Recovery method of catalyst containing platinum, silver, chromium, vanadium, molybdenum and aluminum

Abstract

The invention discloses a recovery method of a catalyst containing platinum, silver, chromium, vanadium, molybdenum and aluminum, which comprises the following steps: uniformly mixing a waste catalyst, caustic alkali and iron powder, reacting at high temperature, cooling to obtain a melt, dissolving the melt, and filtering to obtain a first filter residue and a first filtrate; dissolving the first filter residue with nitric acid, and filtering to obtain platinum-containing waste filter residue and second filtrate; adding a sodium chloride solution into the second filtrate, and filtering to obtain silver chloride filter residues and third filtrate which contains chromic nitrate; adding a barium chloride solution into the third filtrate, reacting at room temperature, and filtering to obtain barium chromate solid filter residues and fourth filtrate; adjusting the pH value of the first filtrate to 7-8 by using an acid, reacting at room temperature, and filtering to obtain activated aluminum oxide filter residues and a fifth filtrate; adding ammonium chloride into the fifth filtrate, reacting at room temperature, and filtering to obtain ammonium vanadate filter residues and sixth filtrate; and adjusting the pH value of the sixth filtrate to be less than 1 by using sulfuric acid, reacting at room temperature, and filtering to obtain molybdic acid filter residues and a seventh filtrate.

Description

Technical Field

[0001] This invention relates to the field of metal recycling technology, and more particularly to a method for recovering catalysts containing platinum, silver, chromium, vanadium, molybdenum and aluminum. Background Technology

[0002] In the petrochemical industry, catalysts using alumina as a carrier and metals such as platinum, silver, chromium, vanadium, and molybdenum as active components are widely used in reforming and isomerization units. Currently, hundreds of thousands of tons of these catalysts are replaced annually. Direct disposal would not only result in a massive waste of precious metals and aluminum resources but also place a serious burden on the environment as they are classified as hazardous waste. While existing pyrometallurgical recovery processes can treat these spent catalysts, they suffer from high energy consumption and costs, and also generate large amounts of aluminum-containing slag, increasing the difficulty of subsequent treatment.

[0003] To address the aforementioned issues, the comprehensive utilization of spent catalysts containing metals such as platinum, silver, chromium, vanadium, and molybdenum, using alumina as a carrier, is still in its initial stages. Therefore, developing a novel, efficient, energy-saving, and environmentally friendly recycling process to achieve the efficient separation and comprehensive utilization of valuable metal components is of significant practical importance and application value. Summary of the Invention

[0004] The present invention aims to solve the problem of how to recover catalysts with alumina as a carrier and different contents of platinum, silver, chromium, vanadium, molybdenum and aluminum as active materials, and provides a method for recovering catalysts containing platinum, silver, chromium, vanadium, molybdenum and aluminum.

[0005] To achieve the above-mentioned technical objectives, the technical solution provided by this invention is as follows: A method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum includes the following steps: Step 1: Mix the waste catalyst, caustic alkali, and iron powder evenly, then melt and react them at high temperature, and cool to obtain a melt; Step 2: Dissolve the melt and filter to obtain the first filter residue and the first filtrate; Step 3: Dissolve the first filter residue from Step 2 with nitric acid and filter to obtain the filter residue containing platinum waste and the second filtrate; Step 4: Add sodium chloride solution to the second filtrate from Step 3, filter to obtain silver chloride residue and a third filtrate, the third filtrate containing chromium nitrate; Step 5: Add barium chloride solution to the second filtrate from Step 4, react at room temperature, and then filter to obtain barium chromate solid residue and the fourth filtrate; Step 6: Adjust the pH of the first filtrate from Step 2 to 7-8 with acid, react at room temperature, and then filter to obtain activated alumina filter residue and the fifth filtrate; Step 7: Add ammonium chloride to the fifth filtrate, react at room temperature, and then filter to obtain ammonium vanadate residue and the sixth filtrate; Step 8: Adjust the pH of the sixth filtrate to less than 1 with sulfuric acid, react at room temperature, and then filter to obtain molybdic acid residue and the seventh filtrate.

