Dry reselection method for treating high-silicon bauxite

Abstract

The invention provides a dry reselection method for treating high-silicon bauxite, and belongs to the field of mineral processing. The method comprises the steps that raw ore is subjected to primary grading, and first coarse-fraction ore and first fine-fraction ore are obtained; the first coarse fraction ore is subjected to vibration feeding and photoelectric separation, and pre-selected concentrate and pre-selected tailings are obtained; the first fine-fraction ore and the pre-selected tailings are combined for crushing and secondary grading, and second coarse-fraction ore and second fine-fraction ore are obtained; the second coarse-fraction ore is subjected to wind separation, and coarse-fraction concentrate and coarse-fraction tailings are obtained; the second fine-fraction ore is subjected to electric separation, and fine-fraction concentrate and fine-fraction tailings are obtained; the coarse-fraction concentrate, the fine-fraction concentrate and the pretreated concentrate are combined into concentrate; and the coarse-fraction tailings and the fine-fraction tailings are combined into tailings. The technology of primary grading pretreatment, crushing secondary grading, coarse fraction wind power gravity separation and fine fraction electric separation is adopted, so that silicon minerals and aluminum minerals in the high-silicon bauxite are effectively separated, and the ore grade is improved.

Description

Technical Field

[0001] This application relates to the technical field of mineral processing, and particularly to a dry gravity separation method for treating high-silica bauxite ore. Background Art

[0002] The bauxite ore resources in China are 5.2 billion tons, with a reserve of 676 million tons, accounting for 2.2% globally. The domestic alumina output in 2024 was 85.522 million tons, accounting for more than 58% of the global output. High-quality bauxite ore resources are becoming increasingly depleted. With the gradual scarcity of high-quality bauxite ore resources, China's dependence on imported bauxite ore has increased sharply, and the external dependence in 2023 has reached as high as more than 68%. Domestic bauxite ore is characterized by high aluminum, high silicon, and low aluminum-silicon ratio. At the same time, with the rapid development of technology and increasingly stringent environmental protection requirements, the high-quality and efficient utilization of bauxite ore resources has become extremely urgent. Optimizing the cut-off grade of resources has become particularly crucial and urgent, which is an inevitable choice to meet the dual needs of economic development and environmental protection.

[0003] Domestic bauxite ore is mainly of the diaspore type, and medium- and low-grade ore resources account for more than 70%. Currently, the conventional flotation desilication technology applied industrially has problems such as large initial investment and high cost, complex process flow, poor ore applicability, high energy consumption for fine grinding and dissociation of ore, fine particle size of beneficiation tailings, high moisture content, and difficulty in stacking and disposal due to drug residues, resulting in high beneficiation difficulty. In the context of the continuous decline in the grade of domestic bauxite ore resources and resource tension, the conventional flotation desilication technology is no longer suitable due to the above problems, and it is urgent to iterate the beneficiation and impurity removal process of bauxite ore. Summary of the Invention

[0004] This application provides a dry gravity separation method for treating high-silica bauxite ore to solve the following technical problems: how to effectively separate silicon minerals and aluminum minerals in high-silica bauxite ore to improve the ore grade.

[0005] An embodiment of this application provides a dry gravity separation method for treating high-silica bauxite ore, and the method includes:

[0006] Performing primary classification on the raw ore to obtain first coarse-grained ore and first fine-grained ore;

[0007] Vibrating and feeding and performing optoelectronic separation on the first coarse-grained ore for pretreatment to obtain pre-concentrate and pre-tailings;

[0008] Combining the first fine-grained ore and the pre-tailings for crushing and secondary classification to obtain second coarse-grained ore and second fine-grained ore;

[0009] Performing air separation on the second coarse-grained ore to obtain coarse-grained concentrate and coarse-grained tailings;

[0010] Perform electric separation on the second fine-grained ore to obtain fine-grained concentrate and fine-grained tailings;

[0011] Combine the coarse-grained concentrate, the fine-grained concentrate, and the pretreated concentrate into concentrate; and

[0012] Combine the coarse-grained tailings and the fine-grained tailings into tailings.

[0013] Optionally, the raw ore satisfies the following conditions: Al 2 O 3 mass fraction ≥ 45.00%, SiO 2 mass fraction ≥ 20.00%, A / S ≤ 3, particle size ≤ 50 mm.

[0014] Optionally, the particle size of the first coarse-grained ore is -50 + 20 mm, and the particle size of the first fine-grained ore is -20 mm.

[0015] Optionally, the vibrating feeder uses a vibrating feeder machine, the vibration frequency of the vibrating feeder machine is 25 Hz, and the discharge end of the vibrating feeder machine is a conical discharge port.

