Method and device for intensively leaching vanadium titano-magnetite concentrate

Abstract

The invention discloses a method and a device for intensively leaching vanadium titano-magnetite concentrate, and belongs to the technical field of metallurgy. The method is used for solving the problems that a large amount of high-concentration waste acid solution is generated due to the fact that concentrated acid needs to be adopted for reaction in existing vanadium titano-magnetite leaching; and low-concentration acid leaching cannot achieve an efficient leaching effect. The method comprises the following steps: grinding and screening the vanadium titano-magnetite concentrate; mixing the vanadium titano-magnetite concentrate with a sulfuric acid solution, and uniformly stirring to obtain mixed ore pulp; putting the mixed ore pulp into a device with a magnetic field, and carrying out leaching reaction; and after the leaching reaction is finished, reaction materials are filtered, and leaching liquid containing titanium, vanadium and iron is obtained. According to the method, elements such as titanium, iron and vanadium can be efficiently leached under the low-concentration acid condition, the efficiency is high, and the leaching effect is good.

Description

Technical Field

[0001] The present invention belongs to the field of metallurgy technology and specifically relates to a method and device for enhanced leaching of vanadium-titanium magnetite concentrate. Background Art

[0002] Vanadium-titanium magnetite is an important vanadium and titanium resource in my country. It is a complex mineral resource with vanadium, titanium and iron coexisting. The efficient utilization of metal resources such as vanadium, titanium and iron is a difficult problem in the industry. In the existing technology, the vanadium-titanium magnetite concentrate in Panzhihua area is currently mainly smelted through blast furnace smelting process. Through blast furnace reduction smelting, vanadium-containing molten iron and titanium-containing blast furnace slag are obtained. The vanadium-containing molten iron is further blown in a converter to obtain vanadium slag and molten steel. The vanadium slag is further processed to recover vanadium; this process can effectively realize the efficient utilization of vanadium and iron. At present, a lot of research and development work has been done around blast furnace ironmaking and vanadium slag extraction. However, during the blast furnace smelting process, almost all of the titanium and about 30% of the vanadium in the vanadium-titanium magnetite concentrate enter the blast furnace slag and cannot be effectively utilized. In addition, vanadium slag extraction mostly adopts the sodium / calcification process, which produces a large amount of vanadium extraction tailings solid waste. The vanadium-titanium magnetite in western Liaoning has the characteristics of high vanadium and titanium and low iron, and it is difficult to develop and utilize it using the traditional blast furnace-converter process.

[0003] In order to efficiently utilize the complex resource of multi-metal co-existence such as vanadium-titanium magnetite, the prior art has a method of using vanadium-titanium magnetite concentrate to obtain iron concentrate and mixed titanium middlings by magnetic separation after treatment with concentrated alkali solution, and obtain iron concentrate with an iron grade higher than 62% and a titanium grade lower than 4.5% and titanium middlings with a titanium grade higher than 35%; however, the recycling of titanium resources in the iron concentrate cannot be achieved; there is also a method of achieving effective separation of iron, vanadium and titanium by reduction roasting-water leaching-magnetic separation; CN109174398B discloses A method for obtaining titanium-vanadium-iron concentrate by multi-stage magnetic separation, and subjecting it to acid leaching-vanadium precipitation-hydrochloric acid leaching to prepare titanium-rich material. After multiple acid-base leaching, the comprehensive utilization of vanadium-titanium-iron can be achieved, but the process flow is long and multiple solid-liquid conversions are required. CN114480882A first extracts vanadium from vanadium-titanium magnetite concentrate by wet method and then extracts vanadium and iron respectively by melting reduction, then mixes titanium-containing molten slag with titanium concentrate for reduction and iron removal to obtain titanium slag, and then subjecting the titanium slag to alkali dissolution-water leaching-acid leaching to obtain titanium-rich material, and the process flow is long.

