Comprehensive utilization method of vanadium titano-magnetite tailings

Abstract

The invention discloses a comprehensive utilization method of vanadium titano-magnetite tailings, and belongs to the technical field of mineral separation. In order to achieve comprehensive utilization of iron and titanium in magnetic vanadium titano-magnetite tailings, the comprehensive utilization method for the vanadium titano-magnetite tailings comprises the steps that the vanadium titano-magnetite tailings are subjected to low-intensity magnetic separation I, and low-intensity magnetic concentrate I and low-intensity magnetic tailings I are obtained; after the weak magnetic concentrate I is subjected to ball milling, weak magnetic separation II is conducted, and iron concentrate and weak magnetic tailings II are obtained; the weak magnetic tailings II are combined to overflow for flotation I; the weak magnetic tailings I are subjected to strong magnetic separation, and strong magnetic concentrates and strong magnetic tailings are obtained; performing cyclone classification on the strong magnetic concentrate to obtain overflow and settled sand, and performing flotation I and flotation II on the overflow and the settled sand respectively to obtain titanium concentrate I and titanium concentrate II. The vanadium titano-magnetite tailings are subjected to graded flotation, iron ore concentrate with the TFe grade being larger than or equal to 58% and titanium concentrate with the TiO2 grade being 42% or above and titanium concentrate with the TiO2 grade being 47% or above can be obtained, and comprehensive utilization of the vanadium titano-magnetite tailings is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ore dressing, and particularly relates to a comprehensive utilization method for vanadium-titanium magnetite tailings. Background Art

[0002] Vanadium-titanium magnetite is a ferrous metal ore containing various useful metal elements such as iron, titanium, and vanadium. It is not only an important source of iron but also associated with various trace elements, having high comprehensive utilization value. In small ore dressing plants, after primary crushing and grinding, gravity separation equipment such as spiral chutes and conical ore dressing machines are mainly used for rough separation, and then shaking tables are used for fine separation. This method can obtain high-grade titanium concentrate, but the recovery rate is not high, and the TiO2 grade of the tailings is high. The average TiO2 grade of this kind of tailings is above 10%, the ilmenite is fine, and the specific gravity difference between ilmenite and gangue minerals is small, making it difficult to effectively utilize by gravity separation methods. Therefore, for this vanadium-titanium magnetite tailings, a process flow of first separating iron and then classifying and flotation separating titanium is adopted. Classifying flotation reduces the covering effect of fine-grained minerals on coarse-grained ilmenite, and at the same time, fine-grained ilmenite is utilized.

[0003] CN20191024631.1 discloses a process for recycling vanadium-titanium magnetite tailings. It uses a heavy magnetic separation machine for preselection, and then a closed-circuit grinding - weak magnetic separation method to obtain iron concentrate. The weak magnetic tailings are preselected and discarded by a spiral chute, and the spiral chute concentrate is subjected to three-stage shaking table separation for titanium. This method can obtain iron concentrate with an Fe grade of 60.0%, a TiO2 content of 4.21%, an Fe recovery rate of 29.0%, and a TiO2 recovery rate of 5.6%, as well as titanium concentrate with an Fe grade of 30.23%, a TiO2 content of 45.0%, an Fe recovery rate of 10.02%, and a TiO2 recovery rate of 41.5%. This method uses a spiral chute and a shaking table for all-size separation of titanium without classification treatment, and the gravity separation equipment has a large floor area and low efficiency.

[0004] CN20231015696.1 discloses a beneficiation method for recovering ilmenite from vanadium-titanium magnetite total tailings. The vanadium-titanium magnetite total tailings are classified into sand sediment 1 with a particle size of +0.15mm, sand sediment 2 with a particle size of +0.038mm, and overflow with a particle size of -0.075mm; sand sediment 1 and sand sediment 2 are preselected and discarded by a spiral chute. When the grinding of the preselected concentrate reaches 85% of the content of -0.074mm, weak magnetic separation is carried out to obtain iron rough concentrate and weak magnetic tailings; the overflow is subjected to strong magnetic rough separation once, strong magnetic fine separation twice, and strong magnetic scavenging once. The weak magnetic tailings and the strong magnetic concentrate are combined into pre-enriched concentrate, and then flotation is carried out to obtain titanium concentrate. This method can obtain titanium concentrate with a TiO2 grade ≥ 48% and a TiO2 overall process recovery rate ≥ 40%. This method uses gravity separation, magnetic separation, and classification pre-enrichment, and all-size flotation separation of titanium for the pre-enriched concentrate, without comprehensively utilizing the magnetite in the ore.

