Method for recycling titanium concentrate from vanadium titano-magnetite iron dressing tailings

Abstract

The invention discloses a method for recycling titanium concentrate from vanadium titano-magnetite iron separation tailings, which comprises the following steps: S101, grading the iron separation tailings to obtain a coarse-grained titanium separation raw material and a fine-grained titanium separation raw material; s102, the coarse-grained titanium separation raw material is sequentially subjected to iron removal, reselection enrichment, dehydration and dry magnetic separation, and coarse-grained titanium concentrate, secondary iron and dry magnetic tailings are obtained; and S103, after the fine-particle-grade titanium separation raw material and the dry magnetic tailings are mixed, fine-particle flotation titanium concentrate is obtained after concentration iron removal, first-stage strong magnetic separation, ore grinding classification, second-stage iron removal and strong magnetic separation, flotation separation and filtering and drying treatment are conducted in sequence. According to the method disclosed by the invention, the reselection and dry magnetic separation processes with low energy consumption are adopted for about 60% of coarse-fraction materials through coarse-fine separation, so that the materials are prevented from entering an ore grinding flotation system with high energy consumption; and the fine fraction optimizes the ore grinding classification process, and the over-grinding energy consumption is reduced.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically relating to a method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite. Background Technology

[0002] The beneficiation process of vanadium-titanium magnetite typically begins with the recovery of iron concentrate through magnetic separation, resulting in tailings rich in ilmenite (TiO2 content generally ranges from 5.0% to 10.0%). Current technologies often employ a combined "two-stage high-intensity magnetic-flotation" or "high-intensity magnetic-gravity-flotation" process for titanium recovery from iron tailings.

[0003] The existing recycling process does not perform coarse and fine particle classification of tailings. Coarse titanium minerals are easily damaged by over-grinding, while fine titanium minerals have a low recovery rate due to insufficient separation. The process is complex and energy-intensive, especially the fine grinding and flotation of all materials, which leads to high production costs.

[0004] The existing recovery process involves full-scale flotation of ilmenite, which consumes a large amount of reagents. The titanium concentrate contains various residual flotation reagents, affecting the quality and cost of subsequent deep processing. Furthermore, the process fails to properly segment the flotation particle size range based on the particle size distribution characteristics of ilmenite in the tailings, thus failing to fully utilize the advantages of coarse-grained ilmenite. Fine grinding results in over-grinding and energy waste. Overall, there is still room for improvement in titanium recovery rate, and the final titanium concentrate product has a simple structure, making it difficult to meet the differentiated needs of various downstream industries for raw material particle size and quality.

[0005] Therefore, developing a recovery method that can accurately classify ilmenite in iron ore tailings based on its particle size characteristics, adopt differentiated sorting processes for different particle sizes, achieve low cost, high recovery rate, and produce diversified titanium concentrate products has become an urgent need in the current mineral processing field. Summary of the Invention

[0006] To address the shortcomings of the existing technology, a method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite is provided. This method can improve the comprehensive utilization level of vanadium-titanium magnetite tailings resources, reduce titanium resource recovery costs, and broaden the application scenarios of titanium concentrate products.

[0007] To achieve the above objectives, the following technical solution is adopted: This invention provides a method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite ore beneficiation. The iron tailings contain 5.0%-10.0 wt% TiO2 and the slurry has a mass concentration of 12%-25%. The method includes the following steps: S101. The iron tailings are classified to obtain coarse-grained titanium beneficiation raw material and fine-grained titanium beneficiation raw material. S102. The coarse-grained titanium raw material is sequentially subjected to iron removal, gravity separation enrichment, dehydration and dry magnetic separation to obtain coarse-grained titanium concentrate, secondary iron and dry magnetic tailings. S103. After mixing fine-grained titanium raw materials with dry magnetic tailings, the mixture is successively subjected to concentration and de-ironization, primary strong magnetic separation, grinding and classification, secondary de-ironization and strong magnetic separation, flotation separation, and filtration and drying to obtain fine-grained flotation titanium concentrate.

