KR101392179B1 - Recovery method of platinum group metal and apparatus for recovering platinum group metal - Google Patents

Abstract

The present invention relates to a method and an apparatus for recovering platinum group metals, and the method includes the steps of: dissolving platinum group metals through leaching in aqua regia or electroleaching of scraps containing platinum and rhodium or waste fire bricks containing platinum and rhodium; allowing the leaching liquid where the platinum group metals are leached and dissolved to be passed through an ion exchange column in which a negative ion exchange resin is filled so that platinum adheres to the negative ion exchange resin; burning the negative ion exchange resin to which platinum adheres; leaching and dissolving platinum from the burned result material; heating and evaporating the dissolved result material to conduct denitrification; and reducing the result material after the denitrification to obtain sediments therefrom and conducting a calcination process of the sediments to recovery platinum, conducting substitution reaction of the result material after the denitrification by using oxidation/reduction potential difference to recovery platinum, or conducting electrochemical recovery process of the result material after the denitrification to recovery platinum. According to the present invention, the method and apparatus can reduce the amounts of acid and energy consumption used in the continuous leaching process of the platinum group metals contained in the scraps containing platinum and rhodium or in the waste fire bricks containing platinum and rhodium, decrease the amounts of waste water and waste acid containing lead, and diminish the amount of waste gas containing NOx, thus effectively separating and refining a large amount of platinum group metals.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of recovering a platinum group metal and a method of recovering a platinum group metal used therefor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a platinum group metal and an apparatus for recovering a platinum group metal used therefor and more particularly to a method for recovering a platinum group metal contained in scrap containing platinum and rhodium, , It is possible to reduce the amount of acid and energy consumed in the leaching process, reduce the generation of wastewater containing lead and waste acid, reduce the generation of waste gas containing NOx, and effectively remove and refine a large amount of platinum group metal To a method of recovering metals and a recovering apparatus for recovering platinum group metals used therefor.

Platinum Group Metal (PGM) refers to a generic term of six elements including ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt). In addition to excellent physical properties with high melting point and high specific gravity, platinum group metals (PGM) are not eroded by acids or alkalis and chemically inert. Therefore, they are used in automobile exhaust gas purification catalysts, petroleum and chemical industries, And the like. Recently, the demand has been rapidly increasing.

However, since these platinum group metals have a limited amount of reserves, studies on processes and devices for recovering precious metals from waste materials such as automobile catalyst parts, oil stabilizer parts, and electronic products have actively been conducted, and the development of the electronic industry , The demand for technology to extract platinum group metals efficiently and economically from the waste materials generated from the process as well as the main materials due to the increase of the production due to the development of the display industry and the increase of the scrap due to the increase of demand Is emerging.

Techniques for recovering platinum group metals from waste materials can largely be divided into a high temperature dry recovery method and a wet recovery method.

The high temperature dry recovery method is mainly used in developed countries and includes melting, sintering, melting in a furnace, plasma, electric arc furnace, or gas phase reaction at a high temperature. Although this method is suitable for large capacity treatment, it has a problem of large volume slag, loss of precious metal and air pollution due to operation of large scale melting furnace.

The wet recovery method is suitable when the throughput is low, there is no occurrence of slag, and the installation cost is small, but it has a problem of generation of waste water.

Among the platinum group metals, platinum and rhodium have similar chemical properties and, when present in the form of an alloy, have considerable difficulties in separating and purifying the two materials. Conventional studies on the separation and purification of platinum group elements have been technologically advanced through a method of solvent leaching (solvent extraction) in which one kind of platinum group element is organometallized and separated by using a solvent.

However, in the case of the solvent extraction method, not only a separate solvent but also a repetitive solvent extraction process is required to obtain a high purity platinum group metal.

SUMMARY OF THE INVENTION The object of the present invention is to reduce the amount of acid and energy consumed during the leaching process through continuous processing of scrap containing platinum and rhodium or platinum group metals contained in a pyrolytic brick containing platinum and rhodium, The present invention provides a method for recovering a platinum group metal capable of reducing the generation of wastewater and waste acid and capable of efficiently separating and purifying a large amount of platinum group metal by reducing the generation of waste gas containing NO x and a recovering apparatus for a platinum group metal used therein .

The present invention relates to a method for producing a leached refractory brick, comprising the steps of: (a) leaching or electrolytically leaching a scrap containing platinum and rhodium or a pyrolytic brick containing platinum and rhodium to dissolve the platinum group metal; (b) (C) incinerating the anion exchange resin adsorbed on the platinum; and (d) adsorbing platinum on the anion exchange resin in the incinerated product. (E) dissolving and dissolving the resulting product in a denitrifying process; and (f) subjecting the resultant obtained through the denitrification process to a reduction reaction to obtain a precipitate, calcining the precipitate to recover platinum , The result obtained through the denitrification process is recovered as a platinum metal through the substitution reaction using the difference of redox potentials, or the product obtained through the denitrification process is electrolytically recovered, And recovering the platinum group metal.

The method for recovering the platinum group metal may further include a step of removing a cation exchange column packed with a strongly acidic cation exchange resin after the step (a) and before the step (b), in which the platinum group metal is leached and dissolved to recover more purified platinum And then removing the cationic impurities.

The method for recovering the platinum group metal may include a step of removing the cation impurities by passing the leaching solution passed through the ion exchange column through the cation removal column packed with the strongly acidic cation exchange resin after the step (b) and before the step (c) And recovering rhodium ions from the leachate which has passed through the cation removal column.

A plurality of the ion exchange columns are connected, and the leach solution is continuously passed through a plurality of ion exchange columns so that the platinum is adsorbed on the anion exchange resin to increase the recovery rate of platinum.

Hydrochloric acid (HCl) is used as the leaching solution necessary for the electrolytic leaching, and the hydrochloric acid (HCl) having a concentration of 4 to 12 M is used. During the electrolytic leaching reaction, In order to remove the hydrogen gas and the chlorine gas which cause the deterioration of the leaching efficiency, the leaching solution is stirred using an agitator to circulate the leaching solution in the electrolytic sedimentation tank, leaching the platinum group metal while removing the gas on the electrode surface, The electrolytic leaching of the leachate in the electrolytic sedimentation tank and the leachate storage tank is carried out in order to prevent the hydrogen ion and chlorine ion concentration in the leachate caused by the generation of hydrogen gas and chlorine gas, The leachate reservoir is replenished with hydrochloric acid to continuously leach platinum group metal can do.

The pH of the leaching solution for electrolytic leaching is kept equal to or less than 1.5, and a pH controller is attached to the first leaching solution reservoir to maintain the pH of the leaching solution so that hydrochloric acid is supplied quantitatively from the hydrochloride storage tank to the first leaching solution reservoir The leachate is circulated while the leachate reservoir is replenished with hydrochloric acid to leach platinum group metals.

In step (f), ammonium chloride (NH ₄ Cl) or hydrazin (NH ₂ NH ₂ ) is used as a reducing agent for the reduction reaction, and zinc Zn) or copper (Cu) can be used.

The present invention also provides a leaching apparatus for leaching a platinum group metal, a first leaching solution reservoir for supplying the leaching solution into the leaching tank of the leaching apparatus, a second leaching solution reservoir for storing the leaching solution in which the platinum group metal is leached and dissolved, An ion exchange column filled with a strong basic anion exchange resin supplied from the second leachate storage tank for adsorbing platinum and a leached solution containing leached platinum group metal, A cation exchange column packed with a strongly acidic cation exchange resin to be adsorbed and removed, and a purified liquid storage tank for storing the leachate passed through the cation removal column.

