KR101454645B1 - Method for quantitative analysis of metals from spent catalyst of exhaust gas consecration system - Google Patents

Abstract

The present invention relates to a waste catalyst discharged from an exhaust gas purifier; And a solvent containing fluoric acid, nitric acid, and hydrochloric acid, and a telerium solution, into a sealed container, and firstly heating the mixture using microwaves; Adding a solvent including sodium chloride, hydrochloric acid and telerium solution to the first mixed solution to form a second mixed solution; Injecting the second mixed solution into a hermetically sealed container and performing secondary heating using microwaves; Adding a solvent containing hydrochloric acid to the second mixed solution to form a third mixed solution; And quantifying the amount of the metal contained in the third mixed solution. The present invention relates to a method for quantifying a metal contained in a waste catalyst of an exhaust gas purifying apparatus. According to this, it is possible to perform analysis in a short time by reducing the temperature rise time of the spent catalyst by using the microwave, and to prevent the volatilization of the metal to the outside or the introduction of the foreign substance from the outside, .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for quantifying a metal included in a spent catalyst of an exhaust gas purification apparatus,

The present invention relates to a method for quantifying a metal included in a spent catalyst of an exhaust gas purifying apparatus, and more particularly, to a method for quantifying a metal included in a waste catalyst, And more particularly, to a method for accurately measuring the content of a metal contained in a spent catalyst by blocking the introduction of foreign matter.

Catalysts for automobile exhaust gas purifiers that discharge tens of thousands of tons annually around the world are loaded with fine platinum group metals that serve as catalysts in ceramic substrates. The platinum group precious metals vary depending on the type of automobile, It contains 1 ~ 2g per unit, and it contains 0.5 ~ 1g of platinum.

The platinum group metals rhodium, platinum and palladium are representative elements of the platinum group belonging to the eighth group in the periodic table and are excellent in chemical stability, heat resistance and corrosion resistance, and are not only a conductor for electricity or heat but also a catalyst for oxidation and hydrogenation And is used as a catalyst for purification of exhaust gas of automobiles.

Therefore, when the platinum group metal is recycled from the automobile waste catalyst, it is possible to reduce the dependence of the raw material on the foreign country and to achieve the import substitution effect. Thus, the method of quantifying the metal content of the spent catalyst and the method of recovering it, It is an important industry.

Techniques for recovery of platinum group metals contained in existing automobile waste catalysts can be classified into a dry smelting method and a wet smelting method, among which wet smelting is the most common method.

The wet smelting method is advantageous in that it can dissolve the entire amount of the spent catalyst itself by using a strong oxidizing chemical such as chlorine and then analyze the platinum group metal dispersed in the dissolved solution. There is a disadvantage that a reagent having a low recovery rate and a strong oxidizing power should be used.

As disclosed in Korean Patent Laid-Open Publication No. 2010-0124030 entitled "Leaching Method of Platinum Group Metal from Automobile Waste Catalyst" and Korean Patent Laid-Open Publication No. 2001-0107450 "Recovery Method of Platinum Group Metal from Waste Carbon Catalyst" It is necessary to proceed with four steps of Alkali fusion step, acidification step, silicate dehydration step, coprecipitation step, reduction step and coprecipitation method, It takes 3 to 4 days of analysis time per piece, which is not economical and is not applicable to industry.

Therefore, it is required to develop a method capable of quantifying the metal content and the recovery rate of the spent catalyst discharged from the exhaust gas purifying apparatus easily in a short time.

Korea Patent Publication No. 2010-0124030 Korean Patent Laid-Open No. 2001-0107450

The present invention can reduce the temperature rise time of the spent catalyst and enable analysis in a short time, and can prevent the volatilization of the metal to the outside or the introduction of foreign substances from the outside, And to provide a method for quantifying the content.

The present invention relates to a waste catalyst discharged from an exhaust gas purifier; And a solvent containing fluoric acid, nitric acid, and hydrochloric acid, and a telerium solution, into a sealed container, and firstly heating the mixture using microwaves; Adding a solvent including sodium chloride, hydrochloric acid and telerium solution to the first mixed solution to form a second mixed solution; Injecting the second mixed solution into a hermetically sealed container and performing secondary heating using microwaves; Adding a solvent containing hydrochloric acid to the second mixed solution to form a third mixed solution; And quantifying the amount of the metal contained in the third mixed solution. The present invention also provides a method for quantifying a metal contained in a waste catalyst of an exhaust gas purifying apparatus.

