A system and method for recycling ferric chloride etching solution

Abstract

The present invention relates to a ferric chloride etching solution recycling system and method, comprising: separating copper ions in the etching solution from the solution in the form of sponge copper through a replacement reaction; adding the replaced etching solution to an oxygen reactor for oxidation regeneration of the ferric chloride etching solution; adding a small amount of hydrochloric acid to the regenerated etching solution to restore the etching solution to its original acidity; recycling the etching solution, processing the incremental etching solution into a by-product, and not generating waste etching solution. The present invention processes the waste etching solution online to achieve recycling, can quickly and effectively regenerate the ferric chloride etching solution, can reduce the use of oxidants, and does not generate dangerous gas chlorine during the regeneration process, can meet low-acidity production, effectively reduce hydrochloric acid mist in the workshop, can reduce production costs while not generating waste etching solution, and realizes online recycling of ferric chloride etching waste solution.

Description

Technical Field

[0001] The invention relates to the technical field of replacement oxidation and redox preparation, and in particular to a ferric chloride etching solution regeneration system and method. Background Art

[0002] Since the 1960s, etching solutions have undergone various types of updates and improvements, mainly including ferric chloride etching solutions, ammonium persulfate etching solutions, sulfuric acid / chromic acid etching solutions, sulfuric acid / hydrogen peroxide etching solutions, alkaline cupric chloride etching solutions, acidic cupric chloride etching solutions, etc. In the early stages of PCB development, the circuits were relatively simple, and ferric chloride etching solutions had a fast etching speed and low price, and were widely used in the etching of single and double-layer circuit boards. However, with the rapid development of PCBs, the requirements of national environmental protection policies, and the industry's increasing requirements for high-precision and high-density circuits, ferric chloride etching solutions have gradually withdrawn from the market due to the difficulty in regenerating, difficult waste liquid treatment, and large incremental problems. However, ammonium persulfate etching solutions, chromium-containing etching solutions, and sulfuric acid-hydrogen peroxide system etching solutions have not been accepted by the market due to the problems of difficulty in regeneration or toxicity.

[0003] The acid copper chloride etching system has the advantages of fast etching speed, good stability, uniform etching, small side erosion, and easy regeneration. The alkaline copper chloride etching system has the characteristics of high copper dissolution, small side erosion, fast etching rate and easy control of etching rate, which meets the current printed circuit board etching needs and is currently the most widely used two etching solutions. At present, high-precision and high-thickness copper plate etching will be urgently needed, and with the increase of environmental protection efforts, alkaline ammonia etching solutions will also be eliminated or replaced, so it is urgent to develop new environmentally friendly etching solutions for high-precision and high-thickness copper etching.

[0004] Chinese patent CN110857470A provides a method for regenerating and circulating ferric chloride etching solution. The method uses an electrolytic cell for electrolysis. During electrolysis, Fe in the ferric chloride waste liquid in the anode chamber is 2+ Oxidized to Fe 3+ , H in the cathode chamber + The hydrogen produced by this method may leak and cause explosion risk.

[0005] Japanese patent JP97114023 proposes replacing heavy metals with iron powder and oxidizing divalent iron by electrolysis. The invention proposes a method of using electrolysis in the regeneration process. This method produces chlorine gas during the electrolysis process, which has achieved the purpose of oxidation, but the chlorine gas may leak and is very harmful.

[0006] Chinese patent 200910028729.9 provides a method for regenerating and recovering etching waste liquid containing copper chloride and ferric chloride, using iron powder to replace copper and oxidizing with hydrogen peroxide. The hydrogen peroxide in this method is highly oxidizing and has high storage requirements. It is dangerous. The etching liquid will increase in the regeneration process and produce waste etching liquid, and the external transfer must be controlled as hazardous waste.

[0007] Therefore, the existing technologies have not been able to effectively solve the problem of difficult treatment and large increase of ferric chloride etching waste liquid. Summary of the invention

[0008] In view of this, the present invention provides a system and method for regenerating ferric chloride etching solution.

