Method for extracting iron and reducing titanium from vanadium-titanium-iron concentrate

Abstract

The invention discloses a method for extracting iron and reducing titanium from vanadium-titanium-iron concentrate, and belongs to the technical field of mineral separation. The invention provides a method for extracting iron and reducing titanium from vanadium-titanium-iron ore concentrate in order to realize the removal of Ti in titanomagnetite with the same internal mass appearance, which comprises the following steps: grinding, filtering, drying and scattering the vanadium-titanium-iron ore concentrate, uniformly mixing with a calcium source, roasting, grinding the roasted material, and carrying out low-intensity magnetic separation and reverse flotation to obtain the iron ore concentrate. According to the method, the vanadium-titanium-iron concentrate and CaCO3 or CaO are roasted, Ti in titanomagnetite is transferred into perovskite or iron titanate and the like from the titanomagnetite, then through ore grinding and low-intensity magnetic separation, all components in roasted materials are fully dissociated, the reverse flotation process is optimized, the grade of TFe in the iron concentrate is improved, and the grade of TiO2 in the iron concentrate is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to a method for increasing iron and reducing titanium in vanadium-titanium iron concentrate. Background Art

[0002] Vanadium-titanium magnetite is a composite mineral resource with multiple valuable components such as iron, vanadium, and titanium. It contains valuable components such as iron, titanium, sulfur, and cobalt. It is an important strategic resource recognized by countries around the world and has extremely high comprehensive utilization value. The main iron mineral in vanadium-titanium magnetite is titanomagnetite, which is the main target mineral for iron recovery in mineral processing. Because titanomagnetite is a magnetite in which Fe is replaced by Ti in the crystal lattice and contains spinel, ilmenite spar, and ilmenite dissolution, the vanadium-titanium iron concentrate produced by mineral processing has a low TFe grade and a high TiO2 grade.

[0003] Since vanadium-titanium iron concentrate has the characteristics of low TFe grade and high TiO2 grade, it leads to high energy consumption, low blast furnace utilization coefficient and high smelting production cost in the subsequent blast furnace smelting process, which greatly limits the utilization value of vanadium-titanium iron concentrate.

[0004] CN109174441A discloses a beneficiation method for vanadium-titanium iron concentrate for iron extraction, titanium reduction and sulfur reduction, and the steps are as follows: A. adding water to the vanadium-titanium iron concentrate raw material to prepare a slurry with a solid content of 35% to 45%, and conveying it to a classification system; B. passing qualified particles with a particle size less than a set value a directly into the separation system through the classification system, and the remaining coarse particles into the grinding system; the solid content of the coarse particles is controlled to be 65% to 75% before entering the grinding system, and the qualified particles with a particle size less than a set value a are obtained and enter the separation system; the value of a is 180 mesh to 200 mesh; C. in the separation system, firstly performing multi-stage separation by a magnetic separator to obtain a semi-finished iron concentrate; D. adding the semi-finished iron concentrate to the separation system; water to form a slurry with a solid content of 30% to 50%; E, adding sulfuric acid with a concentration of 20% to 25% to the slurry of the semi-finished iron ore concentrate, and controlling the pH value to 3.5 to 4.5; and adding butyl ammonium xanthate, butyl ammonium black medicine, and 2# oil, and mixing evenly to obtain a flotation slurry; wherein the addition ratio is 400g to 600g of sulfuric acid, 280g to 320g of butyl ammonium black medicine, 280g to 320g of butyl ammonium xanthate, and 15g to 25g of 2# oil per ton of solid content of the semi-finished iron ore concentrate; F, the flotation slurry is subjected to flotation roughing and flotation scavenging in sequence to obtain a flotation concentrate and a flotation tailing, wherein the flotation concentrate is a sulfide-cobalt ore, and the flotation tailing is a finished iron ore concentrate.

[0005] CN117065917A discloses a new process for improving the quality of fine iron concentrate and reducing the titanium content, comprising the following steps: step (1), ultrafine grinding: ultrafine grinding the fine iron concentrate, controlling the fineness of the grinding product to -20 μm with an occupancy rate of more than 95%; step (2), full open circuit short process reverse flotation after weak magnetic separation: conventional weak magnetic separation is performed on the slurry after ultrafine grinding, and then full open circuit short process reverse flotation is performed on the weak magnetic concentrate to obtain the final iron concentrate; the collector used in the reverse flotation is a new combined collector NaOL-OHA, and the mass composition ratio of the new combined collector NaOL-OHA is: 70-90% sodium oleate (NaOL) and 10-30% octylhydroxamic acid (OHA).

