A high-efficiency co-extraction device and method for vanadium and chromium from vanadium slag

Abstract

This invention discloses a device and method for efficient co-extraction of vanadium and chromium from vanadium slag, comprising a mixing tank, a slurry pump, a slurry processor, a slurry distributor, a heater, and a reactor connected in sequence. The slurry processor includes a cavity, a slurry inlet, a guide vane ring, a power nozzle, an air intake pipe, and a diffusion chamber nozzle. The cavity, from front to back, consists of a buffer chamber, a mixing chamber, and a diffusion chamber. The slurry inlet is located in the buffer chamber, and the air intake pipe is inserted into the mixing chamber. The guide vane ring and the power nozzle are connected from front to back and located between the buffer chamber and the mixing chamber, while the diffusion chamber nozzle is located between the mixing chamber and the diffusion chamber. The slurry pump is connected to the slurry inlet, the slurry distributor is connected to the diffusion chamber, and the air intake pipe is connected to a high-temperature air source. This invention's device and method achieve efficient co-extraction of vanadium and chromium at low temperature and under normal pressure, with a vanadium leaching rate of over 98% and a chromium leaching rate of over 95%.

Description

Technical Field

[0001] This invention relates to a vanadium-chromium extraction technology, and more particularly to a highly efficient co-extraction device and method for vanadium-chromium from vanadium slag. Background Technology

[0002] Vanadium is an important rare metal element widely used in steel, chemical, defense, electronics, manufacturing, energy storage, pharmaceutical, and catalysis industries. However, vanadium ore often contains chromium, and the two have similar physicochemical properties, making separation extremely difficult. In hydrometallurgy and other fields, valuable components are typically extracted from large quantities of minerals through gas-liquid-solid three-phase reactions. The resource utilization of vanadium-chromium ore slag, especially high-chromium slag, has always been a major obstacle to the development of the vanadium industry. Despite numerous attempts by researchers, satisfactory results have not yet been achieved.

[0003] CN114854988A discloses a method for selectively separating vanadium and chromium from vanadium-chromium materials using CO2. This method utilizes the selective oxidation of vanadium in vanadium-chromium raw materials by carbon dioxide to achieve vanadium-chromium separation. The specific steps are: mixing the vanadium-chromium material with carbonates, pressing it into briquettes, placing it in a vertical furnace, calcining it with carbon dioxide, cooling, crushing, and dissolving it to obtain a vanadium-containing solution and a chromium-containing residue. The vanadium-containing solution is used to recover vanadium by precipitation, and the chromium-containing residue is used to prepare chromium alloys. However, in this method, vanadium is oxidized along with some chromium, and the oxidized chromium enters the product and wastewater, not only reducing product quality but also increasing the difficulty of wastewater treatment. Therefore, this method also results in high ammonia nitrogen and high sulfur wastewater, as well as ammonia-containing tail gas.

[0004] CN109207728A discloses a method for extracting chromium and vanadium from chromium-vanadium slag using a high-temperature roasting process. This method employs a mixture of calcium and sodium salts as additives during the roasting process to convert vanadium in the slag into calcium vanadate and chromium into sodium chromate. The roasted clinker is then leached with water to obtain a chromium-containing leachate and vanadium-rich clinker. The vanadium-rich clinker is then leached with ammonium or sodium salt solutions to obtain a vanadium-containing leachate and waste residue. However, due to the uncontrollable nature of the reaction, this method may also produce sodium vanadate during roasting, resulting in low vanadium-chromium separation efficiency.

[0005] Currently, most vanadium-chromium co-extraction methods employ high temperature and high pressure with direct oxygen extraction. However, the contact surface area between the gas and liquid is small, and the rapid rise of large bubbles in the liquid results in a short residence time. This short contact time hinders effective reaction and fails to achieve the desired dissolved gas effect. Therefore, the industry urgently needs to develop a highly efficient vanadium-chromium co-extraction device and method to address issues such as ammonia nitrogen wastewater and waste gas generation. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an efficient co-extraction device for vanadium and chromium from vanadium slag with good extraction effect; the present invention also provides an efficient co-extraction method for vanadium and chromium from vanadium slag.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the device of the present invention is as follows: it includes a mixing tank, a slurry delivery pump, a slurry processor, a slurry distributor, a heater, and a reactor connected in sequence; the slurry processor includes a cavity, a slurry inlet, a guide vane ring, a power nozzle, an air intake pipe, and a diffusion chamber nozzle; the cavity is arranged from front to back as a buffer cavity, a mixing cavity, and a diffusion cavity; the slurry inlet is located in the buffer cavity, and the air intake pipe is inserted into the mixing cavity; the guide vane ring and the power nozzle are connected from front to back and located between the buffer cavity and the mixing cavity, and the diffusion chamber nozzle is located between the mixing cavity and the diffusion cavity; the slurry delivery pump is connected to the slurry inlet, the slurry distributor is connected to the diffusion cavity, and the air intake pipe is connected to a high-temperature air source.

