A wet recovery method and device for oil-containing waste catalyst

Abstract

The present invention discloses a wet recovery method for oil-containing waste catalysts, comprising: a. filling the electrochemical reaction chamber between the cathode and the rotating anode of a rotating electrode electrolytic cell with oil-containing waste catalyst particles; b. circulating an acidic electrolyte into the electrolytic cell; c. inputting a voltage into the electrolytic cell, and electrochemically separating the oil-containing waste catalyst to obtain oil compounds and leached metal components; d. the oil compounds obtained in step c are discharged into an oil-water separation device along with the electrolyte, and after separation, an upper layer of oil compounds containing particles and a lower layer of electrolyte solution are obtained, and the lower layer of electrolyte solution is returned to the electrolytic cell; e. the metal components obtained in step c migrate to the cathode under the action of the electric field force, and are enriched by electrodeposition to obtain a metal mixture. The method of the present invention simultaneously realizes the deoiling of the wet waste oil-containing catalyst and the separation and recovery of the inorganic metal components, with a short extraction time and high working efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical hydrometallurgy, and specifically relates to a method for wet recovery of oil-containing waste catalyst, and particularly relates to a device for wet recovery of oil-containing waste catalyst. Background Art

[0002] Oily waste catalysts are common in the petrochemical, coal chemical, material synthesis, metallurgy, pharmaceutical and other industries. Such waste catalysts are mostly deactivated due to excessive adsorption or deposition of oil compounds or metal compounds on the surface. There are many organic compounds adsorbed on the surface of waste catalysts, usually containing 5-20% of oily substances, such as hydrocarbon oil, organic gel, etc. Due to the large surface area of ​​waste catalysts and the adsorption of carbon deposited on the surface, it is difficult to deoil waste catalysts. Waste catalysts are also important secondary resources of metal elements. For example, the content of metals such as vanadium, nickel, cobalt, molybdenum, tungsten, and aluminum in waste petrochemical catalysts is relatively high. Before extracting these metal elements, it is generally necessary to remove the oil components. Therefore, deactivated waste catalysts are important secondary solid waste resources, and their processing and recycling issues have long been hot issues in the fields of petrochemicals, coal chemical industry, metallurgy, environmental engineering, etc. The composition and structure of oil compounds and metal compounds in oily waste catalysts are relatively complex. Recycling often uses pre-deoiling treatment and then extraction of metal components. The relevant technologies for treating waste catalysts are pyrometallurgy and hydrometallurgy.

[0003] The typical process of pyrometallurgical treatment of oily waste catalysts is to roast at a low temperature of 600-900℃ to remove oil, and then roast at a high temperature of 1200-1900℃ to melt the metal components in the waste catalyst into a multi-metal alloy, and the metal elements are fixed and recovered. In the process, both oil removal roasting and high-temperature roasting are prone to produce polluting flue gas containing SO2, CO, H2S, etc., which are relatively harmful to the environment. When the oily waste catalyst is wet processed, the subsequent wet smelting is significantly affected by the organic compounds it contains, so it is generally necessary to pre-deoil before wet metal extraction. In order to obtain a better pretreatment effect, it is relatively effective to pre-treat the de-oiling process with oxidation roasting, because oxidation roasting can remove oil and transform the original phase of metal minerals in the waste catalyst, making it easier to extract by wet method. The polluted gas generated by the pyrometallurgical pretreatment process is still a difficult problem to control. However, the oxidation roasting process does not effectively recover or utilize the oil in the waste catalyst. For example, CN185460A discloses a method for extracting vanadium, molybdenum, nickel and aluminum from waste aluminum-based catalysts, CN105274344A discloses a method for recovering vanadium and molybdenum from waste petroleum catalysts, and CN105274343A discloses a method for extracting tungsten and nickel from petroleum hydrogenation catalysts. The waste catalysts are first decarbonized and deoiled by oxidative roasting, and then roasted at a high temperature to convert the metal mineral phase into a fusible phase and then extract the metal. When the waste catalyst is treated with this type of process, the phase transformation between oil and metal mineral is carried out in two steps. Not only are organic hydrocarbon substances not well utilized, but the deoiling or sodium roasting time is long and the energy consumption is high. The process produces harmful gases that are easy to harm the environment.