[0006] However, the above two methods can only remove TiO2 from ferro-titanium ore in the form of coarse guest crystal minerals in titano-magnetite, thereby achieving the purpose of reducing the grade of TiO2 in iron concentrate, but cannot remove Ti in the form of endoisomorphic Ti in titano-magnetite, and the effect of removing Ti in the form of endoisomorphic Ti in titano-magnetite is very limited. Therefore, it is urgent to develop a method that can improve the grade of TFe in vanadium-titanium iron concentrate and reduce the grade of TiO2, so as to improve the utilization value of vanadium-titanium magnetite. Summary of the invention

[0007] The object of the present invention is to provide a method for removing Ti isomorphously present in titanomagnetite to improve the TFe grade of vanadium-titanium iron concentrate and reduce the TiO2 grade.

[0008] To achieve the above object, the present invention provides a method for extracting iron and reducing titanium from vanadium-titanium iron concentrate, which comprises the following steps:

[0009] A. Grinding the vanadium-titanium iron concentrate to obtain a grinding product I, wherein the fineness of the grinding product I is -0.043 mm ≥ 90%;

[0010] B. filtering, drying and breaking up the ground ore product I obtained in step A, and then mixing it with a calcium source to obtain a mixture; the calcium source is CaCO3 or CaO;

[0011] C. calcining the mixed material obtained in step B to obtain a calcined material;

[0012] D. Grinding the roasted material obtained in step C to obtain a grinding product II, wherein the fineness of the grinding product II is -0.043 mm ≥ 90%;

[0013] E. performing weak magnetic separation on the ore grinding product II obtained in step D to obtain weak magnetic separation concentrate and weak magnetic separation tailings;

[0014] F. Reverse flotation is performed on the weak magnetic separation tailings obtained in step E. The reverse flotation sediment is the reverse flotation concentrate, and the reverse flotation foam is the reverse flotation tailings. In the reverse flotation, the pH adjusting agent is H2SO4, the pH value is adjusted to 2-4, the collector is MOH, and the auxiliary collector is diesel;

[0015] G. The weak magnetic separation concentrate obtained in step E and the reverse flotation concentrate obtained in step F are combined into the final iron concentrate, and the reverse flotation concentrate obtained in step F is the final tailings.

[0016] Among them, in the method for extracting iron and reducing titanium from the above-mentioned vanadium-titanium iron concentrate, in step B, the weight ratio of CaCO3 to vanadium-titanium magnetite is 1-2:1-10; the weight ratio of CaO to vanadium-titanium magnetite is 1-1.5:1-10.

[0017] Wherein, in the above method for extracting iron and reducing titanium from vanadium-titanium iron concentrate, in step C, the roasting temperature is 600°C to 1200°C.

[0018] Wherein, in the above method for extracting iron and reducing titanium from vanadium-titanium iron concentrate, in step C, the roasting time is 4h to 12h.

[0019] Wherein, in the above method for extracting iron and reducing titanium from vanadium-titanium iron ore concentrate, in step E, the magnetic field strength of the weak magnetic separation is 1000Oe to 3500Oe.

[0020] Among them, in the method for extracting iron and reducing titanium from the above-mentioned vanadium-titanium iron concentrate, in step F, the amount of pH adjuster H2SO4 relative to the reverse flotation feed is 1000-4000 g / t, the amount of collector MOH relative to the reverse flotation feed is 1000-2000 g / t, and the amount of auxiliary collector diesel relative to the reverse flotation feed is 100-800 g / t.