[0006] Furthermore, in step 1, the waste catalyst, caustic alkali, and iron powder are in a weight ratio of 1:2-3:0.05-0.2; The temperature is 550-700℃, and the reaction time is 3-4 hours, during which the waste catalyst needs to be ground into powder.

[0007] Sodium hydroxide can be used as the caustic alkali.

[0008] Furthermore, in step 2, the amount of water used for dissolution is 1:15-20 by weight of waste catalyst to water.

[0009] Furthermore, in step 3, the first filter residue is dissolved in nitric acid at a weight ratio of 1:2-5 for 5-6 hours; the filter residue containing platinum waste is recovered using a method for purifying platinum.

[0010] One method for purifying platinum is to use existing technology, dissolve the filter residue of platinum-containing waste in aqua regia, filter it, add ammonium chloride solid to the filtrate to obtain ammonium chloroplatinate precipitate, and calcine it at 800℃ to obtain sponge platinum.

[0011] Furthermore, in step 4, the amount of sodium chloride added is the first filter residue: sodium chloride 1:0.5-2 by weight, and the reaction time is 3-4 hours.

[0012] Specifically, sodium chloride is dissolved in water at a concentration of approximately 10-30 g / 100 ml; silver chloride filter residue is purified into silver using the silver purification process.

[0013] Among them, the silver purification process of silver chloride filter residue is an existing technology. The crude silver chloride is dissolved in ammonia water and filtered. Then, the pH is adjusted to between 7 and 8 with hydrochloric acid to obtain refined silver chloride, which is then reduced with hydrazine hydrate to obtain sponge silver.

[0014] Furthermore, in step 5, the fourth filtrate is treated as wastewater; the amount of 10% barium chloride solution added is based on a weight ratio of 1:0.5-2 for the first filter residue to the barium chloride solution.

[0015] Furthermore, in step 6, the reaction time is 3-4 hours, and sulfuric acid can be used as the acid.

[0016] Furthermore, in step 7, the amount of ammonium chloride added is 1:0.2-2 by weight of old catalyst:ammonium chloride, and the reaction time is 4-5 hours.

[0017] Specifically, ammonium chloride is dissolved in water at a concentration of 10-50g / 100ml.

[0018] Furthermore, in step 8, the reaction time is 4-5 hours.

[0019] The waste liquid is adsorbed with activated carbon and then filtered. The filtrate is treated as wastewater, and the filter residue is collected.

[0020] The present invention has the following beneficial effects: This invention successfully separates and recovers platinum, silver, chromium, aluminum, vanadium, and molybdenum from spent catalysts. Chromium, vanadium, molybdenum, and aluminum are amphoteric oxides that can react with caustic alkalis such as sodium hydroxide to produce soluble hexavalent chromates, vanadates, molybdates, and aluminates (the specific salts depend on the caustic alkali). Among these, hexavalent chromates are stable and difficult to separate from vanadates, molybdates, and aluminates. Therefore, by adding reducing iron powder during the alkali fusion reaction, chromium is converted into soluble trivalent sodium chromate. Sodium chromate hydrolyzes under alkaline conditions to form insoluble trivalent chromium oxide compounds, which then precipitate out. The filtrate after water leaching and filtration contains vanadates, molybdates, and aluminates, while the filter residue contains platinum oxide, silver oxide, trivalent chromium oxide, and other elemental metals. This process achieves the coarse separation of platinum, silver, and chromium from aluminum, vanadium, and molybdenum. The filter residue is dissolved by nitric acid, which has oxidizing properties. Silver and chromium enter the solution as silver nitrate and sodium hexavalent chromate, while platinum remains in the filter residue, thus achieving crude separation of chromium, silver, and platinum. By adding sodium chloride to synthesize insoluble silver chloride with silver nitrate, crude separation of silver and chromium is achieved. Barium chloride is added to the filtrate to synthesize insoluble barium hexavalent chromate compound, thus achieving crude separation and purification of chromium and other impurities.

