Method for recovering micro-fine particle grade titanium middlings

Abstract

The invention relates to the technical field of mineral product treatment, in particular to a method for recycling micro-fine particle grade titanium middling, which comprises the steps of size mixing, high-gradient vertical ring strong magnetic one-coarse and one-fine desliming, concentration hopper concentration, laminated high-frequency vibration fine screen grading, flat plate type magnetic separation secondary concentration, inclined plate concentration, disc type filtration and the like. Key parameters are quantified and controlled through five creative formula algorithms such as ore pulp concentration calculation and magnetic field intensity optimization. Tailings with the titanium grade being 3.0-3.5% and the-200-mesh proportion being larger than or equal to 50% are selected as raw materials, and micro-fine particle grade titanium middling products with the titanium grade being 35-40%, the yield being 1.4-2.8% and the water content being smaller than or equal to 11% can be obtained after treatment. The method does not need flotation reagents, meets the environmental protection requirement, is high in resource recovery efficiency, wide in process adaptability and easy to operate, achieves tailing resource utilization, has remarkable economic and environmental benefits and is easy to industrially popularize.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, specifically a method for recovering fine-grained titanium ore. Background Technology

[0002] Titanium, a strategic metal with excellent properties such as high strength, corrosion resistance, and high temperature resistance, is widely used in many key fields such as aerospace, chemical industry, metallurgy, and new energy, and is an important basic material supporting the development of modern industry. my country is a major titanium resource country with abundant and widely distributed titanium ore reserves, mainly divided into three types: ilmenite placer deposits, ilmenite rock deposits, and rutile rock deposits. Among them, ilmenite placer deposits have become the main type of titanium ore development and utilization in my country due to their advantages such as low mining difficulty, relatively simple beneficiation process, and controllable production costs.

[0003] Yunnan Province, as one of the core producing areas of ilmenite placer deposits in my country, boasts particularly outstanding titanium resources, with over 30 proven ilmenite deposits, including 15 large deposits. The reserves of high-quality ilmenite exceed 32,650 kt, mainly concentrated in six major areas: Wuding, Luquan, Mile, and Dali. The ore is characterized by high grade and ease of mining, possessing excellent development prospects. However, due to strict environmental protection policies in Yunnan, most mines have not constructed dedicated tailings ponds, generally adopting tailings pressure filtration and backfilling as the treatment method. Even concentrators with tailings ponds cannot use flotation processes for titanium ore separation due to restrictions on reagent use, forcing local concentrators to rely on gravity separation equipment such as spiral sluices and shaking tables for mineral processing.

[0004] While traditional gravity separation processes are simple to operate and have low energy consumption, they have significant technical limitations: their core separation principle relies on the density difference between minerals and gangue, resulting in good separation of larger minerals (+200 mesh), but extremely low recovery efficiency for fine-grained minerals (-200 mesh). Field investigations revealed that the raw ilmenite sand deposits in Yunnan are highly weathered, with generally fine particle sizes. In most mines, particles smaller than 0.074 mm (-200 mesh) account for over 50% of the raw ore, with some mines even exceeding 80%. However, after processing with traditional gravity separation, the final titanium concentrate produced only contains ≤5% particles smaller than 0.074 mm. This means that a large amount of recoverable fine-grained ilmenite is directly lost in the tailings, causing serious waste of titanium resources and resulting in low yields and economic losses for the beneficiation plant. Furthermore, the large-scale stockpiling or backfilling of tailings poses potential environmental risks and land resource occupation problems, contradicting the industry trend of green and efficient utilization of mineral resources. Therefore, developing a technical solution that adapts to Yunnan's environmental protection policy requirements, requires no flotation reagents, and can efficiently recover fine-grained ilmenite from tailings has become a key technical challenge that the Yunnan ilmenite sand mining industry urgently needs to solve. Summary of the Invention

[0005] The purpose of this invention is to provide a method for recovering fine-grained titanium ore, in order to solve the problems mentioned in the background art, such as the difficulty in recovering fine-grained titanium ore from tailings of existing ilmenite sand mines in Yunnan, the low yield, and the inability to use flotation processes due to environmental restrictions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for recovering fine-grained titanium ore includes the following steps:

[0008] Step S1: Take a tailings sample from the total tailings or spiral tailings of the ilmenite sand beneficiation plant. The tailings slurry has good dispersibility and no agglomeration after grinding or stirring. The particle size distribution is ≥50% of -200 mesh. Add water and stir to adjust the slurry.

[0009] Step S2: The well-mixed slurry is introduced into a high-gradient vertical ring strong magnetic separator for roughing operation to obtain roughing concentrate and roughing tailings. The roughing tailings are incorporated into the total tailings discharge of the original process.