[0008] Furthermore, the heater includes a shell and several slurry pipes located inside the shell; the front end of the slurry pipes is connected to a slurry distributor and the rear end is connected to a reactor; the shell is connected to a high-temperature medium pipeline.

[0009] Furthermore, the air intake tube is inserted from top to bottom into the lower part of the mixing chamber.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: using the above-mentioned co-extraction device, including the following steps: 1) mixing vanadium slag, sodium hydroxide and water in a mixing tank to form a slurry, and then sending it to the slurry processor by a slurry conveying pump;

[0011] 2) The slurry fed into the slurry processor enters the buffer chamber, and is sprayed into the mixing chamber through the guide vane ring and the power nozzle, which creates a negative pressure in the mixing chamber. Under the action of the negative pressure, the air intake pipe draws in high-temperature air to achieve gas-liquid-solid three-phase mixing; the three-phase mixed slurry is sprayed into the diffusion chamber through the diffusion chamber nozzle.

[0012] 3) The three-phase mixed slurry is then heated by a slurry distributor and then enters the reactor for reaction. After the reaction, the solid and liquid are separated to obtain vanadium-chromium leaching solution.

[0013] Furthermore, in step 1), vanadium slag, sodium hydroxide, and water are mixed in a mass ratio of 1:1.8-2.4:3-4.

[0014] Furthermore, in step 1), the particle size of the vanadium slag is 18–150 μm.

[0015] Furthermore, in step 2), the high-temperature air temperature is 140–180°C.

[0016] Furthermore, in step 1), the slurry flow rate pumped into the slurry processor by the slurry delivery pump is 1–10 m³ / s. 3 / h; In step 2), the flow rate of high-temperature air drawn in through the air intake pipe is 5 to 200 L / h.

[0017] Furthermore, in step 3), the reaction temperature in the reactor is controlled at 140–160°C, and the reaction time is 2–4 hours.

[0018] The beneficial effects of adopting the above technical solution are as follows: The device of the present invention realizes a high-efficiency gas-liquid-solid three-phase reaction through a slurry processor, effectively solving the problems of low oxygen transfer efficiency and difficulty in vanadium-chromium co-extraction due to high alkalinity in the vanadium extraction process of alkaline media, and realizing high-efficiency co-extraction of vanadium and chromium at low temperature under normal pressure, wherein the vanadium leaching rate reaches more than 98% and the chromium leaching rate reaches more than 95%.

[0019] The method of this invention increases the contact surface area between gas and liquid through a slurry processor, improving the dissolved oxygen rate by more than 35% and resulting in a more complete reaction; it achieves efficient co-extraction of vanadium and chromium at low temperature under normal pressure, with vanadium leaching rate exceeding 98% and chromium leaching rate exceeding 95%; compared with the traditional sodium roasting process, the liquid-solid ratio is reduced by more than 30%, the reaction temperature is reduced from 850℃ to below 200℃, and the reaction time is shortened; and no waste is generated during the production process compared with the traditional process. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is a schematic diagram of the structure of the device of the present invention.

[0022] In the diagram: 1. Mixing tank; 2. Slurry pump; 3. Slurry inlet; 4. Buffer chamber; 5. Guide vane ring; 6. Power nozzle; 7. Air intake pipe; 8. Mixing chamber; 9. Diffusion chamber nozzle; 10. Diffusion chamber; 11. Slurry processor; 12. Slurry distributor; 13. Heater; 14. Reactor. Detailed Implementation

