Enrichment method of pyroxene peridotite type ilmenite

Abstract

The invention belongs to the technical field of metal beneficiation, and particularly discloses an enrichment method of pyroxene peridotite type ilmenite, which comprises the following steps: carrying out primary sloping plate concentration and deferrization magnetic separation after raw ore grinding and coarse separation to obtain secondary iron ore concentrate, and carrying out strong magnetic roughing, non-equidistant spiral reselection, cyclone classification, fine screen classification and cyclone classification dehydration on tailings to obtain pyroxene peridotite type ilmenite. And the screened fine particles are subjected to second-stage deferrization magnetic separation to obtain secondary iron concentrate, tailings are subjected to second-stage strong magnetic roughing and desulfurization flotation to obtain sulfur concentrate, and the tailings are subjected to inclined plate concentration desliming, floating titanium roughing and floating titanium concentration to obtain titanium concentrate. By means of the method, the TiO2 grade, the S content and the TiO2 recovery rate in the titanium concentrate in the enriched product can be improved, the zero breakthrough of resource recycling industrialization is achieved, and a mature and reliable technical support is provided for efficient development and utilization of low-grade ilmenite and pyroxene peridotite type ilmenite resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal ore dressing, and particularly relates to a method for enriching picrite-type ilmenite. Background Art

[0002] The separation process of primary ilmenite generally adopts the principle process flow of strong magnetic separation - flotation for weak magnetic separation iron tailings. However, due to the extremely similar physical and chemical properties of picrite-type ilmenite and its associated gangue minerals such as olivine, it is difficult to effectively separate ilmenite and olivine using the existing process flow and equipment technology. Especially when picrite ilmenite is enriched by strong magnetic separation, the obtained crude ilmenite concentrate has a low grade, a high content of impurities such as picrite, and does not meet the requirements of flotation grade. Moreover, compared with the flotation crude ilmenite concentrate grade of pyroxene-type ilmenite reaching 18 - 20%, the flotation grade of picrite ilmenite can only reach about 12 - 15%. Currently, there are no ready-made reagents and technologies that can be used.

[0003] For example, in the production of a certain picrite-type ilmenite, the classification efficiency is low. On the one hand, due to the prominent equal settlement phenomenon during the cyclone classification process, large-particle lean intergrowth minerals or light gangue are likely to enter the overflow end, and the +0.154mm particle size fraction content in the overflow reaches 20.19%, and the phenomenon of coarse particle running is serious. On the other hand, the content of slime minerals such as olivine, chlorite, and iddingsite reaches more than 50%, and the -0.038mm particle size fraction content in the grinding product reaches nearly 30%. With the high content of slime minerals, while the pulp viscosity increases, the specific surface energy of slime minerals is large, which is easy to form a cover on the surface of coarse-grained minerals and is not easy to desorb into the screen underflow, reducing the screening classification efficiency of the high-frequency fine screen. The screening efficiency is only about 45%. At the same time, the concentration of the oversize part of the high-frequency vibrating fine screen is only 58.5%, which is quite different from the grinding concentration (70%) and is difficult to directly enter the ball mill, but is discharged into the discharge pump sump of the ball mill. Therefore, the coarse-particle lean intergrowth minerals are infinitely circulated in the grinding classification combination system composed of a classification cyclone, a high-frequency vibrating fine screen, and a ball mill, and the classification efficiency becomes lower and lower.

[0004] Secondly, during the flotation process of the crude ilmenite concentrate, the main gangue minerals, olivine, titanaugite, altered chlorite, and iddingsite, are all easily slime-forming minerals, with a total content reaching 65.41%. A large amount of slime is easily generated during the grinding process. The cover of the slime on the surface of ilmenite reduces the surface property difference between ilmenite and gangue minerals. The slime has a large specific surface area and is easy to adsorb the flotation reagents non-selectively, consuming the reagents and deteriorating the subsequent flotation. Precise classification and efficient desliming have become the key factors for the effective separation of this ilmenite.

[0005] Thirdly, it is difficult to efficiently float and separate picrite-type ilmenite mainly because: (1) The floatability of ilmenite itself is poor. Although titanium and iron ions coexist on the surface of ilmenite, their suitable pH values for reacting with conventional ilmenite collectors are different. Ti4+ acts as an active site in a strongly acidic medium (pH value of 2 - 3), while Fe 2+ acts in weakly acidic and weakly alkaline pulp. Under specific flotation pH conditions, Ti 4+ and Fe 2+ cannot simultaneously become flotation active sites, and the action efficiency of conventional reagents is low; (2) A large amount of gangue minerals such as titanaugite, iddingsite, chlorite, and hematite are associated with ilmenite. Metal active sites such as titanium, iron, calcium, and magnesium are exposed on the surface of these minerals, making their surface properties similar to those of ilmenite. At the same time, Ti 4+ and Fe 2 + and Ca 2+ and Mg 2+ and other metal ions are re-adsorbed and precipitated on the surface of ilmenite, resulting in further convergence of the surface properties of ilmenite and gangue minerals.

[0006] Therefore, developing a new enrichment method for peridotite-type ilmenite is an urgent problem to be solved in this field. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies and defects in the background technology, adopt new processes and reagents, and innovatively provide an enrichment method for peridotite-type ilmenite to solve the technical problem of recovering peridotite-type ilmenite.

[0008] To solve the above technical problem, the technical solution proposed by the present invention is: An enrichment method for peridotite-type ilmenite, comprising the following steps: (1) After grinding the original ore of peridotite-type ilmenite and removing coarse slag by screening, perform primary inclined plate thickening to obtain primary inclined plate coarse particles and primary inclined plate overflow; (2) The primary inclined plate coarse particles obtained in step (1) are subjected to coarse particle deironing magnetic separation to obtain secondary iron concentrate and coarse particle iron tailings; (3) The coarse particle iron tailings obtained in step (2) are subjected to primary strong magnetic rougher separation for coarse particles. The primary strong magnetic rougher concentrate obtained is subjected to inclined plate thickening and then non-equidistant spiral re-election to obtain re-election concentrate; (4) The re-election concentrate obtained in step (3) enters a hydrocyclone for classification. The fine particles obtained by hydrocyclone classification enter a coarse particle fine screen for classification to obtain coarse particles and fine particles of coarse particle fine screen classification; The coarse particles of coarse particle fine screen classification enter a hydrocyclone for classification and dehydration. The classified and dehydrated coarse particles and the coarse particles obtained by hydrocyclone classification are ground together to obtain fine grinding particles, which are returned to the hydrocyclone classification process together with the classified and dehydrated fine particles; (5) The fine particles from the coarse particle and fine sieve classification in step (4) enter the second-stage iron removal magnetic separation to obtain secondary iron concentrate and tailings of the second-stage iron removal magnetic separation; (6) The tailings of the second-stage iron removal magnetic separation obtained in step (5) are subjected to second-stage strong magnetic roughing to obtain second-stage strong magnetic roughing concentrate and second-stage strong magnetic roughing tailings. The second-stage strong magnetic roughing tailings are returned to the non-equidistant spiral gravity separation process. The second-stage strong magnetic roughing concentrate is subjected to desulfurization flotation after inclined plate thickening to obtain sulfur concentrate and tailings of desulfurization flotation; (7) The tailings of the desulfurization flotation obtained in step (6) enter a desliming tank for inclined plate thickening desliming. The deslimed concentrate is subjected to rough titanium flotation and selective titanium flotation to obtain titanium concentrate; (8) The overflow of the first-stage inclined plate obtained in step (1) undergoes second-stage inclined plate thickening and coarse slag removal through coarse separation to obtain second-stage inclined plate fine particles; (9) The second-stage inclined plate fine particles obtained in step (8) undergo fine particle iron removal magnetic separation to obtain secondary iron concentrate and tailings of fine particle iron separation; (10) The tailings of the fine particle iron separation obtained in step (9) undergo first-stage strong magnetic roughing for fine particles. The first-stage strong magnetic roughing concentrate for fine particles is subjected to inclined plate thickening and then enters fine particle and fine sieve classification. The fine particles from the fine particle and fine sieve classification enter the second-stage iron removal magnetic separation process together with the fine particles from the coarse particle and fine sieve classification in step (5). The coarse particles from the fine particle and fine sieve classification enter the non-equidistant spiral gravity separation process together with the first-stage strong magnetic roughing concentrate for coarse particles in step (3) after inclined plate thickening.