[0016] Optionally, the optoelectronic separation uses an XRT optoelectronic separator, the optoelectronic separation adopts X-ray projection separation technology, and the light source intensity of the optoelectronic separation is 80 kV to 100 kV.

[0017] Optionally, in the optoelectronic separation technology, the separation threshold f is 10000 ± 200; where

[0018] When f ≥ 10000, preselected tailings are obtained by separation;

[0019] When f < 10000, preselected concentrate is obtained by separation.

[0020] Optionally, the particle size of the second coarse-grained ore is -3 + 0.15 mm, and the particle size of the second fine-grained material is -0.15 mm.

[0021] Optionally, the air separation uses an air jigger, and the air jigger satisfies the following conditions: air flow velocity is 2.0 m / s to 2.5 m / s, vibration frequency is 300 times / min to 400 times / min, amplitude is 5 mm to 8 mm, and bed layer thickness is 80 mm to 100 mm.

[0022] Optionally, the electric separation uses a drum-type electrostatic separator, and the number of times of electric separation ≥ 2 times.

[0023] Optionally, the drum-type electrostatic separator meets the following conditions: the motor polarity is a negative corona electrode, the voltage is 20 kV to 35 kV, the motor spacing is 60 mm to 80 mm, and the drum rotation speed is 90 rpm to 130 rpm.

[0024] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0025] The embodiments of the present application provide a dry gravity separation method for treating high-silica bauxite. The method includes: performing primary classification on the raw ore to obtain a first coarse-grained ore and a first fine-grained ore; performing vibrating feeding and optoelectronic separation on the first coarse-grained ore for pretreatment to obtain a pre-selected concentrate and a pre-selected tailing; combining the first fine-grained ore and the pre-selected tailing for crushing and secondary classification to obtain a second coarse-grained ore and a second fine-grained ore; performing air separation on the second coarse-grained ore to obtain a coarse-grained concentrate and a coarse-grained tailing; performing electric separation on the second fine-grained ore to obtain a fine-grained concentrate and a fine-grained tailing; combining the coarse-grained concentrate, the fine-grained concentrate, and the pre-treated concentrate into a concentrate; combining the coarse-grained tailing and the fine-grained tailing into a tailing. By adopting the process of "primary classification pretreatment - crushing secondary classification - coarse-grained air gravity separation - fine-grained electric separation", the low-grade high-silica bauxite can obtain an aluminum concentrate with a high alumina content, a relatively high aluminum-silicon ratio, and relatively few impurity contents after treatment. The process is simple and no chemical reagents are added throughout the process. The concentrate is suitable for the production of alumina by the Bayer process, and there are no reagents in the tailing and it is neutral and can be safely stacked or backfilled into the mine. Thus, the silicon minerals and aluminum minerals in the high-silica bauxite are effectively separated, and the ore grade is improved. Description of the Drawings

[0026] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a schematic flow chart of a dry gravity separation method for treating high-silica bauxite provided by the embodiments of the present application;

[0029] Figure 2 It is a schematic actual flow chart of a dry gravity separation method for treating high-silica bauxite provided by the embodiments of the present application. Detailed Embodiments

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0031] The various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0032] In addition, in the description of the specification of the present application, terms such as "including" and "comprising" mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. In this text, "at least one" means one or more, and "multiple" means two or more. "At least one kind", "at least one item (piece) below" or similar expressions refer to any combination of these items, including any combination of single item (piece) or plural items (pieces). For example, "at least one item (piece) among a, b, or c", or "at least one item (piece) among a, b, and c" can both represent: a, b, c, a-b (that is, a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple respectively. "Part representation methods" such as weight parts and mass parts represent the proportional relationship between each component. In the proportional relationships involved in this text, the parameters that need to be described by the ratio should be understood as the antecedents of the ratio formula in the order of description, and the ratio numbers should be understood as the consequents of the ratio formula. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one by one with the ratio numbers in the ratio formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0033] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present application can be obtained through market purchase or can be prepared by existing methods.

[0034] Figure 1 It is a schematic flow chart of a dry gravity separation method for treating high-silica bauxite provided for the embodiments of the present application.

[0035] As Figure 1 shown, the present application provides a dry gravity separation method for treating high-silica bauxite, and the method includes:

[0036] S1. Classify the raw ore once to obtain a first coarse-grained ore and a first fine-grained ore;

[0037] In some embodiments, the raw ore satisfies the following conditions: Al 2 O 3 mass fraction ≥ 45.00%, SiO 2 mass fraction ≥ 20.00%, A / S ≤ 3, particle size ≤ 50 mm.

