A method for efficiently recovering palladium from a waste palladium / resin catalyst

Abstract

The present application relates to the technical field of palladium recovery, and particularly discloses a method for efficiently recovering palladium from waste palladium / resin catalysts, which can achieve the following effects through the steps of oxygen-rich roasting, vacuum roasting, and synergistic oxidative leaching: under the condition of oxygen enrichment, the decomposition and combustion of high-molecular organic matter are accelerated, and the decomposition rate of the resin carrier is improved; under conventional roasting conditions, the resin decomposition rate is 70-80% in 1-2 hours, and after oxygen is blown in, the organic matter decomposition rate is increased to 85-95%, which is conducive to the subsequent leaching of palladium; meanwhile, the required roasting temperature is reduced, and efficient decomposition of organic matter can be achieved at 500-650 DEG C; through vacuum roasting, palladium oxide is reduced under high-temperature conditions, thereby shortening the reduction process and improving the efficiency; through the synergistic leaching of hydrochloric acid+hydrogen peroxide+ozone, the leaching rate is improved; through the ozone oxidation of divalent palladium in the solution, the system is more environmentally friendly than nitric acid and chlorine systems, and pollution is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to a palladium recovery method, in particular to a method for efficiently recovering palladium from waste palladium / resin catalysts, and belongs to the technical field of palladium recovery. BACKGROUND

[0002] Palladium is one of the rare platinum group metals, and its use amount is increasing year by year, and it has become the largest platinum group metal in the world. According to industry statistics, the demand for palladium catalysts in China accounts for more than 90% of the total demand for palladium. In the petroleum chemical industry, palladium catalysts can be applied to the production of organic chemical raw materials such as selective hydrogenation, acetaldehyde, and vinyl acetate. The use of palladium catalysts can reduce pollution caused by the production process, maximize energy saving and consumption reduction requirements, and create good conditions for the development of new reaction routes and new processes in the petroleum chemical industry. However, the palladium mineral resources in China are limited and far cannot meet the development needs of various industries. Among them, the waste palladium / resin catalyst used in the petrochemical and pharmaceutical industries as an important secondary resource containing palladium has an annual domestic output of nearly one hundred tons, with a Pd content of 1.5-2%. Recycling and reusing it is of great significance to solve the contradiction between supply and demand of palladium resources in China.

[0003] At present, the recovery of palladium / resin waste catalysts in industry mainly adopts the process route of calcination-reduction-leaching-purification.

[0004] The resin carrier is decomposed by calcination to generate carbon dioxide and water vapor, which can avoid the insufficient contact between palladium and hydrochloric acid in the subsequent leaching, thereby affecting the leaching reaction speed and efficiency. If the calcination temperature is too low and the calcination time is too short, the carrier decomposition is not complete, and if the calcination temperature is too high and the calcination time is too long, palladium may be seriously oxidized, which is not conducive to the leaching of palladium.

[0005] During the calcination process, part of the palladium is oxidized to form palladium oxide, which has very strong acid and alkali resistance, and even aqua regia cannot dissolve it. Therefore, the material after calcination needs to be reduced before leaching to reduce palladium oxide to palladium, so as to improve the leaching rate of palladium in the subsequent acid leaching process. The most common method currently used is to use hydrazine hydrate as a reducing agent to reduce palladium oxide, but hydrazine hydrate is expensive, which increases the production cost. After reduction, a large amount of water must be used to wash the reducing agent, otherwise the amount of hydrochloric acid and oxidizing agent used in the subsequent leaching process will be greatly increased. During the washing of hydrazine hydrate, on the one hand, a large amount of wastewater will be generated, and with the increasing environmental protection requirements, a large amount of wastewater will increase the treatment cost of enterprises; on the other hand, the palladium metal attached to the surface of the waste material will also be lost with the washing water, resulting in a decrease in the metal recovery rate. At the same time, the hydrazine hydrate washing process is time-consuming, which reduces the production efficiency and increases the production cost.

[0006] After the catalyst is calcined, it is leached by wet method. The leaching process mainly includes aqua regia dissolution method and chlorination dissolution method, so that palladium enters the solution in ionic form.

[0007] The aqua regia dissolution method is one of the common methods for recycling the spent palladium-containing resin catalyst at present, because the process equipment is simple, the cost is low, and the operating conditions are easy to control. However, the aqua regia dissolution of palladium produces a large amount of nitrogen oxides, which seriously pollutes the environment, and the treatment cost of waste water and waste gas of enterprises is high.

