Method for preparing vanadyl sulfate electrolyte by using waste residue oil hydrogenation catalyst

Abstract

The invention belongs to the field of waste residue oil hydrogenation catalyst recovery, and particularly relates to a method for preparing vanadyl sulfate electrolyte by using a waste residue oil hydrogenation catalyst. According to the method, the waste residue oil hydrogenation catalyst is used as a raw material, the high-purity vanadyl sulfate solution is prepared through the preparation procedures of roasting, leaching, impurity removal, reduction, extraction and reverse extraction, on one hand, the problem of solid waste treatment is solved, on the other hand, vanadium is selectively recycled from the high-concentration vanadium-containing solution through a solvent extraction method, and the production cost is greatly reduced. And the obtained vanadyl sulfate solution is high in purity, few in impurities and high in production efficiency.

Description

Technical Field

[0001] The invention belongs to the field of waste residue oil hydrogenation catalyst recovery, and specifically relates to a method for preparing vanadyl sulfate electrolyte by utilizing waste residue oil hydrogenation catalyst. Background Art

[0002] The preparation methods of vanadium sulfate solution mainly include chemical synthesis, electrolysis, solvent extraction, etc.: (1) The chemical synthesis method is to use vanadium oxide or vanadium salt as raw material, dissolve it in sulfuric acid solution, add reducing agent, and reduce it by high temperature heating to prepare vanadium electrolyte with different concentrations and different valence states. (2) The electrolysis method is to use V2O5 or metavanadate as raw material, add vanadium-containing raw material to sulfuric acid solution in the negative electrode electrolytic cell, add H2SO4 of the same concentration to the positive electrode electrolytic cell, connect the two poles of the battery to a DC power supply, and V2O5 or metavanadate is reduced on the surface of the negative electrode to obtain a low-valent vanadium solution. (3) The solvent extraction method is to use vanadium-containing solution as the extraction stock solution, such as stone coal leachate, vanadium-titanium magnetite leachate, vanadium-containing wastewater, etc. According to the extraction selectivity of different extractants for different metals, high-purity and high-concentration vanadium electrolyte is prepared under comprehensive conditions such as extraction, washing, and stripping.

[0003] The above commonly used preparation methods have the following disadvantages, such as slow solid dissolution rate and small production volume each time in chemical reduction method, difficult to eradicate reducing agents such as oxalic acid, and the generation of polluting gases such as CO2, SO2, and Cl2. The electrolysis method has high requirements on raw material purity and electrode performance, low production efficiency, high cost, and huge energy consumption, and currently cannot meet the requirements of industrial large-scale production. The solvent extraction method requires multi-stage extraction, complex process, high volume ratio of organic phase to aqueous phase during extraction, low volume ratio of organic phase to aqueous phase during stripping, and low production efficiency. Summary of the invention

[0004] Based on the above technical background, the main purpose of the present invention is to provide a method for preparing vanadyl sulfate electrolyte using waste residue oil hydrogenation catalyst to overcome the shortcomings of the prior art.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes: The present invention provides a method for preparing a vanadyl sulfate electrolyte using a waste residue oil hydrogenation catalyst, the method comprising the following steps: Step 1, oxidatively roasting the waste oil hydrogenation catalyst, then adding soda ash, mixing and drying, then sodium roasting, adding water to the sodium roasted material for leaching, and obtaining a vanadium-molybdenum leaching solution; Step 2, filtering and washing the vanadium-molybdenum-containing leachate, then adding acid to adjust the pH, then adding alkali for saponification, and extracting the saponified leachate to obtain an organic phase and an aqueous phase; Step 3, washing the organic phase, and then adding a sulfuric acid solution and a reducing agent for stripping to obtain a vanadyl sulfate solution; Step 4: Wash the organic phase after stripping, then add alkali to strip molybdenum to obtain a molybdenum-containing solution.

[0006] In step 1, Preferably, the oxidation roasting conditions are: the oxidation roasting temperature is 400-800° C., and the oxidation roasting time is 3-8 hours.

[0007] Preferably, the molar ratio of soda ash to the oxidatively calcined waste oil hydrogenation catalyst is (1.05-4):1, and the molar number of the oxidatively calcined waste oil hydrogenation catalyst is the sum of the molar numbers of V2O5 and MoO3.