[0021] The filtrate from water leaching is adjusted to a pH of 7-8, causing aluminate hydrolysis into insoluble activated alumina, thus achieving the coarse separation of aluminum, vanadium, and molybdenum, as well as the purification of aluminum. Ammonium chloride is added to the filtrate to react with vanadate, yielding slightly water-soluble ammonium vanadate, achieving the coarse separation of vanadium and molybdenum, and the purification of vanadium. Adjusting the pH of the filtrate to strongly acidic conditions yields slightly soluble molybdic acid, which precipitates from the solution, achieving the purification of molybdenum. Residual vanadium and molybdenum in the filtrate are adsorbed by activated carbon, and the filtrate is treated as wastewater. Attached Figure Description

[0022] Figure 1 This is a process flow diagram of the present invention; Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] The old catalyst used in the examples contained 0.1-0.2% platinum oxide, 5-10% silver oxide, 0.05-2% chromium oxide, 2-10% vanadium oxide, 2-10% molybdenum oxide, 75-90% aluminum oxide, and other residual impurities <1%.

[0026] like Figure 1 The diagram shown is a process flow chart of the present invention.

[0027] Example 1 One ton of old catalyst was weighed, ground into powder, and then 2.5 tons of sodium hydroxide and 100 kg of iron powder were weighed and mixed together. The mixture was placed in an iron tray and melted in an industrial muffle furnace at 600°C for 3 hours. After cooling, the melt was removed. 18 tons of water were added to dissolve the melt, and the mixture was allowed to stand and filtered. The filtrate was reserved for later use. The filter residue was dried to obtain 220 kg of solid. 450 kg of nitric acid was weighed and dissolved by stirring at room temperature for 6 hours, then filtered. Platinum was recovered from the filter residue using a common method for platinum recovery. 250 kg of sodium chloride was added to the filtrate, and after precipitation, the mixture was filtered. Silver was recovered from the filter residue using a common method for silver recovery. 120 kg of a 10% barium chloride solution was added to the filtrate, and the mixture was reacted at room temperature for 6 hours, then filtered. The filter residue was barium chromate, and the filtrate was discharged.

[0028] The solution to be used was adjusted to pH 7-8 with acid, reacted at room temperature for 4 hours, filtered, and the residue was alumina. 500 kg of ammonium chloride was added to the filtrate, reacted at room temperature for 5 hours, and then filtered again, the residue being ammonium vanadate. The filtrate was then adjusted to pH less than 1 with sulfuric acid, reacted at room temperature for 4 hours, and then filtered again, the residue being molybdic acid. The filtrate was then adsorbed with activated carbon and filtered again. After centralized treatment with the activated carbon, the filtrate was discharged.

[0029] Example 2 Five tons of old catalyst were weighed, ground into powder, and then 12 tons of sodium hydroxide and 500 kg of iron powder were weighed, mixed, and placed in an iron tray. The mixture was then melted in an industrial muffle furnace at 600°C for 4 hours. After cooling, the melt was removed and dissolved in 80 tons of water. The mixture was then allowed to stand and filtered, and the filtrate was reserved for use. After drying the filter residue, 850 kg of solid was obtained. The filter residue was reacted with 1.8 tons of nitric acid at room temperature for 6 hours. After standing and filtering, the filter residue was a platinum concentrate, which was recovered and purified using conventional methods. A solution containing 1.5 tons of sodium chloride was added to the filtrate, and the mixture was allowed to stand and filter. The resulting filter residue was silver chloride, which was recovered and purified using the same process as for silver purification. Finally, 800 kg of 10% barium chloride solution was added to the filtrate, and the mixture was reacted at room temperature for 6 hours before filtration. The resulting filter residue was solid barium chromate, and the filtrate was treated as wastewater.

[0030] The filtrate to be used was adjusted to pH 7-8 with acid, reacted at room temperature for 4 hours, and then filtered. The filter residue was activated alumina. One ton of ammonium chloride was added to the filtrate and reacted at room temperature for 5 hours. After standing and filtration, the filter residue was ammonium vanadate. The filtrate was adjusted to pH < 1 with sulfuric acid, reacted at room temperature for 4 hours, and then filtered. The filter residue was molybdic acid. After adsorption with activated carbon, the filtrate was treated as wastewater, and the activated carbon was centrally treated.