[0004] Therefore, there is an urgent need to provide an environmentally friendly method for treating oil-containing waste catalysts. Summary of the invention

[0005] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0006] The disposal of waste catalysts containing oil has always been a common problem in resource utilization and environmental protection. Waste catalysts contain a large amount of oil components and higher metal element content than conventional ores, and are important secondary organic energy and mineral resources.

[0007] In the related art, when using wet or pyrometallurgical processes to treat oily waste catalysts, the problems that need to be solved are mainly manifested in two steps. One is the effective separation of oily compounds and inorganic materials, and the other is how to extract metals from inorganic materials more easily and effectively after deoiling. The environmental protection problems caused by the flue gas generated by pyrometallurgical treatment or pretreatment of waste hydrogenation catalysts are insurmountable bottlenecks. Therefore, wet deoiling is the key discovery of the utilization of oily waste catalysts. Wet deoiling is essentially achieved by changing the oil-water interfacial tension. CN105498860A discloses a method for deoiling oily waste catalysts. By adding sodium dodecyl sulfate and caustic soda to reduce the surface tension of water, 95% of the residual oil on the surface of the waste catalyst is removed at low temperature. However, after the oil substances are dissolved in water, they are not only not utilized, but also the oil-water mixed solution is difficult to dispose of, resulting in a waste of resources. The added surfactant sodium dodecyl sulfate itself has a certain toxicity, and the secondary pollution problem is serious.

[0008] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiment of the present invention proposes a wet recovery method for oil-containing waste catalyst, which can simultaneously achieve the deoiling of the wet waste catalyst containing oil and the separation and recovery of inorganic metal components, without the need for pyrolysis and material crushing, without the generation of waste residue, waste gas and waste water, and with significant environmental effects.

[0009] A wet recovery method for oil-containing waste catalyst according to the first embodiment of the present invention comprises the following steps:

[0010] a. Filling the electrochemical reaction chamber between the cathode and the rotating anode of the rotating electrode electrolytic cell with oil-containing spent catalyst particles;

[0011] b. circulating an acidic electrolyte into the electrolytic cell;

[0012] c. inputting voltage to the electrolytic cell, and electrochemically separating the oily waste catalyst to obtain oil compounds and leached metal components;

[0013] d. The oily compounds obtained in step c are discharged into an oil-water separation device along with the electrolyte, and after separation, an upper layer of oily compounds containing particles and a lower layer of electrolyte solution are obtained, and the lower layer of electrolyte solution is returned to the electrolytic cell;

[0014] e. The metal components obtained in step c migrate to the cathode under the action of the electric field force and are enriched by electrodeposition to obtain a metal mixture.

[0015] The advantages and technical effects brought by the independent claims of the embodiments of the first aspect of the present invention are as follows: 1. The embodiments of the present invention place the oil-containing waste catalyst in an aqueous electrolyte. When an electric field is applied in the aqueous phase, since the dielectric constant of water is much higher than that of oil, the oil substance can be regarded as an insulating medium and the water is polarized. Due to the polarization of water molecules, the oil-water interfacial tension will increase significantly in a certain direction, so that the probability of desorption of the oil substance from the surface of the waste catalyst is significantly increased, and the detached small oil droplets are rejected and form large oil droplets that float up, thereby achieving the deoiling of the waste catalyst; in this process, under the influence of the electric field force, the redox active substances on the surface of the waste catalyst are electrolytically dissociated, and the metal compounds are electrochemically dissolved into the aqueous electrolyte solution, catalytically electrolyzed into ions in the acidic electrolyte, and transferred from the solid phase to the aqueous solution phase. After the metal ions in the aqueous solution phase enter the solution, they move to the cathode in a directional manner, thereby achieving Selective separation of metal elements; 2. The method of the embodiment of the present invention adopts a rotating electrode, and the electrochemical reaction process is carried out through the relative high-speed movement of the electrolyte and the electrode, which can avoid the influence of unfavorable factors on electrochemical separation such as low current efficiency and increased concentration polarization caused by the slow flow of the solution during the electrolysis process of the traditional flat frame electrolytic cell; 3. The method of the embodiment of the present invention simultaneously realizes the wet deoiling of oil-containing waste catalyst and the separation and recovery of inorganic metal components, reduces the extraction time, and has high work efficiency; 4. The method of the embodiment of the present invention realizes selective electrolysis, and the output of the liquid and solid components to be separated and recovered is simple, and oil products, hydrophobic inorganic particle products, metal component products dissolved and cathode deposited, electrolytic leaching residue products, etc. are obtained. There is no waste residue, waste gas and wastewater discharge in the process, the environmental effect is significant, the product is convenient for subsequent wet recovery, and the oil and metal recovery rate is high, realizing the maximum utilization of resources.