[0038] In some embodiments, the particle size of the first coarse-grained ore is -50 + 20 mm, and the particle size of the first fine-grained ore is -20 mm.

[0039] The useful mineral in the raw ore is diaspore, and the gangue minerals are kaolinite, illite, pyrophyllite and quartz.

[0040] In some embodiments, the primary classification is carried out by dry screening and classification using a straight-line screen.

[0041] S2. Carry out vibrating feeding and optoelectronic separation on the first coarse-grained ore for pretreatment to obtain pre-concentrate and pre-tailings;

[0042] In some embodiments, a vibrating feeder is used for vibrating feeding. The vibration frequency of the vibrating feeder is 25 Hz, and the discharge end of the vibrating feeder is a conical discharge port.

[0043] The discharge end of the vibrating feeder is a conical discharge port to ensure that the ore can be laid flat on the optoelectronic separator one by one.

[0044] In some embodiments, an XRT optoelectronic separator is used for optoelectronic separation. The optoelectronic separation adopts X-ray projection separation technology, and the light source intensity of the optoelectronic separation is 80 kV to 100 kV.

[0045] In some embodiments, in the optoelectronic separation technology, the separation threshold f is 10,000 ± 200; where

[0046] When f ≥ 10,000, pre-tailings are obtained by separation;

[0047] When f < 10,000, pre-concentrate is obtained by separation.

[0048] Since there is a certain density difference between aluminum minerals and silicon minerals, when separating by X-ray penetration technology, the attenuation degrees of X-rays are different, so that aluminum minerals and silicon minerals are separated. In this embodiment, the light source intensity used by the XRT optoelectronic separator is 80 - 100 kV. This is mainly because ores with different particle sizes will affect the penetrability of X-rays. If the particle size of the ore is large and the light source intensity is insufficient to cause the ore to be penetrated by X-rays, the separation effect will be reduced; at the same time, the setting of the separation threshold f (gray value) will also affect the optoelectronic separation effect. Exemplarily, the light source intensity of the optoelectronic separation can be 80 kV, 85 kV, 90 kV, 95 kV, 100 kV, etc.

[0049] S3. Combine the first fine-grained ore and the pre-tailings for crushing and secondary classification to obtain a second coarse-grained ore and a second fine-grained ore;

[0050] In some embodiments, the equipment used for crushing is a high-pressure roller crusher, and the crushing particle size is 3 mm.

[0051] In some embodiments, the equipment used for the secondary classification is a combination of a straight-line screen and a high-frequency laminated vibrating screen.

[0052] In some embodiments, the particle size of the second coarse-grained ore is -3 + 0.15 mm, and the particle size of the second fine-grained material is -0.15 mm.

[0053] S4. Wind-separate the second coarse-grained ore to obtain coarse-grained concentrate and coarse-grained tailings;

[0054] In some embodiments, the wind separation uses a wind jigger, and the wind jigger meets the following conditions: the air flow velocity is 2.0 m / s to 2.5 m / s, the vibration frequency is 300 times / min to 400 times / min, the amplitude is 5 mm to 8 mm, and the bed layer thickness is 80 mm to 100 mm.

[0055] The air flow velocity is limited to 2.0 m / s to 2.5 m / s. The air flow velocity determines the suspension and stratification effects of the particles. If it is too high, both light and heavy minerals will be blown away. If it is too low, the particles cannot be effectively stratified, affecting the separation effect. The vibration frequency is limited to 300 times / min to 400 times / min, and the amplitude is 5 mm to 8 mm. The vibration frequency and amplitude control the jumping height of the particles and the looseness of the bed layer. For ores with different particle sizes, low frequency is suitable for coarse-grained separation, and high frequency is suitable for fine-grained separation. The bed layer thickness is limited to 80 mm to 100 mm. The bed layer thickness affects the separation time and stratification effect. If it is too thick, it is easy to cause incomplete stratification, affecting the separation effect. Exemplarily, the air flow velocity of the wind jigger can be 2.0 m / s, 2.1 m / s, 2.2 m / s, 2.3 m / s, 2.4 m / s, 2.5 m / s, etc., the vibration frequency can be 300 times / min, 320 times / min, 340 times / min, 360 times / min, 380 times / min, 400 times / min, etc., the amplitude can be 5 mm, 6 mm, 7 mm, 8 mm, etc., and the bed layer thickness can be 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, etc.