[0004] In summary, the efficient recovery of vanadium-titanium iron in vanadium-titanium magnetite concentrate currently mainly adopts blast furnace smelting treatment. The titanium component enters the blast furnace titanium slag and is difficult to extract, resulting in serious waste of titanium resources. The wet extraction method of sulfuric acid leaching requires concentrated sulfuric acid to react, producing a large amount of high-concentration waste acid solution. Low-concentration acid leaching cannot achieve efficient leaching effect. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for enhanced leaching of vanadium-titanium magnetite concentrate, which is used to solve one of the following technical problems: in the prior art, the leaching of vanadium-titanium magnetite requires the use of concentrated acid to react, producing a large amount of high-concentration waste acid solution; low-concentration acid leaching cannot achieve efficient leaching effects.

[0006] The above object of the present invention is achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, the method comprising the following steps:

[0008] Step 1: Grind and screen the vanadium-titanium magnetite concentrate;

[0009] Step 2: Mix the vanadium-titanium magnetite concentrate with the sulfuric acid solution, and stir evenly to obtain a mixed slurry;

[0010] Step 3: placing the mixed slurry into a device with a magnetic field to perform a leaching reaction;

[0011] Step 4: After the leaching reaction is completed, the reaction material is filtered to obtain a leaching solution containing titanium, vanadium and iron.

[0012] Furthermore, in step 3, the magnetic field adopts a pulsed magnetic field.

[0013] Furthermore, in step 3, the magnetic field strength of the pulsed magnetic field is 0.1 to 5 T, and the pulse interval is 1 to 10 s.

[0014] Furthermore, in step 2, the concentration of the sulfuric acid solution is 20% to 30%.

[0015] Furthermore, in step 2, the ratio of sulfuric acid solution to concentrate is 5 mL: 1 g to 15 mL: 1 g.

[0016] Furthermore, in step 3, the reaction temperature is 120-170°C.

[0017] The present invention also provides a vanadium-titanium magnetite concentrate enhanced leaching device, which is used to implement the above-mentioned vanadium-titanium magnetite concentrate enhanced leaching method. The vanadium-titanium magnetite concentrate enhanced leaching device includes a reaction device, a stirring device for stirring the material in the reaction device to provide centrifugal force and shear force, and a magnetic field generating device for providing a magnetic field.

[0018] Furthermore, the reaction device comprises a reactor, the reactor comprises a reactor body, a feed inlet and a discharge port are arranged on the reactor body, a heating jacket is arranged outside the reactor body, and a thermocouple for measuring the temperature of the material is arranged inside the reactor body.

[0019] Furthermore, the stirring device includes a magnetic stirrer, a stirring paddle, and a linkage shaft connecting the magnetic stirrer and the stirring paddle.

[0020] Furthermore, the magnetic field generating device includes a magnetic field coil and a magnetic field controller, and the magnetic field coil is arranged outside the heating sleeve.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] 1) The method for enhanced leaching of vanadium-titanium magnetite concentrate provided by the present invention utilizes the magnetism of the vanadium-titanium magnetite concentrate itself and adopts a magnetic field to achieve the dissolution of the vanadium-titanium magnetite concentrate under low acid concentration conditions, shorten the reaction time required for acid dissolution, and improve production efficiency.

[0023] 2) The method for strengthening leaching of vanadium-titanium magnetite concentrate provided by the present invention adopts a pulsed magnetic field, which is an intermittent magnetic field and has a more significant effect on the disorder of the crystal structure in magnetic minerals. Therefore, based on the mechanism of the influence of the pulsed magnetic field on the crystal structure of magnetic minerals, it is beneficial to enhance the mineral dissolution activity, and can effectively strengthen the leaching of vanadium-titanium magnetite in a low-concentration sulfuric acid solution to obtain a higher leaching rate.

[0024] 3) The method for enhanced leaching of vanadium-titanium magnetite concentrate provided by the present invention can achieve efficient leaching of elements such as titanium, iron, and vanadium under low-concentration acid conditions by precisely controlling process parameters such as magnetic field intensity, stirring speed, temperature, and acidity. It has high efficiency and good leaching effect and is suitable for large-scale application.

[0025] Other features and advantages of the present invention will be described in the following embodiments, and some of them can be obtained from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the contents particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are only for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. The same reference symbols denote the same contents throughout the accompanying drawings.

[0027] Figure 1 is a process flow chart of the method of the present invention;

[0028] Figure 2 It is a schematic diagram of the structure of the enhanced leaching device for vanadium-titanium magnetite concentrate.