[0005] CN20241140818.4 discloses a process for separating ilmenite from the iron tailings of olivine pyroxene type low-grade vanadium-titanium magnetite ore. The iron tailings of olivine pyroxene type low-grade vanadium-titanium magnetite ore are subjected to stage grinding and stage separation using a pulsating high-gradient magnetic separator to obtain titanium rough concentrate and tailings; the titanium rough concentrate is subjected to flotation desulfurization using a one-roughing-one-scavenging-four-cleaning or one-roughing-two-scavenging-four-cleaning process to obtain sulfur-cobalt concentrate and desulfurized tailings; the desulfurized tailings are subjected to flotation for titanium separation using a one-roughing-one-scavenging-three-cleaning or one-roughing-two-scavenging-four-cleaning process to obtain titanium concentrate. In this method, the grade of titanium concentrate can reach about 47%, and the TiO2 recovery rate reaches about 55%. This method performs strong magnetic pre-concentration and flotation for titanium separation on the iron tailings of olivine pyroxene type low-grade vanadium-titanium magnetite ore, and the particle size of the material is coarse. Summary of the Invention

[0006] The object of the present invention is to realize the comprehensive recovery and utilization of iron and titanium in the tailings of magnetic vanadium-titanium magnetite, and to obtain iron concentrate with high grade and high recovery rate, and titanium concentrate with high grade and high recovery rate by a relatively simple beneficiation method.

[0007] To achieve the above object, the present invention provides a method for comprehensive utilization of vanadium-titanium magnetite tailings, which comprises the following steps:

[0008] The vanadium-titanium magnetite tailings are subjected to weak magnetic separation I using a wet drum magnetic separator to obtain weak magnetic concentrate I and weak magnetic tailings I; the weak magnetic concentrate I is ground to a fineness of -0.038mm content ≥ 95% using a wet ball mill, and then subjected to weak magnetic separation II using a wet drum magnetic separator to obtain iron concentrate and weak magnetic tailings II;

[0009] The weak magnetic tailings I are subjected to one-stage strong magnetic rough separation using a wet high-gradient strong magnetic separator to obtain strong magnetic rough concentrate and strong magnetic rough tailings. The strong magnetic rough concentrate is further subjected to one-stage strong magnetic scavenging to obtain strong magnetic scavenging concentrate and strong magnetic scavenging tailings. The strong magnetic rough concentrate and the strong magnetic scavenging concentrate are combined as strong magnetic concentrate, and the strong magnetic scavenging tailings are the strong magnetic tailings. The strong magnetic concentrate is subjected to hydrocyclone classification to obtain overflow product and sand product;

[0010] The weak magnetic tailings II and the overflow product are combined, and after desulfurization, they are subjected to flotation I for ilmenite separation to obtain titanium concentrate I and flotation I tailings; the sand product is desulfurized and then subjected to flotation II for ilmenite separation to obtain titanium concentrate II and flotation II tailings; the flotation I tailings and the flotation II tailings are combined as total tailings; fatty acid reagent is used as the collector for ilmenite in flotation I and flotation II, sulfuric acid is used as the regulator, and oxalic acid and sodium silicate are used as inhibitors in flotation I.

[0011] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the vanadium-titanium magnetite tailings are the iron tailings separated by magnetic separation of vanadium-titanium magnetite or the titanium tailings separated by gravity separation of vanadium-titanium magnetite. Its TiO₂ grade is 10% - 15%, S content < 0.3%, magnetite content is 3% - 25%, and the content of -0.038mm is 55% - 75%. The particle size of this tailings is too fine, resulting in the mud in it circulating in the flotation system, covering the ilmenite minerals, thus affecting the flotation of ilmenite, the grade of titanium concentrate, and at the same time increasing the acid consumption and cost. Therefore, the present invention optimizes the beneficiation process for this tailings, classifies and recovers coarse and fine particles. Through experiments, it is found that selecting the sand content of -0.038mm to be 30% - 35% is the best value to reduce the influence of fine particle size and slime on the flotation of easily separable coarse-grained ilmenite.

[0012] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the magnetic field intensity of the weak magnetic separation I is 1500 - 1800 Gs.

[0013] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the magnetic field intensity of the weak magnetic separation II is 1300 - 1500 Gs.