[0016] According to the wet recovery method of oil-containing waste catalyst according to an embodiment of the present invention, in the step b, the acidic electrolyte is selected from sulfuric acid, hydrochloric acid or nitric acid.

[0017] According to the wet recovery method of oil-containing waste catalyst in the embodiment of the present invention, in the step b, the mass percentage of the acidic electrolyte is 2-30%.

[0018] According to the wet recovery method of oil-containing waste catalyst in an embodiment of the present invention, in the step c, the potential difference between the cathode and anode in the electrolytic cell is 0.3-5.0V.

[0019] According to the wet recovery method of oil-containing waste catalyst in an embodiment of the present invention, in the step c, the potential difference between the cathode and anode in the electrolytic cell is 1.0-3.0V.

[0020] According to the wet recovery method of oil-containing waste catalyst of an embodiment of the present invention, in the step d, the obtained particle-containing oil compound is filtered to obtain solid-phase difficult-to-electrolyze hydrophobic inorganic particles and filtrate oil compounds.

[0021] According to an embodiment of the second aspect of the present invention, there is also provided a wet recovery device for oil-containing waste catalyst, comprising a rotating electrode electrolytic cell and an oil-water separation device, wherein a rotating anode is arranged in the middle of the rotating electrode electrolytic cell, a fixed cathode is arranged around the rotating anode, an electrochemical reaction chamber is provided between the rotating anode and the cathode, an oil-water discharge port is arranged on the upper part of the rotating electrode electrolytic cell, the oil-water discharge port is connected to the inlet of the oil-water separation device, and the water phase outlet of the oil-water separation device is connected to the electrolyte inlet of the rotating electrode electrolytic cell.

[0022] The advantages and technical effects brought by the independent claims of the embodiment according to the second aspect of the present invention are as follows: 1. The device of the embodiment of the present invention adopts a rotating electrode, and the electrochemical reaction process is carried out by the relative high-speed movement of the electrolyte and the electrode, which can avoid the influence of the slow flow of the solution in the electrolysis process of the traditional flat frame electrolytic cell, such as low current efficiency and increased concentration polarization, on the unfavorable factors of electrochemical separation; 2. The device of the embodiment of the present invention simultaneously realizes the wet deoiling of the oily waste catalyst and the separation and recovery of the inorganic metal components, reduces the extraction time, has high working efficiency, has no waste residue, waste gas and waste water, and has significant environmental effects; 3. The liquid and solid components to be separated and recovered produced by the device of the embodiment of the present invention are simple, and the recovery rate of oil and metal is high, realizing the maximum utilization of resources. The device of the embodiment of the present invention is used to realize the wet recovery method of the oily waste catalyst of the embodiment of the first aspect of the present invention, which has all the beneficial effects of the wet recovery method of the oily waste catalyst, which will not be repeated here.

[0023] The wet recovery device for oil-containing waste catalyst according to an embodiment of the present invention further comprises a filtering device, wherein the inlet of the filtering device is connected to the oil phase outlet of the oil-water separation device.

[0024] According to the wet recovery device for oil-containing waste catalyst in an embodiment of the present invention, a leached residue discharge port is provided at the bottom of the rotating electrode electrolytic cell.

[0025] According to the wet recovery device for oil-containing waste catalyst according to an embodiment of the present invention, the rotating anode is an inert rotating anode. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a wet recovery device for oil-containing waste catalyst according to an embodiment of the present invention.