[0008] The chlorination dissolution method is stable and reliable, has high leaching rate, and has high economic benefits. However, chlorine gas used in the chlorination method has strong toxicity, and the equipment must have certain airtightness. At the same time, the system has strong acidity and strong oxidizing property, which requires high equipment and large investment cost.

[0009] The purification of palladium generally adopts ammonium chloride precipitation method. Tetravalent palladium reacts with ammonium chloride to form (NH4)2PdCl6 precipitate, so as to separate palladium from impurities. Divalent palladium cannot form precipitate with ammonium chloride, so it cannot realize the separation of palladium and impurities. However, tetravalent palladium is unstable and can easily change into divalent, so it is necessary to add an oxidizing agent to the solution before adding ammonium chloride, so as to oxidize divalent palladium to tetravalent, so as to ensure the effect of ammonium chloride precipitation of palladium. The commonly used oxidizing agent is nitric acid and chlorine gas. Using nitric acid for oxidation produces nitrogen-containing waste gas and waste water, which is difficult to treat. Using chlorine gas for oxidation has poor operating environment.

[0010] Patent CN201810562151.4 discloses a method for recovering palladium from a spent catalyst containing palladium. The palladium is recovered by a full wet process, and a large amount of organic waste liquid is generated in the elution process, which is difficult to treat subsequently.

[0011] Patent CN202010905956.1 discloses a method for recovering palladium from a spent palladium resin catalyst. The method mainly adopts a fire capture process, which includes the following steps: (1) uniformly mixing the spent palladium resin catalyst with a binder and a metal iron oxide in a certain proportion, and performing vacuum carbonization; (2) placing the carbonization product in a high-temperature furnace to melt and reduce the metal iron oxide to metal iron and capture palladium, so as to obtain a molten metal palladium-iron alloy product, and obtain a palladium-iron alloy powder by atomization treatment; (3) selectively dissolving iron by adding sulfuric acid, and after the dissolution reaction is completed, filtering and washing to obtain a palladium enrichment product and an iron-containing filtrate; (4) dissolving the palladium enrichment product with ferric chloride solution, filtering to obtain a palladium chloride solution, and reducing to obtain a crude palladium powder by adding hydrazine hydrate; the method recovers palladium by a fire capture process, introduces a large amount of additives, and the melting temperature is as high as 1400℃, so the treatment cost is relatively high. After obtaining the alloy enrichment product, the processes of powder spraying, iron dissolution, and liquid preparation need to be performed again, so the process is long and the efficiency is low. SUMMARY

[0012] The present application provides a method for efficiently recovering palladium from waste palladium / resin catalysts.

[0013] The object of the present application can be achieved by the following technical solutions.

[0014] A method for efficiently recovering palladium from waste palladium / resin catalysts, comprising the following steps:

[0015] Step 1: Take a predetermined amount of waste palladium / resin catalyst and perform oxygen-rich roasting.

[0016] Step 2: After step 1 is completed, nitrogen is introduced, and then the temperature is raised, and the roasting is continued, and the predetermined vacuum degree in the furnace is maintained; after the roasting is completed, the temperature is lowered, and nitrogen is continuously introduced for protection during the cooling process.

[0017] Step 3: Take the palladium / resin catalyst after roasting in step 2, add hydrochloric acid and water to start heating, add hydrogen peroxide after reaching the predetermined temperature, continue the reaction by introducing ozone after reacting for a predetermined time, and then perform solid-liquid separation to obtain a filtrate and a residue.

[0018] Step 4: The filtrate obtained in step 3 is subjected to ozone oxidation, and then ammonium chloride is added to precipitate palladium to obtain ammonium chloropalladate.

[0019] Step 5: The ammonium chloropalladate is subjected to ammonia treatment with ammonia water, acidification with hydrochloric acid, and finally reduction with hydrazine hydrate to obtain qualified palladium powder.

[0020] Optionally, the oxygen-rich roasting conditions in step 1 are that the oxygen concentration in the furnace is 25-50%, the roasting temperature is 500-650 DEG C, and the roasting time is 1-2 h.

[0021] Optionally, the chemical reaction formula during the oxygen-rich roasting process is C8H8+10O2=8CO2+4H2O, C3H4O2+3O2=3CO2+2H2O.