[0008] In some embodiments, in step S102, titanium middlings with a TiO2 content ≥38wt% are produced by gravity separation and enrichment, and the feed mass concentration of each spiral chute of gravity separation is 25%-40%.

[0009] In some embodiments, in step S102, the titanium middlings obtained by gravity separation are sequentially filtered and dried to dehydrate it to a moisture content of ≤0.50%; then the dried titanium middlings are subjected to iron removal treatment and then dry magnetic separation to obtain coarse titanium concentrate, secondary iron, and dry magnetic tailings; wherein, the TiO2 content of the coarse titanium concentrate is 46.0wt%-47.0wt%, and the content of particles with a particle size of -200 mesh is 25wt%-40wt%; the TiO2 content of the dry magnetic tailings is 11.0-14.0 wt%; and the secondary iron is returned to the iron beneficiation process of vanadium-titanium magnetite.

[0010] In some embodiments, the iron removal process in step S102, the concentration and iron removal in step S103, and the two-stage iron removal all employ a weak magnetic field separator with a magnetic field strength ranging from 2500 to 5000 Gs.

[0011] In some embodiments, in step S103, a first-stage strong magnetic separation is performed using a vertical ring pulsating high gradient strong magnetic separator, with a separation magnetic field strength ranging from 6000 to 13000 Gs, to obtain a first-stage strong magnetic concentrate.

[0012] In some embodiments, in step S103, the first-stage strong magnetic concentrate is ground and classified by a high-frequency fine screen, a classifying hydrocyclone and a ball mill to obtain a slurry; the slurry is then subjected to two stages of de-ironization and strong magnetic separation to obtain a second-stage strong magnetic concentrate.

[0013] In some embodiments, in step S103, the two-stage strong magnetic concentrate is concentrated to a mass concentration of 50%-58% and then subjected to flotation. The flotation separation is first subjected to desulfurization flotation, and then to titanium flotation to obtain flotation titanium concentrate and flotation tailings. The flotation titanium concentrate is filtered and dried to obtain fine-grained flotation titanium concentrate. The fine-grained flotation titanium concentrate has a TiO2 content of 46.0 wt%-47.0 wt% and a particle size of -200 mesh of 60 wt%-85 wt%. The flotation tailings have a TiO2 content of 3.5 wt%-4.5 wt% and a particle size of -200 mesh of 60 wt%-80 wt%.

[0014] In some embodiments, after adding water to adjust the pulp concentration to 25%-40%, the flotation tailings are returned to an independent spiral recovery system to obtain spiral concentrate; wherein, the spiral concentrate is recycled as a fine-grained titanium beneficiation feedstock.

[0015] In some embodiments, step S101, "classifying the iron ore tailings," includes: Iron tailings are transported to a flat-bottom hydrocyclone for primary classification to obtain hydrocyclone underflow and flat-bottom hydrocyclone overflow; the flat-bottom hydrocyclone overflow is fed into a plate thickener for secondary classification to obtain plate underflow and plate overflow; the hydrocyclone underflow and plate underflow are mixed according to particle size characteristics to be used as coarse-grained titanium beneficiation feedstock, and the plate overflow is used as fine-grained titanium beneficiation feedstock. Among them, the coarse-grained titanium beneficiation raw material has a particle size of -200 mesh and a particle content of 35%±5%, and the slurry mass concentration of the coarse-grained titanium beneficiation raw material is 25%-40%; the fine-grained titanium beneficiation raw material has a particle size of -200 mesh and a particle content of 85%±5%, and the slurry mass concentration of the fine-grained titanium beneficiation raw material is 20%-40%.

[0016] In some embodiments, the feed pressure of the flat-bottomed hydrocyclone in step S101 is 0.08-0.15 MPa.

