KR20220034672A - Method for recovery of platinum group metal - Google Patents

Abstract

The present invention relates to a method for recovering platinum group metals. The method for recovering platinum group metals comprises: a rolling step of rolling platinum melting furnace lining scrap containing platinum group metals; a leachate preparation step of preparing a leachate containing the platinum group metals by inputting and dissolving the platinum melting furnace lining scrap containing the platinum group metals rolled in the rolling step into a reaction tank filled with aqua regia; a leachate concentration step of concentrating the leachate prepared in the leachate preparation step; and a platinum group metal recovery step of, after putting the concentrate prepared in the leachate concentration step into a mixing tank and injecting an oxidizing gas to heat the concentrate to a temperature of 80 to 90 ℃, preparing a mixed solution having an acidity of pH 7 to 8 by injecting an oxidizing gas into the concentrate and mixing the same with a separating solution, cooling the mixed solution by injecting an oxidizing gas into the mixed tank, and the obtaining the platinum group metals by filtering the cooled mixed solution. The method for recovering platinum group metals through the above exhibits an effect of recovering the platinum group metals such as platinum, rhodium, and palladium contained in the platinum melting furnace lining scrap with excellent yield.

Description

Method for recovering platinum group metals {METHOD FOR RECOVERY OF PLATINUM GROUP METAL}

The present invention relates to a method for recovering platinum group metals, and more particularly, to a method for recovering platinum group metals, such as platinum, rhodium and palladium, contained in industrial wastes with excellent yield.

In general, platinum group metals are widely used as high-quality useful materials in precious metals and electronic industries, and are widely used in fields such as aviation materials, petrochemicals and automobile catalysts because they are physically and chemically stable even at high temperatures, and recently, in the development of the IT industry. As the demand for high-purity platinum is rapidly increasing, the platinum group market is continuously increasing.

However, the amount of industrial wastes discharged after using platinum such as scraps for electronic devices, waste catalysts for petrochemicals, scraps for automobiles and blast furnace linings for glass industry is also increasing in proportion to the market growth, so the technology that can recycle platinum group metals This is a situation that is desperately needed.

In particular, due to the limitations of advanced recycling technologies, a large amount of platinum group metal waste currently discharged in Korea is being recycled and re-imported. In line with the rapid growth of the platinum-related market, it is urgent to develop advanced platinum group recycling technology as well as create added value through revitalization of related new industries.

It is known that the platinum group metal has a low oxidation potential, so leaching is very difficult, and the leaching rate is slow and the time required for leaching occupies more than 70% of the total process time. Precipitation and crystallization methods, solvent extraction methods, oxidative distillation methods, and electrolytic refining methods are known, and the traditional separation and purification process of platinum group metals is a process that requires repeated dissolution, conditioning, and precipitation processes several times. However, the solvent extraction method is currently mostly used due to its high inefficiency, such as the complexity of operation and labor intensiveness.

Existing solvent extraction methods for separating and purifying platinum group metals are based on the species of dissolved ion complexes, redox potential, ligand exchange rate, extractant reaction, extraction rate, etc. It shows separation efficiency, and it is possible to achieve high purity of separated platinum, and it has advantages such as high productivity, flexibility and diversity of the process, and continuity of operation and process control.

In particular, in the aqua regia leaching process using aqua regia, a method of leaching platinum and palladium by leaching platinum group metals contained in the leaching solution using aqua regia is used. In the case of industrial waste containing rhodium, the recovery rate of platinum decreases in proportion to the content of rhodium, so it is not suitable for the treatment of scrap, etc. discharged from the glass industry. There was a downside to that.

Accordingly, there is a need for a method for recovering a platinum group metal that is suitable for the treatment of scraps discharged from the glass industry, etc. because the recovery rates of both rhodium and platinum are excellent.

Korean Patent Registration No. 10-1114491 (02.02.2012) Korean Patent Registration No. 10-1712763 (2017.02.27)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for recovering platinum group metals in which platinum group metals such as platinum, rhodium and palladium contained in platinum blast furnace lining scrap are recovered in excellent yield.

An object of the present invention is a rolling step of rolling the platinum blast furnace lining scrap containing the platinum group metal, the platinum blast furnace lining scrap including the platinum group metal rolled through the rolling step is put into a reactor filled with aqua regia and dissolved to contain the platinum group metal a leachate preparation step of preparing a leachate for After heating to a temperature of It is achieved by providing a method for recovering a platinum group metal, characterized in that it comprises a platinum group recovery step of filtering the mixed solution to obtain a platinum group metal solution.

