A method for recovering valuable components from petrochemical waste residues

Abstract

The application discloses a method for recovering valuable components from petrochemical waste residues, and belongs to the field of resource recovery and chemical metallurgical technology, and comprises the following steps: step (A), high-pressure homogenization treatment; step (B), sulfuration reaction; step (C), oxidation and alkaline leaching; step (D), the obtained alkaline leaching residue in step (C) is subjected to acid leaching, and after solid-liquid separation, an acid leaching liquid containing nickel and an acid leaching residue mainly composed of carbon are obtained; step (E), vanadium precipitation and purification; step (F), the obtained vanadium precipitation tail liquid in step (E) is neutralized with acid, and the obtained solid is subjected to ultrasonic washing and drying to obtain molybdic acid; and step (G), the obtained acid leaching liquid in step (D) is purified and impurities are removed, and the obtained purified liquid is subjected to evaporation crystallization to obtain nickel sulfate. According to the process route of "high-pressure homogenization-no oxygen sulfuration-oxidation and alkaline leaching-acid leaching-step-by-step purification", the present application realizes efficient separation and high-value utilization of carbon resources and molybdenum, vanadium and nickel.

Description

Technical Field

[0001] This invention relates to the fields of resource recycling and chemical metallurgy, specifically a method for recovering valuable components from petrochemical waste. Background Technology

[0002] Petrochemical waste residue is a waste product generated during petroleum processing (such as catalytic cracking, hydrocracking, and catalytic reforming). Its composition is complex, mainly consisting of carbonaceous components (coke deposits, small amounts of hydrocarbons), catalyst residues (containing metallic elements such as molybdenum, vanadium, nickel, iron, and aluminum), and solid impurities. Improper disposal of this waste residue can not only cause serious soil and water pollution but also lead to a double waste of carbonaceous resources and valuable metals, violating the sustainable development concept of the metallurgical and chemical industries. Therefore, the resource recovery of petrochemical waste residue is of significant practical importance.

[0003] Currently, various recycling technologies have been developed in the industry for petrochemical waste containing molybdenum, vanadium, and nickel, but all have significant drawbacks: 1. Oxidative roasting method: This method removes carbonaceous components from the waste residue through high-temperature oxidative roasting (most of which are burned into carbon dioxide, with only low-value utilization), followed by sodium roasting and wet leaching to recover molybdenum and vanadium, and finally acid leaching to recover nickel. However, during roasting, molybdenum is easily lost as molybdenum trioxide, and after roasting, molybdenum, vanadium, and nickel easily form complex oxides, resulting in low subsequent leaching efficiency; at the same time, the flue gas generated by roasting causes secondary pollution. 2. Pyrometallurgical smelting method: As disclosed in Chinese patent CN117758069A, this method uses pyrometallurgical smelting to convert organic and inorganic impurities in the waste residue into glass slag, forming an alloy of molybdenum, vanadium, and nickel, followed by wet recovery of the metals in the alloy. However, this method has extremely low utilization of carbonaceous resources, and the resulting alloy has high hardness, making subsequent metal separation difficult and hindering the improvement of recovery rates. 3. Oxygen-Pressure Acid Leaching: As disclosed in Chinese Patent CN101713029A, this method uses oxygen-pressure acid leaching to first leach nickel and cobalt, and then recovers molybdenum and vanadium from the leaching residue. However, in this process, valuable metals are easily dispersed in different systems and are often carried over to each other, resulting in the purity of the final product (such as molybdenum salts, vanadium salts, and nickel salts) failing to meet industrial requirements. 4. Roasting-Alkali Leaching-Acid Leaching: As disclosed in Chinese Patents CN108018422A and CN119082501A, although stepwise leaching improves metal separation, it still relies on oxidative roasting pretreatment. This results in problems such as waste of carbonaceous resources, molybdenum volatilization loss, and difficulties in leaching composite oxides. The highest recovery rates for molybdenum and nickel are only 95% and 88%, respectively, and product purity still needs improvement.

[0004] In summary, existing technologies cannot simultaneously solve the four core problems of "waste of carbonaceous resources, environmental pollution, low recovery rate of valuable metals, and low product purity." There is an urgent need for an environmentally friendly, resource-efficient, and product-quality-compliant method for recycling petrochemical waste. Summary of the Invention

[0005] The purpose of this invention is to provide a method for recovering valuable components from petrochemical waste residue. Through a process route of "high-pressure homogenization-anaerobic sulfidation-oxidative alkaline leaching-acid leaching-stepwise purification", the method achieves efficient separation and high-value utilization of carbonaceous resources with molybdenum, vanadium, and nickel, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for recovering valuable components from petrochemical waste includes the following steps:

[0008] Step (A): Mix petrochemical waste residue with solvent and activator, and perform high-pressure homogenization treatment to obtain waste residue slurry;

[0009] Step (B): The waste residue slurry obtained in step (A) is mixed with a sulfiding reagent and subjected to a sulfidation reaction under an inert gas atmosphere. After the reaction is completed, the solid and liquid are separated to obtain the sulfidation product.