[0008] Preferably, the conditions for the sodium calcination are: the sodium calcination temperature is 400-800° C., and the sodium calcination time is 3-8 hours.

[0009] Preferably, the water leaching conditions are: the mass ratio of the sodium roasted material to water is 1: (2.5-5), the leaching temperature is 40-90° C., and the leaching time is 1-4 hours.

[0010] In step 2, Preferably, after filtering and washing, sulfuric acid is added to adjust the pH of the vanadium-molybdenum leaching solution to 1.5-2.2; Preferably, the saponification conditions are: adding a soda ash solution or ammonia water for saponification at 20-30° C., and the saponification rate is 0-80%.

[0011] Preferably, the extraction conditions are: adding an extractant, a modifier and a diluent, performing multi-stage countercurrent extraction at 20-30° C., an extraction time of 3-10 min, and extraction O / A=1:(1-10).

[0012] In step 3, Preferably, the reducing agent is selected from one or more of SO2, H2, sodium sulfite, sodium bisulfite, sodium thiosulfate, and sodium pyrosulfite; Preferably, the amount of the reducing agent added is 0.5% to 5% of the mass of the organic phase.

[0013] Preferably, the stripping conditions are: multi-stage countercurrent stripping at 20-30° C., stripping time of 3-10 min, and stripping O / A = (10-1):1.

[0014] In step 4, Preferably, the conditions for stripping molybdenum are: adding sodium carbonate solution or ammonia water to strip molybdenum at 20-30° C., the stripping time is 3-10 min, and the stripping O / A = (20-1):1.

[0015] The beneficial effects of the present invention are: (1) The method of the present invention uses waste oil hydrogenation catalyst as the main raw material to prepare vanadyl sulfate solution using waste oil hydrogenation catalyst, which solves the problem of solid waste treatment on the one hand, and on the other hand, uses solvent extraction to selectively recover vanadium from high-concentration vanadium-containing solution, thereby greatly reducing production costs.

[0016] (2) The method of the present invention uses waste oil hydrogenation catalyst as raw material and prepares high-purity vanadyl sulfate solution through the preparation process of "roasting-leaching-impurity removal-reduction-extraction-strip extraction" to meet the demand for raw materials in the vanadium battery industry.

[0017] The present invention controls the impurity content and vanadium concentration in the leaching solution by controlling the calcination and leaching conditions of the waste residue oil hydrogenation catalyst; The present invention removes impurities by chemical precipitation, which can further reduce the impurity content in the leaching solution; The present invention preferentially uses gaseous reducing agents such as SO2 to avoid bringing impurities introduced by the reducing agent into the vanadyl sulfate solution, and the obtained vanadyl sulfate solution has high purity and high production efficiency; The present invention utilizes a solvent extraction method to selectively separate vanadium and molybdenum, and by adjusting the stripping process conditions, a vanadyl sulfate solution is directly obtained after stripping, thereby eliminating the post-treatment process and being more convenient.

[0018] The method of the present invention has good application prospects in the field of waste residue oil hydrogenation catalyst recovery and the field of preparing vanadyl sulfate solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the preparation process of the method for preparing vanadyl sulfate electrolyte using waste residue oil hydrogenation catalyst according to the present invention is shown. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below, and the characteristics and advantages of the present invention will become clearer and more distinct with the description.

[0021] Waste residue oil hydrogenation catalyst has been included in the list of hazardous wastes (HW50). It contains a lot of rare metals, generally with a V content of 1% to 20% (mass fraction, the same below), a Mo content of 3% to 20%, and an Al2O3 content of about 40%. The grade is much higher than that of the original ore. It is an important secondary resource with a high recovery value.