[0014] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the TFe grade of the iron concentrate ≥ 58%, and the Fe recovery rate ≥ 20%.

[0015] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the magnetic field intensity of the first-stage strong magnetic separation roughing is 6000 - 8500 Gs, and the magnetic field intensity of the first-stage strong magnetic separation scavenging is 6000 - 8500 Gs.

[0016] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, when controlling the cyclone classification, the sand product content of -0.038mm is 30% - 35%.

[0017] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, the flotation I is a sequential return closed-circuit process, including one roughing, four cleanings, and two scavengings. The tailings of the concentrate in the four cleanings and the scavenging concentrate in the two scavengings are sequentially returned to the previous operation for re-flotation;

[0018] Among them, in the above comprehensive utilization method of vanadium-titanium magnetite tailings, in the flotation I, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 during roughing, the dosage of the roughing collector is 2200 - 2500 g / t, the dosage of the roughing inhibitor oxalic acid is 200 - 350 g / t, the dosage of sodium silicate is 100 - 200 g / t. Sulfuric acid is used to adjust the pH value to 2.5 - 3.5 during cleaning, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 during scavenging. The dosage of the scavenging collector is 400 - 500 g / t.

[0019] Among them, in the above method for comprehensive utilization of vanadium-titanium magnetite tailings, the second flotation is a sequential return closed-circuit process, which includes one roughing, three cleaning, and two scavenging operations. The tailings of the concentrate in the three cleaning operations and the scavenging concentrate in the two scavenging operations are sequentially returned to the previous operation for re-flotation;

[0020] Among them, in the above method for comprehensive utilization of vanadium-titanium magnetite tailings, in the second flotation, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 during roughing, and the dosage of the roughing collector is 1900 - 2200 g / t. Sulfuric acid is used to adjust the pH value to 2.5 - 3.5 during cleaning, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 during scavenging. The dosage of the scavenging collector is 400 - 500 g / t.

[0021] Among them, in the above method for comprehensive utilization of vanadium-titanium magnetite tailings, the TiO₂ grade of the first titanium concentrate is above 42%, and the TiO₂ recovery rate is ≥20%.

[0022] Among them, in the above method for comprehensive utilization of vanadium-titanium magnetite tailings, the TiO₂ grade of the second titanium concentrate is above 47%, and the TiO₂ recovery rate is ≥35%.

[0023] In the present invention, after the second weak magnetic tailings and the overflow product are combined for desulfurization, and the sand product is desulfurized, the conventional one-roughing and one-scavenging process in the art is used for desulfurization.

[0024] Advantages of the present invention:

[0025] Aiming at magnetic and gravity separation tailings with TiO₂ content of 10% - 15%, S content < 0.3%, magnetite content of 3% - 25%, and -0.038 mm content of 55% - 75%, the present invention uses a method combining weak magnetic separation, strong magnetic separation, classification, and flotation to recover iron and titanium. According to the characteristics of the tailings, different flotation processes are used for the overflow and sand to perform classification flotation, obtaining iron concentrate with TFe grade ≥58%, and obtaining two grades of titanium concentrate with TiO₂ grade above 42% and above 47%, realizing the comprehensive utilization of vanadium-titanium magnetite tailings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic flow chart of the comprehensive utilization of vanadium-titanium magnetite tailings of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described in detail below through examples, but the protection scope of the present invention is not limited to the scope of the described examples.

[0028] Example 1

[0029] Indexes of vanadium-titanium magnetite tailings: TiO₂ grade 11.02%, S content 0.21%, magnetite content 20.12%, -0.038 mm content 72.67%.

[0030] The tailings are subjected to weak magnetic separation I using a wet drum magnetic separator under a magnetic field intensity of 1800 Gs to obtain weak magnetic concentrate I and weak magnetic tailings I; the obtained weak magnetic concentrate I is ground in a wet ball mill to a fineness of 98% passing -0.038 mm, and then subjected to weak magnetic separation II using a wet drum magnetic separator under a magnetic field intensity of 1500 Gs to obtain iron concentrate with a TFe grade of 58.21% and an Fe recovery rate of 21.55% and weak magnetic tailings II; the weak magnetic tailings II are combined with the overflow for flotation I.

