Fine-grained vanadium-titanium iron concentrate filtering pretreatment method

Abstract

The application discloses a kind of fine-grained vanadium-titanium iron concentrate filtration pretreatment methods, comprising the following steps: fine-grained vanadium-titanium iron concentrate and water are mixed and the mass fraction of the fine-grained vanadium-titanium iron concentrate in the obtained suspension is adjusted to predetermined concentration, obtain first slurry;First slurry is passed through demagnetizer, and demagnetization is carried out, and second slurry is obtained;Second slurry is treated with ultrasonic wave, and third slurry is obtained;Third slurry is mixed with a predetermined amount of flocculating agent and then sent into a magnetic separation column after stirring, the operating parameters of the magnetic separation column are adjusted, the height difference between the mixed slurry in the magnetic separation column cylinder and the overflow surface is controlled, and the mass fraction of fine-grained vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separation column is controlled to be a predetermined concentration, and the flocculating agent is prepared from corn starch;Vacuum filtration is carried out on the fourth slurry.It is beneficial to increase the agglomeration diameter of fine-grained vanadium-titanium iron concentrate particles before filtration, reduce the moisture content of the product obtained after filtration of fine-grained vanadium-titanium iron concentrate, and improve the filtration efficiency.

Description

Technical Field

[0001] This invention relates to the field of vanadium-titanium magnetite mining and beneficiation technology, and in particular to a method for filtering and pretreatment of fine-grained vanadium-titanium iron concentrate. Background Technology

[0002] The main process for pig iron production in my country's steel industry is mining-benefiting-sintering (pelletizing)-blast furnace, which is also the main route for the comprehensive utilization of vanadium-titanium magnetite. The main iron-bearing mineral in vanadium-titanium magnetite—titanium magnetite—is a complex mineral formed from magnetite, titanium-bearing magnetite, ilmenite, magnesium aluminum spinel, chromite spinel, and ilmenite. Iron concentrate produced using vanadium-titanium magnetite is rich in TiO2 and V2O5, CaO, MgO, Al2O3, and SiO2, generally higher than that of ordinary iron ore. Due to the high TiO2 content in vanadium-titanium iron concentrate, the requirements for SiO2 and CaO during sintering, and the TiO2 content in blast furnace slag, the TFe grade in blast furnace feed for ironmaking using vanadium-titanium iron concentrate has long been stable at 50.5%–51.5%, and the fuel ratio in the ironmaking process is as high as 540–570 kg / t pig iron, far exceeding the level of ironmaking using ordinary iron ore.

[0003] In recent years, high prices for coal, coke, and imported iron ore, coupled with a sharp decline in global steel prices, have forced steel companies to reduce pig iron costs. Experience in blast furnace ironmaking shows that a 1% increase in the TFe grade of blast furnace feed can reduce the fuel ratio by 2% and increase the blast furnace utilization coefficient by 3%. Conversely, a 1% increase in the TFe grade of vanadium-titanium iron concentrate can increase the TFe grade of blast furnace feed by 0.4–0.6 percentage points. Therefore, increasing the TFe grade of vanadium-titanium iron concentrate is beneficial for reducing the fuel ratio in blast furnace ironmaking, lowering pig iron costs, and reducing carbon emissions. Currently, due to the urgent need for low-carbon manufacturing, the steel industry's demand for high-quality iron concentrate is becoming increasingly pressing. Iron concentrate quality is trending towards higher TFe grades and finer particle sizes, making efficient dehydration and filtration of fine-grained iron concentrate even more crucial.

[0004] Currently, the dewatering and filtration method for fine-grained vanadium-titanium iron concentrate in the Panzhihua-Xichang region is magnetic separation concentrate-concentration-filtration. In this method, the mass fraction of fine-grained vanadium-titanium iron concentrate in the suspension obtained after mixing fine-grained vanadium-titanium iron concentrate and water is 40% to 60%. The filtration equipment for this method is mainly various types of disc vacuum filters, or filter presses or ceramic filters. The moisture content in the filter cake of fine iron concentrate after filtration using the above method is 12%–14%, indicating a high water content in the product. The mass fraction of fine iron concentrate in the overflow of the above filtration method is >10%, indicating that the limited capacity of the filtration equipment leads to the loss of fine particles in the fine vanadium-titanium iron concentrate through overflow circulation. The mass fraction of fine iron concentrate in the filtrate of the above filtration method is >2%, indicating that fine particles in the fine vanadium-titanium iron concentrate are lost by entering the filtrate through the filter cloth. Furthermore, the above filtration method suffers from the problem of fine particles in the fine vanadium-titanium iron concentrate clogging the filter cloth pores, leading to a high frequency of filter cloth or filtration equipment replacement. These factors affect the quality of the product after filtration of fine vanadium-titanium iron concentrate and hinder efficient filtration of the fine vanadium-titanium iron concentrate. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a pretreatment method for filtering fine-grained vanadium-titanium iron concentrate, which solves the technical problems of high moisture content and low filtration efficiency in existing dewatering and filtering methods for fine-grained vanadium-titanium iron concentrate.