[0027] Figure numerals: 1-rotating electrode electrolytic cell; 2-electrochemical reaction chamber; 3-cathode; 4-rotating anode; 5-power transmission cabinet; 6-rotating power equipment; 7-electrolyte inlet; 8-oil-water discharge port; 9-leached residue discharge port; 10-stop valve; 11-stop valve; 12-oil-water separation device; 13-stop valve; 14-lower electrolyte buffer tank; 15-three-way valve; 16-acidity meter and regulator; 17-electrolyte circulation pump; 18-flow meter; 19-electrolyte recovery device; 20-stop valve; 21-upper oil collection equipment; 22-stop valve; 23-filter pressure delivery pump; 24-filtration equipment; 25-oil collecting box; 26-hydrophobic inorganic particle collection box; 27-stop valve; 28-leached residue collection box; 29-electrolyte storage tank. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0029] A wet recovery method for oil-containing waste catalyst according to the first embodiment of the present invention comprises the following steps:

[0030] a. Filling the electrochemical reaction chamber between the cathode and the rotating anode of the rotating electrode electrolytic cell with oil-containing spent catalyst particles;

[0031] b. first, circulating an acidic electrolyte into the electrolytic cell;

[0032] c. inputting voltage to the electrolytic cell, and electrochemically separating the oily waste catalyst to obtain oil compounds and leached metal components;

[0033] d. The oily compounds obtained in step c are discharged into an oil-water separation device along with the electrolyte, and after separation, an upper layer of oily compounds containing particles and a lower layer of electrolyte solution are obtained, and the lower layer of electrolyte solution is returned to the electrolytic cell;

[0034] e. The metal components obtained in step c migrate to the cathode under the action of the electric field force and are enriched by electrodeposition to obtain a metal mixture.

[0035] The advantages and technical effects brought by the independent claims of the embodiments of the first aspect of the present invention are as follows: 1. The embodiments of the present invention place the oil-containing waste catalyst in an aqueous electrolyte. When an electric field is applied in the aqueous phase, since the dielectric constant of water is much higher than that of oil, the oil substance can be regarded as an insulating medium and the water is polarized. Due to the polarization of water molecules, the oil-water interfacial tension will increase significantly in a certain direction, so that the probability of desorption of the oil substance from the surface of the waste catalyst is significantly increased, and the detached small oil droplets are rejected and form large oil droplets that float up, thereby achieving the deoiling of the waste catalyst; in this process, under the influence of the electric field force, the redox active substances on the surface of the waste catalyst are electrolytically dissociated, and the metal compounds are electrochemically dissolved into the aqueous electrolyte solution, catalytically electrolyzed into ions in the acidic electrolyte, and transferred from the solid phase to the aqueous solution phase. After the metal ions in the aqueous solution phase enter the solution, they move to the cathode in a directional manner, thereby achieving Selective separation of metal elements; 2. The method of the embodiment of the present invention adopts a rotating electrode, and the electrochemical reaction process is carried out through the relative high-speed movement of the electrolyte and the electrode, which can avoid the influence of unfavorable factors on electrochemical separation such as low current efficiency and increased concentration polarization caused by the slow flow of the solution during the electrolysis process of the traditional flat frame electrolytic cell; 3. The method of the embodiment of the present invention simultaneously realizes the wet deoiling of oil-containing waste catalyst and the separation and recovery of inorganic metal components, reduces the extraction time, and has high work efficiency; 4. The method of the embodiment of the present invention realizes selective electrolysis, and the output of the liquid and solid components to be separated and recovered is simple, and oil products, hydrophobic inorganic particle products, metal component products dissolved and cathode deposited, electrolytic leaching residue products, etc. are obtained. There is no waste residue, waste gas and wastewater discharge in the process, the environmental effect is significant, the product is convenient for subsequent wet recovery, and the oil and metal recovery rate is high, realizing the maximum utilization of resources.