[0010] Step (C): The sulfide product obtained in step (B) is subjected to oxidative alkaline leaching in the presence of an oxidizing gas. After solid-liquid separation, an alkaline leaching solution containing molybdenum and vanadium and an alkaline leaching residue are obtained.

[0011] Step (D): The alkaline leaching residue obtained in step (C) is subjected to acid leaching. After solid-liquid separation, a nickel-containing acid leaching solution and an acid leaching residue whose main component is carbonaceous are obtained.

[0012] Step (E): Add ammonium salt to the alkaline leaching solution obtained in step (C) to carry out vanadium precipitation reaction. After solid-liquid separation, crude ammonium metavanadate and vanadium precipitation tail liquid are obtained. The crude ammonium metavanadate is centrifuged, washed and dried to obtain ammonium metavanadate.

[0013] Step (F): Neutralize the vanadium precipitate tailings obtained in step (E) with acid, and then wash and dry the resulting solid with ultrasonication to obtain molybdic acid;

[0014] Step (G): The acid leaching solution obtained in step (D) is purified to remove impurities. The purified solution is then evaporated and crystallized to obtain nickel sulfate.

[0015] As a further aspect of the present invention: in step (A), the solvent includes one or more of water, ethanol, acetone, glycerol, and dimethyl sulfoxide; the activator includes one or more of sodium polyacrylate, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sucrose ester, polysorbate, sucrose fatty acid ester, glycerol fatty acid ester, and sodium perfluorohexyl ethyl sulfonate; the mass ratio of the waste residue, solvent, and activator is 1:(3~10):(0.01~0.05); the conditions for the high-pressure homogenization treatment are: reaction time 0.5~3h, system pH value 3~6, ​​working pressure 10~50MPa, and flow rate 5~20L / min.

[0016] As a further embodiment of the present invention: in step (B), the inert gas is nitrogen or argon; the sulfiding reagent is one or more of sulfur, sodium sulfide, potassium sulfide, ammonium sulfide, sodium polysulfide, potassium polysulfide, sodium thiosulfate, sodium dithionite, potassium thiosulfate, potassium dithionite, thiourea, potassium thioacetate, and sodium thioacetate; the amount of the sulfiding reagent used is 1% to 10% of the mass of petrochemical waste residue; the conditions for the sulfidation reaction are: reaction temperature 150 to 300°C, reaction time 1 to 5 hours.

[0017] As a further embodiment of the present invention: in step (C), the oxidizing gas is oxygen or ozone; the alkaline reagent used in the oxidative alkaline leaching includes one or more of sodium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide, and sodium bicarbonate, and its amount is 2% to 10% of the mass of petrochemical waste residue; the conditions for the oxidative alkaline leaching are: reaction temperature 70 to 95°C, reaction time 1 to 10 hours, and liquid-solid mass ratio of (1 to 3):1.

[0018] As a further embodiment of the present invention: in step (D), the acid reagent used for acid leaching is sulfuric acid, and its amount is 1% to 5% of the mass of petrochemical waste residue; the acid leaching conditions are: reaction temperature 20 to 80°C, reaction time 1 to 4 hours, and liquid-solid mass ratio of (1 to 3):1.

[0019] As a further embodiment of the present invention: in step (E), the ammonium salt includes one or more of ammonium acetate, ammonium chloride, ammonium sulfate, ammonium carbonate, and ammonium bicarbonate, and its amount is 1 to 3 times the molar amount of vanadium in the alkaline leaching solution; the vanadium precipitation reaction is carried out at room temperature for 1 to 3 hours; the washing solution used for centrifugal washing is a 3% (w / w) ammonium salt aqueous solution, the centrifugation speed is 600 to 3000 rpm, the single washing time is 3 to 10 minutes, and the number of washings is at least 3.

[0020] As a further embodiment of the present invention: in step (F), the acid reagent used for neutralization is nitric acid, the pH value at the neutralization endpoint is 0.5~1.2, the neutralization temperature is 40~80℃, and the neutralization reaction time is 1~3h; the conditions for ultrasonic washing are: the amount of pure water used in a single wash is 10~30 times the mass of the obtained molybdic acid, the washing time in a single wash is 10~30min, the ultrasonic power is 30~100W / L, and the ultrasonic frequency is 20~100kHz.