[0056] S5. Electrically separate the second fine-grained ore to obtain fine-grained concentrate and fine-grained tailings;

[0057] In some embodiments, the electric separation uses a drum-type electrostatic separator, and the number of times of the electric separation is ≥2 times.

[0058] In some embodiments, the drum-type electrostatic separator meets the following conditions: the motor polarity is a negative corona electrode, the voltage is 20 kV to 35 kV, the motor spacing is 60 mm to 80 mm, and the drum rotation speed is 90 rpm to 130 rpm.

[0059] The motor polarity of the drum-type electrostatic separator is a negative corona electrode, and the voltage is controlled at 20 - 35 kV. This is mainly because the conductivity of diaspore is better than that of silicon minerals, and medium to high voltage is required to enhance the polarization adsorption of non-conductive impurities and at the same time avoid excessive charging and detachment of aluminum minerals. Limiting the electrode spacing of the drum-type electrostatic separator to 60 - 80 mm can balance the electric field strength and discharge stability and strengthen the polarization effect on silicon minerals; limiting the drum rotation speed to 90 - 130 rpm can extend the separation time to ensure sufficient adsorption of silicon minerals and at the same time avoid aluminum minerals from being mixed into the tailings due to excessive centrifugal force. Exemplarily, the voltage can be 20 kV, 25 kV, 30 kV, 32 kV, 35 kV, etc., the motor spacing can be 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, etc., and the drum rotation speed can be 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, etc.

[0060] S6. Combine the coarse-grained concentrate, the fine-grained concentrate, and the pretreated concentrate into a concentrate; and

[0061] S7. Combine the coarse-grained tailings and the fine-grained tailings into tailings.

[0062] A dry gravity separation method for treating high-silica bauxite provided by an embodiment of the present application can effectively separate silicon minerals and aluminum minerals in bauxite, reduce production costs, improve the ore grade, and realize the efficient and high-value utilization of bauxite resources, having significant social and economic benefits.

[0063] In summary, a dry gravity separation method for treating high-silica bauxite provided by an embodiment of the present application has the following specific advantages:

[0064] (1) Environmental protection and energy saving of the dry separation process: The entire process adopts dry separation (such as linear screen classification, XRT optoelectronic separation, air jigs separation, etc.), avoiding the dependence on water in the traditional ore washing method, reducing wastewater discharge and environmental pollution. At the same time, the high-pressure roll crusher (crushing the particle size to 3 mm) combined with the classification and feeding strategy reduces the energy consumption in the grinding process, and the cost per ton of ore is reduced compared with the traditional flotation process. In addition, the conical discharge port design of the vibrating feeder ensures that the ore is laid flat, reducing the risk of dust generation during optoelectronic separation, meeting the requirements of green mines.

[0065] (2) Synergistic enhancement of multi-stage separation technology: The XRT optoelectronic separator (light source intensity 80 - 100 kV) accurately removes siliceous waste rocks (such as kaolinite and quartz) based on the density difference between aluminum and silicon minerals, improving the aluminum-silicon ratio of the pre-selected concentrate in the coarse particle size fraction. Meanwhile, for the fine particle size fraction, combined wind-electric separation is carried out. The air jig (airflow 2.0 - 2.5 m / s, vibration frequency 300 - 400 times / min) realizes density stratification of -3 + 0.15 mm particle size ore through the combined action of airflow and vibration, separating coarse particle size aluminum minerals from silicon minerals. In addition, the drum-type electrostatic separator (voltage 20 - 35 kV, drum rotation speed 90 - 130 rpm) utilizes the conductivity difference between diaspore and silicon minerals to enhance the polarization adsorption of fine particle size (-0.15 mm) silicon minerals, improving the purity of the concentrate.

[0066] (3) Fine-tuning of process parameters to improve separation efficiency: Set the separation threshold f = 10000 ± 200, and accurately identify aluminum and silicon minerals through the difference in X-ray attenuation degree, significantly reducing the subsequent processing load. Meanwhile, the negative corona electrode and medium-high voltage (20 - 35 kV) of the electrostatic separator parameters enhance the polarization of silicon minerals while avoiding excessive charging of aluminum minerals, improving the recovery rate of aluminum concentrate.

[0067] (4) Improvement of resource utilization rate and economic benefits: Primary classification of the raw ore (-50 + 20 mm coarse particle size fraction, -20 mm fine particle size fraction) reduces ineffective crushing. Combined with secondary classification (-3 + 0.15 mm, -0.15 mm), it realizes fine-grained separation of particle size, reducing energy consumption. The pre-selected tailings are crushed and incorporated into the secondary separation process to maximize the recovery of aluminum resources and reduce the tailings discharge. Meanwhile, dry separation eliminates the costs of flotation reagents and wet dewatering, and the comprehensive processing cost per ton of ore is lower than that of the traditional flotation method.