[0017] According to the present invention, the application of coarse-grained titanium concentrate in the preparation of titanium dioxide or sponge titanium is also provided, wherein the coarse-grained titanium concentrate is obtained according to the method described above.

[0018] The present invention has the following beneficial technical effects: The method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite disclosed in this invention employs low-energy gravity separation and dry magnetic separation processes for the approximately 60% coarse-grained material, avoiding its entry into the high-energy-consuming grinding and flotation system. For the fine-grained stage, the grinding and classification process is optimized to reduce over-grinding energy consumption. Since no flotation reagents are required for the coarse-grained material, reagent consumption is reduced by 60%-80% compared to existing processes, achieving low-cost and high-efficiency recovery. The production cost using this method is approximately 25% lower than using a strong magnetic flotation process for all particle sizes. Attached Figure Description

[0019] 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.

[0020] Figure 1 A flowchart illustrating a method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the process flow for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite according to an embodiment of the present invention. Detailed Implementation

[0021] 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.

[0022] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0023] To achieve the above objectives, one aspect of the present invention provides a method for recovering titanium concentrate from iron ore tailings from vanadium-titanium magnetite beneficiation. The iron ore tailings contain 5.0%-10.0 wt% TiO2 and a slurry mass concentration of 12%-25%. Figure 1-2 The diagram shown is a schematic flowchart of the method.

[0024] like Figure 1 As shown, the preparation may include the following steps: S101. The iron tailings are classified to obtain coarse-grained titanium beneficiation raw material and fine-grained titanium beneficiation raw material. S102. The coarse-grained titanium raw material is sequentially subjected to iron removal, gravity separation enrichment, dehydration and dry magnetic separation to obtain coarse-grained titanium concentrate, secondary iron and dry magnetic tailings. S103. After mixing fine-grained titanium raw materials with dry magnetic tailings, the mixture is successively subjected to concentration and de-ironization, primary strong magnetic separation, grinding and classification, secondary de-ironization and strong magnetic separation, flotation separation, and filtration and drying to obtain fine-grained flotation titanium concentrate.

[0025] In a preferred embodiment of the present invention, in step S102, titanium middlings with a TiO2 content ≥38wt% are produced by gravity separation and enrichment, and the feed mass concentration of each spiral chute of gravity separation is 25%-40%.

[0026] In a preferred embodiment of the present invention, in step S102, the titanium middlings obtained by gravity separation are sequentially filtered and dried to dehydrate it to a moisture content of ≤0.50%; then the dried titanium middlings are subjected to iron removal treatment and then dry magnetic separation to obtain coarse titanium concentrate, secondary iron, and dry magnetic tailings; wherein, the TiO2 content of the coarse titanium concentrate is 46.0wt%-47.0wt%, and the content of particles with a particle size of -200 mesh is 25wt%-40wt%; the TiO2 content of the dry magnetic tailings is 11.0-14.0 wt%; and the secondary iron is returned to the iron beneficiation process of vanadium-titanium magnetite.

[0027] In a preferred embodiment of the present invention, the iron removal process in step S102, the concentration and iron removal in step S103, and the two-stage iron removal all employ a weak magnetic field separator with a magnetic field strength ranging from 2500 to 5000 Gs.