[0029] Reference numerals:

[0030] 1-magnetic field coil; 2-1-reactor body, 2-2-thermocouple, 2-3-heating jacket, 2-4-feed port, 2-5-discharge port, 2-6-magnetic stirrer, 2-7-stirring paddle, 2-8-linkage shaft. DETAILED DESCRIPTION

[0031] Preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used to explain the principles of the present invention together with the embodiments of the present invention.

[0032] The present invention provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, which mainly comprises the following steps:

[0033] Step 1: Grinding and sieving the vanadium-titanium magnetite concentrate to obtain vanadium-titanium magnetite concentrate with a certain particle size range;

[0034] Step 2: Mix the vanadium-titanium magnetite concentrate and the sulfuric acid solution in a certain proportion, and stir evenly to obtain a mixed slurry;

[0035] Step 3: Place the mixed slurry into a device with a magnetic field and perform leaching reaction at a certain temperature;

[0036] Step 4: After the leaching reaction is completed, the reaction material is filtered to obtain a leaching solution containing titanium, vanadium and iron, and the leaching solution is used to recover the valuable components of titanium, iron and vanadium.

[0037] Specifically, in step 1, the mass percentages of some components in the vanadium-titanium magnetite concentrate are as follows: TFe>40%, TiO2>8%, V>0.1%. The vanadium-titanium magnetite concentrate below the 200-mesh sieve accounts for 95%;

[0038] Specifically, the above-mentioned vanadium-titanium magnetite concentrate is a concentrate obtained by beneficiation of vanadium-titanium magnetite in Panzhihua or western Liaoning and other regions.

[0039] Specifically, in step 1, the particle size range of the vanadium-titanium magnetite concentrate within a certain particle size range obtained after screening is: more than 90% of the particles are below the 200-mesh sieve.

[0040] Specifically, in step 2, the sulfuric acid concentration is too low, and the leaching reaction is incomplete; a high sulfuric acid concentration is easy to cause corrosion to the reaction container, and a large amount of high-concentration waste acid solution is subsequently generated, and the production cost is high; therefore, taking all factors into consideration, the concentration of the sulfuric acid solution is controlled to be 20% to 30%, and illustratively, the concentration of the sulfuric acid solution is 22%, 25%, and 28%.

[0041] Specifically, in step 2, when the ratio of sulfuric acid solution to concentrate is too large, the processing volume is limited and the acid reaction is incomplete; when the ratio of sulfuric acid solution to concentrate is small, it is difficult to mix the reaction materials and the reaction efficiency is low; therefore, taking all factors into consideration, the ratio of sulfuric acid solution to concentrate is controlled to be (5mL:1g) to (15mL:1g). Exemplarily, the ratio of sulfuric acid solution to concentrate is 7mL:1g, 10mL:1g, and 12mL:1g.

[0042] Specifically, considering that the interaction between the pulsed magnetic field and the mineral is intermittent, a resonance-like effect can be achieved by adjusting the magnetic field pulse frequency, resulting in more mineral lattice defects and improving leaching activity. Therefore, the magnetic field in step 3 uses a pulsed magnetic field.

[0043] Specifically, in step 3, the pulsed magnetic field is generated by an electromagnetic coil.

[0044] It should be noted that if the intensity of the pulsed magnetic field is too small, the enhanced leaching effect will not be obvious. If the intensity of the magnetic field is too large, the leaching effect will be limited, but the equipment manufacturing cost will increase exponentially. If the pulse time interval is too small or too large, it is difficult to enhance the leaching process of magnetic minerals, and a certain degree of matching with the magnetic substances in the minerals is required. Therefore, taking comprehensive considerations, the pulse interval is controlled to be 1 to 10 seconds and the magnetic field intensity is controlled to be 0.1 to 5T.

[0045] Specifically, in the above step 3, when the magnetic field strength is 0.1~<1T, the pulse interval is 1~3s; when the magnetic field strength is 1~2T, the pulse interval is 3~7s; when the magnetic field strength is >2~5T, the pulse interval is 4~10s (for example, 4~7s).

