82 are provided in the lower portion of the process liquid circulating pipe 80. A supply flow rate control valve 83 is provided at the lower end of the process liquid circulating pipe 80. [ By using the first and second circulation flow rate control valves 81 and 82 and the supply flow rate control valve 83, the flow rate of the circulating liquid can be easily controlled. Therefore, the agitating tank 18 is supplied through the supply pipe 85 of the reduced iron chloride aqueous solution 17 (and in some cases, the iron chloride etch waste liquid) provided with the waste liquid supply valve 84 on the way and the treatment liquid inlet 78, Irrespective of the amount of the reduced iron chloride aqueous solution 17 (in some cases, the iron chloride-based etching waste liquid) supplied into the stirring tank 18, the flow state of the refined iron 15 supplied to the stirring tank 18 by the circulation system is set in an appropriate range So as to form a flow bottom.

It is also possible to roll up the iron powder or the like by discharging a part of the iron processing liquid 19 to the fifth compartment 75 made of a small-diameter straight portion which is liable to precipitate iron, The generation of the dead space of the memory is suppressed.

The reduced iron chloride aqueous solution 17 (and in some cases the ferric chloride-based etchant waste liquid 11 may be supplied to the piping between the supply flow rate control valve 83 and the circulation pump 79 with a waste liquid supply valve 86 Is supplied to the agitating tank 18 through the supply pipe 87 or through the supply pipe 85 to the first compartment 71. [

The first partition 71 forming the iron separating portion and the side wall of the second partition 72 are provided with the treatment liquid outlet ports 88 and 89 in addition to the treatment liquid partial outlet ports 76 and 77 And a process liquid transfer pipe 91 having a pump 90 is connected to the process liquid discharge ports 88 and 89 in the middle. On the other hand, the outlet side of the process liquid transfer pipe 91 is connected to the chlorination device 21 in succession. The iron processing liquid 19 obtained by being processed in the stirring tank 18 is sent to the chlorination apparatus 21 or the like through the processing liquid transfer pipe 91 by driving the pump 90 .

The flow rates of the iron-containing liquid 19 discharged from the treatment liquid discharge ports 88 and 89 are set such that the flow rate of the iron-containing liquid 19 discharged from the treatment liquid discharge ports 88, The flow rate control valve 92 and the second discharge flow rate control valve 93. [

As described above, since the iron-containing liquid 19 can be selected as required from the reaction dividing sections having different treatment arrangements, or the iron-containing liquid 19 having different characteristics can be taken out from each of the dividing sections, The iron ion concentration in the iron ion treatment liquid 19 transported by the iron ion treatment liquid 19 and the like can be controlled so that the waste liquid treatment described below can be controlled to an appropriate condition.

When the refined iron powder 15 in the stirring tank 18 is insufficient, the refined iron powder 15 is supplied from the upper portion of the agitation tank 18. The bottom of the agitating tank 18 is provided with a discharge pipe 94a provided with a bottom discharge valve 94 for discharging the solid substances settled in the bottom portion, have.

Next, the configuration of the chlorination apparatus 21 for obtaining the regenerated etching solution 20 by oxidizing the ferrous ion in the iron-containing liquid 19 taken out from the agitating tank 18 and using ferric ion is described .

Although not shown, the chlorine treatment device 21 needs to keep the highly corrosive iron-containing liquid 19 in a stored state, and therefore it is preferable that the chlorine treatment device 21 is made of a material having high corrosion resistance such as FRP (fiber reinforced plastic) It consists of a container. The chlorine gas generated by the electrolytic device 12 or the like is sucked or bubbled into the iron-containing liquid 19 treated in the stirring tank 18 so that the ferrous iron in the iron- The regenerated etchant 20 can be obtained by oxidizing part or the whole of the ferric iron.

The chlorination reaction may be carried out by, for example, a primary chlorination process and a secondary chlorination process, whereby the reaction efficiency with chlorine can be increased again.

Next, the process of the method for recovering the iron chloride-based etching waste liquid according to the first embodiment of the present invention by the waste liquid treatment facility 10 having the above-described structure will be described in detail.

First, a method of producing purified iron powder 15 by purifying the iron dust 14 collected from the converter 13 by using the iron refining equipment 16 shown in FIG. 8 and FIG. 9 will be described.

The iron powder dust 14 containing moisture discharged from the wet classifier 64 of FIG. 11 is supplied to the primary molten iron ball mill 41 using the raw material feeder 40 as shown in FIGS. 8 to 10 ). The primary abrasive ball mill 41 is a substantially cylindrical ball mill capable of processing the iron dust 14 continuously fed by the feed material feeder 40. The number of revolutions of the ball mill is 20 to 36 rpm, The quantity is 3-5 tons.

The supply amount of the water containing the iron dust 14 to be sent to the primary polishing ball mill 41 is 200 to 1000 l / hr (average: 270 l / hr) and the concentration of the iron powder dust 14 is 50 to 1000 l / 80 wt% (average: 65 wt%).

The retention time or the processing time of the iron powder 14 in the primary polished ball mill 41 is about 60 to 120 minutes. By this grinding treatment, a part of the impurities contained in the iron powder dust 14 is removed from the iron powder So that it can be peeled off.

The reason why the wet grinding treatment is performed as described above is that the dust itself recovered from the converter 13 is a wet powder containing a large amount of moisture as described above and is dried as a pretreatment to be dry treated A process is required and the subsequent oxidation treatment itself is carried out in a wet manner, so that a drying treatment is required again after the oxidation treatment, which makes it economical. In addition, dusting is more likely to occur when the pulverization treatment is carried out by a dry method, which requires measures against dust, and it is not preferable because cost for environmental measures is generated.

The processed product of the iron dust 14 discharged from the primary polishing ball mill 41 is peeled off from the iron powder over the preliminary cleaning etchant 42 having the same constitution as the wet classifier 64 shown in FIG. The impurities are washed and flowed. Here, the velocity of the fluid overflowing in the precipitation tank of the preliminary cleaning etchers 42 is 3 to 10 m / hl (average: 5 m / hr), and the feed rate of the washing water Is ³ to 25 m ³ / hr (average: 5 m ³ / hr). Part of the impurities released from the iron powder in the processed product are further separated and removed by the cleaning treatment using the preliminary washing etchant 42 and the minute portions in the iron powder are removed at the same time, The particle diameter can be shifted in the direction of increasing the particle diameter.