[0021] As a further aspect of the present invention: in step (G), the precipitant used for purification and impurity removal is one or more of calcium oxide, calcium sulfate, calcium carbonate, and calcium hydroxide; the conditions for purification and impurity removal are: adding a mixture of the precipitant and water at room temperature, wherein the mass ratio of the precipitant to water is 1:1, and adjusting the final pH value of the solution to 3-5.

[0022] As a further aspect of the present invention, the acid leaching residue obtained in step (D) is used as a raw material for preparing carbonaceous materials.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. High resource utilization and environmentally friendly: Abandoning the traditional oxidation roasting process, the carbonaceous components are opened to encapsulate the metal through high-pressure homogenization in step (A), and the carbonaceous acid leaching residue recovered in step (D) can be used to prepare high-value carbon materials. There is no loss of carbonaceous components or combustion pollution throughout the process; the process has no flue gas emissions and meets the requirements of green environmental protection.

[0025] 2. High recovery rate of valuable metals: Step (B) anaerobic sulfidation reaction can destroy the composite structure of molybdenum, vanadium and nickel oxides, so that molybdenum and vanadium are converted into easily leached sulfides, while nickel is retained in the solid phase; combined with step (C) oxidative alkaline leaching and step (D) acid leaching, the overall recovery rate of molybdenum, vanadium and nickel is greatly improved throughout the process.

[0026] 3. High product purity, meeting industrial standards: Through targeted purification processes (step E: centrifugal washing to remove impurities, step F: ultrasonic washing to remove impurities, and step G: calcium salt precipitation to remove impurities), the final ammonium metavanadate, molybdenum acid, and nickel sulfate are of high purity and can be used directly as industrial-grade raw materials, solving the problem of low product purity in existing technologies. Attached Figure Description

[0027] Figure 1 This is a flowchart of a method for recovering valuable components from petrochemical waste. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] As mentioned in the background section of this application, research has found that the carbonaceous resources in petrochemical waste residues in the prior art are underutilized or wasted, and pretreatment processes such as oxidative roasting cause environmental pollution; molybdenum, vanadium, and nickel are prone to forming composite oxides or alloys, resulting in low metal recovery rates; metals are easily carried over during separation, and the purity of products (such as ammonium metavanadate, molybdic acid, and nickel sulfate) cannot meet industrial standards, which has certain defects.

[0030] To address the aforementioned deficiencies, this application discloses a method for recovering valuable components from petrochemical waste residue. Through a process route of "high-pressure homogenization - anaerobic sulfidation - oxidative alkali leaching - acid leaching - stepwise purification", the method achieves efficient separation and high-value utilization of carbonaceous resources from molybdenum, vanadium, and nickel.

[0031] The following will describe in detail, with reference to the accompanying drawings, how the solution of this application solves the above-mentioned technical problems.

[0032] Please see Figure 1 In this embodiment of the invention, a method for recovering valuable components from petrochemical waste includes the following steps:

[0033] Step (A): High-pressure homogenization treatment;

[0034] Petrochemical waste residue is mixed with solvent and activator and subjected to high-pressure homogenization to obtain waste residue slurry;

[0035] Solvents include one or more of water, ethanol, acetone, glycerol, and dimethyl sulfoxide;

[0036] The active agents include one or more of sodium polyacrylate, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sucrose ester, polysorbate, sucrose fatty acid ester, glycerol fatty acid ester, and sodium perfluorohexyl ethyl sulfonate;

[0037] The mass ratio of petrochemical waste residue, solvent, and activator is 1:(3~10):(0.01~0.05);

[0038] High-pressure homogenization conditions: reaction time 0.5~3h, system pH 3~6, ​​working pressure 10~50MPa, flow rate 5~20L / min.

[0039] Step (B): Sulfidation reaction;

[0040] The waste residue slurry obtained in step (A) is mixed with a sulfiding reagent and subjected to a sulfidation reaction under an inert gas atmosphere. After the reaction is completed, the solid and liquid are separated to obtain the sulfidation product.

[0041] The inert gas is nitrogen or argon;

[0042] Sulfide reagents include one or more of the following: sulfur, sodium sulfide, potassium sulfide, ammonium sulfide, sodium polysulfide, potassium polysulfide, sodium thiosulfate, sodium dithionite, potassium thiosulfate, potassium dithionite, thiourea, potassium thioacetate, and sodium thioacetate.

