KR100790370B1 - Recycling method and apparatus of waste etching solution - Google Patents

Abstract

An apparatus and a method for recycling a waste etchant are provided to recycle the waste etchant using a system comprising a microfilter, a nanofilter and a mixing equipment as a system for removing insoluble particles and a plurality of metal ion components separated by a chemical reaction between an etchant and a matrix and recovering and recycling components of the initial etchant such as deionized water, nitric acid and hydrochloric acid. An apparatus for recycling a waste etchant comprises: a waste etchant storage tank(1) which is connected to a waste etchant supply pipe(10), and stores a waste etchant; a microfilter(2) for primarily treating the waste etchant supplied from the waste etchant storage tank by a pump; a nanofilter(3) which secondly treats the primarily treated waste etchant supplied from the microfilter by a pump, and which has a waste etchant recovering and treating pipe(20) formed on one side of the bottom thereof; a mixing tank(4) of which one side is connected to the nanofilter to store the etchant treated in the nanofilter, and of which the other side is connected to a nitric acid supply pipe(30) and a hydrochloric acid supply pipe(40); and a recycled etchant storage tank(5) of which one side is connected to the mixing tank to store a recycled etchant, and of which the other side is connected to an etchant recovery pipe(50).

Description

Recycling apparatus for waste etching liquid and its recycling method {RECYCLING METHOD AND APPARATUS OF WASTE ETCHING SOLUTION}

 1 is a regeneration process chart of the waste etching solution of the present invention

<Description of the Drawings>

Waste etching liquid storage tank (1), micro filter (2), nano filter (3), mixing tank (4), recycled etching liquid storage tank (5), waste etching liquid supply pipe (10), waste recovery treatment pipe (20), nitric acid supply pipe (30), hydrochloric acid supply pipe (40), etching liquid recovery pipe (50),

The present invention relates to an apparatus for recycling waste etching liquid which is discarded after being used in an etching process using a microfilter and a nanofilter, and a method for regenerating the same.

The etching (etching) process in semiconductor, PCB, and LCD manufacturing processes is a process of selectively removing unnecessary parts by using chemicals or reactive gases to form circuit patterns, and has been widely used as an industrial metal etching solution. . However, since the etchant composed of the above components is very strong acid, the etchant remaining after the etching is very harmful to the environment and must be neutralized to be treated. The treatment is very difficult, and the processing cost is high, and there have been many studies to recycle it.

For example, Korean Laid-Open Patent Publication No. 10-2004-25583 discloses a method of regenerating an etching solution composed of an aqueous phosphate solution used to etch a silicon nitride film in an etching bath, wherein the silicon compound generated by the etching is included. The etching solution to be extracted from the etching bath, water was added to the extracted etching solution to lower the phosphoric acid concentration of the etching solution to 80 to 50% by weight, and the silicon compound precipitated in the etching solution by the decrease in the phosphoric acid concentration was removed from the etching solution. The etching method, the etching method and the etching apparatus are described

Publication Nos. 2003-53247 and 2003-532228 disclose the steps of recovering hydrochloric acid by vacuum evaporation of a mixed solution of waste sulfuric acid etchant comprising aluminum and waste hydrochloric acid etchant comprising aluminum; After the vacuum evaporation, adding aluminum to the waste sulfuric acid etching solution containing aluminum, the waste sulfuric acid etching solution and waste hydrochloric acid etching solution comprising the step of diffusing dialysis of the aluminum acid-added waste acid etching solution to the sulfuric acid and aluminum sulfate water treatment flocculant How to play it,

Publication No. 10-2006-72559 discloses a first step of filtering indium tin oxide etching waste liquid through a microfilter to remove insoluble impurities; After the first step, the indium tin comprises a second step of recovering the acid by vacuum evaporation of the filtrate of the microfilter, and a third step of separating and recovering indium and tin by electrolytically collecting the residual solution after the second step. A method for recovering acid and recovering indium and tin from an oxide etching waste liquid is described.

