CN111032917A

CN111032917A - Ammonia distillation recycling process and system for alkaline etching waste liquid of circuit board

Info

Publication number: CN111032917A
Application number: CN201880035101.9A
Authority: CN
Inventors: 叶涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-07-05
Filing date: 2018-07-05
Publication date: 2020-04-17
Anticipated expiration: 2038-07-05
Also published as: WO2019007407A1; CN111032917B; CN108149249A

Abstract

A process for recycling ammonia distillation of alkaline etching waste liquid of a circuit board comprises the steps of heating the alkaline etching waste liquid, and collecting gas generated in the heating process to obtain waste liquid gas; when the etching waste liquid is heated until a precipitate is separated out, a solid-liquid mixture A1 is obtained; mixing the solid-liquid mixture A1 with hydrochloric acid and/or acidic etching waste liquid and adjusting the pH, and separating insoluble precipitate from other soluble components; obtaining mixed solution A2; mixing the waste liquid gas with carbon dioxide to generate ammonium carbonate and/or ammonium bicarbonate; adding ammonium carbonate and/or ammonium bicarbonate into the mixed solution A2 and supplementing other components required by the etching process to obtain a recycled etching solution, wherein foreign substances which are bad for etching are not brought in the treatment process, so that the recycling can be realized, the production cost can be effectively reduced, and the problem of ammonia nitrogen pollution brought by the traditional alkaline copper chloride ammonium etching waste liquid extraction and recovery process is solved; also discloses an ammonia distillation recovery and circulation process system for the alkaline etching waste liquid of the circuit board.

Description

Ammonia distillation recycling process and system for alkaline etching waste liquid of circuit board

Technical Field

The invention relates to the field of waste etching solution recycling, in particular to an ammonia distillation recycling process for alkaline waste etching solution of a circuit board.

Background

Etching is an important step in the existing Printed Circuit Board (PCB) manufacturing process. Etching is to remove unnecessary copper on the copper-clad substrate by chemical reaction with an etching solution to form a desired circuit pattern.

The commonly used etching solution at present comprises acidic copper chloride and alkaline ammonium copper chloride, wherein:

the acidic copper chloride etching solution mainly comprises the following components: copper salts, hydrochloric acid, sodium chloride or ammonium chloride, water, and optionally additives.

The main components of the alkaline ammonium copper chloride etching solution are copper salt, ammonium chloride, ammonia water, optional carbonate and optional additives; among them, ammonium carbonate and ammonium bicarbonate are generally used as the carbonate. When a PCB is etched using an alkaline ammonium copper chloride etchant, the etchant is usually added to maintain a concentration balance of the components during the etching process. The main components of the etching sub-solution are ammonium chloride, ammonia water, optional carbonate and optional additives.

The optional additives in the etching solution and the etching sub-solution refer to some optional additives which have certain optimization effect on the performance of the etching solution (such as changing reaction balance and reaction rate) and do not change main chemical reaction generated in the etching process. Such as stabilizers, accelerators, and the like.

The following reaction occurs when etching is performed using basic ammonium copper chloride:

Cu(NH₃)₄Cl₂+Cu→2Cu(NH₃)₂Cl

4Cu(NH₃)₂Cl+4NH₄Cl+4NH₄OH+O₂→4Cu(NH₃)₄Cl₂+6H₂O

since the alkaline ammonium copper chloride etching solution reacts continuously during the etching process, the components of the etching solution are consumed continuously, and the concentration of the components of the etching solution changes continuously, and generally, the component content of the etching sub-solution is slightly higher than the concentration of the corresponding components in the etching solution. The concentration of copper ions is required to be controlled within 30-180g/l and the pH value is required to be within 7-9 in the etching process, so that the component content in the etching solution is required to be continuously detected by an automatic detection feeding control machine in the production process, and the etching solution and/or the supplemented ammonia water are added according to the detection condition.

In the actual production, in order to keep the components of the etching solution stable, the etching solution in the etching tank is inevitably increased and overflows out of the etching tank because the etching solution and/or the ammonia water are required to be continuously added; the etching solution overflowing out of the etching bath or the used etching solution is generally called as etching waste solution, the main components of the alkaline ammonium copper chloride etching waste solution comprise ammonium copper chloride, cuprous ammonium chloride, ammonium chloride and ammonia water, and some alkaline etching waste solutions also contain ammonium carbonate, ammonium bicarbonate, organic ammonium salt, organic amine and the like.

The following three common treatment methods for alkaline etching waste liquid exist at present:

an acidification electrolysis method: carrying out acidification reaction on the alkaline etching waste liquid by using hydrochloric acid and/or acidic copper chloride etching waste liquid to generate precipitate and supernatant; the separated precipitate is dissolved by sulfuric acid to prepare copper sulfate or electrolyzed to prepare refined copper, and the supernatant and the copper sulfate-containing residual liquid generated in the copper sulfate preparation process are subjected to evaporation concentration after further copper removal to obtain the mixed ammonium salt. The main components of the existing acidic copper chloride etching waste liquid generally comprise hydrochloric acid, copper chloride, cuprous chloride and water.

The method has the disadvantages that sulfuric acid is used in the recovery treatment process, sulfate radicals which have aggressive corrosivity to an etching resisting layer are introduced, and the produced mixed ammonium salt can not be reused in the etching process; and the energy consumption for preparing the mixed ammonium salt by applying the evaporation and concentration process is large.

An alkalization method: and adding a sodium hydroxide solution into the alkaline etching waste liquid, and heating to obtain copper oxide precipitate. Then dissolving the copper oxide precipitate with sulfuric acid to obtain copper sulfate, and absorbing the ammonia gas escaped in the heating process with water to obtain ammonia water for recycling. The residual liquid is treated to reach the discharge standard before being discharged.

The method has the defects of large wastewater treatment capacity and high treatment cost after the copper oxide and the ammonia water are recovered.

An extraction electrolysis method: after the alkaline etching waste liquid and the organic extractant are mixed and phase-separated, the sulfuric acid is used for back extraction to obtain copper sulfate, and the copper sulfate solution is electrolyzed to obtain the refined copper. Part of the waste liquid after the phase separation treatment can be prepared into etching solution again for recycling.

The method uses the organic extractant in the recovery process, and has the defects that when the etching solution is recovered and recycled to prepare the etching solution again, a small amount of the organic extractant is mixed every time, and the indexes of the etching rate and the quality are reduced after accumulation. In addition, the extraction agent process causes ammonia nitrogen pollution in the recovery process, and the treatment cost is higher.

The ammonia nitrogen pollutants are very easy to dissolve in water, the ammonia nitrogen content index in the water body is an important index of water body eutrophication, once the water body is eutrophicated, algae in the water body are very easy to propagate massively to explode red tide and water bloom, on one hand, the oxygen content of the water body is reduced, and other organisms (fish, shrimp, crab and the like) in the water body die due to oxygen deficiency, so that the water body is polluted; on the other hand, the accumulation of toxins produced by toxic algae can directly cause water body pollution.

In summary, although the existing three treatment methods for alkaline etching waste liquid can recover copper sulfate, refined copper, ammonium salt or ammonia water from the waste liquid, some of the treatment methods can also make the alkaline etching waste liquid re-prepared into etching sub-liquid for recycling, in the process of recycling the alkaline etching waste liquid, foreign substances which are bad for etching can be brought in, the indexes of etching rate and quality are affected, and the problem of ammonia nitrogen pollution is brought, or the treatment cost is high, no treatment method can recycle the alkaline etching waste liquid well, the production cost can be effectively reduced, and the problem of ammonia nitrogen pollution brought by the traditional alkaline ammonium copper chloride extraction electrolysis recovery process can be solved.