[0068] (5) Technical compatibility and industrialization potential: Equipment such as linear screens, XRT optoelectronic separators, and air jigs are all mature industrial equipment, which are easy to integrate into existing production lines and suitable for large-scale promotion. Meanwhile, this treatment method is designed for low-grade (A / S ≤ 3), high-silicon (SiO 2 ≥ 20%) bauxite, and can process raw ore containing complex gangue minerals (such as kaolinite and pyrophyllite), expanding the scope of resource utilization.

[0069] The following further elaborates on this application in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate this application and not to limit the scope of this application. The experimental methods without specific conditions noted in the following embodiments are usually determined according to industry standards. If there is no corresponding industry standard, they are carried out according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0070] Example 1

[0071] A high-silicon bauxite. Among them, the raw ore Al2 O 3 The content of O is 52.20%, and the content of SiO 2 is 20.86%, and the content of Fe 2 O 3 is 6.73%, and the aluminum-silicon ratio is 2.50.

[0072] The original ore is subjected to a primary classification treatment to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on the belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and enters the XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV, and the sorting gray value is 10,000, to obtain preselected concentrate and preselected tailings; the preselected tailings are combined with the -20 mm sized ore for crushing and secondary classification treatment to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jig under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 90 mm to obtain coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for a primary electrostatic impurity removal, and under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm, primary electrostatic separation concentrate and primary electrostatic separation tailings are obtained. The primary electrostatic separation concentrate is subjected to a secondary electrostatic impurity removal, and under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm, secondary electrostatic separation concentrate and secondary electrostatic separation tailings are obtained. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-grained tailings; the preselected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined into concentrate, and the coarse-grained tailings and the fine-grained tailings are combined into tailings.

[0073] Example 2

[0074] A high-silica bauxite ore. Among them, the content of Al 2 O 3 in the original ore is 50.54%, the content of SiO 2 is 19.21%, the content of Fe 2 O 3 is 10.49%, and the aluminum-silicon ratio is 2.63.

[0075] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on the belt by a vibrating feeder under the condition of a vibration frequency of 20 Hz and enters an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 85 kV and the sorting gray value is 9900, obtaining pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigger under the conditions of an air flow velocity of 2.5 m / s, a vibration frequency of 370 times / min, an amplitude of 5 mm, and a bed layer thickness of 80 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-grained tailings; the pre-selected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined into concentrate, and the coarse-grained tailings and the fine-grained tailings are combined into tailings.

[0076] Example 3

[0077] A high-silica bauxite ore. The raw ore contains Al 2 O 3 with a content of 51.26%, SiO 2 with a content of 20.13%, Fe 2 O 3 with a content of 9.26%, and the aluminum-silicon ratio is 2.55.

[0078] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and fed into an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10200, to obtain preselected concentrate and preselected tailings; the preselected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jig under the conditions of an air flow velocity of 2.0 m / s, a vibration frequency of 350 times / min, an amplitude of 5 mm, and a bed layer thickness of 90 mm to obtain coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, and under the conditions of a voltage of 25 kV, an electrode spacing of 60 mm, and a drum rotation speed of 90 rpm, primary electrostatic separation concentrate and primary electrostatic separation tailings are obtained. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, and under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm, secondary electrostatic separation concentrate and secondary electrostatic separation tailings are obtained. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined as the fine-grained tailings; the preselected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined as the concentrate, and the coarse-grained tailings and the fine-grained tailings are combined as the tailings.

[0079] Example 4

[0080] A high-silica bauxite ore. The raw ore contains Al 2 O 3 with a content of 48.37%, SiO 2 with a content of 22.12%, Fe 2 O 3 with a content of 8.79%, and an aluminum-silicon ratio of 2.19.

[0081] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 23 Hz and fed into an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 100 kV and the sorting gray value is 10,000, obtaining preselected concentrate and preselected tailings; the preselected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigger under the conditions of an air flow velocity of 2.5 m / s, a vibration frequency of 400 times / min, an amplitude of 7 mm, and a bed layer thickness of 100 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 65 mm, and a drum rotation speed of 80 rpm. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 25 kV, an electrode spacing of 70 mm, and a drum rotation speed of 130 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-grained tailings; the preselected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined into concentrate, and the coarse-grained tailings and the fine-grained tailings are combined into tailings.

