Method for recovering iridium from deliquescent iridium chloride
By adding surfactants, pH regulators, and strong alkali to the tide chloride, it has successfully improved the recovery and efficiency of the recovery rate and process of water, and solved the existing technology. Recycling difficulties.
Patent Information
- Application Number
- CN202411469402.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-01-24
AI Technical Summary
The prior art is difficult to efficiently recover iridium from deliques iridium chloride, and traditional methods have problems with complex devices and processes, safety and efficiency.
By dispersing deliquesced iridium chloride in a co-surfactant, adding a pH adjuster and a strong base, iridate is generated, and is heated in an oil bath until the strong base is completely dissolved, followed by a hydrothermal reaction, and finally in an inert atmosphere Medium calcination to obtain pure phase metal elemental iridium.
This method can efficiently recover iridium, with a comprehensive recovery rate of 86%-93%. The process is simple, safe, and has low production cost. It has significant economic benefits and extensive market promotion value.
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Figure CN119351768A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the technical field of precious metal recovery, and in particular to a method for recovering iridium from deliquesced iridium chloride. Background Art
[0002] Due to its good catalytic activity, corrosion resistance and oxidation resistance at high temperatures, Ir is widely used in high-temperature corrosion protection, catalytic oxidation and electroluminescence. Considering the high value, scarcity and low recovery rate of secondary resources containing Ir, it is very important to improve the ability to purify Ir-containing materials. Ir has a face-centered cubic structure, a coordination number of 12, a melting point of 2450°C, an atomic number of 77, and an outer electron arrangement of 5d76s2, belonging to the VIII group of the sixth period. Due to its excellent high-temperature corrosion resistance and redox catalytic activity, it has been widely used in high-temperature corrosion resistance, hydrogenation catalysts, electrocatalysis, electroluminescence and other fields. Ir is one of the rarest elements on earth, and its concentration in the earth's crust is only 0.000003ppm. Usually, iridium is a by-product of the secondary mining process, which is used to refine platinum and palladium. The Ir content produced by PGM production varies from deposit to deposit, with an average of about 1%. The current annual production of iridium is about 5.5-7.7 tons, mainly produced in South Africa (production of more than 85%) and Zimbabwe.
[0003] According to the Platinum Group Metals Survey reported by Johnson Matthee, the global demand for Ir will reach 8.0 tons in 2022, of which the electrochemical industry will demand 3.1 tons, the electronics industry will demand 2.0 tons, the chemical industry will demand 0.9 tons, and other industries will demand 2.0 tons. In this regard, secondary resource Ir mainly comes from mainstream products in the above four industries, such as oxygen evolution anodes in the electrochemical industry, Ir crucibles in the electronics industry, iridium acetate and Ir alloy spark plugs in the chemical industry, etc. With the proposal and promotion of the global net zero policy, iridium is mainly used in electrochemical industries such as water electrolysis and fuel cells. With the rapid development and industrial application of the electrochemical industry, the demand for iridium is also growing steadily. At present, only 40%-50% of the end-of-life recycling (EOL) has been realized in industrial applications. The contradiction between supply and demand, the high value of Ir itself and the low yield have prompted researchers to focus on the recycling of Ir.
[0004] In the process of recovering and purifying iridium, it is difficult to dissolve due to its excellent antioxidant and corrosion resistance; in addition, the iridium ions in the solution are affected by factors such as temperature, acidity, and oxidation potential, and often undergo valence changes or reactions such as hydration and hydroxylation, which bring certain difficulties to purification. The incineration method is to mix the waste liquid containing iridium catalysts used in the pharmaceutical and chemical industries with carbon for incineration to remove organic components in the waste liquid. This method may cause the volatilization of organic iridium compounds or the formation of iridium oxide, which will make subsequent dissolution difficult. Aqua regia can be used to oxidize and remove organic matter in the solution, but this method is not suitable for all organic matter, and it is easy to decompose incompletely, requiring hydrolysis for further separation. Therefore, it is very important to attach importance to the recovery of iridium and develop effective purification and refining technologies. Summary of the invention
[0005] In view of this, the embodiment of the present application provides a method for recovering iridium from deliquesced iridium chloride. The method has wide applicability, high recovery rate of platinum group metals, simple and easy method, safety, low production cost, green energy saving and environmental protection, etc., has significant economic benefits and wide market promotion value, and can effectively overcome the defects of the above-mentioned prior art.