Hereinafter, a method for quantifying platinum and palladium of a spent catalyst according to a specific embodiment of the present invention will be described in detail.

The present inventors have found that a dry smelting method, which is one of techniques for recovering metals from a spent catalyst discharged from a conventional exhaust gas purifying apparatus, is harmful to the environment by using a strong oxidizing reagent for decomposing all the components, And the wet smelting method requires a large amount of energy to be supplied in order to obtain a good recovery rate and the analysis time is about 3-4 days.

Therefore, a method for quantifying the amount of metal and the recovery rate of the spent catalyst discharged from the exhaust gas purifying apparatus in a short time has been studied, and the reaction is conducted in a closed system using microwaves Invented a method for quantifying a metal contained in a spent catalyst capable of precise analysis in a short time.

In the method of quantifying the metal, the temperature of the spent catalyst is rapidly increased by using a microwave, the time required for the pretreatment of the sample can be reduced, the reaction proceeds in a closed system to prevent volatilization of acid and metal, It is possible to measure the accurate recovery rate by blocking the contamination.

In particular, the method of quantifying platinum and palladium of the spent catalyst can analyze 8 to 9 automobile waste catalysts at the same time, and the analysis time is short as several hours, so that platinum and palladium of the spent catalyst can be quantified quickly and easily .

According to an embodiment of the present invention, a waste catalyst discharged from an exhaust gas purification apparatus; And a solvent containing fluoric acid, nitric acid, and hydrochloric acid, and a telerium solution, into a sealed container, and firstly heating the mixture using microwaves; Adding a solvent including sodium chloride, hydrochloric acid and telerium solution to the first mixed solution to form a second mixed solution; Injecting the second mixed solution into a hermetically sealed container and performing secondary heating using microwaves; Adding a solvent containing hydrochloric acid to the second mixed solution to form a third mixed solution; And quantifying the amount of the metal contained in the third mixed solution. The method for quantifying a metal included in the waste catalyst of the exhaust gas purifying apparatus may be provided.

The spent catalyst is a catalyst discharged from an exhaust gas purifying apparatus and may include at least one metal compound selected from the group consisting of platinum and palladium. The platinum and palladium are platinum group elements, which are excellent in chemical stability, heat resistance, corrosion resistance, and have a high electrical conductivity and thermal conductivity, and can act as catalysts for purification of exhaust gas of automobiles by catalyzing oxidation and hydrogenation reactions.

The spent catalyst may further include rhodium, aluminum, cesium or magnesium in addition to platinum and palladium, and the platinum and palladium in the spent catalyst may be contained in a mass ratio of 2: 1 to 10: 1, preferably 3: 1 To 6: 1.

The first mixed solution may be prepared by adding a mixed solvent containing a hydrofluoric acid, nitric acid, and hydrochloric acid and a telerium solution to the spent catalyst discharged from the exhaust gas purifier. In the first mixed solution, the spent catalyst may be in a liquid state by reacting with the mixed acid and telerium solution.

More specifically, in the preparation of the first mixed solution, the reaction molar ratio of the mixed acid to the telarium solution may be 15: 1 to 2: 1, preferably 10: 1 to 5: 1. The mixed acid may be a mixture of hydrofluoric acid, nitric acid, and hydrochloric acid in a molar ratio of 1: 0.1 to 2: 10 to 20. In the first mixed solution, the coagulation can dissolve the solid components in the spent catalyst, and the telerium solution can reduce and / or precipitate the components of the spent catalyst. The telarium solution may be prepared by dissolving tellurium metal having a purity of 99% or more at 2,000 mg / L, and when the solution contains a telenium solution within the above range, reduction and precipitation are not performed smoothly The recovery rate of the metal in the spent catalyst may be low.

Particularly, in the method of quantifying the metal included in the waste catalyst, the components of the waste catalyst can be easily reduced and / or settled at a low temperature by using the mixed acid and telarium solution in the production of the first mixed solution, The sample can be pretreated with less energy than the dry or wet smelting method of the present invention, and the metal in the spent catalyst can be more efficiently quantitated by atomic emission spectroscopy or the like.