[0010] Step S3: After mixing the roughing concentrate, it is fed into a high-gradient vertical ring strong magnetic separator for fine separation to obtain fine concentrate and fine tailings. The fine tailings are then fed into the strong magnetic roughing feed.

[0011] Step S4: The selected concentrate is fed into the thickening hopper for thickening treatment, resulting in the thickening hopper bottom flow and the thickening hopper overflow;

[0012] Step S5: The bottom flow of the concentration hopper is introduced into a stacked high-frequency vibrating fine screen for grading to obtain oversize material and undersize material. The oversize material is returned to the original spiral separation process, and the undersize material is introduced into a flat magnetic separator.

[0013] Step S6: The undersize material is further refined using a flat-plate magnetic separator to obtain flat-plate concentrate slurry and flat-plate tailings slurry. The flat-plate tailings are then introduced into the refining operation in step S3.

[0014] Step S7: The flat plate concentrate slurry is introduced into the inclined plate thickener for thickening to obtain the inclined plate underflow and the inclined plate overflow. The inclined plate overflow is connected to the total tailings.

[0015] Step S8: The underflow from the inclined plate is introduced into a disc filter for filtration to obtain fine-grained titanium middlings product;

[0016] The high-gradient vertical ring strong magnetic separator forms a coarse-fine desliming process. The thickening hopper is connected to the fine vertical ring strong magnetic separator and the stacked high-frequency vibrating fine screen. The flat plate magnetic separator is connected in sequence to the stacked high-frequency vibrating fine screen and the inclined plate thickener. The disc filter is connected to the inclined plate thickener.

[0017] In step S1, the pulp concentration is calculated using the following formula and controlled between 15% and 35%:

[0018] ×100%;

[0019] in, The concentration of the slurry is expressed as a percentage (%). The dry mass (kg) of the tailings sample. The amount of water added is measured in kg. During the slurry preparation process, the water addition amount is adjusted by real-time detection of the slurry density to ensure that the concentration deviation is ≤ ±1%.

[0020] Preferably, the sorting magnetic field strength of the high-gradient vertical ring strong magnetic coarse separation operation in step S2 is determined to be 1-1.3T using the following optimization formula:

[0021] ;

[0022] in, The magnetic field strength (T) is used for rough selection. The percentage of -200 mesh particles in the tailings sample is given. The spacing between the media boxes of the vertical ring strong magnet is fixed at 2 mm, and the slurry flow rate is controlled at 0.8-1.2 m / s.

[0023] Preferably, the sorting magnetic field strength and the spacing between dielectric cells in the high-gradient vertical ring strong magnetic sorting operation in step S3 satisfy the following correlation algorithm:

[0024] ;

[0025] in, To select the optimal magnetic field strength, the range is 0.7-1.0T. To determine the titanium grade of the roughing concentrate, The distance between media boxes is in mm, and the distance between media boxes is fixed at 1 mm. The residence time of the slurry in the fine separation operation is 1.5-2 times that in the roughing operation.

[0026] Preferably, the concentration of the concentrate bottom flow in step S4 is adjusted to 30-35% using the following control formula:

[0027] ;

[0028] in, To concentrate the bottom flow concentration, The concentration of the feed to the concentration hopper. The residence time of the slurry in the thickening tank, in minutes. The concentration efficiency coefficient is set at 0.9-1.05. The concentration hopper adopts an intermediate feeding method, and the overflow rate is controlled at 0.3-0.5 m³ / h.

[0029] Preferably, the screening efficiency of the stacked high-frequency vibrating fine screen in step S5 satisfies the following calculation formula, and the screening efficiency is ≥80%:

[0030] ;

[0031] in, Screening efficiency (%) The mass (kg) of particles with a size > 0.074 mm in the undersize material. The feed contains particles with a size >0.074mm (kg); the screen aperture is 0.074mm; the screening area of ​​the equipment is 8.75㎡; the vibration frequency is 1500r / min; anti-clogging and wear-resistant polyurethane screens are used; and the single-layer stacked screen processing capacity is ≤5t / h.

[0032] Preferably, the recovery rate of ilmenite by the flat-plate magnetic separator in step S6 is calculated using the following model, and the recovery rate is ≥75%:

[0033]

[0034] in, The recovery rate of ilmenite is %. The titanium grade (%) is the feed material to the flat-plate magnetic separator. Titanium grade (%) of plate concentrate. The titanium grade of the flat plate tailings is (%); the feed concentration of the flat plate magnetic separator is 30-40%, the surface magnetic field is 7000GS, and auxiliary water supply such as waterfall water and concentrate unloading water is set, with the water flow rate controlled at 0.2-0.3m / s.

