Method for full-quantitative utilization of bauxite ore washing tailings

Abstract

The invention provides a method for full-quantitative utilization of bauxite ore washing tailings, and belongs to the field of comprehensive utilization of colored resources. The method comprises the steps that the aluminum washing tailings are stirred, pulped and scrubbed, and ore pulp is obtained; the ore pulp is subjected to impurity removal and screening, and a first aluminum-containing material and a first fine particle material are obtained; scrubbing and screening the first aluminum-containing material to obtain a second aluminum-containing material and a second fine particle material; the first fine-particle material and the second fine-particle material are combined and then reselected through a shaking table, and a third aluminum-containing material and a third fine-particle material are obtained; the third fine particle material is subjected to centrifugal reselection, and a fourth aluminum-containing material and a fourth fine particle material are obtained; the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material are combined and then subjected to high-gradient magnetic separation, and aluminum concentrate ore pulp and magnetic material ore pulp are obtained; the magnetic material ore pulp and the fourth fine particle material are combined, and tailing ore pulp is obtained; the aluminum concentrate pulp and the tailing pulp are concentrated and then subjected to powerful dehydration, and aluminum concentrate, tailings and backwater are obtained respectively. The method can improve the comprehensive utilization rate of the washing tailings.

Description

Technical Field

[0001] This application relates to the technical field of comprehensive utilization of non-ferrous resources, and particularly relates to a method for the full-quantification utilization of bauxite washing tailings. Background Art

[0002] Bauxite is the main raw material for producing alumina. During the development and utilization of bauxite resources, a large amount of beneficiation tailings are generated. Its tailing pond not only occupies land and pollutes the environment, but also has huge potential safety hazards. At the same time, the tailings also contain a large amount of valuable components, resulting in waste of resources. However, due to factors such as high fine particle content, high flocculant content, and long stacking time in the bauxite washing tailings in the tailing pond, it is difficult to recover the aluminum-containing ore in it by conventional processes, and thus it is difficult to achieve full-quantification utilization.

[0003] Currently, the methods for the utilization of bauxite washing tailings include: (1) A method for simultaneously recovering aluminum and iron from bauxite beneficiation tailings and preparing high-silicate slag. This method includes: drying and grinding bauxite tailings, adding concentrated sulfuric acid and mixing evenly to form spheres, then heating and roasting, continuously adding concentrated sulfuric acid during the roasting process, leaching the roasted bauxite tailings spheres with washing liquid, and the filtrate obtained after filtration is the primary acid leaching solution, and the filter cake obtained after washing and filtration is the high-silicate slag, and the obtained washing liquid is used as the leaching solution for the roasted bauxite tailings spheres next time; neutralizing the primary acid leaching solution with ground tailings, and the filtrate obtained after filtration is the solution containing aluminum sulfate and iron sulfate. (2) A dry treatment method for bauxite tailings. This method includes: first sending the washed tailing sand into the first hydrocyclone group for hydrocyclone separation to obtain the first coarse sand and the first overflow; screening the first coarse sand to obtain the first undersize and the first oversize; sending the first undersize and the first overflow into the second hydrocyclone group for hydrocyclone separation to obtain the second overflow and the second coarse sand; sending the first oversize and the second coarse sand into a desiliconizer for desiliconization to obtain the third overflow and the third coarse sand; screening the third coarse sand to obtain the second undersize and the second oversize; thickening the third overflow, the second overflow, and the second undersize to obtain the fourth overflow and the underflow; adding a flocculant to the underflow, mixing evenly, and filtering to obtain the filtrate and the filter cake. (3) A method for re-beneficiation of bauxite beneficiation tailings. This method includes: first grinding the bauxite beneficiation tailings, then adjusting the pulp, adding regulators, inhibitors, and collectors for full mixing and high-pressure mineralization, and performing flotation at a temperature of 40 - 70 °C using a non-driven flotation cell, so that the diaspore minerals float up through the foam carrier, and the gangue minerals remain in the pulp. Summary of the Invention

[0004] This application provides a method for the full-quantification utilization of bauxite washing tailings to solve the following technical problems: how to improve the quality, recovery rate, and comprehensive utilization rate of the aluminum concentrate recovered from bauxite washing tailings.

[0005] An embodiment of the present application provides a method for the full utilization of bauxite washing tailings, and the method includes:

[0006] Stir and pulp the bauxite washing tailings and perform primary strong scrubbing to obtain a dispersed pulp;

[0007] Remove impurities from the dispersed pulp to obtain the pulp to be beneficiated and wood chip impurities respectively;

[0008] Perform primary screening on the pulp to be beneficiated to obtain a first aluminum-containing material and a first fine-grained material;

[0009] Perform secondary strong scrubbing and secondary screening on the first aluminum-containing material to obtain a second aluminum-containing material and a second fine-grained material;

[0010] Merge the first fine-grained material and the second fine-grained material and perform table concentration to obtain a third aluminum-containing material and a third fine-grained material;

[0011] Perform centrifugal concentration on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material;

[0012] Merge the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain an aluminum concentrate pulp and a magnetic material pulp;

[0013] Merge the magnetic material pulp and the fourth fine-grained material to obtain a tailing pulp;

[0014] Concentrate the aluminum concentrate pulp and the tailing pulp and perform strong dehydration to obtain aluminum concentrate, tailings and recycled water respectively.

[0015] Optionally, in terms of mass fraction, the chemical composition of the bauxite washing tailings satisfies: Al 2 O 3 content ≥ 35.00%, Fe 2 O 3 content ≤ 30.00%, A / S ≤ 3. More than 85% of the aluminum minerals in the bauxite washing tailings exist in the form of diaspore, and the bauxite washing tailings are piled up in a plate-like shape in the tailing pond.

[0016] Optionally, both the primary strong scrubbing and the secondary strong scrubbing use a bucket-wheel scrubber;

[0017] The series scrubbing process of the primary strong scrubbing and the secondary strong scrubbing is 2 to 3 stages;

[0018] The pulp concentration of the primary strong scrubbing and the secondary strong scrubbing is 20 - 40%.

[0019] Optionally, a vibrating slag separator is used for impurity removal, and the screen aperture of the vibrating slag separator is 5 mm to 2 mm;

[0020] Both the primary screening and the secondary screening use a linear screen, and the screen aperture of the linear screen is 0.1 mm to 0.2 mm.

[0021] Optionally, the following parameters are included in the shaking table gravity separation: the slope is 0.8° to 1.5°, the stroke is 10 mm to 12 mm, and the impulse frequency is 280 times / min to 310 times / min.

[0022] Optionally, a centrifugal concentrator is used for centrifugal gravity separation, the drum rotation speed of the centrifugal concentrator is 950 revolutions / min to 1150 revolutions / min, and the drum inclination angle of the centrifugal concentrator is 4° to 8°.

[0023] Optionally, the magnetic field intensity of the high-gradient magnetic separation is 4000 GS to 8000 GS, the magnetic separation medium of the high-gradient magnetic separation is 2 mm steel bars with a filling rate of 10% to 15%, and the pulsating water impulse frequency of the high-gradient magnetic separation is 145 times / min to 165 times / min.

[0024] Optionally, an intelligent pressure filter is used for strong dehydration, the working pressure of the intelligent pressure filter is 0.30 MPa to 0.60 MPa, and the feed concentration of the intelligent pressure filter is 35% to 50%.

