Beneficiation method for weathered ilmenite

Abstract

The invention discloses a beneficiation method for weathered ilmenite, and belongs to the technical field of beneficiation. According to the method, efficient recovery of the weathered ilmenite is achieved through the combined process of stage iron separation, strong magnetic pre-enrichment, multi-stage spiral chute separation, strong magnetic concentration and suspended vibration conical surface separation, and the separation indexes that the concentrate grade is 46% or above and the recovery rate is 70-78% are obtained. According to the suspended vibration conical surface concentrating machine, fine separation of titanium-containing middlings can be achieved, and compared with a conventional spiral chute and a conventional shaking table, the recovery rate of ilmenite concentrate can be increased by 5-10%, and the concentrate grade is increased by 3% or above. The method can avoid the over-grinding phenomenon, saves the cost, improves the recovery efficiency, and has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to a method for dressing weathered ilmenite. Background Art

[0002] Titanium is a rare metal resource. Titanium and its alloys are widely used in medical devices, coatings, aerospace, catalysis and military industries due to their excellent physical and chemical properties. China's titanium resource reserves rank first in the world, but 95% are found in primary vanadium-titanium magnetite, which is mainly distributed in Panzhihua and Chengde areas; followed by ilmenite sand ore, which is mainly distributed in Yunnan, Hainan and Guangdong and Guangxi, and the mining sites are relatively scattered. According to the degree of weathering, the titanium ore resources of titanium sand ore can be divided into weathered titanium ore, semi-weathered titanium ore and primary titanium ore. The three types of ores are distributed in layers (bands) from shallow to deep. Weathered ilmenite has the characteristics of high weathering degree, high mud content and loose structure. Titanium is mainly found in ilmenite and titanomagnetite. The gangue minerals are mainly clay minerals, and their content is usually more than 70%.

[0003] At present, the efficient separation of weathered ilmenite has always been a difficult problem in the field of ilmenite processing. Since most of the titanium magnets and ilmenite particles are tightly wrapped by clay minerals, and the embedded particle size of iron-containing and titanium minerals is uneven, the key to the separation of such ores is to economically and effectively achieve the monomer dissociation of the target minerals and develop a separation process that matches the characteristics of the ore. Over-grinding is very likely to occur during the grinding process of such ores, and the fine-grained ilmenite produced is mixed with ore mud and is difficult to recover. The existing physical separation is mainly based on strong magnetic separation pre-enrichment-conventional gravity separation, and only titanium concentrates with a titanium dioxide content of 40-45% and a recovery rate of 40-50% are obtained, resulting in serious waste of resources. On the other hand, due to the presence of a large amount of ore mud, flotation and efficient recovery of weathered ilmenite also face many challenges.

[0004] There have been relevant reports on the study of weathered ilmenite. Invention patent CN118218120 A discloses "a fully weathered ilmenite ultrasonic coupling separation process", which uses ultrasonic coupling mechanical stirring to reduce grinding costs, reduce fine particle output, and improve recovery. However, this process uses a method of pre-classification of strong magnetic concentrate-shaking table re-selection-middling return, which has the disadvantages of relatively complex process, large shaking table footprint, and easy accumulation of sludge and affecting the separation effect due to the return of middlings. Therefore, the existing process needs to be improved, and the research and development of weathered ilmenite beneficiation methods has great practical significance for the efficient development and utilization of such ores. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a beneficiation method for weathered ilmenite. According to the principle of stage grinding and stage sorting, the present invention realizes efficient recovery of weathered ilmenite through the combined sorting of "stage iron selection + strong magnetic pre-enrichment + multi-stage spiral chute sorting + strong magnetic concentration + suspended vibration cone sorting".

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The invention provides a beneficiation method for weathered ilmenite, which adopts stage grinding and stage weak magnetic separation to obtain iron concentrate and titanium-containing iron middlings; the weak magnetic tailings are subjected to strong magnetic rough separation to obtain strong magnetic concentrate and strong magnetic tailings; the strong magnetic concentrate is subjected to three spiral chute separations to obtain a spiral chute product, and the spiral chute product includes spiral chute rough concentrate, spiral chute middlings and spiral chute tailings; the spiral chute rough concentrate is subjected to graded closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and strong magnetic titanium middlings; the spiral chute middlings are ground and combined with the titanium-containing iron middlings and the strong magnetic titanium middlings for secondary suspension vibration cone concentrator separation to obtain titanium concentrate, thereby realizing efficient recovery of weathered ilmenite.