Disclosure of Invention

The invention aims to provide an ammonia distillation recovery and circulation process for alkaline etching waste liquid of a circuit board, which not only can recover and recycle the alkaline etching waste liquid, but also can keep the normal etching rate and quality index of the recycled etching sub-liquid obtained by recovery; and the problem of ammonia nitrogen pollution can not be caused.

The purpose of the invention can be realized by adopting the following technical scheme:

an ammonia distillation recycling process for alkaline etching waste liquid of a circuit board comprises the following steps:

(1) gas-liquid separation of etching waste liquid: heating the alkaline etching waste liquid with the copper ion concentration of 30-180g/L, pH value of 7-9, collecting gas generated in the heating process, and obtaining waste liquid distilled gas A; when the etching waste liquid is heated until a precipitate is separated out, a solid-liquid mixture A1 is obtained;

(2) adjusting the pH value: mixing the solid-liquid mixture A1 obtained in the step (1) with hydrochloric acid and/or acidic etching waste liquid, adjusting the pH value to 3-6, further increasing precipitates in the solid-liquid mixture A1, separating the precipitates in the obtained solid-liquid mixture A1, and respectively obtaining solid precipitates and a mixed solution A2 after solid-liquid separation;

(3) and (3) gas treatment: mixing the waste liquid distilled gas A collected in the step (1) with carbon dioxide to generate ammonium carbonate and/or ammonium bicarbonate;

(4) mixing the solution: adding ammonium carbonate and/or ammonium bicarbonate into the mixed solution A2 obtained in the step 2 to obtain a mixed solution A3;

(5) and (4) regeneration of the etching sub-solution, namely supplementing other required components of the etching process in the mixed solution A3 obtained in the step ⑷ to obtain the recycled etching sub-solution.

In the heating process of the step (1), the generated gas comprises ammonia gas, water vapor and carbon dioxide which may be generated; the ammonia gas is derived from ammonia water volatilization contained in the etching waste liquid and decomposition or hydrolysis reaction of ammonium carbonate, ammonium bicarbonate, organic amine, organic ammonium and other components contained in part of alkaline etching liquid. The carbon dioxide comes from the decomposition reaction of ammonium carbonate and/or ammonium bicarbonate contained in the etching waste liquid by heating; the water vapor is derived from the evaporation of liquid water;

see in particular the chemical reaction formulae below.

The chemical reaction that takes place in step (1) is as follows:

volatilization reaction of ammonia water: NH (NH)₄OH→H₂O+NH₃↑

Thermal decomposition reaction of ammonium carbonate: (NH)₄)₂CO₃→2NH₃↑+CO₂+H₂O

Thermal decomposition reaction of ammonium bicarbonate: NH (NH)₄HCO₃→NH₃↑+CO₂+H₂O

Thermal decomposition reaction of organic ammonium salt: R-NH₄→NH₃↑+R-H

And (3) carrying out a heated hydrolysis reaction on organic amine: R-NH₂+H₂O→NH₃↑+R-OH

The main components of the solid-liquid mixture A1 in the step (1) comprise cupric ammonium chloride, cuprous ammonium chloride, ammonia water, basic cupric chloride and cupric hydroxide. Wherein, the cupric ammonium chloride, cuprous ammonium chloride, ammonium chloride and ammonia water are the original main components of the alkaline etching waste liquid, and the basic cupric chloride and the cupric hydroxide are from the sources, because the cupric chloride is soluble only in the acidity, and becomes the basic cupric chloride Cu when becoming neutral or alkaline along with the reduction of the acidity₂(OH)₂Cl₂And/or copper hydroxide Cu (OH)₂While the ammonia is insoluble in water, the nitrogen atom of the ammonia has a lone electron pair which can be in the form of water moleculesHydrogen bonds, so that the copper of the copper chloride and NH3 form the complex copper chloride ammonia Cu (NH)₃)₄Cl₂When dissolved in water. Therefore, in the step 1, since part of the ammonia gas and part of the water in the solution are evaporated as one of the components of the gas a, the solution does not have enough ammonia to complex with the copper chloride, and the water as the solvent is reduced, so that the precipitate of copper oxychloride and/or copper hydroxide occurs, and the solid-liquid mixture a1 is obtained:

2Cu(NH₃)₄Cl₂+2H₂O→Cu₂(OH)₂Cl₂+2NH₄Cl+6NH₃↑

Cu(NH₃)₄Cl₂+2H₂O→Cu(OH)₂+2NH₄Cl+2NH₃↑

the main chemical equation of the reaction of the solid-liquid mixture A1 and hydrochloric acid in the step (2) is as follows:

2Cu(NH₃)₄Cl₂+2HCl+2H₂O→Cu₂(OH)₂Cl₂↓+4NH₄Cl

4Cu(NH₃)₂Cl+8HCl+4H₂O+O₂→2Cu₂(OH)₂Cl₂↓+8NH₄Cl+2H₂O

2Cu(OH)₂+2HCl→Cu₂(OH)₂Cl₂↓+2H₂O

NH₄OH+HCl→NH₄Cl+H2O

Cu₂(OH)₂Cl₂+4HCl→2CuCl₂+4H₂O

from the above reaction formulae, in the present invention, when the solid-liquid mixture a1 is reacted with hydrochloric acid alone, the mixed solution a2 in the step (2) contains ammonium chloride and water as main components, and may contain copper chloride formed by the reaction with sufficient hydrochloric acid and residual unreacted copper ammonium chloride, cuprous ammonium chloride, and hydrochloric acid.

On the other hand, in the step (2), if the solid-liquid mixture a1 reacts only with the acidic etching waste liquid, since the acidic etching waste liquid is a waste liquid generated after the etching operation of the acidic copper chloride etching liquid and contains hydrochloric acid, copper chloride, cuprous chloride and water as main components, the following reactions occur in addition to the reaction of each of ammonium cupric chloride, ammonium cuprous chloride, aqueous ammonia and copper hydroxide in the solid-liquid mixture a1 with hydrochloric acid in the acidic etching waste liquid:

Cu(OH)₂+CuCl₂→Cu₂(OH)₂Cl₂↓

4NH₄OH+CuCl₂→Cu(NH₃)₄Cl₂+4H₂O

Cu₂Cl₂+4NH₄OH→2Cu(NH₃)₂Cl+4H₂O

therefore, when the solid-liquid mixture a1 reacts with the acidic etching waste liquid, the mixed solution a2 described in step (2) contains ammonium chloride and water as main components, and may contain ammonium cupric chloride, ammonium cuprous chloride, cupric chloride, cuprous chloride, and hydrochloric acid.

The solid precipitate separated in the step (2) mainly comprises basic copper chloride and/or copper hydroxide, and may also contain ammonium chloride which is not dissolved due to insufficient water in the solid-liquid mixture A1, and can be washed to form basic copper chloride and/or copper hydroxide for packaging and sale, or can be mixed with a sodium hydroxide solution and heated to form a copper oxide product for sale.

In the step (3) of the present invention, the ammonia gas in the gas reacts with the carbon dioxide and the water vapor as follows:

2NH₃+CO₂+H₂O→(NH₄)₂CO₃

NH₃+CO₂+H₂O→NH₄HCO₃

the carbon dioxide in the step (3) of the present invention may be ammonium carbonate or ammonium bicarbonate which is derived from the thermal decomposition of the etching waste liquid in the step (1), may be an additional carbon dioxide gas, or may be a combination of the two.