[0006] On one hand, embodiments of the present invention disclose a method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration, comprising the following steps:

[0007] Fine-grained vanadium-titanium iron concentrate is mixed with water and the mass fraction of the fine-grained vanadium-titanium iron concentrate in the resulting suspension is adjusted to a predetermined concentration to obtain a first slurry.

[0008] The first slurry is demagnetized by a demagnetizer to obtain the second slurry;

[0009] The second slurry is subjected to ultrasonic treatment to obtain the third slurry;

[0010] The third slurry is mixed with a predetermined amount of flocculant and then fed into a magnetic separation column. The operating parameters of the magnetic separation column are adjusted to control the height difference between the mixed slurry inside the magnetic separation column cylinder and the overflow surface. The mass fraction of fine vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separation column is controlled to a predetermined concentration. The flocculant is prepared from corn starch.

[0011] The fourth slurry was vacuum filtered.

[0012] According to one embodiment of the present invention, the fine-grained vanadium-titanium iron concentrate is obtained from vanadium-titanium magnetite ore through a three-stage closed-circuit crushing, a three-stage grinding, and a five-stage weak magnetic separation. The mass percentage of particles with a size less than 0.043 mm in the fine-grained vanadium-titanium iron concentrate is greater than 85%, and the mass percentage of particles with a size less than 0.074 mm in the fine-grained vanadium-titanium iron concentrate is greater than 98%.

[0013] According to one embodiment of the present invention, the mass percentages of each component in the fine-grained vanadium-titanium iron concentrate are as follows: TFe 50-60%, TiO2 10-20%, V2O5 <1%, FeO 30-40%, SiO2 <3%, CaO <1%, MgO <3%, Al2O3 <4%, MnO <1%, Cr <0.1%, Na2O <0.1%, and K2O <0.01%.

[0014] According to one embodiment of the present invention, the predetermined concentration is 40% to 60%.

[0015] According to one embodiment of the present invention, the frequency of the ultrasonic waves during the ultrasonic treatment of the second slurry is 20 to 38 kHz.

[0016] According to one embodiment of the present invention, the predetermined amount of flocculant is a ratio of the volume of the flocculant to the mass of the fine-grained vanadium-titanium iron concentrate dry ore of 800-1200 mL / t.

[0017] According to one embodiment of the present invention, the flocculant is prepared as follows: corn starch is added to 400 mL of a 0.5% NaOH solution, stirred evenly, and then stirred and evaporated at 150°C at a predetermined stirring speed to obtain a first evaporated substance; the first evaporated substance is added to 200 mL of a 1% hydrochloric acid solution, stirred evenly, and then stirred and evaporated at 150°C at a predetermined stirring speed to obtain a second evaporated substance; the second evaporated substance is dissolved in water to prepare the flocculant with a 1% mass fraction.

[0018] According to one embodiment of the present invention, the predetermined stirring speed is 900 to 1100 rad / min.

[0019] According to one embodiment of the present invention, adjusting the operating parameters of the magnetic separator column includes adjusting the fixed magnetic field strength of the magnetic separator column to 30-50 Oe, adjusting the circulating magnetic field strength of the magnetic separator column to 150-200 Oe, and adjusting the magnetic field switching cycle of the magnetic separator column to 3-5 s.

[0020] According to one embodiment of the present invention, the method further includes adjusting the slurry flow valve, the bottom water supply valve, and the discharge valve of the magnetic separator to control the height difference between the mixed slurry inside the magnetic separator cylinder and the overflow surface to be 1 to 3 cm.

