Full-particle-size flotation process method for improving lepidolite recovery rate through fine silt pretreatment

Abstract

The invention relates to a full-particle-size flotation process method for improving the recovery rate of lepidolite through fine silt pretreatment. The full-particle-size flotation process method comprises the following steps that crushed lepidolite raw ore is subjected to ore grinding operation; conveying the ore grinding product to a first hydrocyclone; feeding an underflow product of the first hydrocyclone into a five-lamination high-frequency vibrating screen, returning an oversize product to a ball mill for regrinding, and removing iron from an undersize product; feeding the non-magnetic material subjected to iron removal into a spreading chute; carrying out shaking table roughing and re-selection on the distributed ore concentrate; feeding the cloth sliding tailings and the shaking table roughing and checking tailings into a first-section cyclone; overflow of the first-section cyclone is fed into a first deep-cone thickener; the deep cone underflow is added into a fine silt pretreatment tank, a dispersing agent is added into the fine silt pretreatment tank, uniform stirring and pretreatment are performed, and pretreated fine silt is obtained; and the first-section cyclone underflow and pretreated fine silt mixed ore pulp is added into a flotation stirring barrel, a matched collecting agent is added, and flotation operation is carried out. The method can improve the recovery rate of lepidolite, synchronously improve the whiteness of feldspar and the like.

Description

A full-size flotation process for improving lepidolite recovery through fine mud pretreatment Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a full-size flotation process method for improving the recovery rate of lepidolite through fine mud pretreatment. Background Technology

[0002] Lepidolite is a naturally occurring mica mineral. Lepidolite deposits found in the Earth's crust often exist as associated minerals with other rare metals. Lithium extraction from lepidolite concentrate is one of the main sources of lithium. With the development of new energy vehicles, electronic products, and energy storage systems, the demand for lithium in lithium-ion batteries for electronic devices and electric vehicles is enormous. Depending on the composition of lepidolite ore, physical beneficiation and enrichment methods can be used, including magnetic separation, flotation, and gravity separation. For beneficiation plants, flotation is an extremely important method for separating lepidolite.

[0003] In existing flotation technologies, most fine mud particles are directly removed by hydrocyclones without being recovered. A small portion of the remaining fine mud enters the conventional flotation system. Due to the agglomeration and poor floatability of the fine mud, it is difficult to collect, resulting in a significant loss of fine mud lepidolite and extremely low resource utilization. This is the core pain point of the low recovery rate of existing processes. Existing flotation technologies suffer from low lepidolite recovery rates due to the lack of pretreatment of fine mud and the direct removal without recovery of fine mud. In existing flotation processes, untreated fine mud easily agglomerates and covers the surface of coarse lepidolite particles, hindering effective contact between the collector and the lepidolite. This not only prevents the recovery of fine mud lepidolite but also reduces the collection efficiency of coarse lepidolite, causing large fluctuations in flotation indicators and unstable recovery rates. The agglomeration and covering of fine mud lead to low efficiency and large fluctuations in recovery rates in conventional flotation.

[0004] In existing technologies, after the flotation of lepidolite, fine mud impurities and small gangue particles easily adhere to the surface of feldspar in the tailings, resulting in low feldspar whiteness, which cannot meet the requirements of industrial applications and can only be discarded as waste rock, causing a waste of feldspar resources. Existing technologies for lepidolite flotation suffer from problems such as surface pollution, low whiteness, and low added value of feldspar. Summary of the Invention

[0005] In response to the problems of low lepidolite recovery rate and poor recovery effect in the conventional desliming flotation process of lepidolite beneficiation plants mentioned above, the applicant provides a full-size flotation process method for improving lepidolite recovery rate through fine mud pretreatment, which can achieve technical effects such as significantly improving lepidolite recovery rate and simultaneously improving feldspar whiteness after flotation.