[0022] Optionally, the vacuum roasting temperature in step 2 is 750-850 DEG C, the roasting time is 2-3 h, and the vacuum degree is 100-1000 Pa; during the nitrogen protection process, the nitrogen is stopped until the temperature is reduced to below 100 DEG C.

[0023] Optionally, the temperature of hydrogen peroxide addition in step 3 is 80-95 DEG C, the dropping time is 1-2 h, the dropping speed is 20 ml / h, and the ozone addition time is 1-2 h.

[0024] Optionally, the catalyst:water:hydrochloric acid:hydrogen peroxide:ozone in step 3 is taken in a ratio of 100 g:(200-300) ml:(50-100) ml:(20-40) ml:(10-20) ml.

[0025] Optionally, the temperature is room temperature, and the duration is 20-40 min.

[0026] Advantages of the present application:

[0027] The present application can achieve the following effects by carrying out oxygen-enriched roasting: 1. Under the same time condition, the resin decomposition rate is improved. The oxygen-enriched condition accelerates the decomposition and combustion of high-molecular organic matter, and improves the decomposition rate of the resin carrier. Under the conventional roasting condition, the resin decomposition rate is 70-80% in 1-2 h, and the organic matter decomposition rate is improved to 85-95% after oxygen is introduced, which is beneficial to the subsequent leaching of palladium. 2. The required roasting temperature is reduced. Efficient decomposition of organic matter can be achieved at 500-650℃.

[0028] After the oxygen-enriched roasting is completed, the oxygen supply is stopped, and nitrogen is introduced to keep the system free of oxygen. Then the temperature is increased to 750-850℃, and the vacuum degree is maintained at 100-1000 Pa, at which the palladium oxide decomposes palladium and oxygen. The decomposition temperature of the palladium oxide under normal pressure and oxygen condition is 900-950℃. By supplementing nitrogen and maintaining a certain vacuum degree, the oxygen partial pressure is effectively reduced, and the decomposition of the palladium oxide is promoted. The temperature at which the palladium oxide is completely decomposed is reduced to 750-850℃, and the energy consumption is reduced. Then nitrogen protection is carried out during the cooling process to avoid the oxidation of palladium again.

[0029] The leaching process adopts hydrogen peroxide + ozone synergistic oxidation leaching. First, hydrochloric acid + hydrogen peroxide is used for leaching, and then ozone is continuously supplied for a period of time for oxidation leaching, which can improve the palladium leaching rate to more than 99%.

[0030] The leaching solution is then used for palladium precipitation by ammonium chloride. Since divalent palladium is unstable, the solution is oxidized before palladium precipitation in the traditional process, and the oxidizing agent is generally nitric acid or chlorine. In the present process, ozone with stronger oxidizing property than chlorine is used for oxidation, and the effect of palladium precipitation is significantly improved. The palladium concentration in the tail liquid after palladium precipitation is less than 0.01 g / L, the palladium precipitation rate is greater than 99.9%, and the recovery rate is more than 99.6%. At the same time, no waste gas is generated in the ozone oxidation process, which reduces the pollution of waste gas and waste water. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to facilitate the understanding of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0032] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] Please refer to Figure 1 As shown in the figure, a method for efficiently recovering palladium from waste palladium / resin catalyst, the method comprises the following steps:

[0035] Step 1: Take a predetermined amount of waste palladium / resin catalyst and perform oxygen-rich roasting;

[0036] Step 2: After step 1 is completed, nitrogen is blown in, and then the temperature is raised to continue roasting, and a predetermined vacuum degree in the furnace is maintained; after roasting is completed, the temperature is lowered, and nitrogen protection is continued during the cooling process;

[0037] Step 3: Take the palladium / resin catalyst after roasting in step 2, add hydrochloric acid and water to start heating, add hydrogen peroxide after reaching the predetermined temperature, continue the reaction by blowing ozone after reacting for a predetermined time, and then perform solid-liquid separation to obtain filtrate and filter residue;

[0038] Step 4: The filtrate obtained in step 3 is subjected to ozone oxidation, and then ammonium chloride is added to precipitate palladium to obtain ammonium chloropalladate. This method makes the concentration of palladium in the tail liquid less than 0.01 g / L.

[0039] Step 5: Ammonium chloropalladate is ammoniated with ammonia water, acidified with hydrochloric acid, purified, and finally reduced with hydrazine hydrate to obtain qualified palladium powder.

[0040] Specifically, the oxygen-rich roasting conditions in step 1 are that the oxygen concentration in the furnace is 25-50%, the roasting temperature is 500-650℃, and the roasting time is 1-2h.