[0035] Preferably, the underflow concentration of the inclined plate thickener in step S7 is controlled to be 40-60% using the following optimization algorithm:

[0036]

[0037] in, The concentration of the underflow at the slab is (%). The density of ilmenite is (g / cm³). This represents the volume (m³) of solid particles in the flat concentrate slurry. This is the particle packing factor (values ​​range from 0.6 to 0.7). The density of water (g / cm³). The volume (m³) of water in the plate concentrate slurry is given. The inclination angle of the inclined plate thickener is 60-65°.

[0038] Preferably, the product moisture content of the disc filter in step S8 is controlled to be ≤11% using the following formula:

[0039] ;

[0040] in, Moisture content of the product (%) This refers to the feed throughput (t / h). The filter area (㎡) is fixed at 5㎡. The filtration pressure (MPa) is controlled within the range of 0.3-0.5MPa. The titanium grade of the fine-grained titanium ore after filtration is 35%-40%, and the yield is 1.4-2.8%.

[0041] Preferably, the overflow of the thickening hopper is connected to the underflow outlet of the stacked high-frequency vibrating fine screen; the concentrate outlet of the flat magnetic separator is connected to the inlet of the inclined plate thickener; the tailings outlet of the flat magnetic separator is connected to the inlet of the high-gradient vertical ring strong magnetic separator; and the underflow of the inclined plate thickener is connected to the inlet of the disc filter. When the underflow concentration calculated in step S7 is less than 40%, a portion of the underflow is returned to the inlet of the inclined plate thickener for re-concentration via a reflux device. The reflux ratio is determined according to the concentration deviation using a formula. Calculation determined.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] (1) This invention addresses the pain point of the difficulty in recovering large amounts of fine-grained ilmenite from tailings in Yunnan ilmenite sand mines. It adopts a combined process of high-gradient vertical ring strong magnetic separation for coarse and fine desliming, stacked high-frequency vibrating fine screening, and plate magnetic separation for secondary cleaning, breaking through the technical bottleneck of poor recovery effect of traditional gravity separation processes for -200 mesh fine-grained minerals. By precisely controlling key indicators such as magnetic field strength, slurry concentration, and screening parameters, and combining five sets of creative formula algorithms to achieve quantitative optimization of parameters in each process, tailings with a titanium grade of only 3.0-3.5% can be transformed into fine-grained titanium middlings products with a titanium grade of 35%-40% and a yield of 1.4-2.8%, which greatly reduces the waste of titanium resources, creates additional economic benefits for the beneficiation plant, and reduces the environmental pressure caused by tailings stockpiling.

[0044] (2) This invention adopts magnetic separation technology throughout the entire process, eliminating the need for flotation reagents and completely avoiding the environmental restrictions and restrictions on reagent use in tailings ponds in Yunnan Province. The process has no harmful pollutant emissions, which is in line with the development trend of green mineral processing. At the same time, the process has a wide adaptability to raw materials and can handle different types of tailings with a -200 mesh ratio of 50%-80%. The material on the screen can be returned to the original spiral separation process, and the selected tailings and plate tailings can be recycled for gravity separation, forming a closed-loop recovery system, which effectively reduces the load of subsequent separation while improving resource utilization. The equipment selection takes into account both high efficiency and economy. The stacked high-frequency vibrating fine screen has the advantages of high screening efficiency, low energy consumption and small footprint, while the plate magnetic separator has a large selection area and high separation accuracy. The whole process is simple to operate and easy to promote industrially.

[0045] (3) This invention constructs a quantitative control system for all process parameters by introducing formulas for calculating slurry concentration, optimizing magnetic field strength, calculating screening efficiency, modeling ilmenite recovery rate, and controlling product moisture content. This achieves precise control of each stage from slurry preparation to filtration, avoiding the index fluctuation problem caused by relying on experience in traditional processes. For example, the magnetic field strength formula for roughing is used to dynamically adjust the magnetic field parameters according to the tailings particle size distribution, ensuring that fine-grained ilmenite is fully adsorbed. The recovery rate model is used to monitor the separation effect in real time and optimize the operating parameters in a timely manner, so that the ilmenite recovery rate is stable at over 75%. In addition, the process organically integrates units such as magnetic separation, grading, concentration, and filtration. The connection between each piece of equipment is close, and the design of oversize material and tailings recirculation further enhances the overall integrity and efficiency of the process. Its technical solution has significant novelty and creativity, providing a new and reliable solution for the recovery of fine-grained ilmenite. Attached Figure Description

[0046] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are explained in detail together with the embodiments of the invention, but do not constitute a limitation thereof.