The ammonium carbonate and/or ammonium bicarbonate added in the step (4) in the invention in the A2 can be purchased, or can be derived from the ammonium carbonate and/or ammonium bicarbonate obtained in the step (3), or can be a combination of the ammonium carbonate and the ammonium bicarbonate; the obtained mixed solution a3 mainly contains the following components: cupric ammonium chloride, cuprous ammonium chloride, ammonium carbonate, and/or ammonium bicarbonate.

The invention utilizes the characteristic that ammonium carbonate and ammonium bicarbonate are decomposed by heat to generate ammonia, and takes the ammonium carbonate and/or the ammonium bicarbonate as etched NH₄ ⁺Dissolving the source, preferably ammonium carbonate and ammonium bicarbonate obtained from the step (3), in the mixed solution A2 to prepare the etching sub-solution for recycling, and effectively providing NH in the etching process₄ ⁺And the amount of extra added ammonia water is reduced. Therefore, the volume of the recycled etching sub-liquid obtained after the recycling treatment is ensured not to be larger than the supplement addition amount of the etching sub-liquid required by etching production, and the problem that the recycled etching sub-liquid cannot be consumed due to too much residual amount in the recycling process is avoided.

Supplementing other required components of the etching process in the mixed solution A3 in the step (5) of the invention means supplementing ammonium chloride, ammonia water, optional carbonate and optional additives which are contained in the original etching sub-solution, but are consumed by reaction in the etching process and are not regenerated or insufficient in regeneration amount in the recovery process, so that the ammonium ion concentration, the ammonium chloride concentration and the optional additive concentration of the etching sub-solution which is recycled are not lower than the ammonium ion concentration, the ammonium chloride concentration and the optional additive concentration of the etching sub-solution when an etching waste solution recovery system is not used; wherein the supplemented ammonia water can be replaced by ammonium carbonate and/or ammonium bicarbonate as long as NH is maintained⁴⁺The ion concentration is equivalent.

The make-up amounts of other required components of the etching process described in step (5) of the present invention can be determined by calculation after detecting the ammonium ion concentration, the ammonium chloride concentration, and the optional additive concentration, or can be determined based on empirical data.

The etching solution recycled in the step (5) can partially or completely replace the etching solution prepared from the raw materials, and is supplemented into the etching solution in the etching operation process to form the recycling of the etching solution, so that the cost of etching production can be greatly reduced. The etching solution is added in the production process by automatically detecting the pH value and/or specific gravity parameter value of the etching solution through an automatic detection feeding control machine on the production line, and automatically controlling the feeding of the etching solution for recycling according to a set value.

The invention can be further improved as follows:

in order to better recycle the etching waste liquid, when the mixed solution A2 is used to dissolve the ammonium carbonate and/or ammonium bicarbonate obtained in the step (3) in the step (4), the mixed solution A2 obtained by filtering in the step (2) can be directly used for washing and dissolving the ammonium carbonate and/or ammonium bicarbonate, namely, the mixed solution A2 is directly used for washing a production container of the ammonium carbonate and/or ammonium bicarbonate to carry the ammonium carbonate and/or ammonium bicarbonate away, and then the step (5) is carried out.

As can be seen from the ammonia and carbon dioxide reaction equations, when the concentration of the carbon dioxide species is less than the concentration of the ammonia species, the reaction equilibrium will tend to produce ammonium carbonate, and conversely, the reaction equilibrium will tend to produce ammonium bicarbonate, and different ratios of the concentrations of the species are set to control the amounts of ammonium carbonate and ammonium bicarbonate produced, so that in step (3), the gas reaction can be divided into two parts, ① to make the first part of the ammonia species have a concentration greater than the concentration of the carbon dioxide species, and ② to make the second part of the ammonia species have a concentration less than the concentration of the carbon dioxide species, so as to control the ratio of ammonium carbonate and ammonium bicarbonate produced.

In order to better recycle the etching waste liquid, in the step (3), the tail gas of the synthesis reaction of the ammonium carbonate and/or the ammonium bicarbonate can be collected by a jet device, the liquid using water as jet flow absorbs the tail gas of the synthesis reaction of the waste liquid gas and the carbon dioxide to generate the ammonium carbonate and/or the ammonium bicarbonate, and the ammonium carbonate and/or the ammonium bicarbonate aqueous solution recovered in the jet device can be reused for preparing the etching sub-liquid.

In order to better recycle the etching waste liquid, in the step (3), a jet device is adopted to use water as jet liquid to absorb tail gas of the synthesis reaction of ammonium carbonate and/or ammonium bicarbonate to obtain aqueous solution, and a pH meter is adopted to detect the pH value of the aqueous solution obtained in the jet device; when the aqueous solution is detected to be alkaline, the amount of carbon dioxide in the synthesis reaction of ammonium carbonate and/or ammonium bicarbonate is appropriately increased; otherwise, the amount of carbon dioxide is appropriately reduced.

To facilitate the escape of gas from the mixing location, collection is facilitated. In the step (1), a stirring device can be used in the heating process.

In order to accelerate the gas-liquid separation of the etching waste liquid in the step (1), an external pressurized air insertion pipe is arranged on the heating container and is opened during and/or after the heating process is finished. The external pressurized air insertion pipe comprises a pipeline and a pump which are communicated with the heating container and the outside.

And (3) opening the external pressurized air insertion pipe in the heating process, pumping air outside the heating container into the heating container through the external pressurized air insertion pipe, stirring the alkaline etching waste liquid in the heating container, promoting the waste liquid to volatilize gas, and enabling the volatilized gas to rapidly enter the step (3) for synthesis reaction.

And after the heating process is finished, the external pressurized air insertion pipe is opened, so that the air outside the heating container can be pumped into the heating container through the external pressurized air insertion pipe, and the temperature of the mixture in the heating container is reduced at an accelerated speed while stirring, so that the next step is carried out as soon as possible.

Preferably, in the heating of the etching waste liquid in the step (1), the heating temperature may range from 30 ℃ to the boiling temperature of the waste liquid.

The second object of the present invention can be solved by the following technical solutions:

a system for recovering and circulating ammonia from alkaline etching waste liquor of a circuit board comprises the following components:

at least one acid-base adjusting tank for adjusting the pH value of the residual liquid after the alkaline etching waste liquid is evaporated;

at least one heating evaporation tank which consists of a heating tank body, a heating device arranged inside and/or outside the heating tank body and an air outlet; for concentrating and heating the alkaline etching waste liquid and separating the waste liquid gas;

at least one combination reaction tank which is composed of a reaction tank body, and a carbon dioxide inlet and a waste liquid gas inlet which are arranged on the reaction tank body; the carbon dioxide inlet is connected with a carbon dioxide source, the waste liquid gas inlet is connected with the gas outlet of the heating evaporation tank, and the waste liquid gas inlet is used for producing ammonium carbonate and/or ammonium bicarbonate;

the device comprises at least one filter, a liquid-solid separation device and a liquid-solid separation device, wherein the filter is used for separating solid and liquid in a solid-liquid mixture, an inlet of the filter is connected with an acid-base adjusting tank, and a liquid outlet of the filter is connected with a sub-liquid adjusting tank or a chemical combination reaction tank;

and at least one sub-solution preparation tank for preparing the circularly regenerated etching sub-solution.