[0043] The amount of sulfiding reagent used is 1% to 10% of the mass of petrochemical waste residue;

[0044] Vulcanization reaction conditions: reaction temperature 150~300℃, reaction time 1~5 hours.

[0045] Step (C): Oxidation and alkaline leaching;

[0046] The sulfidation product obtained in step (B) is subjected to oxidative alkaline leaching in the presence of an oxidizing gas. After solid-liquid separation, an alkaline leaching solution containing molybdenum and vanadium and an alkaline leaching residue are obtained.

[0047] The oxidizing gas is oxygen or ozone;

[0048] The alkaline reagents used in oxidative alkaline leaching include one or more of sodium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide, and sodium bicarbonate, and the amount used is 2% to 10% of the mass of petrochemical waste residue;

[0049] Oxidation-alkali leaching conditions: reaction temperature 70~95℃, reaction time 1~10 hours, liquid-solid mass ratio (1~3):1.

[0050] Step (D): Acid leaching;

[0051] The alkaline leaching residue obtained in step (C) is subjected to acid leaching. After solid-liquid separation, a nickel-containing acid leaching solution and an acid leaching residue whose main component is carbonaceous are obtained.

[0052] The acid used in acid leaching is sulfuric acid, and the dosage is 1% to 5% of the mass of petrochemical waste residue.

[0053] Acid leaching conditions: reaction temperature 20~80℃, reaction time 1~4 hours, liquid-solid mass ratio (1~3):1;

[0054] Acid leaching residue can be used as a raw material for preparing carbonaceous materials (such as activated carbon and carbon electrode materials).

[0055] Step (E): Vanadium precipitation and purification;

[0056] Ammonium salts were added to the alkaline leaching solution obtained in step (C) to carry out a vanadium precipitation reaction. After solid-liquid separation, crude ammonium metavanadate and vanadium precipitation tailings were obtained. The crude ammonium metavanadate was centrifuged, washed and dried to obtain ammonium metavanadate.

[0057] Ammonium salts include one or more of ammonium acetate, ammonium chloride, ammonium sulfate, ammonium carbonate, and ammonium bicarbonate, and the amount used is 1 to 3 times the molar amount of vanadium in the alkaline leaching solution;

[0058] Vanadium precipitation reaction conditions: carried out at room temperature, reaction time 1~3 hours;

[0059] Centrifugation washing conditions: The washing solution is a 3% ammonium salt aqueous solution, the centrifugation speed is 600~3000 rpm, the single washing time is 3~10 min, and the washing is performed at least 3 times.

[0060] Step (F): Molybdenum precipitation and purification;

[0061] The vanadium tailings obtained in step (E) were neutralized with acid, and the resulting solid was ultrasonically washed and dried to obtain molybdic acid.

[0062] The acid reagent used for neutralization is nitric acid, the pH value at the neutralization endpoint is 0.5~1.2, the neutralization temperature is 40~80℃, and the neutralization reaction time is 1~3h;

[0063] Ultrasonic washing conditions: the amount of pure water used in a single wash is 10 to 30 times the mass of the obtained molybdic acid, the washing time is 10 to 30 minutes, the ultrasonic power is 30 to 100 W / L, and the ultrasonic frequency is 20 to 100 kHz.

[0064] Step (G): Nickel plating and purification;

[0065] The acid leaching solution obtained in step (D) is purified to remove impurities, and the purified solution is evaporated and crystallized to obtain nickel sulfate;

[0066] The precipitants used for purification and impurity removal include one or more of calcium oxide, calcium sulfate, calcium carbonate, and calcium hydroxide;

[0067] Purification and impurity removal conditions: Add a mixture of precipitant and water (precipitant to water mass ratio 1:1) at room temperature, and adjust the final pH value of the solution to 3~5.

[0068] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a method for recovering valuable components from petrochemical waste.

[0069] Example 1:

[0070] Step (A1) High-pressure homogenization treatment;

[0071] 1000g of petrochemical waste residue, 3000g of water, and 10g of sodium perfluorohexyl ethyl sulfonate were mixed and added to a high-pressure homogenizer. The reaction time was controlled at 3h, the pH value of the system was 6, the working pressure was 50MPa, and the flow rate was 5L / min. The waste residue slurry was obtained after the treatment.

[0072] Step (B1) Sulfidation reaction;

[0073] The waste residue slurry obtained in step (A1) was mixed with 100g of potassium dithionite and placed in a pressure vessel. Nitrogen (inert gas) was introduced and the reaction temperature was controlled at 150℃ for 5h. After the reaction was completed, the mixture was filtered to obtain 1024.20g of sulfide product (containing 4.22wt% molybdenum, 2.65wt% vanadium, and 1.35wt% nickel).