[0008] Furthermore, the method for beneficiating weathered ilmenite comprises the following steps:

[0009] (1) grinding the raw ilmenite ore and then performing wet weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings;

[0010] (2) grinding and wet weak magnetic separation of the weak magnetic coarse concentrate to obtain iron concentrate and titanium-containing iron middlings;

[0011] (3) subjecting the weak magnetic tailings to strong magnetic roughing to obtain strong magnetic concentrate and strong magnetic tailings;

[0012] (4) performing a first spiral chute separation on the strong magnetic concentrate to obtain spiral chute I rough concentrate, spiral chute I middlings and spiral chute I tailings;

[0013] (5) subjecting the spiral chute I coarse concentrate obtained in step (4) to a second spiral chute sorting to obtain spiral chute II coarse concentrate, spiral chute II middlings and spiral chute II tailings;

[0014] (6) subjecting the spiral chute II rough concentrate obtained in step (5) to a third spiral chute sorting to obtain spiral chute III rough concentrate, spiral chute III middlings and spiral chute III tailings;

[0015] (7) subjecting the spiral III coarse concentrate obtained in step (6) to classified closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and titanium middlings;

[0016] (8) grinding the spiral ore obtained in steps (4) to (6) (i.e., spiral ore I, spiral ore II, and spiral ore III), and subjecting the ore to rough separation with the titanium-containing iron ore obtained in step (2) and the titanium ore obtained in step (7) using a suspended vibration cone concentrator to obtain a coarse concentrate and tailings;

[0017] (9) The coarse concentrate obtained in step (8) is concentrated by a suspended vibration cone concentrator to obtain titanium concentrate and tailings.

[0018] The principle of the present invention is: based on the difference in mineral magnetism, firstly, strong magnetic iron minerals are recovered through stage weak magnetic separation, so as to achieve effective recovery of iron minerals and create good conditions for subsequent titanium selection process. Impurities containing non-titanium minerals such as kaolin are effectively removed through strong magnetic separation, and the concentration of ilmenite in subsequent steps is significantly improved. On this basis, based on the difference in particle size and density of minerals, a coherent processing chain of coarse concentrate is realized through multi-stage spiral chute sorting, so that titanium minerals can be effectively separated and concentrated at any stage. On this basis, the monomer dissociation degree of minerals is further improved by fine grinding, and the difference in mineral specific magnetic susceptibility is utilized to achieve effective enrichment of ilmenite through strong magnetic separation, thereby ensuring that the titanium concentrate finally obtained has a higher TiO2 content. For the medium ore rich in fine-grained ilmenite, according to the Baigno shear loosening theory and the principle of film dressing, the minerals of different densities are sequentially brought into the tailings tank, the medium ore tank and the concentrate tank through suspended vibration cone sorting, thereby achieving effective separation of fine-grained ilmenite and improving the recovery rate of total titanium.

[0019] Furthermore, in step (1), the particle size of the weathered ilmenite ore is 2 to 5 mm, and the grinding is performed until the particle size is -74 μm and the content of the particle size is 45 to 65 wt%; and / or

[0020] The magnetic field strength of the wet weak magnetic separation is 0.15-0.2T.

[0021] Furthermore, in step (2), the grinding is performed to a fineness of -38 μm with a particle size content of 75 to 85 wt%, and the appropriate grinding fineness can achieve an optimal balance between the grade and recovery rate of the titanium concentrate; and / or

[0022] The magnetic field strength of the wet weak magnetic separation is 0.1-0.15 T. The increase in magnetic field strength helps to improve the recovery rate, but will reduce the grade of titanium concentrate. Therefore, the appropriate magnetic field strength can achieve the best balance between the grade and recovery rate of titanium concentrate.

[0023] Furthermore, in step (3), the magnetic field strength of the strong magnetic roughing is 0.8 to 1.2 T. The magnetic field strength has a significant effect on the magnetism of the ore, thereby affecting its behavior in magnetic separation and the grade of the final concentrate. The appropriate magnetic field strength can achieve the best balance between the grade and recovery rate of the titanium concentrate.