The apparatus for recovering a platinum group metal may further include a hydrochloric acid storage tank for quantitatively supplying hydrochloric acid to the first leachate reservoir for maintaining the pH of the leachate, wherein the leaching apparatus is an electrolytic leaching apparatus, An electrolytic leaching tank storing the leachate and having an acid resistance characteristic, an electrode made of a platinum group metal to be leached, an ac power supply for supplying ac power, a connection for connecting the electrode and the ac power supply, And an agitator for agitating the inside of the leachate. In order to prevent reduction of the hydrogen and chlorine ion concentrations in the leachate due to the generation of hydrogen gas and chlorine gas, which cause deterioration of electrolytic leaching efficiency during the leaching reaction, Wherein the electrolytic leaching solution in the electrolytic sedimentation tank and the leaching solution in the first leachate reservoir Hydrochloric acid (HCl) is used as the leaching solution, the hydrochloric acid (HCl) having a concentration of 4 to 12M is used while the leachate for electrolytic leaching The pH is preferably kept equal to or less than 1.5.

A plurality of the ion exchange columns are connected to each other. A check valve is provided at an input end of each ion exchange column to selectively block the inflow of the leach solution. In order to selectively block the leakage of the leach solution, Wherein the leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column, A check valve for selectively supplying the leaching solution to the storage tank is provided at an output end of the column for removing cation and a check valve for supplying the leaching solution having passed through the column for removing cation to the leaching solution reservoir is connected to an output end And the leachate having passed through the column for removing a cation is introduced into the second leachate reservoir A check valve may be provided at an output end of the cation removal column.

The present invention also provides a leaching apparatus for leaching a platinum group metal, a first leaching solution reservoir for supplying the leaching solution into the leaching tank of the leaching apparatus, a second leaching solution reservoir for storing the leaching solution in which the platinum group metal is leached and dissolved, A cation removal column filled with a strongly acidic cation exchange resin for receiving and leaching a leach solution containing leached platinum group metal from the second leachate reservoir and adsorbing and removing cationic impurities; An ion exchange column filled with a strongly basic anion exchange resin for adsorbing platinum, and a reflux liquid reservoir for storing the leached solution passed through the ion exchange column.

The apparatus for recovering a platinum group metal may further include a hydrochloric acid storage tank for quantitatively supplying hydrochloric acid to the first leachate reservoir for maintaining the pH of the leachate, wherein the leaching apparatus is an electrolytic leaching apparatus, An electrolytic leaching tank storing the leachate and having an acid resistance characteristic, an electrode made of a platinum group metal to be leached, an ac power supply for supplying ac power, a connection for connecting the electrode and the ac power supply, And an agitator for agitating the inside of the leachate. In order to prevent reduction of the hydrogen and chlorine ion concentrations in the leachate due to the generation of hydrogen gas and chlorine gas, which cause deterioration of electrolytic leaching efficiency during the leaching reaction, Wherein the electrolytic leaching solution in the electrolytic sedimentation tank and the leaching solution in the first leachate reservoir Hydrochloric acid (HCl) is used as the leaching solution, the hydrochloric acid (HCl) having a concentration of 4 to 12M is used while the leachate for electrolytic leaching The pH is preferably kept equal to or less than 1.5.

A plurality of the ion exchange columns are connected to each other. A check valve is provided at an input end of each ion exchange column to selectively block the inflow of the leach solution. In order to selectively block the leakage of the leach solution, The leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column, and the ion exchange column at the final stage among the plurality of ion exchange columns A check valve for selectively supplying the leached solution passed through the ion exchange column to the purification liquid storage tank is provided at the output end of the ion exchange column at the final stage and the leach solution having passed through the ion exchange column at the final stage among the plurality of ion exchange columns, A check valve for supplying the ion exchange column to the storage tank is provided at the output end of the ion exchange column at the final stage, A check valve for supplying the leachate having passed through the last stage ion exchange column out of the plurality of ion exchange columns to the second leachate reservoir is provided at the output end of the last stage ion exchange column, A check valve for supplying the leachate passed through the exchange column to the first stage ion exchange column among the plurality of ion exchange columns may be provided at the output end of the last stage ion exchange column.

The apparatus for recovering a platinum group metal may further include an electrolytic collection tank for receiving the solution stored in the purified solution storage tank and recovering rhodium ions to rhodium metal, a pump for transferring the solution stored in the purified solution storage tank to the electrolytic collection tank, An electrolytic harvesting liquid storage tank for receiving the electrolytic harvesting liquid in the electrolytic sampling tank and a pump for transferring the electrolytic harvesting liquid in the electrolytic sampling tank to the electrolytic harvesting liquid storage tank.

According to the present invention, it is possible to provide a platinum group metal alloy containing platinum group metal (Cr) contained in a refractory brick produced by scrap of an alloy of a platinum group metal such as platinum (Pt) - rhodium (Rh) or a melting furnace for producing a high purity glass for a liquid crystal display Can reduce the amount of acid and energy consumed in the leaching process, reduce the generation of wastewater and waste acid containing lead, reduce the generation of waste gas containing NOx, and effectively separate and refine large amounts of platinum group metals. .

In addition, according to the present invention, scrap of waste refractory bricks or platinum-rhodium alloy sheets generated in the re-installation and maintenance of a melting furnace with a remaining lifetime can be recovered through a reduction in process cost and minimization of environmental load, The import substitution effect can be obtained.

1 is a conceptual diagram showing a method for recovering a platinum group metal.
2 is a view schematically showing an electrolytic leaching apparatus according to an example.
3 is a view showing in detail a part of an electrolytic leaching apparatus according to another example.
FIG. 4 is a view showing a state where an electrolytic leaching apparatus, a first leachate storage tank, a hydrochloric acid storage tank, and a constant temperature circulation water tank are connected in a platinum group metal recovery apparatus.
FIG. 5 is a view schematically showing an apparatus for recovering a platinum group metal according to an example.
FIG. 6 is a view schematically showing an apparatus for recovering a platinum group metal according to another embodiment. FIG.
7 is a view schematically showing an apparatus for recovering a platinum group metal according to still another embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not. Wherein like reference numerals refer to like elements throughout.

Hereinafter, the term "royal" means a mixture of hydrochloric acid and nitric acid.

SUMMARY OF THE INVENTION The present invention provides a method for recovering a platinum group metal contained in a platinum-rhodium alloy sheet or a refractory brick of a melting furnace for use in a glass melting furnace for an LCD (Liquid Crystal Display) .

According to a preferred embodiment of the present invention, there is provided a method for recovering a platinum group metal, comprising the steps of: (a) leaching or electrolytically leaching scrap containing platinum and rhodium or a waste refractory brick containing platinum and rhodium to dissolve the platinum group metal; (b) adsorbing platinum on an anion exchange resin through an ion exchange column filled with a strongly basic anion exchange resin, (c) adsorbing the platinum adsorbed anion exchange resin on the anion exchange resin, and (D) leaching platinum out of the incinerated product; (e) performing a denitrification process by heating and evaporating the dissolved product; and (f) subjecting the resultant obtained through the denitrification process to a reduction reaction, The precipitate is calcined to recover platinum, or a product obtained through the denitrification step is recovered as a platinum metal through a substitution reaction using a redox potential difference, And recovering platinum by electrolytic recovery of the resultant product subjected to the denitrification process.

The method for recovering the platinum group metal may further include a step of removing a cation exchange column packed with a strongly acidic cation exchange resin after the step (a) and before the step (b), in which the platinum group metal is leached and dissolved to recover more purified platinum And then removing the cationic impurities.

The method for recovering the platinum group metal may include a step of removing the cation impurities by passing the leaching solution passed through the ion exchange column through the cation removal column packed with the strongly acidic cation exchange resin after the step (b) and before the step (c) And recovering rhodium ions from the leachate which has passed through the cation removal column.

A plurality of the ion exchange columns are connected, and the leach solution is continuously passed through a plurality of ion exchange columns so that the platinum is adsorbed on the anion exchange resin to increase the recovery rate of platinum.