[0025] Optionally, by mass fraction, the moisture content of the aluminum concentrate is ≤ 12%, and the moisture content of the tailings is ≤ 20%.

[0026] Optionally, after obtaining the aluminum concentrate, tailings and recycled water, the method further includes:

[0027] The recycled water is returned to the stirring and pulping step for recycling;

[0028] The tailings are mixed with the mining waste rock crushed to a preset particle size in a predetermined ratio to obtain soil for mine area soil remediation; the preset particle size is 3 mm to 5 mm, and the predetermined ratio is tailings: crushed waste rock = 2:1 to 1:1.

[0029] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0030] An embodiment of the present application provides a method for the full quantification utilization of bauxite washing tailings. The method includes: stirring and pulping the bauxite washing tailings and performing primary strong scrubbing to obtain a dispersed pulp; removing impurities from the dispersed pulp to obtain a pulp to be beneficiated and wood chip impurities respectively; performing primary screening on the pulp to be beneficiated to obtain a first aluminum-containing material and a first fine-grained material; performing secondary strong scrubbing and secondary screening on the first aluminum-containing material to obtain a second aluminum-containing material and a second fine-grained material; combining the first fine-grained material and the second fine-grained material and performing table concentration to obtain a third aluminum-containing material and a third fine-grained material; performing centrifugal concentration on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material; combining the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and performing high-gradient magnetic separation to obtain an aluminum concentrate pulp and a magnetic material pulp; combining the magnetic material pulp and the fourth fine-grained material to obtain a tailing pulp; and concentrating and strongly dehydrating the aluminum concentrate pulp and the tailing pulp to obtain aluminum concentrate, tailings and recycled water respectively. On the one hand, by adopting a process of staged scrubbing - staged concentration for the washing tailings, the problems of difficult dispersion and dissociation of the washing tailings are solved, laying a foundation for obtaining aluminum concentrate with better grade and recovery rate subsequently; on the other hand, through the combination of four processes of linear screen screening + slime table concentration + centrifugal beneficiation concentration + magnetic separation, the technical problems that a qualified aluminum concentrate cannot be obtained by using a single concentration technology and the loss of fine-grained aluminum-containing minerals is serious are solved. Thus, a technology for the full quantification utilization of bauxite washing tailings in a tailing pond is formed through staged scrubbing - staged concentration + high-gradient magnetic separation, solving the problems of poor quality of aluminum concentrate, low recovery rate and low comprehensive utilization rate existing in the recovery of bauxite washing tailings in the tailing pond in the prior art. Description of the Drawings

[0031] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in 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, other drawings can also be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a flow schematic diagram of a method for the full quantification utilization of bauxite washing tailings provided by an embodiment of the present application. Detailed Embodiments

[0034] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the following will, with reference to the accompanying drawings in the embodiments of this application, clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0035] 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., and 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.

[0036] In addition, in the description of the specification of the present application, terms such as "include" and "comprise" 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, indicating that there can be three relationships. 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 "a plurality" means two or more. "At least one kind", "at least one of the following (items)" or similar expressions refer to any combination of these items, including any combination of single item (s) or plural item (s). For example, "at least one of a, b, or c", or, "at least one of 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. The "parts representation method" such as parts by weight and parts by mass represents the proportional relationship between each component. In the proportional relationships involved in this text, the parameters that need to be described by proportion should be understood as the antecedents of the proportion formula in the order of description, and the proportional numbers should be understood as the consequents of the proportion 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 proportional numbers in the proportion 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.

[0037] 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.

[0038] It should be noted that for the prior art (1) described in the background art, the inventors found that although this method realizes the enrichment and impurity removal of silicon, there are problems such as complex process, high cost, and high acid consumption; for the prior art (2) described in the background art, the inventors found that although this method can recover some aluminous minerals, there are problems such as low grade and recovery rate of aluminum concentrate and high moisture content of filter cake. At the same time, it is found that this method is for the unfiltered washing tailings and has poor effect on the filtered washing tailings; for the prior art (3) described in the background art, the inventors found that there are still problems such as difficult reclamation water treatment, low alumina content in aluminum concentrate, and low alumina recovery rate when using the method provided by this invention.

[0039] Figure 1 It is a process schematic diagram of a method for the full - quantification utilization of bauxite washing tailings provided by an embodiment of the present application.

[0040] As Figure 1 shown, the present application provides a method for fully utilizing bauxite washing tailings, and the method includes:

[0041] S1. Stir and pulp the bauxite washing tailings and perform primary strong scrubbing to obtain a dispersed pulp;

[0042] S2. Remove impurities from the dispersed pulp to obtain a pulp to be beneficiated and wood chip impurities respectively;

[0043] S3. Perform primary screening on the pulp to be beneficiated to obtain a first aluminum-containing material and a first fine-grained material;

[0044] S4. Perform secondary strong scrubbing and secondary screening on the first aluminum-containing material to obtain a second aluminum-containing material and a second fine-grained material;

[0045] S5. Combine the first fine-grained material and the second fine-grained material and perform table concentration to obtain a third aluminum-containing material and a third fine-grained material;

[0046] S6. Perform centrifugal concentration on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material;

[0047] S7. Combine the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain an aluminum concentrate pulp and a magnetic material pulp;

[0048] S8. Combine the magnetic material pulp and the fourth fine-grained material to obtain a tailing pulp;

[0049] S9. Concentrate the aluminum concentrate pulp and the tailing pulp and perform strong dehydration to obtain aluminum concentrate, tailings and recycled water respectively.

[0050] In some embodiments, in terms of mass fraction, the chemical composition of the bauxite washing tailings satisfies: Al 2 O 3 content ≥ 35.00%, Fe 2 O 3 content ≤ 30.00%, A / S ≤ 3. More than 85% of the aluminum minerals in the bauxite washing tailings exist in the form of diaspore, and the bauxite washing tailings are stacked in a compacted state in the tailing pond.

[0051] In the embodiments of the present application, the bauxite washing tailings are stacked in a compacted state in the tailing pond. By refining the Al 2 O 3 content, A / S value, and Fe 2 O 3The content range defines the raw material range of the bauxite washing tailings, and then high-grade bauxite concentrate and soil ponds for soil remediation in the mining area can be obtained subsequently, indicating the applicable range and feasibility of the method of this application. If the content of Al 2 O 3 , the value of A / S, and the content of Fe 2 O 3 are too low, the bauxite washing tailings have no value for development and utilization.

[0052] In some embodiments, both the first strong scrubbing and the second strong scrubbing use a bucket-wheel scrubber;

[0053] The series scrubbing process of the first strong scrubbing and the second strong scrubbing is 2 to 3 stages;

[0054] The pulp concentration of the first strong scrubbing and the second strong scrubbing is 20 - 40%.

[0055] In the embodiments of this application, by defining the specific type of the scrubbing equipment and the specific process of the first scrubbing and the second scrubbing, the compact bauxite washing tailings from the tailings pond can be better dispersed and dissociated, providing favorable conditions for subsequent separation. When the process values of the first scrubbing and the second scrubbing are too large, although high-quality bauxite concentrate can be obtained, the complexity of the process and the production cost will increase; when the process values of the first scrubbing and the second scrubbing are too small, the incomplete scrubbing will lead to incomplete dispersion of the bauxite concentrate and gangue minerals, thereby deteriorating the quality of the bauxite concentrate.

[0056] The series scrubbing process of the first scrubbing and the second scrubbing can be 2 stages or 3 stages.