[0009] Compared with the traditional ferric chloride etching method, the present invention has low energy consumption and does not produce highly dangerous gases such as chlorine during the regeneration process, thus achieving clean production and green environmental protection; at the same time, no difficult-to-treat ammonia nitrogen wastewater is produced during the regeneration process, the workshop production environment is improved, and the acid mist in the low-acidity environment has little impact on operators; and there is no need to purchase new etching liquid. Compared with the prior art, the method of the present invention can effectively save enterprise costs and expand profits. At the same time, the implementation of the present invention occupies a small area and is easy to operate.

[0010] The technical solution of the present invention is:

[0011] A ferric chloride etching solution recycling system, characterized in that it comprises a stirring tank, an iron powder bin is provided above the stirring tank, one end of the iron powder bin is connected to an iron powder feeding end; one side of the stirring tank is connected to an etching line discharge end;

[0012] A first centrifugal pump is connected below the stirring tank, the first centrifugal pump is provided with a sponge copper discharge end, and the first centrifugal pump is connected to a first filtrate tank;

[0013] It also includes an integrated reactor and a second centrifugal pump, wherein the integrated reactor is connected to the first filtrate tank and the second centrifugal pump respectively;

[0014] The second centrifugal pump is provided with a hydroxy iron discharge end, the second centrifugal pump is connected to a second filtrate tank, and one side of the second filtrate tank is connected to a heat exchanger.

[0015] Furthermore, the integrated reactor is an integrated secondary oxidation reactor.

[0016] In particular, the integrated reactor can be implemented by using other forms of oxidation reactors in the prior art.

[0017] Furthermore, the integrated reactor includes a body, a first ejector, a second ejector, an exhaust pipe, a first circulation pump, and a second circulation pump; a port on the top of the body is connected to a pressure gauge; the middle area of ​​the top of the body is connected to the lower port of the first ejector, and the right side of the first ejector is connected to the exhaust pipe; the left side of the top of the body is connected to the lower port of the second ejector, and the right side of the second ejector is connected to another port on the left side of the top of the body; an oxygen feed end is provided on the left side of the bottom of the body; a thermometer is connected to the right side of the bottom of the body; the middle area of ​​the bottom of the body is connected to the first circulation pump, the middle side of the body is connected to the second circulation pump, the first circulation pump is connected to the upper port of the first ejector, and the second circulation pump is connected to the upper port of the second ejector; and an exhaust gas outlet is provided on the upper part of the body.

[0018] Furthermore, the second filtrate tank is connected to a hydrochloric acid inlet; and the heat exchanger is respectively provided with a cooling water inlet and a regenerated product outlet.

[0019] Furthermore, a stirring paddle is provided in the stirring tank.

[0020] The present invention also provides a method for recycling ferric chloride etching solution, characterized in that it comprises the above recycling system; and comprises the following steps:

[0021] A. Continuously transport the copper-containing ferric chloride etching waste liquid of the etching line into the stirring tank, control the liquid level of the stirring tank at 40-70% of the effective volume, continuously add an appropriate amount of iron powder, so that the remaining FeCl3 in the ferric chloride etching waste liquid is completely reduced to FeCl2, and the copper ions are replaced by elemental copper, control the ORP to be stable within a certain range, ensure that the copper content in the etching waste liquid is less than 8-12g / L, maintain normal pressure, and control the reaction temperature to 80-90℃;

[0022] B. Use the first centrifugal pump to separate the solid-liquid separation of the bottom material in the stirring tank, separate the copper powder and ferrous water in the material, and the separated ferrous water enters the subsequent integrated reactor through a pipeline for oxygen oxidation treatment;

[0023] C. The material in the integrated reactor is pumped from the bottom of the reactor, with one part of the material circulating by itself and the other part feeding the next reactor. The material flow rate is controlled so that the divalent iron ions in the material are gradually and completely oxidized through the two-stage reaction, and the mass fraction of divalent iron ions in the discharge of the secondary reactor is controlled to be ≤0.1-0.5%;

[0024] D. The lack of acid during the oxidation process in the integrated reactor causes hydrolysis to produce byproducts of solid hydroxy iron and ferric chloride. After the secondary reaction, the discharge is separated by the second centrifuge to obtain solid hydroxy iron and liquid ferric chloride;

[0025] E. The liquid ferric chloride separated from the integrated reactor is continuously supplemented with a certain amount of hydrochloric acid for heat exchange to 50-55°C and then returned to the etching line for etching.