The invention can also be improved as follows:

and a stirring device is arranged in the heating evaporation tank, and is used for stirring the heated alkaline etching waste liquid so as to promote the gas to escape from a stirring position.

The heating evaporation tank is provided with an external pressurized air insertion pipe, the external pressurized air insertion pipe is composed of a pipeline and a pump which are communicated with the inside of the heating evaporation tank and the outside, and is used for pumping air into the alkaline etching waste liquid, stirring the alkaline etching waste liquid, promoting the waste liquid to volatilize gas, and enabling the volatilized gas to rapidly enter the step (3) for synthesis reaction.

Preferably, a pump is arranged on a pipeline connecting the heating evaporation tank and the chemical combination reaction tank and/or an air outlet of the chemical combination reaction tank.

The invention can also be provided with an additional air outlet and/or an additional liquid inlet and/or a discharging port on the combination reaction tank. One of the additional gas outlets functions as a gas outlet when the combination reaction tank and the other combination reaction tank or the jet device are connected with each other; and the other function is to effectively prevent potential safety hazard caused by overlarge air pressure in the chemical combination reaction tank. The additional liquid inlet is an inlet for the mixed solution A2 to enter the combination reaction tank after passing through the filter, and in addition, when the ammonium carbonate and/or ammonium bicarbonate obtained in the step 3 is added into the mixed solution A2, the mixed solution A2 can be fed into the combination reaction tank through the filter, at the moment, because the preparation of the ammonium carbonate and/or ammonium bicarbonate in the combination reaction tank is completed, the carbon dioxide inlet and/or the waste liquid gas inlet of the combination reaction tank can also be directly used as the liquid inlet of the A2.

The discharge port is an outlet for conveying ammonium carbonate and/or ammonium bicarbonate in the combination reaction tank to the sub-liquid preparation tank (whether the mixed solution A2 passes through the combination reaction tank or not is not considered at this time, and the discharge port is required for conveying the ammonium carbonate and/or the ammonium bicarbonate no matter the mixed solution A2 does not pass through the combination reaction tank or the mixed solution A2 is not sufficient to wash and dissolve the ammonium carbonate and/or the ammonium bicarbonate). Since the preparation of ammonium carbonate and/or ammonium bicarbonate is completed when ammonium carbonate and/or ammonium bicarbonate is sent out of the combination reaction tank, the carbon dioxide inlet and/or the waste liquid gas inlet of the combination reaction tank can be directly used as the discharge port.

More preferably, a heating device is arranged near the carbon dioxide inlet and/or the waste liquid gas inlet and/or the liquid inlet of the chemical combination reaction tank, so that the position can be kept at a higher temperature, and the generation speed of solid ammonium carbonate and/or ammonium bicarbonate at the position can be effectively inhibited to avoid blocking the inlet.

Preferably, the chemical combination reaction tank is connected with a jet device;

the jet flow vacuum device is provided with a gas-liquid mixing cavity and a collecting cylinder, and water is stored in the collecting cylinder and is used for dissolving tail gas of the chemical combination reaction tank; the gas-liquid mixing cavity is respectively provided with a jet air suction port, a jet liquid inlet and a jet liquid outlet, and the jet liquid outlet extends into the collecting cylinder through a liquid outlet pipe; the jet liquid inlet is connected with the collecting cylinder through an absorption liquid circulating pipe and a liquid inlet pump arranged on the pipeline. The jet device can be used for absorbing the aqueous solution of the tail gas of the synthesis reaction of ammonium carbonate and/or ammonium bicarbonate to prepare the circularly regenerated etching sub-solution in the sub-solution preparation tank.

Preferably, a pH meter is arranged in the collecting cylinder of the fluidic device and is used for detecting the pH value of the liquid in the collecting cylinder.

The invention has the beneficial effects that:

1) in the process of treating the alkaline ammonium copper chloride etching waste liquid, no new impurities such as acid radical ions and the like are introduced, and no organic extractant is contained, so that the alkaline ammonium copper chloride etching waste liquid is recycled, the etching waste liquid is recycled into the etching sub-liquid, and the etching sub-liquid is recycled in the etching process.

2) The recycled etching solution obtained by recycling does not contain an organic extractant, so that not only can the normal etching rate and quality index be maintained, but also ammonia nitrogen pollution is avoided.

3) The invention uses NH in the alkaline ammonium copper chloride etching waste liquid⁴⁺The quality requirement can be met without or only by adding a small amount of ammonia water when preparing the etching solution for recycling, so that the volume change of the etching solution is extremely small, a large amount of residual etching solution can not be generated in the using process, the amount of the etching solution overflowing from the etching tank is reduced, and unnecessary energy consumption is avoided.

4) The invention can recover NH in the alkaline ammonium copper chloride etching waste liquid⁴⁺The problem that ammonia nitrogen pollutants are discharged to the environment by the traditional alkaline copper ammonium chloride etching waste liquid is solved.

Drawings

FIG. 1 is a flow chart of the recycling process of the etching waste liquid in examples 1, 11 and 16 of the present invention;

FIG. 2 is a flow chart of the recycling process of the etching waste liquid in example 2 of the present invention;

FIG. 3 is a flow chart of the recycling process of the etching waste liquid in examples 3, 8, 9, 12, 13 and 20 of the present invention;

FIG. 4 is a flow chart of the recycling process of the waste etching solution in example 4 of the present invention;

FIG. 5 is a flow chart of the recycling process of the etching waste liquid in examples 5, 7, 10, 14, 15, 17 to 19 of the present invention;

FIG. 6 is a flow chart of the recycling process of the etching waste liquid in example 6 of the present invention;

FIG. 7 is a flow chart of the recycling process of the etching waste liquid in example 21 of the present invention.

In the figure, 1 is an acid-base adjusting tank; 2 is a heating evaporation tank; 3 is a combination reaction tank; 4 is a seed liquid preparation groove; 5, a filter; 6 is a jet device; j is alkaline etching waste liquid; c is a precipitate; x is an aqueous solution; y is other required components; z is a circularly regenerated etching solution; 1-1 is a first acid-base adjusting tank; 1-2 is a second acid-base adjusting tank; 2-1 is a first heating evaporation tank; 2-2 is a second heating evaporation tank; 3-1 is a first combination reaction tank: and 3-2 is a second reaction tank.

Detailed Description

The present invention is further described in the following with reference to the drawings and examples so that those skilled in the art can better understand the present invention and can practice it, but the examples are not intended to limit the present invention.

In the following examples and comparative examples, ammonium chloride used was ammonium chloride produced by Guangzhou chemical industries; the ammonia water used is the ammonia water produced by Guangzhou chemical reagent factory; the copper chloride is CuCl produced by Guangzhou chemical reagent factory₂·2H₂O (more than or equal to 99.0%); the ammonium carbonate used is ammonium carbonate produced by Shanghai Hengyuan biological technology limited; the used ammonium bicarbonate is the ammonium bicarbonate produced by Shanghai lanke medicine science and technology development company Limited; the used alkaline etching solution additives are YH-302, YH-303 and YH-304 alkaline etching additives produced by Guangzhou high-chemical industry Co., Ltd; the used automatic detection feeding control machine is a high-chemical industry product of Guangzhou cityIndustrial high PCB alkaline etching automatic feeding machine-2 type (alkaline copper chloride etching system) produced by Limited company; the used alkaline etching waste liquid comes from Guangzhou high chemical industry Co Ltd; the acidic waste etching solution S used is from Guangzhou high chemical industry Co.