[0024] Furthermore, in step (4) to step (6), when the spiral chute is separated, the feed concentration is 40-60wt%, the longitudinal inclination angle is 0.6°, and the horizontal inclination angle is 9°. The feed concentration has a significant effect on the separation effect of the spiral chute. If the feed concentration is too high, the viscosity of the slurry increases, the ore layer is not easy to loosen, resulting in the obstruction of the sedimentation of the ore particles, which seriously affects the stratification effect and the movement speed of the ore particles, thereby reducing the concentrate grade and recovery rate. If the feed concentration is too low, the processing volume per unit time is reduced, the mineral material layer becomes thinner, and it is impossible to stratify and zone, resulting in an increase in the slurry flow rate, and useful heavy minerals are discharged before they have time to stratify and settle, thereby increasing the tailings grade and reducing the separation efficiency. The intersection angle between the tangent of the spiral trough cross-section curve and the vertical axis is called the longitudinal inclination angle. The larger the longitudinal inclination angle, the faster the flow rate of the slurry and the greater the centrifugal force on the material. A suitable longitudinal inclination angle can make the slurry flow along the trough body, obtain good mineral processing indicators, and improve mineral processing efficiency. The horizontal inclination and the longitudinal inclination are complementary. The transverse inclination also affects the distribution of the pulp flow on the trough surface. The larger the transverse inclination, the greater the water flow depth. The appropriate transverse inclination helps to optimize the material sorting process, thereby affecting the grade of the final titanium concentrate.

[0025] Furthermore, in step (7), the classified closed-circuit grinding uses 0.05 mm as the classification limit, grinding +0.05 mm materials (i.e., ores with a particle size greater than 0.05 mm), and -0.05 mm materials (i.e., ores with a particle size less than 0.05 mm) as qualified products; and / or

[0026] The magnetic field strength of the strong magnetic selection is 0.6-0.8T.

[0027] Furthermore, in step (8), the grinding is grinding to a fineness of -74 μm with a particle size content of 85 to 95 wt%; and / or

[0028] The rotation frequency of the suspended vibration cone concentrator is 15-20 Hz, and the vibration frequency is 15-20 Hz.

[0029] Furthermore, in step (9), the rotation frequency of the suspended vibration cone concentrator is 10 to 15 Hz, and the vibration frequency is 15 to 20 Hz.

[0030] In the process of suspended vibration cone beneficiation, if the vibration frequency is too large, the vibration of the disc surface will be strengthened, the shear movement between the ore particles will be enhanced, and the looseness of the ore layer will also increase, resulting in a part of the titanium-containing minerals being washed away by the separation medium under the strong vibration of the disc surface, thereby reducing the recovery rate. The rotation speed of the separation surface directly determines the residence time of the separation material on the equipment, that is, it affects the time for the particle group to move on the separation surface, and then has a significant impact on its movement trajectory. Therefore, it plays a decisive role in the grade and recovery rate of the concentrate. When the rotation speed of the separation surface is too large, the material stays on the separation surface for too short a time, and the particle group has no time to loosen, stratify or stratify incompletely, resulting in the minerals not being removed in time and being directly brought to the concentrate tank under the action of gravity and washing water, thereby reducing the grade of the concentrate. When the rotation speed is too small, the material stays on the separation surface for too long, and the heavy mineral particles that have been sorted enter the tailings tank under the action of the separation surface vibration, their own gravity and washing water, resulting in a decrease in the recovery rate of the concentrate.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] (1) The present invention proposes a stage grinding and stage separation process, which not only reduces the grinding cost and obtains high-quality iron ore concentrate, but also reduces the impact on subsequent titanium selection.

[0033] (2) The process of "stage iron selection + strong magnetic pre-enrichment + multi-stage spiral chute separation + strong magnetic concentration + suspended vibration cone separation" of the present invention can effectively recover ilmenite, reduce energy consumption and save costs.