[0026] Furthermore, in step A, the copper content of the copper-containing ferric chloride etching waste liquid is 5%-6%, the iron content is 7%-9%, and the iron powder is 95% iron.

[0027] Furthermore, in step A, when the ORP of the material discharged from the stirring tank is less than 100 mv, iron powder is automatically added.

[0028] Furthermore, in step C, ferrous water is continuously fed into the primary reactor of the integrated reactor, and oxygen is introduced from the bottom of the secondary reactor, so that the system pressure of the integrated reactor is 0.1-0.3 MPa and the reaction temperature is 80-100°C.

[0029] Oxygen is introduced into the reactor through a pneumatic regulating valve, which adjusts the valve opening according to the difference between the set pressure and the actual pressure. When the system pressure exceeds the set value, the oxygen supply stops, and the tail gas is discharged from the gas phase balance pipe and absorbed by liquid alkali until the system pressure drops to the set value.

[0030] Furthermore, in the integrated reactor, after the primary reaction, the degree of oxidation of the material is 60-80%; after the secondary reaction, the degree of oxidation of the material is 20-40%.

[0031] The solid hydroxy iron and ferric chloride are produced as by-products during the secondary discharge process of the integrated reactor. The solid hydroxy iron contains 5% chloride ions, 35% iron content and 45% water content, wherein the iron content is equal to the iron powder in the replacement process, so that the chloride ion and water content are equal to the amount of added hydrochloric acid and oxygen; therefore, the content and amount of ferric chloride regenerated at this time remain unchanged, so the method generates no waste.

[0032] Furthermore, in step E, the integrated reactor discharges the material to the etching line, specifically by introducing cold water into the discharge heat exchanger for heat exchange, so that the material reaction temperature is 50-55° C. The liquid ferric chloride separated from the integrated reactor is continuously supplemented with a certain amount of hydrochloric acid for heat exchange. The added hydrochloric acid is to maintain the chlorine taken away by the by-product. The ferric chloride is cooled to 50-55 degrees after heat exchange to meet the production needs of the etching line.

[0033] The beneficial effects of the present invention are:

[0034] 1. The original process of the etching process line remains unchanged and is consistent with the copper chloride system;

[0035] 2. Except for the first batch of etching solution, there is no need to purchase additional etching solution, and it can be recycled indefinitely;

[0036] 3. Add etching solution regularly to maintain high trivalent iron content in the etching solution to achieve efficient etching effect;

[0037] 4. No dangerous gases such as chlorine are produced, and the impact of acid mist on the on-site environment is small;

[0038] 5. The incremental amount of ferric chloride etching solution can be processed into by-products without producing difficult-to-treat ammonia nitrogen wastewater;

[0039] 6. Small footprint and easy to operate;

[0040] 7. It can realize continuous online regeneration production with feeding and discharging at the same time, avoiding the intermittent feeding and discharging production mode, maximizing the equipment utilization rate and greatly improving the production efficiency.

[0041] The method of the invention solves the traditional problem of "difficult treatment of ferric chloride etching waste liquid and large increment", processes the waste etching liquid online to achieve recycling, can quickly and effectively regenerate the ferric chloride etching liquid, can reduce the use of oxidants, and does not generate dangerous gas chlorine during the regeneration process, can meet low-acidity production, effectively reduce hydrochloric acid mist in the workshop, can reduce production costs while not generating waste etching liquid, and realizes online recycling regeneration of ferric chloride etching waste liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The schematic diagram of the structure of the ferric chloride etching solution regeneration system of the present invention. DETAILED DESCRIPTION

[0043] The technical solution will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] A ferric chloride etching solution recycling system, characterized in that it comprises a stirring tank 1, an iron powder bin 11 is provided above the stirring tank, one end of the iron powder bin is connected to an iron powder feed end 13; one side of the stirring tank is connected to an etching line discharge end 14;

[0046] A first centrifugal pump 2 is connected below the stirring tank, the first centrifugal pump is provided with a sponge copper discharge end 21, and the first centrifugal pump is connected to a first filtrate tank 3;

[0047] It also includes an integrated reactor 4 and a second centrifugal pump 7, wherein the integrated reactor is connected to the first filtrate tank and the second centrifugal pump respectively;

[0048] The second centrifugal pump is provided with a hydroxy iron discharge end 71 , and the second centrifugal pump is connected to a second filtrate tank 8 , and a heat exchanger 9 is connected to one side of the second filtrate tank.