[0046] Specifically, in step 3, stirring is performed during the leaching process. Considering that the degree of thermal motion of atoms and electrons in various mineral substances is different under different temperature conditions, the leaching activity also has certain differences. Under magnetic field conditions, the temperature and magnetic field have a certain degree of matching to achieve a better enhanced leaching effect; the reaction time is short, the leaching is incomplete, and when a certain reaction time is reached, the reaction is basically complete. Continuing to extend the reaction time cannot significantly increase the leaching rate; stirring mainly provides a certain centrifugal force and shear force, so that the mineral particles and the liquid leaching agent have a good mixing effect, and reduce the surface diffusion layer of the mineral particles. When the stirring speed is too small, it is easy to cause the sedimentation of the mineral particles. When the stirring speed is too large, the mineral particles and the liquid leachate are easy to form a rotation without relative motion, and the mixing effect cannot be achieved; in addition, the pulsed magnetic field also has a certain stirring effect on magnetic minerals. The mechanical stirring effect needs to cooperate with the pulsed magnetic field stirring effect to achieve a better enhanced leaching effect. Comprehensively considered, in the control step 3, the reaction temperature is 120-170°C, the reaction time is 1-3 hours, and the speed provided by the stirring is 500-1500r / min. Exemplarily, the reaction temperature is 130°C, 140°C, 150°C, 160°C, the reaction time is 1.5 hours, 2 hours, 2.5 hours, and the stirring speed is 700 r / min, 1000 r / min, 1200 r / min.

[0047] Specifically, in step 3, the rotation speed is 500-1000 r / min.

[0048] Specifically, in step 3, the stirring is swirl stirring or impeller stirring.

[0049] In the present invention, by accurately controlling the process parameters of each step, the concentration of sulfuric acid used is low, the safety is good, the leaching time is short and the efficiency is high.

[0050] Specifically, the filtration in step 4 is a conventional liquid-solid separation method, including but not limited to filter press.

[0051] like Figure 2 As shown, the present invention also provides a vanadium-titanium magnetite concentrate enhanced leaching device for implementing the above-mentioned enhanced leaching method. The vanadium-titanium magnetite concentrate enhanced leaching device includes a reaction device, a stirring device for stirring the material in the reaction device to provide centrifugal force and shear force, and a magnetic field generating device for providing a magnetic field.

[0052] Specifically, the above-mentioned reaction device includes but is not limited to a reactor, the reactor includes a reactor body 2-1, the reactor body 2-1 is provided with a feed inlet 2-4 and a discharge port 2-5, the reactor body 2-1 is provided with a heating jacket 2-3 outside, and the reactor body 2-1 is provided with a thermocouple 2-2 for measuring the material temperature.

[0053] The stirring device includes a magnetic stirrer 2-6, a stirring paddle 2-7, and a linkage shaft 2-8 connecting the magnetic stirrer 2-6 and the stirring paddle 2-7.

[0054] Specifically, the magnetic field generating device includes a magnetic field coil 1 and a magnetic field controller. The magnetic field coil 1 is arranged outside the heating sleeve 2-3. Considering that the distance between the magnetic field coil 1 and the heating sleeve 2-3 is too large, the inner diameter of the magnetic field coil 1 needs to be increased, and the magnetic field strength will be reduced. Therefore, the distance between the magnetic field coil 1 and the heating sleeve 2-3 is controlled to be 0.7 to 1.5 cm; the magnetic field controller can be used to adjust the magnetic field strength and pulse frequency, and has the function of real-time measurement of the magnetic field strength.

[0055] Specifically, the reaction kettle is made of Hastelloy acid corrosion resistant material or stainless steel with polytetrafluoroethylene lining.

[0056] In the sulfuric acid leaching process of the existing vanadium-titanium magnetite, the leaching effect is poor when the sulfuric acid concentration is low, and concentrated sulfuric acid needs to be used for leaching, which is easy to produce a large amount of high-concentration waste acid. The method of the present invention takes into account that the magnetic field has a certain influence on the thermal motion of atoms and electrons in the material. When the magnetic field is strong enough, it can have a certain influence on the thermodynamics and kinetics of the chemical reaction between the substances. When the magnetic field is weak, the effect is weak and can be ignored. However, for magnetic minerals, there are certain differences in the effects of magnetic elements and non-magnetic elements in the mineral lattice and the magnetic field. The magnetic field can produce vacancy defects in the mineral structure and change the material entropy value from the molecular level by changing the vibration and orientation of magnetic ions in the magnetic mineral. The pulsed magnetic field is an intermittent magnetic field, which has a more significant effect on the disorder of the crystal structure in the magnetic mineral. Therefore, based on the mechanism of the influence of the pulsed magnetic field on the crystal structure of magnetic minerals, it is beneficial to enhance the mineral dissolution activity, and can effectively strengthen the leaching of vanadium-titanium magnetite in a low-concentration sulfuric acid solution to obtain a higher leaching rate.