[0022] The present invention provides a method for preparing a vanadyl sulfate electrolyte using a waste residue oil hydrogenation catalyst. Figure 1 As shown, the method comprises the following steps: Step 1, oxidatively roasting the waste oil hydrogenation catalyst, then adding soda ash, mixing and drying, then sodium roasting, adding water to the sodium roasted material for leaching, and obtaining a vanadium-molybdenum leaching solution; Step 2, filtering and washing the vanadium-molybdenum-containing leachate, then adding acid to adjust the pH, then adding alkali for saponification, and extracting the saponified leachate to obtain an organic phase and an aqueous phase; Step 3, washing the organic phase, and then adding a sulfuric acid solution and a reducing agent for stripping to obtain a vanadyl sulfate solution; Step 4: Wash the organic phase after stripping, then add alkali to strip molybdenum to obtain a molybdenum-containing solution.

[0023] The above steps are described in detail below.

[0024] In step 1, the oxidation roasting conditions are: the oxidation roasting temperature is 400-800° C., and the oxidation roasting time is 3-8 hours.

[0025] Preferably, the oxidation roasting conditions are: the oxidation roasting temperature is 550° C., and the oxidation roasting time is 5 h.

[0026] The molar ratio of soda ash to the oxidatively calcined waste oil hydrogenation catalyst is (1.05-4):1, and the molar number of the oxidatively calcined waste oil hydrogenation catalyst is the sum of the molar numbers of V2O5 and MoO3.

[0027] Preferably, the molar ratio of soda ash to the oxidatively calcined waste oil hydrogenation catalyst is 2.5:1, and the molar number of the oxidatively calcined waste oil hydrogenation catalyst is calculated as the sum of the molar numbers of V2O5 and MoO3.

[0028] The drying conditions are: drying at 110-130° C. for 1-2 hours, preferably, drying at 120° C. for 1.5 hours.

[0029] The conditions of the sodium calcination are as follows: the sodium calcination temperature is 400-800° C., and the sodium calcination time is 3-8 hours.

[0030] Preferably, the conditions for the sodium calcination are: the sodium calcination temperature is 550° C., and the sodium calcination time is 6 hours.

[0031] The water leaching conditions are as follows: the mass ratio of the sodium roasted material to water is 1:(2.5-5), the leaching temperature is 40-90° C., and the leaching time is 1-4 hours.

[0032] Preferably, the water leaching conditions are: the mass ratio of the sodium roasted material to water is 1:4, the leaching temperature is 75° C., and the leaching time is 2.5 h.

[0033] The vanadium-containing molybdenum leaching solution mainly contains sodium vanadate, sodium molybdate and sodium carbonate, and its pH value is 9-11. In the vanadium-containing molybdenum leaching solution, the vanadium concentration is 10-40 g / L, and the molybdenum concentration is 10-40 g / L.

[0034] In step 2, after filtering and washing with water, sulfuric acid is added to adjust the pH of the vanadium-molybdenum leaching solution to 1.5-2.2.

[0035] The saponification conditions are: adding a soda solution or ammonia water for saponification at 20-30° C., and the saponification rate is 0-80%.

[0036] Preferably, the saponification conditions are: adding ammonia water for saponification at 25° C., and the saponification rate is 70%.

[0037] The extraction conditions are: multi-stage countercurrent extraction at 20-30° C., extraction time of 3-10 min, extraction O / A (volume ratio of organic phase to aqueous phase) = 1: (1-10).

[0038] Preferably, the extraction conditions are: adding an extractant, a modifier and a diluent, performing multi-stage countercurrent extraction at 25° C., the extraction time is 5 min, and after extraction, O / A (volume ratio of organic phase to aqueous phase) = 1:3.

[0039] The volume ratio of the extractant, the modifier and the diluent is 10-30:0-10:60-80.

[0040] Preferably, the volume ratio of the extractant, the modifier and the diluent is 20:5:70.

[0041] The extractant is selected from one or more of TOA (trioctylamine), N235 (trialkyl tertiary amine), N263 (methyltrialkylammonium chloride) and TBP (tributyl phosphate), preferably TOA.

[0042] The modifier is sec-octanol or isooctyl alcohol. The modifier can avoid the formation of the third phase.

[0043] The diluent is kerosene or DT-100.

[0044] In step 3, the reducing agent is selected from one or more of SO2, H2, sodium sulfite, sodium bisulfite, sodium thiosulfate, and sodium metabisulfite.

[0045] Preferably, the reducing agent is SO2 or sodium thiosulfate.