[0021] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0022] The pretreatment method for filtering fine-grained vanadium-titanium iron concentrate provided by this invention involves demagnetizing and ultrasonically treating the fine-grained vanadium-titanium iron concentrate to break down coarse particles into fine particles and disperse coarse agglomerate nuclei. The resulting third slurry is then mixed with a flocculant and fed into a magnetic separation column for magnetization. This process allows the original fine particles and the dispersed fine particles in the fine-grained vanadium-titanium iron concentrate to agglomerate again, thereby increasing the agglomeration diameter of the fine-grained vanadium-titanium iron concentrate particles before filtration, reducing the surface energy of the particles, and consequently reducing the moisture content of the product obtained after filtration. This improves the quality of the product and significantly promotes efficient filtration of fine-grained vanadium-titanium iron concentrate. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a filtration pretreatment method for fine-grained vanadium-titanium iron concentrate disclosed in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0026] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0027] As shown in Figure 1, an embodiment of the present invention discloses a method for pre-filtration of fine-grained vanadium-titanium iron concentrate, comprising the following steps:

[0028] S10. Mix fine-grained vanadium-titanium iron concentrate with water and adjust the mass fraction of the fine-grained vanadium-titanium iron concentrate in the resulting suspension to a predetermined concentration to obtain the first slurry.

[0029] S20. The first slurry is demagnetized by a demagnetizer to obtain the second slurry;

[0030] S30. The second slurry is subjected to ultrasonic treatment to obtain the third slurry;

[0031] S40. After mixing and stirring the third slurry with a predetermined amount of flocculant, feed it into the magnetic separation column. Adjust the operating parameters of the magnetic separation column, control the height difference between the mixed slurry inside the magnetic separation column cylinder and the overflow surface, and control the mass fraction of fine vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separation column to a predetermined concentration. The flocculant is prepared with corn starch.

[0032] S50. Vacuum filter the fourth slurry.

[0033] In the above embodiments, demagnetizing the first slurry can break down the coarse particles in the fine vanadium-titanium iron concentrate that are agglomerated due to magnetic properties into fine particles, and disperse the agglomerated crystal nuclei within the coarse particles. Then, the demagnetized second slurry is subjected to ultrasonic treatment, which further breaks down more agglomerated coarse particles into fine particles and disperses more agglomerated crystal nuclei. Finally, the resulting third slurry is mixed with a flocculant and fed into a magnetic separation column for magnetization. This allows the original fine particles and the dispersed fine particles in the fine vanadium-titanium iron concentrate to agglomerate again, thereby increasing the agglomeration diameter of the fine vanadium-titanium iron concentrate particles before filtration, significantly reducing the surface energy of the fine vanadium-titanium iron concentrate particles, and consequently, significantly reducing the water content of the product obtained after filtration, greatly improving the quality of the product, and greatly promoting the efficient filtration of fine vanadium-titanium iron concentrate.

[0034] In some embodiments, fine-grained vanadium-titanium iron concentrate is obtained from vanadium-titanium magnetite ore through a three-stage closed-circuit crushing, three-stage grinding, and five-stage weak magnetic separation. The mass percentage of particles smaller than 0.043 mm (-325 mesh) in the fine-grained vanadium-titanium iron concentrate is >85%, and the mass percentage of particles smaller than 0.074 mm is >98%. This process helps improve the quality of the fine-grained vanadium-titanium iron concentrate. The particles in this fine-grained vanadium-titanium iron concentrate are relatively fine, with an average particle size <0.025 mm. Most of the fine-grained iron concentrate forms magnetic agglomerates with relatively coarse particles, while some micro-fine particles are dispersed due to the lack of agglomeration nuclei.

[0035] In some embodiments, the mass percentages of each component in the fine-grained vanadium-titanium iron concentrate are as follows: TFe 50-60%, TiO2 10-20%, V2O5 <1%, FeO 30-40%, SiO2 <3%, CaO <1%, MgO <3%, Al2O3 <4%, MnO <1%, Cr <0.1%, Na2O <0.1%, and K2O <0.01%.

[0036] In other embodiments, the mass percentages of each component in the fine-grained vanadium-titanium iron concentrate are as follows: TFe 55.93%, TiO2 12.55%, V2O5 0.60%, FeO 33.77%, SiO2 2.36%, CaO 0.673%, MgO 2.44%, Al2O3 3.56%, MnO 0.334%, Cr 0.018%, Na2O 0.035%, and K2O <0.01%.

[0037] In some embodiments, the mass fraction of the fine-grained vanadium-titanium iron concentrate in the resulting suspension is adjusted to a predetermined concentration of 40% to 60%.