[0009] In the above enrichment method of peridotite-type ilmenite, further, in the peridotite-type ilmenite raw ore, by mass fraction, it contains the following components: titanomagnetite 6 - 10%, ilmenite 4 - 7%, martite limonite 2 - 4%, metal sulfide 0.5 - 1%, maghemite 0.1 - 0.3%, olivine 42 - 48%, titanaugite 14 - 17%, plagioclase 8 - 12%, iddingsite 3 - 6%, hornblende 3 - 6%, biotite 0.1 - 1%, and the rest is others.

[0010] Further, the particle size standard for coarse separation is +1 mm, the particle size of the coarse particles obtained by the first-stage inclined plate thickening is +0.1 mm, and the particle size of the fine particles obtained by the second-stage inclined plate thickening is +0.019 mm.

[0011] Further, in step (3), the non-equidistant spiral gravity separation includes spiral roughing and at least 2 times of spiral scavenging; the spiral roughing obtains spiral roughing concentrate and spiral roughing tailings; the spiral roughing tailings enter the first spiral scavenging. The concentrate of the first spiral scavenging is returned to the spiral roughing process, and the tailings of the first spiral scavenging enter the second spiral scavenging; the concentrate of the second spiral scavenging is returned to the previous-stage spiral scavenging process, and so on; The spiral rough concentrate is subjected to spiral cleaning to obtain spiral cleaning concentrate and spiral cleaning tailings. The spiral cleaning tailings are returned to the non-uniform spiral gravity separation process, and the spiral cleaning concentrate is the gravity separation concentrate.

[0012] Further, in step (4), the conditions for cyclone classification are as follows: a hydraulic cyclone group with a diameter of Φ150 - Φ250mm is used, the feed pressure is controlled at 0.1 - 0.3MPa, two-stage classification is adopted. In the first-stage classification, the material is roughly separated to remove large particles or heavy phases. The overflow of the first-stage classification enters the second-stage fine separation to obtain cyclone classified fine particles and cyclone classified coarse particles. The classification particle size is set at 0.074 - 0.15mm, and the underflow concentration is maintained at 50 - 65wt%. The conditions for fine screen classification are as follows: a high-frequency vibrating fine screen is used, the screen hole is 0.075 - 0.15mm, the screen surface inclination angle is 15 - 25°, and the vibration frequency is 2000 - 3000 times / min. The conditions for cyclone classification and dewatering are as follows: a dehydration cyclone with a diameter of Φ75 - 125mm is used, the operating pressure is 0.3 - 0.6MPa, and the overflow particle size is controlled to be < 0.038 - 0.045mm. In step (10), the conditions for fine particle fine screen classification are as follows: a laminated high-frequency fine screen is used, the screen hole is 0.045 - 0.075mm, the screen surface is configured with 1 - 2 layers of stainless steel screen mesh, the feeding concentration is 20 - 35wt%, the screening process is washed with high-pressure water at 0.2 - 0.4MPa, and the content of -0.045mm in the screen - under product is ≥ 90wt%.

[0013] Further, in step (6), the inclined plate thickening conditions for desulfurization flotation are as follows: a polyethylene inclined plate group with a density of 0.941 - 0.965 g / cm³ is used, the inclined plate inclination angle is 55 - 60°, the plate spacing is 40 - 60mm, the surface loading rate is controlled at 0.6 - 1.2 m³ / (m²·h), the feeding concentration is 15 - 25wt%, and the fineness of the inclined plate thickening overflow is controlled so that the content of -0.038mm is < 20wt%. When the underflow concentration of the inclined plate thickening is increased to 40 - 50wt%, a polyacrylamide flocculant is added, and the dosage is 10 - 30g / t of ore. The pH value in the system is controlled at 6.5 - 7.5, and the inclined plate thickening process is sprayed with high-pressure water at 0.1 - 0.3MPa.

[0014] Further, in step (7), the inclined plate thickening and desliming is multi-stage desliming, where: First-stage desliming: a hydrocyclone desliming device with a diameter of Φ150mm - Φ300mm is used, the inlet pressure is 0.15 - 0.25MPa, and the +0.02mm coarse slime is removed. Second-stage desliming: an inclined plate thickener is used, the inclination angle is 60° - 70°, the residence time is 20 - 30min, and the 0.01 - 0.02mm fine slime is removed. Three-stage de-sludging: Inclined plate thickening and de-sludging is adopted, adding 50 - 80 g / t of modified starch inhibitor to remove ultra-fine slime with a particle size of less than -0.01 mm. The slime content with a particle size of less than -0.01 mm in the final de-sludged concentrate is less than 3 wt%, the total de-sludging recovery rate is ≥95%, and the moisture gradients of the de-sludging products in each stage are controlled as follows: the first stage is less than 25 wt%, the second stage is less than 30 wt%, and the third stage is less than 35 wt%.

[0015] Further, in step (7), the rough ilmenite flotation obtains rough ilmenite flotation concentrate and rough ilmenite flotation tailings; The rough ilmenite flotation tailings are subjected to rough ilmenite separation and at least two times of ilmenite scavenging flotation; the rough ilmenite separation obtains rough ilmenite separation concentrate and rough ilmenite separation tailings, and the ilmenite scavenging flotation concentrate obtained after the rough ilmenite separation tailings are subjected to ilmenite scavenging flotation is returned to the rough ilmenite flotation process; The rough ilmenite flotation concentrate is subjected to at least four times of ilmenite cleaning flotation to obtain ilmenite concentrate and ilmenite cleaning flotation tailings, and the ilmenite cleaning flotation tailings are returned to the rough ilmenite flotation process.

[0016] Further, in step (6), the mercapto collector used in the desulfurization flotation comprises the following raw materials in parts by mass: 3 - 5 parts of butyl xanthate and 1 part of sodium diethyldithiocarbamate. The dosage of the mercapto collector is 120 - 180 g / t of raw ore; the auxiliary collector used in the desulfurization flotation is diesel or kerosene, and the dosage is 10 - 20 g / t of raw ore for diesel and 5 - 15 g / t of raw ore for kerosene.

[0017] Further, in step (7), the ilmenite cleaning collector used in the ilmenite cleaning flotation comprises the following raw materials in parts by mass: 15 - 35 parts of linoleic acid hydroxamic acid crystal, 8 - 15 parts of calcium carboxylic acid, 10 - 20 parts of sodium hydroxide, and 15 - 30 parts of water; the preparation method of the ilmenite cleaning collector is as follows: Linoleic acid and hydroxamic acid are mixed and reacted at a molar ratio of 1:1.05 - 1.2, the reaction temperature is 60 - 80 °C, the reaction catalyst is H2SO4 or ionic liquid, and linoleic acid hydroxamic acid crystal is obtained by reaction; after mixing the raw materials, the reaction is carried out in an inert atmosphere, the reaction temperature is controlled at 40 - 60 °C, the reaction time is 2 - 5 h, the pH value of the reaction system is 8.5 - 10, and continuous stirring is carried out during the reaction, and the stirring speed is controlled at 360 - 600 revolutions per minute.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The enrichment method of olivine-type ilmenite provided by the present invention can improve the TiO2 grade, S content, and TiO2 recovery rate in the ilmenite concentrate of the enrichment product, achieving a zero breakthrough in the industrialization of the resource recovery and utilization, and providing a mature and reliable technical support for the efficient development and utilization of low-grade ilmenite and olivine-type ilmenite resources. Brief Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic diagram of the ionic bond, coordination bond and hydrogen bond between the collector functional group and the metal active site on the surface of ilmenite; Figure 2 It is the process flow chart of the embodiment of the present invention. Specific embodiments