[0074] Step (C1) Oxidation and alkaline leaching;

[0075] The sulfidation product obtained in step (B1) was added to the reactor, oxygen (oxidizing gas) was introduced, and 100g of sodium hydroxide (alkali reagent) was added. The reaction temperature was controlled at 95℃, the reaction time at 1h, and the liquid-solid mass ratio at 3:1. After the reaction was completed, the solid and liquid were separated to obtain 3070mL of molybdenum-vanadium alkaline leaching solution (molybdenum concentration 14.02g / L, vanadium concentration 8.80g / L) and 867g of alkaline leaching residue.

[0076] Step (D1) Acid leaching;

[0077] Add 867g of alkaline leaching residue obtained in step (C1) to a reaction tank, add 10g of sulfuric acid (acid reagent), control the reaction temperature at 50℃, the reaction time at 2h, and the liquid-solid mass ratio at 3:1. After the reaction is completed, the solid and liquid are separated to obtain 2600mL of nickel-containing acid leaching solution (nickel concentration 5.30g / L) and 831.90g of carbonaceous acid leaching residue (which can be used to prepare carbon materials).

[0078] Step (E1) Vanadium precipitation and purification;

[0079] Add 30g of ammonium chloride (ammonium salt) to the 3070mL alkaline leaching solution obtained in step (C1), react at room temperature for 1h, and separate the solid and liquid to obtain crude ammonium metavanadate and vanadium precipitation tail liquid; wash the crude ammonium metavanadate with a 3% ammonium chloride aqueous solution, control the centrifugation speed at 600rpm and the washing time at 5min per wash, wash for a total of 5 times, and dry to obtain 61.89g of ammonium metavanadate (purity 99.59wt%).

[0080] Step (F1) Molybdenum precipitation and purification;

[0081] The vanadium precipitate tailings obtained in step (E1) were neutralized with nitric acid, and the neutralization endpoint pH was controlled at 0.5, the neutralization temperature at 45℃, and the reaction time at 3h to generate solid molybdic acid. The solid molybdic acid was ultrasonically washed with pure water, and the single pure water volume was controlled at 800mL, the ultrasonic power at 30W / L, the ultrasonic frequency at 100kHz, and the single washing time at 10min. After washing, it was dried to obtain 72.40g of molybdic acid (purity 99.62wt%).

[0082] Step (G1) Nickel immersion and purification;

[0083] Add a mixture of calcium oxide and water (calcium oxide:water = 1:1, mass ratio) to 2600 mL of nickel-containing acid leaching solution obtained in step (D1) at room temperature, adjust the final pH value of the solution to 3.5, filter to obtain purified solution; evaporate and crystallize the purified solution to obtain 36.10 g of nickel sulfate (purity 99.52 wt%).

[0084] Results data: Molybdenum leaching rate was 99.58% and vanadium leaching rate was 99.54% during alkaline leaching of sulfide products; nickel leaching rate was 99.66% during acid leaching of alkaline leaching residue; the overall molybdenum recovery rate was 99.26%, vanadium recovery rate was 99.41%, and nickel recovery rate was 99.01%; there was no loss of carbonaceous acid leaching residue.

[0085] Example 2:

[0086] Step (A2) High-pressure homogenization treatment;

[0087] Mix 1000g of petrochemical waste residue, 8000g of acetone, and 50g of fatty alcohol polyoxyethylene ether, add them to a high-pressure homogenizer, control the reaction time to 1h, the system pH value to 3, the working pressure to 10MPa, and the flow rate to 20L / min, and obtain waste residue slurry after processing.

[0088] Step (B2) Sulfation reaction;

[0089] The waste residue slurry obtained in step (A2) was mixed with 10g of sodium thiosulfate and placed in a pressure vessel. Argon gas (inert gas) was introduced and the reaction temperature was controlled at 300℃ and the reaction time was 1h. After the reaction was completed, the mixture was filtered to obtain 1011.73g of sulfide product (containing 4.43wt% molybdenum, 2.58wt% vanadium, and 1.42wt% nickel).

[0090] Step (C2) Oxidation and alkaline leaching;

[0091] The sulfidation product obtained in step (B2) was added to the reactor, ozone (oxidizing gas) was introduced, and 30g of sodium carbonate (alkali reagent) was added. The reaction temperature was controlled at 75℃, the reaction time at 9h, and the liquid-solid mass ratio at 1:1. After the reaction was completed, the solid and liquid were separated to obtain 1012mL of molybdenum-vanadium alkaline leaching solution (molybdenum concentration 44.21g / L, vanadium concentration 25.72g / L) and 859.85g of alkaline leaching residue.