[0038] In some embodiments, the main mineral in the fine-grained vanadium-titanium iron concentrate is titanomagnetite, which accounts for more than 93% of the total mass. The fine-grained vanadium-titanium iron concentrate also includes a small amount of pyroxene, feldspar, amphibole and olivine. The gangue minerals are adhered to or rendered by titanomagnetite on their surfaces. Most of the ilmenite and MgA spinel are interspersed in the titanomagnetite matrix in fine bands and networks, forming guest crystal minerals.

[0039] In some embodiments, the ultrasonic frequency during the ultrasonic treatment of the second slurry is 20–38 kHz. This is beneficial for breaking down more coarse agglomerates into fine particles and dispersing more agglomerate nuclei.

[0040] In some embodiments, the predetermined amount of flocculant is a ratio of flocculant volume to the mass of dry fine vanadium-titanium iron concentrate of 800–1200 mL / t. The added flocculant, through surface electrostatic interaction and chemical reaction with the fine vanadium-titanium iron concentrate, facilitates the agglomeration of both existing and dispersed fine particles in the concentrate. This increases the agglomeration diameter of the fine vanadium-titanium iron concentrate particles before filtration, reduces their surface energy, and consequently reduces the moisture content of the product obtained after filtration.

[0041] In some embodiments, the flocculant is prepared as follows: corn starch is added to 400 mL of a 0.5% (w / w) NaOH solution, stirred evenly, and then evaporated to dryness at 150°C with a predetermined stirring speed to obtain a first evaporated substance; the first evaporated substance is added to 200 mL of a 1% (w / w) hydrochloric acid solution, stirred evenly, and then evaporated to dryness at 150°C with a predetermined stirring speed to obtain a second evaporated substance; the second evaporated substance is dissolved in water to prepare a 1% (w / w) flocculant. In this embodiment, the corn starch molecular structure is changed by subjecting it to causticization and chlorination reactions, which facilitates the full agglomeration of the original fine particles and the dispersed fine particles in the fine vanadium-titanium iron concentrate.

[0042] In some embodiments, the predetermined stirring speed is 900–1100 rad / min. This facilitates the causticization and chlorination reactions of corn starch, thereby promoting changes in the molecular structure of the corn starch.

[0043] In some embodiments, adjusting the operating parameters of the magnetic separator includes adjusting the fixed magnetic field strength of the magnetic separator to 30–50 Oe, adjusting the circulating magnetic field strength of the magnetic separator to 150–200 Oe, and adjusting the magnetic field switching cycle of the magnetic separator to 3–5 s. This allows the original fine particles and the dispersed fine particles in the fine-grained vanadium-titanium iron concentrate to fully agglomerate, thereby increasing the agglomeration diameter of the fine-grained vanadium-titanium iron concentrate particles before filtration, significantly reducing the surface energy of the fine-grained vanadium-titanium iron concentrate particles, and thus significantly reducing the moisture content of the product obtained after filtration, greatly promoting the efficient filtration of the fine-grained vanadium-titanium iron concentrate.

[0044] In some embodiments, the method further includes adjusting the slurry flow valve, bottom water supply valve, and discharge valve of the magnetic separation column to control the height difference between the mixed slurry and the overflow surface inside the magnetic separation column to be 1-3 cm. In this embodiment, by controlling the height difference between the mixed slurry and the overflow surface inside the magnetic separation column to be 1-3 cm, the mixed slurry can be prevented from overflowing while keeping the entire mixed slurry within the magnetic field range. This facilitates the agglomeration of fine particles in the mixed slurry and the dispersed fine particles, thereby increasing the agglomeration diameter of the fine vanadium-titanium iron concentrate particles before filtration. This significantly reduces the surface energy of the fine vanadium-titanium iron concentrate particles, which in turn significantly reduces the water content of the product obtained after filtration, greatly promoting the efficient filtration of the fine vanadium-titanium iron concentrate.