[0034] (3) The present invention uses a suspended vibration cone concentrator to concentrate titanium-containing middlings for fine separation. Compared with conventional gravity separation, the recovery rate of ilmenite concentrate can be increased by 5 to 10 percentage points, and the concentrate grade can be increased by more than 3 percentage points. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 The present invention provides a flow chart of the beneficiation process of weathered ilmenite. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0041] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0042] The ore dressing process flow chart of weathered ilmenite provided by the present invention is as follows: Figure 1 shown.

[0043] The present invention adopts the combined process of "stage iron selection + strong magnetic pre-enrichment + multi-stage spiral chute sorting + strong magnetic concentration + suspended vibration cone sorting" to achieve efficient recovery of weathered ilmenite, and obtains sorting indicators of concentrate grade of more than 46% and recovery rate of 70-78%. The suspended vibration cone concentrator in the present invention can realize the fine sorting of titanium-containing middlings. Compared with conventional spiral chutes and shaking tables, it can increase the recovery rate of ilmenite concentrate by 5-10 percentage points and the concentrate grade by more than 3 percentage points. The present invention can avoid over-grinding, save costs, improve recovery efficiency, and has broad application prospects.

[0044] The magnetic system of a wet magnetic separator is usually made of high-quality ferrite material or a composite with rare earth magnets. The working principle of a wet magnetic separator is to use the magnetic difference of minerals to separate them in the magnetic field of the magnetic separator. When mineral particles with different magnetic properties pass through the magnetic field of the magnetic separator, the mineral particles with stronger magnetic properties and the mineral particles with weaker magnetic properties are subjected to different magnetic forces, resulting in different movement trajectories, thereby achieving the separation of different minerals. The magnetic field strength of wet weak magnetic separation is relatively low, and the magnetic field strength of wet strong magnetic separation is relatively high.

[0045] "Feed concentration" refers to the content of solid mineral particles in the slurry fed into a certain operation or equipment during the mineral processing process.

[0046] The angle between the tangent of the spiral groove cross-section curve and the vertical axis is called the longitudinal inclination angle, and the horizontal inclination angle is complementary to the longitudinal inclination angle.

[0047] The "rotation frequency" of the suspended vibration cone concentrator refers to the number of revolutions of the conical surface per unit time, usually expressed in Hertz (Hz). The rotation frequency is one of the important parameters that affect the beneficiation effect. It determines the residence time of mineral particles on the sorting disc and the magnitude of the centrifugal force they are subjected to. The "vibration frequency" refers to the vibration frequency of the sorting disc, which is one of the core process parameters of the suspended vibration cone concentrator. The magnitude of the vibration frequency determines the movement state of the mineral particles on the equipment. It affects the movement speed of the mineral particles on the sorting disc and the looseness between the light and heavy minerals in the bed. In the suspended vibration cone concentrator, the rotation frequency and the vibration frequency work together to affect the stratification and sorting effect of the mineral particles. When the rotation frequency is high, the movement speed of the mineral particles on the sorting disc is accelerated, which may increase the risk of lighter minerals being mistakenly selected into the concentrate, thereby affecting the grade of the concentrate. Conversely, when the rotation frequency is low, the movement speed of the mineral particles on the sorting disc slows down, which helps the sedimentation and stratification of heavier minerals, but may reduce the processing volume and recovery rate.

[0048] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in the field and are not the focus of the present invention, such as the specific method of wet magnetic separation.

[0049] The technical solution of the present invention is further illustrated by the following embodiments.

[0050] Example 1

[0051] Taking a weathered ilmenite ore in Yunnan as an ore sample, the TiO2 content in the ore is 5.25wt%, the TFe (total iron in the ore) content is 12.57wt%, and the 2-5mm fragments in the ore sample account for 85.3wt%. The ore is a placer ore mainly composed of ilmenite and titanomagnetite, and the associated gangue minerals are mainly montmorillonite, plagioclase, potassium feldspar and quartz.