[0057] In the embodiments of this application, by defining the specific pulp concentration of the first scrubbing and the second scrubbing, the compact bauxite washing tailings from the tailings pond can be better dispersed and dissociated, providing favorable conditions for subsequent screening by a straight-line screen and obtaining high-grade bauxite concentrate. When the pulp concentration values of the first scrubbing and the second scrubbing are too large, the incomplete scrubbing will lead to incomplete dispersion of the bauxite concentrate and gangue minerals, thereby deteriorating the quality of the bauxite concentrate; when the pulp concentration values of the first scrubbing and the second scrubbing are too small, although high-quality bauxite concentrate can be obtained, the process throughput will be reduced.

[0058] The pulp concentration for the first scrubbing and the second scrubbing can be 20%, or 21%, or 22%, or 23%, or 24%, or 25%, or 26%, or 27%, or 28%, or 29%, or 30%, or 31%, or 32%, or 33%, or 34%, or 35%, or 36%, or 37%, or 38%, or 39%, or 40%.

[0059] In some embodiments, a vibrating slag screen is used for impurity removal, and the screen aperture of the vibrating slag screen is 5 mm to 2 mm;

[0060] Both the first screening and the second screening use a linear screen, and the screen aperture of the linear screen is 0.1 mm to 0.2 mm.

[0061] In the embodiments of the present application, by controlling the specific particle size of the screen of the vibrating slag screen, waste rocks with larger particle sizes and sundries such as plant wood chips mixed on the surface of the washed tailings can be separated out. Therefore, impurities such as wood chips can be removed from the bauxite washed tailings by screening and classification, avoiding the entry of impurities into the beneficiation process and affecting the quality of the aluminum concentrate to facilitate the subsequent alumina digestion operation of the aluminum concentrate. When the value of the screen aperture is too large, waste rocks and impurities such as wood chips will enter the separation process due to the too large screen aperture, affecting the quality of the aluminum concentrate. When the value of the screen aperture is too small, part of the aluminum concentrate will be lost in the wood chips, and at the same time, it will affect the processing capacity of the slag screen, resulting in a decrease in the recovery rate of the aluminum concentrate.

[0062] The screen aperture can be 2 mm, or 2.5 mm, or 3.5 mm, or 3.5 mm, or 3.5 mm, or 4 mm, or 4.5 mm, or 5.0 mm.

[0063] In the embodiments of the present application, by controlling the specific aperture of the screen of the linear screen, diaspore with larger particle sizes and better dispersion and dissociation can be separated out, and feed materials for table concentrator gravity separation and centrifugal gravity separation are provided. When the value of the screen aperture is too large, part of the aluminum-containing minerals with good dispersion and dissociation will be lost in the undersize minerals, affecting the analysis effect of table concentrator gravity separation. When the value of the screen aperture is too small, although the yield of the aluminum concentrate can be increased, at the same time, the screening efficiency of the linear screen and the quality of the aluminum concentrate will be reduced.

[0064] The screen aperture of the linear screen can be 0.10 mm, or 0.12 mm, or 0.14 mm, or 0.16 mm, or 0.18 mm, or 0.20 mm.

[0065] In some embodiments, the shaking table gravity separation includes the following parameters: the slope is 0.8° to 1.5°, the stroke is 10 mm to 12 mm, and the stroke frequency is 280 times / min to 310 times / min.

[0066] In the embodiments of the present application, by controlling the equipment type for the shaking table gravity separation, the specific values of the slope, stroke, and stroke frequency of the shaking table gravity separation, the best shaking table gravity separation effect can be obtained. When the bed surface slope value of the shaking table gravity separation is too large, it will reduce the recovery rate of aluminum concentrate because some coarse-grained aluminum-containing concentrate is lost in the tailings. When the slope value of the shaking table gravity separation is too small, it will cause some tailings to enter the aluminum concentrate and reduce the alumina content of the aluminum concentrate. When the stroke value of the shaking table gravity separation is too large, the stratification speed of the material on the bed surface will be accelerated, resulting in some coarse-grained aluminum-containing concentrate being lost in the tailings and reducing the recovery rate of the aluminum concentrate. When the stroke value of the shaking table gravity separation is too small, the stratification speed of the material on the bed surface will be reduced, resulting in some tailings entering the aluminum concentrate and reducing the alumina content of the aluminum concentrate. When the stroke frequency value of the shaking table gravity separation is too large, the stratification speed of the material on the bed surface will be accelerated, resulting in some coarse-grained aluminum-containing concentrate being lost in the tailings and reducing the recovery rate of the aluminum concentrate. At the same time, it will also reduce the service life of the equipment. When the stroke frequency value of the shaking table gravity separation is too small, the stratification speed of the material on the bed surface will be reduced, resulting in some tailings entering the aluminum concentrate and reducing the alumina content of the aluminum concentrate.

[0067] The slope of the shaking table gravity separation can be 0.8°, or 0.9°, or 1.0°, or 1.1°, or 1.2°, or 1.3°, or 1.4°, or 1.5°.

[0068] The stroke of the shaking table gravity separation can be 10 mm, or 11 mm, or 12 mm.

[0069] The stroke frequency of the shaking table gravity separation can be 280 times / min, or 285 times / min, or 290 times / min, or 295 times / min, or 300 times / min, or 305 times / min, or 310 times / min.

[0070] In some embodiments, the centrifugal gravity separation uses a centrifugal concentrator, the drum rotation speed of the centrifugal concentrator is 950 revolutions / min to 1150 revolutions / min, and the drum inclination angle of the centrifugal concentrator is 4° to 8°.

[0071] In the embodiments of the present application, by controlling the type of equipment for centrifugal gravity separation, the rotational speed of the drum of the centrifugal concentrator, and the specific values of the inclination angle of the drum of the centrifugal concentrator, aluminum concentrate with better grade and recovery rate can be obtained. When the rotational speed of the drum of the centrifugal concentrator is too large, the centrifugal force will increase, which will cause some tailings to enter the aluminum concentrate and reduce the alumina content of the aluminum concentrate. When the rotational speed of the drum of the centrifugal concentrator is too small, the centrifugal force will weaken, and some aluminum-containing minerals cannot be recovered, resulting in the loss of some coarse-grained aluminum-containing concentrate in the tailings and reducing the recovery rate of the aluminum concentrate. When the inclination angle of the drum of the centrifugal concentrator is too large, the residence time and friction force of the separated minerals on the drum surface will become smaller, resulting in the loss of some coarse-grained aluminum-containing concentrate in the tailings and reducing the yield and recovery rate of the aluminum concentrate. When the inclination angle of the drum of the centrifugal concentrator is too small, the residence time and friction force of the separated minerals on the drum surface will become larger, which will cause some tailings to enter the aluminum concentrate and reduce the alumina content of the aluminum concentrate.

[0072] The rotational speed of the drum of the centrifugal concentrator can be 950 r / min, or 960 r / min, or 970 r / min, or 980 r / min, or 990 r / min, or 1000 r / min, or 1010 r / min, or 1020 r / min, or 1030 r / min, or 1040 r / min, or 1050 r / min, or 1060 r / min, or 1070 r / min, or 1080 r / min, or 1090 r / min, or 1110 r / min, or 1120 r / min, or 1130 r / min, or 1140 r / min, or 1150 r / min.

[0073] The inclination angle of the drum of the centrifugal concentrator can be 4°, or 4.5°, or 5°, or 5.5°, or 6°, or 6.5°, or 7°, or 7.5°, or 8°.