[0028] Specifically, in step S102, the coarse-grained titanium material is processed by separation: Coarse-grained iron removal: The coarse-grained titanium-selected material is subjected to iron removal treatment to remove strongly magnetic iron minerals; Gravity separation enrichment: The coarse-grained titanium-selected material after iron removal is fed into a gravity separation spiral system, where it is separated using a coarsening-scavenging-cleaning process to produce titanium middlings with a TiO2 content ≥38%. The feed concentration in each section of the spiral sluice is 25%-40%. For example, Figure 2 As shown, the process of roughing-scavenging-cleaning is as follows: First, the coarse-grained titanium material undergoes roughing to obtain rougher concentrate and rougher tailings. The rougher tailings are then scavenged to obtain scavenged concentrate, scavenged middlings, and scavenged tailings. The scavenged concentrate and rougher concentrate are mixed and fed into the primary cleaning stage to obtain primary concentrate, primary middlings, and primary tailings. The primary concentrate then enters the secondary cleaning stage to obtain secondary concentrate, secondary middlings, and secondary tailings. The secondary concentrate, which is the titanium middlings, is then subjected to subsequent dewatering and dry magnetic separation. The primary tailings are returned to the inclined plate for secondary concentration and classification. The secondary tailings are returned to the primary cleaning stage. The primary middlings are returned to the primary cleaning stage. The secondary middlings are returned to the secondary cleaning stage.

[0029] Dehydration and dry magnetic separation: The titanium middlings are filtered and dried sequentially to a moisture content of ≤0.50%; then the dried titanium middlings are de-ironized and fed into a dry magnetic separator for separation to obtain coarse titanium concentrate, secondary iron, and dry magnetic tailings; the TiO2 content of the coarse titanium concentrate is 46.0%-47.0%, and the -200 mesh content is 25%-40%; the secondary iron is returned to the iron beneficiation process, and the dry magnetic tailings are returned to the fine-grained titanium beneficiation process.

[0030] In a preferred embodiment of the present invention, in step S103, a first-stage strong magnetic separation is performed using a vertical ring pulsating high gradient strong magnetic separator, with a separation magnetic field strength ranging from 6000 to 13000 Gs, to obtain a first-stage strong magnetic concentrate.

[0031] In a preferred embodiment of the present invention, in step S103, the first-stage strong magnetic concentrate is ground and classified by a high-frequency fine screen, a classifying hydrocyclone and a ball mill to obtain a slurry; the slurry is then subjected to two stages of deironization and strong magnetic separation to obtain a second-stage strong magnetic concentrate.

[0032] In a preferred embodiment of the present invention, in step S103, the two-stage strong magnetic concentrate is concentrated to a mass concentration of 50%-58% and then subjected to flotation. The flotation separation is first subjected to desulfurization flotation, and then to titanium flotation to obtain flotation titanium concentrate and flotation tailings. The flotation titanium concentrate is filtered and dried to obtain fine-grained flotation titanium concentrate. The fine-grained flotation titanium concentrate has a TiO2 content of 46.0 wt%-47.0 wt% and a particle size of -200 mesh of 60 wt%-85 wt%. The flotation tailings have a TiO2 content of 3.5 wt%-4.5 wt% and a particle size of -200 mesh of 60 wt%-80 wt%.

[0033] In a preferred embodiment of the present invention, after adding water to adjust the slurry mass concentration to 25%-40%, the flotation tailings are returned to an independent spiral recovery to obtain spiral concentrate; wherein, the spiral concentrate is recycled as a fine-grained titanium beneficiation raw material.

[0034] Specifically, in step S103, the fine-grained titanium-selective material is processed by separation: Concentration and iron removal: After the concentrated fine-grained titanium-selected material is mixed evenly with dry magnetic tailings, iron removal treatment is carried out. First-stage high-intensity magnetic separation: The iron-removed slurry is fed into a first-stage high-intensity magnetic separator for separation, resulting in a first-stage high-intensity magnetic concentrate and a first-stage high-intensity magnetic tailings. The first-stage high-intensity magnetic tailings are discarded directly. Grinding and classification: A section of strong magnetic concentrate is fed into a grinding and classification system consisting of a high-frequency fine screen, a classifying hydrocyclone, and a ball mill. The process of "screening first, then classifying, and sand entering the mill" is adopted to obtain qualified particle size slurry. Two-stage iron removal and strong magnetic separation: After the qualified particle size slurry undergoes two-stage iron removal, it is fed into a periodic strong magnetic separator for separation to obtain two-stage strong magnetic concentrate and two-stage strong magnetic tailings; the separation magnetic field strength of the periodic strong magnetic separator ranges from 8000 to 15000 Gs, and the separation time is 3-5 min.