[0047] Figure 1 This is a system composition block diagram of the present invention;

[0048] Figure 2 This is a bar chart comparing key data from three embodiments of the present invention. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0050] like Figure 1 As shown, this invention provides a method for recovering fine-grained titanium ore, which achieves efficient recovery of fine-grained ilmenite from tailings through a combination process mainly based on magnetic separation. The following is a detailed description:

[0051] 1. Raw material pretreatment and equipment preparation

[0052] Raw material selection: The total tailings or spiral tailings of the ilmenite sand beneficiation plant are selected as raw materials. The raw materials must meet the following requirements: good dispersibility after grinding or stirring, no particle agglomeration, -200 mesh accounting for ≥50% of the particle size distribution, and initial titanium grade of 3.0-3.5%.

[0053] Equipment selection and commissioning:

[0054] High-gradient vertical ring strong magnetizer: It adopts electromagnetic magnetic field type, and the medium box spacing can be switched between 1mm and 2mm specifications. The magnetic field strength adjustment range is 0.5-1.5T, ensuring precise magnetic field control for coarse and fine selection operations.

[0055] Concentrator: It adopts a central feeding structure with an effective volume of ≥5m³ and is equipped with an online concentration detection device to monitor the underflow concentration in real time.

[0056] Stacked high-frequency vibrating fine screen: The screen aperture is 0.074mm, the screening area is 8.75㎡, the vibration frequency is fixed at 1500r / min, the screen is made of anti-clogging and wear-resistant polyurethane material, and the single-layer stacked screen processing capacity is controlled to ≤5t / h.

[0057] Flat plate magnetic separator: permanent magnet type, with a surface magnetic field strength of 7000GS, equipped with waterfall water and concentrate unloading water system, and the water flow speed can be adjusted to 0.2-0.3m / s.

[0058] Inclined plate thickener: tilt angle 60-65°, equipped with underflow concentration control system, and supports underflow reflux device.

[0059] Disc filter: filtration area 5㎡, filtration pressure adjustment range 0.3-0.5MPa, equipped with moisture detection device.

[0060] 2. Specific Implementation Steps

[0061] Step 1: Slurry preparation

[0062] Take a quantitative tailings sample and apply it according to the slurry concentration formula. Calculate the required amount of clean water to add by multiplying by 100%. For tailings dry quality, To ensure the quality of the clean water, the tailings and clean water are mixed and stirred to adjust the slurry concentration, which is controlled at 15%-35%. During the slurry preparation process, the slurry density is monitored in real time using a densitometer to adjust the amount of clean water added, ensuring that the concentration deviation is ≤±1% and avoiding concentration fluctuations from affecting the subsequent separation effect.

[0063] Step 2: High-gradient vertical ring strong magnetic coarse separation

[0064] The uniformly mixed slurry is introduced into a high-gradient vertical ring magnetic separator, based on the proportion of -200 mesh particles in the tailings. By roughly selecting the magnetic field strength formula The separation magnetic field strength was determined to be 1-1.3T, the media box spacing was set to 2mm, and the slurry flow rate was controlled to be 0.8-1.2m / s. After separation, rougher concentrate and rougher tailings were obtained. The rougher tailings were directly incorporated into the original process total tailings discharge to avoid ineffective materials occupying the processing load of subsequent equipment.

[0065] Step 3: High-gradient vertical ring strong magnetic selection

[0066] After the roughing concentrate is stirred and mixed, it is introduced into a high-gradient vertical ring magnetic separator for further refining, based on the titanium grade of the roughing concentrate. and media box spacing (Fixed to 1mm), using a carefully selected magnetic field strength correlation algorithm The separation magnetic field strength is determined to be 0.7-1.0T. The slurry residence time for the fine separation operation is set to 1.5-2 times that for the roughing operation to ensure sufficient adsorption and separation of fine-grained ilmenite. After separation, fine concentrate and fine tailings are obtained. The fine tailings are returned to the feed inlet of the strong magnetic roughing separation for re-separation to improve the resource recovery rate.

[0067] Step 4: Concentrate using a concentration chamber

[0068] The selected concentrate is fed into the thickening hopper using an intermediate feed method, and the concentration is controlled by the underflow concentration formula. Adjusting the residence time of the slurry in the thickening tank and concentration efficiency coefficient (0.9-1.05) to stabilize the underflow concentration in the thickener hopper at 30-35%. During the thickening process, monitor the overflow rate and control it at 0.3-0.5 m³ / h. The overflow from the thickener hopper is then combined with the underflow from the subsequent stacked high-frequency vibrating fine screen.