[0049] Furthermore, the second filtrate tank is connected to a hydrochloric acid inlet 81; the heat exchanger is provided with a cooling water inlet 91 and a regeneration product discharge 92 respectively.

[0050] Furthermore, a stirring paddle 12 is provided in the stirring tank.

[0051] Example 2

[0052] This embodiment provides a ferric chloride etching solution regeneration system that is the same as that of Embodiment 1, except that, further, the integrated reactor is an integrated secondary oxidation reactor.

[0053] Furthermore, the integrated reactor includes a body 40, a first ejector 5, a second ejector 6, an exhaust pipe 43, a first circulation pump 41, and a second circulation pump 42; a port on the top of the body is connected to a pressure gauge (not marked); the middle area of ​​the top of the body is connected to the lower port of the first ejector, and the right side of the first ejector is connected to the exhaust pipe; the left side of the top of the body is connected to the lower port of the second ejector, and the right side of the second ejector is connected to another port on the left side of the top of the body; an oxygen feed end 44 is provided on the left side of the bottom of the body; a thermometer (not marked) is connected to the right side of the bottom of the body; the middle area of ​​the bottom of the body is connected to the first circulation pump, the middle side of the body is connected to the second circulation pump, the first circulation pump is connected to the upper port of the first ejector, and the second circulation pump is connected to the upper port of the second ejector; an exhaust gas outlet end 45 is provided on the upper part of the body.

[0054] Example 3

[0055] A method for recycling ferric chloride etching solution, characterized in that it comprises the recycling system of embodiment 1; comprising the following steps:

[0056] Step S110, continuously conveying the copper-containing ferric chloride etching waste liquid of the etching line to a two-stage integrated stirring tank, controlling the liquid level of the stirring tank at 60% of the effective volume, continuously adding an appropriate amount of iron powder, so that all the FeCl3 remaining in the ferric chloride etching waste liquid is reduced to FeCl2, and the copper ions are replaced by elemental copper, controlling the ORP to be stable within a certain range, ensuring that the copper content in the etching waste liquid is less than 10g / L, and the stirring tank is at normal pressure and the reaction temperature is 80-90°C;

[0057] In one embodiment, the raw material liquid contains 5%-6% copper, 7%-9% iron in the copper-containing ferric chloride etching waste liquid, and 95% iron in the iron powder. The raw material liquid is discharged from the etching line to the stirring tank, and the iron powder is continuously added to the stirring tank by a vacuum suction machine. The raw material and the iron powder are contacted and mixed to produce a chemical reaction, and flow from the first level of the stirring tank to the bottom of the second level. At this time, the ORP is less than or equal to 100mv, and the material is continuously fed and discharged and the iron powder is continuously added. If the subsequent ORP>100mv, the amount of iron powder added is increased; if the ORP<100mv, the amount of iron powder added is reduced.

[0058] Step S120, using a centrifugal pump to pump the bottom material in the stirring tank to a separator for solid-liquid separation, separating the copper powder and ferrous water in the material, and the separated ferrous water enters a subsequent integrated reactor through a pipeline for oxygen oxidation treatment;

[0059] In one embodiment, the material in the stirring tank contains 6% solid copper and the ferrous water contains 8% iron. The copper powder is filtered out through a solid-liquid separator, and the filtrate is continuously transported to the first stage of the integrated reactor through a delivery pump.

[0060] Step S130, ferrous water is continuously fed into the first-stage reactor of the integrated reactor, and oxygen oxidant is introduced from the bottom of the second stage of the multi-stage reactor, so that the system pressure of the integrated reactor is 0.15MPa and the reaction temperature is 80-100°C.