[0057] The method of the invention utilizes the magnetism of the vanadium-titanium magnetite concentrate itself and adopts a magnetic field to achieve the dissolution of the vanadium-titanium magnetite concentrate under low acid concentration conditions, shorten the reaction time required for acid dissolution, and improve production efficiency.

[0058] Example 1

[0059] like Figure 2 As shown, this embodiment provides a vanadium-titanium magnetite concentrate enhanced leaching device, which includes a reaction device, a stirring device for stirring materials in the reaction device to provide centrifugal force and shear force, and a magnetic field generating device for providing a magnetic field.

[0060] Specifically, the reaction device comprises a reactor, which comprises a reactor body 2-1, on which a feed port 2-4 and a discharge port 2-5 are arranged, a heating jacket 2-3 is arranged outside the reactor body 2-1, and a thermocouple 2-2 for measuring the temperature of the material is arranged inside the reactor body 2-1.

[0061] The stirring device includes a magnetic stirrer 2-6, a stirring paddle 2-7, and a linkage shaft 2-8 connecting the magnetic stirrer 2-6 and the stirring paddle 2-7.

[0062] Specifically, the magnetic field generating device includes a magnetic field coil 1 and a magnetic field controller. The magnetic field coil 1 is arranged outside the heating sleeve 2-3, and the distance between the magnetic field coil 1 and the heating sleeve 2-3 is 0.75 cm.

[0063] Specifically, the reaction kettle is made of stainless steel with a polytetrafluoroethylene lining.

[0064] Example 2

[0065] This embodiment provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, using the device of embodiment 1, comprising the following steps:

[0066] The vanadium-titanium magnetite concentrate was ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate was fully mixed with sulfuric acid solutions of different concentrations according to the ratio of sulfuric acid solution to concentrate of 10mL:1g, and placed in a device with a magnetic field strength of 1T and a pulse interval of 3s, and reacted for 1 hour at 120℃ and a stirring speed of 500r / min; after the leaching reaction was completed, the reaction material was kept at a solution temperature of 100℃ and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron and vanadium. The leaching rates of titanium, iron and vanadium in vanadium-titanium magnetite during the leaching process under different sulfuric acid concentrations are shown in Table 1.

[0067] In this embodiment, under the condition of sulfuric acid concentration of 20% to 30%, the titanium leaching rate reaches more than 82% (for example, 82% to 93%), the iron leaching rate reaches more than 85% (for example, 85% to 96%), and the vanadium leaching rate reaches more than 87% (for example, 87% to 96%), and the leaching effect is good.

[0068] Table 1 Leaching rate of each element in vanadium-titanium magnetite under different sulfuric acid concentration conditions

[0069] Sulfuric acid concentration / % Titanium leaching rate / % Iron leaching rate / % Vanadium leaching rate / % 20 82.41 85.36 87.24 25 86.37 90.48 91.62 30 92.68 94.85 94.31

[0070] Example 3

[0071] This embodiment provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, using the device of embodiment 1, comprising the following steps:

[0072] The vanadium-titanium magnetite concentrate is ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate is mixed with 25% sulfuric acid solution in a ratio of 10mL:1g of sulfuric acid solution to concentrate, and is placed in the device of Example 1. Under different magnetic field strengths and pulse intervals, the reaction is carried out at 150°C and a stirring speed of 1000r / min for 2 hours; after the leaching reaction is completed, the reaction material is kept at a solution temperature of 100°C and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron and vanadium. Under different magnetic field strengths and pulse intervals, the leaching rates of titanium, iron and vanadium in the vanadium-titanium magnetite during the leaching process are shown in Table 2. The leaching effect is not positively correlated with the magnetic field strength, pulse interval, temperature and stirring speed, but requires a certain degree of matching between the magnetic field strength, pulse interval, temperature and stirring speed to significantly improve the leaching effect.