[0069] Step 5: Classification by stacked high-frequency vibrating fine screen

[0070] The concentrated flow from the bottom of the hopper is introduced into a multi-layer high-frequency vibrating fine screen for grading. The grading efficiency is determined using the formula... The screening efficiency is calculated in real time to ensure that the efficiency is ≥80%. After grading, the oversize material (particle size > 0.074mm) is returned to the original spiral separation process to separate coarse ilmenite, while the undersize material (particle size ≤ 0.074mm) is introduced into a flat plate magnetic separator for secondary refining.

[0071] Step 6: Secondary fine selection using flat-plate magnetic separation

[0072] Adjust the feed concentration of the plate magnetic separator to 30-40%, start the waterfall water and concentrate unloading water system, and control the water flow velocity to 0.2-0.3 m / s. Utilize the ilmenite recovery rate model. Calculate the recovery rate, ensuring it is ≥75%, where To determine the grade of the titanium feedstock, For the titanium grade of flat plate concentrate, The titanium grade of the flat plate tailings is determined. After separation, flat plate concentrate slurry and flat plate tailings slurry are obtained. The flat plate tailings are returned to the finer processing step 3 for reprocessing.

[0073] Step 7: Concentrate using an inclined plate concentrator

[0074] Flat-plate concentrate slurry is introduced into an inclined plate thickener, and the underflow concentration is optimized using an algorithm. Adjusting the concentration parameters, including the density of ilmenite. The density of water Particle packing coefficient Control the underflow concentration at 40-60%. If the underflow concentration is below 40%, adjust the recirculation ratio using the formula. Calculate the reflux ratio, return a portion of the underflow to the feed inlet of the inclined plate thickener for re-concentration, and combine the overflow of the inclined plate thickener into the total tailings discharge.

[0075] Step 8: Disc filter filtration

[0076] The underflow from the inclined plate is introduced into the disc filter, and the filtration pressure is set to 0.3-0.5 MPa. The product moisture content is controlled using the formula. Adjust the feed rate Ensure that the moisture content of the filtered product is ≤11% (where the filtration area is ≤11%). After filtration, fine-grained titanium middlings ore is obtained, with a titanium grade of 35%-40% and a yield of 1.4-2.8%.

[0077] The following three examples with different initial conditions further illustrate the specific implementation effects of the present invention. All examples are strictly operated according to the specific implementation methods described above. The raw material parameters, operating parameters, and product indicators of each set of examples are as follows:

[0078] Example 1

[0079] Raw material parameters: Spiral tailings from an ilmenite sand ore beneficiation plant, with 50% -200 mesh particles, initial titanium grade of 3.0%, and tailings dry weight... It exhibits good dispersion and no aggregation.

[0080] Operating parameter calculation and setting:

[0081] Step 1: Prepare the slurry according to the formula. ×100%, with a set slurry concentration of 20%, the amount of clean water added is calculated. The actual concentration after slurry preparation was 19.8%, with a deviation of ≤±1%.

[0082] Step 2: Preliminary selection based on the formula The value is revised to the 1.3T (upper limit) specified in the claims, with a media box spacing of 2mm and a slurry throughput speed of 1.0m / s.

[0083] Step 3: Fine Refinement: Titanium Grade of Rough Concentrate Medium cell spacing According to the formula The value was revised to 0.7T (lower limit), and the pulp residence time was 1.5 times that of the roughing process.

[0084] Step 4 Concentration: Concentration of Selected Concentrate Feed Set the stay time Concentration efficiency coefficient According to the formula By extending the residence time to 60 minutes, the final underflow concentration was 30.2%.

[0085] Step 5: Screening: Mass of particles with a size > 0.074 mm in the feed. The mass of particles with a size > 0.074 mm in the undersize material. According to the formula It meets the requirement of ≥80%.

[0086] Step 6: Flat plate magnetic separation: feed titanium grade Titanium grade of flat plate concentrate Titanium grade of flat plate tailings According to the formula It meets the requirement of ≥75%.

[0087] Step 7 Inclined Plate Concentration: Volume of solid particles in flat plate concentrate slurry The volume of water , =4.7g / cm³, according to the formula It meets the requirement of 40-60%.

[0088] Step 8 Filtration: Set the feed rate Filtration pressure According to the formula The actual moisture content after filtration is 6.5%.

[0089] Product specifications: Fine-grained titanium ore product weight 14.2kg, titanium grade 38.2%, yield 1.42%, moisture 6.5%, which meets the scope defined in the claims.

[0090] Example 2

[0091] Raw material parameters: The raw material is total tailings from an ilmenite sand ore beneficiation plant, with 65% being -200 mesh particles, an initial titanium grade of 3.2%, and tailings dry weight... After being stirred, it is evenly dispersed.

[0092] Operating parameter calculation and setting:

[0093] Step 1: Slurry preparation: Set the slurry concentration to 25%, according to the formula... ×100% to calculate the amount of clean water added. The actual concentration after slurry preparation was 25.3%, with a deviation of ≤±1%.

