CN116832957A - Mineral separation method of lepidolite ore - Google Patents

Abstract

The invention relates to a method for beneficiating lepidolite ore, which includes the following steps: Step S1, crush the ore to obtain grinding materials; Step S2, carry out grinding and classification operations on the grinding materials; Step S3, sieve the result obtained in Step S2 The material is subjected to magnetic separation operation to obtain iron concentrate and magnetic separation tailings; step S4, the magnetic separation tailings are subjected to cloth slide and shaking table gravity separation operations to obtain tantalum niobium tin concentrate, gravity separation tailings, and shaking table middlings. ; Step S5: After the gravity separation tailings are subjected to a desliming cyclone operation, ultra-fine feldspar and cyclone sand are obtained; Step S6: The cyclone sand is fed into the flotation operation to obtain lepidolite concentrate and Flotation tailings; Step S7, perform high-gradient magnetic separation on the flotation tailings to obtain feldspar and high-gradient magnetic separation concentrate; Step S8, mix the high-gradient magnetic separation concentrate with the shaker middlings, and return to step S2 . The recovery rate and grade of the lepidolite concentrate of the present invention can reach 73% and above 2.6%, no tailings are generated, and the comprehensive recycling value is high.

Description

A kind of mineral processing method for lepidolite ore

Technical field

The invention relates to a method for beneficiating lepidolite ore and belongs to the technical field of comprehensive utilization of minerals.

Background technique

With the rapid development of the battery industry, new energy vehicles, and electronic communications industries, "lithium" has become the most popular metal due to its excellent properties. Salt lake lithium extraction and ore lithium extraction technologies are two common methods to obtain lithium metal. The lithium-containing minerals with mining value in China are mainly spodumene (LiAl[Si ₂ O ₆ ], Li ₂ O content is 8.04%) and lepidolite (KLi _1.5 Al _1.5 (AlSi ₃ O ₁₀ ), Li ₂ O content is 8.04%). 1.23% ~ 5.90%), among which lepidolite ore is concentrated in Yichun, Jiangxi. In addition to lithium oxide, lepidolite ore is usually accompanied by a variety of valuable metal elements, such as tantalum, niobium, tin, and iron. At the same time, there are often a large number of gangue minerals, such as feldspar and quartz, in lepidolite ores. Comprehensive recovery of the above-mentioned valuable elements and gangue minerals to achieve tailing-free mineralization production in the dressing plant can create more economic value for the enterprise and is also beneficial to ecological and environmental protection.

Chinese patent application CN115999780A discloses a magnetic flotation and lithium extraction method for iron lithium mica ore, using the process flow of "high gradient strong magnetic separation pre-enrichment - flotation recovery - flotation tailings return to magnetic separation operation" for iron and lithium extraction. For the separation and recovery of mica, the magnetic separation operation uses a high gradient magnetic separator to recover lithium mica through one or more stages of strong magnetic separation and initially separate it from muscovite and other gangue; the magnetic products obtained from the magnetic separation operation are combined and floated Select, cooperate with the high-efficiency lepidolite flotation collector LYP to obtain high-quality lepidolite concentrate; the flotation tailings are returned to the high-gradient magnetic separation operation, and finally achieve efficient separation of lepidolite. However, the process shown in this method is only for enriching lepidolite and does not consider the recovery of other useful components; in addition, lepidolite ore is magnetic and can be enriched with a strong magnetic separator. Chinese patent application CN115739380A discloses a lithium ore beneficiation method, which includes the following steps: 1) crushing; 2) classification. Add the ore obtained in step 1) to a screen for classification to obtain coarse-grained ore and fine-grained ore; 3) remove Tantalum and niobium; 4) Ball milling Add the light material obtained in step 3) to the ball mill for wet ball milling; 5) Iron removal; 6) Desliming; 7) Pre-flotation; 8) Lepidolite selection; 9) Rough sweep selection Spodumene; 10) Selected spodumene. This method first deslimes and removes iron and then carries out flotation and classification. It can recover molybdenum niobium and lepidolite finished products. It is especially suitable for beneficiation of lithium ore rich in lithium fluorite and lithium tantalum niobium. However, it cannot completely Achieve tailings-free production.