[0006] The present application embodiment provides a method for recovering iridium from deliquesced iridium chloride, comprising the following steps:
[0007] The deliquesced iridium chloride is dispersed in a co-surfactant to obtain an iridium chloride solution; a pH adjuster is first added to adjust the pH value of the iridium chloride solution; a strong base is then added to generate iridate, and the mixture is heated in an oil bath until the strong base is completely dissolved to obtain a mixture solution; the mixture solution is placed in a reactor for hydrothermal reaction to obtain a product, which is washed several times with an organic solvent, and the product is dried and calcined in an inert atmosphere to obtain a pure phase of metallic elemental iridium.
[0008] The recovery method of the present application embodiment is different from the traditional alkali melting method in that the present application method uses a strong base to react with iridium chloride under the action of co-surfactant hexanol and acetic acid to generate intermediate IrO3 - ; The alkali fusion method refers to the process of mixing a substance with a strong alkaline substance such as sodium hydroxide and melting it at a high temperature to decompose the sample and extract the target element; the method of the present application is to react a strong base with iridium chloride in a closed reactor.
[0009] In some embodiments, which may include the above embodiments, the oil bath temperature is 100-120°C.
[0010] In some embodiments that may include the above embodiments, the hydrothermal reaction temperature is 180-200° C., and the hydrothermal reaction time is 30-48 hours.
[0011] In some embodiments that may include the above embodiments, the calcination temperature is 500-700° C., the calcination time is 2 hours, the heating rate is 5° C. / min; and the inert atmosphere is argon.
[0012] In some embodiments that may include the above embodiments, the drying is performed by vacuum drying, and the vacuum drying temperature is 60°C.
[0013] In some embodiments that may include the above-mentioned embodiments, the dosage ratio of the deliquescent iridium chloride: co-surfactant: pH adjuster: strong base is (10mM~50mM):(15ml~30ml):(30ml~60ml):(24mM~48mM), wherein the strong base is potassium hydroxide or sodium hydroxide.
[0014] In some embodiments that may include the above embodiments, the pH adjuster is acetic acid, and the pH value of the iridium chloride solution is adjusted to 2-5.
[0015] In some embodiments, which may include the above embodiments, the co-surfactant is hexanol.
[0016] In some embodiments, which may include the above embodiments, the organic solvent is ethanol.
[0017] Compared with the prior art, the embodiments of the present application have the following beneficial effects:
[0018] The method for recovering iridium in the embodiment of the present application does not require complicated equipment and processes to extract iridium from deliquesced iridium chloride, which is safer and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0020] Figure 1 This is a process flow chart of an embodiment of the present application;
[0021] Figure 2 The XRD pattern of pure phase elemental iridium was obtained in Example 2 of the present application. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0023] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.
[0024] In the following examples, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.
[0025] All raw materials were of analytical grade.
[0026] Example 1
[0027] like Figure 1 As shown, the method for recovering iridium from deliquescent iridium chloride in the present embodiment comprises the following steps:
[0028] (1) Disperse 25 mM deliquescent iridium chloride in 30 ml of ethanol;
[0029] (2) adding 60 ml of acetic acid to adjust the pH to 4, adding 48 mM potassium hydroxide and heating in an oil bath at 120° C. until the potassium hydroxide is completely dissolved to obtain a mixture solution;
[0030] (3) placing the mixture solution in a reactor and performing a hydrothermal reaction at 200° C. for 48 hours to obtain a product, washing the product with ethanol for 5 times, and drying the product under vacuum at 60° C.;
[0031] (4) The dried reactant was heated to 700° C. at a heating rate of 5° C. / min and calcined at 700° C. for 2 hours under an argon atmosphere to obtain pure metal iridium. The comprehensive recovery rate of iridium in this embodiment is 86%.