[0023] Figure 1As shown, the high-efficiency co-extraction device for vanadium and chromium in vanadium slag includes a mixing tank 1, a slurry delivery pump 2, a slurry processor 11, a slurry distributor 12, a heater 13, and a reactor 14 connected in sequence. The slurry processor 11 includes a cavity, a slurry inlet 3, a guide vane ring 5, a power nozzle 6, an air intake pipe 7, and a diffusion chamber nozzle 9. The cavity, from front to back, consists of a buffer chamber 4, a mixing chamber 8, and a diffusion chamber 10. The slurry inlet 3 is located in the buffer chamber 4, and the mixing tank 1 is connected to the slurry inlet 3 via the slurry delivery pump 2. The air intake pipe 7 is inserted from top to bottom into the lower part of the mixing chamber 8 from the middle of its front and rear sides, preferably 10-25 cm from the bottom of the mixing chamber 8; one end of the air intake pipe 7 is connected to a high-temperature air source. The guide vane ring 5 and the power nozzle 6 are connected in sequence from front to back and are located between the buffer chamber 4 and the mixing chamber 8, separating the buffer chamber 4 and the mixing chamber 8 into two cavities. The guide vane ring 5 includes guide vane ring blades and a motor, which drives the guide vane ring blades to rotate. The inlet angle of each guide vane ring blade is smaller than its own outlet angle, and the rotating guide vane ring blades can drive the slurry to flow backward. Preferably, the inlet angle of the guide vane ring blades is between 2° and 7°, and the outlet angle is between 40° and 50°. It is preferable to have six guide vane ring blades. This structure of the guide vane ring blades realizes the swirling jet of the circulating liquid and increases the mass transfer efficiency. The diffuser nozzle 9 is located between the mixing chamber 8 and the diffuser chamber 10, separating the mixing chamber 8 and the diffuser chamber 10 into two cavities. The slurry distributor 12 is connected to the rear end of the diffuser chamber 10. With this structure, the raw materials are mixed into a slurry in the mixing tank 1, and then sent to the slurry inlet 3 of the slurry processor 11 by the slurry delivery pump 2. The slurry enters the buffer chamber 4, and is sprayed into the mixing chamber 8 through the guide vane ring 5 and the power nozzle 6, which creates a negative pressure in the mixing chamber 8. Under the action of the negative pressure, the air intake pipe 7 draws in high-temperature air from the high-temperature air source, and the gas-liquid-solid three-phase mixing is realized in the mixing chamber 8. The three-phase mixed slurry is sprayed into the diffusion chamber 10 through the diffusion chamber nozzle 9, and then enters the slurry distributor 12.

[0024] Figure 1 As shown, the heater 13 of this high-efficiency co-extraction device for vanadium and chromium in vanadium slag includes a cylinder and several slurry pipes located inside the shell; the number of slurry pipes is preferably [number missing]; the front end of each slurry pipe is connected to a slurry distributor 12, and the rear end is connected to a reactor 14; the cylinder is provided with an air inlet and an air outlet, the air inlet being connected to a high-temperature medium pipeline, and the air outlet being returned to the high-temperature medium pipeline; the high-temperature medium pipeline is preferably a steam pipeline. With this structure, the three-phase mixed slurry enters the slurry pipe of the heater 13 through the slurry distributor 12, and the high-temperature medium pipeline circulates the high-temperature medium between the cylinder and the slurry pipe of the heater 13 through the air inlet and the air outlet, using the high-temperature medium to heat the three-phase mixed slurry.

[0025] Figure 1As shown, the efficient co-extraction method for vanadium and chromium from vanadium slag, using the aforementioned co-extraction device, includes the following steps: 1) Mixing vanadium slag, sodium hydroxide, and water in a mixing tank 1 to form a slurry, and then feeding it into a slurry processor 11 via a slurry pump 2 and slurry inlet 3. The mass ratio of vanadium slag, sodium hydroxide, and water is 1:1.8–2.4:3–4, preferably controlling the mass ratio of water to solid materials to be 1.0–1.2:1. The particle size of the vanadium slag is 18–150 μm, preferably 25–106 μm, and more preferably 38–53 μm. The slurry flow rate fed into the slurry processor 11 by the slurry pump 2 is controlled to be 1–10 m³ / s. 3 / h, preferably 3-8m 3 / h, more preferably 5-6m 3 / h;

[0026] 2) The slurry enters the buffer chamber 4 of the slurry processor 11, and is sprayed into the mixing chamber 8 through the guide vane ring 5 and the power nozzle 6, creating a negative pressure in the mixing chamber 8. Under the action of the negative pressure, the air intake pipe 7 draws in high-temperature air from the high-temperature air source, realizing the three-phase mixing of gas, liquid, and solid. The resulting three-phase mixed slurry is sprayed into the diffusion chamber 10 through the diffusion chamber nozzle 9. The temperature of the high-temperature air is 140-180℃; the flow rate of the high-temperature air drawn into the mixing chamber 8 is 5-200 L / h, preferably 30-140 L / h, and more preferably 60-110 L / h.

[0027] 3) The three-phase mixed slurry is then heated by the slurry distributor 12 into the heater 13. The heated three-phase mixed slurry then enters the reactor 14 for reaction. After the reaction, solid-liquid separation is performed to obtain vanadium-chromium leaching solution. The heater 13 is heated by steam, with the steam pressure controlled at 1.2 MPa to 1.5 MPa. The reaction temperature in the reactor 14 is controlled at 140 to 160°C, and the reaction time is 2 to 4 hours.