Hydrochloric acid (HCl) is used as the leaching solution necessary for the electrolytic leaching, and the hydrochloric acid (HCl) having a concentration of 4 to 12M is used. The hydrogen lease gas which causes deterioration of the electrolytic leaching efficiency during the electrolytic leaching reaction And chlorine gas is stirred using an agitator to circulate the leaching solution in the electrolytic sedimentation tank and to remove the gas on the surface of the electrode while leaching the platinum group metal and to reduce the efficiency of electrolytic leaching during the electrolytic leaching reaction In order to prevent the decrease of hydrogen ion and chlorine ion concentration in the leaching solution caused by the generation of hydrogen gas and chlorine gas which are the causes of hydrogen leaching and chlorine gas, the leach solution in the electrolytic sedimentation tank and the leachate storage tank are continuously circulated during electrolytic leaching, Can be supplemented with hydrochloric acid to leach platinum group metals.

The pH of the leaching solution for electrolytic leaching is kept equal to or less than 1.5, and a pH controller is attached to the first leaching solution reservoir to maintain the pH of the leaching solution so that hydrochloric acid is supplied quantitatively from the hydrochloride storage tank to the first leaching solution reservoir The leachate is circulated while the leachate reservoir is replenished with hydrochloric acid to leach platinum group metals.

In step (f), ammonium chloride (NH ₄ Cl) or hydrazin (NH ₂ NH ₂ ) is used as a reducing agent for the reduction reaction, and zinc Zn) or copper (Cu) can be used.

The apparatus for recovering a platinum group metal according to a preferred embodiment of the present invention includes a leaching apparatus for leaching a platinum group metal, a first leaching solution reservoir for supplying an leaching solution into a leaching tank of the leaching apparatus, An ion exchange column filled with a strongly basic anion exchange resin for receiving platinum group metal from the second leach solution reservoir and adsorbing platinum, the second leach solution reservoir for storing the leach solution; A cation removal column filled with a strong acidic cation exchange resin for adsorbing and removing cation impurities, and a reflux liquid reservoir for storing the leaching solution passed through the cation removal column.

The apparatus for recovering a platinum group metal may further include a hydrochloric acid storage tank for quantitatively supplying hydrochloric acid to the first leachate reservoir for maintaining the pH of the leachate, wherein the leaching apparatus is an electrolytic leaching apparatus, An electrolytic leaching tank storing the leachate and having an acid resistance characteristic, an electrode made of a platinum group metal to be leached, an ac power supply for supplying ac power, a connection for connecting the electrode and the ac power supply, And an agitator for agitating the inside of the leachate. In order to prevent reduction of the hydrogen and chlorine ion concentrations in the leachate due to the generation of hydrogen gas and chlorine gas, which cause deterioration of electrolytic leaching efficiency during the leaching reaction, Wherein the electrolytic leaching solution in the electrolytic sedimentation tank and the leaching solution in the first leachate reservoir Hydrochloric acid (HCl) is used as the leaching solution, the hydrochloric acid (HCl) having a concentration of 4 to 12M is used while the leachate for electrolytic leaching The pH is preferably kept equal to or less than 1.5.

A plurality of the ion exchange columns are connected to each other. A check valve is provided at an input end of each ion exchange column to selectively block the inflow of the leach solution. In order to selectively block the leakage of the leach solution, Wherein the leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column, A check valve for selectively supplying the leaching solution to the storage tank is provided at an output end of the column for removing cation and a check valve for supplying the leaching solution having passed through the column for removing cation to the leaching solution reservoir is connected to an output end And the leachate having passed through the column for removing a cation is introduced into the second leachate reservoir A check valve may be provided at an output end of the cation removal column.

According to another preferred embodiment of the present invention, there is provided an apparatus for recovering a platinum group metal, comprising: a leaching apparatus for leaching a platinum group metal; a first leaching solution reservoir for supplying an leaching solution into a leaching tank of the leaching apparatus; A column for removing cations filled with a strong acidic cation exchange resin for absorbing and removing cationic impurities from the second leachate reservoir and a second leachate reservoir for storing the leachate; An ion exchange column filled with a strong basic anion exchange resin for receiving the leach through the cation removal column and adsorbing platinum, and a reflux liquid reservoir for storing the leach solution passed through the ion exchange column.

The apparatus for recovering a platinum group metal may further include a hydrochloric acid storage tank for quantitatively supplying hydrochloric acid to the first leachate reservoir for maintaining the pH of the leachate, wherein the leaching apparatus is an electrolytic leaching apparatus, An electrolytic leaching tank storing the leachate and having an acid resistance characteristic, an electrode made of a platinum group metal to be leached, an ac power supply for supplying ac power, a connection for connecting the electrode and the ac power supply, And an agitator for agitating the inside of the leachate. In order to prevent reduction of the hydrogen and chlorine ion concentrations in the leachate due to the generation of hydrogen gas and chlorine gas, which cause deterioration of electrolytic leaching efficiency during the leaching reaction, Wherein the electrolytic leaching solution in the electrolytic sedimentation tank and the leaching solution in the first leachate reservoir Hydrochloric acid (HCl) is used as the leaching solution, the hydrochloric acid (HCl) having a concentration of 4 to 12M is used while the leachate for electrolytic leaching The pH is preferably kept equal to or less than 1.5.

A plurality of the ion exchange columns are connected to each other. A check valve is provided at an input end of each ion exchange column to selectively block the inflow of the leach solution. In order to selectively block the leakage of the leach solution, The leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column, and the ion exchange column at the final stage among the plurality of ion exchange columns A check valve for selectively supplying the leached solution passed through the ion exchange column to the purification liquid storage tank is provided at the output end of the ion exchange column at the final stage and the leach solution having passed through the ion exchange column at the final stage among the plurality of ion exchange columns, A check valve for supplying the ion exchange column to the storage tank is provided at the output end of the ion exchange column at the final stage, A check valve for supplying the leachate having passed through the last stage ion exchange column out of the plurality of ion exchange columns to the second leachate reservoir is provided at the output end of the last stage ion exchange column, A check valve for supplying the leachate passed through the exchange column to the first stage ion exchange column among the plurality of ion exchange columns may be provided at the output end of the last stage ion exchange column.

The apparatus for recovering a platinum group metal may further include an electrolytic collection tank for receiving the solution stored in the purified solution storage tank and recovering rhodium ions to rhodium metal, a pump for transferring the solution stored in the purified solution storage tank to the electrolytic collection tank, An electrolytic harvesting liquid storage tank for receiving the electrolytic harvesting liquid in the electrolytic sampling tank and a pump for transferring the electrolytic harvesting liquid in the electrolytic sampling tank to the electrolytic harvesting liquid storage tank.

Hereinafter, a method of recovering a platinum group metal according to a preferred embodiment of the present invention and an apparatus for recovering a platinum group metal used in the method will be described in detail. 1 is a conceptual diagram showing a method for recovering a platinum group metal.

Referring to FIG. 1, scrap containing platinum and rhodium or leached refractory bricks containing platinum and rhodium is leached or electrolytically leached to dissolve platinum group metals.

Hereinafter, the water-leaching step and the electrolytic leaching step will be described in detail.

1. King water leaching process

Waste refractory bricks from a melting furnace for manufacturing LCD (Liquid Crystal Display) glass including platinum group metals are charged into a jaw closure and crushed. The refractory bricks crushed through the jaw closure are classified into low-grade platinum / rhodium, Leach. Scrap containing platinum and rhodium does not need to be crushed separately, so it leaches directly into the water.

Aqua regia, a mixed acid of hydrochloric acid and nitric acid, is used to elute the platinum group metals present in scrap or refractory bricks to elute the poorly soluble platinum group elements.

The leach method by the royal flush water has the following reaction.

[Reaction Scheme 1]

_{Pt + 18HCl + 2HNO 3 = H} 2 PtCl 6 + 4H 2 O + 2NOCl

However, the method of leaching by the water of aquatic organisms requires a very long processing time and is limited by the total nitrogen (TN) restriction item for the use of nitric acid.