The solvent containing the mixed acid and telerium solution may be reacted in an amount of 30 to 100 ml, preferably 50 to 80 ml, per 1 g of the waste catalyst. When the solvent containing the mixed acid and telemium solution is contained in an excessively small amount, the waste catalyst may not completely dissolve and an error may occur in the quantitative analysis step. When the solvent is too much contained, Or the sample in the closed container overflows out of the container, resulting in an error due to the loss of the sample.

Then, the first mixed solution may be injected into a hermetically sealed container and firstly heated using microwave. The first heating step may be performed at a temperature of 80 to 100 atm and at a temperature of 180 to 210 DEG C for 100 to 150 minutes. The closed vessel may be a microwave vessel of Teflon which is stable at high temperature. Particularly, in the above-described quantitative method, the reaction proceeds in a closed vessel to prevent evaporation of added acid, prevent the loss of volatile metals, and prevent contamination from the outside, thereby enabling precise quantitative determination and recovery.

Next, a second mixed solution may be formed by adding a solvent including sodium chloride, hydrochloric acid, and telerium solution to the first mixed solution heated by using the microwave. The spent catalyst of the second mixed solution reacts with sodium chloride, hydrochloric acid, and telemium solution to generate chlorine gas, and the waste catalyst components reduced and / or precipitated in the first mixed solution can be converted into soluble salts In particular, palladium and platinum, which are platinum group metals contained in the spent catalyst, can be dissolved in the solvent.

More specifically, in the step of preparing the second mixed solution, sodium chloride may be contained in an amount of 1 to 3 g based on 1 g of the spent catalyst, and the molar ratio of the hydrochloric acid and the tellurium solution may be 2: 1 to 1: 2. In the second mixed solution, sodium chloride can convert the components of the spent catalyst into a soluble salt, and the hydrochloric acid can dissolve the metal of the spent catalyst. The telemium solution may be prepared by dissolving tellurium metal having a purity of 99% or more at 2,000 mg / L in the same manner as in the first mixed solution, And precipitation is not smoothly carried out, so that the recovery rate of the metal in the spent catalyst may be low.

Further, the solvent containing sodium chloride, hydrochloric acid, and telerium solution may be added in an amount of 1 to 30 ml per 1 g of the waste catalyst. When the solvent containing sodium chloride, hydrochloric acid, and telerium solution is contained in an excessively small amount, the waste catalyst may not be completely dissolved and an error may occur in the step of quantitative analysis. When too much is contained, An explosion may occur, or a sample in the closed container may overflow out of the container, resulting in an error due to the loss of the sample.

Then, the second mixed solution may be injected into a sealed container and then subjected to secondary heating using microwaves. The secondary heating may be performed at a temperature of 80 to 100 atm to 200 to 220 ° C for 100 to 150 minutes. The sealed vessel may be a microwave vessel of hydrochloric acid and a high-temperature stable Teflon. Particularly, in the above-described quantitative method, the reaction proceeds in a closed vessel to prevent evaporation of added acid, prevent the loss of volatile metals, and prevent contamination from the outside, thereby enabling precise quantitative determination and recovery.

Meanwhile, the first or second heating step using the microwave may further include raising the temperature of the first mixed solution and the second mixed solution to 150 ° C to 250 ° C, respectively. That is, the first mixed solution and the second mixed solution may be heated to 150 ° C to 250 ° C, and the first and second heating may be performed in the temperature and pressure ranges described above. Particularly, in the heating step, the time for raising the first mixed solution and the second mixed solution to a high temperature of 150 ° C to 300 ° C can be remarkably reduced to 10 minutes or less by using a microwave other than the other heat source, It is possible to shorten the time for analyzing the content of the metal.

The microwave used in the primary or secondary heating may have an output of 700 to 1,500 watts, preferably 1,000 to 1,200 watts. When the output of the microwave is 700 watts or less, the temperature rise of the spent catalyst may not be sufficient, or the time required for raising the temperature may be prolonged. When irradiated with an output of 1,500 watt or more, unnecessary high energy irradiation is uneconomical and various negative reactions may occur.