[0094] Step 2: Preliminary selection based on the formula The value was revised to 1.3T (upper limit), the media box spacing was 2mm, and the slurry throughput speed was 0.9m / s.

[0095] Step 3: Fine Refinement: Titanium Grade of Rough Concentrate Medium cell spacing According to the formula The value was adjusted to 0.85T (intermediate value), and the pulp residence time was 1.8 times that of the roughing process.

[0096] Step 4 Concentration: Concentration of Selected Concentrate Feed Set the stay time Concentration efficiency coefficient According to the formula The residence time was adjusted to 55 minutes, and the final underflow concentration was 32.6%.

[0097] Step 5: Screening: Mass of particles with a size > 0.074 mm in the feed. The mass of particles with a size > 0.074 mm in the undersize material. According to the formula The requirements are met.

[0098] Step 6: Flat plate magnetic separation: feed titanium grade Titanium grade of flat plate concentrate Titanium grade of flat plate tailings According to the formula The requirements are met.

[0099] Step 7 Inclined Plate Concentration: Volume of solid particles in flat plate concentrate slurry The volume of water , =4.7g / cm³, according to the formula The requirements are met.

[0100] Step 8 Filtration: Set the feed rate Filtration pressure According to the formula The actual moisture content after filtration was 6.2%.

[0101] Product specifications: Fine-grained titanium ore product weight 21.5kg, titanium grade 39.2%, yield 2.15%, moisture 6.2%, which meets the scope defined in the claims.

[0102] Example 3

[0103] Raw material parameters: Spiral tailings from an ilmenite sand ore beneficiation plant, with 80% -200 mesh particles, initial titanium grade of 3.5%, and tailings dry weight... It exhibits excellent dispersibility after grinding.

[0104] Operating parameter calculation and setting:

[0105] Step 1: Slurry preparation: Set the slurry concentration to 30%, according to the formula... ×100% to calculate the amount of clean water added. The actual concentration after slurry preparation was 29.7%, with a deviation of ≤±1%.

[0106] Step 2: Preliminary selection based on the formula The value was revised to 1.3T (upper limit), the media box spacing was 2mm, and the slurry throughput speed was 0.8m / s.

[0107] Step 3: Fine Refinement: Titanium Grade of Rough Concentrate Medium cell spacing According to the formula The value was revised to 1.0T (upper limit), and the slurry residence time was 2.0 times that of the roughing process.

[0108] Step 4 Concentration: Concentration of Selected Concentrate Feed Set the stay time Concentration efficiency coefficient According to the formula The residence time was adjusted to 60 minutes, and the final underflow concentration was 34.8%.

[0109] Step 5: Screening: Mass of particles with a size > 0.074 mm in the feed. The mass of particles with a size > 0.074 mm in the undersize material. According to the formula The requirements are met.

[0110] Step 6: Flat plate magnetic separation: feed titanium grade Titanium grade of flat plate concentrate Titanium grade of flat plate tailings According to the formula The requirements are met.

[0111] Step 7 Inclined Plate Concentration: Volume of solid particles in flat plate concentrate slurry The volume of water According to the formula The requirements are met.

[0112] Step 8 Filtration: Set the feed rate Filtration pressure According to the formula The actual moisture content after filtration was 6.0%.

[0113] Product specifications: Fine-grained titanium ore product weight 27.8kg, titanium grade 39.8%, yield 2.78%, moisture 6.0%, which meets the scope defined in the claims.

[0114] Example verification conclusions

[0115] The three sets of examples respectively cover typical operating conditions where the proportion of -200 mesh in the raw materials is 50%, 65%, and 80%, with an initial titanium grade of 3.0-3.5%. After processing by the method of the present invention, all yielded fine-grained titanium ore products with a titanium grade of 35%-40%, a yield of 1.4-2.8%, and a moisture content of ≤11%, verifying the stability and effectiveness of the method of the present invention. Simultaneously, the application of formula algorithms in each step ensures precise control of operating parameters, achieving efficient recovery of fine-grained ilmenite and solving the technical problem of poor recovery of fine-grained minerals in existing gravity separation processes.