[0046] The amount of the reducing agent added is 0.5% to 5% of the mass of the organic phase. Preferably, the amount of the reducing agent added is 3% of the mass of the organic phase.

[0047] Dosage of sulfuric acid solution: Determined by stripping A / O. When stripping vanadium, the amount of reducing agent is based on the weight of the oil phase, or can also be expressed according to the theoretical excess coefficient, and the amount of sulfuric acid is determined according to the sulfuric acid concentration and the stripping A / O ratio.

[0048] The concentration of the sulfuric acid solution is 0.1-6M, preferably, the concentration of the sulfuric acid solution is 3M.

[0049] The stripping conditions are: multi-stage countercurrent stripping at 20-30° C., stripping time of 3-10 min, and stripping O / A=(10-1):1.

[0050] Preferably, the stripping conditions are: multi-stage countercurrent stripping at 25° C., stripping time of 5 min, and O / A=3:1 after stripping.

[0051] In step 4, the conditions for stripping molybdenum are: adding sodium carbonate solution or ammonia water to strip molybdenum at 20-30° C., the stripping time is 3-10 min, and the stripping O / A = (20-1):1.

[0052] Preferably, the conditions for stripping molybdenum are: adding sodium carbonate solution to strip molybdenum at 25° C., the stripping time is 5 min, and O / A after stripping is 3:1.

[0053] The stripping agent obtained after stripping can also be recycled to step 2 for extraction, which saves energy, reduces emissions and is environmentally friendly.

[0054] Example The present invention is further described below by means of specific examples. These embodiments are only intended to illustrate the present invention but are not intended to limit the scope of the present invention.

[0055] Example 1 Step 1: The waste oil hydrogenation catalyst is subjected to an oxidation roasting at a temperature of 550°C and a roasting time of 5h; then mixed with a 30wt% soda ash (Na2CO3) solution to form a loose gravel state, and the molar ratio of soda ash to (V2O5+MoO3) in the waste oil hydrogenation catalyst after oxidation roasting is 2.5:1, then dried at 120°C for 1.5h, and then subjected to a secondary sodium roasting at a temperature of 550°C and a roasting time of 6h; clean water is added to the sodium roasting material, the mass ratio of the sodium roasting material to water is 1:4, the leaching temperature is 75°C, the leaching time is 2.5h, and the vanadium-molybdenum leaching solution is obtained by leaching. The vanadium-molybdenum leaching solution mainly contains sodium vanadate, sodium molybdate and sodium carbonate, with a pH of 10.

[0056] Step 2: Filter and wash the vanadium-molybdenum leaching solution obtained in step 1 using a vacuum filter, and then adjust the pH value of the solution to 2.0 with sulfuric acid.

[0057] At 25°C, the extraction system was saponified with 32wt% sodium carbonate solution, with a saponification rate of 70%; the saponified extraction system was added while stirring, and the extractant, modifier and diluent were added at the same time, stirred evenly, and extracted at room temperature (25°C), and multi-stage countercurrent extraction was performed for 5 minutes to obtain an organic phase and an aqueous phase, O / A (volume ratio of organic phase / aqueous phase) = 1:3. Among them, the volume ratio of the extractant TOA, the modifier octanol and the diluent kerosene was 20:5:70.

[0058] Step 3: Wash the organic phase obtained by extraction, and then use 2.0 mol / L sulfuric acid solution + reducing agent to strip vanadium. The amount of reducing agent added is 3% of the mass of the organic phase. Multi-stage countercurrent stripping is carried out at room temperature (25°C). The stripping time is 5 minutes. The reducing agent is SO2. After stripping, O / A=3:1. Vanadyl sulfate solution is obtained by stripping.

[0059] Step 4: Wash the organic phase after stripping vanadium, and then strip molybdenum with 2 mol / L sodium carbonate solution, O / A=3:1, and perform multi-stage countercurrent stripping at room temperature (25°C). The stripping time is 5 minutes to obtain a molybdenum-containing solution.