[0061] Oxygen is continuously introduced into the reactor through a pneumatic regulating valve. During the oxidation process, the raw material liquid gradually consumes oxygen. As the oxidation degree of the material increases, its oxygen consumption will gradually decrease, and the system pressure will gradually increase. When the system pressure is less than 0.15MPa, the consumed oxygen is quickly replenished; when the system pressure reaches 0.15MPa, the oxygen regulating valve will adjust the valve opening according to the system pressure to keep the pressure of the reaction system at 0.15MPa; at the same time, a protection pressure of 0.2MPa is set as a control point to cut off the oxygen supply and exhaust gas emission, to avoid safety hazards caused by excessive pressure due to failure of the reaction system. After the exhaust gas is discharged, it is absorbed by liquid alkali until the system pressure drops to 0.15MPa.

[0062] Step S140, the material in the integrated reactor is passed through a circulation pump from the bottom, a part of which circulates itself, and the other part is fed to the next-stage reactor; the material flow rate is controlled so that the divalent iron ions in the material are gradually and completely oxidized through the two-stage reaction, and the mass fraction of divalent iron ions in the discharge of the secondary reactor is controlled to be ≤0.1%.

[0063] In this embodiment, the mixing process of the material and oxygen in the reactor is completed by the interaction of the circulating pump and the ejector. The material in the reactor is pumped into the ejector by the circulating pump, and the ejector forms a vacuum low-pressure extraction of oxygen at the top of the reactor through the high-speed jet of the nozzle, so that it is fully mixed, the contact area of ​​the gas-liquid reaction is increased, and the oxidation reaction is accelerated. After the material is ejected, a part of it is forced to circulate in its own reactor, and the other part enters the next reactor to react until the mass fraction of divalent iron ions in the last reactor is ≤0.1%. By controlling the flow direction of the material, the oxidation degree of the material in the integrated reactor is made to present a certain gradient. For example: in an integrated reactor separating the secondary reactor, the oxidation degree of the material in each reactor is 70% and 30% respectively. For example: a sampling port is set between the reactor and the circulating pump, and the current oxidation degree is judged by detecting the mass fraction of divalent iron ions in each reactor, and then the flow rate of the material is regulated to meet the requirements of the oxidation degree.

[0064] Step S150, the lack of acid during the oxidation process in the integrated reactor causes hydrolysis to produce by-products of solid hydroxy iron and ferric chloride, and the discharge from the secondary reactor is separated by a centrifuge to obtain solid hydroxy iron and liquid ferric chloride.

[0065] In this embodiment, the oxidation process of the oxidation kettle material is hydrolyzed to produce solid hydroxy iron due to the lack of acid, thereby reducing the iron content in the material and taking away the moisture in the added hydrochloric acid, ensuring that the content of the regenerated ferric chloride solution remains unchanged and increases.

[0066] Step S160, the liquid ferric chloride separated from the integrated reactor is continuously supplemented with a certain amount of hydrochloric acid and heat-exchanged to 50-55°C before returning to the etching line for etching.

[0067] In this embodiment, the liquid ferric chloride separated from the integrated reactor is continuously supplemented with a certain amount of hydrochloric acid for heat exchange. The added hydrochloric acid is used to maintain the chlorine carried away by the by-product. The ferric chloride is cooled to 50-55 degrees through heat exchange to meet the production requirements of the etching line.

[0068] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0069] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. It should be noted that the technical features not described in detail in the present invention can be realized by any existing technology.