Korean Patent Publication No. 10-2006-49695 discloses an acid etching solution regeneration method and an acid etching solution comprising a filtration process in which an oxalic acid-containing etching solution used for etching indium tin oxide is filtered by a nanofilter membrane and separated into a permeate solution and a non-permeate solution. A playback device is described,

Publication No. 10-2006-11699 discloses a step of distilling an etching waste liquid containing phosphoric acid to distill leaving only phosphoric acid, diluting with diluent material, nanofilters, and optionally a chelating resin and a cation exchange resin. There is disclosed a method for regenerating aluminum etching waste liquid and refining phosphoric acid comprising the steps of preparing high purity phosphoric acid and regenerating with etching liquid.

In the conventional technology as described above, the etching solution used once in the current process is transferred to the wastewater treatment plant, and thus, there is a problem in that the load of the wastewater treatment plant is increased and the cost for producing the etching solution is high.

In order to solve the above problems, the present invention removes insoluble particle components and metal ions such as iron, copper, zinc, arsenic, and lead (hereinafter referred to as "metal ions") that are separated from the base material by chemical reaction between the etching solution and the base material. The present invention is to provide a regeneration apparatus for regenerating etching liquid using a device composed of a micro filter, a nano filter, and a mixing device as a system for recovering the initial etching liquid components, such as pure water, nitric acid, hydrochloric acid, and the like. It is a technical task.

In order to achieve the above technical problem, the present invention is to remove the insoluble particle component by using the first micro-filter the etching liquid discarded after use, and then transferred to the nano-filter with a high-pressure pump to remove metal ions, etc. pure water, nitric acid, hydrochloric acid The present invention relates to a reproducing apparatus for recovering and using the same and to reusing the same.

The micro filter used in the present invention uses a micro filter commonly used in the field of filtration.

Nano-filters currently available can be used, and the types thereof include NF90-2540, NF90-4040, NF90-400, NF200-400, NF270-400, NF270-2540, NF270-4040, and NF-400 manufactured by Filmtec; CK2540FF, CK4040FF, CK8040F, CK8040N, Duraslick NF2540, Duraslick NF4040, Duraslick NF8040, HL2514T, HL2514TF, HL2540FF, HL2540TF, HL4018F, HL3FFT, HL4014TF, HL4014TF , HL8040N, DK2540F, DK4040F, DK8040F, DK2540C, DK4040C, DK8040C, DL2540F, DL4040F, DL8040F, DL2540C, DL4040C, DL8040C, Duracid NF2540C, Duracid NF4040C, Duracid NF8040C etc.

Nanofilters have a pore size of about 0.001 to 0.01 microns and can be used to filter out materials with atomic weights above about 200, but are not yet common. Recently, with the development of nanotechnology, the use of nanofilters in the separation / concentration process and water softening process in the fine chemical field is increasing, and a large amount of salts used in dye and pigment manufacturing processes are effectively separated from the purification process. Nanofilter membranes have also been used to make them. In addition, nanofilters are actively used for the purification of small pharmaceuticals, dyes and the like.

Nano-filter of the present invention as a material that can withstand at 60 ℃, it is possible to use a high acid resistance material, such as polyether sulfone (PES), polysulfone,

The waste etching solution supply pressure supplied from the micro filter by the pump formed on one side may be supplied at a high pressure (about 10 to 30 kgf / cm 2).

The composition of the waste etching solution of the present invention is pure water: 90% or more, nitric acid: 2-8%, hydrochloric acid: 0.1-1%, insoluble particle component and 10-1000 ppm of metal ions,

It was developed to recover and reuse nitric acid: 1.8 ~ 7.6%, hydrochloric acid: 0.09 ~ 0.9% in the final recovered waste etching solution composition.

Hereinafter, the present invention will be described in detail with reference to the following Examples.