[0021] The specific embodiment of the present invention is a method for enriching olivine-type ilmenite, as Figure 2 shown, including the following steps: S1. After grinding the original ore of olivine-type ilmenite and removing coarse slag by screening, perform primary inclined plate thickening to obtain primary inclined plate coarse grains and primary inclined plate overflow; the screening particle size standard for removing coarse slag is +1 mm, the particle size of the coarse grains obtained by the primary inclined plate thickening is +0.1 mm, and the particle size of the fine grains obtained by the secondary inclined plate thickening is +0.019 mm; S2. The primary inclined plate coarse grains are subjected to coarse-grained deironing magnetic separation to obtain secondary iron concentrate and coarse-grained iron tailings; The coarse-grained iron tailings are subjected to primary strong magnetic rougher separation for coarse grains to obtain primary strong magnetic rougher concentrate for coarse grains and primary strong magnetic rougher tailings for coarse grains; The primary strong magnetic rougher concentrate for coarse grains is subjected to inclined plate thickening and then non-equidistant spiral gravity separation. The non-equidistant spiral gravity separation includes spiral rougher separation and at least two times of spiral scavenging; the spiral rougher separation obtains spiral rougher concentrate and spiral rougher tailings; the spiral rougher tailings enter the first spiral scavenging, and the obtained first spiral scavenging concentrate returns to the spiral rougher separation process, and the obtained first spiral scavenging tailings enter the second spiral scavenging; the obtained second spiral scavenging concentrate returns to the previous-level spiral scavenging process, and so on; the spiral rougher concentrate is subjected to spiral cleaning to obtain spiral cleaning concentrate and spiral cleaning tailings, the spiral cleaning tailings return to the non-equidistant spiral gravity separation process, and the spiral cleaning concentrate is the gravity separation concentrate; The reselected concentrate enters a hydrocyclone for classification. A hydrocyclone group with a diameter of Φ150 - Φ250mm is used, and the feed pressure is controlled at 0.1 - 0.3MPa. Two-stage classification is adopted. In the first-stage classification, the material is roughly classified first to remove large particles or heavy phases. The overflow from the first-stage classification enters the second-stage fine classification to obtain hydrocyclone-classified fine particles and hydrocyclone-classified coarse particles. The classification particle size is set at 0.045 - 0.074mm, and the underflow concentration is maintained at 50 - 65wt%. The obtained hydrocyclone-classified fine particles enter a coarse-particle fine screen for classification. A high-frequency vibrating fine screen is used, with a screen hole of 0.075 - 0.15mm, a screen surface inclination of 15 - 25°, a vibration frequency of 2000 - 3000 times / min, and a screening efficiency > 85%. The coarse particles obtained from the coarse-particle fine screen classification enter a hydrocyclone for classification and dewatering. A dewatering hydrocyclone with a diameter of Φ75 - 125mm is used, and the operating pressure is 0.3 - 0.6MPa. The overflow particle size is controlled < 0.038 - 0.045mm, and the underflow yield > 75%. The obtained classified and dewatered coarse particles and the hydrocyclone-classified coarse particles are ground together. The ground fine particles and the classified and dewatered fine particles are returned to the hydrocyclone classification process. The fine particles obtained from the coarse-particle fine screen classification enter a second-stage iron removal magnetic separation to obtain a secondary iron concentrate and the tailings of the second-stage iron removal magnetic separation. The tailings of the second-stage iron removal magnetic separation are subjected to a second-stage strong magnetic roughing to obtain a second-stage strong magnetic roughing concentrate and the tailings of the second-stage strong magnetic roughing. The tailings of the second-stage strong magnetic roughing are returned to the non-equidistant spiral re-selection process. The second-stage strong magnetic roughing concentrate is concentrated by inclined plates and then subjected to desulfurization flotation. A high-density polyethylene inclined plate group is used, with an inclined plate angle of 55 - 60°, a plate spacing of 40 - 60mm, a surface loading rate controlled at 0.6 - 1.2 m³ / (m²·h), a feed concentration of 15 - 25wt%, and the fineness of the inclined plate concentrate overflow with a particle size of -0.038mm < 20%. When the underflow concentration of the inclined plate concentration is increased to 40 - 50wt%, a polyacrylamide flocculant is added, with a dosage of 10 - 30g / t ore, and the pH in the system is controlled at 6.5 - 7.5. The inclined plate concentration process uses a high-pressure water spray of 0.1 - 0.3MPa to obtain a sulfur concentrate and the tailings of the desulfurization flotation. The mercapto collector used in the desulfurization flotation includes the following raw materials in parts by mass: 3 - 5 parts of butyl xanthate and 1 part of sodium diethyldithiocarbamate. The dosage of the mercapto collector is 120 - 180g / t of raw ore. The auxiliary collector used in the desulfurization flotation is diesel or kerosene, with a dosage of 10 - 20g / t of raw ore for diesel and 5 - 15g / t of raw ore for kerosene. The tailings of the desulfurization flotation enter a desliming tank for inclined plate concentration and desliming. Multi-stage desliming is adopted, where: First-stage desliming: A hydrocyclone desliming device with a diameter of Φ150mm - Φ300mm is used, with an inlet pressure of 0.15 - 0.25MPa to remove coarse slime with a particle size of +0.02mm. Two-stage de-sludging: An inclined plate thickening tank is used, with an inclination angle of 60°-70°, a residence time of 20-30 min, and fine sludge with a particle size of 0.01-0.02 mm is removed. Three-stage de-sludging: Inclined plate thickening and de-sludging is adopted, and 50-80 g / t of modified starch inhibitor is added to remove ultra-fine sludge with a particle size of -0.01 mm; the content of -0.01 mm mud in the final de-sludged concentrate is <3%, the total de-sludging recovery rate is ≥95%, and the moisture gradients of the de-sludging products in each stage are controlled as follows: the first stage <25%, the second stage <30%, and the third stage <35%; the de-sludged concentrate obtained is subjected to rough ilmenite flotation to obtain rough ilmenite flotation concentrate and rough ilmenite flotation tailings. The rough ilmenite flotation tailings are subjected to rough ilmenite separation and at least two times of ilmenite scavenging; the rough ilmenite separation obtains rough ilmenite separation concentrate and rough ilmenite separation tailings, and the rough ilmenite separation tailings are subjected to the first ilmenite scavenging. The first ilmenite scavenging concentrate obtained is returned to the rough ilmenite flotation process, and the first ilmenite scavenging tailings obtained enter the second ilmenite scavenging; the second ilmenite scavenging concentrate obtained is returned to the previous-level ilmenite scavenging process, and so on. The rough ilmenite flotation concentrate is subjected to at least four times of ilmenite cleaning. The ilmenite cleaning tailings are subjected to the first ilmenite cleaning. The first ilmenite cleaning tailings obtained are returned to the rough ilmenite flotation process, and the first ilmenite cleaning concentrate obtained enters the second ilmenite cleaning; the second ilmenite cleaning concentrate obtained is returned to the previous-level ilmenite cleaning process, and the second ilmenite cleaning concentrate obtained enters the next-level ilmenite cleaning process, and so on, until ilmenite concentrate is obtained. The ilmenite cleaning collector used in the ilmenite cleaning includes the following raw materials in parts by mass: 15-35 parts of linoleic acid hydroxamic acid crystals, 8-15 parts of calcium carboxylate, 10-20 parts of sodium hydroxide, and 15-30 parts of water. The preparation method of the ilmenite collector is as follows: Linoleic acid and hydroxamic acid are mixed and reacted according to a molar ratio of linoleic acid∶hydroxylamine = 1:1.05-1.2. The reaction temperature is 60-80 °C, and the reaction catalyst is H2SO4 or ionic liquid. Linoleic acid hydroxamic acid crystals are obtained by reaction; the raw materials are mixed and reacted in an inert atmosphere; the reaction temperature is controlled at 40-60 °C, the reaction time is 2-5 h; continuous stirring is carried out during the reaction, and the stirring speed is controlled at 360-600 revolutions per minute; the pH value of the reaction system should be controlled at 8.5-10. The reaction vessel is preferably a stainless steel reaction kettle because it has good corrosion resistance. During the reaction, excessive contact with impurities such as oxygen and carbon dioxide in the air should be avoided.