[0116] The method for recovering fine-grained titanium ore according to the present invention has the following advantages:

[0117] This invention addresses the challenge of recovering large quantities of fine-grained ilmenite from tailings in Yunnan ilmenite sand mines. It employs a combined process of high-gradient vertical ring strong magnetic separation for coarse and fine desliming, layered high-frequency vibrating screen classification, and plate-type magnetic separation for secondary cleaning. This overcomes the technical bottleneck of traditional gravity separation processes, which suffer from poor recovery of -200 mesh fine-grained minerals. By precisely controlling key indicators such as magnetic field strength, slurry concentration, and screening parameters, and combining five sets of innovative formula algorithms to quantitatively optimize parameters at each stage, tailings with a titanium grade of only 3.0-3.5% can be transformed into fine-grained titanium middlings with a titanium grade of 35%-40% and a yield of 1.4-2.8%. This significantly reduces titanium resource waste, generates additional economic benefits for the concentrator, and simultaneously reduces the environmental pressure caused by tailings storage.

[0118] This invention employs magnetic separation throughout the entire process, eliminating the need for flotation reagents and completely circumventing environmental restrictions and contraindications related to reagent use in tailings ponds in Yunnan Province. The process generates no harmful pollutants, aligning with the trend of green mineral processing. Furthermore, the process is highly adaptable to various raw materials, handling tailings with a -200 mesh content of 50%-80%. Oversize material can be returned to the original spiral separator process, while refined tailings and plate-type tailings can be recycled for gravity separation, forming a closed-loop recovery system. This effectively reduces the load on subsequent separation processes while improving resource utilization. The equipment selection balances efficiency and economy. The stacked high-frequency vibrating fine screen offers advantages such as high screening efficiency, low energy consumption, and small footprint, while the plate-type magnetic separator provides a large selection area and high separation accuracy. The entire process is simple to operate and easy to industrialize.

[0119] This invention constructs a quantitative control system for all process parameters by introducing formulas for slurry concentration calculation, magnetic field strength optimization, screening efficiency calculation, ilmenite recovery rate model, and product moisture control. This system achieves precise control of each stage from slurry preparation to filtration, avoiding the performance fluctuations caused by reliance on experience in traditional processes. For example, the magnetic field strength formula for coarse separation dynamically adjusts the magnetic field parameters based on the tailings particle size distribution, ensuring sufficient adsorption of fine-grained ilmenite. The recovery rate model allows for real-time monitoring of the separation effect, enabling timely optimization of operating parameters and maintaining a stable ilmenite recovery rate above 75%. Furthermore, the process organically integrates magnetic separation, grading, concentration, and filtration units, with close connections between equipment. The design for oversize material and tailings recirculation further enhances the overall integrity and efficiency of the process. Its technical solution possesses significant novelty and creativity, providing a new and reliable solution for the recovery of fine-grained ilmenite.

[0120] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method of recovering fine fraction titanium middlings, characterized in that, The method comprises the following steps: Step S1: taking a tailing sample from ilmenite ore dressing plant total tailings or spiral tailings, the tailing slurry is well dispersed after grinding or stirring treatment without agglomeration phenomenon, the particle size distribution of-200 mesh accounts for ≥50%, and clear water is added for stirring and pulp preparation; Step S2: the mixed and uniform slurry is introduced into a high gradient vertical ring strong magnetic machine for roughing operation to obtain roughing concentrate and roughing tailings, and the roughing tailings are discharged into the original process total tailings; Step S3: the roughing concentrate is stirred and mixed uniformly and then introduced into the high gradient vertical ring strong magnetic machine for cleaning operation to obtain cleaning concentrate and cleaning tailings, and the cleaning tailings are introduced into the strong magnetic roughing feed; Step S4: the cleaning concentrate is introduced into a thickener for thickening treatment to obtain thickener underflow and thickener overflow; Step S5: the thickener underflow is introduced into a stacked high-frequency vibration fine screen for classification operation to obtain screen oversize and screen undersize, and the screen oversize is returned to the original spiral separation process, and the screen undersize is introduced into a flat plate magnetic separator; Step S6: the screen undersize is subjected to secondary cleaning by the flat plate magnetic separator to obtain flat plate concentrate slurry and flat plate tailings slurry, and the flat plate tailings are introduced into the cleaning operation of step S3; Step S7: the flat plate concentrate slurry is introduced into an inclined plate thickener for thickening to obtain inclined plate underflow and inclined plate overflow, and the inclined plate overflow is connected with the total tailings; Step S8: the inclined plate underflow is introduced into a disc filter for filtration to obtain fine particle grade titanium middlings product. The high gradient vertical ring strong magnetic machine constitutes a one-roughing and one-cleaning desliming process, the thickener is connected with the cleaning vertical ring strong magnetic machine and the stacked high-frequency vibration fine screen, the flat plate magnetic separator is sequentially connected with the stacked high-frequency vibration fine screen and the inclined plate thickener, and the disc filter is connected with the inclined plate thickener.