[0082] Example 5

[0083] A high-silica bauxite ore. The raw ore contains Al 2 O 3 with a content of 49.89%, SiO 2 with a content of 19.92%, Fe 2 O 3 with a content of 10.03%, and an aluminum-silicon ratio of 2.50.

[0084] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and fed into an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, obtaining pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigger under the conditions of an air flow velocity of 2.3 m / s, a vibration frequency of 300 times / min, an amplitude of 5 mm, and a bed layer thickness of 900 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 25 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 35 kV, an electrode spacing of 75 mm, and a drum rotation speed of 110 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-grained tailings; the pre-selected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined into concentrate, and the coarse-grained tailings and the fine-grained tailings are combined into tailings.

[0085] Comparative Example 1

[0086] A high-silica bauxite ore. The raw ore contains 2 O 3 with a content of 52.20%, and 2 SiO 2 O 3 with a content of 20.86%,

[0087] The raw ore is subjected to primary classification to obtain -100 + 50 mm sized ore and -50 mm sized ore; the -100 + 50 mm sized ore is spread on the belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and enters the XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10200, obtaining pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -50 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jig under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 90 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-grained tailings; the pre-selected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined into concentrate, and the coarse-grained tailings and the fine-grained tailings are combined into tailings.

[0088] Comparative Example 2

[0089] A high-silica bauxite. The raw ore contains Al 2 O 3 with a content of 52.20%, SiO 2 with a content of 20.86%, Fe 2 O 3 with a content of 6.73%, and the aluminum-silicon ratio is 2.50.

[0090] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and fed into an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, to obtain pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -20 mm sized ore and subjected to crushing and secondary classification to obtain the coarse-sized -5 + 0.5 mm ore and the fine-sized -0.5 mm ore; the -5 + 0.54 mm ore enters a wind jigs under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 90 mm, to obtain coarse-sized concentrate and coarse-sized tailings; the -0.5 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, and under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm, primary electrostatic separation concentrate and primary electrostatic separation tailings are obtained. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, and under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm, secondary electrostatic separation concentrate and secondary electrostatic separation tailings are obtained. The secondary electrostatic separation concentrate is the fine-sized concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined into fine-sized tailings; the pre-selected concentrate, the coarse-sized concentrate, and the fine-sized concentrate are combined into concentrate, and the coarse-sized tailings and the fine-sized tailings are combined into tailings.

[0091] Comparative Example 3

[0092] A high-silica bauxite ore. The raw ore contains Al 2 O 3 with a content of 52.20%, SiO 2 with a content of 20.86%, Fe 2 O 3 with a content of 6.73%, and an aluminum-silicon ratio of 2.50.

[0093] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and fed into an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, obtaining pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigger under the conditions of an air flow velocity of 3 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 120 mm to obtain coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate undergoes secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined as the fine-grained tailings; the pre-selected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined as the concentrate, and the coarse-grained tailings and the fine-grained tailings are combined as the tailings.

[0094] Comparative Example 4

[0095] A high-silica bauxite ore. The raw ore contains 2 O 3 with a content of 52.20%, SiO 2 with a content of 20.86%, Fe 2 O 3 with a content of 6.73%, and the aluminum-silicon ratio is 2.50.

[0096] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on the belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and enters the XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, obtaining pre-selected concentrate and pre-selected tailings; the pre-selected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigs under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 500 times / min, an amplitude of 8 mm, and a bed layer thickness of 90 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 20 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate undergoes secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined as the fine-grained tailings; the pre-selected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined as the concentrate, and the coarse-grained tailings and the fine-grained tailings are combined as the tailings.

[0097] Comparative Example 5

[0098] A high-silica bauxite. The raw ore contains Al 2 O 3 with a content of 52.20%, SiO 2 with a content of 20.86%, Fe 2 O 3 with a content of 6.73%, and the aluminum-silicon ratio is 2.50.

[0099] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on the belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and enters an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, obtaining preselected concentrate and preselected tailings; the preselected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jig under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 90 mm, obtaining coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum-type electrostatic separator for primary electrostatic impurity removal, obtaining primary electrostatic separation concentrate and primary electrostatic separation tailings under the conditions of a voltage of 30 kV, an electrode spacing of 65 mm, and a drum rotation speed of 100 rpm. The primary electrostatic separation concentrate undergoes secondary electrostatic impurity removal, obtaining secondary electrostatic separation concentrate and secondary electrostatic separation tailings under the conditions of a voltage of 40 kV, an electrode spacing of 75 mm, and a drum rotation speed of 120 rpm. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined as the fine-grained tailings; the preselected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined as the concentrate, and the coarse-grained tailings and the fine-grained tailings are combined as the tailings.