[0052] The beneficiation method of weathered ilmenite is as follows:

[0053] (1) grinding the weathered ilmenite ore to a particle size of -74 μm with a content of 45 wt%, and performing wet weak magnetic separation (called weak magnetic separation because the magnetic field strength is relatively low at this time) at a magnetic field strength of 0.18 T to obtain a weak magnetic coarse concentrate and a weak magnetic tailings;

[0054] (2) grinding the weak magnetic coarse concentrate to a particle size of -38 μm with a content of 75 wt%, and performing wet weak magnetic separation at a magnetic field strength of 0.15 T to obtain an iron concentrate and titanium-containing iron middlings;

[0055] (3) The weak magnetic tailings are subjected to strong magnetic roughing under a magnetic field strength of 1.0 T (the magnetic field strength is relatively high at this time, so it is called strong magnetic separation) to obtain strong magnetic concentrate and strong magnetic tailings (direct tailings);

[0056] (4) The strong magnetic concentrate is subjected to a spiral chute separation at a feed concentration of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute I rough concentrate, spiral chute I middlings, and spiral chute I tailings (directly discharged);

[0057] (5) The spiral chute I rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute II rough concentrate, spiral chute II middlings, and spiral chute II tailings (directly discharged);

[0058] (6) The spiral chute II rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 40%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute III rough concentrate, spiral chute III middlings, and spiral chute III tailings (directly discharged);

[0059] (7) The spiral III coarse concentrate is classified, the +0.05 mm material is ground and returned, and the -0.05 mm material is used as a strong magnetic separation material and is subjected to strong magnetic separation at a magnetic field strength of 0.6°T to obtain titanium concentrate and titanium middlings;

[0060] (8) Grinding the spiral ore obtained in steps (4) to (6) to a particle size content of -74 μm accounting for 85 wt%, and combining it with the titanium-containing iron ore obtained by weak magnetic separation and the titanium ore obtained by strong magnetic separation, and performing rough separation using a suspended vibration cone concentrator at a rotation frequency of 15 Hz and a vibration frequency of 15 Hz to obtain a coarse concentrate and tailings (directly discharged);

[0061] (9) The coarse concentrate obtained by suspended vibration cone separation is concentrated by a suspended vibration cone concentrator at a rotation frequency of 10 Hz and a vibration frequency of 15 Hz to obtain titanium concentrate and tailings (directly discharged).

[0062] Test results: The iron concentrate obtained in this embodiment has a grade of 62.45% and an iron recovery rate of 30.35%; the titanium concentrate TiO2 grade obtained by strong magnetic concentration is 47.66%, and the titanium recovery rate is 42.45%; the titanium concentrate TiO2 grade obtained by suspended cone concentrator is 42.15%, and the titanium recovery rate is 22.18%; the comprehensive titanium concentrate TiO2 grade is 45.61%, and the titanium recovery rate is 64.63%.

[0063] Example 2

[0064] Taking a weathered ilmenite in Yunnan as the ore sample, the TiO2 content in the original ore is 8.35wt%, the TFe content is 15.43wt%, and the particle size of 2-5mm fragments in the ore sample accounts for 75.6wt%. The ore is a placer ore mainly composed of ilmenite and titanomagnetite, and the associated gangue minerals are mainly montmorillonite, plagioclase, potassium feldspar, pyroxene and quartz.

[0065] The beneficiation method of weathered ilmenite is as follows:

[0066] (1) grinding the weathered ilmenite ore to a particle size of -74 μm with a content of 50 wt%, and performing wet weak magnetic separation at a magnetic field strength of 0.20 T to obtain a weak magnetic coarse concentrate and a weak magnetic tailings;

[0067] (2) grinding the weak magnetic coarse concentrate to a particle size of -38 μm with a content of 80 wt%, and performing wet weak magnetic separation at a magnetic field strength of 0.12 T to obtain an iron concentrate and titanium-containing iron middlings;

[0068] (3) subjecting the weak magnetic tailings to strong magnetic roughing under a magnetic field strength of 1.2 T to obtain strong magnetic concentrate and strong magnetic tailings (direct tailings discharge);

[0069] (4) The strong magnetic concentrate is subjected to a spiral chute separation at a feed concentration of 50wt%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute I rough concentrate, spiral chute I middlings, and spiral chute I tailings (directly discharged);

[0070] (5) The spiral chute I rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 50wt%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute II rough concentrate, spiral chute II middlings, and spiral chute II tailings (directly discharged);

[0071] (6) The spiral chute II rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 50%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute III rough concentrate, spiral chute III middlings, and spiral chute III tailings (directly discharged);