[0006] The technical solution adopted in this invention is as follows: A full-size flotation process method for improving the recovery rate of lepidolite through fine mud pretreatment, specifically including the following steps: Step S1, the crushed lepidolite ore is fed into a ball mill for grinding; Step S2, the grinding product obtained in Step S1 is fed to a first hydrocyclone for classification, and the first hydrocyclone obtains underflow product and overflow product after classification; Step S3, the underflow product of the first hydrocyclone obtained in Step S2 is fed into a five-layer high-frequency vibrating screen for classification, obtaining underflow product and overflow product respectively, and the overflow product of the high-frequency vibrating screen is returned to the ball mill for re-grinding, forming a classification closed circuit with the ball mill; the underflow product of the high-frequency vibrating screen and the overflow product of the first hydrocyclone in Step S2 are combined and fed into a weak magnetic separator for iron removal treatment, obtaining non-magnetic material and magnetic material; Step S4, the non-magnetic material after iron removal in Step S3 is fed into a cloth sluice, and the magnetic material is used as iron concentrate product. Bulu concentrate undergoes roughing and re-concentration on shaking tables to obtain tantalum-niobium-tin concentrate products. The middlings from the shaking tables are fed into the pump pool of the second hydrocyclone, while the Bulu tailings proceed to the next process. In step S5, the Bulu tailings obtained in step S4, along with the roughing and re-concentration tailings from the shaking tables, are fed into a first-stage hydrocyclone to obtain underflow and overflow. In step S6, the overflow from the first-stage hydrocyclone obtained in step S5 is fed into the first deep cone thickener for sedimentation and thickening. The deep cone overflow is returned to the circulating water tank as reclaimed water; in step S7, the deep cone underflow obtained in step S6 is added to the fine mud pretreatment tank, and a dispersant is added to the fine mud pretreatment tank for uniform pretreatment to obtain pretreated fine mud; in step S8, the mixed slurry of the hydrocyclone underflow obtained in step S5 and the pretreated fine mud obtained in step S7 is added to the flotation mixing tank, and a compatible collector is added to the flotation mixing tank. After uniform mixing, flotation is performed for roughing to obtain... The obtained foam product is the lepidolite roughing concentrate product, and the other part is the roughing tailings product; in step S9, the roughing concentrate product from step S8 is fed into the first cleaning operation, and the obtained foam product is the first cleaning concentrate product, and the other part is the first cleaning middlings product; the first cleaning concentrate product is fed into the second cleaning operation, and the obtained foam product is the lepidolite second cleaning concentrate product. The lepidolite second cleaning concentrate product is dewatered by a belt filter to obtain lepidolite concentrate product, and the other part is the second cleaning middlings product; the second cleaning middlings product is combined with the roughing concentrate product from step S8 for the first cleaning operation to form a closed-loop operation; in step S10, the roughing tailings product from step S8 is fed into the first scavenging operation, and the obtained foam product is the first scavenging middlings product, and the other part is the first scavenging tailings product; the obtained first scavenging middlings product and the first cleaning middlings product obtained in step S9 are combined and fed back into the roughing operation to form a large closed-loop flotation system.

[0007] As a further improvement to the above technical solution: in step S1, the lithium mica ore in the grinding product has a particle size of ≤5mm and accounts for more than 62% of the particle size, and the ball mill is loaded with steel balls.

[0008] In step S2, the pressure of the first hydrocyclone is controlled at 0.05 MPa, and the particle size of the graded product is controlled to be below 0.2 mm as the overflow product and the particle size of the product above 0.2 mm as the underflow product. The overflow product is the qualified particle size required for subsequent processes.

[0009] In step S3, particles with a screening size of less than 0.25mm are classified as undersize products, and particles with a size of more than 0.25mm are classified as oversize products.

[0010] In step S5, the underflow of the first hydrocyclone is controlled to have a -0.2mm particle size ratio of ≥78% and a -0.038mm particle size ratio of 16%~18%. The overflow of the first hydrocyclone is controlled to have a -0.038mm particle size ratio of ≥98%. The pressure of the first hydrocyclone is controlled to be 0.15MPa and the diameter of the sand discharge nozzle is 45mm.

[0011] In step S6, polyacrylamide and polyaluminum chloride are added to the first deep cone thickener for sedimentation and concentration treatment to obtain a deep cone underflow with a concentration of 25%~28%.

[0012] In step S7, the dispersant is a reinforced dispersant that uses at least two single dispersants in combination.