Next, the processed material discharged from the preliminary cleaning etchant 42 is pulverized through the second abrasive light vibro-mill 43. The amount of water containing the iron dust 14 is 200 to 1000 l / hr (average: 270 l / hr), and the amount of water containing the iron dust 14 is 20 to 1000 l / (Average: 65 wt%) was 50 to 80 wt%. By the pulverizing treatment using the secondary polishing optical vibro-mill 43, the impurities remaining on the iron powder in the mixture are further finely pulverized, and the iron powder (iron powder) in which the separation efficiency between the iron powder and the impurities in the following steps is increased 14) can be obtained.

15 shows the change in the concentration of CaO, which is an example of the impurities in the treated product containing iron powder. In Fig. 15, 2 to 7 wt % Is reduced in the range of 0.5 to 5 wt% after the cleaning of the primary polishing light by the preliminary cleaning etchant 42 (Fig. 15 (B)).

However, since a large amount of impurities remain in the treated product of the iron dust 14 as such, the purity is not sufficient as a reducing agent when it is used for the regeneration treatment of the iron chloride waste solution and can not be used in this state . Therefore, it is necessary to further perform the cleaning classification processing of the iron dust 14 by using the water cleaning device 44 and the oxidation device 45 as shown in FIG. 9 and FIG. 10.

Thus, the treated product of the iron dust 14 is introduced into the first settling tank 49 from the upper part of the water washing device 44 through the iron dust supply pipe 95. As a result, iron particles having large particle diameters in the iron dust 14 are precipitated one after another to form a layer of precipitate at the bottom of the first settling tank 49. Then, the helical body 53 disposed in the screw conveyor 50 is rotated by a driving device such as a motor.

At this time, the washing water is supplied at an average rate of ³ to 25 m ³ / hr from the water outlet 57 of the water supply pipe 55, a descending flow by the washing water is formed in the screw conveyor 50, Since the treated product of the iron dust 14 is supplied from the iron dust supply pipe 95 into the settling tank 49 as described above, an overflow having a relatively small specific gravity as a whole including fine iron powder and dust is generated. When the rising rate of the overflow is adjusted to a range of 3 to 10 m / hr (average: 5 m / hr), the iron dust 14 is separated and purified.

By the above operation, the fine powder portion in the iron powder dust 14 is washed out as an overflow, and the coarse grain portion is selectively discharged from the top of the screw conveyor 50 as the cleaning iron powder. Since the plaque of the impurity is removed, the impurity (CaO) in the iron dust 14 is reduced to 0.3 to 1.7 (as shown in FIG. 15 (C)) by the second polishing, wt%, and at the same time, a cleansing iron powder obtained by shifting the particle size distribution to the particle side is obtained.

The thus obtained cleaning iron powder is introduced into the second settling tank 51 from the discharge port 59 at the upper part of the water washing apparatus 44. [ As a result, relatively large portions of the washing iron are precipitated in turn, and a layer of the precipitate is formed at the bottom of the second settling tank 51. On the other hand, the helical body 54 in the screw conveyor 52 is rotationally driven by a motor to discharge the sediment from the sedimentation tank 51 to the outside. At this time, the amount of the cleaning iron injected from the discharge port 59 and the amount of the sediment discharged from the sedimentation tank 51 are adjusted to form an overflow flow in the second sedimentation tank 51, And adjusted to a range of 3 to 10 m / hr (average: 5 m / hr) suitable for purification. The acid solution diluted with the liquid after washing from the secondary-stage etching liquid 46 of the second stage at a rate of 30 to 100 l / h of 98 wt% concentrated sulfuric acid having a specific gravity of 1.9 was supplied from the liquid injection port 58 of the acid liquid supply pipe 56 to the screw conveyor (52), and a descending flow by the acid solution is formed inside the screw conveyor (52). Here, the acid washing liquid in the settling tank 51 has a dilution amount of the liquid after cleaning from the second-order etching mask 46 so that the pH becomes 0.5 to 3.

By the above operation, by introducing the cleaning iron into the second settling tank 51, the fine powder portion in the cleaning iron powder is accumulated in the second settling tank 51 on the coarse particle portion washed by the acid, and at the same time, When the iron powder is discharged from the second settling tank 51 by the screw conveyor 52, the impurities in the cleaning iron powder are further eluted and removed by the overflow in the acid solution flowing downward along the screw conveyor 52 do. The coarse grain portion containing the purified iron is selectively discharged from the discharge port 59a on the top of the screw conveyor 52 and the upper clear effluent in the second settling tank 51 is discharged from the upper portion of the second settling tank 51 do.

Next, as shown in Fig. 8, the treated product after the pickling and polishing treatment is treated by using a secondary cleaning etchant 46 having the same structure as that of the water washing apparatus 44, Wash the water. At this time, the cleaning water composed of industrial water is supplied at a supply rate of ¹ to 10 m ³ / hr to remove the remaining acid solution. Then, the processed product after the acid solution treatment is put into the air flow dryer 47 to remove water in the air stream at 150 to 250 캜. The particle size distribution of the purified iron powder 15 after the drying was measured. The results are shown in Table 1 below.

Table 1

A typical composition of the refined iron 15 is such that total Fe containing Fe, FeO and Fe ₂ O ₃ is 96 wt% or more, Fe is 92 wt% or more, FeO 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.

The refined iron 15 is classified using the vibrating sifter 48 having either one of the last fh and the Tyler standard body 100 mesh to 150 mesh. As a result, the refined iron particles 15 having different grain sizes can be separately used as needed. For example, the sieving portion may be made of refined iron for copper removal in the etching waste solution treatment, and the portion that is under the sieve may be used as purified iron for removing nickel.

The above-mentioned Tyler standard body of 100 mesh and 150 mesh is a sieve body having a size of 147 mu m and 104 mu m, respectively.

In this way, as shown in FIG. 15 (D), the impurity (CaO) in the refined iron 15 is treated with a purified iron 15 that has been significantly removed to a range of 0.01 to 0.10 wt% Can be obtained. Therefore, in consideration of economic circumstances, the basic unit of sulfuric acid required for obtaining 1 ton of refined iron as a product is set to 10-4001, and the basic unit of hydrochloric acid is set to a range of 25-7001.

Next, a method of obtaining a reduced aqueous iron chloride solution 17 from the iron chloride-based etching waste solution 11 by the electrolytic apparatus 12 will be described.

Here, as shown in FIG. 2, a ferric chloride-based etching waste liquid 11, which is an etching waste liquid after an etching treatment such as a lead frame, is supplied from the liquid inlet 25 to the electrolytic bath 27 through a waste liquid supply pipe, An operation is performed in which the ferric ^ion (Fe ³⁺ ) in the etching waste liquid 11 is reduced to ferrous iron (Fe ²⁺ ) to form a reduced iron chloride aqueous solution 17. This reduction operation is effective in recovering chlorine gas and making effective use of the chlorine gas. In addition, in the step of removing the impurity metal using the purified iron 15 described below, the purified iron 15 is oxidized, So that the concentration of Fe < ^{2 +} > is prevented from becoming excessively excessive.