Example

First process (micro filtering process)

In the waste etching solution storage tank (1) containing 90 kg of pure water , 8 kg of nitric acid, 1 kg of hydrochloric acid, insoluble particles and metal ions, and supplied to the micro filter (2) by a pump, the insoluble particles are filtered out. The ingredients pass through,

2nd process (recovery process)

The waste etching solution first treated in the micro filter 2 is supplied to the nanofilter 3 by a high pressure (about 10 to 30 kgf / cm 2) by a pump to remove the metal ions and the like. ) And then, the lower one side discharges the waste liquid containing a high concentration of metal ions through the waste recovery pipe 20,

3rd process (regeneration process)

When the etching liquid recovered from the nano-filter 3 is transferred to the mixing tank 4, nitric acid and hydrochloric acid are supplied through the nitric acid supply pipe 30 and the hydrochloric acid supply pipe 40 installed on one side using a sensor installed therein, After the transfer to the regeneration etching solution storage tank (5) by the pump installed in the lower, the waste etching solution was regenerated to reuse through the etching liquid recovery pipe (50) connected to the bottom of the regeneration etching solution storage tank (5).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

 1 is a process for regenerating waste etching liquid of the present invention, waste etching liquid storage tank (1), micro filter (2), nano filter (3), mixing tank (4), regeneration etching liquid storage tank (5), waste etching liquid supply pipe (10), the waste recovery tube 20, the nitric acid supply tube 30, the hydrochloric acid supply tube 40, the etching liquid recovery tube 50 is shown.

Looking at the structure, as shown in Figure 1, the waste etching liquid storage tank (1) for connecting and storing the used etching liquid by the waste etching liquid supply pipe 10, and is supplied by the pump from the waste etching liquid storage tank (1) The microfilter 2 to be treated, and the waste etching solution treated by the microfilter 2 is supplied by a pump for secondary treatment, and a nanofilter 3 having a waste recovery tube 20 at one lower side thereof. Is connected to store the liquid treated in the nano-filter (3), the other side is mixed with the mixed tank (4) connected to the nitric acid supply pipe 30 and the hydrochloric acid supply pipe 40 , the regenerated connected to the mixing tank (4) The etchant is stored, and the other side is a regeneration apparatus of the waste etchant consisting of a regeneration etchant storage tank (5) equipped with an etchant recovery tube (50).

As described above, the present invention has an eco-friendly advantage of minimizing waste water generation as well as the economic effect of recycling the recycled nitric acid and hydrochloric acid with high purity by treating the waste etching solution continuously within a short time using a micro filter and a nano filter. will be.

Claims (2)

In the regeneration method of the waste etching liquid, First process (micro filtering process) In the waste etching liquid storage tank 1 in which the waste etching liquid is stored, the insoluble particle component in the waste etching liquid supplied to the micro filter 2 by the pump is first treated and removed. 2nd process (recovery process) When the waste etching solution treated by the micro filter 2 is supplied to the nano-filter 3 with a waste etching solution supply pressure of 10 to 30 kgf / cm 2 by a pump, the metal ions are removed and then the mixing tank 4 After transferring to, the lower one side to discharge the treated fine particles through the waste recovery tube 20, 3rd process (regeneration process) When the etching liquid treated by the nanofilter 3 is transferred to the mixed tank 4 stored therein, nitric acid and hydrochloric acid are supplied through the nitric acid supply pipe 30 and the hydrochloric acid supply pipe 40 installed on one side using a sensor installed therein. After the transfer to the regeneration etching liquid storage tank (5) by the pump installed in the lower, and reused through the etching solution recovery pipe 50 installed in the lower portion of the regeneration etching liquid storage tank (5) . In the recycling apparatus of the waste etching liquid, The waste etching liquid storage tank 1 for storing and storing the used etching liquid by the waste etching liquid supply pipe 10, the micro filter 2 which is supplied and processed by the pump from the waste etching liquid storage tank 1, and the micro The waste etching solution treated by the filter (2) is supplied by a pump for secondary treatment, and at the lower side thereof, a nano filter (3) equipped with a waste recovery tube (20), and a liquid treated by the nano filter (3). It is connected to the storage side, the other side of the nitric acid supply pipe 30 and the hydrochloric acid supply pipe 40 is connected to the mixed tank 4, and the regenerated etching solution connected to the mixing tank 4, the other side of the etching solution recovery pipe A regeneration etchant storage tank characterized in that it comprises a regeneration etchant storage tank (5) provided with (50).

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