There is a waste of resources and unsatisfactory economic indicators in lithium ore dressing plants. This is usually due to unreasonable formulation of process flow and unreasonable equipment selection during design. Lepidolite ore often has complex embedded characteristics, and it is difficult to recover all useful mineral components by relying on a single sorting technology. At the same time, lepidolite has similar physical and chemical properties to silicate minerals such as feldspar, so it is easy to muddy during the grinding process, worsening the separation. No effect. In response to these phenomena, how to formulate a suitable mineral processing process and select efficient mineral processing equipment to fully recover the valuable components in the ore and achieve tailings-free production of lepidolite ore is an urgent problem that needs to be solved.

Contents of the invention

In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a lepidolite ore beneficiation method to fully recover the valuable components in the ore and realize tailings-free production of lepidolite ore.

In order to solve the above technical problems, the technical solutions of the present invention are as follows:

Step S1: Crush the ore to obtain grinding materials;

Step S2: Grinding and classifying the input materials;

Step S3: Perform magnetic separation on the undersize obtained in step S2 to obtain iron concentrate and magnetic separation tailings;

Step S4, subject the magnetic separation tailings to multiple slip operations and multiple shaking table gravity separation operations to obtain tantalum-niobium-tin concentrate, gravity separation tailings, and shaking table middlings;

Step S5: Perform multi-stage desliming cyclone operation on the gravity separation tailings to obtain ultra-fine feldspar and cyclone sand;

Step S6: Feed the cyclone sand into the flotation operation to obtain lepidolite concentrate and flotation tailings;

Step S7: Perform high-gradient magnetic separation on the flotation tailings to obtain feldspar and high-gradient magnetic separation concentrate;

Step S8: Mix the high-gradient magnetic separation concentrate with the shaker medium ore obtained in step S4, and return to step S2.

The present invention adopts the process of weak magnetic separation-gravity separation-flotation-strong magnetic separation to select lepidolite ore. Controlling the classification particle size during the grinding and classification stage can effectively reduce the impact of particle size on subsequent gravity separation operations; first, the iron concentrate is selected through a weak magnetic operation, and then the high specific gravity mineral tantalum is selected using cloth slide operation and shaking table gravity separation operation. Niobium tin; feldspar is easily ground in lepidolite ore, and can be separated from flake lepidolite through cyclone classification, thereby obtaining ultra-fine-grained feldspar concentrate; lepidolite can be separated through flotation and feldspar; the flotation tailings are re-classified and gravity-selected and returned to the upper-level process to achieve tailings-free and comprehensive utilization of ores.

Further, in step S1, a three-stage one-closed-circuit crushing and screening process is used to crush the ore to a particle size less than 12 mm. After the ore is coarsely crushed, medium crushed, and finely crushed and screened, it reaches the fineness requirement for entering the mill. "Three stages" means that the ore needs to be crushed three times, and "one closed circuit" means that the final stage of fine crusher and screen form a closed circuit operation to control the particle size of the crushed products. In this way, the grinding capacity can be improved and the grinding materials with the required particle size can be easily obtained. Further, in step S2, the grinding and classification operation adopts a double closed-circuit process of ball mill, cyclone, and high-frequency fine screen. After the material is ball milled, it enters the cyclone, and the overflow of the cyclone is fed to the high-frequency fine screen. The materials and cyclone grit are returned to the ball mill. The product particle size under the high-frequency screen is less than 0.15mm, accounting for 60%-80%. The high-frequency fine screen is a ten-stack vibrating screen, and the screening efficiency can reach 88%-90%. The grinding and classification operation is to crush the ore to the grinding size and then feed it into the grinding mill for further crushing. The grinding mill usually forms a closed-circuit operation with the hydrocyclone, that is, the materials after grinding enter the hydrocyclone for classification. The final sand settling (larger particle size) is returned to the mill to continue grinding, and the overflow product (usually measured with -0.15mm, -0.074mm, -0.037mm particle size content) enters the next step. The hydrocyclone is prone to "coarse" phenomenon during the production process, resulting in insufficient dissociation of mineral monomers in the grinding products, which affects subsequent sorting operations. Therefore, a high-frequency fine screening operation and a ball mill are added after the cyclone. Closed-circuit operation, strictly control overflow product particle size.