[0035] Flotation separation: The two-stage strong magnetic concentrate is concentrated to a concentration of 50%-58%, and then enters the flotation system; the flotation system sequentially performs desulfurization flotation and titanium flotation to obtain flotation titanium concentrate with a TiO2 content of 46.0%-47.0% and a -200 mesh content of 60%-85%; Flotation tailings recovery: Flotation tailings (TiO2 content of about 4%) are replenished with water to adjust the concentration to 25%-40% and returned to an independent spiral recovery. The spiral concentrate is then recovered as a fine-grained titanium beneficiation feedstock. Product processing: After concentration, filtration, drying and dehydration, the flotation titanium concentrate is used to obtain fine-grained flotation titanium concentrate product.

[0036] In a preferred embodiment of the present invention, step S101, "classifying the iron ore tailings," includes: Iron tailings are transported to a flat-bottom hydrocyclone for primary classification to obtain hydrocyclone underflow and flat-bottom hydrocyclone overflow; the flat-bottom hydrocyclone overflow is fed into a plate thickener for secondary classification to obtain plate underflow and plate overflow; the hydrocyclone underflow and plate underflow are mixed according to particle size characteristics to be used as coarse-grained titanium beneficiation feedstock, and the plate overflow is used as fine-grained titanium beneficiation feedstock. Among them, the coarse-grained titanium beneficiation raw material has a particle size of -200 mesh and a particle content of 35%±5%, and the slurry mass concentration of the coarse-grained titanium beneficiation raw material is 25%-40%; the fine-grained titanium beneficiation raw material has a particle size of -200 mesh and a particle content of 85%±5%, and the slurry mass concentration of the fine-grained titanium beneficiation raw material is 20%-40%.

[0037] Specifically, in step S101, tailings classification: a two-stage classification of "flat-bottom hydrocyclone + inclined plate thickener" is adopted. The tailings from the iron ore beneficiation process are transported to the flat-bottom hydrocyclone for primary classification, and the overflow from the hydrocyclone enters the inclined plate thickener for secondary classification. According to the particle size characteristics, they are divided into coarse-grained titanium beneficiation raw materials (hydrocyclone underflow + inclined plate underflow) and fine-grained titanium beneficiation raw materials (inclined plate overflow), avoiding mutual interference between coarse and fine particles and laying the foundation for subsequent accurate separation.

[0038] In a preferred embodiment of the present invention, the feed pressure of the flat-bottomed hydrocyclone in step S101 is 0.08-0.15 MPa.

[0039] The coarse-grained titanium concentrate obtained according to embodiments of the present invention is used in the preparation of titanium dioxide or sponge titanium.

[0040] The method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite disclosed in this invention employs low-energy gravity separation and dry magnetic separation processes for the approximately 60% coarse-grained material, avoiding its entry into the high-energy-consuming grinding and flotation system. For the fine-grained stage, the grinding and classification process is optimized to reduce over-grinding energy consumption. Since no flotation reagents are required for the coarse-grained material, reagent consumption is reduced by 60%-80% compared to existing processes, achieving low-cost and high-efficiency recovery. The production cost using this method is approximately 25% lower than using a strong magnetic flotation process for all particle sizes.

[0041] The present invention discloses a method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite. The coarse-grained material is recovered separately and efficiently, reducing the loss of titanium metal caused by over-grinding. At the same time, the dry magnetic separation tailings are returned to the fine-grained system for further recovery, realizing the comprehensive recovery of titanium resources. Through multi-stage iron removal, strong magnetic enrichment and recycling design, the titanium resource system recovery rate is increased to more than 40%, which is 5%-8% higher than the existing process.