[0013] The process further includes step S11, in which the tailings product obtained in step S10 is fed into the second scavenging operation, and the resulting foam product is the middlings product of the second scavenging operation, while the other part is the tailings product of the second scavenging operation; the middlings product obtained in the second scavenging operation and the roughing tailings product in step S8 are combined for the first scavenging operation.

[0014] The process further includes step S12, in which the scavenged tailings product obtained in step S11 is fed into a high-gradient magnetic separator. The resulting high-gradient magnetic material is combined with the middlings from the shaking table in step S4 and fed into a second hydrocyclone. The underflow from the second hydrocyclone is returned to the ball mill for regrinding, and the overflow from the second hydrocyclone is fed into the discharge pump pool of the ball mill. The high-gradient non-magnetic material is fed into the next process.

[0015] The process further includes step S13, where the high-gradient non-magnetic material obtained in step S12 is fed into a two-stage hydrocyclone for classification, removing some fine mud. The underflow from the two-stage hydrocyclone is fed into a belt filter for dewatering, yielding a high-whiteness feldspar product. The filtrate is returned to the circulating water tank. The overflow from the two-stage hydrocyclone is fed into a second deep cone thickener for concentration. In step S14, the underflow from the second deep cone thickener in step S13 is fed into a plate and frame filter press to obtain an ultrafine feldspar product. The filtrate is returned to the circulating water tank.

[0016] The beneficial effects of this invention are as follows: This invention can improve the recovery rate of lepidolite and simultaneously enhance the whiteness of feldspar after flotation. It innovatively employs a fine mud pretreatment step before the conventional lepidolite flotation process, using dispersants and complementary collectors to first complete the dispersion and floatability enhancement pretreatment of the fine mud. Then, the treated fine mud is co-fed with coarse slurry into the conventional flotation system, achieving efficient recovery of lepidolite across all particle sizes (coarse particles + fine mud), maximizing the utilization of resources across all particle sizes, and significantly improving the overall recovery rate of lepidolite. This invention uses a combination of dispersants and complementary collectors. The dispersant specifically addresses the dispersion requirements of the fine mud pretreatment, while the complementary collector, through component synergy, considers the collection needs of both fine mud and coarse lepidolite, solving the problems of poor compatibility and poor separation effect of conventional single reagents, and significantly improving separation efficiency and recovery rate stability.

[0017] After flotation, this invention introduces a new feldspar hydrocyclone desliming process. This process utilizes centrifugal grading to efficiently remove fine mud impurities adhering to the surface of feldspar without the need for additional reagents. This significantly improves the whiteness of feldspar, solves the problem of feldspar quality improvement, and allows for the production of products with corresponding whiteness according to market demand. This enables the resource utilization of feldspar resources, improves the overall economic efficiency of the process, and fills the technological gap of simultaneous quality improvement and synergistic utilization of lepidolite flotation and feldspar.

[0018] This invention uses dispersants and complementary collectors without toxic or harmful components. Flotation wastewater and hydrocyclone overflow can be recycled. No additional pollutants are generated during the fine mud pretreatment and feldspar desliming process. The mud control treatment during grinding reduces the fine mud load. The overall process has low energy consumption and low pollution, realizing the green and efficient development of lepidolite and feldspar resources, and synergistic quality improvement and efficiency enhancement.

[0019] This invention is adaptable to lepidolite ore with different fine mud content and different dissemination characteristics. Whether it is fine-grained dissemination type, coarse-fine mixed type or high mud type lepidolite ore, stable full particle size recovery and recovery rate improvement can be achieved by adjusting the parameters of fine mud pretreatment and optimizing the ratio of complementary collectors. At the same time, by adjusting the hydrocyclone parameters, it can be adapted to tailings with different feldspar contents to ensure stable feldspar whitening effect. Attached Figure Description

[0020] Figure 1 is a schematic flowchart of the full-size flotation process for improving the recovery rate of lepidolite through fine mud pretreatment according to the present invention. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] Referring to Figure 1, the full-size flotation process method for improving the recovery rate of lepidolite by fine mud pretreatment according to the present invention specifically includes the following steps: Step S1, the crushed lepidolite ore is conveyed to a ball mill by a belt conveyor for grinding. Preferably, the lepidolite ore in the grinding product has a particle size of ≤5mm and a particle size ratio of more than 62%. The ball mill is loaded with steel balls.