[0073] In this embodiment, the titanium leaching rate reaches more than 58% (e.g., 58% to 93%), the iron leaching rate reaches more than 62% (e.g., 62% to 96%), and the vanadium leaching rate reaches more than 61% (e.g., 61% to 97%), and the leaching effect is good.

[0074] In this embodiment, the preferred scheme is: when the magnetic field strength is 0.1-<1T, the pulse interval is 1-3s, at which time, the titanium leaching rate reaches more than 76% (for example, 76%-79%), the iron leaching rate reaches more than 76% (for example, 76%-80%), and the vanadium leaching rate reaches more than 74% (for example, 74%-80%);

[0075] When the magnetic field strength is 1 to 2 T, the pulse interval is 3 to 7 s, for example, 3 to 6 s, at which time, the titanium leaching rate reaches more than 69% (for example, 69% to 92%), the iron leaching rate reaches more than 71% (for example, 71% to 95%), and the vanadium leaching rate reaches more than 75% (for example, 75% to 97%);

[0076] When the magnetic field strength is >2-5T, the pulse interval is 4-10s. At this time, the titanium leaching rate reaches more than 84% (e.g., 84%-90%), the iron leaching rate reaches more than 87% (e.g., 87%-91%), and the vanadium leaching rate reaches more than 89% (e.g., 89%-92%).

[0077] Table 2 Leaching rate of each element in vanadium-titanium magnetite under different magnetic field strength and pulse interval conditions

[0078]

[0079]

[0080] Example 4

[0081] This embodiment provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, using the device of embodiment 1, comprising the following steps:

[0082] The vanadium-titanium magnetite concentrate is ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate is mixed with 25% sulfuric acid solution in a ratio of 10mL:1g of sulfuric acid solution to concentrate, and placed in the device of Example 1, and reacted for 3 hours under the conditions of magnetic field intensity 2.0T, pulse interval 7s, different reaction temperatures and stirring speeds; after the leaching reaction is completed, the reaction material is kept at a solution temperature of 100°C and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron and vanadium. Under different reaction temperatures and stirring speeds, the leaching rates of titanium, iron and vanadium in the vanadium-titanium magnetite during the leaching process are shown in Table 3. The leaching effect is not positively correlated with the reaction temperature and stirring speed, but requires a certain degree of matching between the reaction temperature and stirring speed to significantly improve the leaching effect.

[0083] In this embodiment, the titanium leaching rate reaches more than 66% (for example, 66% to 90%), the iron leaching rate reaches more than 68% (for example, 68% to 90%), and the vanadium leaching rate reaches more than 71% (for example, 71% to 91%), and the leaching effect is good.

[0084] Compared with Example 3, it can be seen from this embodiment that by prolonging the time, the effect can be optimized under conditions that are not the best magnetic field conditions; the effect can be optimized under conditions of increasing the temperature and reducing the stirring speed; it can be seen that the leaching effect is not positively correlated with the magnetic field strength, pulse interval, temperature and stirring speed, but requires a certain degree of matching among the magnetic field strength, pulse interval, temperature and stirring speed to significantly enhance the leaching effect.

[0085] Table 3 Leaching rate of each element in vanadium-titanium magnetite under different reaction temperatures and stirring speeds

[0086] Reaction temperature / ℃ Stirring speed r / min Titanium leaching rate / % Iron leaching rate / % Vanadium leaching rate / % 120 500 66.45 68.24 71.69 150 500 71.48 73.62 76.14 150 1000 84.37 85.27 87.25 170 500 87.34 89.52 90.18 170 1000 84.38 85.27 86.49 170 1500 83.28 86.89 87.54

[0087] Example 5

[0088] This embodiment provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, using the device of embodiment 1, comprising the following steps:

[0089] The vanadium-titanium magnetite concentrate is ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate is mixed with a 25% sulfuric acid solution at a ratio of 10 mL: 1 g, and placed in the device of Example 1, and reacted for 3 hours under the conditions of a magnetic field intensity of 2.0 T, a pulse interval of 6 s, a reaction temperature of 170 ° C and a stirring speed of 500 r / min; after the leaching reaction is completed, the reaction material is kept at a solution temperature of 100 ° C and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron and vanadium. The leaching rates of titanium, iron and vanadium in the vanadium-titanium magnetite during the leaching process are 91.45%, 95.24% and 96.05%, respectively.