[0031] Example 3 Ten tons of old catalyst were weighed, ground into powder, and mixed with 25 tons of sodium hydroxide and 500 kg of iron powder. The mixture was placed in an iron tray and melted in an industrial muffle furnace at 650°C for 4 hours. After cooling, the melt was removed and dissolved in 160 tons of water. The mixture was then allowed to stand and filtered, and the filtrate was reserved for use. After drying the filter residue, 1.5 tons of solid were obtained. The solid was stirred in 3.5 tons of nitric acid at room temperature for 6 hours. After standing and filtering, the filter residue was a platinum-rich material, which was purified using common methods. One ton of sodium chloride was added to the filtrate, and after standing and filtering, the filter residue was silver chloride, which was recovered and purified using conventional methods. An aqueous solution of 850 kg of barium chloride (10% concentration) was added to the filtrate, and after reacting at room temperature for 7 hours, the mixture was allowed to stand and filtered. The filter residue was barium chromate solid, and the filtrate was treated as wastewater.

[0032] The filtrate from the first step was adjusted to a pH of 7-8 with acid, reacted at room temperature for 4 hours, and then filtered. The filter residue was activated alumina. A solution containing 500 kg of ammonium chloride was added to the filtrate, reacted at room temperature for 5 hours, allowed to stand, and then filtered. The filter residue was ammonium vanadate. The filtrate was then adjusted to a pH < 1 with sulfuric acid, reacted at room temperature for 4 hours, and then filtered. The filter residue was molybdic acid. The filtrate was then adsorbed with activated carbon and filtered again. The filter residue was collected, and the filtrate was treated as wastewater.

[0033] Comparative Example 1 Iron powder is not used during alkali fusion.

[0034] Comparative Example 2 During chromium precipitation, the weight ratio is 1:<0.5 for the first filter residue to barium dichloride.

[0035] Comparative Example 3 During the hydrolysis of aluminates, the pH is between 1-6 or 9-12.

[0036] Comparative Example 4 During vanadate precipitation, the weight ratio of old catalyst to ammonium chloride is 1:<0.2.

[0037] Comparative Example 5 pH > 1 during molybdenum precipitation.

[0038] Comparative Example 6: Waste liquid was not adsorbed using activated carbon.

[0039] The relevant test results of the examples and comparative examples are shown in Table 1.

[0040] Table 1: Relevant test results of examples and comparative examples Alkali-melted filter residue Filter residue (after nitrate hydrolysis) Waste liquid after silver and chromium immersion Waste liquid after aluminum precipitation Waste liquid containing vanadium and molybdenum precipitation Waste liquid after activated carbon adsorption Final waste Example 1 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum <10ppm Vanadium <200ppm, Molybdenum <200ppm Vanadium <0.5ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Example 2 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum <10ppm Vanadium <200ppm, Molybdenum <200ppm Vanadium <0.5ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Example 3 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum <10ppm Vanadium <200ppm, Molybdenum <200ppm Vanadium <0.5ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Comparative Example 1 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.01ppm Aluminum <10ppm, Chromium >5% Vanadium <200ppm, Molybdenum <200ppm, Chromium >5% Vanadium <0.5ppm, Molybdenum <0.5ppm, Chromium >5% Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, chromium oxide >2%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Comparative Example 2 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium >200ppm Aluminum <10ppm Vanadium <200ppm, Molybdenum <200ppm Vanadium <0.5ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide >500ppm, chromium oxide >1%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Comparative Example 3 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum >500ppm Vanadium <200ppm, Molybdenum <200ppm Vanadium <0.5ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide <0.01%, molybdenum oxide <0.01%, aluminum oxide >2%. Comparative Example 4 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum >500ppm Vanadium >1000ppm, Molybdenum <200ppm Vanadium >100ppm, Molybdenum <0.5ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide >1%, molybdenum oxide <0.01%, aluminum oxide <0.1%. Comparative Example 5 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum >500ppm Vanadium <200ppm, Molybdenum >500ppm Vanadium <0.5ppm, Molybdenum >50ppm Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide <0.01%, molybdenum oxide >0.5%, aluminum oxide <0.1%. Comparative Example 6 Alumina <0.5%, Vanadium oxide <0.01%, Molybdenum oxide <0.01% Platinum oxide >15% Silver <5ppm, Chromium <0.5ppm Aluminum <10ppm Vanadium <200ppm, Molybdenum <200ppm / Platinum oxide <0.01%, silver oxide <0.01%, chromium oxide <0.005%, vanadium oxide >1%, molybdenum oxide >0.5%, aluminum oxide <0.1%. The product results of the example are shown in Table 2.