[0042] The method for recovering titanium concentrate from iron tailings of vanadium-titanium magnetite disclosed in this invention produces coarse titanium concentrate with a large particle size and free of flotation reagents. It is a high-quality raw material for the production of titanium dioxide and sponge titanium, providing high-end raw materials for deep titanium processing, increasing product added value, and broadening product application scenarios. Fine flotation titanium concentrate can be used as a conventional product, meeting the diversified needs of the market.

[0043] The method of this invention features flexible process combinations, conventional equipment, and convenient operation and control, making it easy to promote and apply in existing mineral processing plants and demonstrating good industrial feasibility. The equipment selection is conventional, operation is simple and easy to control, and it can be adapted to iron ore tailings with different TiO2 contents (5.0 wt%-10.0 wt%), making it suitable for large-scale industrial application.

[0044] The present invention will be further illustrated by the following examples.

[0045] A vanadium-titanium magnetite beneficiation plant processes ore through a crushing system followed by three-stage grinding and three-stage magnetic separation to recover iron concentrate. The total tailings composition after iron beneficiation is approximately 7.8 wt% TiO2, approximately 10.5% TFe, and a slurry mass concentration of approximately 17%. The method of this invention is used for titanium recovery, and the specific steps are as follows: S1. Tailings Classification: The tailings from the iron ore beneficiation process are fed into a flat-bottom hydrocyclone at a feed pressure of 0.10 MPa for classification. The hydrocyclone underflow and the underflow from the inclined plate thickener are combined to form coarse-grained titanium beneficiation material (approximately 35% -200 mesh content, slurry mass concentration of 25%-40%). The overflow from the inclined plate thickener is used as fine-grained titanium beneficiation material (approximately 85% -200 mesh content).

[0046] S2, Processing of coarse-grained titanium-selective materials: S2a, Coarse-grained iron removal: Coarse-grained titanium-selected materials are de-ironized by a weak magnetic separator with a magnetic field strength of 4000 Gs. The secondary iron ore is returned to the iron-selection system. The magnetic iron content of the material after iron removal is controlled to be less than 0.5%.

[0047] S2b, Gravity Concentration: After iron removal, the material is fed into the gravity separation spiral system. After a roughing, scavenging and three-finishing process, titanium middlings with a TiO2 content of 38.5% are obtained. The gravity separation spiral tailings with a grade of less than 2.5% are discarded.

[0048] S2c, Dehydration and Dry Magnetic Separation: After the gravity-separated titanium ore is filtered and dried to a moisture content of 0.45%, it is de-ironized again and then fed into a dry magnetic separator for separation (one coarse and one fine) to obtain coarse titanium concentrate (TiO2 content 46.8 wt%, -200 mesh content about 32%), which can be sold directly as a product; the secondary iron ore from the dry de-ironization is returned to the iron beneficiation system, and the tailings from the dry magnetic separation (TiO2 content 12.5 wt%) are returned to the fine-grained titanium beneficiation system.

[0049] S3, Fine-grained titanium selective material processing: S3a. Concentration and iron removal: Fine-grained titanium-selected material is fed into a thickener and concentrated to a concentration of about 30%. After being mixed with dry magnetic tailings, it is de-ironized by a weak magnetic separator (magnetic field strength 3500Gs). The magnetic iron content of the material after iron removal is controlled to be within 0.5%.

[0050] S3b, First-stage strong magnetic separation: The de-iron ore slurry is fed into a vertical ring pulsating high gradient strong magnetic separator (magnetic field strength 10000Gs) for separation, resulting in a first-stage strong magnetic concentrate (TiO2 content 12.2 wt%) and a first-stage strong magnetic tailings (TiO2 content 1.90 wt%, discarded).