According to a preferred feature of the present invention, the rolling step is to be made by rolling the platinum furnace lining scrap to a thickness of 0.15 to 0.3 millimeters.

According to a more preferred feature of the present invention, the aqua regia shall consist of 10 to 20M.

According to a more preferred feature of the present invention, the aqua regia shall consist of 100 parts by weight of hydrochloric acid and 30 to 35 parts by weight of nitric acid.

According to an even more preferred feature of the present invention, the separation solution is sodium hydroxide, sodium nitrite, sodium nitrate, sodium sulfate, sodium sulfide, ammonium hydroxide, ammonium chloride, oxalic acid, ammonium oxalate, calcium hydroxide, potassium hydroxide, diethylamine and α- It shall consist of at least one selected from the group consisting of benzoinoxime.

According to an even more preferred feature of the present invention, the separation liquid is sodium hydroxide, and the mass concentration is assumed to be 25 to 35%.

According to an even more preferred feature of the present invention, the oxidizing gas is made of chlorine gas, and is injected in an amount of 0.05 to 0.15 L/min.

The method for recovering a platinum group metal according to the present invention exhibits an excellent effect of recovering platinum group metals such as platinum, rhodium and palladium contained in the lining scrap of a platinum furnace with an excellent yield.

1 is a flowchart illustrating a method for recovering a platinum group metal according to the present invention.

Hereinafter, a preferred embodiment of the present invention and the physical properties of each component will be described in detail, which is intended to describe in detail enough that a person of ordinary skill in the art to which the present invention pertains can easily carry out the invention, This does not mean that the technical spirit and scope of the present invention is limited.

A method for recovering a platinum group metal according to the present invention is a rolling step (S101) of rolling a platinum blast furnace lining scrap containing a platinum group metal, and a regia of the platinum blast furnace lining scrap including the rolled platinum group metal through the rolling step (S101). A leachate preparation step (S103) of preparing a leachate containing a platinum group metal by introducing and dissolving it in a reactor filled with it; S105) is put into the mixing tank, and an oxidizing gas is injected to heat the concentrate to a temperature of 80 to 90 ° C. Then, an oxidizing gas is injected into the concentrate and the separated solution is mixed to have an acidity of pH 7 to 8 It consists of a platinum group recovery step (S107) of preparing a mixed solution, injecting an oxidizing gas into the mixing tank to cool the mixed solution, and filtering the cooled mixed solution to obtain a platinum group metal solution.

The rolling step (S101) is a step of rolling a platinum furnace lining scrap containing a platinum group metal, and is made by rolling the platinum furnace lining scrap to a thickness of 0.15 to 0.3 millimeters, in the case of platinum, rolling to a thickness of 0.3 mm In the case of a mixture of platinum and rhodium (mass concentration of 10%), it is preferably rolled to a thickness of 0.2 mm, and in the case of a mixture of platinum and rhodium (mass concentration of 20%), it is rolled to a thickness of 0.15 mm desirable.

In the case of industrial waste rolled to the same thickness as described above, not only part of the platinum group metal is separated during the rolling process, but also the specific surface area is increased, so that the leaching rate of the platinum group metal is improved.

In the step of preparing the leachate (S103), the platinum blast furnace lining scrap including the platinum group metal rolled through the rolling step (S101) is put into a reactor filled with aqua regia and dissolved to prepare a leachate containing the platinum group metal.

The aqua regia is preferably used in a concentration of 10 to 20M, and 100 parts by weight of hydrochloric acid and 30 to 35 parts by weight of nitric acid.

In addition, the platinum blast furnace lining scrap containing the platinum group metal can be used as a raw material for recovering the platinum group metal, such as waste electronic device scrap, petrochemical waste catalyst, car waste catalyst, waste scrap discharged from glass factories, etc. and, preferably, waste scrap including platinum and rhodium discharged from a glass factory can be used as a raw material.

The step of concentrating the leachate (S105) is a step of concentrating the leachate prepared in the step of preparing the leachate (S103), and the process of preparing the leachate with an improved concentration by concentrating the leachate prepared in the step of preparing the leach (S103). Although various concentration methods can be used to prepare a leachate having an improved concentration, preferably, a concentrated leachate can be prepared using a heat concentration method in which the leachate is heated and concentrated, and the platinum group metal is contained in the range of 500,000 to 800,000 mg/L It is preferable to prepare a concentrated leachate containing a concentration of

In the platinum group recovery step (S107), the concentrated solution prepared in the leachate concentration step (S105) is put into a mixing tank and an oxidizing gas is injected to heat the concentrated solution to a temperature of 80 to 90° C., and then an oxidizing gas is injected into the concentrated solution and mixing the separated solution to prepare a mixed solution having an acidity of 7 to 8, injecting an oxidizing gas into the mixing tank to cool the mixed solution, and filtering the cooled mixed solution to obtain a platinum group metal solution.