Further, in step S3, the magnetic field intensity of the magnetic separation operation is 0.6-0.85T. Magnetic separation is based on the magnetic differences of different components in the material to be separated, and uses different types of magnetic separators to separate different magnetic components in the material. In this way, the iron concentrate is selected through a period of weak magnetic operation to achieve efficient sorting of iron concentrate. At the same time, it can improve the influence of unavoidable ion Fe ³⁺ on lepidolite flotation, which is beneficial to improving the quality of lepidolite concentrate.

Further, in step S4, two cloth-sliding operations and two shaker re-selection operations are used, and both use one stage of rough selection and one stage of sweeping selection. The tailings from the rough separation of the Buliu are fed into the Sweeping operation of the Buliu. The roughing concentrates from the Buliu and the sweeping concentrates are mixed and then enter the shaking table operation. The roughing ore from the shaking table is fed into the sweeping operation of the shaking table. The roughing and sweeping operation of the shaking table is carried out. The scavenging concentrate is mixed to form tantalum-niobium-tin concentrate; the Buliu scavenging tailings, shaking table roughing and scavenging tailings are used as gravity separation tailings for subsequent desliming cyclone operations. In this way, after two stages of cloth slide operation and two stages of shaking table operation, the tantalum niobium tin concentrate in the raw ore can basically be recovered.

Clothing operation is a gravity separation process that uses the density difference between minerals to separate minerals with different specific gravity. It is suitable for the separation of fine-grained minerals. Feed the material into the cloth slide equipment. The cloth slide is arranged in a ladder. During the sorting process, the light particles are taken away by the water flow, and the heavy particles are adsorbed on the blanket of the cloth slide. After a period of time, use a high-pressure water gun to clean the blanket. Complete A cycle operation. In the present invention, the whole process of the cloth and sliding equipment is realized with automatic control. Shaking table operation is also a gravity separation process. It uses the density and particle size differences between minerals to separate minerals with different specific gravity using shaking table equipment. It is suitable for fine-grained mineral sorting. Specifically, the material flows into the shaking table through the feeding trough, and is loosened and stratified under the action of water flow and bed surface vibration. After stratification, the upper light minerals move downward along the lateral slope of the bed surface and become tailings. The heavy minerals located in the lower layer are driven by the asymmetric reciprocating motion of the bed surface and move longitudinally to the opposite side of the transmission end to become concentrate. Ore particles are divided into fan-shaped zones on the shaking table due to differences in density and particle size.

Further, in step S5, a 2-stage desliming cyclone operation is performed. The 2-stage cyclone forms a closed-circuit operation. The overflow of the first-stage cyclone is fed into the second-stage cyclone, and the second-stage cyclone overflows. Ultra-fine feldspar is obtained by flowing through the two stages of dehydration operations of the inclined plate thickener and the filter press. The sand settled in the second stage cyclone returns to the first stage cyclone, and the sand settled in the first stage cyclone is followed by flotation operation. By pre-separating ultra-fine feldspar, it not only effectively reduces the cost of flotation reagents, but also reduces the specifications of equipment such as flotation machines and stirring tanks, saving water resources.

The ultra-fine feldspar is a feldspar powder product with a particle size of 10 μm or 15 μm or 20 μm, which is mainly used to produce fillers for paints, plastics, rubber and other products.