[0023] In step S2, the grinding product obtained in step S1 is pumped to a first hydrocyclone for classification. The pressure of the first hydrocyclone is controlled at 0.05 MPa. After classification, the first hydrocyclone produces underflow and overflow products. Preferably, the overflow product is controlled to have a particle size of less than 0.2 mm, and the underflow product is controlled to have a particle size greater than 0.2 mm. The overflow product is the qualified particle size required for subsequent processes.

[0024] Step S3: The underflow product from the first hydrocyclone obtained in step S2 is fed into a five-layer high-frequency vibrating screen for classification, yielding undersize and oversize products. The particle size is controlled to be below 0.25mm for undersize and above 0.25mm for oversize. The oversize product from the high-frequency vibrating screen is returned to the ball mill for regrinding, forming a closed-loop classification system with the ball mill. The undersize product from the high-frequency vibrating screen is combined with the overflow product from the first hydrocyclone in step S2 and fed into a weak magnetic separator for iron removal, yielding non-magnetic and magnetic materials.

[0025] In step S4, the non-magnetic material after iron removal in step S3 is fed into a cloth sluice, while the magnetic material is used as the iron concentrate product. The cloth sluice concentrate is subjected to roughing and re-selection on a shaking table to obtain a tantalum-niobium-tin concentrate product. The middle ore from the shaking table is fed into the pump pool of the second hydrocyclone, and the cloth sluice tailings enter the next process.

[0026] In step S5, the tailings obtained in step S4, along with the roughing tailings and re-selection tailings from the shaking table, are fed into a first-stage hydrocyclone to obtain the underflow and overflow of the first-stage hydrocyclone. The underflow of the first-stage hydrocyclone controls the proportion of -0.2mm particles to be ≥78%, and the proportion of -0.038mm particles to be 16%~18%. The overflow of the first-stage hydrocyclone controls the proportion of -0.038mm particles to be ≥98%. Preferably, the pressure of the first-stage hydrocyclone is controlled at 0.15MPa, and the diameter of the underflow nozzle is 45mm.

[0027] Step S6: The overflow from the hydrocyclone obtained in step S5 is fed into the first deep cone thickener for sedimentation and concentration. Preferably, polyacrylamide and polyaluminum chloride are added to the first deep cone thickener for sedimentation and concentration treatment to obtain a deep cone underflow with a concentration of 25%~28%. The deep cone overflow is returned to the circulating water tank as return water.

[0028] Step S7: The deep cone bottom flow obtained in step S6 is added to the fine mud pretreatment tank. A dispersant is added to the fine mud pretreatment tank and stirred evenly for pretreatment to obtain pretreated fine mud. Preferably, the dispersant is a reinforced dispersant using at least two single dispersants in combination to achieve the process effect of thoroughly dispersing the fine mud.

[0029] Step S8: The hydrocyclone underflow obtained in step S5 and the pretreated fine mud mixed slurry obtained in step S7 are added to the flotation mixing tank. A compatible collector is added to the flotation mixing tank, and after thorough mixing, full-size flotation is performed. Roughing is carried out, and the resulting froth product is the lepidolite roughing concentrate product; the remaining portion is the roughing tailings product.

[0030] Step S9: The rough concentrate product from step S8 is fed into the first fine-tuning operation, and the resulting foam product is the first fine-tuning concentrate product, while the remaining portion is the first fine-tuning middlings product. The first fine-tuning concentrate product is then fed into the second fine-tuning operation, and the resulting foam product is the second fine-tuning concentrate product of lepidolite. The second fine-tuning concentrate product of lepidolite is dewatered using a belt filter to obtain the lepidolite concentrate product, while the remaining portion is the second fine-tuning middlings product of lepidolite. The second fine-tuning middlings product of lepidolite is then combined with the rough concentrate product from step S8 to perform the first fine-tuning operation, forming a closed-loop operation.