Here, the iron oxide-based etching waste fluid 11, and the second iron, and on the concentration and the first concentration of iron ions respectively 100~250g / l, 5~70g / l, chloride ion (Cl ^-) and including a HCl and At the same time, it is an aqueous solution containing nickel ions (Ni ²⁺ ) and copper ions (Cu ²⁺ ) which are impurity metal ions.

The reaction in the cathode plate 23 and the cathode plate 24 in the electrolytic bath 27 of the chlorine-based etching waste solution 11 is shown by the following equation.

Anode: 2Cl ^- ? Cl2? + 2e ^-

Negative electrode: Fe ³⁺ + e ^- > Fe ²⁺

That is, chlorine gas is generated in the positive electrode plate 23, and the ferric ion is reduced to ferrous iron in the negative electrode plate 24, and this total reaction is represented by the following equation.

FeCl ₃ ? FeCl ₂ + (1/2) Cl _2?

The free energy change? G in the whole reaction can be calculated as a change amount before and after the reaction of the free energy (G) of each component, and can be calculated as? G = + 13784 cal / mol. The theoretical electrolytic voltage Eo required for electrolysis can be determined by applying a formula of Eo =? G / zF. Here, F is the paradigm constant, z is the number of moles of electrons involved in the reaction, and based on these values, the theoretical electrolytic voltage Eo = 0.5977 volts is obtained. The electrolytic voltage in the range that does not reduce copper ions and nickel ions present in the ferric chloride-based etching waste solution 11, while causing FeCl ₃ to be electrolyzed under an electrolytic voltage exceeding the theoretical electrolytic voltage Eo, , For example, about 1 volt.

Considering the factors such as the current efficiency, the change efficiency to the direct current, and the electrolytic voltage of the electrolytic bath 27, the amount of electric power actually required is, based on 1000 to 3500 kWh per 1 ton of chlorine gas (Cl ₂ ) The size, shape, etc. of the device 12 can be determined.

Next, referring to FIG. 13, which shows the time evolution of the electrolytic voltage E, the current density D, and the ferric ion concentration C in the reduced aqueous solution of iron chloride 17 in the electrolytic apparatus 12 , And a method for regenerating the iron chloride-based etching waste liquid will be described in more detail.

As shown in FIG. 2, the electrolytic bath 27 is supplied with the iron chloride-based etching waste liquid 11 up to a predetermined level to fill the electrolytic bath 27, and the electrolytic voltage E is applied for a predetermined time, .

Next, the waste water supply pipe and the iron-based etching waste fluid 11 through the fluid inlet (25) being in contact one after another in this way, the width of a pair of electrodes which supply flow rate is 4.6l / hr per (that is, one cell) of 1m ³ (Q), and a reduced aqueous solution of iron chloride (17) having a flow rate substantially equal to the supply flow rate Q is taken out from the liquid outlet (26) for discharging the treatment liquid.

As shown in FIG. 13 (a), the time at the start of the steady state is set to to and the electrolysis voltage E is set to 1.5 V, which is a control range of 1 to 4.5 V (volts).

At this time, as shown in FIG. 13 (b) and 13 (c), the current density D and the ferric ion concentration C are respectively within a predetermined range of ^{2 to} 40 A / L to 50 g / l, which is within a range of 1 to 120 g / l. In the following, chlorine gas is discharged from the chlorine gas outlet 33, so that the desired electrolysis state can be maintained.

As shown in FIG. 13, when the ferric ion concentration C fluctuates to depart from the buttiness in a predetermined range (time t ₁ ), the electrolytic voltage E is adjusted so that the predetermined ferric ion concentration C) can be obtained.

Further, in the case where copper or the like impurity metal has precipitated on the anode plate 24, the iron chloride-based etching waste liquid 11 is supplied to the copper precipitation portion, and by the following reaction with ferric chloride in the liquid The copper can be reused.

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 maintained at zero, or as shown in the range of time t _{4 to} t ₅ , It is also possible to re-dissolve copper that has been deposited by applying a reverse voltage for a predetermined period of time.

Further, since the time (t ₂ ) or lower in the 13 (c) is stable, the following description is omitted.

The temperature of the electrolytic treatment liquid in the electrolysis step is controlled within the range of 30 to 100 占 폚. If the temperature of the electrolytic treatment liquid is lower than 30 占 폚, the electrical resistance becomes large and copper, nickel, and the like are likely to precipitate. On the other hand, when the temperature of the electrolytic treatment liquid exceeds 100 캜, the electrolytic treatment liquid is accelerated, which is undesirable.

The ferric ion in the reduced iron chloride aqueous solution 17 obtained by this electrolytic process is, for example, as shown in the schematic diagram of the transition of the respective ion concentrations shown in FIG. 14, (FIG. 14 (a)), and after the treatment, the iron ion concentration was in the range of 50 to 60 g / l (FIG. 14 (b)). On the other hand, the concentrations of nickel ions (Ni ²⁺ ), copper ions (Cu ²⁺ ), and the like are maintained at values before the treatment. The nickel ion and the copper ion are represented by M ^{n +} in FIG. 14.

As described above, since the concentration of the ferric ion in the reduced iron chloride aqueous solution 17 is set at a level slightly higher than the concentration of the impurity metal ion, the impurity metal ions are not reduced during electrolysis, It is possible to perform an efficient electrolysis treatment.

Table 2 shows electrolysis conditions and the results of the electrolysis apparatus 12 in the steady state described above in Table 2. The chlorine recovery current efficiency, which is the ratio of the current effective for the generation of chlorine gas to all the currents, is 67% do.

Table 2

Next, as shown in FIG. 12, a reduced iron chloride aqueous solution 17, which is an example of a ferric chloride-based waste solution obtained by electrolytically treating the iron chloride-based etching waste solution 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 aqueous iron chloride solution 17 using refined iron powder 15 is described below.

12, the refined iron powder 15 is supplied into the agitating tank 18 through the upper opening of the agitating tank 18 and the reduced iron chloride aqueous solution 17 is supplied to the waste liquid supply valve 86 and / And is supplied to the agitating tank 18 through the treatment liquid inlet 78.

Thereafter, the circulation pump 79 is driven to suck the iron-containing liquid 19 passing through the flow floor through the first circulation flow rate control valve 81 and the second circulation flow rate control valve 82 The iron-containing liquid 19 is fed through the supply flow rate control valve 83 provided at the lowermost part of the stirring tank 18 so as to form a swirling flow in the agitating tank 18 and supplied into the agitating tank 18 Causing a circulation flow from bottom to top.