Further, in step S6, the flotation operation is carried out in an environment with a pH of 7-10, the roughing slurry mass concentration is 25%-35%, and the flotation agent contains a collector, an activator and a dispersant, wherein the collector The dosage of agent, activator and dispersant in the rough selection section is 200-400g/t raw ore, 100-300g/t raw ore and 150-300g/t raw ore respectively. Further, the collector contains at least one of dodecylamine, oleic acid, oxidized paraffin soap, and tributyl phosphate. The collector can selectively adsorb on the surface of lepidolite mineral, leading to the formation of mineralized foam and prompting it to be scraped out as a foam product.

Further, the activator is an aluminum chloride solution, which can selectively activate lepidolite, promote the adsorption of the collector on the mineral surface, and expand the difference in floatability between it and the feldspar surface.

Furthermore, the dispersant is sodium hexametaphosphate solution. The dispersant can be adsorbed on the surface of fine mud minerals, change the electrical properties of the mineral surface, and inhibit the electrostatic adsorption between the fine mud and minerals, thereby reducing the amount of entrained floating matter.

In some embodiments, in step S6, the flotation operation includes the following steps: feeding the rough selection foam into the first selection operation, feeding the first selection foam into the second selection operation, and obtaining lepidolite concentrate after dehydration of the second selection foam. Products, the tailings from the two stages of beneficiation operations are returned to the upper-level operation in sequence, the flotation tailings are fed into the first sweeping operation, the tailings from the first sweeping operation are fed into the second sweeping operation, and the foam obtained from the two stages of sweeping is returned to the superior operation in sequence; sweeping operation The second tailings will be selected for subsequent high-gradient magnetic separation operations. In this way, the recovery effect of lepidolite concentrate is improved and efficient recovery of lepidolite concentrate is achieved. Further, in step S7, the magnetic field intensity of the high gradient magnetic separation operation is 1-2T. To facilitate full recovery of feldspar products. Ceramic grade feldspar products are obtained after filtration of high gradient magnetic separation tailings. High gradient magnetic separator is used for high gradient magnetic separation operation. High gradient magnetic separator is a strong magnetic separator used for the separation of weak magnetic minerals. It can separate extremely weak magnetic fine particles that are difficult to be separated by ordinary magnetic separators. material, lower the lower limit of sorting particle size.

Further, in step S4, the flow direction of the shaker medium ore is consistent with that of the high gradient magnetic separation concentrate in step S8. In some embodiments, in step S8, the high gradient magnetic separation concentrate is the same as the flow direction of the shaker medium ore obtained in step S4. Mix, carry out cyclone classification operation, graded sand settling is fed to step S2, the graded overflow is concentrated and the slurry mass concentration is 10%-20%, graded overflow is used for cloth flow operation, and cloth flow concentrate is fed to step S4, The cloth tailings are fed into step S5. The cloth-sliding operation adopts one roughing and one sweep. The tailings from the rough selection in the cloth-sliding flow flow into the cloth-sliding and sweeping process, and the tailings from the cloth-sliding and sweeping process are fed into the inclined plate thickener in step S5 to obtain ultra-fine feldspar products; the cloth-sliding and sweeping concentrates The roughing concentrate of the cloth slide is fed into the shaking table roughing operation in step S4. In this way, not only can tantalum, niobium and tin metals be fully recovered, but the purpose of tailings-free production can also be achieved.

Compared with the prior art, the beneficial effects of the present invention are as follows:

(1) The present invention can obtain qualified iron concentrate, tantalum niobium tin concentrate, ultra-fine feldspar concentrate, lepidolite concentrate and ceramic grade feldspar concentrate, and the recovery rate and grade of the main recovered mineral lepidolite concentrate It can reach more than 73% and 2.6%, no tailings are generated, and the comprehensive recycling value is high.