[0028] Example 1: The following specific process is used for the efficient co-extraction of vanadium and chromium from vanadium slag.

[0029] 1) Mix 100 kg of vanadium slag with a diameter of 40 micrometers, 190 kg of sodium hydroxide, and 300 L of water in mixing tank 1.

[0030] 2) The slurry is pumped by a slurry delivery pump at a speed of 5m. 3 / h flow rate enters the buffer chamber 4 through the slurry inlet 3 of the slurry processor 11.

[0031] 3) The slurry in the buffer chamber 4 enters the mixing chamber 8 through the guide vane ring 5 and the power nozzle 6, creating a negative pressure zone in the mixing chamber. High-temperature air preheated to 180°C by the hot air furnace is delivered to the mixing chamber 8 at a flow rate of 110L / h through the air intake pipe 7 to achieve gas-liquid-solid three-phase mixing. The air outlet at the bottom of the air intake pipe 7 is 10cm away from the bottom of the mixing chamber.

[0032] 4) The three-phase mixture is injected into the diffusion chamber 10 through the nozzle 9 of the diffusion chamber;

[0033] 5) The slurry in the diffusion chamber 10 enters the 10 slurry pipes of the heater 13 through the slurry distributor 12. The outer cylinder of the heater 13 is heated by 1.5 MPa steam. The preheated slurry enters the reactor 14.

[0034] 6) The reaction temperature in reactor 14 was controlled at 160℃, and the reaction time was 4 hours. After the reaction, the slurry underwent solid-liquid separation, and the vanadium and chromium leaching rates in the tailings were measured by ICP to be 99.3 wt% and 96.8 wt%, respectively.

[0035] Example 2: The following specific process is used for the efficient co-extraction of vanadium and chromium from vanadium slag.

[0036] 1) Mix 100 kg of vanadium slag with a diameter of 45 micrometers, 185 kg of sodium hydroxide, and 300 L of water in mixing tank 1.

[0037] 2) The slurry is pumped by the slurry delivery pump 2 and enters the buffer chamber 4 through the slurry inlet 3 of the slurry processor 11 at a flow rate of 5.5 cubic meters per hour.

[0038] 3) The slurry in the buffer chamber 4 enters the mixing chamber 8 through the guide vane ring 5 and the power nozzle 6, creating a negative pressure zone in the mixing chamber. High-temperature air preheated to 170°C by the hot air furnace is delivered to the mixing chamber 8 at a flow rate of 90L / h through the air intake pipe 7 to achieve gas-liquid-solid three-phase mixing. The air outlet at the bottom of the air intake pipe 7 is 18cm away from the bottom of the mixing chamber 8.

[0039] 4) The three-phase mixture is injected into the diffusion chamber 10 through the nozzle 9 of the diffusion chamber;

[0040] 5) The slurry in the diffusion chamber 10 enters the 8 slurry pipes of the heater 13 through the slurry distributor 12. The outer cylinder of the heater 13 is heated by 1.3 MPa steam. The preheated slurry enters the reactor 14.

[0041] 6) The reaction temperature in reactor 14 was controlled at 155℃, and the reaction time was 3 hours. After the reaction, the slurry underwent solid-liquid separation, and the vanadium and chromium leaching rates in the tailings were measured by ICP to be 98.7% and 95.8%, respectively.

[0042] Example 3: The following specific process is used for the efficient co-extraction of vanadium and chromium from vanadium slag.

[0043] 1) Mix 100 kg of vanadium slag with a diameter of 52 micrometers, 180 kg of sodium hydroxide, and 300 L of water in mixing tank 1.

[0044] 2) The slurry is pumped by the slurry delivery pump 2 at a flow rate of 6 cubic meters per hour through the slurry inlet 3 of the slurry processor 11 and enters the buffer chamber 4.

[0045] 3) The slurry in the buffer chamber 4 enters the mixing chamber 8 through the guide vane ring 5 and the power nozzle 6, creating a negative pressure zone in the mixing chamber 8. High-temperature air preheated to 160°C by the hot air furnace is delivered to the mixing chamber 8 at a flow rate of 60L / h through the air intake pipe 7 to achieve gas-liquid-solid three-phase mixing. The bottom outlet of the air intake pipe 7 is 25cm away from the bottom of the mixing chamber 8.