[0074] In some embodiments, the magnetic field strength of the high-gradient magnetic separation is 4000 GS to 8000 GS, the magnetic separation medium of the high-gradient magnetic separation is 2 mm steel rods with a filling rate of 10% to 15%, and the pulsating water flushing frequency of the high-gradient magnetic separation is 145 times / min to 165 times / min.

[0075] In the embodiments of the present application, by controlling the specific values of the magnetic field strength for high-gradient magnetic separation, the filling rate of the magnetic separation medium, and the number of pulsating water flushes, a better magnetic separation and impurity removal effect can be achieved, and aluminum concentrate with better grade and recovery rate can be obtained. When the magnetic field strength is too large, due to the excessive field strength, aluminum-containing minerals will be mixed into magnetic minerals, resulting in a decrease in the recovery rate of aluminum concentrate. When the magnetic field strength is too small, due to insufficient gravitational force, magnetic minerals will enter aluminum-containing minerals, resulting in a decrease in the grade of aluminum concentrate. When the filling rate of the 2mm steel rod magnetic concentrating medium is too large, due to the excessive field strength, aluminum-containing minerals will be mixed into magnetic minerals, resulting in a decrease in the recovery rate of aluminum concentrate, and at the same time, the processing capacity of the magnetic separator will also be reduced. When the filling rate of the 2mm steel rod magnetic concentrating medium is too small, due to insufficient gravitational force, magnetic minerals will enter aluminum-containing minerals, resulting in a decrease in the grade of aluminum concentrate. When the number of pulsating water flushes is too large, mechanical entrainment during high-gradient magnetic separation will be reduced. Although it is beneficial to increase the alumina content of aluminum concentrate, the recovery rate of aluminum concentrate will be reduced. When the number of pulsating water flushes is too small, due to the small pulsating water, mechanical entrainment during magnetic separation will increase, resulting in a decrease in the alumina content of aluminum concentrate.

[0076] The value of the magnetic field strength can be 4000 GS, or 4500 GS, or 5000 GS, or 5500 GS, or 6000 GS, or 6500 GS, or 7000 GS, or 7500 GS, or 8000 GS.

[0077] The filling rate of the 2mm steel rod medium can be 10%, or 11%, or 12%, or 13%, or 14%, or 15%, or 16%, or 17%, or 18%, or 19%, or 20%.

[0078] The value of the number of pulsating water flushes can be 145 times / min, or 147 times / min, or 149 times / min, or 151 times / min, or 153 times / min, or 155 times / min, or 157 times / min, or 159 times / min, or 161 times / min, or 163 times / min, or 165 times / min.

[0079] In some embodiments, a smart pressure filter is used for strong dehydration. The working pressure of the smart pressure filter is 0.30 MPa to 0.60 MPa, and the feed concentration of the smart pressure filter is 35% to 50%.

[0080] In the embodiments of the present application, by controlling the types of the strong dehydration equipment, the working pressure, and the specific values of the feed concentration, aluminum concentrate and tailings with relatively low moisture content can be obtained to meet the subsequent production requirements.

[0081] When the value of the pressure filtration working pressure is too large, not only the reduction in the moisture content of the aluminum concentrate and tailings is weak, but also the energy consumption increases and the service life of the equipment decreases. When the value of the pressure filtration working pressure is too small, the moisture content of the aluminum concentrate and tailings will be too low, affecting subsequent use. When the value of the feed concentration is too large, although the moisture content of the aluminum concentrate can be reduced, the energy consumption and service life of the conveying equipment will increase. When the value of the feed concentration is too small, while the moisture content of the aluminum concentrate and tailings increases, the burden and energy consumption of the pressure filtration equipment will also increase.

[0082] The value of the working pressure can be 0.30 MPa, or 0.35 MPa, or 0.40 MPa, or 0.45 MPa, or 0.50 MPa, or 0.55 MPa, or 0.60 MPa.

[0083] The value of the feed concentration can be 35%, or 36%, or 37%, or 38%, or 39%, or 40%, or 41%, or 42%, or 43%, or 44%, or 45%, or 46%, or 47%, or 48%, or 49%, or 50%.

[0084] In some embodiments, by mass fraction, the moisture content of the aluminum concentrate ≤ 12%, and the moisture content of the tailings ≤ 20%.

[0085] In the embodiments of the present application, by controlling the specific values of the moisture content of the aluminum concentrate and tailings, it shows that the moisture content of the aluminum concentrate and tailings extracted by the method provided in the embodiments of the present application is low, which is more conducive to the subsequent alumina dissolution of the aluminum concentrate and the soil improvement of the tailings.

[0086] In some embodiments, after obtaining the aluminum concentrate, tailings, and return water, the method further includes:

[0087] The return water returns to the stirring and pulping step for recycling;

[0088] Mix the tailings with the mining waste rock crushed to a preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation; the preset particle size is 3 - 5 mm, and the predetermined ratio is tailings: crushed waste rock = 2:1 - 1:1.

[0089] In the embodiments of the present application, by controlling the specific values of the preset particle size and the predetermined ratio, soil more conducive to the soil remediation of the mining area can be obtained. When the value of the preset particle size is too large, it cannot achieve the purpose of adjusting the composition of the tailings and thus cannot be used for soil modification in the mining area. When the value of the preset particle size is too small, it not only cannot adjust the particle size composition of the tailings and allocate the mineral composition of the tailings, resulting in the inability to be used for soil modification in the mining area, but also increases additional crushing energy consumption. When the value of the predetermined ratio is too large, the mixing amount of the crushed waste rock is too low to achieve the purpose of adjusting the composition of the tailings, and thus it cannot be used for soil transformation in the mining area. When the value of the predetermined ratio is too small, the mixing amount of the crushed waste rock is too high, which not only cannot adjust the particle size composition of the tailings and allocate the mineral composition of the tailings, resulting in the inability to be used for soil modification in the mining area, but also reduces the utilization rate of the tailings.

[0090] The value of the preset particle size can be 3 mm, or 3.5 mm, or 4 mm, or 4.5 mm, or 5 mm.

[0091] The value of the predetermined ratio can be 2:1, or 1.5:1, or 1:1.

[0092] In summary, a method for the full quantification utilization of bauxite washing tailings provided by the embodiments of the present application has the following advantages:

[0093] (1) Process innovation and efficient dissociation: The stage scrubbing-stage sorting technology effectively disperses the agglomerated bauxite washing tailings through two-stage strong scrubbing combined with multi-stage screening (vibrating slag separation screen + straight screen), realizes the efficient dissociation of diaspore and gangue minerals, and solves the problem of incomplete dissociation caused by the agglomeration of bauxite washing tailings in the traditional process. At the same time, by using shaking table gravity separation (slope 0.8° - 1.5°) + centrifugal gravity separation (drum rotation speed 950 r / min - 1150 r / min) + high-gradient magnetic separation (magnetic field intensity 4000 GS - 8000 GS), aluminum minerals of different particle sizes are recovered step by step, especially for fine particle sizes (such as centrifugal gravity separation recovering particles <0.1 mm), significantly improving the recovery rate of aluminum minerals (taking both coarse and fine particles into account) and avoiding the limitations of a single separation technology.