[0031] In step S10, the roughing tailings product from step S8 is fed into the scavenging operation, and the resulting froth product is the middlings product of scavenging operation, while the other part is the tailings product of scavenging operation. The middlings product of scavenging operation and the middlings product of fine flotation operation obtained in step S9 are combined and fed back into the roughing operation to form a large closed-loop flotation system.

[0032] Step S11: The tailings product obtained in step S10 is fed into the second scavenging operation. The resulting foam product is the middlings product of the second scavenging operation, and the rest is the tailings product of the second scavenging operation. The middlings product obtained in the second scavenging operation and the roughing tailings product in step S8 are combined for the first scavenging operation.

[0033] In step S12, the scavenged tailings product obtained in step S11 is fed into a high-gradient magnetic separator. The resulting high-gradient magnetic material is combined with the middlings from the shaking table in step S4 and fed into a second hydrocyclone. The underflow from the second hydrocyclone is returned to the ball mill for regrinding, and the overflow from the second hydrocyclone is fed into the discharge pump pool of the ball mill. The high-gradient non-magnetic material is fed into the next process.

[0034] In step S13, the high-gradient non-magnetic material obtained in step S12 is fed into a two-stage hydrocyclone for classification treatment to remove some fine mud. The underflow from the two-stage hydrocyclone is fed into a belt filter for dewatering to obtain a high-whiteness feldspar product. The filtrate is returned to the circulating water tank. The overflow from the two-stage hydrocyclone is fed into a second deep cone thickener for concentration.

[0035] In step S14, the underflow from the second deep cone thickener in step S13 is fed into a plate and frame filter press to obtain ultrafine feldspar product, and the filtrate is returned to the circulating water tank.

[0036] This invention feeds the raw ore slurry into a hydrocyclone for preliminary desliming. The deslimed fine mud is then concentrated using a deep cone thickener. The concentrated fine mud is fed into a fine mud pretreatment tank, where a dispersant is added preferentially. The mixture is stirred for 15-25 minutes to adjust the slurry concentration to 20%-30% and the pH to 7-8, achieving efficient dispersion of fine mud particles and preventing recovery difficulties caused by fine mud agglomeration. The combined dispersion efficiency is superior to that of conventional single dispersants, effectively breaking up fine mud agglomerates. Compared to conventional flotation processes, this invention increases the total recovery rate of lepidolite by more than 5%, reaching a maximum of over 82%, and is particularly suitable for lepidolite ores with high fine mud content, significantly improving resource utilization and achieving the core objective of increased recovery rate. While improving the recovery rate of lepidolite of all particle sizes, this invention effectively inhibits the flotation of gangue minerals, ultimately increasing the grade of lepidolite concentrate by 0.2%-0.3%, achieving a dual improvement in recovery rate and concentrate quality. The separation index fluctuates little, and the recovery rate is highly controllable.

[0037] This invention feeds the scavenged feldspar enriched slurry into a hydrocyclone, adjusting the feed concentration to 30-35% and the hydrocyclone pressure to 0.15-0.2 MPa. Utilizing the centrifugal classification effect of the hydrocyclone, fine mud impurities and fine gangue particles adhering to the feldspar surface are discharged with the overflow, resulting in a deslimed feldspar slurry. The deslimed feldspar slurry is then filtered and dried to obtain a high-whiteness feldspar product, with whiteness increased by 5% to 10%, meeting industrial-grade application standards.

[0038] This invention can improve the recovery rate of lepidolite and simultaneously enhance the whiteness of feldspar after flotation. It innovatively adopts a fine mud pretreatment step before the conventional lepidolite flotation process. Using dispersants and complementary collectors, the fine mud is first dispersed and its floatability is enhanced. Then, the qualified fine mud is sent to the conventional flotation system together with the coarse slurry, realizing the efficient recovery of lepidolite of all particle sizes (coarse particles + fine mud), maximizing the utilization of resources of all particle sizes, and significantly improving the overall recovery rate of lepidolite.