[0046] 4) The three-phase mixture is injected into the diffusion chamber 10 through the nozzle 9 of the diffusion chamber;

[0047] 5) The slurry in the diffusion chamber 10 enters the 6 slurry pipes of the heater 13 through the slurry distributor 12. The outer cylinder of the heater 13 is heated by 1.2 MPa steam. The preheated slurry enters the reactor 14.

[0048] 6) The reaction temperature in reactor 14 was controlled at 140℃, and the reaction time was 2 hours. After the reaction, the slurry underwent solid-liquid separation, and the vanadium and chromium leaching rates in the tailings were measured by ICP to be 98.2% and 95.1%, respectively.

Claims

1. A method for efficient co-extraction of vanadium and chromium from vanadium slag, characterized in that, The co-extraction device includes a mixing tank (1), a slurry delivery pump (2), a slurry processor (11), a slurry distributor (12), a heater (13), and a reactor (14) connected in sequence. The slurry processor (11) includes a cavity, a slurry inlet (3), a guide vane ring (5), a power nozzle (6), an air intake pipe (7), and a diffusion chamber nozzle (9). The cavity consists of a buffer chamber (4), a mixing chamber (8), and a diffusion chamber (10) from front to back. The slurry inlet (3) is located in the buffer chamber (4), and the air intake pipe (7) is inserted into the mixing chamber (8). The air intake pipe (7) is inserted from top to bottom into the lower part of the mixing chamber (8), 10-25 cm from the bottom of the mixing chamber (8). One end of the air intake pipe (7) is connected to a high-temperature air source. The guide vane ring (5) and the power nozzle (6) are connected from front to back and are located in the buffer chamber (4) and the mixing chamber (9). Between the chambers (8), the buffer chamber (4) and the mixing chamber (8) are separated into two cavities; the guide vane ring (5) includes guide vane ring blades and a motor, the motor drives the guide vane ring blades to rotate; the inlet angle of the guide vane ring blades is smaller than its own outlet angle, the rotating guide vane ring blades can drive the slurry to flow backward; the inlet angle range of the guide vane ring blades is between 2° and 7°, the outlet angle range of the guide vane ring blades is between 40° and 50°, and six guide vane ring blades are provided; the guide vane ring (5) and the power nozzle (6) are connected from front to back and are located between the buffer chamber (4) and the mixing chamber (8), and the diffuser nozzle (9) is located between the mixing chamber (8) and the diffuser chamber (10); the slurry conveying pump (2) is connected to the slurry inlet (3), the slurry distributor (12) is connected to the diffuser chamber (10), and the air intake pipe (7) is connected to the high temperature air source; The process includes the following steps: 1) Mixing vanadium slag, sodium hydroxide and water in a mixing tank (1) to form a slurry, and then sending it to the slurry processor (11) via a slurry delivery pump (2). 2) The slurry fed into the slurry processor (11) enters the buffer chamber (4), and is sprayed into the mixing chamber (8) through the guide vane ring (5) and the power nozzle (6), which causes the mixing chamber (8) to generate negative pressure. Under the action of negative pressure, the air intake pipe (7) draws in high-temperature air to achieve gas-liquid-solid three-phase mixing; the three-phase mixed slurry is sprayed into the diffusion chamber (10) through the diffusion chamber nozzle (9); 3) The three-phase mixed slurry is then heated by the slurry distributor (12) and then enters the heater (13). The heated three-phase mixed slurry enters the reactor (14) for reaction. After the reaction, the solid and liquid are separated to obtain vanadium-chromium leaching solution.

2. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: The heater (13) includes a shell and several slurry pipes located inside the shell; the front end of the slurry pipes is connected to a slurry distributor (12) and the rear end is connected to a reactor (14); the shell is connected to a high-temperature medium pipeline.

3. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: The air intake tube (7) is inserted from top to bottom into the lower part of the mixing chamber (8).

4. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: In step 1), vanadium slag, sodium hydroxide, and water are mixed in a mass ratio of 1:1.8-2.4:3-4.

5. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: In step 1), the particle size of the vanadium slag is 18–150 μm.

6. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: In step 2), the high-temperature air temperature is 140–180°C.

7. The method for efficient co-extraction of vanadium and chromium from vanadium slag according to claim 1, characterized in that: In step 1), the slurry flow rate delivered by the slurry pump (2) to the slurry processor (11) is 1-10 m³ / h. 3 / h; in step 2), the air intake pipe (7) draws in high-temperature air at a flow rate of 5 to 200 L / h.

8. A method for efficient co-extraction of vanadium and chromium from vanadium slag according to any one of claims 1-7, characterized in that: In step 3), the reaction temperature in reactor (14) is controlled at 140-160°C and the reaction time is 2-4 hours.

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