[0092] Step (D2) Acid leaching;

[0093] Add 859.85g of alkaline leaching residue obtained in step (C2) to a reaction tank, add 50g of sulfuric acid (acid reagent), control the reaction temperature at 80℃, the reaction time at 4h, and the liquid-solid mass ratio at 1:1. After the reaction is completed, the solid and liquid are separated to obtain 860mL of nickel-containing acid leaching solution (nickel concentration 16.66g / L) and 823.02g of carbonaceous acid leaching residue.

[0094] Step (E2) Vanadium precipitation and purification;

[0095] Add 200g of ammonium sulfate (ammonium salt) to 1012mL of alkaline leaching solution obtained in step (C2), react at room temperature for 3h, and separate the solid and liquid to obtain crude ammonium metavanadate and vanadium precipitation tail liquid; wash the crude ammonium metavanadate with 3% ammonium sulfate aqueous solution, control the centrifugation speed at 3000rpm and the washing time at 10min per wash, wash for a total of 3 times, and dry to obtain 59.69g of ammonium metavanadate (purity 99.64wt%).

[0096] Step (F2) Molybdenum precipitation and purification;

[0097] The vanadium precipitate tailings obtained in step (E2) were neutralized with nitric acid, and the neutralization endpoint pH was controlled at 1.2, the neutralization temperature at 80℃, and the reaction time at 1 h to generate solid molybdic acid. The solid molybdic acid was ultrasonically washed with pure water, and the single pure water volume was controlled at 2000 mL, the ultrasonic power at 100 W / L, the ultrasonic frequency at 20 kHz, and the single washing time at 30 min. After washing, it was dried to obtain 75.14 g of molybdic acid (purity 99.68 wt%).

[0098] Step (G2) Nickel plating and purification;

[0099] Add a mixture of calcium carbonate and water (calcium carbonate: water = 1:1, mass ratio) to 860 mL of nickel-containing acid leaching solution obtained in step (D2) at room temperature, adjust the final pH value of the solution to 5, filter to obtain purified solution; evaporate and crystallize the purified solution to obtain 37.58 g of nickel sulfate (purity 99.57 wt%).

[0100] Results data: Molybdenum leaching rate was 99.82% and vanadium leaching rate was 99.72% during alkaline leaching of sulfide products; nickel leaching rate was 99.73% during acid leaching of alkaline leaching residue; the overall molybdenum recovery rate was 99.35%, vanadium recovery rate was 99.68%, and nickel recovery rate was 99.20%; there was no loss of carbonaceous acid leaching residue.

[0101] Example 3:

[0102] Step (A3) High-pressure homogenization treatment;

[0103] 1000g of petrochemical waste residue, 5000g of dimethyl sulfoxide, and 35g of sodium polyacrylate were mixed and added to a high-pressure homogenizer. The reaction time was controlled at 2h, the pH value of the system was 5, the working pressure was 30MPa, and the flow rate was 13L / min. The waste residue slurry was obtained after the treatment.

[0104] Step (B3) Sulfidation reaction;

[0105] The waste residue slurry obtained in step (A3) was mixed with 50g of ammonium sulfide and placed in a pressure vessel. Argon gas (inert gas) was introduced and the reaction temperature was controlled at 225℃ and the reaction time was 3h. After the reaction was completed, the mixture was filtered to obtain 1018.66g of sulfide product (containing 4.36wt% molybdenum, 2.71wt% vanadium, and 1.45wt% nickel).

[0106] Step (C3) Oxidation and alkaline leaching;

[0107] The sulfidation product obtained in step (B3) was added to the reactor, ozone (oxidizing gas) was introduced, and 50g of potassium hydroxide (alkali reagent) was added. The reaction temperature was controlled at 80℃, the reaction time at 5h, and the liquid-solid mass ratio at 2:1. After the reaction was completed, the solid and liquid were separated to obtain 2037mL of molybdenum-vanadium alkaline leaching solution (molybdenum concentration 21.74g / L, vanadium concentration 13.51g / L) and 863.02g of alkaline leaching residue.

[0108] Step (D3) Acid leaching;

[0109] Add 863.02g of alkaline leaching residue obtained in step (C3) to the reaction tank, add 30g of sulfuric acid (acid reagent), control the reaction temperature at 20℃, the reaction time at 2.5h, and the liquid-solid mass ratio at 2:1. After the reaction is completed, the solid and liquid are separated to obtain 1726mL of nickel-containing acid leaching solution (nickel concentration 8.53g / L) and 834.76g of carbonaceous acid leaching residue.