(2) The present invention strictly controls the grinding particle size through cyclones and high-frequency fine screens, and pre-separates iron concentrate, tantalum-niobium-tin concentrate and ultra-fine feldspar through classification and gravity separation. On the one hand, it can effectively reduce flotation It can reduce the cost of chemicals and reduce the specifications of equipment such as flotation machines and stirring tanks. On the other hand, it can improve the influence of unavoidable ion Fe ³⁺ on lepidolite flotation, which is beneficial to improving the quality of lepidolite concentrate.

(3) The present invention adopts cloth slide and shaking table gravity separation, which has strong adaptability to fine-grained minerals and high separation efficiency.

(4) The present invention performs a stage of high-gradient magnetic separation on the scavenging tailings to further recover the weakly magnetic iron and tantalum niobium while ensuring the quality of the feldspar.

(5) The mineral processing return water utilization rate is high, water resources are saved, and the economic and environmental benefits are obvious.

Description of the drawings

Figure 1 is a process flow diagram in Embodiment 1 of the present invention.

Detailed ways

The present invention will be described in detail below with reference to examples. It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

Example 1

In this example, the raw ore is a lepidolite ore in the Yichun area of Jiangxi Province, with a Li ₂ O content of 0.42%. Other chemical components mainly include SiO ₂ content of 68.52%, Al ₂ O ₃ content of 18.73%, K ₂ O content of 3.83%, and Na ₂ O The content is 3.6%, the MgO content is 0.18%, and the Fe ₂ O ₃ content is 0.64%. Li ₂ O in the raw ore mainly occurs in lepidolite. The main minerals in the ore are potassium feldspar, nanofeldspar, quartz, mica, calcite, and a small amount of pyrite, fluorite, monazite, hematite, and zircon. , Topaz, etc.

A method for beneficiating lepidolite ore, the process flow of which is shown in Figure 1, which specifically includes the following steps:

Step S1: Use a three-stage one-closed-circuit crushing and screening process to crush the ore to obtain grinding materials with a predetermined fineness.

Step S2: Grind and classify the ore under the sieve obtained in Step S1. The grinding fineness is -0.15mm accounting for 70%.

Step S3: Perform weak magnetic separation on the undersized material obtained in Step S2. The magnetic field strength is 0.8T. The magnetic separation concentrate is dehydrated in two stages, the inclined plate thickener and the belt filter, to obtain an iron concentrate product.

Step S4: The weak magnetic tailings obtained in step S3 are subjected to 2 cloth slide operations and 2 shaking table gravity selection operations, and the cloth slide roughing tailings are fed into the cloth slide sweeping operation, and the cloth slide roughing and sweeping fine selection operations are carried out. After the ore is mixed, it enters the shaking table operation, and the shaker roughing ore is fed into the shaking table sweeping operation. The shaking table roughing and sweeping concentrates are mixed to form tantalum niobium tin concentrate.

Step S5: Mix the cloth from step S4 with the shaker tailings, and perform a two-stage desliming cyclone closed-circuit operation. The overflow product obtained is ultrafine feldspar.

Step S6: Carry out flotation operation using the cyclone sand sedimentation obtained in Step S5, in which the mass concentration of roughing slurry is 30%, the pH value of slurry is 8, and the flotation reagents are collectors, activators and dispersants, and their dosages are respectively For 350g/t raw ore, 100g/t raw ore, 250g/t raw ore, a closed-circuit process of one coarse, two fines and two sweeps is adopted. The coarse foam is fed into the first selection operation, the foam from the first selection is fed into the second selection operation, and the fine foam is fed into the second selection operation. Lepidolite concentrate product is obtained after the second selection foam is dehydrated; the tailings of the two stages of selection operation are returned to the upper level operation in sequence, and the rough selection tailings are fed into the first sweeping operation, and the tailings of the first sweeping operation are fed into the second sweeping operation. The bubbles obtained by scanning are returned to the upper level operation in sequence.