[0022] S3. After the overflow of the first-stage inclined plate passes through secondary inclined plate thickening and coarse slag removal, secondary inclined plate fine particles are obtained. The secondary inclined plate fine particles are subjected to fine particle de-ironing magnetic separation to obtain secondary iron concentrate and fine particle iron separation tailings. The fine particle iron separation tailings are subjected to fine particle first-stage strong magnetic roughing to obtain fine particle first-stage strong magnetic roughing concentrate and fine particle first-stage strong magnetic roughing tailings. The fine-grained first-stage strong magnetic roughing concentrate enters the fine-grained fine screen classification after inclined plate thickening. A laminated high-frequency fine screen is used, with a screen hole of 0.045 - 0.075 mm, and 1 - 2 layers of stainless steel screen meshes are configured on the screen surface. The feeding concentration is 20 - 35 wt%. During the screening process, high-pressure water flushing at 0.2 - 0.4 MPa is adopted. The content of particles -0.045 mm in the undersize product is ≥90%. The fine particles obtained from the fine-grained fine screen classification enter the second-stage iron removal magnetic separation process together with the fine particles from the coarse-grained fine screen classification. The coarse particles obtained from the fine-grained fine screen classification enter the non-equidistant spiral gravity separation process together with the coarse-grained first-stage strong magnetic roughing concentrate after inclined plate thickening.

[0023] The technical principle of the present invention mainly includes the following aspects: In the first aspect, the present invention innovatively uses a hydrocyclone to classify and dehydrate the oversize products of the high-frequency vibrating fine screen, forming a three-stage combined classification of hydrocyclone classification - high-frequency fine screen classification - hydrocyclone classification and dehydration. Thus, on the one hand, through the high-frequency fine screen, it ensures that the coarse particles in the first-stage hydrocyclone classification are returned to the mill for fine grinding, achieving the goal of no coarse particle leakage, improving the overall classification efficiency, and at the same time making the hydrocyclone underflow concentration reach 76.8%, which can be directly returned to the mill without affecting the grinding concentration (the classification effect analysis is shown in Table 1); on the other hand, the overflow product of the hydrocyclone classification and dehydration directly enters the subsequent separation, reducing the over-grinding phenomenon caused by the fine-grained ilmenite entering the mill, and at the same time reducing the grinding energy consumption and medium loss.

[0024] Table 1 Comparison of effects of different classification methods / %

[0025] In the second aspect, the present invention adopts the stepped desliming technology. By using inclined plate thickening for desliming, solid particles settle on the inclined plate under their own gravity and then slide to the bottom, reducing the sedimentation distance of particles in water, promoting the sedimentation of mineral particles, increasing the sedimentation rate, and the light and fine-grained argillaceous minerals rise along the inclined plate to become the overflow. Due to the interference of liquid resistance, the amount of fine-grained argillaceous mineral particles in the overflow is less. Therefore, the amount of argillaceous minerals removed in each inclined plate overflow thickening process is small, and multi-stage desliming is required. At the same time, due to the large variety of minerals and significant differences in their specific gravities, some particles settle naturally and some rise with the water flow during the sedimentation process, interfering with each other. Classifying the argillaceous gangue minerals by specific gravity and gradually removing them step by step can reduce the mutual interference and improve the inclined plate thickening desliming effect. The present invention has developed a stepped desliming technology for classifying gangue by specific gravity, ultimately increasing the flotation concentrate grade by 0.93 percentage points and the recovery rate by 5.12 percentage points, and significantly reducing the reagent consumption (see Table 2).

[0026] Table 2 Comparison of stepped desliming effects / %

[0027] Thirdly, the present invention has developed a titanium ore collector (anionic collector) based on the coupling and synergy of hydrogen bonds and chemical bonds (ionic bonds / coordination bonds), and has developed a technology for the coordinated regulation and synchronous adsorption and flotation of Fe and Ti active sites on the surface of ilmenite. This titanium ore collector has three characteristics: (1) An appropriate number of carboxyl functional groups are introduced. This functional group can form ionic bonds with the Fe active sites on the surface of ilmenite and coordination bonds with the Ti active sites (as shown in Figure 1 ), realizing the coordinated regulation and synchronous adsorption of the collector on the Fe and Ti active sites on the surface of ilmenite, enhancing the efficiency of the collector acting on ilmenite, and ensuring the recovery rate of ilmenite; (2) The introduced hydroxyl functional groups are prone to form hydrogen bond adsorption with the hydroxylated Ti and Fe active sites on the surface of ilmenite (as shown in Figure 1 ). Although the hydrogen bond adsorption has a weak force, it has good selectivity; (3) It has strong acid resistance and can be used under low pH conditions. When the acidity of the pulp is high, H + can not only wash away the slime covering the surface of ilmenite and activate ilmenite, but also dissolve Ca, Mg, and Fe on the mineral surface into ions and enter the solution, reducing the number of active sites for competitive adsorption of the collector on the surface of gangue minerals, and enhancing the selectivity of the collector. The coupling and synergy of hydrogen bonds and chemical bonding enable the collector to synchronously adsorb on the Fe and Ti active sites on the surface of ilmenite, ensuring both the collecting ability of the reagent and selectivity, solving the flotation problem of extremely lean olivine-type ilmenite, and obtaining qualified titanium concentrate with a high recovery rate.

[0028] The results of the flotation comparison test of the above-mentioned titanium ore collector and conventional collectors for extremely lean olivine-type ilmenite are shown in Table 3. It can be seen that when the titanium concentrate obtained by the titanium ore collector of the present invention has a high TiO2 grade, the recovery rate is increased by 2 - 4 percentage points, significantly improving the recovery rate of extremely lean olivine-type ilmenite.

[0029] Table 3 Comparison of flotation test results of titanium ore collectors / %

[0030] To facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings of the specification and preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0031] Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0032] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0033] The original ilmenite ore of the ulvospinel type in the following examples contains the following components by mass fraction: titanomagnetite 8.6%, ilmenite 5.8%, martite limonite 2.5%, metal sulfide 0.6%, maghemite 0.1%, olivine 45.68%, titanaugite 15.61%, plagioclase 11.4%, iddingsite 4.12%, hornblende 4.01%, biotite 0.58%, and the rest is others.

[0034] Example 1: A method for enriching ilmenite ore of the ulvospinel type, comprising the following steps: (1) Raw ore treatment: The raw ilmenite ore of the ulvospinel type from a certain mining area in Panxi (TiO2 4.15wt%, S 0.34wt%) is crushed to -12mm and ground in a ball mill to -0.074mm accounting for 65%. (2) Primary inclined plate thickening: After removing the +1mm coarse slag by rough separation, thickening is carried out using an inclined plate group with an inclination angle of 55° to obtain coarse particles (+0.1mm) and overflow. (3) Coarse particle magnetic separation: The coarse particles are removed of secondary iron concentrate by weak magnetic separation (magnetic field intensity 0.3T), and the tailings enter the first-stage strong magnetic rough separation (1.2T).