In addition to those enumerated above, those skilled in the art can select other products having similar properties to those enumerated above in the present invention according to routine selection, and can achieve the objects of the present invention.

The alkaline etching waste liquid of example 1 was prepared as follows:

step 1: at normal temperature and normal pressure, respectively according to the components specified in the etching solution circularly regenerated in the following table 1, dissolving the selected raw materials in water to prepare the etching solution;

step 2: copper chloride was added per liter of the etchant solution obtained in step 1. The addition amount of copper chloride is calculated according to the set value of the concentration of copper ions in the solution listed in table 1:

wherein the molar mass of the copper chloride is 134.5 g/mol; the molar mass of the copper ions is 63.5 g/mol; according to the values specified in example 1 of Table 1, 190.6g of copper chloride were added per liter of etching bath.

And step 3: pouring the solution obtained in the step (2) into an etching cylinder, and immersing a detection probe for automatically detecting each parameter of the feeding control machine into the etching solution;

and 4, step 4: pouring the etching solution obtained in the step (1) into an etching solution tank connected with a specific gravity meter in an automatic detection and feeding control machine. The temperature of the etching cylinder was set to 50 ℃ and the pressure of the etching solution nozzle of the etching machine was set to 2kg/cm²；

And 5: the etching operation was started, and the automatic detection and feed controller automatically fed the etchant solution to replenish the components in the equilibrium etchant solution so that the specific gravity was maintained at the specific gravity value specified in table 1. In the etching process, the pH value of the etching solution is detected by the automatic detection feeding controller, and the detected value is recorded in the table 1;

step 6: carrying out an etching rate and an etching factor K test on the etching solution, and recording the result in the table 1; the etching working solution after completion of the etching test was used as an alkaline etching waste solution to continue the procedure of the following example.

Etching quality test

An etching factor test circuit board with the size of 620 multiplied by 540mm, the copper thickness of 1oz and the development line width line spacing of 50.8 mu m and a pure copper etching rate test board with the size of 500 multiplied by 300mm multiplied by 1.5mm are put into an etching machine for spray corrosion test, and the etching rate and the etching factor K are calculated by using a method (printed circuit technology, Lexuming, the center for guidance of professional skill identification in the electronic industry of the industry and the informatization department, fifth edition, p 387-389), metallic corrosion theory and application, Weibaoming, chemical industry publishing company, p5-7, shallow etching factor calculation method, Tianling and the like, printed circuit information 2007No.12, p55-56) known in the industry. The results of the calculation of the etching rate and the etching factor K are shown in table 2.

The alkaline etching waste liquid of example 2 was prepared as follows:

the etching solution used in the preparation process of the alkaline etching waste solution of example 2 comprises the following components: 20 wt% of ammonium chloride, 21 wt% of ammonia water, 10 wt% of additive and the balance of water. The pH control parameter of the automatic detection and feeding control machine is 7.2, the specific gravity is controlled to be 1.31g/ml, the copper ion concentration parameter is shown in the following table 1, and the method for preparing the alkaline etching waste liquid in the example 1 is repeated.

The etching quality test was carried out as described for the preparation of alkaline etching waste liquor in example 1.

The contents of the components of the etchant solution in the process of preparing the alkaline etching waste solution of examples 3-20 are the same as the contents of the components of the recycled etchant solution in table 1, and the method for preparing the alkaline etching waste solution of example 1 is repeated with reference to the parameters of the automatic detection batch controller listed in table 1 below.

Example 1

(1) Gas-liquid separation of etching waste liquid: a heating device is arranged in the heating evaporation tank 2, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boiling in the heating evaporation tank 2 for evaporation, and after the alkaline etching waste liquid J is concentrated for 12 hours until precipitates CC can be separated out by naked eyes, a solid-liquid mixture A1 is obtained and is pumped into the acid-base adjustment tank 1; gas escaped in the heating process is collected and introduced into the combination reaction tank 3;

(2) adjusting the pH value: adding hydrochloric acid into an acid-base adjusting tank 1, mixing with a solid-liquid mixture A1 in the tank, adjusting the pH value to 3, and filtering by a filter 5 to obtain a precipitate C and a mixed solution A2, wherein the main component of the precipitate C is solid basic copper chloride;

(3) and (3) gas treatment: adding carbon dioxide compressed gas into the combination reaction tank 3, and under the regulation of the concentration of the carbon dioxide compressed gas, enabling the carbon dioxide concentration in the combination reaction tank 3 to be higher than the ammonia gas concentration for chemical reaction and keeping the molar concentration ratio of the carbon dioxide to the ammonia gas to be about 2:1 to obtain ammonium bicarbonate;

(4) mixing the solution: scraping the ammonium bicarbonate obtained in the step (3) from the chemical reaction tank 3, dissolving the ammonium bicarbonate into an A3 mixed solution by using an A2 solution, draining the mixed solution into a seed solution preparation tank 4, and measuring and calculating the concentration of each component in the A3 mixed solution by using a method known in the industry (measurement of ammonia and carbon dioxide in chemical raw materials ammonium carbonate, plum blossom, metallurgical analysis, Vol.24No.1, p78-79, synthetic hydrochloric acid for GB320-2006 industry, national Standard administration Committee, p2-3, research on chloride ion measurement method and application thereof, Shulingyun, etc., Western leather Vol.31No.15, p32-42) and an additive using a detection method in an instruction book;

⑸ regeneration of etching solution, in the solution preparing tank 4, adding chemical raw materials needed to supplement the mixed solution A3 according to the component proportion of the circular regeneration solution required by the etching process in the table 1, preparing the circular regeneration etching solution, the concentration of copper ions in the A3 mixed solution is not needed to be considered during the preparation, only the concentration of other components is needed to reach the set standard, the same is true for the other embodiments, the prepared circular regeneration etching solution is automatically detected and added on the etching production line by an automatic detection and feeding control machine according to the specific gravity parameter in the table 1, the etching solution is used in the etching process, the etching quality test is carried out according to the method for preparing the alkaline etching waste solution J, and the etching rate and the etching factor K are recorded in the table 1.

Example 2, refer to FIG. 2

(1) Gas-liquid separation of etching waste liquid: heating devices are arranged inside and outside the heating evaporation tank 2, the heating evaporation tank 2 provided with an external pressurized air insertion pipe and a motor-driven stirring device is used for heating the alkaline etching waste liquid J with the parameters in the table 1 to boil for evaporation, the external pressurized air insertion pipe is opened to drive external air into the heating evaporation tank 2 to stir the mixture in the tank, the heating is stopped after the mixture is concentrated for 1 hour until precipitates C are separated out by naked eyes, and the external pressurized air insertion pipe continues to work to accelerate the temperature reduction of the heating evaporation tank 2; obtaining A1 solid-liquid mixture and pumping the solid-liquid mixture into an acid-base adjusting tank 1; the gas escaped in the heating process is collected and introduced into the first combination reaction tank 3;

(2) adjusting the pH value: pouring the A1 solid-liquid mixture and the circuit board acidic etching waste liquid S into an acid-base adjusting tank 1, mixing and adjusting the pH value to 6,