[0021] Beneficial effects of the present invention:

[0022] The present invention roasts the vanadium-titanium iron concentrate with CaCO3 or CaO, so that Ti in the titanomagnetite is transferred from the titanomagnetite to perovskite or ferrous titanate, etc., which has a larger crystal particle size and is more conducive to grinding and dissociation; then, the various components in the roasted material are fully dissociated by grinding, and the weak magnetic separation process separates the strongly magnetic titanomagnetite from the weak magnetic mineral hematite and the non-magnetic mineral perovskite in the roasted material, so that the TFe grade in the vanadium-titanium iron concentrate is improved and the TiO2 grade is reduced; in addition, the flotation process separates the hematite from the ferrous titanate and perovskite in the weak magnetic separation tailings to obtain relatively pure hematite, which is incorporated into the iron concentrate to further improve the TFe grade in the vanadium-titanium iron concentrate and reduce the TiO2 grade. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0024] Specifically, a method for extracting iron and reducing titanium from vanadium-titanium iron concentrate comprises the following steps:

[0025] A. Grinding the vanadium-titanium iron concentrate (generally using an abrasive grinding machine or a tower mill) to obtain a grinding product I, wherein the fineness of the grinding product I is -0.043 mm ≥ 90%;

[0026] B. filtering, drying and breaking up the ground ore product I obtained in step A, and then mixing it with a calcium source to obtain a mixture; the calcium source is CaCO3 or CaO;

[0027] C. roasting the mixed material obtained in step B (roasting can be carried out by a microwave oven, a roasting furnace, a rotary kiln, etc.) to obtain a roasted material;

[0028] D. Grinding the roasted material obtained in step C (generally using an agar grinding machine or a tower mill) to obtain a grinding product II, wherein the fineness of the grinding product II is -0.043 mm ≥ 90%;

[0029] E. performing weak magnetic separation on the ore grinding product II obtained in step D to obtain weak magnetic separation concentrate and weak magnetic separation tailings;

[0030] F. Reverse flotation is performed on the weak magnetic separation tailings obtained in step E. The reverse flotation sediment is the reverse flotation concentrate, and the reverse flotation foam is the reverse flotation tailings. In the reverse flotation, the pH adjusting agent is H2SO4, and the pH value is adjusted to 2-4. The collector is MOH (MOH is an oxide ore collector, mainly a titanium oxide collector, which is a commercially available product), and the auxiliary collector is diesel;

[0031] G. The weak magnetic separation concentrate obtained in step E and the reverse flotation concentrate obtained in step F are combined into the final iron concentrate, and the reverse flotation concentrate obtained in step F is the final tailings.

[0032] The present invention roasts vanadium-titanium iron concentrate with CaCO3 or CaO, and the Ti in the titanomagnetite is transferred from the titanomagnetite to perovskite or iron titanate, etc., and the crystal size of perovskite (CaTiO3), hematite (Fe2O3), and iron titanate (Fe2TiO5) is larger, which is more conducive to grinding and dissociation. The specific reaction is:

[0033] Reaction ①FeTiO3+1 / 4O2(g)+CaCO3=1 / 2Fe2O3+CO2(g)+CaTiO3;

[0034] Reaction ②FeTiO3+1 / 4O2(g)=1 / 2Fe2O3+TiO2;

[0035] Reaction ③CaCO3+TiO2=CaTiO3+CO2(g);

[0036] Reaction ④Fe2O3+TiO2=Fe2TiO5.

[0037] The present invention does not use a mixture of CaCO3 and CaO, which is not conducive to the morphological transformation of Ti. In step B of the present invention, the weight ratio of CaCO3 to vanadium-titanium magnetite is 1-2:1-10; the weight ratio of CaO to vanadium-titanium magnetite is 1-1.5:1-10. The vanadium-titanium iron concentrate is ground, filtered, dried and dispersed, and the weight does not change before and after.

[0038] In step C of the present invention, the calcination temperature is 600° C. to 1200° C.; and the calcination time is 4 h to 12 h.

[0039] In step D of the present invention, the various components in the roasted material are fully dissociated by grinding, and the magnetic separation process separates the strongly magnetic titanium magnetite from the weakly magnetic mineral hematite (Fe2O3) and the non-magnetic mineral perovskite (CaTiO3) in the roasted material, thereby improving the TFe grade and reducing the TiO2 grade in the vanadium-titanium iron ore concentrate.

[0040] In step E of the present invention, the magnetic field strength of the weak magnetic separation is 1000Oe to 3500Oe.