[0032] Example 2
[0033] like Figure 1 As shown, the method for recovering iridium from deliquescent iridium chloride in the present embodiment comprises the following steps:
[0034] (1) Disperse 25 mM deliquescent iridium chloride in 15 ml of ethanol;
[0035] (2) adding 30 ml of acetic acid to adjust the pH value to 4, adding 24 mM potassium hydroxide and heating in an oil bath at 120° C. until the potassium hydroxide is completely dissolved to obtain a mixture solution;
[0036] (3) placing the mixture solution in a reactor for hydrothermal reaction at 200° C. for 48 hours to obtain a product, washing it with ethanol for 5 to 6 times, and drying it in a vacuum at 60° C.;
[0037] (4) The dried reactant was heated to 700°C at a rate of 5°C / min and calcined at 700°C for 2 hours under an argon atmosphere to obtain pure metal iridium. The XRD pattern of pure metal iridium is as follows: Figure 2 As shown, the comprehensive recovery rate of iridium in this embodiment is 93%.
[0038] Example 3
[0039] like Figure 1 As shown, the method for recovering iridium from deliquescent iridium chloride in the present embodiment comprises the following steps:
[0040] (1) Disperse 50 mM deliquescent iridium chloride in 15 ml of ethanol;
[0041] (2) adding 30 ml of acetic acid to adjust the pH value to 4, adding 24 mM potassium hydroxide and heating in an oil bath at 120° C. until the potassium hydroxide is completely dissolved to obtain a mixture solution;
[0042] (3) placing the mixture solution in a reactor for hydrothermal reaction at 200° C. for 48 hours to obtain a product, washing it with ethanol for 5 to 6 times, and drying it in a vacuum at 60° C.;
[0043] (4) The dried reactant was heated to 700° C. at a heating rate of 5° C. / min and calcined at 700° C. for 2 hours under an argon atmosphere to obtain pure metal iridium. The comprehensive recovery rate of iridium in this embodiment is 90%.
[0044] Example 4
[0045] The method for recovering iridium from deliquesced iridium chloride in this embodiment can refer to Example 2, except that: the oil bath temperature is 100°C.
[0046] Example 5
[0047] The method for recovering iridium from deliquesced iridium chloride in this embodiment can refer to Example 2, except that: the hydrothermal reaction temperature is 180°C.
[0048] Example 6
[0049] The method for recovering iridium from deliquesced iridium chloride in this embodiment can refer to Example 2, except that: the calcination temperature is 500°C.
[0050] Example 7
[0051] The method for recovering iridium from deliquesced iridium chloride in this embodiment can refer to Example 2, except that: the strong base is sodium hydroxide.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for recovering iridium from deliquescent iridium chloride, characterized in that, The following steps are involved: The deliquesced iridium chloride is dispersed in a co-surfactant to obtain an iridium chloride solution; a pH adjuster is first added to adjust the pH value of the iridium chloride solution; a strong base is then added to generate iridate, and the mixture is heated in an oil bath until the strong base is completely dissolved to obtain a mixture solution; the mixture solution is placed in a reactor for hydrothermal reaction to obtain a product, which is washed several times with an organic solvent, and the product is dried and calcined in an inert atmosphere to obtain a pure phase of metallic elemental iridium.
2. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that The oil bath temperature is 100-120°C.
3. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The hydrothermal reaction temperature is 180-200° C., and the hydrothermal reaction time is 30-48 hours.
4. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The calcination temperature is 500-700° C., the calcination time is 2 hours, and the heating rate is 5° C. / min; the inert atmosphere is argon.
5. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The drying is performed by vacuum drying, and the vacuum drying temperature is 60°C.
6. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The dosage ratio of the deliquescent iridium chloride: co-surfactant: pH regulator: strong base is (10mM-50mM):(15ml-30ml):(30ml-60ml):(24mM-48mM), wherein the strong base is potassium hydroxide or sodium hydroxide.
7. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The pH regulator is acetic acid, and the pH value of the iridium chloride solution is adjusted to 2-5.
8. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The co-surfactant is hexanol.
9. The method for recovering iridium from deliquescent iridium chloride according to claim 1, characterized in that, The organic solvent is ethanol.