[0100] Comparative Example 6

[0101] A high-silica bauxite ore. The raw ore contains Al 2 O 3 with a content of 52.20%, SiO 2 with a content of 20.86%, Fe 2 O 3 with a content of 6.73%, and the aluminum-silicon ratio is 2.50.

[0102] The raw ore is subjected to primary classification to obtain -50 + 20 mm sized ore and -20 mm sized ore; the -50 + 20 mm sized ore is evenly spread on a conveyor belt by a vibrating feeder under the condition of a vibration frequency of 25 Hz and enters an XRT optoelectronic separator for pretreatment. The X-ray light source intensity is 90 kV and the sorting gray value is 10,000, to obtain preselected concentrate and preselected tailings; the preselected tailings are combined with the -20 mm sized ore for crushing and secondary classification to obtain the coarse-grained -3 + 0.15 mm ore and the fine-grained -0.15 mm ore; the -3 + 0.15 mm ore enters a wind jigs under the conditions of an air flow velocity of 2.2 m / s, a vibration frequency of 350 times / min, an amplitude of 6 mm, and a bed layer thickness of 90 mm to obtain coarse-grained concentrate and coarse-grained tailings; the -0.15 mm ore enters a drum type electrostatic separator for primary electrostatic impurity removal, and under the conditions of a voltage of 45 kV, an electrode spacing of 65 mm, and a drum rotation speed of 120 rpm, primary electrostatic separation concentrate and primary electrostatic separation tailings are obtained. The primary electrostatic separation concentrate is subjected to secondary electrostatic impurity removal, and under the conditions of a voltage of 35 kV, an electrode spacing of 75 mm, and a drum rotation speed of 150 rpm, secondary electrostatic separation concentrate and secondary electrostatic separation tailings are obtained. The secondary electrostatic separation concentrate is the fine-grained concentrate, and the primary electrostatic separation tailings and the secondary electrostatic separation tailings are combined as fine-grained tailings; the preselected concentrate, the coarse-grained concentrate, and the fine-grained concentrate are combined as concentrate, and the coarse-grained tailings and the fine-grained tailings are combined as tailings.

[0103] The contents of the concentrate and tailings of Examples 1 to 5 and Comparative Examples 1 to 6 were measured, and the results are shown in Table 1.

[0104] Table 1 Contents of the raw ore, concentrate, and tailings of Examples 1 to 5 and Comparative Examples 1 to 6

[0105]

[0106]

[0107] From the data comparison between Example 1 and Comparative Example 1, it can be seen that by changing the particle size of the raw ore, due to insufficient X-ray light source intensity, the X-ray will not be able to penetrate the ore due to insufficient energy, and then aluminum minerals will be misjudged as silicon minerals, thus affecting the effect of optoelectronic separation; at the same time, due to the too large particle size of the raw ore, the poor dissociation degree of the ore will also affect the separation effect.

[0108] From the data comparison between Example 1 and Comparative Example 2, it can be seen that by changing the classification particle size of the coarse and fine particle sizes and increasing the particle sizes of the wind jigs and the drum type electrostatic separator, it directly affects the final concentrate and tailings indexes. The main reason is that the embedding relationship between aluminum minerals and silicon minerals in bauxite is complex and the embedding particle size is relatively fine. Under the condition of a relatively coarse particle size, the minerals are not fully dissociated, the aluminum-silicon ratio of the tailings is relatively high, and the aluminum-silicon ratio of the concentrate is relatively low during the separation process, directly affecting the separation effect.

[0109] From the data comparison between Example 1 and Comparative Example 3, it can be seen that increasing the air flow velocity and bed layer thickness will directly affect the final concentrate and tailings indexes. This is mainly because too large an air flow velocity will cause both light and heavy minerals to be blown away, affecting the separation effect; too large a bed layer thickness will cause incomplete stratification of light and heavy minerals, affecting the separation effect.

[0110] From the data comparison between Example 1 and Comparative Example 4, it can be seen that increasing the vibration frequency and amplitude affects the separation indexes of concentrate and tailings. This is mainly because too large an air flow velocity will cause both light and heavy minerals to be blown away, affecting the separation effect; too large a bed layer thickness will cause incomplete stratification of light and heavy minerals, affecting the separation effect.

[0111] From the data comparison between Example 1 and Comparative Example 5, it can be seen that increasing the electrostatic separation voltage affects the separation indexes of concentrate and tailings. This is mainly because when the voltage is too high, aluminum minerals will be overcharged and adsorbed into the tailings, affecting the separation effect.