This makes it possible to float the bottom of the stirring tank 18 to float iron so as to form a flow bottom and to prevent the purified iron 15 from flowing to the reduced aqueous iron chloride solution 17 So that efficient mixing can be realized.

Further, in each of the first to third partitioning portions 71 to 73 arranged so that the sectional areas in the horizontal direction are different from each other, the distribution state of the refined iron 15 and the residence time are different. Therefore, the iron concentration of the iron-containing liquid discharged from the first compartment 71 becomes lower than the iron concentration of the iron-containing liquid discharged from the second compartment 72.

If necessary, the discharge amounts of the iron-containing liquid 19 having different iron concentrations and different degrees of reduction reaction are adjusted by the respective first and second discharge control valves 92 and 93, It is possible to control the property of the discharged iron-containing liquid 19 to be discharged.

In this way, while the fluidized bed having a slurry liquid ratio of 1: 0.6 to 1: 0.7 is formed in the agitating tank 18, the ferrous ion remaining as a result of the reaction with the refined iron powder is turned into ferrous iron A reduction reaction of metal ions having a smaller ionization tendency than that of iron such as copper ions and nickel ions can be performed as shown below and the iron ion treatment liquid 19 can be obtained. Further, even in the case of chromium ions having a smaller ionization tendency than iron, they are also reduced by refined iron.

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 concentration in the slurry, the surface area of the iron powder, the slurry temperature, the chloride ion concentration, etc., and appropriate adjustment can be made by adding these factors or by adding a pH adjuster.

In the step of removing the impurity metal ions, the purified iron (15) elutes into the reduced aqueous solution of iron chloride (17) to generate the ferrous ion, and the reduced iron chloride aqueous solution (17) Or the concentration thereof is reduced, the elution amount of the refined solution 15 can be suppressed to a required minimum limit, and the purified refined iron-containing solution 19 can be efficiently purified without deteriorating the removal of the impurity metal ions, Can be obtained.

The concentration of each metal ion in the iron treatment liquid 19 can be adjusted from the reduced aqueous iron chloride solution 17 (FIG. 14 (b)) after the electrolytic treatment to the impurity metal The amount of ions (Mn ⁺ ) decelerates.

Next, iron powder and other impurities contained in the iron-containing liquid 19 discharged from the agitating tank 18 are removed to prepare an iron-containing liquid containing a large amount of ferrous chloride, Is supplied to the chlorine treatment device 21 and the chlorine gas generated in the electrolysis device 12 or the like is sucked or bubbled into a part or all of the contained ferrous ion Is oxidized to ferric iron to obtain an etchant 20 that has been regenerated.

That is, the chlorine gas generated in the electrolytic device 12 is sucked into the chlorination device 21 as the acid acceptor of ferrous iron, and the ferrous ion remaining in the iron fermentation solution is oxidized. Then, as shown in FIG. 14 (d), the regenerated etchant 20 having the impurity metal ions removed and the FeCl ₃ concentration adjusted to 560 to 730 g / l can be obtained. In this case, there is an advantage that the chlorine gas generated in the waste liquid treatment facility 10 can be utilized effectively in the magnetic facility.

As described above, in the first embodiment, unlike the conventional method of reducing iron ions by using iron powder in advance, the increment of iron ions due to the elution of iron in the reduction step is small, The addition amount of the diluting liquid for adjusting the iron ion concentration can be accommodated within the required minimum range.

In addition, the amount of iron used for reducing and removing copper ions and nickel ions can be greatly reduced, the amount of iron used in all the processes can be reduced, and the cost for iron powder can be suppressed. In addition, It is possible to recover the chlorine gas generated in the chlorination process and effectively utilize it in the chlorination process as the post-process, thereby reducing the chlorine gas cost as much.

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 or decreased, the waste liquid treatment facility 10 can be made compact.

(Second Embodiment)

The method of regenerating the chloride-based etching waste solution according to the second embodiment of the present invention will be described in detail below with reference to FIGS. 16 to 19, The electrolytic apparatus 12 is not used and the stirring tank 18 is connected to the first and second stirring tanks 115 and 119 are used, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the method of regenerating the chloride-based etching waste solution according to the second embodiment, the stirrer of the conventional type is used for the first stirrer 115, It is preferable to use the stirrer 18 of the iron chloride-based waste solution according to the second embodiment after applying the electrolysis method to the iron chloride-based etching waste solution as described above It is possible.

As shown in FIG. 16, the etching waste solution processing facility 110 used in the method for regenerating the iron chloride-based etching waste solution according to the second embodiment includes a removal device 113 for removing copper from the etching waste solution, A nickel removal unit 122 for removing nickel and chromium from the etchant, a device for removing suspended impurities such as carbon and silica (not shown), and a chlorination apparatus for oxidizing the treatment liquid from which the impurities have been removed 21) (see Figure 1). Hereinafter, these will be described in detail.

The shifting device 113 is provided with an etching waste liquid supplied from the etching waste liquid tank 111 and the pH adjuster tank 112 and a necessary amount of a pH adjusting agent and an iron powder supplied from the iron storage tank 114 through the screw feeder 118 , Water supplied from a water source (not shown) (not shown) (for example, water), and a part of the solid material recovered in the deaerator 113 are mixed to discharge the mixed iron mixture mixture 1A containing the reduced copper The first stirring tank 115 and the iron mixed liquid 1A from the first stirring tank 115 are fed and the mixed liquid 1B containing relatively small particles and the mixed iron liquid mixture 1C containing large particles ) For transporting the iron mixture mixture 1A discharged from the first agitating tank 115 to the liquid cyclone 116 through a cone tank (inverted conical tank) 121, A pump 127, and a humidifying unit (not shown) A first Eckins classifier 117 for classifying and washing the mixed liquor 1C to obtain a powdery solid material and a second Eckstein classifier 117 for taking out a part of the solids and re- 117a.

The first stirring tank 115 is a substantially cylindrical FPR vessel and is provided with a stirring blade 128 for forcibly stirring the mixed slurry mixture liquid 1A in the tank. Iron mixed liquor 1A is discharged from the outlet 115a of the bath top.

The first and second Ekinz classifiers 117 and 117a are provided with a dust settling tank 120 and 120a to which an iron mixed liquor 1A containing reduced copper is supplied, (Not shown) for spraying and cleaning the solids in the dust sedimentation baths 120 and 120a by lifting up the solids in the dust sedimentation baths 120 and 120a by raising the solids in the dust collecting baths 120 and 120a and a spraying device have. In the first and second Ekinins classifiers 117 and 117a, the fine particles in the solid matter are classified in the dust settling basins 120 and 120a, the degree of the relatively large particles in the solid matter is large, So that the solids from which moisture has been removed are discharged from the upper ends of the solid ascending tubes (not shown).