[0094] (2) Double improvement in the quality and recovery rate of aluminum concentrate: The vibrating slag separation screen (aperture 2 mm - 5 mm) removes wood chips and large particle waste rock impurities, and the straight screen (aperture 0.1 mm - 0.2 mm) accurately separates coarse-grained aluminum-containing minerals, reducing the mixing of impurities into the aluminum concentrate. At the same time, the synergistic optimization of the stroke (10 mm - 12 mm), stroke frequency (280 - 310 times / min) of the shaking table and the drum inclination angle (4° - 8°) of the centrifuge balances the stratification speed and separation efficiency, promoting the Al of the aluminum concentrate 2 O 3The grade and recovery rate are improved simultaneously. In addition, high-gradient magnetic separation (steel bar filling rate 10% - 15%) can efficiently remove iron impurities and avoid Fe 2 O 3 polluting the aluminum concentrate and enhancing the alumina digestion efficiency.

[0095] (3) Full quantification of resource utilization and environmental benefits: Mix the tailings with crushed mining waste stones in proportion to improve the particle size composition (such as porosity optimization) and mineral balance, and prepare them into a material for soil remediation in the mining area. This not only solves the environmental risk of tailings accumulation but also reduces the remediation cost. At the same time, the dehydrated recycled water is used in the pulping step to reduce the consumption of fresh water and achieve zero discharge. In addition, through magnetic separation to remove iron + sawdust to separate slag, impurities (such as Fe, organic matter) are prevented from entering the subsequent process, reducing the pollutant residues in the tailings.

[0096] (4) Advantages of economy and applicability: Use conventional separation equipment (shaking table, centrifuge, magnetic separator), avoid high-investment high-pressure flotation or acid leaching processes, and reduce operating costs. At the same time, for the design of the plate-end tailings with Al 2 O 3 ≥35% and A / S ≤ 3, the applicable range is clear (such as high-aluminum and low-silicon tailings), and the process stability is strong.

[0097] (5) Solving industry pain points: For the caking problem caused by flocculants in the tailings pond, through strong scrubbing and dispersion pulping, the separability of minerals is restored. At the same time, the traditional gravity separation has a low recovery rate for particles < 0.074mm. This process combines centrifugal gravity separation + magnetic separation to significantly reduce the loss of fine-grained aluminum minerals.

[0098] Therefore, through the full-process design of multi-stage scrubbing - classification separation - magnetic separation to remove impurities - tailings resource utilization, this application has achieved the full-quantification goal of the trinity of efficient dissociation of bauxite washing tailings, high-value recovery of aluminum resources, and ecological utilization of tailings, combining technological advancement with economic environmental protection, and providing an innovative solution for the clean and resource utilization of similar bauxite washing tailings.

[0099] The following will further elaborate 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 the conditions recommended by the manufacturer.

[0100] Example 1

[0101] Select the bauxite washing tailings from a tailings pond in a certain place in Guangxi. By mass fraction, its main chemical components include: Al 2 O 3 : 35.41%, SiO 2: 30.22%, Fe 2 O 3 : 21.62%. The main useful mineral in this bauxite washing tailings is diaspore, and the gangue minerals are mainly chlorite, calcite and kaolinite. Iron mainly exists in the form of hematite and a small amount of siderite. The method steps for the full utilization of bauxite washing tailings are as Figure 1 shown. The specific process is as follows:

[0102] S1. Stir and pulp the bauxite washing tailings collected from the tailings pond, and then use a bucket scrubber for a first strong scrubbing to obtain a dispersed pulp.

[0103] Among them: the concentration of the first strong scrubbing is 35%, and the process of the first strong scrubbing is 3-stage scrubbing in series.

[0104] S2. Feed the dispersed pulp into a vibrating slag separator with a screen aperture of 4 mm for impurity removal to obtain the pulp to be beneficiated and wood chip impurities.

[0105] S3. Feed the pulp to be beneficiated into a straight-line screen with a screen aperture of 0.15 mm for a first screening to obtain a first aluminum-containing material and a first fine-grained material.

[0106] S4. Use a bucket scrubber to perform a second strong scrubbing on the first aluminum-containing material, and then feed it into a straight-line screen with a screen aperture of 0.15 mm for a second screening to obtain a second aluminum-containing material and a second fine-grained material.

[0107] Among them: the concentration of the second strong scrubbing is 40%, and the process of the first strong scrubbing is 2-stage scrubbing in series.

[0108] S5. Combine the first fine-grained material and the second fine-grained material and perform slime table gravity separation to obtain a third aluminum-containing material and a third fine-grained material.

[0109] Among them: the slope of the slime table is 0.9°; the stroke of the slime table is 10 mm; the stroke frequency of the slime table is 295 times / min.

[0110] S6. Use centrifugal beneficiation to perform centrifugal gravity separation on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material.

[0111] Among them: the drum speed of the centrifugal concentrator is 980 r / min; the drum inclination angle of the centrifugal concentrator is 8°.

[0112] S7. Combine the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain an aluminum concentrate pulp and a magnetic material pulp;

[0113] Among them: the high-gradient magnetic separation field strength is 5000 GS; the filling rate of 2 mm steel rod medium is 15%; the high-gradient pulsating water stroke frequency is 151 times / min.

[0114] S8. Combine the magnetic material pulp with the fourth fine-grained material to obtain tailing pulp.

[0115] S9. Use intelligent pressure filtration to strongly dehydrate the concentrated aluminum concentrate pulp and tailing pulp to obtain aluminum concentrate, tailings and recycled water, and the recycled water is returned to the stirring and pulping process for recycling.

[0116] Among them: the working pressure of the pressure filter is 0.45 MPa, and the feed concentration is 41%.

[0117] S10. Mix the tailings with the mined waste rock crushed according to the preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation.

[0118] Among them: the preset particle size is 3 mm to 5 mm, and the predetermined ratio is tailings: crushed waste rock = 2:1.

[0119] The component content of the product obtained in Example 1 is shown in Table 1:

[0120] Table 1 Component content of the product in Example 1

[0121]

[0122] Example 2

[0123] Select the bauxite washing tailings in a tailings pond in a certain place in Yunnan. In terms of mass fraction, its main chemical components include: Al 2 O 3 : 40.37%, SiO 2 : 24.22%, Fe 2 O 3 : 18.52%. The main useful mineral in this bauxite washing tailings is diaspore, and the gangue minerals are mainly calcite, kaolinite and chlorite, etc. Iron mainly occurs in the form of hematite. The method steps for the full utilization of a bauxite washing tailings are as Figure 1 shown, and the specific process is:

[0124] S1. Stir and pulp the bauxite washing tailings mined from the tailings pond, and then use a bucket scrubber for a first strong scrubbing to obtain a dispersed pulp.

[0125] Among them: the concentration of the first strong scrubbing is 30%, and the first strong scrubbing process is a series of 2-stage scrubbing.

[0126] S2. Feed the dispersed pulp into a vibrating slag separator with a screen aperture of 3 mm for impurity removal to obtain the pulp to be beneficiated and wood chip impurities.

[0127] S3. Feed the pulp to be beneficiated into a straight screen with a screen aperture of 0.12 mm for a first screening to obtain the first aluminum-containing material and the first fine-grained material.

[0128] S4. Use a bucket-wheel scrubber to perform secondary strong scrubbing on the first aluminum-containing material, and then send it into a straight-line screen with a screen aperture of 0.12 mm for secondary screening to obtain a second aluminum-containing material and a second fine-grained material.

[0129] Among them: the concentration of secondary strong scrubbing is 38%, and the process of primary strong scrubbing is a series connection of 2-stage scrubbing.