[0072] (7) The spiral III coarse concentrate is classified, the +0.05 mm material is ground and returned, and the -0.05 mm material is used as a strong magnetic separation material and is subjected to strong magnetic separation at a magnetic field strength of 0.7 T to obtain titanium concentrate and titanium middlings;

[0073] (8) grinding the spiral ore obtained in steps (4) to (6) to a particle size content of -74 μm accounting for 95 wt%, and combining it with the titanium-containing iron ore obtained by weak magnetic separation and the titanium ore obtained by strong magnetic separation, and performing rough separation by a suspended vibration cone concentrator at a rotation frequency of 18 Hz and a vibration frequency of 18 Hz to obtain a coarse concentrate and tailings (directly discharged);

[0074] (9) The coarse concentrate obtained by suspended vibration cone separation is concentrated by a suspended vibration cone concentrator at a rotation frequency of 14 Hz and a vibration frequency of 18 Hz to obtain titanium concentrate and tailings (directly discharged).

[0075] Test results: The iron concentrate obtained in this embodiment has a grade of 62.13% and an iron recovery rate of 35.15%; the titanium concentrate TiO2 grade obtained by strong magnetic concentration is 47.63%, and the titanium recovery rate is 48.51%; the titanium concentrate TiO2 grade obtained by suspended cone concentrator is 43.15%, and the titanium recovery rate is 19.44%; the comprehensive titanium concentrate TiO2 grade is 46.26%, and the titanium recovery rate is 67.95%.

[0076] Example 3

[0077] Taking a weathered ilmenite in Yunnan as the ore sample, the TiO2 content in the original ore is 10.15wt%, the TFe content is 17.85wt%, the particle size of 2-5mm fragments in the ore sample accounts for 72.5wt%, and the associated gangue minerals are mainly kaolin, plagioclase, potassium feldspar, pyroxene and olivine.

[0078] The beneficiation method of weathered ilmenite is as follows:

[0079] (1) grinding the weathered ilmenite ore to a particle size of -74 μm with a content of 65 wt%, and performing wet weak magnetic separation at a magnetic field strength of 0.18 T to obtain a weak magnetic coarse concentrate and a weak magnetic tailings;

[0080] (2) grinding the weak magnetic coarse concentrate to a particle size of -38 μm with a content of 85 wt%, and performing wet weak magnetic separation at a magnetic field strength of 0.1 T to obtain an iron concentrate and titanium-containing iron middlings;

[0081] (3) subjecting the weak magnetic tailings to strong magnetic roughing under a magnetic field strength of 1.2 T to obtain strong magnetic concentrate and strong magnetic tailings (direct tailings discharge);

[0082] (4) The strong magnetic concentrate is subjected to a spiral chute separation at a feed concentration of 60%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute I rough concentrate, spiral chute I middlings, and spiral chute I tailings (directly discharged);

[0083] (5) The spiral chute I rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 60%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute II rough concentrate, spiral chute II middlings, and spiral chute II tailings (directly discharged);

[0084] (6) The spiral chute II rough concentrate is subjected to secondary spiral chute separation at a feed concentration of 60%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain spiral chute III rough concentrate, spiral chute III middlings, and spiral chute III tailings (directly discharged);

[0085] (7) The spiral III coarse concentrate is classified, the +0.05 mm material is ground and returned, and the -0.05 mm material is used as a strong magnetic separation material and is subjected to strong magnetic separation at a magnetic field strength of 0.5 T to obtain titanium concentrate and titanium middlings;

[0086] (8) Grinding the spiral ore obtained in steps (4) to (6) to a particle size content of -74 μm accounting for 90 wt%, and combining it with the weakly magnetically selected titanium-containing iron ore and the strongly magnetically selected titanium ore, and performing rough separation with a suspended vibration cone concentrator at a rotation frequency of 20 Hz and a vibration frequency of 20 Hz to obtain a coarse concentrate and tailings (directly discharged);

[0087] (9) The coarse concentrate obtained by suspended vibration cone separation is concentrated by a suspended vibration cone concentrator at a rotation frequency of 15 Hz and a vibration frequency of 20 Hz to obtain titanium concentrate and tailings (directly discharged).