[0112] From the data comparison between Example 1 and Comparative Example 6, it can be seen that increasing the drum rotation speed will affect the separation indexes of concentrate and tailings. This is mainly because after the drum rotation speed increases, aluminum minerals will be subjected to a greater centrifugal force and adhere to the drum and finally fall into the tailings, thus affecting the separation effect.

[0113] In addition, one or more technical solutions in the embodiments of the present application at least further have the following technical effects or advantages:

[0114] In the embodiments of the present application, the process of "primary classification pretreatment - crushing and secondary classification - coarse-grained wind re-selection - fine-grained electrostatic separation" is adopted. After treatment, the low-grade high-silicon bauxite can obtain aluminum concentrate with high alumina content, relatively high aluminum-silicon ratio, and relatively low impurity content. It has the characteristics of low operating cost, simple process, and no addition of any chemical reagents throughout the process. The concentrate is suitable for the production of alumina by the Bayer process, and the tailings contain no reagents and are neutral, so they can be safely stacked or backfilled into the mine.

[0115] In the embodiments of the present application, the dry gravity separation method for high-silicon bauxite can effectively reduce the ore consumption for producing alumina from low-grade bauxite, reduce the amount of red mud, and at the same time improve the resource utilization rate in China.

[0116] In the embodiments of the present application, the dry gravity separation method for high-silicon bauxite can effectively separate silicon minerals and aluminum minerals in bauxite, reduce production costs, improve the ore grade, realize the efficient and high-value utilization of bauxite resources, and has significant social and economic benefits.

[0117] In the embodiments of the present application, the dry gravity separation method for high-silicon bauxite has the characteristics of short process, low energy consumption, low production cost, and low investment. It can effectively improve the quality of bauxite and can be directly used for the production of alumina by the Bayer process.

[0118] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A dry gravity separation method for treating high-silicon bauxite, the method comprising: The raw ore is subjected to a primary classification to obtain a first coarse-grained ore and a first fine-grained ore; The first coarse-grained ore is subjected to vibration feeding and photoelectric separation for pre-processing to obtain pre-selected concentrate and pre-selected tailings; The first fine-grained ore and the pre-selected tailings are combined for crushing and secondary classification to obtain a second coarse-grained ore and a second fine-grained ore; The second coarse-grained ore is subjected to wind separation to obtain a coarse-grained concentrate and a coarse-grained tailings; The second fine-grained ore is subjected to electric separation to obtain fine-grained concentrate and fine-grained tailings; combining the coarse-grained concentrate, the fine-grained concentrate and the pre-treated concentrate into a concentrate; as well as The coarse-grained tailings and the fine-grained tailings are combined into tailings.

2. The method according to claim 1, characterized in that The raw ore meets the following conditions: Al2O3 mass fraction ≥45.00%, SiO2 mass fraction ≥20.00%, A / S ≤3, and particle size ≤50 mm.

3. The method according to claim 1, characterized in that: The particle size of the first coarse-grained ore is -50+20 mm, and the particle size of the first fine-grained ore is -20 mm.

4. The method according to claim 1, characterized in that The vibrating feeder uses a vibrating feeder, the vibration frequency of the vibrating feeder is 25 Hz, and the discharging end of the vibrating feeder is a conical discharging port.

5. The method according to claim 1, characterized in that The photoelectric sorting uses an XRT photoelectric sorting machine, the photoelectric sorting adopts X-ray projection sorting technology, and the light source intensity of the photoelectric sorting is 80kV to 100kV.

6. The method according to claim 5, characterized in that In the photoelectric sorting technology, the sorting threshold f is 10000±200; wherein, When f≥10000, pre-selected tailings are obtained by sorting; When f<10000, pre-selected concentrate is obtained by sorting.

7. The method according to claim 1, characterized in that The particle size of the second coarse-grained ore is -3+0.15 mm, and the particle size of the second fine-grained material is -0.15 mm.

8. The method according to claim 1, characterized in that The wind separation uses a wind jig, which meets the following conditions: air flow velocity of 2.0m / s-2.5m / s, vibration frequency of 300 times / min-400 times / min, amplitude of 5mm-8mm, and bed thickness of 80mm-100mm.

9. The method according to claim 1, characterized in that: The electric power separation uses a drum-type electric separation machine, and the number of times of the electric power separation is ≥2 times.

10. The method according to claim 9, characterized in that The drum type electrostatic separator meets the following conditions: the motor polarity is a negative corona electrode, the voltage is 20kV to 35kV, the motor spacing is 60mm to 80mm, and the drum speed is 90rpm to 130rpm.

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