[0130] S5. Combine the first fine-grained material and the second fine-grained material and perform slime table gravity separation to obtain a third aluminum-containing material and a third fine-grained material.

[0131] Among them: the slope of the slime table is 0.8°; the stroke of the slime table is 11 mm; the stroke frequency of the slime table is 305 times / min.

[0132] S6. Use centrifugal beneficiation to perform centrifugal gravity separation on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material.

[0133] Among them: the drum rotation speed of the centrifugal concentrator is 1020 r / min; the drum inclination angle of the centrifugal concentrator is 5°.

[0134] S7. Combine the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain an aluminum concentrate pulp and a magnetic material pulp;

[0135] Among them: the high-gradient magnetic separation field strength is 4500 GS; the filling rate of 2 mm steel rod medium is 15%; the high-gradient pulsating water stroke frequency is 147 times / min.

[0136] S8. Combine the magnetic material pulp and the fourth fine-grained material to obtain a tailing pulp.

[0137] S9. Use intelligent pressure filtration to concentrate the aluminum concentrate pulp and the tailing pulp and then perform strong dehydration to obtain aluminum concentrate, tailings and recycled water, and the recycled water returns to the stirring and pulping process for recycling.

[0138] Among them: the working pressure of the pressure filter is 0.50 MPa, and the feed concentration is 39%

[0139] S10. Mix the tailings with the mining waste rock crushed according to the preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation.

[0140] Among them: the preset particle size is 3 mm - 4 mm, and the predetermined ratio is tailings: crushed waste rock = 1:1.

[0141] The component content of the product obtained in Example 2 is shown in Table 2:

[0142] Table 2 Component content of the product in Example 2

[0143]

[0144]

[0145] Example 3

[0146] Select the bauxite washing tailings in a tailings pond in a certain place in Shanxi. In terms of mass fraction, its main chemical components include: Al 2 O 3 : 37.08%, SiO 2 : 16.22%, Fe 2 O 3 : 26.52%. The main useful mineral in this bauxite washing tailings is diaspore, and the gangue minerals are mainly kaolinite and chlorite, etc. Iron mainly occurs in the form of limonite. The method steps for the full utilization of bauxite washing tailings are as Figure 1 shown, and the specific process is as follows:

[0147] S1. Stir and pulp the bauxite washing tailings mined from the tailings pond, and then use a bucket scrubber for a first strong scrubbing to obtain a dispersed pulp.

[0148] Among them: the concentration of the first strong scrubbing is 35%, and the process of the first strong scrubbing is a series connection of 3-stage scrubbing.

[0149] S2. Feed the dispersed pulp into a vibrating slag separator with a screen aperture of 3.5 mm for impurity removal to obtain the pulp to be beneficiated and wood chip impurities.

[0150] S3. Feed the pulp to be beneficiated into a straight-line screen with a screen aperture of 0.10 mm for a first screening to obtain a first aluminum-containing material and a first fine-grained material.

[0151] S4. Use a bucket scrubber to perform a second strong scrubbing on the first aluminum-containing material, and then feed it into a straight-line screen with a screen aperture of 0.10 mm for a second screening to obtain a second aluminum-containing material and a second fine-grained material.

[0152] Among them: the concentration of the second strong scrubbing is 33%, and the process of the first strong scrubbing is a series connection of 2-stage scrubbing.

[0153] S5. Combine the first fine-grained material and the second fine-grained material and perform slime table gravity separation to obtain a third aluminum-containing material and a third fine-grained material.

[0154] Among them: the slope of the slime table is 1.2°; the stroke of the slime table is 10 mm; the stroke frequency of the slime table is 285 times / min.

[0155] S6. Use centrifugal beneficiation to perform centrifugal gravity separation on the third fine-grained material to obtain a fourth aluminum-containing material and a fourth fine-grained material.

[0156] Among them: the drum rotation speed of the centrifugal concentrator is 1100 r / min; the drum inclination angle of the centrifugal concentrator is 6.5°.

[0157] S7. Combine the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain aluminum concentrate pulp and magnetic material pulp;

[0158] Among them: the high-gradient magnetic separation field strength is 6500 GS; the filling rate of 2 mm steel rod medium is 10%; the high-gradient pulsating water flushing times is 153 times / min.

[0159] S8. Combine the magnetic material pulp with the fourth fine-grained material to obtain tailings pulp.

[0160] S9. Use intelligent pressure filtration to concentrate the aluminum concentrate pulp and the tailings pulp, and then perform strong dehydration to obtain aluminum concentrate, tailings and recycled water, and the recycled water is returned to the stirring and pulping process for recycling.

[0161] Among them: the working pressure of the pressure filter is 0.55 MPa, and the feed concentration is 40%

[0162] S10. Mix the tailings with the mining waste rock crushed according to the preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation.

[0163] Among them: the preset particle size is 3 mm - 4.5 mm, and the predetermined ratio is tailings: crushed waste rock = 1.5:1.

[0164] The component content of the product obtained in Example 3 is shown in Table 3:

[0165] Table 3 Component content of the product in Example 3

[0166]

[0167] Example 4

[0168] Select the bauxite washing tailings in a tailings pond in a certain place in Henan. By mass fraction, its main chemical components include: Al 2 O 3 : 39.37%, SiO 2 : 31.09%, Fe 2 O 3 : 11.52%. The main useful mineral in this bauxite washing tailings is diaspore, and the gangue minerals are mainly kaolinite, chlorite and so on. Iron mainly exists in the form of hematite. The method steps for the full utilization of a bauxite washing tailings are as Figure 1 shown, and the specific process is:

[0169] S1. Stir and pulp the bauxite washing tailings mined from the tailings pond, and perform a strong scrubbing once with a bucket scrubber to obtain a dispersed pulp.

[0170] Among them: the concentration of the first strong scrubbing is 28%, and the process of the first strong scrubbing is a series connection of two-stage scrubbing.

[0171] S2. Feed the dispersed pulp into a vibrating slag separator with a screen aperture of 4.5 mm for impurity removal to obtain the pulp to be beneficiated and wood chip impurities.

[0172] S3. Feed the pulp to be beneficiated into a straight-line screen with a screen aperture of 0.12 mm for the first screening to obtain the first aluminum-containing material and the first fine-grained material.

[0173] S4. Use a bucket scrubber to perform secondary strong scrubbing on the first aluminum-containing material and then feed it into a straight-line screen with a screen aperture of 0.12 mm for secondary screening to obtain the second aluminum-containing material and the second fine-grained material.

[0174] Among them: the concentration of the second strong scrubbing is 30%, and the process of the first strong scrubbing is a series connection of two-stage scrubbing.

[0175] S5. Combine the first fine-grained material and the second fine-grained material and perform gravity separation on the slime table to obtain the third aluminum-containing material and the third fine-grained material.

[0176] Among them: the slope of the slime table is 1.3°; the stroke of the slime table is 10 mm; the stroke frequency of the slime table is 295 times / min.

[0177] S6. Use centrifugal beneficiation to perform centrifugal gravity separation on the third fine-grained material to obtain the fourth aluminum-containing material and the fourth fine-grained material.

[0178] Among them: the drum speed of the centrifugal beneficiator is 1000 r / min; the drum inclination angle of the centrifugal beneficiator is 5.5°.