More preferably, in the platinum group recovery step (S107), the concentrated solution and the basic solution prepared in the leachate concentration step (S105) are mixed in a mixing tank to prepare a mixed solution, and the prepared mixed solution is filtered to obtain a platinum group metal solution It consists of a process for obtaining, and the separated solution may be mixed so that platinum group metals such as platinum, rhodium, palladium, etc. can be purified and recovered from the concentrate containing the platinum group metal.

The separation solution is a group consisting of sodium hydroxide, sodium nitrite, sodium nitrate, sodium sulfate, sodium sulfide, ammonium hydroxide, ammonium chloride, oxalic acid, ammonium oxalate, calcium hydroxide, potassium hydroxide, diethylamine and α-benzoinoxime It is preferable that it consists of one or more selected from, and it is most preferable that it consists of sodium hydroxide having a mass concentration of 25 to 35%.

In addition, the separation solution can be mixed until the acidity of the concentrate is pH 7 to 8 to achieve excellent separation efficiency for platinum (Pt) among platinum group metals. There is a problem in that the content of platinum group metals increases, and when mixed at a pH exceeding 8, there is a problem in that the content of platinum in the concentrated leachate decreases.

In particular, the reaction conditions may be adjusted so that only platinum among the platinum group metals contained in the concentrate can be separated with high purity. An oxidizing gas such as argon or helium is injected into the mixing tank to heat the concentrated leachate at a temperature of 80 to 90 ℃ After heating with a furnace, the basic solution is mixed in a state in which an oxidizing gas such as chlorine gas is directly injected into the mixed solution in the mixing tank to prepare a mixed solution having an acidity of 7 to 8, and then the oxidizing gas is added to the mixing tank The mixed solution is cooled by injection, and the cooled mixed solution is filtered to obtain a platinum solution containing platinum with high purity.

In this case, chlorine gas can be used as the oxidizing gas, and the chlorine gas is more environmentally friendly because the gas discharged after reacting the electrolyte containing hydrochloric acid with industrial waste in the leachate manufacturing step can be collected and reused. process can be performed.

When chlorine gas is injected into the mixing tank as described above, the reaction activity of chlorine gas is greatly increased through heating, and platinum group metal chlorides are formed, which further improves the solubility of platinum group metals contained in the concentrated leachate, thereby further increasing separation efficiency. It is possible to achieve the effect of further improving the purity of platinum, which has high solubility compared to rhodium or palladium.

In addition, to effectively reduce the content of platinum group metals such as rhodium through filtration, and to obtain high-purity platinum, the step of adding a coagulant to the prepared mixed solution may be additionally performed, so that rhodium is coagulated in the coagulant And, it can be configured to obtain a platinum solution containing only high-purity platinum by filtering the mixed solution to which the coagulant is added, and as such a coagulant, various conventional polymeric flocculants capable of coagulating rhodium can be used, 2 Polymers such as -ethylhexanoate (2-ethylhexanoate) can be cited as representative examples.

Hereinafter, the method for recovering the platinum group metal according to the present invention and the recovery rate of the platinum group metal recovered through the recovery method will be described with reference to examples.

<Example 1>

The scrap containing platinum was rolled to a thickness of 0.3 mm, and 1 L of aqua regia (100 parts by weight of hydrochloric acid and 33 parts by weight of nitric acid) was prepared. was measured, and a titanium rod was manufactured and combined with the platinum-containing scrap. At room temperature, 86 g of a platinum-containing scrap specimen (2×5 cm, thickness: 0.3T) was supplied to aqua regia and stirred. Platinum was leached from the scrap.

<Example 2>

The same procedure as in Example 1, except that the palladium-containing scrap was rolled to a thickness of 0.2 mm instead of platinum, and palladium was leached from the palladium-containing scrap.

<Example 3>

The same procedure as in Example 1 was performed, except that rhodium-containing scrap was rolled to a thickness of 0.15 mm instead of platinum, and rhodium was leached from the rhodium-containing scrap.

The leaching rates of the platinum group metals made in Examples 1 to 3 were measured and shown in Table 1 below.

{However, the leaching rate was calculated through concentration analysis by aliquoting the leachate at 1, 3, 6, and 12 hours, respectively.}

<Table 1>

As shown in Table 1, it can be seen that the leaching solutions prepared in Examples 1 to 3 of the present invention have excellent leaching rates of platinum group metals.