2. Electrolyaching process

A scrap of a platinum-rhodium alloy sheet containing a low-grade platinum group metal is prepared by crushing a waste refractory brick of a melting furnace for producing an LCD glass containing a platinum group metal and melted in a vacuum induction melting furnace to prepare an electrode for electrolytic leaching, Is used as an electrolytic electrode of an electrolytic leaching apparatus to leach platinum group metals to carry out pretreatment steps necessary for separation and purification.

It is possible to reduce the process time by leaching low quality platinum / rhodium alloy sheet or waste refractory brick by electrode and electrolytic method, and it is expected to shorten the whole process time by directly separating leached platinum ion and rhodium ion by ion exchange method. .

The present invention relates to an electrolytic leaching method in which a low-grade platinum-rhodium alloy sheet or a refractory brick is electrolytically converted into a sheet form through primary processing, hydrochloric acid is used as an extrusion liquid for leaching the same, and alternating current (AC) And the like. Through the above method, it is possible to reduce the amount of acid and energy used in the leaching and refining process, reduce the generation of wastewater containing lead and waste acid, reduce the amount of NOx-containing waste gas generated during the refining process, It is possible to purify a large amount continuously without repeated operation.

In the case of scrap of a platinum-rhodium alloy sheet discharged from a melting furnace for producing an LCD (Liquid Crystal Display) glass, it is melted in a vacuum induction melting furnace, rolled, formed into a sheet, and electrolytically leached.

Hydrochloric acid (HCl) is used as the electrolyte (electrolyte) of the electrolytic leaching apparatus and two low-grade platinum group metal electrodes formed in the form of an ingot or a thin sheet in the electrolytic leaching tank It is connected to an AC power source and supplies a power source with a proper current density to leach platinum and rhodium and other impurities and platinum group metals into the leachate. During the electrolytic leaching process, hydrogen and chlorine gas generated from the two electrodes cause the adhesion of the platinum group metal around the electrodes, which leads to a decrease in contact with the leachate and a decrease in the leaching efficiency due to the concentration classification phenomenon It is preferable to carry out the reaction while agitating the leach solution in the settling tank with a stirrer so that an efficient reaction is achieved.

2 is a view schematically showing an electrolytic leaching apparatus according to an example.

2, the electrolytic leaching apparatus includes an electrolytic sedimentation tank 10 storing the leachate 15 and having acid-resistant characteristics, an electrode 20 made of a platinum group metal, an AC power supply unit 30 supplying AC power, A connecting portion 40 connecting the electrode 20 and the AC power supply portion 30 with connecting means such as bolts and nuts 44 and 46 and a stirrer 50 for stirring the inside of the electrolytic settling tank 10 And may further include a stirrer fixing unit 60 capable of fixing the stirrer 50 and a lid 70 for sealing the electrolytic settling tank 10. The connecting unit 40 and the agitator The valve 60 is configured to be coupled to the lid 70. A discharge port 90 for removing hydrogen and chlorine gas generated as the reaction proceeds may be separately provided.

FIG. 3 is a view showing in detail a part of an electrolytic leaching apparatus according to an example.

Referring to FIG. 3, a power source fixing plate 42 for fixing the AC power source electrode 32 for supplying AC power is fixed to the lid 70 of the electrolytic leaching apparatus E101 using bolts 44. As shown in FIG. At this time, the electrode 32 is connected to the power source fixing plate 42 through the bolt 44a and the nut 46b, and the platinum group metal electrode 20 processed to be used as the electrode is connected to the bolt 22a and the nut 22b And is connected to the AC power source electrode 32 by using this. The platinum group metal electrode 20 is introduced into the electrolytic sedimentation tank 10 filled with the leach solution (or electrolytic solution), and the leaching reaction proceeds while stirring the leach solution by the agitator 50 connected through the stirrer fixing portion 60. At this time, in order to prevent the platinum group metal electrode 20 from contacting with the electrodes due to agitation during the leaching reaction, a support stand 26 for preventing insolubility, acid resistance and conduction can be provided. In addition, an exudate injecting portion 80 and an exuding liquid discharging portion 85 are attached to facilitate the circulation of the exuding liquid.

The concentration of hydrochloric acid used as the leach solution is preferably about 4 to 12M. The agitator 50 for removing hydrogen and chlorine gas which is generated on the surfaces of the two platinum group metal electrodes 20 during the leaching reaction to lower the rate and efficiency of the leaching reaction includes a magnetic stirrer A magnetic stirrer or a mechanical stirrer can be applied. When a mechanical stirrer is used, the stirrer fixing unit 60 can be omitted from the configuration of the electrolytic leaching apparatus.

As the electrolytic leaching reaction proceeds, the leaching efficiency is lowered due to the consumption of hydrogen ions and chlorine ions. Therefore, a device capable of providing a more efficient leaching process by adding a device for adjusting the pH of the leaching solution by supplementing hydrochloric acid into the leaching solution Respectively.

Referring to FIG. 4, the temperature of the electrolytic sedimentation tank 10 is constantly maintained by the constant temperature circulating water tank C1 during the leaching process in the electrolytic leaching apparatus E101 indicated by the dotted line. In order to prevent the reduction of the contact area with the leachate (or electrolytic solution) due to the adhesion phenomenon caused by the hydrogen and chlorine gas generated at the two electrodes and the deterioration of the leaching efficiency due to the concentration classification phenomenon, ) So that the leach solution is stirred and circulated.

The circulation process of the leaching solution in the electrolytic settling tank 10 is carried out by using the pump P103 to change the hydrogen ion concentration of the leaching solution consumed by the hydrogen ions and the chlorine ions as the leaching progresses and the hydrochloric acid in the hydrochloric acid storage tank T102 into the first leaching solution tank T101 ) To control the concentration of hydrogen ions. At this time, the concentration of the hydrogen ions is adjusted by using the pH controller (PM1) installed in the first leach solution tank (T101). The leachate of the first leachate tank T101 having the hydrogen ion concentration adjusted is transferred to the electrolytic leaching apparatus E101 through the pump P101 attached to the first leachate tank T101, Is transferred to the first leachate storage tank (T101) through the pump (P102) connected to the electrolytic leaching apparatus (E101) for removal, and the concentration of hydrogen ions is controlled to circulate the liquid to increase the leaching efficiency. Further, in order to remove impurities generated in the leaching step, a step of removing impurities by passing the liquid transferred to the first leachate reservoir T101 through a reactor filled with a strongly acidic cation exchange resin to a cylindrical reactor can be added.

3. Platinum-rhodium separation purification process by ion exchange

The platinum and rhodium ions contained in the leachate stored in the leachate reservoir through the electrolytic leaching process or the royal leach leaching process are passed through an ion exchange column filled with an anion exchange resin to react the ion exchange reaction between the filled anion exchange resin and the leachate Platinum and rhodium can be separated. Through the leaching process, the platinum and rhodium metal present in the ionic state are adsorbed on the anion exchange resin by the ion exchange reaction and are separated from the rhodium.

The separation of platinum and rhodium from the ion exchange reaction can be carried out by adsorbing the platinum and rhodium of the leachate stored in the leachate reservoir from the leaching process in the form of an anion, respectively, using an anion exchange resin as shown in Table 1 below. It is possible to recover from the solution in an ionic state.

Platinum (Pt) Rhodium (Rh) Pt (II) [PtCl _4] ^2- Rh (III) [RhCl ₆ ] ^3-
_{[RhCl 5 (H 2 O)} ] 2-
_{[RhCl 4 (H 2 O)} 2] - Pt (IV) [PtCl ₆ ] ^2- Rh (IV) [RhCl ₆ ] ^2-

The adsorption of platinum and rhodium ions on anion exchange resin is as follows.

[Reaction Scheme 2]

nR + Cl ^- + [MCl ₆ ] ^{n -} ↔ [R] _n [MCl ₆ ] + nCl ^-

Here, M is a platinum group metal.

In addition, the affinity of the platinum and rhodium compounds with the anion exchange resin appears as [MCl ₆ ] ^2- > [MCl ₄ ] ² -> [MCl ₆ ] ^3- .