[0179] S7. Combine the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material and perform high-gradient magnetic separation to obtain the aluminum concentrate pulp and the magnetic material pulp;

[0180] Among them: the magnetic field strength of the high-gradient magnetic separation is 7000 GS; the filling rate of the 2 mm steel rod medium is 11%; the high-gradient pulsating water stroke frequency is 165 times / min.

[0181] S8. Combine the magnetic material pulp and the fourth fine-grained material to obtain the tailing pulp.

[0182] S9. Use intelligent pressure filtration to concentrate the aluminum concentrate pulp and the tailing pulp and then perform strong dehydration to obtain aluminum concentrate, tailings and recycled water, and the recycled water is returned to the stirring and pulping process for recycling.

[0183] Among them: the working pressure of the pressure filter is 0.50 MPa, and the feeding concentration is 42%

[0184] S10. Mix the tailings with the mined waste rock crushed to a preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation.

[0185] Among them: the preset particle size is 3 mm to 4.5 mm, and the predetermined ratio is tailings: crushed waste rock = 1.5:1.

[0186] The component content of the product obtained in Example 4 is shown in Table 4:

[0187] Table 4 Component content of the product in Example 4

[0188]

[0189] Example 5

[0190] Select the bauxite washing tailings in a tailings pond in a certain place in Guizhou. By mass fraction, its main chemical components include: Al 2 O 3 : 42.15%, SiO 2 : 28.32%, Fe 2 O 3 : 15.15%. The main useful mineral in this bauxite washing tailings is diaspore, and the gangue minerals are mainly kaolinite, chlorite, etc. Iron mainly exists in the forms of hematite and limonite. The method steps for the full quantification utilization of a bauxite washing tailings are as Figure 1 shown, and the specific process is as follows:

[0191] S1. Stir and pulp the bauxite washing tailings mined from the tailings pond, and then use a bucket scrubber for a first strong scrubbing to obtain a dispersed pulp.

[0192] Among them: the concentration of the first strong scrubbing is 38%, and the process of the first strong scrubbing is 3-stage scrubbing in series.

[0193] S2. Feed the dispersed pulp into a vibrating slag separator with a screen aperture of 3 mm for impurity removal to obtain the pulp to be beneficiated and wood chip impurities.

[0194] S3. Feed the pulp to be beneficiated into a straight screen with a screen aperture of 0.10 mm for a first screening to obtain a first aluminum-containing material and a first fine-grained material.

[0195] S4. Use a bucket scrubber to perform a second strong scrubbing on the first aluminum-containing material, and then feed it into a straight screen with a screen aperture of 0.10 mm for a second screening to obtain a second aluminum-containing material and a second fine-grained material.

[0196] Among them: the concentration of the second strong scrubbing is 25%, and the process of the first strong scrubbing is 2-stage scrubbing in series.

[0197] S5. After combining the first fine-grained material and the second fine-grained material, perform slime table gravity separation to obtain the third aluminum-containing material and the third fine-grained material.

[0198] Among them: the slope of the slime table is 1.4°; the stroke of the slime table is 10 mm; the stroke frequency of the slime table is 280 times / min.

[0199] S6. Use centrifugal beneficiation to perform centrifugal gravity separation on the third fine-grained material to obtain the fourth aluminum-containing material and the fourth fine-grained material.

[0200] Among them: the drum rotation speed of the centrifugal concentrator is 950 r / min; the drum inclination angle of the centrifugal concentrator is 7.5°.

[0201] S7. After combining the second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material, perform high-gradient magnetic separation to obtain aluminum concentrate pulp and magnetic material pulp;

[0202] Among them: the high-gradient magnetic separation field intensity is 4500 GS; the filling rate of 2 mm steel rod medium is 15%; the high-gradient pulsating water stroke frequency is 145 times / min.

[0203] S8. Combine the magnetic material pulp and the fourth fine-grained material to obtain tailings pulp.

[0204] S9. Use intelligent pressure filtration to concentrate the aluminum concentrate pulp and the tailings pulp, and then perform strong dehydration to obtain aluminum concentrate, tailings and recycled water. The recycled water is returned to the stirring and pulping process for recycling.

[0205] Among them: the working pressure of the pressure filter is 0.40 MPa, and the feed concentration is 38%

[0206] S10. Mix the tailings with the mining waste rock crushed according to the preset particle size in a predetermined ratio to obtain the soil for mine area soil remediation.

[0207] Among them: the preset particle size is 3 mm - 3.5 mm, and the predetermined ratio is tailings: crushed waste rock = 1:1.

[0208] The component content of the product obtained in Example 5 is shown in Table 5:

[0209] Table 5 Component content of the product in Example 5

[0210]

[0211] Comparative Example 1

[0212] This comparative example processes the bauxite washing tailings in a certain tailings pond in Guangxi, which is the same as that in Example 1. In terms of mass fraction, its main chemical components include: Al 2 O3: 35.41%, SiO 2 : 30.22%, Fe2 O 3 : 21.62%. After pulping, it was treated by a dry treatment method for bauxite tailings provided in Chinese Patent Application CN201710228587.5, and the component contents of the obtained product are shown in Table 6:

[0213] Table 6 Component Contents of the Product of Comparative Example 1

[0214]

[0215] Comparative Example 2

[0216] In this comparative example, the washed bauxite tailings in a tailings pond in a certain place in Yunnan, which were the same as those in Example 1, were selected. In terms of mass fraction, its main chemical components included: Al 2 O 3 : 40.37%, SiO 2 : 24.22%, Fe 2 O 3 : 18.52%. It was treated by a dry treatment method for bauxite tailings provided in Chinese Patent Application CN201710228587.5, and the component contents of the obtained product are shown in Table 7:

[0217] Table 7 Component Contents of the Product of Comparative Example 2

[0218]

[0219] Comparative Example 3

[0220] In this comparative example, the washed bauxite tailings in a tailings pond in a certain place in Shanxi, which were the same as those in Example 3, were selected. In terms of mass fraction, its main chemical components included: Al 2 O 3 : 37.08%, SiO 2 : 16.22%, Fe 2 O 3 : 26.52%. It was treated by a dry treatment method for bauxite tailings provided in Chinese Patent Application CN201710228587.5, and the component contents of the obtained product are shown in Table 8:

[0221] Table 8 Component Contents of the Product of Comparative Example 3

[0222]

[0223] Comparative Example 4

[0224] In this comparative example, the washed bauxite tailings in a tailings pond in a certain place in Henan, which were the same as those in Example 4, were selected. In terms of mass fraction, its main chemical components included: Al 2 O 3: 39.37%, SiO 2 : 31.09%, Fe 2 O 3 : 11.52%. It is treated by a dry treatment method for bauxite tailings provided by Chinese Patent Application CN201710228587.5. The component contents of the obtained product are shown in Table 9:

[0225] Table 9 Component Contents of the Product of Comparative Example 4

[0226]

[0227] Comparative Example 5

[0228] In this comparative example, the washed bauxite tailings in a certain tailings pond in Guizhou, which are the same as those in Example 5, are treated. In terms of mass fraction, its main chemical components include: Al 2 O 3 : 42.15%, SiO 2 : 28.32%, Fe 2 O 3 : 15.15%. It is treated by a dry treatment method for bauxite tailings provided by Chinese Patent Application CN201710228587.5. The component contents of the obtained product are shown in Table 10:

[0229] Table 10 Component Contents of the Product of Comparative Example 5

[0230]

[0231] The iron concentrate indexes obtained by the methods for iron separation from imported high-iron bauxite digestion red mud and comprehensive utilization of tailings provided in Examples 1 to 5 and Comparative Examples 1 to 5 are statistically analyzed, and the results are shown in Table 11.