[0035] (4) Non-equidistant spiral gravity separation: After the strong magnetic concentrate is thickened by an inclined plate, non-equidistant spiral chutes (pitch-diameter ratio of 0.6 - 0.8) are used for gravity separation to obtain gravity separation concentrate. (5) Hydrocyclone classification and fine screening: The gravity separation concentrate is classified by a Φ200mm hydrocyclone (pressure 0.2MPa, classification particle size set to 0.1mm, underflow concentration maintained at 60wt%). The fine particles enter a high-frequency fine screen (screen hole 0.1mm, screen surface inclination 20°, vibration frequency 3000 times / min, screening efficiency > 85%). The coarse particles enter the hydrocyclone classification and dehydration (Φ100mm dewatering hydrocyclone, operating pressure 0.4MPa, overflow particle size controlled < 0.045mm, underflow yield > 75%). The classified and dehydrated coarse particles and the hydrocyclone classified coarse particles are returned to grinding together, and the ground fine particles and the classified and dehydrated fine particles are returned to the hydrocyclone classification process together. (6) Second-stage iron removal magnetic separation: The fine particles classified by the fine screen are subjected to second-stage iron removal magnetic separation (0.3T) to obtain secondary iron concentrate. The tailings undergo second-stage strong magnetic rough separation to obtain second-stage strong magnetic rough separation concentrate and second-stage strong magnetic rough separation tailings. The second-stage strong magnetic rough separation tailings are returned to the non-equidistant spiral gravity separation process. The second-stage strong magnetic rough separation concentrate enters desulfurization flotation after thickening by an inclined plate. (7) Desulfurization flotation: The desulfurization flotation uses a compound of butyl xanthate and sodium diethyldithiocarbamate in a mass ratio of 4:1 (150g / t) and diesel (15g / t), pH = 6.0, to obtain sulfur rough concentrate (S 35%) and desulfurization flotation tailings; The inclined plate thickening conditions for desulfurization flotation are as follows: a polyethylene inclined plate group with a density of 0.95 g / cm³ is used, the inclination angle of the inclined plate is 60°, the plate spacing is 50 mm, the surface loading rate is controlled at 0.8 m³ / (m²·h), the feed concentration is 20 wt%, and the fineness of the overflow from the inclined plate thickening is controlled such that the content of particles smaller than 0.038 mm is less than 20 wt%. When the concentration of the underflow from the inclined plate thickening is increased to 40 wt%, a polyacrylamide flocculant is added at a dosage of 20 g / t of ore, the pH value in the system is controlled at 6.5, and high-pressure water spraying at 0.2 MPa is used during the inclined plate thickening process. (8) Stepwise de-sludging: The tailings from desulfurization flotation enter the de-sludging tank for inclined plate thickening de-sludging, and are de-sludged in three stages during the separation process, where: First-stage de-sludging: A Φ300 mm hydrocyclone de-sludging device is used, with an inlet pressure of 0.2 MPa, to remove coarse slime larger than 0.02 mm. Second-stage de-sludging: An inclined plate thickener is used, with an inclination angle of 70° and a residence time of 25 min, to remove fine slime between 0.01 and 0.02 mm. Third-stage de-sludging: Inclined plate thickening de-sludging is used, and a modified starch inhibitor is added at 60 g / t to remove ultra-fine slime smaller than 0.01 mm. The content of slime smaller than 0.01 mm in the final de-sludging concentrate is less than 3%, the total de-sludging recovery rate is ≥95%, and the moisture gradients of the de-sludging products in each stage are controlled as follows: the first stage is less than 25%, the second stage is less than 30%, and the third stage is less than 35%. The content of slime smaller than 0.01 mm in the final de-sludging concentrate is less than 2.5%. (9) Rough and fine titanium flotation: The obtained de-sludging concentrate is subjected to rough titanium flotation to obtain rough titanium flotation concentrate and rough titanium flotation tailings. The rough titanium flotation tailings are subjected to rough titanium separation and two-stage titanium scavenging. The rough titanium separation yields rough titanium separation concentrate and rough titanium separation tailings. The rough titanium separation tailings are subjected to titanium scavenging, and the titanium scavenging concentrate obtained is returned to the rough titanium flotation process. Then, a titanium flotation collector (30 parts of hydroxamic acid crystal of linoleic acid, 12 parts of carboxylic acid of calcium, 20 parts of sodium hydroxide, and 30 parts of water) is used, with a pH value of 5.0, and titanium concentrate and fine titanium flotation tailings are obtained after four-stage fine flotation. The fine titanium flotation tailings are returned to the rough titanium flotation process. (10) The overflow from the first-stage inclined plate thickening obtained in step (2) is subjected to second-stage inclined plate thickening and coarse slag removal to remove coarse slag. The fine particles (+0.019 mm) obtained from the second-stage inclined plate are subjected to fine particle deironing magnetic separation to obtain secondary iron concentrate and fine particle iron tailings after separation. The fine particle iron tailings after separation are subjected to first-stage strong magnetic roughing for fine particles. The concentrate obtained from the first-stage strong magnetic roughing for fine particles enters the inclined plate thickening and then enters the fine particle fine screen classification (sieve aperture 0.1 mm, 2 layers of stainless steel screen meshes are configured on the screen surface, the feeding concentration is 30 wt%, the screening process is washed with high-pressure water of 0.3 MPa, and the content of -0.045 mm in the undersize product is ≥90 wt%). The fine particles obtained from the fine particle fine screen classification and the fine particles obtained from the coarse particle fine screen classification enter the second-stage deironing magnetic separation process together. The coarse particles obtained from the fine particle fine screen classification and the concentrate from the first-stage strong magnetic roughing for coarse particles enter the non-equidistant spiral gravity separation process after inclined plate thickening together.

[0036] In this embodiment, the enrichment method of the present invention is adopted to process the iron tailings after separation in a certain mining area in Panxi. When the average grade of TiO2 in the raw ore is 4.15% and the average grade of S is 0.34%, and the grade of the flotation feed is only 12-15%, a titanium concentrate with a TiO2 grade of 47.35%, an S content of 0.164%, and a TiO2 recovery rate reaching 21.82% can be obtained, realizing a zero breakthrough in the industrialization of the resource recovery and utilization. The technical indicators are advanced. It provides mature and reliable technical support for the efficient development and utilization of low-grade ilmenite and olivine pyroxene type ilmenite resources in the Panxi area. The economic benefits are significant and the social benefits are remarkable.

[0037] Example 2: An enrichment method for olivine pyroxene type ilmenite, comprising the following steps: (1) Raw ore treatment: Select the raw ore of olivine pyroxene type ilmenite in a certain mining area in Liaoning (TiO2 3.8%, S 0.3%) and crush it to -12 mm, and grind it to -0.074 mm accounting for 70% by a ball mill.

[0038] (2) First-stage inclined plate thickening: After removing +1 mm coarse slag by coarse separation, use an inclined plate group with an inclination angle of 58° for thickening to obtain coarse particles (+0.1 mm) and overflow.

[0039] (3) Coarse particle magnetic separation: The coarse particles are subjected to weak magnetic separation (magnetic field intensity 0.35 T) to remove secondary iron concentrate, and the tailings enter the first-stage strong magnetic roughing (1.3 T).

[0040] (4) Non-equidistant spiral gravity separation: After the strong magnetic concentrate is thickened by an inclined plate, use a non-equidistant spiral chute (pitch-diameter ratio is 0.7-0.9) for gravity separation to obtain gravity separation concentrate.

[0041] (5) Hydrocyclone classification and fine screening: The gravity separation concentrate is classified by a Φ220mm hydrocyclone (pressure 0.25MPa, classification particle size set at 0.1mm, underflow concentration maintained at 50wt%). The fine particles enter a high-frequency fine screen (screen aperture 0.12mm, screen surface inclination 20°, vibration frequency 2000 times / min, screening efficiency > 85%). The coarse particles enter the hydrocyclone for classification and dehydration (Φ100mm dehydration hydrocyclone, operating pressure 0.4MPa, overflow particle size controlled < 0.045mm, underflow yield > 75%). The classified and dehydrated coarse particles obtained are returned to grinding together with the hydrocyclone classified coarse particles. The fine grinding particles and the classified and dehydrated fine particles are returned to the hydrocyclone classification process together.

[0042] (6) Second-stage iron removal magnetic separation: The fine particles classified by the fine screen are subjected to second-stage iron removal magnetic separation (0.35T) to obtain secondary iron concentrate. The tailings are subjected to second-stage strong magnetic roughing to obtain second-stage strong magnetic roughing concentrate and second-stage strong magnetic roughing tailings. The second-stage strong magnetic roughing tailings are returned to the non-equidistant spiral gravity separation process. The second-stage strong magnetic roughing concentrate enters desulfurization flotation after inclined plate thickening.