However, considering the oxidation potential characteristics of platinum and rhodium, anion exchange resins can decompose rhodium chloride and platinum chloride in an anion state. Among the two ions, rhodium chloride has an ion exchange reaction to the anion exchange resin at a higher rate than platinum. However, due to the ionization tendency and the driving force due to the concentration difference, the platinum ions are converted into rhodium ions and re- Exchange reaction to desorb rhodium chloride ions. Therefore, only the platinum ion remains in the ion exchange resin, and the rhodium ion exists in the solution passing through the ion exchange column, so that the two ions are efficiently separated. Also, the greater the ratio of the two ion concentrations, the greater the recovery of recovered platinum ions. This is because the concentration is also a variable in the ion exchange reaction.

The separation and purification process of platinum and rhodium by ion exchange will be described in more detail with reference to FIG.

5, in order to prevent hydrogen ions and chlorine ion concentrations in the leaching solution from being reduced due to the generation of hydrogen gas and chlorine gas, which cause deterioration of electrolytic leaching efficiency during the leaching reaction, And the leach solution in the first leachate reservoir T101 is circulated continuously while the electrolytic leaching proceeds and the hydrogen ions and the chlorine ions insufficient in the leachate reservoir are supplemented by adding hydrochloric acid. The leaching solution in the first leachate tank T101 can be supplied into the electrolytic leaching tank 10 of the electrolytic leaching apparatus E101 by the metering pump P101 and the electrolytic leaching solution in the electrolytic leaching apparatus E101 The leachate is supplied to the first leachate reservoir T101 via the check valve SV32 by the metering pump P102, so that the leachate can be circulated.

After the electrolytic leaching represented by the dotted line or the leachate leaching process, the platinum-rhodium precipitate present in the ionic state was transferred to the second leachate reservoir (T201), and then the strong basic anion exchange resin It is selectively passed through a filled ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5). The selective passage can be made through the check valves (SV1, SV2, SV3, SV4, SV5). For example, it is possible to close the check valves SV2, SV3, SV4 and SV5 and open the check valve SV1 so that the leaching solution is supplied to the ion exchange column SPU1 using the metering pump P201, The valves SV1, SV3, SV4 and SV5 are closed and the check valve SV2 is opened so that the leaching solution can be supplied to the ion exchange column SPU2 by using the metering pump P201. When the leachate is supplied to the ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5), platinum is adsorbed on the anion exchange resin by the ion exchange reaction between the anion exchange resin and the platinum and rhodium in the ion exchange column, Can be stored in the purified liquid storage tank T202 through the exchange column (SPU1, SPU2, SPU3, SPU4, SPU5) and the cation removal column (CRU1).

When the leach solution containing platinum ions and rhodium ions stored in the second leachate tank T201 is supplied to the ion exchange column SPU1 via the check valve SV1, the platinum ions are introduced into the anion exchange resin of the ion exchange column SPU1 And the leach solution containing rhodium ions is supplied to the Cation Removal Unit (CRU) (CRU1) through the ion exchange column (SPU1) through the check valve (SV16) and filled with strongly acidic cation exchange resin And is supplied to the ion exchange column SPU2 through the check valve SV12. Cationic impurities other than rhodium ions present in the leach solution supplied to the cation removal column (CRU1) filled with strongly acidic cation exchange resin are filtered by the cation removal column (CRU1).

When the leachate is supplied to the ion exchange column SPU2 through the check valve SV2 or the check valve SV12, the platinum ion is adsorbed to the anion exchange resin of the ion exchange column SPU2, Passes through the exchange column SPU2 and is supplied to the cation removal column CRU1 via the check valve SV17 or to the ion exchange column SPU3 through the check valve SV13. Cationic impurities other than rhodium ions present in the leach solution supplied to the cation removal column (CRU1) are filtered by the cation removal column (CRU1).

When the leachate is supplied to the ion exchange column SPU3 through the check valve SV3 or the check valve SV13, the platinum ion is adsorbed to the anion exchange resin of the ion exchange column SPU3, Passes through the exchange column SPU3 and is supplied to the cation removal column CRU1 via the check valve SV18 or to the ion exchange column SPU4 via the check valve SV14. Cationic impurities other than rhodium ions present in the leach solution supplied to the cation removal column (CRU1) are filtered by the cation removal column (CRU1).

When the leachate is supplied to the ion exchange column (SPU4) through the check valve (SV4) or the check valve (SV14), the platinum ion is adsorbed to the anion exchange resin of the ion exchange column (SPU4) Passes through the exchange column SPU4 and is supplied to the cation removal column CRU1 via the check valve SV19 or to the ion exchange column SPU5 through the check valve SV15. Cationic impurities other than rhodium ions present in the leach solution supplied to the cation removal column (CRU1) are filtered by the cation removal column (CRU1).

When the leachate is supplied to the ion exchange column (SPU5) through the check valve (SV5) or the check valve (SV15), the platinum ion is adsorbed to the anion exchange resin of the ion exchange column (SPU5) Is passed through the exchange column (SPU5) and is supplied to the cation removal column (CRU1) through the check valve (SV20). Cationic impurities other than rhodium ions present in the leach solution supplied to the cation removal column (CRU1) are filtered by the cation removal column (CRU1).

The leachate containing rhodium ions supplied to the column for removing ions (CRU1) from which cationic impurities have been removed is supplied to and stored in the reflux tank T202 via the check valve SV31, or the check valve SV30 and the check valve 34 to the second leachate reservoir T201 or stored in the first leachate reservoir T101 through the check valve SV30 and the check valve 35 and stored. Storing the leach solution containing rhodium ions, through which the cationic impurities have been removed, through the cation removal column (CRU1) in the second leachate reservoir (T201) may cause the leachate to re- This is to separate and purify platinum ion and rhodium ion by ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5) and cation removal column (CRU1). Storing the leaching solution containing rhodium ions, which have passed through the cation removing column (CRU1) and removed the cationic impurities, in the first leaching solution reservoir (T101) is to reuse the leaching solution for electrolytic leaching because hydrochloric acid remains in the leaching solution .

The first leachate reservoir T101 and the refill liquid reservoir T202 may be connected to each other via check valves SV32 and SV33.

Through separation and purification of platinum and rhodium by ion exchange, rhodium ions stored in the third leachate tank (T202) can be recovered through a substitution reaction or electrowinning, ion exchange, ion exchange resin incineration, rhodium leaching dissolution, Can be recovered by reduction reaction, precipitation calcination.

6 is a view showing a process of separating and purifying platinum and rhodium by ion exchange according to another example.

6, the platinum-rhodium leachate present in the ionic state through the electrolytic leaching process indicated by the dashed line is transferred to the second leachate tank T201, and then the metering pump P201 is used to remove the cation- (SPU1, SPU2, SPU3, SPU4, SPU5) filled with a strongly basic anion exchange resin after passing through the column (CRU1) to remove other cations present in the leach solution. The selective passage can be made through the check valves (SV1, SV2, SV3, SV4, SV5). For example, the check valves SV2, SV3, SV4, and SV5 may be closed and the check valve SV1 may be opened to allow the leachate having passed through the cation removal column CRU1 to be supplied to the ion exchange column SPU1 , The check valves SV1, SV3, SV4 and SV5 are closed and the check valve SV2 is opened so that the leachate having passed through the cation removal column CRU1 is supplied to the ion exchange column SPU2. When the leachate is supplied to the ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5), the anion exchange resin in the ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5) Adsorbed on the anion exchange resin, and rhodium ions can be stored in the purified liquid storage tank T202 through the ion exchange column.