[0090] By changing the conditions such as the magnetic field strength and pulse interval, the leaching effect is improved compared to the best leaching effect in Example 4, indicating that the magnetic field strength, pulse interval, reaction temperature and stirring speed in the leaching process have a certain degree of matching, which can significantly improve the leaching effect.

[0091] Example 6

[0092] This embodiment provides a method for enhanced leaching of vanadium-titanium magnetite concentrate, using the device of embodiment 1, comprising the following steps:

[0093] The vanadium-titanium magnetite concentrate is ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate is fully mixed with a 25% sulfuric acid solution at a ratio of 10 mL: 1 g of sulfuric acid solution to concentrate, and placed in a device with a magnetic field intensity of 2 T and a pulse interval of 5 s, and reacted at 120° C. and a stirring speed of 500 r / min for 1 hour; after the leaching reaction is completed, the reaction material is kept at a solution temperature of 100° C. and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron and vanadium.

[0094] In this embodiment, the titanium leaching rate reaches 93%, the iron leaching rate reaches 95.1%, and the vanadium leaching rate reaches 94.9%, and the leaching effect is good.

[0095] The inventor has conducted a large number of experimental studies during the research process, and now uses some solutions with poor effects as comparative examples.

[0096] Comparative Example 1

[0097] This comparative example provides a method for leaching vanadium-titanium magnetite concentrate, comprising the following steps:

[0098] The vanadium-titanium magnetite concentrate was ground and sieved to obtain a vanadium-titanium magnetite concentrate with a 200-mesh sieve accounting for more than 95%; the vanadium-titanium magnetite concentrate was mixed with a 25% sulfuric acid solution at a ratio of 10 mL: 1 g, and placed in a reaction device without a magnetic field device, and reacted for 3 hours under different reaction temperatures and stirring speeds; after the leaching reaction was completed, the reaction material was kept at a solution temperature of 100 ° C and filtered through a filter press to obtain a leachate and leaching residue containing titanium, iron, and vanadium. The leaching rates of titanium, iron, and vanadium in the vanadium-titanium magnetite during the leaching process under different reaction temperatures and stirring speeds are shown in Table 4.

[0099] Table 4 Leaching rate of each element in vanadium-titanium magnetite

[0100] Reaction temperature / ℃ Stirring speed r / min Titanium leaching rate / % Iron leaching rate / % Vanadium leaching rate / % 120 500 36.81 42.37 45.69 150 500 56.78 78.36 79.67 150 1000 67.52 81.68 85.34 170 1000 68.57 82.34 84.38 170 1500 56.89 76.37 75.42

[0101] By comparing Example 3 and Comparative Example 1, it can be seen that under the action of the pulsed magnetic field, the leaching effect of the vanadium-titanium magnetite concentrate is significantly enhanced; under the action of the magnetic field, the effects of the reaction temperature and the stirring speed on the leaching effect are not positively correlated, but have a certain matching system; under the condition of no magnetic field, the higher the reaction temperature, the better the leaching effect, and the stirring speed has a certain optimal range. If the stirring speed is too high, the solid particles and the liquid will rotate at the same speed, but will not have a stirring effect.

[0102] Comparative Example 2

[0103] This comparative example provides a method for leaching vanadium-titanium magnetite concentrate, which is basically the same as the steps in Example 3, except that the magnetic field intensity is 5T and the pulse interval is 30s.

[0104] In this comparative example, the titanium leaching rate is 15.42%, the iron leaching rate is 60.87%, and the vanadium leaching rate is 65.54%. Under this condition, due to the long pulse interval and the large magnetic field strength, there is a certain effect on the leaching of magnetite minerals in the vanadium iron magnetite concentrate, which is reflected in the iron and vanadium leaching rates can reach more than 60%, but the leaching effect on the ilmenite minerals is poor. In addition, the large magnetic field intensity and pulse interval will also cause the hydrolysis of the titanium component after dissolution, thus reflecting the effect of low titanium leaching rate. Under this condition, it is impossible to achieve the simultaneous and efficient leaching of the three valuable metals of titanium, vanadium and iron in the vanadium iron magnetite.