The de-nickel device 122 includes a dehydrating process liquid 1B discharged from the liquid cyclone 116 of the device 113, iron powder supplied from the iron storage tank 114a, A second stirring tank 119 for discharging the primary iron processing liquid 2B containing nickel ions and chromium ions reduced by mixing the recovered solids in the iron removal unit 122, And the primary iron treatment liquid 2B to be supplied are supplied to the secondary stirring tank 119 through a screw dehydrating treatment liquid 2C containing iron fine particles and nickel A liquid cyclone 116a for separating the iron chloride mixture liquid 2D containing the precipitated iron particles and a primary iron fraction 2B discharged from the second agitator 119 through the cone tank 121a A pump 127a for transporting the liquid to the liquid cyclone 116a, An Ekinch classifier 117b for making the liquid 2D into a powder of nickel and nickel-attached iron powder and a coagulant of the flocculant tank 125 to the denitrification liquid 2C from the liquid cyclone 116a And an agitating tank 124 for storing the agitated liquid.

16, depending on the type of the iron chloride-based etching waste liquid, the etching liquid W is supplied from the etching waste liquid tank 111 to the etching liquid waste 1B supplied to the second stirring tank 119, May be directly supplied as necessary.

As shown in FIG. 17, the volume of the second stirring tank 119 is divided into five areas, that is, the first to fifth compartments 130 to 134, which are configured to have different horizontal cross-sectional areas in the vertical direction 17 m ³ , and a maximum inside diameter of about 3.2 m, and it is possible to maintain about 21 tons of iron for treating the etching waste solution.

A stirring blade (128a) for stirring the iron particles and the deodorizing solution (1B), which is an example of the iron chloride-based waste solution supplied in the second stirring tank (119) And a motor 129 for rotationally driving the motor 128a. The iron powder 2E is taken out from the upper part of the stirring tank 119 and supplied to the lower part by the circulating pump 126 without stirring the slurry by the stirring wing 128a, The slurry having a solid liquid ratio of 1: 1, which is a weight ratio between iron and liquid, is made to be 1.5 times as much as that of the stirring type reaction vessel driven by a stirring blade rotated by a conventional motor Of processing speed.

The first compartment 130, which is the uppermost part of the second stirring tank 119, is an area made up of a straight section having a maximum cross-sectional area in the horizontal direction, and the upper end opening thereof is open to the atmosphere. The refined iron powder 15 produced by the above-described method can be introduced. On the other hand, the second partitioning portion 131 following the first partitioning portion 130 is an area made of a tapered portion whose diameter is gradually reduced toward the downward direction.

On the other hand, a third compartment 132 is formed in the lower portion of the second compartment 131 and has the same cross-sectional area as the lower end of the second compartment 131. The third compartment 132 A fourth partitioning part 133 consisting of a tapered part is provided successively at the lower end of the fourth partitioning part 133 and a fifth partitioning part 134 composed of a small diameter straight part is provided successively at the lower end of the fourth partitioning part 133 . Then, in the third to fifth partitioning parts 132 to 134, the supplied iron powder, the iron powder processing solution 2E supplied from the lower part and the deodorizing solution 1B treated with the iron chloride etching solution As indicated by hatching in the figure, a flow floor with a high iron powder density is formed. In the first and second partition sections 130 and 131 where the rising flow rate is slow, the falling rate of the iron powder is faster than the flow rate of the treatment liquid, and thus the iron powder separator (freeboard) having a very small iron powder density is formed.

The first partitioning part 130 and the second partitioning part 131 forming the iron separating part are respectively provided with treatment liquid part extracting ports 145 and 145a and a fifth compartment A treatment liquid inlet 145b is provided in the side wall of the portion 134. [

The process liquid inlet ports 145 and 145a and the process liquid inlet port 145b are connected to each other through a process liquid circulation pipe 145d having a circulation pump 126 in between. Therefore, by driving the circulation pump 126, the iron-containing processing liquid 2E having a small iron content is taken out from the first and second compartments 130 and 131 through the processing-liquid part outlet ports 145 and 145a, Thereafter, a ferrofluid treatment liquid 2E is introduced into the fifth compartment 134 through the treatment liquid circulation pipe 145d and the treatment liquid inlet 145b so that a self-circulating flow is generated in the second stirring tank 119 And the flow floor described above is formed in the third to fifth partitioning parts 132 to 134.

The upper end of the treatment liquid circulation pipe 145d is provided with a first liquid flow control valve 145d for controlling the flow rate of the iron liquid processing solution 2E passing through the treatment liquid circulation pipe 145d through the treatment liquid part outlet ports 145, And the second circulation flow control valves 135 and 136 are provided at the lower end of the treatment liquid circulation pipe 145d. The supply flow control valve 143 is provided at the lower end of the treatment liquid circulation pipe 145d. By using the first and second circulating flow control valves 135 and 136 and the supply flow control valve 143, it is possible to easily control the flow rate of the circulating liquid. Therefore, regardless of the amount of the supplied untreating solution 1B supplied through the supply piping 147 of the untreating solution supplied on the way of the waste liquid supply valve 142, the circulation flow is supplied to the second stirring tank 119 The flow state of the supplied iron powder can be maintained in an appropriate range, and the flow bottom 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 detached from the second stirring tank 119.

The iron powder 2E or the like is discharged to the fifth compartment 134 provided at the lowermost portion of the second stirring tank 119 and made of a small-diameter straight portion which is easy to precipitate iron particles, And generation of dead space in the second stirring tank 119 can be suppressed.

The first liquid processing liquid 2B as the processing liquid is supplied with the processing liquid discharging ports 145e and 145f in the first partitioning part 130 forming the iron separating part and the side wall part of the second dividing part 131 A process liquid transfer pipe 127c having a cone tank 121a (see FIG. 16) and a pump 127a is connected to the process liquid discharge ports 145e and 145f, 127c are connected to the liquid cyclone 116a. Here, the discharge side of the metering pump 127a is returned to some of the cone tanks 121a to adjust the flow rate of the whole. The flow rates of the primary iron processing liquid 2B discharged from the processing liquid discharging ports 145e and 145f are set such that the flow rate of the primary iron processing liquid 2B flowing through the processing liquid transfer pipes 127c following the respective processing liquid discharging ports 145e and 145f The first discharge flow rate control valve 138 and the second discharge flow rate control valve 139 installed in the position.

In this manner, the primary iron processing liquid 2B can be selected as needed from the reaction dividing portions having different processing conditions, and the primary iron processing liquid 2B having different component characteristics can be taken out from the plurality of partitioning portions have.