When the leachate containing platinum ion and rhodium ion passed through the cation removal column (CRU1) is supplied to the ion exchange column (SPU1) through the check valve (SV1), the platinum ion is removed from the anion exchange resin And the leaching solution containing rhodium ions is supplied to the ion exchange column SPU2 through the check valve SV12 through the ion exchange column SPU1 or through the ion exchange column SPU1 to the check valve SV16 And is supplied to the purified liquid reservoir T202 via the check valve 31 and stored or is supplied to the second leachate reservoir T201 through the check valve SV16, the check valve 30 and the check valve 34 Or stored and supplied to the first leachate reservoir T101 through the check valve SV16, the check valve SV30 and the check valve 35 and stored. Storing the leachate in the second leachate reservoir (T201) may cause the leachate to return to the cation removal column (CRU1) and the ion exchange column (SPU1, SPU2, SPU3, SPU4, SPU5) to separate and purify platinum and rhodium ions. Storing the leachate in the first leachate reservoir (T101) is for the purpose of reusing leachate for electrolytic leaching because hydrochloric acid remains in the leachate.

When the leachate is supplied to the ion exchange column SPU2 through the check valve SV2 or the check valve SV12, the platinum ion is adsorbed to the anion exchange resin of the ion exchange column SPU2, Is supplied to the ion exchange column SPU3 through the check valve SV13 through the exchange column SPU2 or through the ion exchange column SPU2 and through the check valve SV17 and the check valve 31, Or may be supplied to and stored in the second leachate tank T201 through the check valve SV17, the check valve 30 and the check valve 34 or may be supplied to the check valve SV17, SV30 and check valve 35 to the first leachate reservoir T101 and stored.

When the leachate is supplied to the ion exchange column SPU3 through the check valve SV3 or the check valve SV13, the platinum ion is adsorbed to the anion exchange resin of the ion exchange column SPU3, Is supplied to the ion exchange column SPU4 via the check valve SV14 through the exchange column SPU3 or the ion exchange column SPU3 through the check valve SV18 and the check valve 31, Or may be supplied to and stored in the second leachate tank T201 through the check valve SV18, the check valve 30 and the check valve 34 or may be supplied to the check valve SV18, SV30 and check valve 35 to the first leachate reservoir T101 and stored.

When the leachate is supplied to the ion exchange column (SPU4) through the check valve (SV4) or the check valve (SV14), the platinum ion is adsorbed to the anion exchange resin of the ion exchange column (SPU4) Is supplied to the ion exchange column SPU5 through the check valve SV15 through the exchange column SPU4 or the ion exchange column SPU4 through the check valve SV19 and the check valve 31, Or may be supplied to and stored in the second leachate tank T201 via the check valve SV19, the check valve 30 and the check valve 34 or may be supplied to the check valve SV19, SV30 and check valve 35 to the first leachate reservoir T101 and stored.

When the leachate is supplied to the ion exchange column (SPU5) through the check valve (SV5) or the check valve (SV15), the platinum ion is adsorbed to the anion exchange resin of the ion exchange column (SPU5) The check valve SV20 and the check valve 34 through the check valve SV20 and the check column valve SP20 and the exchange column SPU5 via the check valve SV20 and the check valve 31, Or stored in the second leachate tank T201 through the check valve SV20, the check valve SV30 and the check valve 35 or is supplied to the check valve SV11) to the ion exchange column (SPU1).

FIG. 7 is a graph showing the relation between the amount of the rhodium ion and the amount of the rhodium ion in the ion-exchange column after the adsorption of platinum ions, An electrolytic sampling tank E201 for collecting the ions, a metering pump P301 for transferring the solution after electrolytic collection to the storage tank T301, and an electrolytic solution storage tank T301 for storing the solution.

The anion exchange resin adsorbing platinum through the separation and purification process of platinum and rhodium by ion exchange as above is incinerated at 650 ° C. or higher using a heating furnace.

The incinerated product is leached using aqua regia. In order to elute the poorly soluble platinum group elements, a mixed acid of hydrochloric acid and nitric acid, aqua regia, is used to elute the platinum group metals present in the incinerated product.

After the platinum group metal is leached out using the water, the denitrification step is carried out. The denitrification process is a process in which nitric acid is removed by heating the acid solution by heating. When the acid solution is firstly evaporated by heating, the process of adding the hydrochloric acid solution and evaporating the solution again may be repeated one to five times to completely remove the nitric acid component.

After the denitrification process, it can be recovered as a metal using a reducing agent such as ammonium chloride (NH ₄ Cl) or hydrazin (NH ₂ NH ₂ ) through the following reduction reaction.

[Reaction Scheme 3]

2 NH ₄ Cl + [PtCl ₆ ] ^{2 -} [NH ₄ ] ₂ [PtCl ₆ ] _(s) + ² Cl ^-

During the reduction process, platinum reacted with ammonium chloride (NH ₄ Cl) forms a precipitate.

The precipitate (reduction product) obtained through the reduction reaction is filtered and then calcined using a heating furnace to obtain a sponge-type platinum. The calcination is preferably carried out at a temperature of about 500 to 1000 ° C.

Casting of the sponge-type platinum as a result of the calcination finally results in obtaining a platinum ingot, which can be processed to be reused as a raw material for the alloy of platinum and rhodium or a secondary processed product.

After the denitrification process, the platinum may be recovered through a substitution reaction. As a method for reducing the product obtained through the denitrification process to a metal, the metal can be recovered by a substitution reaction with a focus on the redox potential. Platinum and rhodium can be recovered using copper (Cu) or zinc (Zn) to effectively remove iron (Fe) present in the mixed solution in the substitution reaction. In this case, since the substitution reaction takes place in a strongly acidic region, the substitution reaction and the copper dissolution reaction can proceed together with the high acidity. Therefore, it is preferable to add urea to the substitution solution to increase the acidity slightly to prevent loss of copper plate.

After the denitrification step, the platinum may be recovered through electrolytic recovery (or electrolytic recovery). The electrolytic recovery can be performed by a generally known method, and therefore, a detailed description thereof will be omitted here.

Rhodium separated from platinum and present in a liquid phase can be recovered by casting with an ingot through a substitution reaction or electrolytic recovery (or electrolytic recovery), or by ion exchange, ion exchange resin incineration, rhodium leaching dissolution, reduction reaction, precipitation calcination It can be recovered by casting it into an ingot.

Hereinafter, experimental examples according to the present invention will be specifically shown, and the present invention is not limited by the following experimental examples.

<Experimental Example 1>

(Pt) -Radium (Rh) sheet made of a platinum (Pt) and rhodium (Rh) alloy in sheet form was used for evaluation of the electrolytic leaching efficiency according to the current and the composition of the leaching solution. Was connected to the AC power supply unit 30 of the electrolytic cell E101 at a pole distance of 40 mm and the electrolytic sedimentation tank 10 was fed with the electrolytic solution 15 and then the electrolytic solution 15 was fed through the stirrer 50 And an alternating current was applied at a current density of 0.245 A / cm &lt; ² &gt; min to agitate. At this time, 1 L of reagent grade hydrochloric acid (35%) was used as the leaching solution for leaching the sheet of platinum (Pt) - rhodium (Rh), and the weight of the electrode was measured when leaching was completed.

<Experimental Example 2>

With the current density applied to 0.592A / cm ² · min, - platinum (Pt) and rhodium (Rh) electrode to produce the alloy sheet (Sheet) type 20 (rhodium (Rh) sheet platinum (Pt)) A platinum (Pt)-rhodium (Rh) sheet was leached under the same conditions as in Experimental Example 1 using only hydrochloric acid (35%) as the leach liquor 15 in the electrolytic settling tank 10.

<Experimental Example 3>

The current density was set to 0.381 A / cm ² .multidot.min to leach out the electrode 20 (platinum (Pt) - rhodium (Rh) sheet) made of a sheet type of platinum (Pt) and rhodium (Rh) (35%) was mixed with deionized water at a ratio of 4: 6 to prepare 1 L of leachate (15).

<Experimental Example 4>

The ratio of hydrochloric acid (35%) to deionized water used as the leach liquor 15 in the electrolytic settling tank 10 was 5: 5 and an alternating current was applied at a current density of 0.379 A / cm ² · min. A platinum (Pt)-rhodium (Rh) sheet was leached under the same conditions.