The method may further include a step of performing a primary or secondary heating using the microwave and then cooling at a temperature of -30 ° C to 70 ° C for 30 to 70 minutes. More preferably at a temperature of 40 to 60 DEG C for 10 to 30 minutes, and then to a second cooling at -10 to -30 DEG C for 20 to 40 minutes. The cooling step can stabilize the sample activated by the heating using the microwave, and can remove the nitrogen oxide (NOx) gas in the closed container, thereby more efficiently quantifying the content of the metal contained in the spent catalyst.

Next, a third mixed solution may be formed by adding a solvent containing hydrochloric acid to the second mixed solution which is secondarily heated using the microwave. The third mixed solution is prepared by reacting the second mixed solution with hydrochloric acid to make the components of the spent catalyst of the second mixed solution into a liquid state and quantifying the amount of the metal to be described later. can do.

The hydrochloric acid reacted with the second mixed solution in the step of forming the third mixed solution may be mixed with hydrochloric acid and nitric acid. The reaction molar ratio of hydrochloric acid to nitric acid may be 1: 5 to 1:20, and the hydrochloric acid or the mixture of hydrochloric acid and nitric acid may dissolve metal in the spent catalyst, particularly platinum and palladium, in a liquid state in the third mixed solution have.

Then, the amount of the metal contained in the third mixed solution can be quantified, and the atomic emission spectroscopy can be used as a quantitative analysis method. Atomic emission spectroscopy is an analytical method based on flame, electric arc, and electric spike atomization excitation. It is used for the analysis of metal elements. Specifically, it uses Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) The amount of the metal element can be quantified. The inductively coupled plasma atomic emission spectrometer is a device for quantitatively and qualitatively analyzing a specific element by measuring the wavelength and intensity of radiation emitted from each atom by exciting atoms with a high temperature argon plasma. . ≪ / RTI > Particularly, by quantifying the amount of the metal contained in the third mixed solution by using the inductively coupled plasma atomic emission spectrometer (ICP-AES), it is possible to precisely quantify platinum and palladium among the platinum group elements contained in the spent catalyst of the exhaust gas purifying apparatus can do.

The method of quantifying the metal included in the spent catalyst of the exhaust gas purifying apparatus of one embodiment can rapidly increase the temperature of the sample using a microwave to significantly reduce the time required for the analysis, In this closed system, the evaporation of the added acid is prevented, and the contamination from the outside is blocked, so that it is possible to measure the precise quantity and the recovery rate.

According to the present invention, the temperature rise time of the spent catalyst can be reduced and the analysis can be performed within a few hours, and the volatilization of the metal to the outside or the introduction of foreign matter from the outside can be blocked, A method of quantifying the metal content can be provided.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example ]

A standard reference material (SRM) containing 1,131 ± 11 mg / kg of platinum (Pt) and 233.2 ± 1.9 mg / kg of palladium (Pd) and having a pulverization size of 74 μm was prepared and stored at 105 ° C. Dried for 1 to 2 hours, and cooled for 30 minutes.

0.3 g of dried and cooled automotive waste catalyst scrap was placed in a teflon microwave vessel and 2 mL of hydrofluoric acid, 1 mL of nitric acid, 16 mL of hydrochloric acid and 2 mL of tellurium solution were injected, (TOP wave, Analytic Jena).

Then, the microwave vessel was taken out and cooled at a temperature of -18 ° C. to -20 ° C. for 30 minutes, and then 0.2 g of sodium chloride, 1 mL of hydrochloric acid and 2 mL of tellurium solution were injected, Secondary microwave digestion was performed under the operating conditions in Table 2.

Next, the microwave vessel was taken out and put in a temperature range of -18 ° C. to -20 ° C., and the mixture was cooled again for 30 minutes. The mixture was put into a 50 mL volumetric flask made of PP (polypropylene), adjusted to 3 mL with hydrochloric acid, The contents of platinum (Pt) and palladium (Pd) were analyzed by a coupled plasma atomic emission spectrometer (ICP-AES, Jobin yvon). The above procedure was repeated 5 times and the results are shown in Table 3 below.

The results of the microwave digestion analysis of the waste catalyst scraps of the automobile in Table 3 on the content of platinum and palladium contained in the SRM (standard material) of the automobile waste catalyst scrap were expressed as recovery, and the results are shown in Table 4 Respectively.