[0060] Example 2 Step 1: The waste oil hydrogenation catalyst is subjected to an oxidation roasting at a temperature of 500°C and a roasting time of 8 hours; then mixed with a 30wt% soda ash (Na2CO3) solution to form a loose gravel state, the molar ratio of soda ash to (V2O5+MoO3) in the waste oil hydrogenation catalyst after oxidation roasting is 4:1, then dried at 110°C for 2 hours, and then subjected to a secondary sodium roasting at a temperature of 500°C and a roasting time of 8 hours; clean water is added to the sodium roasting material, the mass ratio of the sodium roasting material to water is 1:2.5, the leaching temperature is 60°C, the leaching time is 4 hours, and a vanadium-molybdenum leaching solution is obtained by leaching. The leaching solution is mainly sodium vanadate, sodium molybdate and sodium carbonate, with a pH of 9.

[0061] Step 2: Filter and wash the vanadium-molybdenum leaching solution obtained in step 1 using a vacuum filter, and then adjust the pH value of the solution to 1.5 with sulfuric acid.

[0062] At 20°C, the extraction system was saponified with 30wt% ammonia water, with a saponification rate of 60%; the saponified extraction system was added while stirring, and the extractant, modifier and diluent were added at the same time, stirred evenly, and extracted at room temperature (20°C), and multi-stage countercurrent extraction was performed for 10 minutes to obtain an organic phase and an aqueous phase, O / A (volume ratio of organic phase / aqueous phase) = 1:1. Among them, the volume ratio of the extractant N235, the modifier isooctyl alcohol and the diluent kerosene was 10:10:60.

[0063] Step 3: Wash the organic phase obtained by extraction, and then use 1.0 mol / L sulfuric acid solution + reducing agent to strip vanadium. The amount of reducing agent added is 0.5% of the mass of the organic phase. Multi-stage countercurrent stripping is carried out at room temperature (20°C). The stripping time is 10 minutes. The reducing agent is sodium thiosulfate. After stripping, O / A=4:1, and stripping obtains vanadium sulfate solution.

[0064] Step 4: Wash the organic phase after stripping vanadium, and then strip molybdenum with aqueous ammonia, O / A=4:1, and perform multi-stage countercurrent stripping at room temperature (20°C), the stripping time is 10 minutes, and a molybdenum-containing solution is obtained. Example 3 Step 1: The waste oil hydrogenation catalyst is subjected to an oxidation roasting at a temperature of 600°C and a roasting time of 3 hours; then mixed with a 30wt% soda ash (Na2CO3) solution to form a loose gravel state, and the molar ratio of soda ash to (V2O5+MoO3) in the waste oil hydrogenation catalyst after oxidation roasting is 1.05:1, then dried at 130°C for 1 hour, and then subjected to a secondary sodium roasting at a temperature of 600°C and a roasting time of 3 hours; clean water is added to the sodium roasting material, the mass ratio of the sodium roasting material to water is 1:5, the leaching temperature is 90°C, the leaching time is 1 hour, and the vanadium-molybdenum leaching solution is obtained by leaching. The vanadium-molybdenum leaching solution mainly contains sodium vanadate, sodium molybdate and sodium carbonate, with a pH of 11.

[0065] Step 2: Filter and wash the vanadium-molybdenum leaching solution obtained in step 1 using a vacuum filter, and then adjust the pH value of the solution to 2.2 with sulfuric acid.

[0066] At 30°C, the extraction system was saponified with 32wt% soda ash solution, with a saponification rate of 80%; the saponified extraction system was added while stirring, and the extractant, modifier and diluent were added at the same time, stirred evenly, and extracted at room temperature (30°C), and multi-stage countercurrent extraction was performed for 3 minutes to obtain an organic phase and an aqueous phase, O / A (volume ratio of organic phase / aqueous phase) = 1:4. Among them, the volume ratio of the extractant N263, the modifier octanol and the diluent kerosene was 30:10:80.

[0067] Step 3: Wash the organic phase obtained by extraction, and then use 3.0 mol / L sulfuric acid solution + reducing agent to strip vanadium. The amount of reducing agent added is 5% of the mass of the organic phase. Multi-stage countercurrent stripping is carried out at room temperature (30°C). The stripping time is 3 minutes. The reducing agent is sodium metabisulfite. After stripping, O / A=1:1, and stripping obtains vanadium sulfate solution.