[0041] Specifically, the chemical reaction formula during the oxygen-rich roasting process is C8H8+10O2=8CO2+4H2O, C3H4O2+3O2=3CO2+2H2O.

[0042] Specifically, the vacuum roasting temperature in step 2 is 750-850℃, the roasting time is 2-3h, and the vacuum degree is 100-1000Pa; during the nitrogen protection process, nitrogen is stopped until the temperature is reduced to below 100℃.

[0043] Specifically, the temperature when hydrogen peroxide is added in step 3 is 80-95℃, the dropping time is 1-2h, the dropping speed is 20ml / h, and the ozone addition time is 1-2h.

[0044] Specifically, the amount of catalyst: water: hydrochloric acid: hydrogen peroxide: ozone in step 3 is 100g: (200-300) ml: (50-100) ml: (20-40) ml: (10-20) ml.

[0045] Specifically, during the oxidation process of the filtrate in step 4, the ozone is bubbled at a rate of 15-30% of the liquid volume, the temperature is room temperature, and the duration is 20-40 minutes.

[0046] Palladium / resin catalyst is a catalyst in which palladium is supported on a resin carrier, commonly used in hydrogenation, dehydrogenation and coupling reactions. The resin carrier is usually a high molecular polymer (such as polystyrene, polyacrylic acid, etc.), which has high chemical stability and controllable surface functional groups. Polystyrene decomposes in air conditions, and oxygen participates in the reaction, leading to oxidative decomposition and combustion, which can be decomposed into carbon dioxide, water and other small molecule gases at about 600°C. The reaction is as follows: C8H8+10O2=8CO2+4H2O. The decomposition behavior of polyacrylic acid in air conditions is closely related to its molecular structure, molecular weight and heating conditions. Since polyacrylic acid contains carboxyl groups (-COOH), it will undergo thermal oxidative degradation and combustion during heating. Generally, it can be decomposed into carbon dioxide, water and other small molecule gases at about 600°C. The reaction is as follows: C3H4O2+3O2=3CO2+2H2O. However, the resin carrier generally uses high molecular weight or cross-linked polystyrene or polyacrylic acid, which contains additives or stabilizers, and cannot be completely decomposed at 600°C. The actual decomposition rate is 70-80%. Due to incomplete decomposition of the resin, a small amount of palladium remains in the resin structure, making it difficult to leach out, and the leaching rate is generally 90-95%. The present application performs oxygen-enriched roasting, which supplements a certain amount of oxygen during roasting to maintain the oxygen content in the roasting atmosphere between 25-50% (conventional roasting does not supplement additional oxygen, and the oxygen content is basically the same as that in the atmosphere, about 21%). This accelerates the decomposition and combustion of high molecular organic matter, improves the decomposition rate of the resin carrier, and the decomposition rate of the carrier can reach 85-95%, the palladium leaching rate reaches more than 99.8%, which is 5-10% higher than the conventional roasting-leaching process.

[0047] Part of the palladium is oxidized to form palladium oxide during the roasting process. The traditional process is to reduce the material after roasting with hydrazine hydrate or other reducing agents to reduce the palladium oxide to palladium, so that it can be leached. The wet reduction process has high cost (the reduction cost of each kg of material is 2-3 yuan), low production efficiency (at least 24 hours are needed for the whole process of reduction, filtration and washing), and is easy to cause loss of palladium (0.5-1% of palladium is taken away by the solution in the reduction process). For the material after roasting, the invention again uses vacuum roasting to decompose the palladium oxide in the material into palladium and oxygen under the condition of no oxygen and vacuum. The material after roasting can be directly leached without the reduction process. The equipment used is a vacuum induction melting furnace. The same equipment is used to directly use vacuum roasting after oxygen-rich roasting, which realizes efficient use of heat energy, shortens the production process, improves production efficiency and reduces metal loss. At the same time, due to the oxygen-free and vacuum environment, the decomposition temperature of the palladium oxide is reduced. The method of the invention decomposes the palladium oxide into palladium, reduces the cost, improves the production efficiency and reduces the loss of palladium. The treatment cost of each kg of material is 1-1.5 yuan, the whole process takes 6-7 hours, and there is no loss of palladium.