[0043] (7) Desulfurization flotation: The desulfurization flotation uses a compound of butyl xanthate and sodium diethyldithiocarbamate in a mass ratio of 4:1 (180g / t) and diesel (20g / t), pH = 6.5, to obtain sulfur rough concentrate (S 36%) and desulfurization flotation tailings; The inclined plate thickening conditions for desulfurization flotation are as follows: A polyethylene inclined plate group with a density of 0.95g / cm³ is used, the inclined plate inclination is 55°, the plate spacing is 50mm, the surface loading rate is controlled at 0.8 m³ / (m²·h), the feed concentration is 25wt%, and the fineness of the inclined plate thickening overflow with a particle size of -0.038mm is controlled < 20wt%. When the underflow concentration of the inclined plate thickening is increased to 40wt%, a polyacrylamide flocculant is added, with a dosage of 30g / t of ore, and the pH in the system is controlled at 6.5. The inclined plate thickening process uses 0.15MPa high-pressure water spraying.

[0044] (8) Stepwise de-sludging: The desulfurization flotation tailings enter a de-sludging tank for inclined plate thickening and de-sludging, and are de-sludged in three stages during the separation process, where: First-stage de-sludging: A Φ300mm hydrocyclone de-sludger is used, with an inlet pressure of 0.25MPa, to remove coarse sludge with a particle size of +0.02mm; Second-stage de-sludging: An inclined plate thickener is used, with an inclination angle of 70° and a residence time of 20min, to remove fine sludge with a particle size of 0.01 - 0.02mm; Third-stage de-sludging: Inclined plate thickening and de-sludging are used, and a modified starch inhibitor of 70g / t is added to remove ultra-fine sludge with a particle size of -0.01mm. The mud content with a particle size of -0.01mm in the final de-sludged concentrate is < 3%, the total de-sludging recovery rate is ≥ 95%, and the moisture gradients of the de-sludging products in each stage are controlled as follows: the first stage < 25%, the second stage < 30%, and the third stage < 35%; The content of -0.01mm mud in the final de-sludged concentrate is < 2.8%.

[0045] (9)Rough and fine ilmenite flotation: The obtained de-sludged concentrate is subjected to rough ilmenite flotation to obtain rough ilmenite flotation concentrate and rough ilmenite flotation tailings. The rough ilmenite flotation tailings are subjected to rough ilmenite separation and two-stage ilmenite scavenging. The rough ilmenite separation yields rough ilmenite separation concentrate and rough ilmenite separation tailings. The rough ilmenite separation tailings are subjected to ilmenite scavenging, and the obtained ilmenite scavenging concentrate is returned to the rough ilmenite flotation process. Then, a titanium ore collector (25 parts of hydroxyoxime acid crystal of linoleic acid, 10 parts of calcein carboxylic acid, 20 parts of sodium hydroxide, and 30 parts of water) is used, with pH = 5.5, and ilmenite concentrate and fine ilmenite flotation tailings are obtained through five-stage fine flotation. The fine ilmenite flotation tailings are returned to the rough ilmenite flotation process. (10)The overflow of the first-stage inclined plate thickening obtained in step (2) undergoes second-stage inclined plate thickening and removal of coarse slag to obtain fine particles (+0.019mm) of the second-stage inclined plate. After fine particle deironing magnetic separation, secondary iron concentrate and fine particle iron separation tailings are obtained. The fine particle iron separation tailings undergo rough separation by strong magnetic separation in the first stage of fine particles. The obtained rough concentrate of the first stage of strong magnetic separation of fine particles enters inclined plate thickening and then enters fine particle fine screening classification (screen hole 0.1mm, 2 layers of stainless steel screen meshes are configured on the screen surface, the feeding concentration is 30wt%, high-pressure water with 0.2 - MPa is used for flushing during the screening process, and the content of -0.045mm in the undersize product is ≥ 90wt%). The fine particles obtained from the fine particle fine screening classification and the fine particles obtained from the coarse particle fine screening classification enter the second-stage deironing magnetic separation process together. The coarse particles obtained from the fine particle fine screening classification and the rough concentrate of the first stage of strong magnetic separation of coarse particles enter inclined plate thickening and then enter the non-equidistant spiral gravity separation process together.

[0046] In this example, the enrichment method of the present invention is adopted to process the ore selected from a certain mining area in Liaoning. When the average grade of TiO2 in the original ore is 3.8% and the average grade of S is 0.3%, under the condition that the grade of the flotation feed is about 12 - 14%, ilmenite concentrate with a TiO2 grade of 46.8%, an S content of 0.18%, and a TiO2 recovery rate of 19.5% is obtained. It provides an effective reference for the development and utilization of similar low-grade ilmenite and olivine pyroxene type ilmenite resources, promotes the development of related resource recovery and utilization industries, and has certain economic and social benefits.

[0047] Example 3: An enrichment method for olivine pyroxene type ilmenite, comprising the following steps: (1)Original ore treatment: Select the original ore of a certain olivine pyroxene type ilmenite in Yunnan region (TiO2 4.3%, S 0.32%) and crush it to -12mm, and grind it in a ball mill to -0.074mm accounting for 60%.

[0048] (2)First-stage inclined plate thickening: After removing +1mm coarse slag by coarse separation, thickening is carried out using an inclined plate group with an inclination angle of 56° to obtain coarse particles (+0.1mm) and overflow.

[0049] (3) Coarse-grained magnetic separation: The coarse grains are subjected to weak magnetic separation (magnetic field intensity 0.28 T) to remove secondary iron concentrate, and the tailings enter the first-stage strong magnetic roughing (1.1 T).

[0050] (4) Non-equidistant spiral gravity separation: After the strong magnetic concentrate is concentrated by inclined plates, non-equidistant spiral launders (pitch-diameter ratio of 0.6 - 0.7) are used for gravity separation to obtain gravity separation concentrate.

[0051] (5) Hydrocyclone classification and fine screening: The gravity separation concentrate is classified by a Φ180 mm hydrocyclone (pressure 0.18 MPa, classification particle size set at 0.1 mm, underflow concentration maintained at 50 wt%). The fine particles enter a high-frequency fine screen (screen aperture 0.09 mm), and the coarse particles enter the hydrocyclone for classification and dewatering (Φ100 mm dewatering hydrocyclone, operating pressure 0.4 MPa, overflow particle size controlled < 0.045 mm, underflow yield > 75%). The classified and dewatered coarse particles and the hydrocyclone-classified coarse particles are returned to grinding together, and the ground fine particles and the classified and dewatered fine particles are returned to the hydrocyclone classification process together.

[0052] (6) Second-stage iron removal magnetic separation: The fine particles classified by the fine screen are subjected to second-stage iron removal magnetic separation (0.3 T) to obtain secondary iron concentrate. The tailings undergo second-stage strong magnetic roughing to obtain second-stage strong magnetic roughing concentrate and second-stage strong magnetic roughing tailings. The second-stage strong magnetic roughing tailings are returned to the non-equidistant spiral gravity separation process, and the second-stage strong magnetic roughing concentrate enters desulfurization flotation after being concentrated by inclined plates.

[0053] (7) Desulfurization flotation: The desulfurization flotation uses a compound of butyl xanthate and sodium diethyldithiocarbamate in a mass ratio of 4:1 (160 g / t) and diesel (18 g / t), pH = 6.2, to obtain sulfur rough concentrate (S 35.5%) and desulfurization flotation tailings; The inclined plate concentration conditions for desulfurization flotation are as follows: Polyethylene inclined plate groups with a density of 0.95 g / cm³ are used, the inclined plate angle is 55°, the plate spacing is 40 mm, the surface loading rate is controlled at 0.9 m³ / (m²·h), the feed concentration is 15 wt%, and the fineness of the inclined plate concentration overflow with a particle size of -0.038 mm is controlled < 20 wt%. When the underflow concentration of the inclined plate concentration is increased to 50 wt%, a polyacrylamide flocculant is added, with a dosage of 30 g / t of ore, and the pH in the system is controlled at 7.5. The inclined plate concentration process uses high-pressure water spraying at 0.3 MPa.