[0068] Step 4: Wash the organic phase after stripping vanadium, and then strip molybdenum with 1.0 mol / L sodium carbonate solution, O / A=1:1, and perform multi-stage countercurrent stripping at room temperature (30°C). The stripping time is 3 minutes to obtain a molybdenum-containing solution. Experimental example Experimental Example 1 Component Test The components of the calcined materials after the primary oxidation calcination of Example 1, Example 2 and Example 3 were tested respectively, and the test results are shown in Table 1. The components of the vanadium-containing molybdenum leaching solution of Example 1 were tested, and the test results are shown in Table 2.

[0069] Table 1 Composition of waste oil hydrogenation catalyst after primary calcination

[0070] Note: The “%” in Table 1 refers to mass percentage.

[0071] Table 2 Leachate composition list

[0072] As can be seen from Table 1, after the first roasting, the main components of the roasting material except Al2O3 are V2O5 and MoO3. As can be seen from Table 2, after leaching with water, the main components of the leachate except Al and Na are Mo and V, and the content of other elements is small, indicating that the leachate obtained by the method of the present invention has fewer impurities and can be removed by chemical precipitation, indicating that a high-purity vanadium sulfate solution can be obtained by this method.

[0073] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a vanadyl sulfate electrolyte using a waste oil hydrogenation catalyst, characterized in that: The method comprises the following steps: Step 1, oxidatively roasting the waste oil hydrogenation catalyst, then adding soda ash, mixing and drying, then sodium roasting, adding water to the sodium roasted material for leaching, and obtaining a vanadium-molybdenum leaching solution; Step 2, filtering and washing the vanadium-molybdenum-containing leachate, then adding acid to adjust the pH, then adding alkali for saponification, and extracting the saponified leachate to obtain an organic phase and an aqueous phase; Step 3, washing the organic phase, and then adding a sulfuric acid solution and a reducing agent for stripping to obtain a vanadyl sulfate solution; Step 4: Wash the organic phase after stripping, then add alkali to strip molybdenum to obtain a molybdenum-containing solution.

2. The method according to claim 1, characterized in that In step 1, The oxidation roasting conditions are: the oxidation roasting temperature is 400-800° C., and the oxidation roasting time is 3-8 hours.

3. The method according to claim 1, characterized in that In step 1, The molar ratio of soda ash to the oxidatively calcined waste oil hydrogenation catalyst is (1.05-4):1, and the molar number of the oxidatively calcined waste oil hydrogenation catalyst is the sum of the molar numbers of V2O5 and MoO3.

4. The method according to claim 1, characterized in that: In step 1, The conditions of the sodium calcination are as follows: the sodium calcination temperature is 400-800° C., and the sodium calcination time is 3-8 hours.

5. The method according to claim 1, characterized in that: In step 1, The water leaching conditions are as follows: the mass ratio of the sodium roasted material to water is 1:(2.5-5), the leaching temperature is 40-90° C., and the leaching time is 1-4 hours.

6. The method according to claim 1, characterized in that In step 2, After filtering and washing, sulfuric acid is added to adjust the pH of the vanadium-molybdenum leaching solution to 1.5-2.2; The saponification conditions are: adding a soda solution or ammonia water for saponification at 20-30° C., and the saponification rate is 0-80%.

7. The method according to claim 1, characterized in that In step 2, The extraction conditions are: adding an extractant, a modifier and a diluent, performing multi-stage countercurrent extraction at 20-30° C., an extraction time of 3-10 minutes, and extraction O / A=1:(1-10).

8. The method according to claim 1, characterized in that In step 3, The reducing agent is selected from one or more of SO2, H2, sodium sulfite, sodium bisulfite, sodium thiosulfate, and sodium pyrosulfite; The amount of the reducing agent added is 0.5% to 5% of the mass of the organic phase.

9. The method according to claim 1, characterized in that: In step 3, The stripping conditions are: multi-stage countercurrent stripping at 20-30° C., stripping time of 3-10 min, and stripping O / A=(10-1):

1.

10. The method according to claim 1, characterized in that In step 4, The conditions for stripping molybdenum are: adding sodium carbonate solution or ammonia water to strip molybdenum at 20-30° C., the stripping time is 3-10 minutes, and the stripping O / A=(20-1):1.

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