(3) and (3) gas treatment: the first chemical reaction tank 3 is communicated with a second chemical reaction tank 3 which is provided with a jet device 6 for conducting tail gas guiding and collecting treatment; under the regulation of the concentration of the externally added carbon dioxide compressed gas, the ratio of the concentration of the ammonia gas in the first combination reaction tank 3 to the concentration of the carbon dioxide is about 6:1 to obtain ammonium carbonate through reaction, the concentration of the carbon dioxide in the second combination reaction tank 3 is higher than the concentration of the ammonia gas, and the molar concentration ratio of the carbon dioxide to the ammonia gas is kept to be about 1.5:1 to obtain ammonium bicarbonate through reaction; the tail gas of the second combination reaction tank 3 is mixed with water for absorption through a connected jet device 6;

(4) mixing the solution: filtering by a filter 5 to obtain a solid mixture (containing basic copper chloride), and simultaneously flushing the first and second combination reaction tanks 3 by using filtrate A2 by using filtering pressure so as to take the ammonium carbonate and the ammonium bicarbonate obtained in the step (1) out of the tanks to obtain an A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(5) regeneration of etching solution: and (3) adding the aqueous solution X obtained by the jet device 6 in the supplementing step (1) and other required components into the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in the sub-solution preparation tank 4 to prepare the circularly regenerated etching sub-solution Z. The prepared cyclic regeneration etching sub-liquid is automatically detected by an automatic detection feeding control machine according to specific gravity parameters and pH parameters in the table 1 and is fed on an etching production line for etching working procedures, etching quality test is carried out according to the method for preparing the alkaline etching waste liquid J, and the etching rate and the etching factor K are recorded in the table 1.

Example 3, refer to FIG. 3

(1) Gas-liquid separation of etching waste liquid: a heating device is arranged outside the heating evaporation tank 2, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boil in the heating evaporation tank 2, evaporation and concentration are carried out for 5 hours until a precipitate C can be separated out by naked eyes, and a solid-liquid mixture A1 is obtained and is pumped into the acid-base adjustment tank 1; gas escaped in the heating process is collected and introduced into the combination reaction tank 3;

(2) adjusting the pH value: pouring the A1 solid-liquid mixture and hydrochloric acid into an acid-base adjusting tank 1, mixing, adjusting pH to 4, and filtering by a filter 5 to obtain a solid mixture (containing copper chloride hydroxide).

(3) And (3) gas treatment: under the regulation of the concentration of the compressed gas of the added carbon dioxide, the ratio of the concentration of the ammonia gas to the concentration of the carbon dioxide in the first combination reaction tank 3 is about 5:1 so as to obtain ammonium carbonate through reaction;

(4) mixing the solution: meanwhile, the filtrate A2 is used for flushing the combination reaction tank 3 by utilizing the filtration pressure so as to lead the ammonium carbonate obtained in the step (1) to be taken out from the tank and become A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(5) regeneration of etching solution: and adding the required components to the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in the sub-solution preparation tank 4 to prepare the circularly regenerated etching sub-solution Z. The prepared cyclic regeneration etching sub-liquid is automatically detected by an automatic detection feeding control machine according to the pH parameter in the table 1 and is added to an etching production line for etching working procedures, etching quality test is carried out according to the method for preparing the alkaline etching waste liquid J, and the etching rate and the etching factor K are recorded in the table 1.

Example 4, refer to FIG. 4

(1) Gas-liquid separation of etching waste liquid: heating the alkaline etching waste liquid J with the parameters in the table 1 to 100 ℃ by using a heating evaporation tank 2 provided with a reflux stirring device and a heating device outside, carrying out evaporation concentration for 8 hours until a precipitate C is separated out by naked eyes, obtaining an A1 solid-liquid mixture, and pumping the mixture into an acid-base adjusting tank 1; the gas escaped in the heating process is collected and respectively introduced into the first and second combination reaction tanks 3;

(2) adjusting the pH value: pouring the A1 solid-liquid mixture and the circuit board acidic etching waste liquid S into an acid-base adjusting tank 1, mixing, adjusting pH to 5, and filtering by a filter 5 to obtain a solid mixture (containing basic copper chloride)

(3) And (3) gas treatment: under the regulation of the concentration of the externally added carbon dioxide compressed gas, the ratio of the concentration of ammonia gas to the concentration of carbon dioxide in the first combination reaction tank 3 is about 7.5:1 to obtain ammonium carbonate through reaction, the concentration of carbon dioxide in the second combination reaction tank 3 is higher than that of ammonia gas, and the molar concentration ratio of carbon dioxide to ammonia gas is kept about 10:1 to obtain ammonium bicarbonate through reaction;

(4) mixing the solution: flushing the first and second reaction tanks 3 with the filtrate A2 using the filtration pressure in the filter 5 to take out the ammonium carbonate and ammonium bicarbonate obtained in step (1) from the tanks to obtain an A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(5) regeneration of etching solution: and adding the required components to the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in the sub-solution preparation tank 4 to prepare the circularly regenerated etching sub-solution Z. The prepared cyclic regeneration etching sub-liquid is automatically detected by an automatic detection feeding control machine according to specific gravity parameters in the table 1 and is fed on an etching production line for etching working procedures, etching quality test is carried out according to the method for preparing the alkaline etching waste liquid J, and the etching rate and the etching factor K are recorded in the table 1.

Example 5, refer to FIG. 5

(1) Gas-liquid separation of etching waste liquid: heating the alkaline etching waste liquid J with the parameters in the table 1 to 50 ℃ by using a heating evaporation tank 2 which is provided with a motor-driven stirring device and is externally provided with a heating device, carrying out evaporation concentration for 48 hours, separating out a precipitate C to obtain an A1 solid-liquid mixture, and pumping the solid-liquid mixture into an acid-base adjusting tank 1; collecting the gas escaped in the heating process and respectively introducing the gas into a first and a second combined reaction tanks 3 which are also provided with a jet device 6 for tail gas guide and collection treatment;

(2) adjusting the pH value: mixing the A1 solid-liquid mixture and the circuit board acidic etching waste liquid S in an acid-base adjusting tank 1 to adjust the pH value to 5, and filtering by a filter 5 to obtain a solid mixture (containing basic copper chloride);

(3) and (3) gas treatment: under the regulation of the concentration of the externally added carbon dioxide compressed gas, the ratio of the concentration of the ammonia gas to the concentration of the carbon dioxide gas in the first combination reaction tank 3 is about 5.2:1 to obtain ammonium carbonate through reaction, the concentration of the carbon dioxide gas in the second combination reaction tank 3 is higher than the concentration of the ammonia gas, and the molar concentration ratio of the carbon dioxide to the ammonia gas is kept about 1.01:1 to obtain ammonium bicarbonate through reaction; the tail gas of the chemical combination reaction tank 3 is mixed with water and absorbed through a connected jet device 6; the collecting cylinder of the jet device 6 is provided with a pH meter for carrying out pH detection on the solution in the collecting cylinder, and the amount of carbon dioxide entering the second combination reaction tank 3 is automatically controlled through the measured numerical value;

(4) mixing of solutions): the filter 5 flushes the first and second combination reaction tanks 3 with the filtrate A2 using a filtration pressure to take out the ammonium carbonate and ammonium bicarbonate obtained in the step (1) from the tanks to become an A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(5) regeneration of etching solution: and adding and supplementing other required components into the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in the sub-solution preparation tank 4 to prepare the circularly regenerated etching sub-solution Z. The prepared cyclic regeneration etching sub-liquid is automatically detected by an automatic detection feeding control machine according to specific gravity parameters in the table 1 and is fed on an etching production line for etching working procedures, etching quality test is carried out according to the method for preparing the alkaline etching waste liquid J, and the etching rate and the etching factor K are recorded in the table 1.