[0041] In step F of the present invention, hematite (Fe2O3) is separated from iron titanate (Fe2TiO5) and perovskite (CaTiO3) in the magnetic tailings during the flotation process to obtain relatively pure hematite, which is incorporated into the magnetic concentrate to further improve the TFe grade in the vanadium-titanium iron concentrate and reduce the TiO2 grade. The material after roasting in the present invention has significant differences in properties from the original vanadium-titanium iron concentrate, so the present invention needs to adjust the reverse flotation. In reverse flotation, mainly due to the formation of perovskite, the flotation parameters are determined by flotation tests. In reverse flotation, the pH adjuster is H2SO4, and the pH value is adjusted to 2-4. The amount relative to the reverse flotation feed is 1000-4000g / t. The collector is MOH, and the amount relative to the reverse flotation feed is 1000-2000g / t. The auxiliary collector is diesel, and the amount relative to the reverse flotation feed is 100-800g / t. If the pH value is less than 2, it is difficult to remove the perovskite and reduce the titanium removal rate. If the pH value is neutral or even alkaline, the perovskite will float up together with the titanium magnetite, and the perovskite cannot be removed.

[0042] The present invention is further described in detail below by way of examples, but the protection scope of the present invention is not limited to the scope of the examples.

[0043] Example 1

[0044] The vanadium-titanium iron concentrate of the present embodiment comes from a place in Xichang, and its chemical composition is shown in Table 1.

[0045] Table 1 Chemical composition analysis of a vanadium-titanium iron concentrate

[0046] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO Grade / wt% 59.20 7.19 2.22 4.02 2.44 0.73

[0047] (1) Feed the vanadium-titanium iron concentrate into an abrasive mill or a tower mill for grinding, so that the fineness of the grinding product is -0.043mm≥95%;

[0048] (2) filtering, drying and breaking up the product of step (1), adding CaCO3 and vanadium-titanium iron concentrate and mixing them evenly, wherein the weight ratio of CaCO3 to vanadium-titanium magnetite is 2:8;

[0049] (3) The mixed product in step (2) is placed in a microwave oven for roasting at a temperature of 800° C. for 6 h;

[0050] (4) feeding the roasted material in step (3) into an agar grinding machine or a tower grinding machine for grinding, so that the fineness of the grinding product is -0.043 mm ≥ 95%;

[0051] (5) feeding the grinding product of step (4) into a weak magnetic separator for separation to obtain weak magnetic concentrate and tailings, the magnetic field strength being 3000 Oe;

[0052] (6) feeding the weak magnetic separation tailings in step (5) into a flotation machine for reverse flotation, wherein the pH adjusting agent is H2SO4, the pH value is adjusted to 3, and its dosage relative to the flotation feed is 3000 g / t, the collector is MOH, and its dosage relative to the flotation feed is 2000 g / t, and the auxiliary collector is diesel, and its dosage relative to the flotation feed is 400 g / t, the flotation foam is the tailings, and the flotation sand is the concentrate;

[0053] (7) combining the concentrates obtained in step (5) and step (6) into a final iron concentrate, and the tailings obtained in step (6) are the final tailings;

[0054] (8) According to the above steps, the final multi-element analysis indexes of iron ore concentrate can be obtained as shown in Table 2, and the specific separation effect can be obtained as shown in Table 3.

[0055] Table 2 Multi-element analysis results of the final iron concentrate of Example 1

[0056] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO grade / % 62.20 3.19 1.22 3.02 1.44 1.75

[0057] Table 3 Analysis results of separation effect of Example 1

[0058]

[0059] Example 2

[0060] The vanadium-titanium magnetite in this embodiment comes from a place in Panzhihua, and its floral composition is shown in Table 4.

[0061] Table 4 Chemical composition analysis of a vanadium-titanium iron concentrate

[0062] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO grade / % 53.76 13.11 3.12 4.09 4.14 0.97

[0063] (1) Feed the vanadium-titanium iron concentrate into an abrasive mill or a tower mill for grinding, so that the fineness of the grinding product is -0.043mm≥90%;

[0064] (2) filtering, drying and breaking up the product of step (1), adding CaO and mixing with vanadium-titanium iron concentrate in a weight ratio of CaO to vanadium-titanium magnetite of 1:10;

[0065] (3) The mixed product in step (2) is placed in a microwave oven for roasting at a temperature of 1000° C. for 8 h;