[0232] Table 11 Statistical Table of Each Product in Examples and Comparative Examples

[0233]

[0234]

[0235] As can be seen from Table 11, the aluminum concentrates obtained by the method for full-quantification utilization of washed bauxite tailings provided in Examples 1 to 5 of the present invention have an Al 2 O 3 content of ≥ 49.71% and an aluminum-silicon ratio of ≥ 7.34, and the Fe 2 O 3 content is lower than that of the washed tailings. For the aluminum concentrates obtained from the same washed tailings in Comparative Examples 1 to 5, in terms of concentrate yield, Al 2 O 3The content and the aluminum-silicon ratio (A / S) are much lower than those of the aluminum concentrate obtained in the examples. This is because the process adopted in the examples cannot fully disperse and dissociate the compacted washed tailings, resulting in serious inclusions. At the same time, the single hydrocyclone gravity separation process cannot obtain high-quality aluminum concentrate. Moreover, the tailings obtained in Examples 1-5 can be sold as soil for soil improvement in the mining area after adjusting the particle size composition and mineral composition with crushed mining waste rocks, realizing the full utilization of bauxite washed tailings. Therefore, Examples 1-5 of this application have significant advantages compared with Comparative Examples 1-5.

[0236] In addition, one or more technical solutions in the embodiments of this application at least also have the following technical effects or advantages:

[0237] (1) The method provided in the embodiments of this application adopts the technology of stage scrubbing - stage gravity separation + high-gradient magnetic separation to recover aluminum-containing minerals, solves the problems existing in the recovery of bauxite washed tailings in the tailings pond in the prior art, such as difficult dispersion and dissociation, poor quality of aluminum concentrate, low recovery rate, etc., and improves the application prospect of the technology.

[0238] (2) There are many flocculants and serious compaction in the bauxite washed tailings in the tailings pond. After simple pulping and then gravity separation, problems such as reduced alumina grade of aluminum concentrate, clogging of equipment by wood chips, and high iron impurity content will occur. The method provided in the embodiments of this application solves the problems of difficult dispersion and dissociation of bauxite washed tailings by adopting the stage scrubbing - stage gravity separation process for the washed tailings in the tailings pond, laying a foundation for obtaining aluminum concentrate with better grade and recovery rate subsequently. At the same time, the combination of four processes of linear screen screening + slime table gravity separation + centrifugal concentrator gravity separation + magnetic separation also solves the technical problems such as inability to obtain qualified aluminum concentrate by using a single gravity separation technology and serious loss of fine-grained aluminum-containing minerals.

[0239] (3) The method provided in the embodiments of this application uses crushed mining waste rocks and tailings to be mixed in proportion to improve the particle size composition and mineral composition of the tailings and reduce the moisture content of the tailings, solves the technical problems such as easy loss of tailings as a mining area repair material and not being conducive to plant growth, and enables it to be sold as soil for repairing the mining area, thus realizing the high-value utilization of tailings.

[0240] (4) The combined process of stage scrubbing + stage gravity separation + magnetic separation provided in the embodiments of this application can not only realize the full utilization of bauxite washed tailings in the tailings pond, but also provide aluminum concentrate for alumina enterprises to reduce the external dependence. At the same time, no pollutants are generated, and it has the advantages of low cost, high economic benefits, good quality of aluminum concentrate, high recovery rate, high resource utilization rate, mature and stable process, and environmental friendliness.

[0241] 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 to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for fully utilizing bauxite washing tailings, the method comprising: The bauxite tailings are stirred and slurried and strongly scrubbed once to obtain dispersed slurry; The dispersed ore pulp is subjected to impurity removal to obtain ore pulp to be separated and sawdust impurities; Screening the ore pulp to be processed once to obtain a first aluminum-containing material and a first fine-grained material; The first aluminum-containing material is subjected to secondary strong scrubbing and secondary screening to obtain a second aluminum-containing material and a second fine-grained material; The first fine-grained material and the second fine-grained material are combined and then subjected to shaking table gravity separation to obtain a third aluminum-containing material and a third fine-grained material; The third fine-grained material is subjected to centrifugal gravity separation to obtain a fourth aluminum-containing material and a fourth fine-grained material; The second aluminum-containing material, the third aluminum-containing material and the fourth aluminum-containing material are combined and then subjected to high-gradient magnetic separation to obtain aluminum concentrate slurry and magnetic material slurry; Combining the magnetic material slurry with the fourth fine-grained material to obtain tailings slurry; The aluminum concentrate slurry and the tailings slurry are concentrated and then subjected to strong dehydration to obtain aluminum concentrate, tailings and return water respectively.

2. The method according to claim 1, characterized in that Measured by mass fraction, the chemical composition of the bauxite washed tailings satisfies the following requirements: Al2O3 content ≥ 35.00%, Fe2O3 content ≤ 30.00%, A / S ≤ 3, more than 85% by mass of the aluminum minerals in the bauxite washed tailings exist in the form of diaspore, and the bauxite washed tailings are deposited in a compacted state in the tailings pond.

3. The method according to claim 1, characterized in that The first strong scrubbing and the second strong scrubbing both use a bucket scrubbing machine; The series scrubbing process of the first strong scrubbing and the second strong scrubbing is 2 to 3 stages; The slurry concentration of the first strong scrubbing and the second strong scrubbing is 20-40%.

4. The method according to claim 1, characterized in that The impurity removal uses a vibrating slag screen, and the mesh size of the vibrating slag screen is 5mm to 2mm; The primary screening and the secondary screening both use a linear screen, and the mesh size of the linear screen is 0.1 mm to 0.2 mm.

5. The method according to claim 1, characterized in that The shaking table reselection includes the following parameters: a slope of 0.8° to 1.5°, a stroke of 10 mm to 12 mm, and a stroke frequency of 280 times / min to 310 times / min.

6. The method according to claim 1, characterized in that The centrifugal gravity separation uses a centrifugal concentrator, the drum speed of the centrifugal concentrator is 950 rpm to 1150 rpm, and the drum inclination angle of the centrifugal concentrator is 4° to 8°.

7. The method according to claim 1, characterized in that The field strength of the high gradient magnetic separation is 4000GS-8000GS, the magnetic separation medium of the high gradient magnetic separation is a 2mm steel rod with a filling rate of 10%-15%, and the pulsating water flushing frequency of the high gradient magnetic separation is 145 times / min-165 times / min.

8. The method according to claim 1, characterized in that The strong dehydration uses an intelligent pressure filter, the working pressure of the intelligent pressure filter is 0.30MPa-0.60MPa, and the feed concentration of the intelligent pressure filter is 35%-50%.

9. The method according to claim 1, characterized in that: Calculated by mass fraction, the moisture content of the aluminum concentrate is ≤12%, and the moisture content of the tailings is ≤20%.

10. The method according to claim 1, characterized in that After obtaining the aluminum concentrate, tailings and backwater, the method further comprises: The return water is returned to the stirring and slurrying step for recycling; The tailings are mixed with mining waste rock crushed to a preset particle size in a predetermined ratio to obtain soil for soil restoration of mining areas; the preset particle size is 3 mm to 5 mm, and the predetermined ratio is 2:1 to 1:1 for tailings: crushed waste rock.

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