Step S7: The above-mentioned scavenging tailings are then subjected to a high-gradient magnetic separation operation with a magnetic field strength of 1.5T. The magnetic separation tailings are ceramic-grade feldspar products.

Step S8: Mix the above-mentioned high gradient magnetic separation concentrate with the shaker medium ore obtained in step S4, perform a cyclone classification operation, and feed the classified sand into the cyclone classification and regrinding operation of step S2; classify the overflow mass concentration It is 15%, and then enters the cloth-liu gravity selection operation after concentration; the cloth-liu gravity selection adopts one coarse and one sweep. The ore is fed into the shaking table roughing operation of step S4.

In step S6, the collector contains dodecylamine, oleic acid, and oxidized paraffin soap. The ratio of the mass of dodecylamine to the total mass of oleic acid and oxidized paraffin soap is 1:4. The configuration of the collector The process is to first dissolve dodecamine in tributyl phosphate, add oleic acid and oxidized paraffin soap, then add sodium hydroxide solution and alcohol solution and heat and stir.

In step S6, the activator is aluminum chloride solution, and the dispersant is sodium hexametaphosphate solution.

Under the above-mentioned process flow, the ore can finally be separated into lepidolite concentrate containing 2.6% Li ₂ O and a recovery rate of 73%, as well as qualified iron ore concentrate (TFe=55%), tantalum-niobium-tin concentrate ( Ta ₂ O ₅ recovery rate 34.2%, Nb ₂ O ₅ recovery rate 22.5%, tin recovery rate 33.8%), ultra-fine feldspar (yield 18%), ceramic grade feldspar products (yield 69%), fully recovered The valuable mineral components of the raw ore are removed, and the purpose of tailing-free production of the mineral processing plant is achieved.

Example 2

The difference between this embodiment and Embodiment 1 is that in step S4, a set of cyclones and high-frequency fine screen classification operations are added after the cloth slide is swept to further recover the tantalum and niobium minerals in the sieve supernatant, The recovery rate of tantalum and niobium is increased, and the whiteness of feldspar can be increased, allowing it to be sold as a high-whiteness feldspar product.

Example 3

The difference between this embodiment and Example 1 is that in step S6, the mass concentration of the roughing slurry is 35%, the pH value of the slurry is 10, and the amounts of collector, activator and dispersant in the roughing section are 250g/t raw ore respectively. , 200g/t raw ore, 200g/t raw ore can obtain lepidolite concentrate containing Li ₂ O2.3% and a recovery rate of 75%, while the yield of ceramic grade feldspar is slightly reduced.

Example 4

The difference between this embodiment and Example 1 is that in step S6, the mass concentration of the roughing slurry is 25%, the pH value of the slurry is 7, and the amounts of collector, activator and dispersant in the roughing section are 300g/t raw ore respectively. , 100g/t raw ore, 300g/t raw ore, lepidolite concentrate containing Li ₂ O2.7% and recovery rate of 70% can be obtained, and the yield of ceramic grade feldspar is slightly increased.

Example 5

The difference between this embodiment and Embodiment 1 is that the classification and gravity separation operations in step S8 are cancelled, and the high gradient magnetic separation tailings and the shaker middlings obtained in step S4 are directly fed to the cyclone in step S2 for classification and regrinding. During the operation, the recovery rate of tantalum, niobium and tin decreased slightly, the yield of ultra-slender feldspar increased, and the recovery rate of Li ₂ O of lepidolite concentrate decreased by 2%.

Comparative example 1

The difference from Example 1 is that deleting the high-frequency fine screening operation in step S2 will cause the phenomenon of coarsening. Minerals such as lepidolite cannot be fully dissociated into monomers, and the grade and recovery rate of flotation lepidolite concentrate will decrease. , 2.1% and 65% respectively, while the iron concentrate grade decreased and the feldspar concentrate yield increased slightly.