[0110] Step (E3) Vanadium precipitation and purification;

[0111] Add 200g of ammonium acetate (ammonium salt) to the 2037mL alkaline leaching solution obtained in step (C3), react at room temperature for 2h, and separate the solid and liquid to obtain crude ammonium metavanadate and vanadium precipitation tail liquid; wash the crude ammonium metavanadate with a 3% ammonium acetate aqueous solution, control the centrifugation speed at 1800rpm and the washing time at 6min per wash, wash for a total of 4 times, and dry to obtain 62.79g of ammonium metavanadate (purity 99.70wt%).

[0112] Step (F3) Molybdenum precipitation and purification;

[0113] The vanadium tailings obtained in step (E3) were neutralized with nitric acid, and the neutralization endpoint pH was controlled at 0.8, the neutralization temperature at 60℃, and the reaction time at 2h to generate solid molybdic acid. The solid molybdic acid was ultrasonically washed with pure water, and the single pure water volume was controlled at 1400mL, the ultrasonic power at 60W / L, the ultrasonic frequency at 60kHz, and the single washing time at 20min. After washing, it was dried to obtain 74.35g of molybdic acid (purity 99.55wt%).

[0114] Step (G3) Nickel plating and purification;

[0115] Add a mixture of calcium hydroxide and water (calcium hydroxide:water = 1:1, mass ratio) to 1726 mL of nickel-containing acid leaching solution obtained in step (D3) at room temperature, adjust the final pH value of the solution to 4, filter to obtain purified solution; evaporate and crystallize the purified solution to obtain 38.61 g of nickel sulfate (purity 99.59 wt%).

[0116] Results data: Molybdenum leaching rate was 99.71% and vanadium leaching rate was 99.69% during alkaline leaching of sulfide products; nickel leaching rate was 99.67% during acid leaching of alkaline leaching residue; the overall molybdenum recovery rate was 99.20%, vanadium recovery rate was 99.10%, and nickel recovery rate was 99.13%; there was no loss of carbonaceous acid leaching residue.

[0117] The above embodiments demonstrate that the method of the present invention can stably achieve high-value utilization of carbonaceous resources in petrochemical waste residue and efficient recovery of molybdenum, vanadium, and nickel. The product purity and metal recovery rate are significantly better than those of the prior art, and it has good prospects for industrial application.

[0118] This invention abandons the traditional oxidative roasting process. Step (A) involves high-pressure homogenization to break the metal encapsulation by the carbonaceous components. Step (D) utilizes the recovered carbonaceous acid leaching residue for the preparation of high-value carbon materials. The entire process involves no loss of carbonaceous components and no combustion pollution; the process emits no flue gas, meeting green environmental protection requirements. Furthermore, step (B) involves an anaerobic sulfidation reaction that breaks down the composite structure of molybdenum, vanadium, and nickel oxides, converting molybdenum and vanadium into easily leached sulfides, while nickel remains in the solid phase. Combined with step (C) oxidative alkaline leaching and step (D) acid leaching, the overall recovery rate of molybdenum, vanadium, and nickel is significantly improved. Simultaneously, through targeted purification processes (step E: centrifugal washing for impurity removal; step F: ultrasonic washing for impurity removal; step G: calcium salt precipitation for impurity removal), the final ammonium metavanadate, molybdic acid, and nickel sulfate are of high purity and can be directly used as industrial-grade raw materials, solving the problem of low purity in existing technologies.

[0119] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0120] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for recovering valuable components from petrochemical waste residue, characterized in that, Includes the following steps: Step (A): Mix petrochemical waste residue with solvent and activator, and perform high-pressure homogenization treatment to obtain waste residue slurry; Step (B): The waste residue slurry obtained in step (A) is mixed with a sulfiding reagent and subjected to a sulfidation reaction under an inert gas atmosphere. After the reaction is completed, the solid and liquid are separated to obtain the sulfidation product. Step (C): The sulfide product obtained in step (B) is subjected to oxidative alkaline leaching in the presence of an oxidizing gas. After solid-liquid separation, an alkaline leaching solution containing molybdenum and vanadium and an alkaline leaching residue are obtained. Step (D): The alkaline leaching residue obtained in step (C) is subjected to acid leaching. After solid-liquid separation, a nickel-containing acid leaching solution and an acid leaching residue whose main component is carbonaceous are obtained. Step (E): Add ammonium salt to the alkaline leaching solution obtained in step (C) to carry out vanadium precipitation reaction. After solid-liquid separation, crude ammonium metavanadate and vanadium precipitation tail liquid are obtained. The crude ammonium metavanadate is centrifuged, washed and dried to obtain ammonium metavanadate. Step (F): Neutralize the vanadium precipitate tailings obtained in step (E) with acid, and then wash and dry the resulting solid with ultrasonication to obtain molybdic acid; Step (G): The acid leaching solution obtained in step (D) is purified to remove impurities. The purified solution is then evaporated and crystallized to obtain nickel sulfate.