When the purified iron 15 in the second stirring tank 119 is insufficient, the purified iron 15 is supplied from above the stirring tank 119.

A discharge pipe 146a provided with a bottom discharge valve 146 for discharging the solid substances settled at the bottom portion is provided at the bottom of the second stirring tank 119 and a solid matter or the like is drawn therefrom You can.

Table 3 below shows treatment conditions and treatment results of the second agitating tank 119 described above together with comparative examples.

Table 3

Next, a method of treating a ferric chloride-based etching waste solution using the above-mentioned method for recycling a ferric chloride-based etching waste solution according to the second embodiment of the present invention using the above-mentioned etching-liquid waste treatment facility 110 will be described in more detail. Here, in the stirring process of the first stirring tank 115, an example using the stirring wing according to the conventional method is shown, but by changing to the stirring tank 18 using the flowing bottom according to the first embodiment This makes it possible to provide a more efficient and economical method of recycling the waste solution of the etching solution of the iron chloride based etchant.

First, as shown in FIG. 16, a predetermined amount of iron powder is charged into the first stirring tank 115 and the second stirring tank 119 from the iron storage tanks 114 and 114a through the screw feeders 118 and 118a . As the iron powder for reducing the impurity metal ion, for example, those having a particle diameter of 44 to 250 m can be used. Further, an aqueous solution containing metal ions such as copper, nickel, chromium, and the like is used as the iron chloride-based etching waste solution by etching a shadow mask, a lead frame or the like to lower the concentration of ferric chloride (FeCl ₃ ) .

The iron chloride-based etching waste liquid is supplied from the etching waste liquid tank 111 to the first stirring tank 115 through a pump and the stirring blade 128 is rotated to suspend and mix the iron powder in the iron chloride- To prepare a mixed slurry.

In this mixed slurry, the copper ions having a smaller ionization tendency than iron (Fe) are reduced to precipitate copper, and the iron powder is eluted as iron ion in the liquid and is treated with iron, and a mixture of iron containing a small amount of iron (1A). A pH adjuster such as hydrochloric acid may be added to the mixed slurry if necessary to adjust the pH value of the mixed slurry to a range of, for example, 0.5 to 1.5 to maintain the rate or efficiency of the reduction reaction within a predetermined range .

Next, this iron mixture liquid 1A is taken out from an outlet 115a provided on the upper portion of the first agitating tank 115 and sent to the cone tank 121. And the iron mixture liquid 1A of the cone tank 121 is supplied to the liquid cyclone 116 through the pump 127. [

The liquid cyclone 116 separates the iron mixture liquid 1A into a mixed hammed iron mixture 1C having a large amount of iron powder containing copper and a deodorizing solution 1B having copper and iron placenta removed. The mixed iron liquid mixture 1C discharged from the lower portion of the liquid cyclone 116 is cleaned and classified by the first and second ethx classifiers 117 and 117a and finally the copper powder 117e is obtained Loses. It is also possible to recover a part of the slurry containing a large amount of iron powder treated with the first Echin's classifier 117 and supply it to the first agitating tank 115.

On the other hand, the deodorizing liquid 1B discharged from the upper portion of the liquid cyclone 116 is supplied to the denitration device 122, and impurity metals such as nickel and chromium are removed by the following procedure. First, as shown in FIG. 16 and FIG. 17, the deodorizing treatment liquid 1B is supplied to the second stirring tank 119 through the waste liquid supply valve 142, and the purified iron from the iron storage tank 114a (15) is continuously supplied through the screw feeder (118a). Here, the stirring vane 128a can be driven by the motor 129 at a predetermined rotation speed, for example, a rotation speed of 5 to 60 rpm. However, in the case where stirring of the second stirring tank 119 is performed by the stirring vane 128a, since the specific gravity of the iron powder in the deodorizing liquid 1B is remarkably larger than that of the liquid portion, And the iron powder precipitates and deposits on the bottom of the second stirring tank 119, causing a dead space to occur, and the reaction efficiency between the iron powder and the deodorizing solution can not be maintained at a predetermined level. Further, when the output of the motor 129 is raised to rotate the stirring vane 128a at a high speed to stir the to-be-treated liquid 1B with strong stirring, the dead space in the second stirring tank 119 becomes small, The power consumption of the motor 129 is increased more than necessary and the abrasion of the crude wall 119 and the like of the second agitating tank 119 constituted by the FPR and the like is increased and the cost of maintenance such as the exchange of the crude oil is increased , And the stirring wing 128a also wears.

Thus, without using the stirring vane 128a, and if necessary, the stirring vane 128a is removed from the second stirring tank 119, and the circulation pump 126 is driven as shown in FIG. 17 The iron refining liquid 2E containing a small amount of iron is sucked through the first refining flow rate control valve 135 and the second circulation flow rate control valve 136 and at the lowermost part of the second stirring tank 119 The iron-containing liquid 2E is fed through the feed flow control valve 143 at an angle so as to form a swirling flow in the second agitating tank 119 and is supplied into the second agitating tank 119 from the bottom to the top Causing circulation. This makes it possible to float iron particles that tend to precipitate on the bottom of the second agitating tank 119 and solve the dead space in the tank and even if the motor output of the circulating pump 126 is small, 1B) can be realized efficiently.

Since the first compartment 130 has a straight shape and is located at an upper position and the second compartment is tapered, the distribution state of the iron powder, the residence time and the like are different. The first compartment 130 is discharged from the first compartment 130 The iron concentration of the iron treatment liquid is lower than the iron concentration of the iron treatment liquid discharged from the second compartment 131. If necessary, the discharge amounts of the iron-containing liquids different in iron concentration and different in the degree of reduction reaction are adjusted by the respective first and second discharge flow control valves 138 and 139, It is possible to control the properties of the primary iron treatment liquid 2B to be discharged. In this embodiment, while the desired circulating flow is formed in the second stirring tank 119, the stirring vane 128a is rotated at low speed, and the maximum value of the main velocity is maintained at 1 m / s. As a result, a swirling flow is generated in addition to the rising flow, so that the stirring efficiency can be expected to be improved. In this case, if the stirring vane 128a is rotated at a medium speed or a high speed, wear of the second stirring tank 119 and the stirring vane 128a is undesirably caused.

In this way, a reduction reaction of nickel ions, chromium ions, etc. by iron powder can be caused as shown below to obtain the primary iron material treatment liquid 2B.

2FeCl 3 + Fe 3FeCl ₂

NiCl ₂ + Fe? FeCl ₂ + Ni ↓

Therefore, such a reduction reaction also depends on the iron 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., Can be adjusted appropriately. The weight ratio of the slurry 2A in the second agitating tank 119 at this time was 1: (0.6 to 0.7) as shown in Table 3.