[0031] The obtained weak magnetic tailings I are subjected to rough selection of one-stage strong magnetic separation using a wet high-gradient strong magnetic separator under a magnetic field intensity of 7500 Gs, and the tailings of the rough selection of strong magnetic separation are subjected to one-stage strong magnetic scavenging under a magnetic field intensity of 8500 Gs. The concentrate of the rough selection of strong magnetic separation and the concentrate of the strong magnetic scavenging are combined into strong magnetic concentrate, and the tailings of the strong magnetic scavenging are the strong magnetic tailings; the strong magnetic concentrate is subjected to hydrocyclone classification to obtain overflow product and sand product. The sand product has a content of 33% passing -0.038 mm. The overflow product and the weak magnetic tailings II are combined and desulfurized before flotation I to obtain titanium concentrate I, and the sand product is desulfurized before flotation II to obtain titanium concentrate II.

[0032] Flotation I is a sequential return closed-circuit process, including one rough selection, four concentrate selections, and two scavenging selections in sequence. The tailings of the concentrate in the four concentrate selections and the scavenged concentrate in the two scavenging selections are sequentially returned to the previous operation for re-flotation; in flotation I, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 in the rough selection, the dosage of fatty acid reagent as the collector in the rough selection is 2500 g / t, the dosage of oxalic acid as the inhibitor in the rough selection is 300 g / t, and the dosage of sodium silicate is 200 g / t. Sulfuric acid is used to adjust the pH value to 2.5 - 3.5 in the concentrate selection, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 in the scavenging selection. The dosage of fatty acid reagent as the collector in the scavenging selection is 500 g / t. Flotation II is a sequential return closed-circuit process, including one rough selection, three concentrate selections, and two scavenging selections in sequence. The tailings of the concentrate in the three concentrate selections and the scavenged concentrate in the two scavenging selections are sequentially returned to the previous operation for re-flotation; in flotation II, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 in the rough selection, the dosage of fatty acid reagent as the collector in the rough selection is 2100 g / t, sulfuric acid is used to adjust the pH value to 2.5 - 3.5 in the concentrate selection, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 in the scavenging selection. The dosage of fatty acid reagent as the collector in the scavenging selection is 425 g / t.

[0033] Titanium concentrate I: TiO2 grade 45.67%, TiO2 recovery rate 21.52%; Titanium concentrate II: TiO2 grade 47.28%, TiO2 recovery rate 38.65%.

[0034] Example 2

[0035] Different from Example 1, the indexes of vanadium-titanium magnetite tailings are as follows: TiO2 grade is 13.99%, S content is 0.19%, magnetite content is 7.59%, and the content of -0.038mm is 55.97%. The magnetic field intensity of weak magnetic separation I is 1600 Gs, and that of weak magnetic separation II is 1350 Gs. Iron concentrate with a TFe grade of 58.02% and an Fe recovery rate of 20.12% is obtained. The magnetic field intensity of the first-stage strong magnetic roughing is 6500 Gs, and that of the first-stage strong magnetic scavenging is 8000 Gs. The content of -0.038mm in the sand product is 34%. In flotation I, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 during roughing. The dosage of fatty acid collector in roughing is 2300 g / t, the dosage of oxalic acid inhibitor in roughing is 200 g / t, and the dosage of sodium silicate is 100 g / t. Sulfuric acid is used to adjust the pH value to 2.5 - 3.5 during cleaning, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 during scavenging. The dosage of fatty acid collector in scavenging is 460 g / t. In flotation II, sulfuric acid is used to adjust the pH value to 3.5 - 4.0 during roughing. The dosage of fatty acid collector in roughing is 1950 g / t. Sulfuric acid is used to adjust the pH value to 2.5 - 3.5 during cleaning, and sulfuric acid is used to adjust the pH value to 3.5 - 4.5 during scavenging. The dosage of fatty acid collector in scavenging is 390 g / t.

[0036] Ilmenite concentrate I: TiO2 grade is 43.90%, and TiO2 recovery rate is 20.72%; Ilmenite concentrate II: TiO2 grade is 47.15%, and TiO2 recovery rate is 40.79%.

[0037] It can be seen that for vanadium-titanium magnetite tailings with a -0.038mm content of 50% - 75%, the present invention uses a combined method of weak magnetic separation, strong magnetic separation, classification, and flotation to recover iron and titanium. According to the characteristics of the tailings, different flotation processes are used for the overflow and sand products for classification flotation, obtaining iron concentrate with a TFe grade ≥ 58%, and two kinds of ilmenite concentrates with a TiO2 grade above 42% and above 47%, realizing the comprehensive utilization of vanadium-titanium magnetite tailings.