[0045] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0046] Example

[0047] The main physicochemical properties of the fine-grained vanadium-titanium iron concentrate sample used in this example are as follows:

[0048] The fine-grained vanadium-titanium iron concentrate sample contained 55.93% TFe, 12.55% TiO2, 0.60% V2O5, 3.77% FeO, 2.36% SiO2, 0.673% CaO, 2.44% MgO, 3.56% Al2O3, 0.334% MnO, and Cr. The sample contains 0.018% Na₂O, 0.035% Na₂O, and <0.01% K₂O. The mass percentage of particles smaller than 0.074 mm is 98.09%, and particles smaller than 0.043 mm are 91.62%. This sample is a vanadium-titanium magnetite concentrate obtained from raw vanadium-titanium magnetite ore through a three-stage closed-circuit crushing, three-stage grinding, and five-stage weak magnetic separation. The mineral particles in this sample are relatively fine, with an average particle size <0.025 mm. Most of the fine-grained iron concentrate forms magnetic agglomerates with relatively coarser particles, while some micro-fine particles are dispersed due to the lack of agglomeration nuclei. The main mineral in the sample is titanomagnetite, accounting for >93%, with minor amounts of pyroxene, feldspar, amphibole, and olivine. Gangue minerals are adhered to or stained by titanomagnetite on their surfaces. Most ilmenite and MgA spinel are interspersed in fine bands and networks within the titanomagnetite matrix, forming guest crystals.

[0049] The steps for pre-filtration of the above-mentioned fine-grained vanadium-titanium iron concentrate sample in this embodiment are as follows:

[0050] (1) Fine vanadium-titanium iron concentrate (with a particle size of less than 0.043 mm accounting for 91.62% by mass) obtained by three-stage grinding and five-stage magnetic separation is mixed with water and the mass fraction of fine vanadium-titanium iron concentrate in the resulting suspension is adjusted to 55%. In this step, an XTD-15L mixing tank is used to stir evenly to obtain the first slurry.

[0051] (2) The first slurry, which is stirred evenly, is passed by gravity through a GMT-6 high-frequency pulse demagnetizer to demagnetize it and obtain the second slurry;

[0052] (3) The prepared flocculant is added dropwise to the XBSL1 / 4 vertical sand pump 1. The amount of flocculant used is the ratio of the volume of flocculant to the mass of fine vanadium-titanium iron concentrate dry ore of 1000 mL / t. The preparation method of the flocculant is as follows: corn starch is added to 400 mL of NaOH solution with a mass fraction of 0.5%, stirred evenly, and then stirred and evaporated at 150℃ with a stirring speed of 900-1100 rad / min to obtain the first evaporated material; the first evaporated material is added to 200 mL of hydrochloric acid solution with a mass fraction of 1%, stirred evenly, and then stirred and evaporated at 150℃ with a stirring speed of 900-1100 rad / min to obtain the second evaporated material; the second evaporated material is dissolved in water to prepare a flocculant with a mass fraction of 1%.

[0053] (4) The second slurry after demagnetization is fed into the XBSL1 / 4 vertical sand pump and mixed with flocculant before being pumped to the JYF-CXZ10 magnetic separation column. The fixed magnetic field strength is adjusted to 40Oe, the circulating magnetic field strength is 180Oe, and the magnetic field transformation cycle is 4s.

[0054] (5) Adjust the feed slurry flow valve, bottom water replenishment valve and discharge valve of the JYF-CXZ10 magnetic separator column to stabilize the height difference between the slurry in the cylinder and the overflow surface at 2cm, and control the mass fraction of fine vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separator column to be 50%.

[0055] (6) Take the slurry from the JYF-CXZ10 magnetic separation column unloading valve and filter it using the XTLZ-ф260-200 multi-purpose disc vacuum filter. After filtration, weigh the filter cake, weigh the dry ore after drying, record the thickness of the filter cake and calculate the moisture content of the filter cake. Record the results in Table 1 below.

[0056] The fine-grained vanadium-titanium iron concentrate sample was subjected to two more pretreatment processes according to the above embodiments. After filtration, the weight of the filter cake, the weight of the dried ore, the thickness of the filter cake, and the moisture content of the filter cake were recorded and entered into Table 1 below. Under the same conditions, the untreated fine-grained vanadium-titanium iron concentrate was filtered three times. The weight of the filter cake obtained after filtration, the weight of the dried ore, the thickness of the filter cake, and the moisture content of the filter cake were recorded and entered into Table 1 below.

[0057] Table 1 Comparative test results of filtration pretreatment of fine-grained vanadium-titanium iron concentrate

[0058]

[0059] The above experimental results and the data in Table 1 show that, using the above pretreatment method, the moisture content of the filter cake obtained after filtration of the fine-grained vanadium-titanium iron concentrate can be reduced to <11%. Under the same conditions, the moisture content of the filter cake obtained after filtration of the untreated fine-grained vanadium-titanium iron concentrate is reduced by 4.13 percentage points. Moreover, the moisture content of the filter cake of the pretreated fine-grained vanadium-titanium iron concentrate does not change significantly with the increase of the filter cake thickness.