[0048] The traditional acid leaching process uses a strong oxidizing aqua regia system and a chlorine gas system, which has a poor operating environment and serious corrosion of equipment. The invention uses a "hydrogen peroxide + ozone synergistic oxidation" leaching system, which has low corrosion of equipment, a friendly operating environment and good leaching effect, and can ensure that the leaching rate of palladium reaches more than 99.8%.

[0049] The obtained palladium-containing solution is first oxidized to oxidize the divalent palladium in the solution to tetravalent, and then ammonium chloride is added to obtain ammonium chloropalladate, which can be purified. The traditional ammonium chloride palladium precipitation process uses nitric acid or chlorine gas for oxidation, which has a poor operating environment and difficult treatment of nitrogen-containing waste gas and waste water. The invention uses ozone for oxidation, and the oxygen generated after ozone oxidation has no pollution to the environment.

[0050] In summary, the invention uses one-stage oxygen-rich roasting to improve the resin decomposition rate, two-stage vacuum roasting to reduce the decomposition temperature of the palladium oxide, and eliminates the traditional material reduction process to improve the production efficiency. The leaching process innovatively proposes a "hydrogen peroxide + ozone" synergistic oxidation leaching system to synergistically leach palladium and improve the leaching rate of palladium. The ammonium chloride palladium precipitation process uses ozone oxidation to reduce the difficulty of waste liquid and waste gas treatment. The combination of various processes realizes short-flow continuous and efficient operation, overcomes the problems of low carrier decomposition rate in the traditional roasting process, large water washing amount in the reduction process, large loss of palladium metal, low working efficiency, and serious environmental pollution in the leaching process and purification process, improves the palladium recovery rate and improves the production efficiency.

[0051] In the embodiment of the present application, the contents of palladium, resin and other metals in the waste palladium / resin catalyst are 1.5%, 97.5% and 1% respectively. The following embodiments are used to illustrate the details.

[0052] Embodiment 1 provides a method for recovering palladium from waste palladium / resin catalyst, which comprises the following steps:

[0053] Step 1: 1000g of waste palladium / resin catalyst is placed in a calcination furnace, oxygen is blown in, the oxygen concentration in the furnace is maintained at 25%, the temperature is raised to 650℃, and the temperature is maintained for 1h.

[0054] Step 2: After step 1 is completed, nitrogen is blown in to exhaust all air, then the temperature is raised, and the vacuum degree in the furnace is maintained at 100pa. After the temperature reaches 750℃, the temperature is maintained for 2h. Then the temperature is lowered, and nitrogen is continuously blown in during the temperature lowering process.

[0055] Step 3: 150g of the product obtained in step 2 is placed in a beaker, 100ml of hydrochloric acid and 300ml of water are added, and the temperature is raised. After the temperature reaches 80℃, 40ml of hydrogen peroxide is added dropwise within 1h for leaching, and then 30ml of ozone is blown in within 2h for continuous leaching. After the reaction is completed, the solid-liquid separation is performed to obtain 600ml of filtrate. The leaching residue is 130g, the content of palladium is 0.02%, and the leaching rate of palladium is 99.82%.

[0056] Step 4: The filtrate is oxidized by blowing in 90ml of ozone within 20min at room temperature. Then ammonium chloride is used to precipitate palladium, and the palladium concentration in the tail liquid is detected to be 0.005g / L.

[0057] Step 5: The ammonium chloropalladate is then purified until 14.96g of qualified palladium powder is obtained, and the recovery rate of palladium is 99.73%.

[0058] Embodiment 2 comprises the following steps, Step 1: 1000g of waste palladium / resin catalyst is placed in a calcination furnace, oxygen is blown in, the oxygen concentration in the furnace is maintained at 35%, the temperature is raised to 550℃, and the temperature is maintained for 1.5h.

[0059] Step 2: After step 1 is completed, nitrogen is blown in to exhaust all air, then the temperature is raised, and the vacuum degree in the furnace is maintained at 500pa. After the temperature reaches 800℃, the temperature is maintained for 2.5h. Then the temperature is lowered, and nitrogen is continuously blown in during the temperature lowering process.

[0060] Step 3: Put all the product of step 2, 100 g, into a beaker, add 100 ml of hydrochloric acid and 300 ml of water to start heating, when the temperature reaches 90 °C, add 40 ml of hydrogen peroxide dropwise for leaching in 1.5 h, then continue leaching by blowing 20 ml of ozone in 1.5 h. After the reaction is completed, solid-liquid separation is performed to obtain a filtrate of 580 ml. The leaching residue is 85 g, containing 0.03% of palladium, and the palladium leaching rate is 99.83%.