<Experimental Example 5>

With the current density applied to 0.627A / cm ² · min, - platinum (Pt) and rhodium (Rh) is manufactured in an alloy sheet (Sheet) electrodes (20, rhodium (Rh) sheet platinum (Pt)) A platinum (Pt)-rhodium (Rh) sheet was leached under the same conditions as Experimental Example 1, using a ratio of hydrochloric acid (35%) to deionized water as the leaching solution in the electrolytic settling tank 10 at 7:

<Experimental Example 6>

With the current density applied to 0.592A / cm ² · min, - platinum (Pt) and rhodium (Rh) is manufactured in an alloy sheet (Sheet) electrodes (20, rhodium (Rh) sheet platinum (Pt)) A platinum (Pt)-rhodium (Rh) sheet was leached under the same conditions as in Experimental Example 1 using a ratio of hydrochloric acid (35%) to deionized water of 7: 3 as the leachate 15 in the electrolytic settling tank 10 .

<Experimental Example 7>

With the current density applied to 0.623A / cm ² · min, - platinum (Pt) and rhodium (Rh) is manufactured in an alloy sheet (Sheet) electrodes (20, rhodium (Rh) sheet platinum (Pt)) Rhodium (Rh) sheet was leached under the same conditions as Experimental Example 1 using a ratio of hydrochloric acid (35%) to deionized water of 6: 4 as the leach liquor (15) in the electrolytic settling tank (10) Respectively.

<Experimental Example 8>

With the current density applied to 0.344A / cm ² · min, - platinum (Pt) and rhodium (Rh) is manufactured in an alloy sheet (Sheet) electrodes (20, rhodium (Rh) sheet platinum (Pt)) Rhodium (Pt) -horimium (Rh) sheet was leached under the same conditions as Experimental Example 1 using the ratio of hydrochloric acid (35%) to deionized water as the leach liquor (15) in the electrolytic settling tank (10) Respectively.

As a result of leaching of platinum (Pt) - rhodium (Rh) through the experimental examples of the present invention, the volume of the leaching solution was reduced due to the hydrogen and chlorine gas generated during the reaction at the electrode, and the hydrogen ion concentration The leaching efficiency was decreased. For this purpose, the reduction of the leaching efficiency in the electrolytic sedimentation tank 10 due to the decrease of the hydrogen ion concentration in the leaching solution is prevented, and the leaching solution is circulated and the platinum-rhodium sheet is efficiently leached to correct the hydrogen ion concentration of the leaching solution there was.

The greater the intensity of the current applied to the reactor, the greater the leaching efficiency. However, the leaching efficiency of only 70% diluted hydrochloric acid and 100% hydrochloric acid is directly proportional to the concentration. However, it is effective to use only 100% hydrochloric acid because it is efficient to use a high concentration of leachate when considering operation with a high concentration leachate for a long time for leaching. In the case of platinum / rhodium alloy having a composition ratio of about 99.9% and a ratio of 80:20, the leaching efficiencies were similar. Table 2 shows the results of the above experimental examples.

Current density (A / cm &lt; 2 &gt; min) Leaching amount (g) Leaching Rate (mg / A) Leaching time (min) Experimental Example 1 0.245 0.89 0.90 140 Experimental Example 2 0.592 2.29 0.95 120 Experimental Example 3 0.381 0.49 0.32 120 Experimental Example 4 0.379 0.62 0.40 120 Experimental Example 5 0.627 2.28 0.89 120 Experimental Example 6 0.592 0.96 0.40 120 Experimental Example 7 0.623 1.70 0.67 120 Experimental Example 8 0.344 1.07 0.77 120

Separation of platinum and rhodium was carried out from a mixed solution of platinum and rhodium by ion exchange as follows.

<Experimental Example 9>

(SPU) composed of resin towers filled with strongly basic anion exchange resin and a cation removal column (CRU) filled with strongly acidic cation exchange resin were mixed with pH of the platinum- And platinum and rhodium were separated and purified.

When the pH of the platinum-rhodium mixed solution is more than 1.5, it is difficult to separate platinum and rhodium because the platinum is adsorbed to the anion-exchange resin from the mixed solution by the ion exchange reaction and the adsorption of rhodium ions occurs at the same time. In addition, rhodium can be separated from the anion exchange resin adsorbed by regeneration with hydrochloric acid. However, in the regeneration process, some platinum ions are separated and the separated liquid composition is similar to the initial mixture in which platinum and rhodium are present together, Which may cause deterioration of separation efficiency.

<Experimental Example 10>

Platinum and rhodium were separated and purified by varying the concentration of the treatment solution in an ion exchange column (SPU) as in Experimental Example 9.

The separation of platinum and rhodium by ion exchange reaction was relatively easy when the leachate, which had a concentration of about 3 g per liter in the ion exchange column, was injected at an appropriate flow rate. On the other hand, when the concentration is more than 10 g / liter, the reaction with the anion exchange resin can not be performed sufficiently, and the amount of treatment of the anion exchange resin is smaller than that of the anion exchange resin, and the efficiency of separation of platinum and rhodium is also decreased.

&Lt; Experimental Example 11 &

Platinum and rhodium were separated and purified by varying the flow rate of the treatment solution in an ion exchange column (SPU) as in Experimental Example 10.

If the flow rate of the treatment liquid supplied to the ion exchange column is about 20 times or less the volume of the ion exchange column per hour, about 200 g of platinum ion per unit volume (1 L) anion exchange resin can be adsorbed. Only the rhodium ions remain in the solution passing through the ion exchange column, so that the rhodium ions can be effectively separated.

The reduction reaction was performed as follows to recover platinum and rhodium separated in the form of metal by ion exchange.

<Experimental Example 12>

After platinum ions adsorbed by ion exchange reaction were leached into the water, the precipitated platinum was recovered by adding ammonium chloride (NH ₄ Cl) to the platinum - concentrated solution subjected to the denitrification process.

The ammonium chloride (NH ₄ Cl) used in the reduction reaction was added to the platinum concentrate at a concentration of 219 g / L to obtain a precipitate of [NH ₄ ] ₂ [PtCl ₆ ] through a reduction reaction. The precipitate was filtered , And the sponge-type platinum was recovered by calcining at 1200 ° C. or more for 2 hours or more. The precipitate was diluted ammonium chloride (NH ₄ Cl) solution for washing with water.

<Experimental Example 13>

Platinum ions adsorbed by ion - exchange reaction were leached into aqua regia, and then the metal was recovered by a substitution reaction considering the redox potential by a method for reducing the platinum - concentrated solution from the denitrification process to metal.

Platinum and rhodium were recovered using copper (Cu) in order to effectively remove iron (Fe) present in the mixture in the substitution reaction. In this case, since the substitution reaction takes place in a strongly acidic region, the substitution reaction and the copper dissolution reaction can proceed together with the high acidity. Therefore, it is preferable to add urea to the substitution solution to increase the acidity slightly to prevent loss of copper plate.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, This is possible.