[0060] In summary, the fine-grained vanadium-titanium iron concentrate filtration pretreatment method disclosed in this invention involves demagnetizing and ultrasonically treating the fine-grained vanadium-titanium iron concentrate to break down coarse particles into fine particles and disperse coarse agglomerate nuclei. The resulting third slurry is then mixed with a flocculant and fed into a magnetic separation column for magnetization. This process allows the original fine particles and the dispersed fine particles in the fine-grained vanadium-titanium iron concentrate to agglomerate again, thereby increasing the agglomeration diameter of the fine-grained vanadium-titanium iron concentrate particles before filtration, reducing the surface energy of the particles, and consequently reducing the moisture content of the product obtained after filtration. This improves the quality of the product and significantly promotes efficient filtration of the fine-grained vanadium-titanium iron concentrate.

[0061] It should be noted that the components or steps in the above embodiments can be interchanged, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of this invention, and the protection scope of this invention should not be limited to the above embodiments.

[0062] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order (depending on whether deletion is necessary). Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0063] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration, characterized in that, Includes the following steps: Fine-grained vanadium-titanium iron concentrate is mixed with water and the mass fraction of the fine-grained vanadium-titanium iron concentrate in the resulting suspension is adjusted to a predetermined concentration to obtain a first slurry. The first slurry is demagnetized by a demagnetizer to obtain the second slurry; The second slurry is subjected to ultrasonic treatment to obtain the third slurry; The third slurry is mixed with a predetermined amount of flocculant and then fed into a magnetic separation column. The operating parameters of the magnetic separation column are adjusted to control the height difference between the mixed slurry inside the magnetic separation column cylinder and the overflow surface to be 1-3 cm. The mass fraction of fine vanadium-titanium iron concentrate in the fourth slurry flowing out of the magnetic separation column is controlled to be the predetermined concentration. The flocculant is prepared from corn starch. The fourth slurry was vacuum filtered.

2. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The fine-grained vanadium-titanium iron concentrate is obtained from vanadium-titanium magnetite ore through a three-stage closed-circuit crushing, a three-stage grinding, and a five-stage weak magnetic separation. The mass percentage of particles smaller than 0.043 mm in the fine-grained vanadium-titanium iron concentrate is greater than 85%, and the mass percentage of particles smaller than 0.074 mm in the fine-grained vanadium-titanium iron concentrate is greater than 98%.

3. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The mass percentages of each component in the fine-grained vanadium-titanium iron concentrate are as follows: TFe 50-60%, TiO2 10-20%, V2O5 <1%, FeO 30-40%, SiO2 <3%, CaO <1%, MgO <3%, Al2O3 <4%, MnO <1%, Cr <0.1%, Na2O <0.1%, K2O <0.01%.

4. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The predetermined concentration is 40% to 60%.

5. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The ultrasonic frequency during the ultrasonic treatment of the second slurry is 20–38 kHz.

6. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The predetermined amount of flocculant is defined as the ratio of the volume of the flocculant to the mass of the fine-grained vanadium-titanium iron concentrate dry ore, which is 800–1200 mL / t.

7. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, The flocculant is prepared as follows: corn starch is added to 400 mL of 0.5% NaOH solution, stirred evenly, and then evaporated at 150°C with a predetermined stirring speed to obtain a first evaporated substance; the first evaporated substance is added to 200 mL of 1% hydrochloric acid solution, stirred evenly, and then evaporated at 150°C with a predetermined stirring speed to obtain a second evaporated substance; the second evaporated substance is dissolved in water to prepare the flocculant with a mass fraction of 1%.

8. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 7, characterized in that, The predetermined stirring speed is 900–1100 rad / min.

9. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, Adjusting the operating parameters of the magnetic separator includes adjusting the fixed magnetic field strength of the magnetic separator to 30-50 Oe, adjusting the circulating magnetic field strength of the magnetic separator to 150-200 Oe, and adjusting the magnetic field switching cycle of the magnetic separator to 3-5 s.

10. The method for pre-treatment of fine-grained vanadium-titanium iron concentrate by filtration according to claim 1, characterized in that, It also includes adjusting the slurry flow valve, bottom water supply valve, and discharge valve of the magnetic separator to control the height difference between the mixed slurry and the overflow surface inside the magnetic separator cylinder.

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