[0039] This invention directly feeds a pre-treated "fine mud + coarse particle" mixed slurry into a conventional flotation mixing tank, adds an appropriate amount of complementary collector, and after uniform mixing, performs conventional coarse particle flotation. At this point, the pre-dispersed fine mud lepidolite can be collected simultaneously with the coarse lepidolite. The complementary collector, through the synergistic effect of its components, selectively enhances the hydrophobicity of the two types of particles, significantly improving the collection efficiency of lepidolite of all particle sizes. Simultaneously, it effectively inhibits the flotation of gangue minerals such as feldspar and quartz, reducing the mixing and loss of lepidolite and gangue, resulting in a full-size lepidolite concentrate and flotation tailings. This invention uses a combination of dispersant and complementary collector. The dispersant specifically addresses the dispersion requirements of the fine mud pretreatment, while the complementary collector, through component synergy, takes into account the collection needs of both fine mud and coarse lepidolite, solving the problems of poor compatibility and poor separation effect of conventional single reagents, and significantly improving separation efficiency and recovery stability.

[0040] This invention utilizes a pretreatment process to thoroughly disperse fine mud using a dispersant, preventing agglomeration and surface covering, thus optimizing the separation environment for subsequent conventional flotation. Combined with the efficient collection of a compatible collector, it ensures that both coarse and fine lepidolite particles can be efficiently and stably collected, resolving the detrimental effects of fine mud on flotation and achieving a stable increase in recovery rate.

[0041] After flotation, this invention introduces a new feldspar hydrocyclone desliming process. This process utilizes centrifugal grading to efficiently remove fine mud impurities adhering to the surface of feldspar without the need for additional reagents. This significantly improves the whiteness of feldspar, solves the problem of feldspar quality improvement, and allows for the production of products with corresponding whiteness according to market demand. This enables the resource utilization of feldspar resources, improves the overall economic efficiency of the process, and fills the technological gap of simultaneous quality improvement and synergistic utilization of lepidolite flotation and feldspar.

[0042] This invention uses dispersants and complementary collectors without toxic or harmful components. Flotation wastewater and hydrocyclone overflow can be recycled. No additional pollutants are generated during the fine mud pretreatment and feldspar desliming process. The mud control treatment during grinding reduces the fine mud load. The overall process has low energy consumption and low pollution, realizing the green and efficient development of lepidolite and feldspar resources, and synergistic quality improvement and efficiency enhancement.

[0043] This invention is adaptable to lepidolite ore with different fine mud content and different dissemination characteristics. Whether it is fine-grained dissemination type, coarse-fine mixed type or high mud type lepidolite ore, stable full particle size recovery and recovery rate improvement can be achieved by adjusting the parameters of fine mud pretreatment and optimizing the ratio of complementary collectors. At the same time, by adjusting the hydrocyclone parameters, it can be adapted to tailings with different feldspar contents to ensure stable feldspar whitening effect.

[0044] In this invention, the scavenged tailings product obtained in step S11 is fed into a high-gradient magnetic separator. The resulting high-gradient magnetic material is combined with the middlings from the shaking table in step S4 and fed into a second hydrocyclone. The underflow from the second hydrocyclone is returned to the ball mill for re-grinding, and the overflow from the second hydrocyclone is fed into the ball mill, thus realizing a large-scale circulation of the entire process and fully recovering the mineral components.

[0045] To verify the effectiveness of the invention, a comparative experiment with equal proportions was conducted, and the following comparative groups were set up: Comparative Example 1 used feldspar and lepidolite products obtained by desliming and flotation after grinding and classification, and then subjecting the flotation tailings to strong magnetic separation. Grinding was performed using a ball mill, screening was done using a five-layer high-frequency vibrating screen with a 0.3×3.2mm mesh, the feed concentration was controlled within the range of 35%-40%, the vibration frequency and amplitude were controlled at 25Hz and 1-2mm respectively, desliming was performed using a hydrocyclone, and flotation adopted a closed-loop process of one roughing, two scavenging, and two cleaning stages, including the addition of collectors and dispersants. The roughing time was 4-6 minutes, the flotation machine operating frequency was 50Hz, the aeration rate was 800-900 Nm³ / min, and the flotation temperature was controlled at 18-25℃. The strong magnetic separation used a magnetic field strength of 1.5T, a rotor speed controlled at 2.5-3.5 r / min, and an operating current of 1410A.