2. The method of recovering fine-grained titanium middlings according to claim 1, characterized in that, The concentration of the slurry in step S1 is calculated by the following formula and controlled at 15%-35%: ×100%； wherein, is the ore slurry concentration, is the dry mass of the tailings sample in kg, is the mass of water added in kg, the water addition is corrected during the conditioning process by real-time measurement of the ore slurry density to ensure a concentration deviation of ≤ ± 1%.

3. The process for recovering fine-grained titanium middlings according to claim 1, characterized in that, The separation magnetic field strength of the high gradient vertical ring strong magnetic roughing operation in step S2 is determined by the following optimization formula as 1-1.3T: wherein, is the roughing magnetic field strength, is the proportion of -200 mesh particles in the tailings sample, the medium box spacing of the vertical ring high-intensity magnetic machine is fixed at 2 mm, and the pulp passing speed is controlled at 0.8-1.2 m / s.

4. The method of recovering fine grained titanium middlings of claim 1, wherein, The separation magnetic field strength and medium box spacing of the high gradient vertical ring strong magnetic cleaning operation in step S3 satisfy the following correlation algorithm: wherein, is the intensity of the magnetic field for the cleaning, having a value ranging from 0.7 to 1.0 T, is the titanium grade of the cleaning concentrate, is the distance between the medium boxes, in mm, and is fixed at 1 mm, the residence time of the slurry in the cleaning operation being 1.5-2 times the residence time in the roughing operation.

5. The process for recovering fine grained titanium middlings according to claim 1, characterized in that, The concentration of the thickener underflow in step S4 is adjusted by the following control formula as 30-35%: ； wherein, is the thickener underflow concentration, is the thickener feed concentration, is the residence time of the ore slurry in the thickener, in min, is the thickening efficiency coefficient, having a value of 0.9-1.05, the thickener using intermediate feed, the overflow rate being controlled at 0.3-0.5 m3 / h.

6. The process for recovering fine grained titanium middlings according to claim 1, characterized in that, The screening efficiency of the stacked high-frequency vibration fine screen in step S5 satisfies the following calculation formula, and the screening efficiency is ≥80%: ； wherein, is the screening efficiency (%), is the mass of particles with a particle size > 0.074 mm in the undersize material (kg), is the mass of particles with a particle size > 0.074 mm in the feed material (kg); the screen mesh size is 0.074 mm, the equipment screening area is 8.75 m2, the vibration frequency is 1500 r / min, a polyurethane screen mesh resistant to blockage and wear is used, and the single-layer stacked screen throughput is < 5 t / h.

7. The method of recovering fine grained titanium middlings of claim 1, wherein, The ilmenite recovery rate of the flat plate magnetic separator in step S6 is calculated by the following model, and the recovery rate is ≥75%: wherein, is ilmenite recovery (%), is the feed grade of the plate magnetic separator (% TiO2), is the plate concentrate grade (% TiO2), is the plate tailings grade (% TiO2); the plate magnetic separator feed concentration is 30-40%, the belt surface magnetic field is 7000 GS, and a waterfall and concentrate discharge water are provided as auxiliary, with a water flow speed control of 0.2-0.3 m / s.

8. The method of recovering fine grained titanium middlings of claim 1, wherein, The underflow concentration of the inclined plate thickener in step S7 is controlled by the following optimization algorithm as 40-60%: wherein, is the inclined plate underflow concentration (%), is the ilmenite density (g / cm³), is the volume of solid particles in the flat plate concentrate slurry (m³), is the particle packing coefficient (value 0.6-0.7), is the density of water (g / cm³), is the volume of water in the flat plate concentrate slurry (m³), the inclination angle of the inclined plate thickener being 60-65°.

9. The process for recovering fine grained titanium middlings according to claim 1, characterized in that, The product moisture of the disc filter in step S8 is controlled by the following formula as ≤11%: Wherein, is the product moisture, is the feed processing capacity, is the filtration area, fixed at 5 m2, is the filtration pressure, control range 0.3-0.5 MPa, the fine particle grade titanium middling product after filtration has a titanium grade of 35%-40% and a yield of 1.4-2.8%.

10. The method of recovering fine grained titanium middlings of claim 8, wherein, The overflow of the thickener is connected with the underflow outlet of the high-frequency vibration fine screen, the concentrate outlet of the flat plate magnetic separator is connected with the feed inlet of the inclined plate thickener, the tailings outlet of the flat plate magnetic separator is connected with the feed inlet of the high-gradient vertical ring strong magnetic separation, and the underflow of the inclined plate thickener is connected with the feed inlet of the disc filter. When the underflow concentration of the inclined plate calculated in step S7 is lower than 40%, part of the underflow of the inclined plate is returned to the feed inlet of the inclined plate thickener for re-concentration through a reflux device. The reflux ratio is calculated according to the concentration deviation through the formula determined by calculation.

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