Example 6, refer to FIG. 6

(1) Gas-liquid separation of etching waste liquid:

a heating device is arranged outside the heating evaporation tank 2, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boiling, evaporation and concentration are carried out for 8 hours until precipitates C can be separated out by naked eyes, and A1 solid-liquid mixture is obtained and pumped into the acid-base adjustment tank 1; collecting and introducing gas escaped in the heating process into the combination reaction tank 3, and enabling the ratio of the ammonia gas quantity concentration to the carbon dioxide quantity concentration in the combination reaction tank 3 to be about 5.2:1 so as to obtain ammonium carbonate through reaction;

(2) adjusting the pH value: mixing the A1 solid-liquid mixture with hydrochloric acid in an acid-base adjusting tank 1 to adjust the pH value to 4, filtering by a filter 5 to obtain a solid mixture (containing basic copper chloride), and flushing a chemical combination reaction tank 3 by using a filtrate A2 by using filtering pressure to take the ammonium carbonate obtained in the step (1) out of the tank to obtain an A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(3) and (3) gas treatment: the ratio of the ammonia gas concentration to the carbon dioxide gas concentration in the chemical combination reaction tank 3 is about 5.2:1 to obtain ammonium carbonate through reaction;

(4) mixing the solution: the filter 5 flushes the chemical combination reaction tank 3 with the filtrate A2 by using the filtration pressure to take out the ammonium carbonate obtained in the step (1) from the tank to obtain an A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(5) regeneration of etching solution: adding and supplementing required components into the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in a sub-solution preparation tank 4 to prepare a circularly regenerated etching sub-solution Z, automatically detecting and adding the circularly regenerated etching sub-solution Z according to specific gravity parameters in the table 1 by an automatic detection and feeding control machine, automatically detecting and adding 25% ammonia water solution X according to the pH value to be used in an etching process on an etching production line, carrying out an etching quality test according to the method for preparing the alkaline etching waste liquid J, and recording the etching rate and the etching factor K in the table 1.

Example 7

The contents of the components of example 7 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated. Wherein the ratio of the concentration of ammonia gas to the concentration of carbon dioxide gas in the first combination reaction tank 3 is about 9:1 to obtain ammonium carbonate by the reaction.

The etching quality test was carried out according to the method described for the preparation of alkaline etching waste liquid J, and the etching rate and the etching factor K are shown in Table 1.

Example 8

The contents of the components of example 8 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 3 is repeated. Wherein, the alkaline waste etching solution J with the parameters in the table 1 is heated to boiling and evaporated and concentrated for 6 hours.

Example 9

The contents of the components of example 9 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 3 is repeated. Wherein, the alkaline waste etching solution J with the parameters in the table 1 is heated to boiling and evaporated and concentrated for 12 hours.

Example 10

The contents of the components of example 10 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated. Wherein, the alkaline waste etching solution J with the parameters in the table 1 is heated to boiling and evaporated and concentrated for 15 hours.

Example 11

The contents of the components of example 11 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 1 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in the table 1 is heated to 70 ℃ and is evaporated and concentrated for 3 hours, so that the carbon dioxide concentration of the chemical combination reaction tank 3 is higher than the ammonia gas concentration for chemical reaction, and the molar concentration ratio of the carbon dioxide to the ammonia gas is kept to be about 500: 1.

Example 12

The contents of the components of example 12 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 3 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boiling and is evaporated and concentrated for 15 hours, the heating evaporation tank 2 and the acid-base adjusting tank 1 are not connected by a pipeline, a solid-liquid mixture A1 is transferred manually, and a heating device is arranged near the liquid inlet of the chemical combination reaction tank 3.

Example 13

The contents of the components of example 13 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 3 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boiling and is evaporated and concentrated for 15 hours, and heating devices are arranged near a carbon dioxide inlet, a waste liquid gas inlet and a liquid inlet of the chemical combination reaction tank 3.

Example 14

The contents of the components of example 14 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated. Wherein, the alkaline waste etching solution J with the parameters in the table 1 is heated to boiling and evaporated and concentrated for 15 hours.

Example 15

The contents of the components of example 15 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in Table 1 is heated to boiling and evaporated and concentrated for 50 hours, and the ratio of the ammonia concentration to the carbon dioxide concentration in the first combination reaction tank 3 is about 8.3:1, so as to obtain ammonium carbonate through reaction.

Example 16

The contents of the components of example 16 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 1 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in the table 1 is heated to boiling and is evaporated and concentrated for 4.5 hours, an air outlet is arranged on the chemical combination reaction tank 3 besides a carbon dioxide inlet and a waste liquid gas inlet, so that the carbon dioxide quantity concentration of the chemical combination reaction tank 3 is higher than the ammonia gas quantity concentration, the molar weight concentration ratio of the carbon dioxide to the ammonia gas is kept about 100:1, ammonium bicarbonate is obtained by reaction, no pipeline is arranged between the chemical combination reaction tank 3 and the sub-liquid blending tank 4, and the ammonium bicarbonate generated in the chemical combination reaction tank 3 is manually transferred.

Examples 17 and 18

The contents of the components of examples 17 and 18 and the parameters for the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated. Wherein, the alkaline etching waste liquid J with the parameters in Table 1 is heated to boiling and evaporated and concentrated for 50 hours, and the ratio of the ammonia concentration to the carbon dioxide concentration in the first combination reaction tank 3 is about 8.3:1, so as to obtain ammonium carbonate through reaction.

Example 19

The contents of the components of example 19 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 5 is repeated.

Example 20

The contents of the components of example 20 and the parameters of the automatic test feed control machine are shown in table 1 below, and the procedure of example 3 is repeated. Wherein, the alkaline waste etching solution J with the parameters in the table 1 is heated to boiling and evaporated and concentrated for 6 hours.

Example 21, see FIG. 7

(1) Gas-liquid separation of etching waste liquid: heating devices are arranged outside the first heating evaporation tank 2-1 and the second heating evaporation tank 2-2, alkaline etching waste liquid J with parameters in the table 1 is heated in the first heating evaporation tank 2-1 to be boiled in, the second heating evaporation tank 2-2 is heated to 30 ℃, evaporation concentration is carried out for 8 hours until precipitates C are separated out by naked eyes, and A1 solid-liquid mixture is obtained and is respectively pumped and discharged into the first acid-base adjusting tank 1 and the second acid-base adjusting tank 1; collecting and introducing gas emitted in the heating process into a combination reaction, and enabling the ratio of the ammonia gas quantity concentration to the carbon dioxide quantity concentration in the combination reaction tank 3 to be about 5.2:1 so as to obtain ammonium carbonate through the reaction;

(2) adjusting the pH value: adding hydrochloric acid into an acid-base adjusting tank 1, mixing with a solid-liquid mixture A1 in the tank, adjusting the pH value to 4, and filtering by a filter 5 to obtain a precipitate C and a mixed solution A2, wherein the main component of the precipitate C is solid basic copper chloride; meanwhile, the filtrate A2 is used for flushing the combination reaction tank 3 by utilizing the filtration pressure so as to lead the ammonium carbonate obtained in the step (1) to be taken out from the tank and become A3 mixed solution; then draining the wastewater into the seed solution adjusting tank 4;

(3) regeneration of the solution: adding and supplementing required components into the A3 mixed solution according to the component proportion of the circularly regenerated sub-solution required by the etching process in the table 1 in a sub-solution preparation tank 4 to prepare a circularly regenerated etching sub-solution Z, automatically detecting and adding the circularly regenerated etching sub-solution Z according to specific gravity parameters in the table 1 by an automatic detection and feeding control machine, automatically detecting and adding 25% ammonia water solution X according to the pH value to be used in an etching process on an etching production line, carrying out an etching quality test according to the method for preparing the alkaline etching waste liquid J, and recording the etching rate and the etching factor K in the table 1.