Temperature pressure Temperature rise time time Power 180 to 210 DEG C 90 5 minutes 120 minutes 1,000 to 1200 watts 50 ℃ 0 5 minutes 20 minutes 0 watts

Temperature pressure Temperature rise time time Power 200 ~ 220 ℃ 90 5 minutes 120 minutes 1,000 to 1200 watts 50 ℃ 0 5 minutes 20 minutes 0 watts

Number of measurements Platinum (mg / kg) Palladium (mg / kg) One 1,096.3 239.6 2 1,080.3 235.2 3 1,082.1 240.4 4 1,094.5 241.5 5 1,084.1 241.8 Average 1,087.5 239.7

car
Waste catalyst scrap Platinum (%) Palladium (%) 96.9 102.8 95.5 100.9 95.7 103.1 96.8 103.6 95.9 103.7 Average Recovery Rate (%) 96.2 102.8

Claims (17)

A waste catalyst discharged from an exhaust gas purifier; And a solvent containing fluoric acid, nitric acid, and hydrochloric acid, and a telerium solution, into a sealed container, and firstly heating the mixture using microwaves;
Adding a solvent including sodium chloride, hydrochloric acid and telerium solution to the first mixed solution to form a second mixed solution;
Injecting the second mixed solution into a hermetically sealed container and performing secondary heating using microwaves;
Adding a solvent containing hydrochloric acid to the second mixed solution to form a third mixed solution; And
And quantifying the amount of the metal contained in the third mixed solution. 2. A method for quantifying a metal included in a waste catalyst of an exhaust gas purifying apparatus, comprising:
The method according to claim 1,
Wherein the spent catalyst discharged from the exhaust gas purifying apparatus comprises at least one metal compound selected from the group consisting of platinum and palladium.
The method according to claim 1,
Wherein the first heating using the microwave is carried out at 80 to 100 atm to 180 to 210 占 폚 for 100 to 150 minutes.
The method according to claim 1,
Wherein said mixed acid is included in a spent catalyst of an exhaust gas purifying apparatus in which hydrofluoric acid, nitric acid, and hydrochloric acid are mixed at a molar ratio of 1: 0.1 to 2: 10 to 20.
The method according to claim 1,
Wherein the reaction molar ratio of the hydrofluoric acid solution to the telarium solution in the first mixed solution is in the range of 15: 1 to 2: 1.
The method according to claim 1,
Wherein a solvent containing 30 to 100 ml of mixed acid and telerium solution is reacted with 1 g of waste catalyst in the first mixed solution.
The method according to claim 1,
Wherein the second heating using the microwave is carried out at 80 to 100 atm to 200 to 220 deg. C for 100 to 150 minutes.
The method according to claim 1,
Wherein the sodium chloride is reacted with 1 g to 1 g of the spent catalyst in the step of producing the second mixed solution.
The method according to claim 1,
Wherein the molar ratio of hydrochloric acid to telarium solution in the step of preparing the second mixed solution is in the range of 2: 1 to 1: 2.
The method according to claim 1,
Wherein a solvent containing 1 to 30 ml of hydrochloric acid and a telerium solution is reacted with 1 g of the waste catalyst in the step of producing the second mixed solution.
The method according to claim 1,
The first or second heating step using the microwave may further include a step of raising the temperature of the first mixed solution and the second mixed solution to 150 ° C to 250 ° C respectively, .
The method according to claim 1,
Wherein the microwave has an output of 700 to 1500 watts in the primary or secondary heating step.
The method according to claim 1,
Further comprising the step of cooling at a temperature of -30 DEG C to 70 DEG C for 30 to 70 minutes after the primary or secondary heating using the microwave.
14. The method of claim 13,
Wherein the cooling step comprises cooling at a temperature of 40 to 60 占 폚 for 10 to 30 minutes and cooling at -10 to -30 占 폚 for 20 to 40 minutes so that the amount of metal contained in the waste catalyst of the exhaust gas purification apparatus Way.
The method according to claim 1,
Further comprising nitric acid in the step of producing the third mixed solution.
The method according to claim 1,
Wherein the step of quantifying the amount of the metal contained in the third mixed solution comprises the atomic emission spectroscopy method.
The method according to claim 1,
Wherein the step of quantifying the amount of the metal contained in the third mixed solution includes an inductively coupled plasma atomic emission spectrometer (ICP-AES).