Claims

1. A ferric chloride etching solution recycling system, characterized in that: It comprises a stirring tank, an iron powder bin is arranged above the stirring tank, one end of the iron powder bin is connected to an iron powder feeding end; one side of the stirring tank is connected to an etching line discharging end; A first centrifugal pump is connected below the stirring tank, the first centrifugal pump is provided with a sponge copper discharge end, and the first centrifugal pump is connected to a first filtrate tank; the separated ferrous water enters the integrated reactor through a pipeline for oxygen oxidation treatment; It also includes an integrated reactor and a second centrifugal pump, and the integrated reactor is connected to the first filtrate tank and the second centrifugal pump respectively; the integrated reactor is an integrated secondary oxidation reactor; the integrated reactor includes a body, a first ejector, a second ejector, an exhaust pipe, a first circulation pump, and a second circulation pump; a port on the top of the body is connected to a pressure gauge; the middle area on the top of the body is connected to the lower port of the first ejector, and the right side of the first ejector is connected to the exhaust pipe; the left side of the top of the body is connected to the lower port of the second ejector, and the right side of the second ejector is connected to another port on the left side of the top of the body; an oxygen feed end is provided on the left side of the bottom of the body; a thermometer is connected to the right side of the bottom of the body; the middle area at the bottom of the body is connected to the first circulation pump, the middle side of the body is connected to the second circulation pump, the first circulation pump is connected to the upper port of the first ejector, and the second circulation pump is connected to the upper port of the second ejector; a tail gas outlet is provided on the upper part of the body; the lack of acid in the oxidation process of the integrated reactor leads to hydrolysis to produce byproducts of solid hydroxy iron and ferric chloride, and the discharge of the secondary reactor is separated by a centrifuge to obtain solid hydroxy iron and liquid ferric chloride; The second centrifugal pump is provided with a hydroxy iron discharge end, the second centrifugal pump is connected to a second filtrate tank, and one side of the second filtrate tank is connected to a heat exchanger.

2. The ferric chloride etching solution recycling system according to claim 1, characterized in that: The second filtrate tank is connected to a hydrochloric acid inlet end; the heat exchanger is respectively provided with a cooling water inlet end and a regeneration product discharge end.

3. The ferric chloride etching solution recycling system according to claim 2, characterized in that: A stirring paddle is arranged in the stirring tank.

4. A method for regenerating ferric chloride etching solution, characterized in that: The recycling system according to claim 3 comprises the following steps: A. Continuously convey the copper-containing ferric chloride etching waste liquid of the etching line into the stirring tank, control the liquid level of the stirring tank at 40-70% of the effective volume, continuously add an appropriate amount of iron powder, so that the remaining FeCl3 in the ferric chloride etching waste liquid is completely reduced to FeCl2, and the copper ions are replaced by elemental copper, control the ORP to be stable within a certain range, ensure that the copper content in the etching waste liquid is less than 8-12g / L, maintain normal pressure, and control the reaction temperature to 80-90°C; B. Use the first centrifugal pump to separate the solid-liquid separation of the bottom material in the stirring tank, separate the copper powder and ferrous water in the material, and the separated ferrous water enters the subsequent integrated reactor through a pipeline for oxygen oxidation treatment; C. The material in the integrated reactor is pumped from the bottom by the first circulation pump, with one part of the material circulating by itself and the other part feeding the next reactor; the material flow rate is controlled so that the divalent iron ions in the material are gradually and completely oxidized through the two-stage reaction, and the mass fraction of divalent iron ions discharged from the secondary reactor is controlled to be ≤0.1-0.5%; D. The lack of acid during the oxidation process in the integrated reactor causes hydrolysis to produce byproducts of solid hydroxy iron and ferric chloride. After the secondary reaction, the discharge is separated by the second centrifuge to obtain solid hydroxy iron and liquid ferric chloride; E. The liquid ferric chloride separated from the integrated reactor is continuously supplemented with a certain amount of hydrochloric acid for heat exchange to 50-55°C and then returned to the etching line for etching.

5. The ferric chloride etching solution regeneration method according to claim 4, characterized in that: In step A, when the ORP of the material discharged from the stirring tank is less than 100mV, iron powder is automatically added.

6. The ferric chloride etching solution regeneration method according to claim 4, characterized in that: In step C, molten iron is continuously fed into the primary reactor of the integrated reactor, and oxygen is introduced from the bottom of the secondary reactor, so that the system pressure of the integrated reactor is 0.1-0.3 MPa and the reaction temperature is 80-100°C.

7. The ferric chloride etching solution regeneration method according to claim 6, characterized in that: In step C, in the integrated reactor, after the primary reaction, the oxidation degree of the material is 60-80%; after the secondary reaction, the oxidation degree of the material is 20-40%.

8. The ferric chloride etching solution regeneration method according to claim 4, characterized in that: In step E, the integrated reactor is discharged to the etching line, specifically, cold water is introduced into the discharge heat exchanger for heat exchange, so that the reaction temperature of the material is 50-55°C.

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