[0051] S3c, Grinding and Classification: The first-stage strong magnetic concentrate is fed into the grinding and classification system. The newly fed material is first conveyed to the high-frequency fine screen (screen size 0.15mm + 0.18mm combination) for screening and classification. The undersize material is qualified and enters the next process. The oversize material and the ball mill discharge are collected together and fed into the classifying hydrocyclone. The overflow of the hydrocyclone is returned to the high-frequency fine screen, and the undersize sand is fed into the ball mill by gravity. Finally, qualified particle size slurry with -200 mesh accounting for 78% is obtained.

[0052] S3d, Second-stage iron removal and strong magnetic separation: Qualified particle size slurry is fed into a weak magnetic separator (magnetic field strength 4000Gs) for iron removal. The magnetic iron content of the material after the second-stage iron removal is controlled within 0.35%, and the secondary iron ore is returned to the iron beneficiation system. Then, it is fed into a periodic strong magnetic separator (magnetic field strength 12000Gs, separation time 4min) to obtain a second-stage strong magnetic concentrate (TiO2 content 20.3 wt%) and a second-stage strong magnetic tailings (TiO2 content 2.6 wt%, discarded).

[0053] S3e, Flotation Separation: The two-stage strong magnetic concentrate is concentrated to a concentration of 52% by a thickener and then enters the flotation system. First, desulfurization flotation is carried out (one roughing and three scavenging processes + desliming process, desulfurization reagents: xanthate, pine oil, sulfuric acid), and then titanium flotation is carried out (one roughing, three scavenging and four cleaning processes, reagents: fatty acid collectors, diesel, sulfuric acid, sodium fluorosilicate, etc.), to obtain flotation titanium concentrate (TiO2 content ≥ 46.5 wt%) and flotation tailings (TiO2 content about 3.5 wt%).

[0054] S3f, Recycling of Flotation Tailings: The coarse-grained portion of the flotation tailings has a high grade. The flotation tailings are diluted with water to reduce the concentration to about 25%, and then separated and recycled using a first-stage gravity separation spiral sluice. The spiral concentrate grade is about 6%, and it is returned to the first-stage strong magnetic pre-iron removal operation. The spiral tailings (TiO2 content about 2.5 wt%) are discarded.

[0055] S4. Processing of flotation titanium concentrate: After being processed by a filtration and drying system, the moisture content of the flotation titanium concentrate is controlled to within 0.50%, resulting in fine-grained flotation titanium concentrate product.

[0056] This embodiment ultimately yields two qualified products: coarse-grained titanium concentrate and fine-grained flotation titanium concentrate. The coarse-grained titanium concentrate accounts for approximately 65% ​​of the total titanium concentrate yield, and its production cost is reduced by about 25% compared to using a strong magnetic-flotation process for all particle sizes. The total system recovery rate of titanium reaches 41.2%, an improvement of approximately 5.5 percentage points compared to the original single fine-grained recovery process. Due to its unique physicochemical properties, the coarse-grained titanium concentrate can be sold at a premium as a high-quality raw material.

[0057] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. 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 number.

[0058] 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 different aspects of the invention 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 recovering titanium concentrate from iron tailings of vanadium-titanium magnetite ore beneficiation, characterized in that, The iron tailings ore contains 5.0%-10.0 wt% TiO2 and the slurry mass concentration is 12%-25%. The method includes the following steps: S101. The iron tailings are classified to obtain coarse-grained titanium beneficiation raw material and fine-grained titanium beneficiation raw material. S102. The coarse-grained titanium raw material is sequentially subjected to iron removal, gravity separation enrichment, dehydration and dry magnetic separation to obtain coarse-grained titanium concentrate, secondary iron and dry magnetic tailings. S103. After mixing fine-grained titanium raw materials with dry magnetic tailings, the mixture is successively subjected to concentration and de-ironization, primary strong magnetic separation, grinding and classification, secondary de-ironization and strong magnetic separation, flotation separation, and filtration and drying to obtain fine-grained flotation titanium concentrate.