[0054] (8) Stepwise de-sliming: The desulfurization flotation tailings enter a de-sliming tank for inclined plate concentration and de-sliming, and are de-slimed in three stages during the separation process, where: First-stage de-sliming: A Φ300 mm hydrocyclone de-slimer is used, with an inlet pressure of 0.2 MPa, to remove coarse slime with a particle size of +0.02 mm; Second-stage de-sliming: An inclined plate thickener is used, with an inclination angle of 70° and a residence time of 25 min, to remove fine slime with a particle size of 0.01 - 0.02 mm; Three-stage de-sludging: Inclined plate thickening and de-sludging is adopted, adding 60 g / t of modified starch inhibitor to remove ultra-fine slime of -0.01 mm; the slime content of -0.01 mm in the final de-sludged concentrate is < 3%, and the total de-sludging recovery rate is ≥ 95%. The moisture gradients of the de-sludging products in each stage are controlled as follows: the first stage < 25%, the second stage < 30%, and the third stage < 35%. The slime content of -0.01 mm in the final de-sludged concentrate is < 2.6%.

[0055] (9)Rough and fine titanium flotation: The de-sludged concentrate obtained is subjected to rough titanium flotation to obtain rough titanium flotation concentrate and rough titanium flotation tailings. The rough titanium flotation tailings are subjected to rough titanium separation and two-stage titanium scavenging. The rough titanium separation obtains rough titanium separation concentrate and rough titanium separation tailings. The rough titanium separation tailings are scavenged to obtain titanium scavenging concentrate, which is returned to the rough titanium flotation process; then a titanium flotation collector (32 parts of hydroxyoxime acid crystal of linoleic acid, 13 parts of calcium carboxylate, 20 parts of sodium hydroxide, 30 parts of water) is used, with pH = 5.2. After four-stage fine flotation, titanium concentrate and fine titanium flotation tailings are obtained, and the fine titanium flotation tailings are returned to the rough titanium flotation process. (10)The overflow of the first-stage inclined plate thickening obtained in step (2) is subjected to secondary inclined plate thickening and removal of coarse slag to obtain secondary inclined plate fine particles (+0.019 mm). After fine particle de-ironing magnetic separation, secondary iron concentrate and fine particle iron separation tailings are obtained; the fine particle iron separation tailings are subjected to rough strong magnetic separation in the first stage of fine particles. The rough strong magnetic separation concentrate of the first stage of fine particles enters the fine particle fine screen classification after inclined plate thickening (screen hole 0.1 mm, 2 layers of stainless steel screen mesh are configured on the screen surface, the feeding concentration is 35 wt%, and the screening process is washed with 0.4 MPa high-pressure water. The content of -0.045 mm in the screen under product is ≥ 90 wt%). The fine particles obtained from the fine particle fine screen classification and the fine particles obtained from the coarse particle fine screen classification enter the secondary de-ironing magnetic separation process together. The coarse particles obtained from the fine particle fine screen classification and the rough strong magnetic separation concentrate of the first stage of coarse particles enter the non-equidistant spiral gravity separation process after inclined plate thickening.

[0056] In this embodiment, the enrichment method of the present invention is adopted to process the peridotite-type ilmenite raw ore. When the average grade of TiO2 in the raw ore is 4.3% and the average grade of S is 0.32%, the flotation feed grade is between 12 - 15%. A titanium concentrate with a TiO2 grade of 47.1%, an S content of 0.17%, and a TiO2 recovery rate of 20.5% is obtained. It further verifies the effectiveness of the method of the present invention, provides a technical basis for the recovery and utilization of peridotite-type ilmenite resources with different characteristics, has positive significance for promoting the development and utilization of low-grade ilmenite resources, and creates certain economic and social benefits.

[0057] Comparative Example 1: The peridotite-type ilmenite is enriched by the existing technology, including the following steps: (1)Raw ore treatment: Take the same peridotite-type ilmenite raw ore from a certain mining area in Panxi as in Example 1 (TiO2 4.15%, S 0.34%), crush it to -12 mm, and grind it in a ball mill to -0.074 mm accounting for 65%.

[0058] (2)Primary inclined plate thickening: After removing +1 mm coarse slag by rough separation, use ordinary thickening equipment (without using inclined plate thickening, relying only on natural sedimentation by gravity) for thickening to obtain coarse grains and overflow.

[0059] (3)Coarse grain magnetic separation: The coarse grains are removed of secondary iron concentrate by weak magnetic separation (magnetic field intensity 0.3 T), and the tailings enter the strong magnetic rough separation (1.2 T).

[0060] (4)Conventional spiral gravity separation: After the strong magnetic concentrate is simply thickened, use an ordinary equidistant spiral chute for gravity separation to obtain gravity separation concentrate.

[0061] (5)Single cyclone classification: The gravity separation concentrate is classified by a Φ200 mm cyclone (pressure 0.2 MPa). After classification, the products are not subjected to fine screen classification and directly enter the subsequent process.

[0062] (6)Secondary iron removal magnetic separation: The classified products are removed of iron by strong magnetic separation (0.3 T), and the tailings enter the desulfurization flotation.

[0063] (7)Desulfurization flotation: Use conventional flotation reagents (ordinary xanthate and foaming agent, without precise proportioning), control the pH (at 5 - 7) to obtain sulfur rough concentrate.

[0064] (8)Simple de-sludging: The titanium ore dressing raw material only undergoes one-stage simple hydrocyclone de-sludging. After de-sludging, the -0.01 mm clay content in the concentrate is about 5%.

[0065] (9)Fine titanium flotation: Use conventional titanium ore dressing collectors (without using the formula of the present invention), pH = 5.0, and obtain titanium concentrate after four times of fine flotation.

[0066] This comparative example uses a conventional method to treat the same raw ore. Under the conditions of an average TiO2 grade of 4.15% in the raw ore, an average S grade of 0.34%, and a flotation feed grade of 12 - 15%, the TiO2 grade of the obtained titanium concentrate is only 44.5%, the S content is 0.25%, and the TiO2 recovery rate is only 15%. Compared with the example, the titanium concentrate has a low grade, a high impurity content, and a low recovery rate, and it is impossible to achieve efficient resource recovery and utilization. It is far inferior to the example in terms of economic and social benefits, highlighting the advantages of the method of the present invention in treating peridotite-type ilmenite.