[0046] The feldspar products obtained from the two groups were measured and recorded. The test results of Comparative Example 1 and the embodiment of this patent are shown in Table 1 below. The lepidolite products and flotation tailings obtained from the two groups were measured and statistically analyzed. The test results of Comparative Example 1 and the embodiment of this patent are shown in Table 2 below.

[0047] Table 1. Name, Whiteness, Lithium Oxide (%), Ferric Oxide (%). This Example: Raw Ore 200.45 0.65. This Example: Tailings (High Whiteness Feldspar) 650.04 0.06. Comparative Example 1: Raw Ore 200.45 0.65. Comparative Example 1: Tailings (Feldspar Product) 550.06 0.12. As shown in Table 1 above, the whiteness of the high-white feldspar product obtained in this patent embodiment reaches 65, which is significantly improved compared to the whiteness of 55 in the comparative example. This achieves the product characteristics of improving whiteness and reaching a high level. The content of ferric oxide is 0.06%, which is significantly reduced compared to 0.12% in the comparative example, achieving the product characteristics of low iron content.

[0048] Table 2. Name | Yield % | Lithium Oxide % | Recovery % | Example Concentrate (Lepidolite) | 17.5 | 2.0 | 7 | 8 | 0.50 | Example Tailings | / | 0.05 | / | Example Raw Ore | / | 0.45 | / | Comparative Example 1 Concentrate (Lepidolite) | 16.5 | 2.0 | 4 | 7 | 4.8 | Comparative Example 1 Tailings | / | 0.07 | / | Comparative Example 1 Raw Ore | / | 0.45 | / As shown in Table 2 above, the recovery rate of lepidolite concentrate obtained in this patent embodiment reaches 80.50%, the lithium oxide content in the obtained lepidolite concentrate reaches 2.07%, and the content in the tailings is relatively low at 0.04%, which is a high level. Compared with the 74.8% recovery rate of the comparative example, it is a significant improvement, realizing the process effect of improving the recovery rate of lepidolite. Therefore, the method of the present invention can achieve a good recovery rate of lepidolite concentrate from lithium-containing kaolin ore while producing high white feldspar, thus enabling efficient recovery of lithium resources.

[0049] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A full-size flotation process for improving the recovery rate of lepidolite through fine mud pretreatment, characterized in that, Specifically, the following steps are included: Step S1: The crushed lepidolite ore is fed into a ball mill for grinding. Step S2: The grinding product obtained in Step S1 is fed to a first hydrocyclone for classification. After classification, the first hydrocyclone produces underflow and overflow products. Step S3: The underflow product from the first hydrocyclone obtained in Step S2 is fed into a five-layer high-frequency vibrating screen for classification, producing underflow and overflow products. The overflow product from the high-frequency vibrating screen is returned to the ball mill for further grinding, forming a closed-loop classification system with the ball mill. The underflow product from the high-frequency vibrating screen and the overflow product from the first hydrocyclone in Step S2 are combined and fed into a weak magnetic separator for iron removal, producing non-magnetic and magnetic materials. Step S4: The non-magnetic material after iron removal in Step S3 is fed into a cloth sluice, and the magnetic material is used as the iron concentrate product. Bulu concentrate undergoes roughing and re-concentration on shaking tables to obtain tantalum-niobium-tin concentrate products. The middlings from the shaking tables are fed into the pump pool of the second hydrocyclone, while the Bulu tailings proceed to the next process. In step S5, the Bulu tailings obtained in step S4, along with the roughing and re-concentration tailings from the shaking tables, are fed into a first-stage hydrocyclone to obtain underflow and overflow. In step S6, the overflow from the first-stage hydrocyclone obtained in step S5 is fed into the first deep cone thickener for sedimentation and thickening. The deep cone overflow is returned to the circulating water tank as reclaimed water; in step S7, the deep cone underflow obtained in step S6 is added to the fine mud pretreatment tank, and a dispersant is added to the fine mud pretreatment tank for uniform pretreatment to obtain pretreated fine mud; in step S8, the mixed slurry of the hydrocyclone underflow obtained in step S5 and the pretreated fine mud obtained in step S7 is added to the flotation mixing tank, and a compatible collector is added to the flotation mixing tank. After uniform mixing, flotation is performed for roughing to obtain... The obtained foam product is the lepidolite roughing concentrate product, and the other part is the roughing tailings product; in step S9, the roughing concentrate product from step S8 is fed into the first cleaning operation, and the obtained foam product is the first cleaning concentrate product, and the other part is the first cleaning middlings product; the first cleaning concentrate product is fed into the second cleaning operation, and the obtained foam product is the lepidolite second cleaning concentrate product. The lepidolite second cleaning concentrate product is dewatered by a belt filter to obtain lepidolite concentrate product, and the other part is the second cleaning middlings product; the second cleaning middlings product is combined with the roughing concentrate product from step S8 for the first cleaning operation to form a closed-loop operation; in step S10, the roughing tailings product from step S8 is fed into the first scavenging operation, and the obtained foam product is the first scavenging middlings product, and the other part is the first scavenging tailings product; the obtained first scavenging middlings product and the first cleaning middlings product obtained in step S9 are combined and fed back into the roughing operation to form a large closed-loop flotation system.

2. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S1, the lithium mica ore in the grinding product has a particle size of ≤5mm, accounting for more than 62%, and the ball mill is loaded with steel balls.

3. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S2, the pressure of the first hydrocyclone is controlled at 0.05 MPa, and the particle size of the graded product is controlled to be below 0.2 mm as the overflow product and the particle size of the product above 0.2 mm as the underflow product. The overflow product is the qualified particle size required for subsequent processes.

4. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S3, particles with a screening size of less than 0.25mm are classified as undersize products, and particles with a size of more than 0.25mm are classified as oversize products.

5. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S5, the underflow of the first hydrocyclone is controlled to have a -0.2mm particle size ratio of ≥78% and a -0.038mm particle size ratio of 16%~18%. The overflow of the first hydrocyclone is controlled to have a -0.038mm particle size ratio of ≥98%. The pressure of the first hydrocyclone is controlled to be 0.15MPa and the diameter of the sand discharge nozzle is 45mm.

6. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S6, polyacrylamide and polyaluminum chloride are added to the first deep cone thickener for sedimentation and concentration treatment to obtain a deep cone underflow with a concentration of 25%~28%.

7. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, In step S7, the dispersant is a reinforced dispersant that uses at least two single dispersants in combination.

8. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 1, characterized in that, The process further includes step S11, in which the tailings product obtained in step S10 is fed into the second scavenging operation, and the resulting foam product is the middlings product of the second scavenging operation, while the other part is the tailings product of the second scavenging operation; the middlings product obtained in the second scavenging operation and the roughing tailings product in step S8 are combined for the first scavenging operation.

9. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 8, characterized in that, The process further includes step S12, in which the scavenged tailings product obtained in step S11 is fed into a high-gradient magnetic separator. The resulting high-gradient magnetic material is combined with the middlings from the shaking table in step S4 and fed into a second hydrocyclone. The underflow from the second hydrocyclone is returned to the ball mill for regrinding, and the overflow from the second hydrocyclone is fed into the discharge pump pool of the ball mill. The high-gradient non-magnetic material is fed into the next process.

10. The full-size flotation process for improving lepidolite recovery rate through fine mud pretreatment according to claim 9, characterized in that, Further steps include: Step S13, where the high-gradient non-magnetic material obtained in Step S12 is fed into a two-stage hydrocyclone for classification, removing some fine mud. The underflow from the two-stage hydrocyclone is fed into a belt filter for dewatering, yielding a high-whiteness feldspar product. The filtrate is returned to the circulating water tank. The overflow from the two-stage hydrocyclone is fed into a second deep cone thickener for concentration. Step S14, where the underflow from the second deep cone thickener in Step S13 is fed into a plate and frame filter press, yielding an ultrafine feldspar product. The filtrate is returned to the circulating water tank.

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