[0088] Test results: The iron concentrate obtained in this embodiment has a grade of 61.55% and an iron recovery rate of 34.65%; the titanium concentrate TiO2 grade obtained by strong magnetic concentration is 46.16%, and the titanium recovery rate is 50.56%; the titanium concentrate TiO2 grade obtained by suspended cone concentrator is 42.75%, and the titanium recovery rate is 20.74%; the comprehensive titanium concentrate TiO2 grade is 45.42%, and the titanium recovery rate is 71.3%.

[0089] Comparative Example 1

[0090] The ore dressing method of this comparative example is the same as that of Example 1, except that a spiral chute is used to replace the suspended vibration cone concentrator for roughing and concentrating in steps (8) and (9). The specific method is as follows: steps (1) to (7) are the same as those in Example 1, and step (8): grinding the spiral chute middlings obtained in steps (4) to (6) to a particle size content of -74 μm accounting for 90 wt%, and combining them with the weakly magnetically selected titanium-containing iron middlings and the strongly magnetically selected titanium middlings, performing a first spiral chute separation at a feed concentration of 40 wt%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain a first spiral chute concentrate, a first spiral chute middlings, and a first spiral chute tailings, wherein the first spiral chute middlings and the first spiral chute tailings are directly discharged, performing a second spiral chute separation on the first spiral chute concentrate at a feed concentration of 40 wt%, a longitudinal inclination of 0.6°, and a horizontal inclination of 9° to obtain a second spiral chute concentrate (i.e., titanium concentrate), and the second spiral chute middlings and the second spiral chute tailings are directly discharged.

[0091] The titanium concentrate obtained by spiral chute has a TiO2 grade of 38.75% and a titanium recovery rate of 16.21%.

[0092] Comparative Example 2

[0093] The ore dressing method of this comparative example is the same as that of Example 1, except that a shaking table is used instead of the suspended vibration cone concentrator for roughing and concentrating in steps (8) and (9). The specific method is as follows: steps (1) to (7) are the same as those in Example 1, and step (8): grinding the spiral ore obtained in steps (4) to (6) to a particle size content of -74 μm accounting for 90 wt%, and combining it with the weakly magnetically selected ilmenite-containing ore and the strongly magnetically selected titanium ore, performing the first shaking table separation under the conditions of a feed concentration of 40 wt%, a stroke of 11 mm, and a stroke of 360 times / min to obtain a first shaking table concentrate, a first shaking table ore and a first shaking table tailings, wherein the first shaking table ore and the first shaking table tailings are directly discharged, and performing the second shaking table separation on the first shaking table concentrate under the conditions of a feed concentration of 40 wt%, a stroke of 11 mm, and a stroke of 360 times / min to obtain a second shaking table concentrate (i.e., a titanium concentrate), and the second shaking table ore and the second shaking table tailings are directly discharged.

[0094] The titanium concentrate obtained by spiral chute has a TiO2 grade of 39.05% and a titanium recovery rate of 12.31%.

[0095] Comparative Example 3

[0096] The ore dressing method of this comparative example is the same as that of Example 2, except that a spiral chute is used instead of a suspended vibration cone concentrator for roughing and concentrating. The specific method is the same as that of Comparative Example 1.

[0097] The titanium concentrate obtained by spiral chute has a TiO2 grade of 39.12% and a titanium recovery rate of 14.12%.

[0098] Comparative Example 4

[0099] The ore dressing method of this comparative example is the same as that of Example 2, except that a shaking table is used instead of a suspended vibration cone concentrator for roughing and concentrating. The specific method is the same as that of Comparative Example 2.

[0100] The titanium concentrate obtained by shaking table concentration has a TiO2 grade of 39.23% and a titanium recovery rate of 11.05%.

[0101] Comparative Example 5

[0102] The ore dressing method of this comparative example is the same as that of Example 3, except that a spiral chute is used instead of a suspended vibration cone concentrator for roughing and concentrating. The specific method is the same as that of Comparative Example 1.

[0103] The titanium concentrate obtained by spiral chute has a TiO2 grade of 38.68% and a titanium recovery rate of 14.48%.

[0104] Comparative Example 6

[0105] The ore dressing method of this comparative example is the same as that of Example 3, except that a shaking table is used instead of a suspended vibration cone concentrator for roughing and concentrating. The specific method is the same as that of Comparative Example 2.