Claims

1. A method for enriching olivine-type ilmenite, characterized in that: The following steps are involved: (1) After grinding the olivine-type ilmenite ore and removing the coarse slag by separation, the primary inclined plate thickener is carried out to obtain the primary inclined plate coarse particles and the primary inclined plate overflow; (2) The coarse particles obtained from the primary inclined plate in step (1) are subjected to coarse particle de-ironization and magnetic separation to obtain secondary iron concentrate and coarse particle iron separation tailings; (3) The coarse iron ore tailings obtained in step (2) are subjected to coarse first-stage strong magnetic roughing, and the coarse first-stage strong magnetic roughing concentrate obtained is concentrated on an inclined plate and then subjected to non-equidistant spiral gravity separation to obtain a gravity separation concentrate; (4) The re-selected concentrate obtained in step (3) enters a cyclone for classification, and the obtained cyclone-classified fine particles enter a coarse-grained fine screen for classification, and obtains coarse particles classified by coarse-grained fine screen and coarse particles classified by coarse-grained fine screen; the coarse particles classified by coarse-grained fine screen enter a cyclone for classification and dehydration, and the obtained classified and dehydrated coarse particles are ground together with the cyclone-classified coarse particles, and the obtained ground fine particles are returned to the cyclone classification process together with the classified and dehydrated fine particles; (5) The coarse particles and fine particles classified by the fine screen in step (4) enter the second stage of de-ironization magnetic separation to obtain the secondary iron concentrate and the second stage of de-ironization magnetic separation tailings; (6) The second-stage de-ironization magnetic tailings obtained in step (5) are subjected to second-stage strong magnetic roughing to obtain second-stage strong magnetic roughing concentrate and second-stage strong magnetic roughing tailings, and the second-stage strong magnetic roughing tailings are returned to the non-equidistant spiral gravity separation process. The second-stage strong magnetic roughing concentrate is subjected to desulfurization flotation after being concentrated on an inclined plate to obtain a sulfur concentrate and a desulfurization flotation tailings; (7) The desulfurized flotation tailings obtained in step (6) enter the desludging tank for inclined plate concentration and desludging, and the desludging concentrate obtained is subjected to titanium flotation roughing and titanium flotation concentration to obtain titanium concentrate; (8) The overflow from the first inclined plate obtained in step (1) is concentrated and separated by a second inclined plate to remove coarse slag, thereby obtaining second inclined plate fine particles; (9) The secondary inclined plate fine particles obtained in step (8) are subjected to fine particle de-ironization magnetic separation to obtain secondary iron concentrate and fine particle iron separation tailings; (10) The fine iron-selected tailings obtained in step (9) are subjected to fine first-stage strong magnetic roughing, and the fine first-stage strong magnetic roughing concentrate obtained is concentrated on an inclined plate and then enters a fine screen for classification. The fine particles obtained from the fine screen classification are entered into a second-stage de-ironification magnetic separation process together with the coarse particles obtained from the fine screen classification in step (5). The coarse particles obtained from the fine screen classification are concentrated on an inclined plate together with the coarse first-stage strong magnetic roughing concentrate in step (3) and then enter a non-equidistant spiral gravity separation process.

2. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: The olivine-type ilmenite ore contains the following components by mass fraction: 6-10% titanomagnetite, 4-7% ilmenite, 2-4% pseudo-hematite and limonite, 0.5-1% metal sulfide, 0.1-0.3% magnetic hematite, 42-48% olivine, 14-17% titanopyroxene, 8-12% plagioclase, 3-6% eddingite, 3-6% hornblende, 0.1-1% biotite, and the rest are others.

3. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: The particle size standard of the coarse separation is +1mm, the coarse particle size obtained by the first-stage inclined plate concentration is +0.1mm, and the fine particle size obtained by the second-stage inclined plate concentration is +0.019mm.

4. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: In step (3), the non-equidistant spiral gravity separation includes spiral roughing and at least two spiral sweepings; the spiral roughing obtains spiral roughing concentrate and spiral roughing tailings; the spiral roughing tailings enter the spiral sweeping process, the spiral sweeping concentrate obtained is returned to the spiral roughing process, and the spiral sweeping tailings obtained enter the spiral sweeping process; the spiral sweeping concentrate obtained by the spiral sweeping process returns to the previous spiral sweeping process, and so on; The spiral roughing concentrate is subjected to spiral concentration to obtain a spiral concentration concentrate and a spiral concentration tailings. The spiral concentration tailings are returned to the non-equidistant spiral gravity separation process, and the spiral concentration concentrate is the gravity separation concentrate.

5. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: In step (4), the cyclone classification conditions are: using a Φ150-Φ250 mm hydrocyclone group, controlling the feed pressure at 0.1-0.3 MPa, setting the classification particle size at 0.074-0.15 mm, and maintaining the underflow concentration at 50-65 wt%; The conditions for fine screening classification are: using a high-frequency vibrating fine screen with a screen hole of 0.075-0.15 mm, a screen surface inclination of 15-25°, and a vibration frequency of 2000-3000 times / min; The conditions for the cyclone graded dehydration are: using a Φ75-125mm dehydration cyclone, an operating pressure of 0.3-0.6MPa, and an overflow particle size control of <0.038-0.045mm; In step (10), the conditions for fine particle screening and classification are: using a laminated high-frequency fine screen with a screen hole of 0.045-0.075 mm, 1-2 layers of stainless steel screens on the screen surface, a feed concentration of 20-35 wt%, and a screening process using 0.2-0.4 MPa high-pressure water flushing, and the content of the screened product -0.045 mm is ≥90 wt%.

6. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: In step (6), the inclined plate concentration conditions for desulfurization flotation are as follows: a polyethylene inclined plate group with a density of 0.941-0.965 g / cm³ is used, the inclined plate inclination angle is 55-60°, the plate spacing is 40-60 mm, the surface load rate is controlled to be 0.6-1.2 m³ / (m².h), the feed concentration is 15-25wt%, and the inclined plate concentration overflow fineness is controlled to be -0.038mm content <20wt%; when the inclined plate concentration underflow concentration is increased to 40-50wt%, polyacrylamide flocculant is added in an amount of 10-30g / t ore, the pH in the control system is controlled to be 6.5-7.5, and 0.1-0.3MPa high-pressure water spray is used in the inclined plate concentration process.

7. The enrichment method of olivine-type ilmenite according to claim 1, characterized in that: In step (7), the inclined plate thickening and desludging is a multi-stage desludging process, wherein: First stage desludging: using Φ150mm-Φ300mm cyclone desludging device, inlet pressure 0.15-0.25MPa, remove +0.02mm coarse mud; Second stage desludging: using inclined plate thickener, with an inclination angle of 60°-70°, residence time of 20-30min, to remove 0.01-0.02mm fine mud; Three-stage desliming: Use inclined plate concentration desliming, add 50-80g / t of modified starch inhibitor to remove -0.01mm ultrafine mud; the -0.01mm mud content in the final deslimed concentrate is less than 3wt%, the total desliming recovery rate is ≥95%, and the moisture gradient of each stage of desliming products is controlled to be <25wt% in the first stage, <30wt% in the second stage, and <35wt% in the third stage.

8. The method for enriching olivine-type ilmenite according to claim 1, characterized in that: In step (7), the titanium flotation roughing obtains titanium flotation roughing concentrate and titanium flotation roughing tailings; The titanium flotation roughing tailings are subjected to titanium flotation roughing and at least two titanium flotation scavenging processes; the titanium flotation roughing process obtains titanium flotation roughing concentrate and titanium flotation roughing tailings, and the titanium flotation scavenging concentrate obtained after the titanium flotation roughing tailings are subjected to titanium flotation scavenging is returned to the titanium flotation roughing process; The titanium flotation roughing concentrate is subjected to at least four titanium flotation concentrations to obtain titanium concentrate and titanium flotation concentration tailings, and the titanium flotation concentration tailings are returned to the titanium flotation roughing process.

9. The method for enriching olivine-type ilmenite according to claim 1, characterized in that: In step (6), the mercapto collector used in the desulfurization flotation comprises the following raw materials in parts by weight: 3-5 parts of butyl xanthate and 1 part of sodium diethyldithiocarbamate, and the amount of the mercapto collector is 120-180 g / t of raw ore; the auxiliary collector used in the desulfurization flotation is diesel or kerosene, and the amount is 10-20 g / t of raw ore for diesel and 5-15 g / t of raw ore for kerosene.

10. The method for enriching olivine-type ilmenite according to any one of claims 1 to 9, characterized in that: In step (7), the titanium-selective collector used in the floating titanium selection comprises the following raw materials in parts by weight: 15-35 parts of linoleic acid hydroxamic acid crystals, 8-15 parts of calcium carboxylic acid, 10-20 parts of sodium hydroxide, and 15-30 parts of water; the preparation method of the titanium-selective collector is as follows: linoleic acid: hydroxamic acid are mixed in a molar ratio of 1:1.05-1.2 for reaction, the reaction temperature is 60-80°C, the reaction catalyst is H2SO4 or an ionic liquid, and the reaction obtains linoleic acid hydroxamic acid crystals; the raw materials are mixed and reacted in an inert atmosphere, the reaction temperature is controlled at 40-60°C, the reaction time is 2-5h, the pH value of the reaction system is 8.5-10, and stirring is continued during the reaction, and the stirring speed is controlled at 360-600 rpm.

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