2. The method for recovering valuable components from petrochemical waste residue according to claim 1, characterized in that, In step (A), the solvent includes one or more of water, ethanol, acetone, glycerol, and dimethyl sulfoxide; the activator includes one or more of sodium polyacrylate, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sucrose ester, polysorbate, sucrose fatty acid ester, glycerol fatty acid ester, and sodium perfluorohexyl ethyl sulfonate; the mass ratio of the waste residue, solvent, and activator is 1:(3~10):(0.01~0.05); the conditions for the high-pressure homogenization treatment are: reaction time 0.5~3h, system pH value 3~6, ​​working pressure 10~50MPa, and flow rate 5~20L / min.

3. The method for recovering valuable components from petrochemical waste residue according to claim 1, characterized in that, In step (B), the inert gas is nitrogen or argon; the sulfiding reagent is one or more of sulfur, sodium sulfide, potassium sulfide, ammonium sulfide, sodium polysulfide, potassium polysulfide, sodium thiosulfate, sodium dithionite, potassium thiosulfate, potassium dithionite, thiourea, potassium thioacetate, and sodium thioacetate; the amount of the sulfiding reagent used is 1% to 10% of the mass of the petrochemical waste residue; the conditions for the sulfidation reaction are: reaction temperature 150 to 300°C, reaction time 1 to 5 hours.

4. The method for recovering valuable components from petrochemical waste residue according to claim 1, characterized in that, In step (C), the oxidizing gas is oxygen or ozone; the alkaline reagent used in the oxidative alkaline leaching includes one or more of sodium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide, and sodium bicarbonate, and its amount is 2% to 10% of the mass of petrochemical waste residue; the conditions for the oxidative alkaline leaching are: reaction temperature 70 to 95°C, reaction time 1 to 10 hours, and liquid-solid mass ratio of (1 to 3):

1.

5. The method for recovering valuable components from petrochemical waste residue according to claim 1, characterized in that, In step (D), the acid reagent used for acid leaching is sulfuric acid, and its amount is 1% to 5% of the mass of petrochemical waste residue; the acid leaching conditions are: reaction temperature 20 to 80°C, reaction time 1 to 4 hours, and liquid-solid mass ratio of (1 to 3):

1.

6. The method for recovering valuable components from petrochemical waste according to claim 1, characterized in that, In step (E), the ammonium salt includes one or more of ammonium acetate, ammonium chloride, ammonium sulfate, ammonium carbonate, and ammonium bicarbonate, and its amount is 1 to 3 times the molar amount of vanadium in the alkaline leaching solution; the vanadium precipitation reaction is carried out at room temperature for 1 to 3 hours; the washing solution used for centrifugal washing is a 3% (w / w) ammonium salt aqueous solution, the centrifugation speed is 600 to 3000 rpm, the single washing time is 3 to 10 minutes, and the number of washings is at least 3.

7. The method for recovering valuable components from petrochemical waste according to claim 1, characterized in that, In step (F), the acid used for neutralization is nitric acid, the neutralization endpoint pH is 0.5~1.2, the neutralization temperature is 40~80℃, and the neutralization reaction time is 1~3h. The conditions for ultrasonic washing are: the amount of pure water used in a single wash is 10~30 times the mass of the obtained molybdic acid, the washing time is 10~30min, the ultrasonic power is 30~100W / L, and the ultrasonic frequency is 20~100kHz.

8. The method for recovering valuable components from petrochemical waste according to claim 1, characterized in that, In step (G), the precipitant used for purification and impurity removal is one or more of calcium oxide, calcium sulfate, calcium carbonate, and calcium hydroxide; the conditions for purification and impurity removal are: adding a mixture of the precipitant and water at room temperature, wherein the mass ratio of the precipitant to water is 1:1, and adjusting the final pH value of the solution to 3-5.

9. A method for recovering valuable components from petrochemical waste according to claim 1, characterized in that, The acid leaching residue obtained in step (D) is used as a raw material for preparing carbonaceous materials.

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