[0036] According to the wet recovery method of oil-containing waste catalyst in an embodiment of the present invention, in the step b, the acidic electrolyte is selected from sulfuric acid, hydrochloric acid or nitric acid; there is no particular limitation on the acidic electrolyte and the concentration of the acidic electrolyte in the embodiment of the present invention, which can be determined based on 1.0-1.5 times the acid concentration required for complete leaching of the metal components contained in the waste catalyst. Preferably, the mass percentage of the acidic electrolyte is 2-30%.

[0037] According to the wet recovery method of oil-containing waste catalyst in the embodiment of the present invention, wherein, in the step c, the potential difference between the cathode and cathode in the electrolytic cell is 0.3-5.0 V, preferably 1.0-3.0 V. In the embodiment of the present invention, the potential difference between the cathode and cathode is optimized, so that the adopted potential difference can not only provide sufficient driving force for the oil substance to accelerate the movement of the oil compound, but also satisfy the directional movement and deposition of the metal cations toward the cathode, and avoid the electrolysis of the oil substance. If the potential difference between the cathode and cathode is too large, the oxidizing gas such as O2 produced by the electrolysis of water will increase, react with the metal deposition, and affect the leaching process, thereby reducing the recovery rate of the inorganic metal components.

[0038] According to the wet recovery method of oil-containing waste catalysts in an embodiment of the present invention, in the step d, the obtained particle-containing oil compound is filtered to obtain solid-phase hydrophobic inorganic particles that are difficult to electrolyze and filtrate oil compounds. In the embodiment of the present invention, the particle-containing oil compound is further filtered and separated to obtain hydrophobic inorganic particles that are difficult to electrolyze, which can be used for subsequent processing and refining, and the filtrate is the recovered oil compound product.

[0039] like Figure 1 As shown, according to an embodiment of the second aspect of the present invention, there is also provided a wet recovery device for oil-containing waste catalyst, comprising a rotating electrode electrolytic cell 1 and an oil-water separation device 12, wherein a rotating anode 4 is arranged in the middle of the rotating electrode electrolytic cell 1, preferably an inert rotating anode, and a fixed cathode 3 is arranged around the rotating anode 4, and an electrochemical reaction chamber 2 is arranged between the rotating anode 4 and the cathode 3, and an oil-water discharge port 8 is arranged on the upper part of the rotating electrode electrolytic cell 1, and the oil-water discharge port 8 is connected to the inlet of the oil-water separation device 12, and the water phase outlet of the oil-water separation device 12 is connected to the electrolyte inlet 7 of the rotating electrode electrolytic cell.

[0040] The advantages and technical effects brought by the independent claims of the embodiment according to the second aspect of the present invention are as follows: 1. The device of the embodiment of the present invention adopts a rotating electrode, and the electrochemical reaction process is carried out by the relative high-speed movement of the electrolyte and the electrode, which can avoid the influence of the slow flow of the solution in the electrolysis process of the traditional flat frame electrolytic cell, such as low current efficiency and increased concentration polarization, on the unfavorable factors of electrochemical separation; 2. The device of the embodiment of the present invention simultaneously realizes the wet deoiling of the oily waste catalyst and the separation and recovery of the inorganic metal components, reduces the extraction time, has high working efficiency, has no waste residue, waste gas and waste water, and has significant environmental effects; 3. The liquid and solid components to be separated and recovered produced by the device of the embodiment of the present invention are simple, and the recovery rate of oil and metal is high, realizing the maximum utilization of resources. The device of the embodiment of the present invention is used to realize the wet recovery method of the oily waste catalyst of the embodiment of the first aspect of the present invention, which has all the beneficial effects of the wet recovery method of the oily waste catalyst, which will not be repeated here.

[0041] The wet recovery device for the oil-containing waste catalyst according to the embodiment of the present invention further comprises a filtering device 24, the inlet of the filtering device 24 is connected to the oil phase outlet of the oil-water separation device 12. In the embodiment of the present invention, by setting the filtering device, the particle-containing oil compound separated by the oil-water separation device 12 is further filtered and separated, and the hydrophobic inorganic particles that are difficult to electrolyze are recovered, which can be used for subsequent processing and refining, and the filtrate is the recovered oil compound product.