Claims

1. A method for comprehensive utilization of vanadium-titanium magnetite tailings, characterized in that: The following steps are involved: The tailings of vanadium-titanium magnetite are subjected to weak magnetic separation I by using a wet drum magnetic separator to obtain weak magnetic concentrate I and weak magnetic tailings I; The weak magnetic concentrate I is ground by a wet ball mill to a fineness of -0.038 mm and a content of ≥95%, and then weak magnetic separation II is performed by a wet drum magnetic separator to obtain iron concentrate and weak magnetic tailings II; The weak magnetic tailings I are subjected to a stage of strong magnetic roughing separation by a wet high-gradient strong magnetic separator to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings. The strong magnetic roughing concentrate is subjected to a stage of strong magnetic scavenging separation to obtain a strong magnetic scavenging concentrate and a strong magnetic scavenging tailings. The strong magnetic roughing concentrate and the strong magnetic scavenging concentrate are combined into a strong magnetic concentrate. The strong magnetic scavenging tailings are the strong magnetic tailings. The strong magnetic concentrate is subjected to cyclone classification to obtain an overflow product and a grit product. The weak magnetic tailings II and overflow products are combined, desulfurized, and then flotation I is carried out to select ilmenite to obtain titanium concentrate I and flotation I tailings; after the desulfurization of the sedimentation product, flotation II is carried out to select ilmenite to obtain titanium concentrate II and flotation II tailings; the flotation I tailings and flotation II tailings are combined to form the total tailings; flotation I and flotation II use fatty acid reagents as ilmenite collectors and sulfuric acid as adjusters, and flotation I uses oxalic acid and sodium silicate as inhibitors.

2. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: The vanadium-titanium magnetite tailings are vanadium-titanium magnetite magnetic iron tailings or vanadium-titanium magnetite gravity titanium tailings, with a TiO2 grade of 10% to 15%, an S content of less than 0.3%, a magnetite content of 3% to 25%, a fineness of -0.038 mm and a content of 55% to 75%.

3. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: The magnetic field strength of the weak magnetic separation I is 1500-1800 Gs.

4. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: The magnetic field strength of the weak magnetic separation II is 1300-1500 Gs.

5. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: The TFe grade of the iron concentrate is ≥58%, and the Fe recovery rate is ≥20%.

6. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: The magnetic field strength of the roughing stage of the strong magnetic separation is 6000-8500 Gs, and the magnetic field strength of the sweeping stage of the strong magnetic separation is 6000-8500 Gs.

7. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: When controlling the cyclone classification, the content of sand settling product -0.038mm is 30% to 35%.

8. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: At least one of the following is met: Flotation I is a closed-circuit process with sequential return, including one roughing, four concentrates and two scavenging. The concentrate tailings in the four concentrates and the scavenged concentrate in the two scavenging are returned to the previous operation for refloatation. In flotation I, sulfuric acid is used to adjust the pH value to 3.5-4.0 in roughing, 2200-2500 g / t of collector is used in roughing, 200-350 g / t of oxalic acid as inhibitor is used in roughing, and 100-200 g / t of sodium silicate is used in roughing. Sulfuric acid is used to adjust the pH value to 2.5-3.5 in fine separation, and sulfuric acid is used to adjust the pH value to 3.5-4.5 in scavenging, and 400-500 g / t of collector is used in scavenging.

9. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to claim 1, characterized in that: At least one of the following is met: Flotation II is a closed-circuit process with sequential return, including primary roughing, tertiary concentration and secondary scavenging. The concentrate tailings in the tertiary concentration and the scavenged concentrate in the secondary scavenging are returned to the previous operation for refloatation. In flotation II, sulfuric acid is used to adjust the pH value to 3.5-4.0 in roughing, and the amount of collector used in roughing is 1900-2200 g / t. Sulfuric acid is used to adjust the pH value to 2.5-3.5 in fine separation, and sulfuric acid is used to adjust the pH value to 3.5-4.5 in scavenging, and the amount of collector used in scavenging is 400-500 g / t.

10. The method for comprehensive utilization of vanadium-titanium magnetite tailings according to any one of claims 1 to 9, characterized in that: The TiO2 grade of the titanium concentrate I is above 42%, and the TiO2 recovery rate is ≥20%; the TiO2 grade of the titanium concentrate II is above 47%, and the TiO2 recovery rate is ≥35%.

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