[0066] (4) feeding the roasted material in step (3) into an agar grinding machine or a tower grinding machine for grinding, so that the fineness of the grinding product is -0.043 mm ≥ 98%;

[0067] (5) feeding the grinding product of step (4) into a weak magnetic separator for separation to obtain weak magnetic concentrate and tailings, the magnetic field strength being 3500 Oe;

[0068] (6) Feed the weak magnetic separation tailings in step (5) into a flotation machine for reverse flotation, wherein the pH adjuster is H2SO4, the pH value is adjusted to 2, and its dosage relative to the flotation feed is 3000 g / t, the collector is MOH, and its dosage relative to the flotation feed is 2000 g / t, and the auxiliary collector is diesel, and its dosage relative to the flotation feed is 600 g / t, the flotation foam is the tailings, and the flotation sand is the concentrate;

[0069] (7) The concentrates obtained in step (5) and step (6) are combined into the final iron concentrate, and the tailings obtained in step (6) are the final tailings.

[0070] (8) According to the above steps, the final iron ore concentrate product indicators can be obtained as shown in Table 5, and the specific separation effect can be obtained as shown in Table 6.

[0071] Table 5 Multi-element analysis results of the final iron concentrate of Example 2

[0072] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO grade / % 60.76 5.11 2.15 2.08 3.14 2.58

[0073] Table 6 Analysis results of separation effect of Example 2

[0074]

[0075] The present invention roasts vanadium-titanium iron concentrate with CaCO3 or CaO, and uses chemical reaction to transform the chemical form of titanium, thereby changing the way of changing the physical form of titanium in traditional processes, thereby removing Ti isomorphously present in titanium magnetite and obtaining high TiO2 grade iron concentrate.

Claims

1. A method for increasing iron and reducing titanium from vanadium-titanium iron concentrate, characterized by: The following steps are involved: A. Grinding the vanadium-titanium iron concentrate to obtain a grinding product I, wherein the fineness of the grinding product I is -0.043 mm ≥ 90%; B. filtering, drying and breaking up the ground ore product I obtained in step A, and then mixing it with a calcium source to obtain a mixture; the calcium source is CaCO3 or CaO; C. calcining the mixed material obtained in step B to obtain a calcined material; D. Grinding the roasted material obtained in step C to obtain a grinding product II, wherein the fineness of the grinding product II is -0.043 mm ≥ 90%; E. performing weak magnetic separation on the ore grinding product II obtained in step D to obtain weak magnetic separation concentrate and weak magnetic separation tailings; F. Reverse flotation is performed on the weak magnetic separation tailings obtained in step E. The reverse flotation sediment is the reverse flotation concentrate, and the reverse flotation foam is the reverse flotation tailings. In the reverse flotation, the pH adjusting agent is H2SO4, the pH value is adjusted to 2-4, the collector is MOH, and the auxiliary collector is diesel; G. The weak magnetic separation concentrate obtained in step E and the reverse flotation concentrate obtained in step F are combined into the final iron concentrate, and the reverse flotation concentrate obtained in step F is the final tailings.

2. The method for extracting iron and reducing titanium from vanadium-titanium iron concentrate according to claim 1, characterized in that: In step B, the weight ratio of CaCO3 to vanadium-titanium magnetite is 1-2:1-10; the weight ratio of CaO to vanadium-titanium magnetite is 1-1.5:1-10.

3. The method for extracting iron and reducing titanium from vanadium-titanium iron concentrate according to claim 1, characterized in that: In step C, the calcination temperature is 600°C to 1200°C.

4. The method for extracting iron and reducing titanium from vanadium-titanium iron concentrate according to claim 1, characterized in that: In step C, the calcination time is 4 hours to 12 hours.

5. The method for extracting iron and reducing titanium from vanadium-titanium iron concentrate according to claim 1, characterized in that: In step E, the magnetic field strength of the weak magnetic separation is 1000Oe to 3500Oe.

6. The method for extracting iron and reducing titanium from vanadium-titanium iron concentrate according to any one of claims 1 to 5, characterized in that: In step F, the amount of pH adjuster H2SO4 relative to the reverse flotation feed is 1000-4000 g / t, the amount of collector MOH relative to the reverse flotation feed is 1000-2000 g / t, and the amount of auxiliary collector diesel relative to the reverse flotation feed is 100-800 g / t.

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