[0042] According to the wet recovery device of the oil-containing waste catalyst of the embodiment of the present invention, a slag discharge port 9 is provided at the bottom of the rotating electrode electrolytic cell 1. In the device of the embodiment of the present invention, the metal compounds that are difficult to electrolyze in the oil-containing waste catalyst remain in the slag phase, are discharged and recovered through the slag discharge port, and are returned to the catalyst preparation system.

[0043] Refer to the following Figure 1 The working process of the wet recovery device of the oil-containing waste catalyst according to the embodiment of the present invention is described in detail.

[0044] The electrochemical reaction chamber 2 between the cathode 3 and the rotary anode 4 of the rotating electrode electrolytic cell 1 is filled with oily waste catalyst particles. The oily compounds in the waste catalyst contain 2%-25% of oily compounds adsorbed on the surface of the waste catalyst, and the surface of the waste catalyst adsorbs more multi-metallic compound components. The acid electrolyte solution is prepared in the electrolyte storage tank 29, the stop valve 11 is opened, the stop valve 20 is closed, and the stop valve 27 upstream of the leaching residue collection box 28 is closed. The electrolyte passes through the oil-water separation device 12 and the lower electrolyte buffer tank 14, and is added to the electrochemical reaction chamber 2 through the electrolyte inlet 7 by the electrolyte circulation pump 17. The electrolyte gradually immerses the oily waste catalyst particles filled in the electrochemical reaction chamber 2 from bottom to top, and finally introduces enough electrolyte to circulate out of the electrolytic cell 1 through the oil-water discharge port 8, and enters the oil-water separation device 12 after passing through the stop valve 10, so as to realize the pre-circulation of the electrolyte in the electrochemical reaction chamber. The electrolyte circulation flow rate is achieved by controlling the rate of the electrolyte circulation pump 17 through the flow meter 18, and the acidity required for the electrochemical reaction is adjusted and controlled by the acidity meter and the regulator 16 to keep the electrolyte acidity at a constant level.

[0045] After the electrolyte circulates stably in the electrochemical reaction chamber 2, the rotary power device 6 is started to rotate the rotary anode 4, and the power transmission cabinet 5 is used to supply power to perform catalytic electrolytic separation on the oil-containing waste catalyst, and electrochemical reactions such as deoiling reaction, metal component leaching reaction and metal component cathode deposition are completed in the electrochemical reaction chamber 2.

[0046] There is an obvious polarization difference between the oil substances on the surface of the waste catalyst and the electrolyte, and the oil substances are gradually squeezed out from the surface of the waste catalyst to form fine oil droplets. Since the density of the small oil droplets is relatively small, they are gradually floated to the surface of the reaction chamber 2 under the influence of the upward rotating buoyancy of the rotating electrode. The small oil droplets merge to form an oil film layer, which is introduced into the oil-water separation device 12 with the circulation of the electrolyte. After standing, the oil compounds containing particles are distributed in the upper layer, and the upper layer is discharged by gravity through the shut-off valve 20 and flows into the upper oil collection device 21 to obtain an oil mixture containing hydrophobic inorganic particles. The oil mixture contains some hydrophobic fine-particle metal components that are difficult to electrolyze and leach and adsorb on the surface of the waste catalyst, such as MoS2, C or electrolytically separated elemental S contained in the waste catalyst. The oil mixture collected in the upper layer enters the filtering device 24 through the shut-off valve 22 and the filter press delivery pump 23 to separate the hydrophobic inorganic particles entrained in the oil. The filter residue phase is the mixed hydrophobic inorganic particles. The separated hydrophobic inorganic particles are collected in the hydrophobic inorganic particle collection box 26 and can be recovered by wet method or fire method. The oil component is collected by the oil collecting box 25, thereby realizing the separation of oil and hydrophobic products.