<Example 4>

After heating the leachate prepared in Example 1 and concentrating to a concentration of 650,000 mg/L, the concentrate was put into a mixing tank, and an oxidizing gas was injected to heat the concentrate to a temperature of 85° C., and then an oxidizing gas was added to the concentrate. A mixed solution having an acidity of pH 7 to 8 is prepared by injecting and mixing the separation solution (trium hydroxide having a mass concentration of 30%), and an oxidizing gas (chlorine gas) is injected into the mixing tank to cool the mixed solution, and cooled The mixed solution was filtered to recover platinum.

<Example 5>

After heating the leachate prepared in Example 2 and concentrating to a concentration of 650,000 mg/L, the concentrate was added to a mixing tank, and an oxidizing gas was injected to heat the concentrate to a temperature of 85° C., and then an oxidizing gas was added to the concentrate. A mixed solution having an acidity of pH 7 to 8 is prepared by injecting and mixing the separation solution (trium hydroxide having a mass concentration of 30%), and an oxidizing gas (chlorine gas) is injected into the mixing tank to cool the mixed solution, and cooled The mixed solution was filtered to recover palladium.

<Example 6>

After heating the leachate prepared in Example 3 and concentrating to a concentration of 650,000 mg/L, the concentrate was added to a mixing tank, and oxidizing gas was injected to heat the concentrate to a temperature of 85° C., and then an oxidizing gas was added to the concentrate. A mixed solution having an acidity of pH 7 to 8 is prepared by injecting and mixing the separation solution (trium hydroxide having a mass concentration of 30%), and an oxidizing gas (chlorine gas) is injected into the mixing tank to cool the mixed solution, and cooled The mixed solution was filtered to recover rhodium.

The recovery rates of the platinum group metals recovered through Examples 4 to 6 were measured and shown in Table 2 below. As measuring equipment, the Glow Discharge Mass Spectrometer (GD-MS; device code AI74) owned by the Research Equipment Operation Department of Ohchang Headquarters (Korea Institute of Basic Science) and the inductively coupled plasma spectrometer (manufacturer (model); Thermo Fisher Scientific Korea ( The recovery rate was measured using iCAP 6000 SERIES)).

<Table 2>

As shown in Table 2, it can be seen that the recovery method of Examples 4 to 6 of the present invention has a very excellent recovery rate of platinum group metal exceeding 99%.

Accordingly, the method for recovering platinum group metals according to the present invention recovers platinum group metals such as platinum, rhodium and palladium contained in the platinum furnace lining scrap with excellent yield.

S101; rolling stage
S103; Leachate preparation step
S105 ; Leachate Concentration Step
S107; Platinum family recovery stage

Claims (7)

A rolling step of rolling a platinum furnace lining scrap containing a platinum group metal;
a leachate manufacturing step of preparing a leachate containing the platinum group metal by putting the platinum blast furnace lining scrap including the platinum group metal rolled through the rolling step into a reactor filled with aqua regia and dissolving it;
a leachate concentration step of concentrating the leachate prepared through the leachate preparation step; and
The concentrate prepared through the leachate concentration step is put into a mixing tank, and an oxidizing gas is injected to heat the concentrate to a temperature of 80 to 90 ° C. Then, an oxidizing gas is injected into the concentrate, and the separated solution is mixed so that the acidity is pH 7 to 7 A platinum group recovery step of preparing a mixed solution of 8, injecting an oxidizing gas into the mixing tank to cool the mixed solution, and filtering the cooled mixed solution to obtain a platinum group metal solution; method.
The method according to claim 1,
The rolling step is a method for recovering a platinum group metal, characterized in that made by rolling the lining scrap of the platinum furnace to a thickness of 0.15 to 0.3 millimeters.
The method according to claim 1,
The aqua regia is a method for recovering a platinum group metal, characterized in that it consists of 10 to 20M.
4. The method according to claim 3,
The aqua regia comprises 100 parts by weight of hydrochloric acid and 30 to 35 parts by weight of nitric acid.
According to claim 1,
The separation solution is at least one selected from the group consisting of sodium hydroxide, sodium nitrite, sodium nitrate, sodium sulfate, sodium sulfide, ammonium hydroxide, ammonium chloride, oxalic acid, ammonium oxalate, calcium hydroxide, potassium hydroxide, diethylamine and α-benzoinoxime A method for recovering platinum group metals, comprising:
6. The method of claim 5,
The separation solution is sodium hydroxide, and a method for recovering a platinum group metal, characterized in that the mass concentration is 25 to 35%.
The method according to claim 1,
The oxidizing gas is made of chlorine gas, the platinum group metal recovery method, characterized in that injected in an amount of 0.05 to 0.15 L / min.

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