The obtained primary iron processing solution 2B is fed into the cone tank 121a and fed to the nickel depletion treatment liquid 2C and the nickel iron mixed solution 2D by the liquid cyclone 116a through the pump 127a Respectively. A part of the nickel iron mixture liquid 2D discharged from the lower portion of the liquid cyclone 116a is returned to the second stirring tank 119 and a portion of the placenta is sent to the Ekinch classifier 117b, The nickel-attached iron powder 117f is separated. The de-nickel processing liquid 2C discharged from the upper part of the liquid cyclone 116a is supplied to the removal device for removal of suspended impurities (not shown) after the addition of the coagulant supplied from the coagulant tank 125 in the stirring tank 124, As shown in FIG.

The nickel removal solution 2C containing a suspension impurity such as carbon (carbon) or silica (silicon dioxide) is treated by a solid-liquid separator such as a decanter, and the suspension impurity and the secondary Is separated into the iron-containing solution 2F (corresponding to the iron-containing solution 19 in FIG. 1) and eventually chlorinated to form the regenerated etchant 20.

Here, the comparative example shown in Table 3 is a comparative example shown in Table 3, in which the volume of the reaction vessel is 11 m ³ , the maximum flow rate (main velocity) of the slurry is 6 m / s, This is an example using a mechanical stirring tank. In the second embodiment, the maximum flow rate can be made slower from 6 m / s to 1 m / s as compared with the comparative example shown in Table 3, and the liquid ratio can be increased from the conventional 1: 3 to 1: (0.6 to 0.7) have. In this way, the treatment efficiency can be improved, and the wear of the second agitating tank 119 can be reduced, and the cost for repairing the apparatus can be reduced. In addition, since iron powder having a relatively large particle diameter can be used, the cost of raw materials can be reduced.

Next, a description will be given of a third agitating tank 150, which is a modification of the second agitating tank 119 used in the regeneration method of the iron chloride-based etching waste liquid according to the second embodiment of the present invention described above.

As shown in FIG. 18 and FIG. 19, the third stirring tank 150 is divided into three regions (first to third dividing regions 151 to 153) configured to have different horizontal cross-sectional areas in the vertical direction, The iron powder for treating the iron chloride-based etching waste liquid or the refined iron powder 15 produced by the iron refining equipment 16 described above is held in advance in a predetermined amount in the third stirring tank 150, The amount of consumed iron powder is continuously supplied from the iron supply device that is not in contact with the third stirring tank 150 when the third stirring tank 150 is operated.

A partition plate 155 for dividing the third compartment 153 and the fluid supply unit 154 under the third compartment 153 is provided in the inner part of the third stirring tank 150. A nozzle 156 called Tweed wire is disposed on the partition plate 155 to distribute the process liquid supplied from the fluid supply unit 154 under the partition plate 155 in a horizontal direction on the partition plate 155 Are arranged in a lattice shape or a lattice shape. The first compartment 151, which is an iron separator, is provided with an outlet 157 for extracting the amount of the iron-containing liquid 3A necessary for forming the flow bottom.

The extracted iron processing liquid 3A is supplied to the supply port 159 provided on the side of the fluid supply unit 154 through the circulation pump 158 to fluidize the iron in the third stirring tank 150 So as to form a purified flow.

The bottom portion and / or the side portion of the fluid supply portion 154 is provided with a supply port 160 for a deodorizing process fluid for supplying the deodorizing process fluid 1B processed by the first stirrer tank 115 and its associated equipment And the iron fraction 3B (corresponding to the iron fraction 19 in the first embodiment) is disposed in the first compartment 151 above the third stirring tank 150 A discharge port 161 is provided.

When the circulation pump 158 is operated, the third liquid in the third stirring tank 150 is discharged by the discharge of the processing liquid supplied to the flow bottom through the nozzle 150, Is maintained.

In this modified example, the maximum flow rate of the slurry is set to be 6 m / s, as compared with the case of using the stirring tank according to the comparative example in which the stirring blade is used to stir the iron powder and the treatment liquid, To 0.25 m / s, and the treatment can be performed by raising the liquid-to-liquid ratio to 1: 1, which is larger than 1: 3.

Further, as shown in the items of the iron particle diameter constraint in Table 3, in the second embodiment and its modifications, since the control of the stirring conditions can be facilitated by forming the circulating system of the treatment liquid inside, The degree of the iron particles can be widely obtained from small particles to medium particles. On the other hand, in the case of the comparative example, it can be seen that it is limited to small particles and the raw material cost is increased.

In the method for regenerating the iron chloride-based etching waste solution according to the present invention, the iron-containing solution passing through the flowing bottom is circulated and supplied from the bottom of the stirring tank to form the flow bottom of the iron powder. Effect is obtained.

(1) The amount of the fluid medium required to maintain the state of the flowing bottom in an appropriate range can be treated with an iron-processing liquid which elutes from the upper part of the stirring tank.

Therefore, when the supply rate of the supplied iron chloride-based waste liquid is insufficient, the iron particles are kept in a good fluidized state by the self-circulating flow using a part of the iron-containing fluid formed in the stirring tank, and the supply rate of the iron chloride- , The iron chloride-based waste solution can be subjected to the reduction treatment under stable conditions at all times by adjusting the self-circulating amount of the iron-containing waste solution by reducing the self-circulating amount.

(2) The shape of the stirring tank is enlarged upwardly, and the discharging position of the iron-processing liquid can be appropriately arranged so that the dead space of the stirring tank can be substantially eliminated, and the efficiency of the impurity metal ion Can be increased.

③ Since the movement of iron in the flow floor is made uniform, it does not cause local wear due to flow of iron as compared with the case of using a fluidized bed of mechanical stirring, Can be reduced.

④ Good agitation of iron and iron chloride waste can be ensured in a relatively narrow space. Therefore, the entire apparatus can be configured compactly.

Here, in particular, when the ferric chloride-based waste liquid is supplied from the bottom portion of the agitating tank, the ferric chloride-based waste liquid may not be mixed with the treatment liquid, or the iron chloride-based liquid phase may be supplied to form the fluidized bed.

Further, in the method for regenerating the iron chloride-based etching waste solution according to the present invention, it is preferable that the upper portion of the stirring tank is enlarged in diameter from the main body portion, thereby slowing the speed of the fluidizing medium ascending in the stirring tank, . ≪ / RTI > Further, even if the flow rate in the bath fluctuates somewhat, the upper end of the flow floor can be kept not to exceed the predetermined position, and the iron powder is less likely to be mixed with the iron powder treatment liquid. Metal ions can be removed, and the removal efficiency of the impurity metal ions can be further improved.