[0047] The components to be leached or electrolyzed adsorbed on the surface of the waste catalyst, such as metal compounds containing V, Ni, Co, Al, etc., are preferentially dissolved into the electrolytic aqueous phase solution through electrolyte leaching under the influence of the electric field force in the electrochemical reaction chamber 2, and then directed to move to the cathode 3 for deposition under the action of the electric field force. The electrolyte circulates from bottom to top and flows out through the oil-water discharge port 8, and enters the oil-water separation device 12. After static separation, the electrolyte aqueous solution in the lower layer passes through the shut-off valve 13 and enters the lower electrolyte buffer tank 14. The electrolyte in the buffer tank is controlled by the three-way valve 15. The electrolyte flows through the acidity meter 16 and the flow meter 17 and returns to the rotating electrode electrolytic cell 1 for circulation. When the electrolyte is enriched with a certain concentration of metal components, it can also be introduced into the electrolyte collection device 19 to wet-recover the electrolytic components that have been leached but not deposited on the cathode.

[0048] After the oil compounds and cathode deposited metals are recovered, the undissolved spent catalyst leaching residue can be discharged from the leaching residue discharge port 9 through the cut-off valve 27 into the leaching residue collection box 28 for further recycling. In the embodiment of the present invention, the cathode deposited metals and the metals in the slag phase that are difficult to electrolyze can be recycled by conventional methods.

[0049] Example 1

[0050] The mass percentage of oil components in a certain desulfurization and hydrogenation waste catalyst is 12%, and the contents of vanadium, nickel, molybdenum, cobalt, aluminum and sulfur are 5.4%, 3.3%, 0.9%, 1.2%, 27.3% and 8.3% respectively. The contents of other metals are relatively low; the catalyst contains a large amount of oil compounds and sulfur. The device in the embodiment of the present invention is used, 5% sulfuric acid solution is used as the acidic electrolyte aqueous solution, the voltage is input, and the potential difference between the cathode and the anode is 3V, which can dissolve vanadium, nickel and cobalt. After 120 minutes of electrochemical reaction separation at room temperature, 98% of the oil compounds are collected in the oil collection box, more than 90% of the molybdenum compounds and S are enriched in the hydrophobic inorganic particles in the form of single substances, and the recovery rates of vanadium, nickel, cobalt and aluminum deposited at the cathode are all above 98%.

[0051] Example 2

[0052] Waste aluminum-based platinum-palladium catalyst, which contains 2.5% oil. The device in the embodiment of the present invention is used, 3.5% hydrochloric acid is used as the acidic electrolyte aqueous solution, the voltage is input, and the potential difference between the cathode and the anode is 2V. Electrochemical dissolution is carried out in the electrochemical reaction chamber, and the oil is selectively removed and platinum-palladium is deposited by leaching the cathode. The platinum-palladium extraction rate is more than 99%, while the aluminum leaching rate is less than 20%. The remaining high-aluminum product is discharged as leaching residue and used as a high-purity alumina raw material. The recovery rate of oil compounds reaches 95%.

[0053] Example 3

[0054] The waste SCR catalyst has an oil component of 4.5%. Using the device in the embodiment of the present invention, 5% nitric acid is used as the acid electrolyte aqueous solution, at 40°C, the input voltage, the anode and cathode potential difference is 1.5V, and electrochemical catalytic leaching is performed. The recovery rate of vanadium and nickel reaches more than 97%, and the recovery rate of oil compounds is more than 96%.

[0055] Example 4

[0056] The method is the same as that of Example 1, except that the potential difference between the cathode and the anode is 5 V. The recovery rate of the oil compound using the method of Example 4 is 93%, the recovery rates of vanadium, nickel, cobalt and aluminum deposited at the cathode are all above 98%, and the recovery rate of molybdenum compounds and S is 87%.

[0057] Comparative Example 1

[0058] The method is the same as that of Example 1, except that the potential difference between the cathode and the anode is 6 V. The recovery rate of oil compounds using the method of Comparative Example 1 is 87%, the recovery rate of cathode deposited vanadium, nickel, cobalt, and aluminum is 94%, and the recovery rate of molybdenum compounds and S is 82%.

[0059] Comparative Example 2

[0060] The method is the same as that of Example 1, except that in the wet recovery device for the oil-containing waste catalyst, a fixed anode is used instead of a rotating electrode as the anode. The recovery rate of the oil compound using the method of Comparative Example 2 is 76%, the recovery rate of the cathode deposited vanadium, nickel, cobalt, and aluminum is 90%, and the recovery rate of the molybdenum compound and S is 72%.