Comparative example 2

The difference from Example 1 is that in step S6, no activator is added, the lepidolite concentrate grade (2.6%) remains basically unchanged, while the recovery rate drops significantly to 64%, and the SiO ₂ content in the feldspar increases. , the quality deteriorates.

The content illustrated in the above embodiments should be understood that these embodiments are only used to illustrate the present invention more clearly, and are not used to limit the scope of the present invention. After reading the present invention, those skilled in the art will be familiar with various equivalent forms of the present invention. All modifications fall within the scope defined by the appended claims of this application.

Claims (10)

1. The mineral separation method of the lepidolite ore is characterized by comprising the following steps of:

s1, crushing ores to obtain grinding materials;

s2, carrying out ore grinding classification operation on the materials to be ground;

s3, carrying out magnetic separation operation on the undersize obtained in the step S2 to obtain iron concentrate and magnetic separation tailings;

s4, carrying out multiple slip distribution operations and multiple shaking table gravity separation operations on the magnetic separation tailings to obtain tantalum-niobium-tin concentrate, gravity separation tailings and shaking table middlings;

s5, performing multistage desliming cyclone operation on the gravity tailings to obtain superfine feldspar and cyclone sand setting;

s6, feeding the cyclone sand setting into flotation operation to obtain lepidolite concentrate and flotation tailings;

s7, performing high-gradient magnetic separation operation on the flotation tailings to obtain feldspar and high-gradient magnetic separation concentrate;

and S8, mixing the high-gradient magnetic concentrate with the middlings of the cradle obtained in the step S4, and returning to the step S2.

2. The beneficiation process according to claim 1, wherein in step S1, the ore is crushed to a particle size of less than 12mm using a three-stage one-pass closed-circuit crushing and screening process.

3. The beneficiation method according to claim 1, wherein in the step S2, materials enter a cyclone after ball milling, the cyclone overflows and is fed into a high-frequency fine screen, and oversize materials and cyclone sand setting are returned to ball milling together; the granularity of the product under the high-frequency sieve is less than 0.15mm and accounts for 60-80 percent.

4. The beneficiation process according to claim 1, wherein in step S3, the magnetic field strength of the magnetic separation operation is 0.6-0.85T.

5. The beneficiation method according to claim 1, wherein in step S4, 2 operations of distributing and reselecting the cradle are adopted, and a roughing process and a scavenging process are adopted.

6. The beneficiation method according to claim 1, wherein in the step S5, 2 stages of desliming cyclones are closed-circuit operation, the overflow of the first stage of cyclones is fed into the second stage of cyclones, and the overflow of the second stage of cyclones is subjected to two stages of dewatering operation through an inclined plate thickener and a filter press.

7. The beneficiation method according to claim 1, wherein in the step S6, flotation operation is performed under the environment of pH 7-10, the mass concentration of rougher pulp is 25% -35%, and the flotation reagent comprises a collector, an activator and a dispersing agent, wherein the rougher stage of the collector, the activator and the dispersing agent is respectively used for 200-400g/t of raw ore, 100-300g/t of raw ore and 150-300g/t of raw ore.

8. The beneficiation process according to claim 7, wherein the activator is an aluminum chloride solution; the dispersing agent is sodium hexametaphosphate solution; the collector contains at least one of dodecyl amine, oleic acid, oxidized paraffin soap and tributyl phosphate.

9. The beneficiation method according to claim 1, wherein in step S7, the magnetic field strength of the high gradient magnetic separation operation is 1-2T.

10. The beneficiation method according to any one of claims 1 to 9, wherein in step S8, high gradient magnetic concentrate is mixed with the shaking middlings obtained in step S4, cyclone classification operation is performed, classified sand setting is performed in step S2, the mass concentration of the concentrated ore pulp after classification overflow is 10% -20%, classification overflow is performed in a distributing operation, distributing concentrate is performed in step S4, and distributing tailings are performed in step S5.