In the method for regenerating the iron chloride-based etching waste solution of the present invention, it is also possible to obtain the iron chloride-based waste solution to be supplied and to reduce a part or almost of the ferric ion in the original waste solution to the ferric ion by electrolysis treatment . As a result, the ferric ion is reduced by the negative electrode reaction, so that the total iron ion concentration of the ferrous ion and the ferric ion in the liquid does not change. Therefore, it is not necessary to use a large amount of a diluting liquid (specifically, water) in order to set the concentration of ferric ion to a predetermined concentration in the regeneration treatment of the iron chloride-based waste liquid, and the cost for the treatment of the surplus liquid can be reduced And at the same time, it is possible to further make the treatment facilities more compact. Further, since the amount of iron used in the regeneration treatment of the iron chloride-based waste solution can be reduced, the cost of treating the iron chloride-based waste solution can be reduced.

Further, in the method for regenerating a waste solution of a ferric chloride-based etching solution according to the present invention, it is also possible to control the electrolytic voltage of the ferric chloride-based waste solution in a specific range in the electrolytic treatment. Thereby, the reduction of ferric ion can be carried out without precipitating impurity metal ions such as copper and nickel contained in the iron chloride-based etching waste solution, and the regeneration treatment of the iron chloride-based waste solution can be performed more efficiently.

In the method for regenerating the chloride-based etching waste solution according to the present invention, the inter-electrode distance between the positive electrode plate and the negative electrode plate of the electrolytic bath in the electrolytic treatment can be set within a specific range, and thereby the intrusion of chlorine gas generated in the positive electrode plate into the negative electrode chamber The oxidation of the ferrous ion can be inhibited, and the increase of the electrolytic voltage can be suppressed.

In the method for regenerating the iron chloride-based etching waste solution according to the present invention, the iron chloride-based etching waste solution is supplied to the cathode chamber side of the electrolytic bath partitioned by the diaphragm from the anode chamber side and the cathode chamber side, It may be taken out from another part of the apparatus. Thereby, the interference between the chlorine gas generated in the negative electrode plate and the supplied iron chloride-based etching waste liquid is suppressed, and efficient electrolysis can be performed.

In the method for regenerating the iron chloride-based etching waste solution according to the present invention, the concentration of ferric ion in the aqueous solution of reduced iron chloride may be set to 10 to 120 g / l. Thereby, impurity metal ions such as copper and nickel in the aqueous solution of iron chloride are not reduced, and it is possible to reduce the cost of the subsequent regeneration treatment without causing any trouble in the subsequent regeneration treatment.

In the method for regenerating the chloride-based etching waste solution according to the present invention, the chlorine gas generated in the electrolytic treatment is sucked into the iron-containing treatment liquid discharged from the stirring tank, and a part of the ferrous ion contained in the iron- It is also possible to oxidize ferric iron to on. This makes it possible to adjust the concentration of ferric ion in the iron-containing treatment liquid from which impurity metal ions have been removed to a desired value without generating unnecessary by-products, and efficiently obtain a regeneration solution of the aqueous solution of iron chloride solution adjusted to the required components and concentrations .

In the method for regenerating the iron chloride-based etching waste solution according to the present invention, the iron powder is recovered from the dust containing impurities such as CaO generated from the steelmaking furnace by a wet method, the iron dust is pulverized and water- It is also possible to use purified iron oxide that has been oxidized. Thereby, it is possible to cheaply regenerate the brine iron-based waste liquid using refined iron having a small difference obtained by treating the dust produced from the steelmaking furnace and having high purity.

In the method of regenerating the iron chloride-based etching waste liquid according to the present invention, the pickling of the iron dust can be performed in a process in which the pickling of the iron dust is carried out by a screw conveyor provided with an acid injection port at an upper portion thereof. Thereby, the iron powder used for the reduction treatment of the iron chloride-based waste solution can be obtained in a large amount and inexpensively by the continuous treatment, and the recovery treatment of the iron chloride-based waste solution can be performed at low cost.

Claims (11)

An iron chloride is mixed with a ferric chloride waste solution containing metal ions having a smaller ionization tendency than iron such as copper or nickel in a stirring tank and the iron ion is reacted with the metal ion to precipitate and remove the metal ion, A method of regenerating a ferric chloride-based etching waste solution which oxidizes a solution, The iron chloride waste solution is supplied to the stirring tank and the iron treatment liquid after the iron powder is reacted from the upper part of the stirring tank is taken out and circulated to the bottom of the stirring tank to form a floating bottom in which the iron powder disperses and floats And a surplus iron solution is taken out from the upper part of the stirring tank. The method according to claim 1, wherein the iron chloride-based waste liquid is supplied from a bottom portion of the stirring tank to promote the formation of the flowing bottom. 2. The method according to claim 1, wherein an upper portion of the stirring tank is provided with an iron separator provided with an iron separator for increasing the diameter of the floating bottom forming portion, A method of regenerating a waste solution of the system etching. The ferric chloride-based waste solution as set forth in claim 1, wherein the iron chloride-based waste solution to be contained in the stirring tank is a solution of a ferric chloride-based etching solution which is an aqueous solution of reduced iron chloride in which a part or almost of ferric ion is reduced to electrolytic iron Playback method. 5. The method according to claim 4, wherein the electrolytic voltage of the ferric chloride-based etching waste solution in the electrolytic treatment is controlled to ¹ to 4.5 V and the current density is in the range of ² to 40 A / dm ² . The method according to claim 4, wherein the distance between the positive and negative electrodes of the electrolytic bath in the electrolytic treatment is 1.5 to 50 mm. The electrolytic cell according to claim 4, wherein the electrolytic bath for carrying out the electrolytic treatment is divided into a cathode chamber having a cathode and an anode chamber having a cathode by a liquid-permeable diaphragm, Wherein the reducing iron chloride aqueous solution is supplied from a portion of the cathode chamber and subjected to reduction treatment through the cathode chamber is taken out from another portion of the cathode chamber. The method according to claim 4, wherein the concentration of ferric ion remaining in the reduced aqueous solution of iron chloride is 10 to 120 g / l. The method according to claim 4, wherein part or all of the chlorine gas generated from the anode in the electrolytic treatment is used for the oxidation treatment of the iron-containing solution. The method of claim 1, wherein the iron powder is recovered from a dust containing impurities such as CaO generated from a steelmaking furnace by a wet method, the iron dust is pulverized to remove water and the impurities are removed, A method for regenerating a waste solution of refined iron chloride based etching solution. The method according to claim 10, wherein the pickling of the iron dust is performed by a method of regenerating a ferric chloride-based etching waste solution which is performed in a process of being gradually inclined to a sedimentation tank storing the iron dust and being gradually discharged by a screw conveyor provided with an acid- .

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