[0061] Step 4: The filtrate is oxidized by blowing 87 ml of ozone in 30 min at room temperature. Then ammonium chloride is added to precipitate palladium, and the palladium concentration in the tail liquid is detected to be 0.007 g / L.

[0062] Step 5: The ammonium chloropalladate is then purified until the qualified palladium powder of 14.97 g is obtained, and the palladium recovery rate is 99.80%.

[0063] Example 3 includes the following steps, Step 1: Put 1000 g of waste palladium / resin catalyst into a calcination furnace, blow oxygen to maintain the oxygen concentration in the furnace at 50%, and heat to 500 °C for 2 h.

[0064] Step 2: After step 1 is completed, nitrogen is blown to empty all the oxygen, then heating is started, and the vacuum degree in the furnace is maintained at 1000 pa. When the temperature reaches 850 °C, keep the temperature for 3 h. Then start to cool down, and continue to blow nitrogen during the cooling process.

[0065] Step 3: Put all the product of step 2, 50 g, into a beaker, add 50 ml of hydrochloric acid and 150 ml of water to start heating, when the temperature reaches 95 °C, add 20 ml of hydrogen peroxide dropwise for leaching in 1 h. Then continue leaching by blowing 5 ml of ozone in 1 h. After the reaction is completed, solid-liquid separation is performed to obtain a filtrate of 350 ml. The leaching residue is 43 g, containing 0.07% of palladium, and the palladium leaching rate is 99.80%.

[0066] Step 4: The filtrate is oxidized by blowing 52.5 ml of ozone in 40 min at room temperature. Then ammonium chloride is added to precipitate palladium, and the palladium concentration in the tail liquid is detected to be 0.006 g / L.

[0067] Step 5: The ammonium chloropalladate is then purified until the qualified palladium powder of 14.96 g is obtained, and the palladium recovery rate is 99.67%.

[0068] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments described. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to best explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application and get the best results from the application. The application is only limited by the claims and their full scope and equivalents.

Claims

1. A method for efficiently recovering palladium from a spent palladium / resin catalyst, characterized by, The method comprises the following steps: Step 1: take a predetermined amount of waste palladium / resin catalyst, and perform oxygen-rich roasting; Step 2: after step 1 is completed, nitrogen is blown in, and then the temperature is raised, and the roasting is continued, and a predetermined vacuum degree in the furnace is maintained, the vacuum roasting temperature is 750-850 DEG C, the roasting time is 2-3h, and the vacuum degree is 100-1000Pa; after roasting, the temperature is lowered, and nitrogen is continuously blown in during the cooling process; Step 3: take the palladium / resin catalyst roasted in step 2, add hydrochloric acid and water, and start heating, then add hydrogen peroxide after reaching the preset temperature, continue to react by blowing in ozone after reacting for a preset time, and then solid-liquid separation is performed to obtain a filtrate and a filter residue; Step 4: the filtrate obtained in step 3 is subjected to ozone oxidation, and then ammonium chloride is added to precipitate palladium to obtain ammonium chloropalladate; Step 5: ammonium chloropalladate is subjected to ammonia treatment with ammonia water, acidification with hydrochloric acid, purification, and finally reduction with hydrazine hydrate to obtain qualified palladium powder.

2. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, The oxygen-rich roasting condition in step 1 is that the oxygen concentration in the furnace is 25-50%, the roasting temperature is 500-650 DEG C, and the roasting time is 1-2h.

3. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, The chemical reaction formula in the oxygen-rich roasting process is C8H8+10O2=8CO2+4H2O, and C3H4O2+3O2=3CO2+2H2O.

4. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, In the nitrogen protection process of step 2, the nitrogen blowing is stopped until the temperature is reduced to below 100 DEG C.

5. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, In step 3, the temperature when hydrogen peroxide is added is 80-95 DEG C, the dropping time is 1-2h, the dropping speed is 20ml / h, and the ozone adding time is 1-2h.

6. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, In step 3, the catalyst:water:hydrochloric acid:hydrogen peroxide:ozone is taken in a ratio of 100g:(200-300)ml:(50-100)ml:(20-40)ml:(10-20)ml.

7. The method for efficiently recovering palladium from waste palladium / resin catalyst according to claim 1, characterized by, In the oxidation process of the filtrate in step 4, the ozone blowing amount is 15-30% of the liquid volume, the temperature is room temperature, and the duration is 20-40min.

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