[0106] The titanium concentrate obtained by shaking table concentration has a TiO2 grade of 39.13% and a titanium recovery rate of 10.84%.

[0107] From the above comparative test results, it can be seen that the suspended vibration cone concentrator in the present invention can realize the refined separation of titanium-containing middlings. Compared with conventional spiral chutes and shaking tables, it can increase the recovery rate of ilmenite concentrate by 5-10 percentage points and the concentrate grade by more than 3 percentage points.

[0108] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for beneficiating weathered ilmenite, characterized in that: The iron concentrate and titanium-containing iron middlings are obtained by stage grinding and stage weak magnetic separation; the weak magnetic tailings are subjected to strong magnetic rough separation to obtain strong magnetic concentrate and strong magnetic tailings; the strong magnetic concentrate is separated by three spiral chutes to obtain a spiral chute product, which includes a spiral chute rough concentrate, a spiral chute middlings and a spiral chute tailings; the spiral chute rough concentrate is subjected to graded closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and strong magnetic titanium middlings; the spiral chute middlings are ground and combined with the titanium-containing iron middlings and the strong magnetic titanium middlings for secondary suspension cone concentrator separation to obtain titanium concentrate.

2. The method for beneficiating weathered ilmenite according to claim 1, characterized in that: The following steps are involved: (1) grinding the raw ilmenite ore and then performing wet weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings; (2) grinding and wet weak magnetic separation of the weak magnetic coarse concentrate to obtain iron concentrate and titanium-containing iron middlings; (3) subjecting the weak magnetic tailings to strong magnetic roughing to obtain strong magnetic concentrate and strong magnetic tailings; (4) performing a first spiral chute separation on the strong magnetic concentrate to obtain spiral chute I rough concentrate, spiral chute I middlings and spiral chute I tailings; (5) subjecting the spiral chute I coarse concentrate obtained in step (4) to a second spiral chute sorting to obtain spiral chute II coarse concentrate, spiral chute II middlings and spiral chute II tailings; (6) subjecting the spiral chute II rough concentrate obtained in step (5) to a third spiral chute sorting to obtain spiral chute III rough concentrate, spiral chute III middlings and spiral chute III tailings; (7) subjecting the spiral III coarse concentrate obtained in step (6) to classified closed-circuit grinding and strong magnetic separation to obtain titanium concentrate and titanium middlings; (8) grinding the spiral ore I, spiral ore II and spiral ore III, and subjecting them to rough separation with the titanium-containing iron ore obtained in step (2) and the titanium ore obtained in step (7) using a suspended vibration cone concentrator to obtain a coarse concentrate and tailings; (9) The coarse concentrate obtained in step (8) is concentrated by a suspended vibration cone concentrator to obtain titanium concentrate and tailings.

3. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (1), the particle size of the weathered ilmenite ore is 2 to 5 mm, and the grinding is grinding to a particle size of -74 μm with a content of 45 to 65 wt%; and / or The magnetic field strength of the wet weak magnetic separation is 0.15-0.2T.

4. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (2), the grinding is grinding to a fineness of -38 μm with a particle size content of 75 to 85 wt%; and / or The magnetic field strength of the wet weak magnetic separation is 0.1-0.15T.

5. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (3), the magnetic field strength of the strong magnetic roughing is 0.8-1.2T.

6. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In steps (4) to (6), during the spiral chute separation, the feed concentration is 40-60wt%, the longitudinal inclination angle is 0.6°, and the horizontal inclination angle is 9°.

7. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (7), the classification closed-circuit grinding uses 0.05 mm as the classification limit, grinding the +0.05 mm material and treating the -0.05 mm material as the qualified product; and / or The magnetic field strength of the strong magnetic selection is 0.6-0.8T.

8. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (8), the grinding is grinding to a fineness of -74 μm with a particle size content of 85 to 95 wt %; and / or The rotation frequency of the suspended vibration cone concentrator is 15-20 Hz, and the vibration frequency is 15-20 Hz.

9. The method for beneficiating weathered ilmenite according to claim 2, characterized in that: In step (9), the rotation frequency of the suspended vibration cone concentrator is 10 to 15 Hz, and the vibration frequency is 15 to 20 Hz.

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