10: Electrolytic sedimentation tank 15: Leachate
20: Electrode of platinum group metal 26:
30: AC power supply unit 32: AC power supply electrode
40: connection part 42: power fixing plate
22a, 44, 44a: bolts 22b, 46, 46b: nuts
50: stirrer 60: stirrer fixing unit
70: lid 80:
85: Leachate discharging part E101: Electrolytic leaching device
P101, P102, P103, P201, P202: Quantitative pump
T101: first leachate tank T102: hydrochloric acid storage tank
PM1: pH meter T201: Second leachate reservoir
T202: Purified liquid storage tank E201: Electrolytic collection tank
T301: Electrolyte storage tank
The check valve is provided with a check valve (not shown), which is connected to the check valve

Claims (13)

(a) leaching or electrolytically leaching a scrap containing platinum and rhodium or a waste refractory brick containing platinum and rhodium, to dissolve the platinum group metal;
(b) adsorbing platinum on an anion exchange resin through an ion exchange column packed with a strong basic anion exchange resin, the leaching solution having the platinum group metal leached and dissolved therein;
(c) incinerating the platinum-adsorbed anion exchange resin;
(d) leaching and dissolving platinum in the incinerated product;
(e) heating and evaporating the dissolved product to perform a denitrification process; And
(f) recovering platinum by calcination of the precipitate obtained by reduction reaction of the product obtained through the denitrification process, or recovering platinum metal through a substitution reaction using a difference in redox potential, And recovering the platinum by electrolytic recovery of the resultant product subjected to the denitrification step.
The method of claim 1, further comprising, before step (b) after step (a)
Further comprising the step of removing the cationic impurities by passing the leached solution of leached platinum group metal to recover more purified platinum through a cation removal column packed with strongly acidic cation exchange resin .
The method of claim 1, wherein after step (b), before step (c)
Passing the leaching solution passed through the ion exchange column through a cation removal column packed with a strongly acidic cation exchange resin to remove cation impurities; And
And recovering rhodium ions from the leachate having passed through the cation removal column.
2. The method of claim 1, wherein a plurality of the ion exchange columns are connected, and the leaching solution is continuously passed through a plurality of ion exchange columns so as to adsorb the platinum on the anion exchange resin, so as to increase the recovery rate of platinum. Lt; / RTI &gt;
The method according to claim 1,
Hydrochloric acid (HCl) is used as the leaching solution necessary for electrolytic leaching, and hydrochloric acid (HCl) having a concentration of 4 to 12 M is used,
In order to remove the hydrogen gas and the chlorine gas which cause deterioration of the electrolytic leaching efficiency during the electrolytic leaching reaction, the leaching solution was stirred using an agitator to circulate the leaching solution in the electrolytic sedimentation tank, Leaching metals,
In order to prevent decrease of the hydrogen ion and chlorine ion concentration in the leaching solution due to the generation of hydrogen gas and chlorine gas which cause deterioration of the electrolytic leaching efficiency during the electrolytic leaching reaction, the leaching solution in the electrolytic leaching tank and the leaching solution of the leaching solution tank And recovering platinum group metal by replenishing hydrochloric acid to the leachate reservoir while circulating continuously during electrolytic leaching.
The method of claim 1, wherein the leaching solution for electrolytic leaching is maintained at pH equal to or less than 1.5,
In order to maintain pH of the leach solution, a pH controller is attached to the first leachate reservoir, and hydrochloric acid is supplied quantitatively from the hydrochloric acid reservoir to the first leachate reservoir, and the leachate is circulated while hydrochloric acid is replenished to the leachate reservoir to leach platinum group metal And recovering the platinum group metal.
The method according to claim 1, wherein in the step (f)
Ammonium chloride (NH ₄ Cl) or hydrazin (NH ₂ NH ₂ ) is used as a reducing agent for the reduction reaction,
Wherein zinc (Zn) or copper (Cu) having a larger oxidation-reduction potential than the platinum group metal is used for the substitution reaction.
A leaching apparatus for leaching platinum group metals;
A first leachate reservoir for supplying the leachate to the leaching tank of the leaching apparatus;
A second leachate reservoir for storing the leach solution in which the platinum group metal is leached and dissolved;
An ion exchange column packed with a strongly basic anion exchange resin supplied from the second leachate storage tank for adsorbing platinum, and an ion exchange column filled with a leachate solution in which a platinum group metal is leached and dissolved;
A cation removal column packed with a strongly acidic cation exchange resin for receiving and removing cationic impurities from the leachate passed through the ion exchange column; And
And a refill liquid reservoir for storing the leachate which has passed through the cation removal column.
A leaching apparatus for leaching platinum group metals;
A first leachate reservoir for supplying the leachate to the leaching tank of the leaching apparatus;
A second leachate reservoir for storing the leach solution in which the platinum group metal is leached and dissolved;
A cation removal column packed with a strongly acidic cation exchange resin for absorbing and removing cationic impurities from the second leachate reservoir, the leach solution containing leached platinum group metals dissolved therein;
An ion exchange column filled with a strongly basic anion exchange resin for receiving the leach solution having passed through the cation removal column and adsorbing platinum; And
And a refill liquid reservoir for storing the leachate having passed through the ion exchange column.
10. The method according to claim 8 or 9,
Further comprising a hydrochloric acid reservoir for quantitatively supplying hydrochloric acid to the first leachate reservoir for maintaining the pH of the leachate,
The leaching apparatus is an electrolytic leaching apparatus,
The electrolytic leaching apparatus includes:
An electrolytic settling tank storing the leachate and having acid resistance characteristics;
An electrode made of a platinum group metal to be leached;
An AC power supply unit for supplying AC power;
A connection unit connecting the electrode and the AC power supply unit; And
And an agitator for agitating the inside of the electrolytic precipitation tank,
In order to prevent reduction of the hydrogen ion and chlorine ion concentration in the leaching solution due to the generation of the hydrogen gas and the chlorine gas which cause deterioration of electrolytic leaching efficiency during the leaching reaction, the leaching solution in the electrolytic leaching tank and the leaching solution in the first leaching solution reservoir Is circulated continuously while electrolytic leaching proceeds, hydrochloric acid is replenished in the first leachate reservoir,
Hydrochloric acid (HCl) is used as the leaching solution, and hydrochloric acid (HCl) having a concentration of 4 to 12M is used,
Wherein the leachate for electrolytic leaching is maintained at pH equal to or less than 1.5.
The ion exchange apparatus according to claim 8, wherein a plurality of said ion exchange columns are connected,
A check valve is provided at the input end of each ion exchange column to selectively block the inflow of the leachate,
A check valve is provided at the output end of each ion exchange column to selectively block the outflow of the leachate,
The leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column,
A check valve for selectively supplying the leachate having passed through the cation removal column to the reflux liquid storage tank is provided at the output end of the column for removing cation,
A check valve for supplying the leachate having passed through the cation removal column to the first leachate reservoir is provided at the output end of the cation removal column,
And a check valve for supplying the leachate having passed through the cation removal column to the second leachate reservoir is provided at the output end of the cation removal column.
10. The ion exchange apparatus according to claim 9, wherein a plurality of said ion exchange columns are connected,
A check valve is provided at the input end of each ion exchange column to selectively block the inflow of the leachate,
A check valve is provided at the output end of each ion exchange column to selectively block the outflow of the leachate,
The leach solution is configured to selectively pass through a plurality of ion exchange columns through a check valve provided at an input end and an output end of each ion exchange column,
A check valve for selectively supplying the leaching solution having passed through the last-stage ion-exchange column out of the plurality of ion-exchange columns to the refill liquid reservoir is provided at the output end of the ion-
A check valve is provided at the output end of the ion exchange column at the final stage for supplying the leach solution having passed through the final stage ion exchange column among the plurality of ion exchange columns to the first leach solution reservoir,
A check valve is provided at the output end of the ion-exchange column at the final stage for supplying the leachate having passed through the last-stage ion-exchange column among the plurality of ion-exchange columns to the second leachate reservoir,
A check valve is provided at the output end of the ion-exchange column at the final stage for supplying the leaching solution having passed through the final-stage ion-exchange column among the plurality of ion-exchange columns to the ion-exchange column at the first stage among the plurality of ion-exchange columns Wherein the platinum group metal is recovered.
[12] The apparatus of claim 9, further comprising: an electrolytic collection tank for receiving the liquid stored in the refill liquid reservoir and recovering rhodium ions as rhodium metal;
A pump for transferring the liquid stored in the purified liquid storage tank to the electrolytic collection tank;
An electrolytic extracting liquid reservoir supplied with the electrolytic extract liquid in the electrolytic sampling tank; And
Further comprising a pump for transferring the electrolytic solution collected in the electrolytic collection tank to the electrolytic solution storage tank.

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