[0105] Comparative Example 3

[0106] This comparative example provides a method for leaching vanadium-titanium magnetite concentrate, which is the same as Example 5, except that a sulfuric acid solution with a higher sulfuric acid concentration is used. The leaching results are shown in Table 5 below. It can be seen that under the process conditions of the present invention, there is no need to use high-concentration sulfuric acid, and the use of high-concentration sulfuric acid has no obvious gain effect on the leaching effect. The process conditions of the present invention have stimulated the mineral dissolution activity to the extreme.

[0107] Table 5 Leaching rate results

[0108] Sulfuric acid concentration / % Titanium leaching rate / % Iron leaching rate / % Vanadium leaching rate / % 40 91.75 95.67 96.12 50 91.51 95.54 96.04 60 91.85 95.99 96.74

[0109] Comparative Example 4

[0110] This comparative example provides a method for leaching vanadium-titanium magnetite concentrate. Compared with Example 5, the leaching temperature, time, stirring speed, liquid-solid ratio and other conditions are the same, except that: this comparative example uses high-concentration sulfuric acid for leaching under the condition of no magnetic field, the sulfuric acid concentration is 80%, and the leaching rates of titanium, vanadium and iron are 85.71%, 89.67% and 90.73% respectively. By comparison, it is found that under the condition of magnetic field, the leaching effect of low-concentration sulfuric acid is slightly better than that of high-concentration sulfuric acid under the condition of no magnetic field.

[0111] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for enhanced leaching of vanadium-titanium magnetite concentrate, characterized in that: The method comprises the following steps: Step 1: Grind and screen the vanadium-titanium magnetite concentrate; Step 2: Mix the vanadium-titanium magnetite concentrate with the sulfuric acid solution, and stir evenly to obtain a mixed slurry; Step 3: placing the mixed slurry into a device with a magnetic field to perform a leaching reaction; Step 4: After the leaching reaction is completed, the reaction material is filtered to obtain a leaching solution containing titanium, vanadium and iron.

2. The method for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step 3, the magnetic field adopts a pulsed magnetic field.

3. The method for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step 3, the magnetic field strength of the pulsed magnetic field is 0.1 to 5 T, and the pulse interval is 1 to 10 s.

4. The method for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In step 2, the concentration of the sulfuric acid solution is 20% to 30%.

5. The method for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In the step 2, the ratio of the sulfuric acid solution to the concentrate is 5 mL: 1 g to 15 mL: 1 g.

6. The method for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 1, characterized in that: In the step 3, the reaction temperature is 120-170°C.

7. A vanadium-titanium magnetite concentrate enhanced leaching device, characterized in that: The vanadium-titanium magnetite concentrate enhanced leaching device is used to implement the method for enhanced leaching of vanadium-titanium magnetite concentrate according to any one of claims 1 to 6, and the vanadium-titanium magnetite concentrate enhanced leaching device includes a reaction device, a stirring device for stirring the material in the reaction device to provide centrifugal force and shear force, and a magnetic field generating device for providing a magnetic field.

8. The device for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 7, characterized in that: The reaction device comprises a reaction kettle, which comprises a reaction kettle body (2-1), the reaction kettle body (2-1) is provided with a feed inlet (2-4) and a discharge outlet (2-5), a heating jacket (2-3) is provided outside the reaction kettle body (2-1), and a thermocouple (2-2) for measuring the temperature of the material is provided inside the reaction kettle body (2-1).

9. The device for enhanced leaching of vanadium-titanium magnetite concentrate according to claim 7, characterized in that: The stirring device comprises a magnetic stirrer (2-6), a stirring paddle (2-7), and a linkage shaft (2-8) connecting the magnetic stirrer (2-6) and the stirring paddle (2-7).

10. The device for enhanced leaching of vanadium-titanium magnetite concentrate according to any one of claims 7 to 9, characterized in that: The magnetic field generating device comprises a magnetic field coil (1) and a magnetic field controller, and the magnetic field coil (1) is arranged outside the heating sleeve (2-3).

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