TABLE 1

According to the data in table 1, the etching rate of the recyclable etching solution obtained by the invention meets the efficiency of the current industrial scale production, and the defect of quality reduction does not exist.

The above-described embodiments of the present invention are not intended to limit the scope of the present invention, and the embodiments of the present invention are not limited thereto, and various other modifications, substitutions and alterations can be made to the above-described structure of the present invention without departing from the basic technical concept of the present invention as described above, according to the common technical knowledge and conventional means in the field of the present invention.

Claims

An ammonia distillation recovery and circulation process for alkaline etching waste liquid of a circuit board is characterized by comprising the following steps:

(1) gas-liquid separation of etching waste liquid: heating the alkaline etching waste liquid with the copper ion concentration of 30-180g/L, pH value of 7-9, and collecting gas generated in the heating process to obtain waste liquid gas; when the etching waste liquid is heated until a precipitate is separated out, a solid-liquid mixture A1 is obtained;

(2) adjusting the pH value: mixing the solid-liquid mixture A1 obtained in the step (1) with hydrochloric acid and/or acidic etching waste liquid, adjusting the pH to 3-6, further increasing the precipitate in the solid-liquid mixture A1, and separating the precipitate in the obtained solid-liquid mixture A1; respectively obtaining solid precipitates and a mixed solution A2 after solid-liquid separation;

(3) and (3) gas treatment: mixing the waste liquid gas collected in the step (1) with carbon dioxide to generate ammonium carbonate and/or ammonium bicarbonate;

(4) mixing the solution, namely adding ammonium carbonate and/or ammonium bicarbonate into the mixed solution A2 obtained in the step ⑵ to obtain a mixed solution A3;

(5) and (4) regeneration of the etching sub-solution, namely supplementing other required components of the etching process in the mixed solution A3 obtained in the step ⑷ to obtain the recycled etching sub-solution.
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 1, which is characterized in that: in the step (4), the solid-liquid mixture A1 obtained in the step (1) is used, and when the pH value is adjusted in the step (2) and then filtration separation is carried out, the ammonium carbonate and/or ammonium bicarbonate obtained in the step (3) is washed and dissolved by the filtered mixed solution A2, so that the mixed solution A3 is obtained.
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 1, which is characterized in that: in the step (3), the gas collected in the step (1) is divided into two parts, so that the mass concentration of the ammonia gas in the first part is greater than that of the carbon dioxide; the mass concentration of the second portion of ammonia gas is made less than the mass concentration of the carbon dioxide species in order to control the ratio of ammonium carbonate and ammonium bicarbonate produced.
The ammonia distillation recycling process of alkaline waste etching solution for circuit boards according to claim 1 or claim 3, characterized in that: and (3) a jet device is used, and water is used as jet liquid to absorb tail gas of the synthesis reaction of the waste liquid gas and carbon dioxide to generate ammonium carbonate and/or ammonium bicarbonate.
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 4, which is characterized in that: in the step (3), a jet device is used, and water is used as jet liquid to absorb tail gas of a synthesis reaction of the waste liquid gas and carbon dioxide to generate ammonium carbonate and/or ammonium bicarbonate so as to obtain an aqueous solution; and (3) detecting the pH value of the aqueous solution obtained in the jet device by using a pH meter, and controlling the adding amount of the carbon dioxide gas in the step (3).
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 1, which is characterized in that: and (2) stirring the alkaline etching waste liquid by using a stirring device in the heating process of the step (1) so as to promote gas to escape from a stirring position.
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 4, which is characterized in that: and (2) stirring the alkaline etching waste liquid by using a stirring device in the heating process of the step (1) so as to promote gas to escape from a stirring position.
The ammonia distillation recycling process of alkaline waste etching solution for circuit boards of claim 1 or claim 5, which is characterized in that: and (2) during and/or after the heating process in the step (1), injecting air into the alkaline etching waste liquid by using an external pressurized air insertion tube, stirring the mixture in the heating container, and simultaneously promoting the volatilized gas of the mixture to rapidly enter the step (3) for synthesis reaction.
The ammonia distillation recovery and circulation process of the alkaline waste etching solution for circuit boards as claimed in claim 1, which is characterized in that: and (3) other required components of the etching process in the step (5) comprise at least one of ammonium chloride, ammonia water, ammonium bicarbonate, water and etching additives.
A system for recycling ammonia evaporation from alkaline waste etching solution for circuit boards as claimed in any of claims 1 to 9, comprising:

at least one acid-base adjusting tank ⑴ for adjusting the pH value of the residual liquid after the alkaline waste etching solution is evaporated;

at least one heating evaporation tank ⑵, which is composed of a heating device and an air outlet arranged inside and/or outside the heating evaporation tank, and is used for concentrating and heating the alkaline etching waste liquid and separating the waste liquid gas;

at least one combination reaction tank ⑶, which is provided with a carbon dioxide inlet and a waste gas inlet, wherein the carbon dioxide inlet is connected with a carbon dioxide source, and the waste gas inlet is connected with the gas outlet of the heating evaporation tank and is used for producing ammonium carbonate and/or ammonium bicarbonate;

the device comprises at least one filter, a liquid-solid separation device and a liquid-solid separation device, wherein the filter is used for separating solid and liquid in a solid-liquid mixture, an inlet of the filter is connected with an acid-base adjusting tank, and a liquid outlet of the filter is connected with a sub-liquid adjusting tank or a chemical combination reaction tank;

and the seed solution preparing tank is used for preparing the circularly regenerated etching seed solution.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10, characterized in that: and a stirring device is arranged in the heating evaporation tank.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10 or 11, characterized in that: the heating evaporation tank is provided with an external pressurized air insertion pipe; the external pressurized air insertion pipe is composed of a pipeline and a pump, wherein the pipeline is communicated with the inside of the heating evaporation groove and the outside.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10, characterized in that: a pump is arranged on a pipeline connecting the heating evaporation tank and the chemical combination reaction tank and/or at the air outlet of the chemical combination reaction tank.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10, characterized in that: the combination reaction tank is provided with an additional air outlet and/or an additional liquid inlet and/or a discharge port.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10, characterized in that: and a heating device is arranged near the carbon dioxide inlet and/or the waste liquid gas inlet and/or the liquid inlet of the combination reaction tank.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 10, characterized in that: the chemical combination reaction tank is connected with the jet device;

the jet flow vacuum device is provided with a gas-liquid mixing cavity and a collecting cylinder, and water is stored in the collecting cylinder and used for dissolving tail gas of the chemical combination reaction tank;

the gas-liquid mixing cavity is respectively provided with a jet air suction port, a jet liquid inlet and a jet liquid outlet, and the jet liquid outlet extends into the collecting cylinder through a liquid outlet pipe; the jet liquid inlet is connected with the collecting cylinder through an absorption liquid circulating pipe and a liquid inlet pump arranged on the pipeline.
The recycling system of ammonia distillation of alkaline waste etching solution for circuit boards of claim 14, wherein: and a pH meter is arranged in a collecting cylinder of the jet device and is used for detecting the pH value of liquid in the collecting cylinder.