[0061] Comparative Example 3

[0062] The method is the same as that of Example 1, except that in the wet recovery device for oil-containing waste catalyst, the rotating electrode in the middle of the electrolytic cell is the cathode, and the anode is a fixed electrode arranged around the rotating cathode. The recovery rate of oil compounds using the method of Comparative Example 3 is 70%, the recovery rate of vanadium, nickel, cobalt, and aluminum deposited at the cathode is 51%, and the recovery rate of molybdenum compounds and S is 63%. In Comparative Example 3, the cathode and the anode are switched, and the recovery rate of oil compounds and inorganic metal components is seriously reduced. This is because, on the one hand, the metal deposition reaction on the cathode requires a larger specific surface area, but the specific surface area of ​​the rotating electrode is not too large, which affects the metal deposition; on the other hand, the polarization of the water phase in the electrochemical reaction chamber is from the cathode to the anode. After the cathode and the anode are switched, the water molecules will squeeze the oil molecules inward, and the oil molecules will move close to the rotating electrode, which is not conducive to the rapid floating separation of oil substances in the waste catalyst.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0065] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0066] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A wet recovery method for oil-containing waste catalyst, characterized in that: The steps include: a. Filling the electrochemical reaction chamber between the cathode and the rotating anode of the rotating electrode electrolytic cell with oil-containing spent catalyst particles; b. Circulating an acidic electrolyte into the electrolytic cell, wherein the concentration of the acidic electrolyte is determined based on 1.0-1.5 times the acid concentration required for complete leaching of the metal components contained in the waste catalyst; c. Inputting voltage to the electrolytic cell, wherein the potential difference between the cathode and anode in the electrolytic cell is 0.3-5.0 V, and the oily waste catalyst is electrochemically separated to obtain oil compounds and leached metal components; d. The oily compounds obtained in step c are discharged into an oil-water separation device along with the electrolyte, and after separation, an upper layer of oily compounds containing particles and a lower layer of electrolyte solution are obtained, and the lower layer of electrolyte solution is returned to the electrolytic cell; e. The metal components obtained in step c migrate to the cathode under the action of the electric field force and are enriched by electrodeposition to obtain a metal mixture.

2. The wet recovery method of oil-containing waste catalyst according to claim 1, characterized in that: In the step b, the acidic electrolyte is selected from sulfuric acid, hydrochloric acid or nitric acid.

3. The wet recovery method of oil-containing waste catalyst according to claim 1 or 2, characterized in that: In the step b, the mass percentage of the acidic electrolyte is 2-30%.

4. The wet recovery method of oil-containing waste catalyst according to claim 1, characterized in that: In the step c, the potential difference between the cathode and anode in the electrolytic cell is 1.0-3.0V.

5. The wet recovery method of oil-containing waste catalyst according to claim 1, characterized in that: In the step d, the obtained particle-containing oil compounds are filtered to obtain solid-phase hydrophobic inorganic particles that are difficult to electrolyze and filtrate oil compounds.

6. A device used in the wet recovery method of oil-containing waste catalyst according to any one of claims 1 to 5, characterized in that: The invention comprises a rotating electrode electrolytic cell and an oil-water separation device, wherein a rotating anode is arranged in the middle of the rotating electrode electrolytic cell, a fixed cathode is arranged around the rotating anode, an electrochemical reaction chamber is arranged between the rotating anode and the cathode, an oil-water discharge port is arranged on the upper part of the rotating electrode electrolytic cell, the oil-water discharge port is connected to the inlet of the oil-water separation device, and the water phase outlet of the oil-water separation device is connected to the electrolyte inlet of the rotating electrode electrolytic cell.

7. The device used in the wet recovery method of oil-containing waste catalyst according to claim 6 is characterized in that: It also includes a filtering device, the inlet of which is connected to the oil phase outlet of the oil-water separation device.

8. The device used in the wet recovery method of oil-containing waste catalyst according to claim 6 is characterized in that: A slag discharge port is arranged at the bottom of the rotating electrode electrolytic cell.

9. The device used in the wet recovery method of oil-containing waste catalyst according to claim 6 is characterized in that: The rotating anode is an inert rotating anode.

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