[0041] Table 2 Product Results of Examples

[0042] As can be seen from the results in Tables 1 and 2, the method according to the embodiments of this application can effectively and crudely separate platinum, silver, chromium, molybdenum, vanadium, and aluminum, and the purity of the obtained product meets the standard for reuse. In Comparative Example 1, no reducing agent iron powder was used during alkali fusion, and chromium entered the solution but was not hydrolyzed. This is because the stability of hexavalent chromium is greater than that of trivalent chromium, and the resulting hexavalent chromate cannot be hydrolyzed, so chromium cannot be removed in subsequent processes. In addition, when precipitating chromium, an appropriate amount of barium chloride is more effective in precipitating chromium. Aluminate hydrolyzes alumina most completely under neutral conditions. In Comparative Example 3, under slightly acidic or slightly alkaline conditions, the residual aluminum ions in the solution are high. Ammonium vanadate is slightly soluble in water, and adding an appropriate amount of ammonium chloride can reduce the solubility. In Comparative Example 4, the amount of ammonium chloride is lower than that in the examples, and the amount of precipitated vanadium is lower than that in the examples. Molybdate will precipitate as molybdate under acidic conditions. The higher the acidity, the higher the yield of molybdate to molybdate. In Comparative Example 5, when the acidity is >1, the precipitation of molybdenum is less complete than in the examples. Since ammonium vanadate and molybdate are only slightly soluble in water, the residual content in the wastewater does not meet the waste disposal requirements. Adsorption with activated carbon effectively reduces the residual vanadium and molybdenum in the wastewater.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0044] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum, characterized in that, Includes the following steps: Step 1: Mix the waste catalyst, caustic alkali, and iron powder evenly, then melt and react them at high temperature, and cool to obtain a melt; Step 2: Dissolve the melt and filter to obtain the first filter residue and the first filtrate; Step 3: Dissolve the first filter residue from Step 2 with nitric acid and filter to obtain platinum-containing waste filter residue and second filtrate; Step 4: Add sodium chloride solution to the second filtrate from Step 3, filter to obtain silver chloride residue and a third filtrate, the third filtrate containing chromium nitrate; Step 5: Add barium chloride solution to the third filtrate from Step 4, react at room temperature, and then filter to obtain barium chromate solid residue and the fourth filtrate; Step 6: Adjust the pH of the first filtrate from Step 2 to 7-8 with acid, react at room temperature, and then filter to obtain activated alumina filter residue and the fifth filtrate; Step 7: Add ammonium chloride to the fifth filtrate, react at room temperature, and then filter to obtain ammonium vanadate residue and the sixth filtrate; Step 8: Adjust the pH of the sixth filtrate to less than 1 with sulfuric acid, react at room temperature, and then filter to obtain molybdic acid residue and the seventh filtrate.

2. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 1, the waste catalyst, caustic alkali, and iron powder are in a weight ratio of 1:2-3:0.05-0.2; The temperature is 550-700℃, and the reaction time is 3-4 hours.

3. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 2, the amount of water used for dissolution is 1:15-20 by weight of waste catalyst to water.

4. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 3, the first filter residue is dissolved in nitric acid at a weight ratio of 1:2-5 for 5-6 hours.

5. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 4, the amount of sodium chloride added is based on a weight ratio of 1:0.5-2 (first filter residue: sodium chloride), and the reaction is carried out for 3-4 hours.

6. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 5, the fourth filtrate is treated as wastewater; the 10% barium chloride solution is added at a weight ratio of 1:0.5-2 based on the first filter residue to barium chloride solution.

7. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 6, the reaction time is 3-4 hours.

8. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 7, the amount of ammonium chloride added is 1:0.2-2 by weight of old catalyst:ammonium chloride, and the reaction time is 4-5 hours.

9. The method for recovering a catalyst containing platinum, silver, chromium, vanadium, molybdenum, and aluminum according to claim 1, characterized in that, In step 8, the reaction time is 4-5 hours.

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