2. The method according to claim 1, characterized in that, In step S102, the titanium middlings with a TiO2 content ≥38wt% are produced by gravity separation and enrichment. The feed mass concentration of each spiral chute section of the gravity separation is 25%-40%.

3. The method according to claim 2, characterized in that, In step S102, the titanium middlings obtained by gravity separation are sequentially filtered and dried to dehydrate, so that the moisture content of the titanium middlings is ≤0.50%. Then, the dried titanium middlings are subjected to iron removal treatment and then dry magnetic separation to obtain coarse titanium concentrate, secondary iron, and dry magnetic tailings. Among them, the TiO2 content of the coarse titanium concentrate is 46.0wt%-47.0wt%, and the content of particles with a particle size of -200 mesh is 25wt%-40wt%. The TiO2 content of the dry magnetic tailings is 11.0-14.0wt%. The secondary iron is returned to the iron beneficiation process of vanadium-titanium magnetite.

4. The method according to claim 1, characterized in that, The iron removal process in step S102, the concentration and iron removal in step S103, and the two-stage iron removal all use a weak magnetic field separator with a magnetic field strength range of 2500-5000 Gs.

5. The method according to claim 1, characterized in that, In step S103, a first-stage strong magnetic separation is carried out using a vertical ring pulsating high gradient strong magnetic separator with a separation magnetic field strength range of 6000-13000Gs, resulting in a first-stage strong magnetic concentrate.

6. The method according to claim 5, characterized in that, In step S103, the first-stage strong magnetic concentrate is ground and classified by a high-frequency fine screen, a classifying hydrocyclone, and a ball mill to obtain a slurry; the slurry is then subjected to two stages of de-ironization and strong magnetic separation to obtain a second-stage strong magnetic concentrate.

7. The method according to claim 6, characterized in that, In step S103, the two-stage strong magnetic concentrate is concentrated to a mass concentration of 50%-58% and then subjected to flotation. The flotation separation is first carried out by desulfurization flotation, and then by titanium flotation to obtain flotation titanium concentrate and flotation tailings. The flotation titanium concentrate is filtered and dried to obtain fine-grained flotation titanium concentrate. The fine-grained flotation titanium concentrate has a TiO2 content of 46.0 wt%-47.0 wt% and a particle size of -200 mesh of 60 wt%-85 wt%. The flotation tailings have a TiO2 content of 3.5 wt%-4.5 wt% and a particle size of -200 mesh of 60 wt%-80 wt%.

8. The method according to claim 7, characterized in that, After adding water to adjust the pulp concentration to 25%-40%, the flotation tailings are returned to an independent spiral recovery system to obtain spiral concentrate; the spiral concentrate is then recycled as a fine-grained titanium beneficiation feedstock.

9. The method according to claim 1, characterized in that, Step S101, "classifying the iron ore tailings," includes: Iron tailings are transported to a flat-bottom hydrocyclone for primary classification to obtain hydrocyclone underflow and flat-bottom hydrocyclone overflow; the flat-bottom hydrocyclone overflow is fed into an inclined plate thickener for secondary classification to obtain inclined plate underflow and inclined plate overflow; the hydrocyclone underflow and inclined plate underflow are mixed according to particle size characteristics to be used as coarse-grained titanium beneficiation feedstock, and the inclined plate overflow is used as fine-grained titanium beneficiation feedstock. Among them, the coarse-grained titanium beneficiation raw material has a particle size of -200 mesh of 35%±5% and a slurry mass concentration of 25%-40%; the fine-grained titanium beneficiation raw material has a particle size of -200 mesh of 85%±5% and a slurry mass concentration of 20%-40%. The feed pressure of the flat-bottomed hydrocyclone is 0.08-0.15 MPa.

10. The application of a coarse-grained titanium concentrate in the preparation of titanium dioxide or sponge titanium, characterized in that, The coarse-grained titanium concentrate is obtained by the method according to any one of claims 1-9.

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