Process for the recovery of lithium concentrates from lithium-bearing ores

Abstract

The application discloses a method for recovering lithium concentrate from lithium-containing ores. The method comprises the following steps: adopting a SABC crushing and grinding system to perform crushing and grinding treatment on the lithium-containing ores to obtain material with a particle size of no more than 0.25 mm; performing first magnetic separation treatment on the material to obtain first magnetic minerals and first non-magnetic minerals; performing gravity separation treatment on the first non-magnetic minerals to obtain gravity separation non-lithium concentrate and gravity separation tailings, wherein the gravity separation treatment comprises in-sequence cloth apron chute treatment and table treatment; performing desliming classification treatment on the gravity separation tailings to obtain ore sand and ore slime; and performing flotation treatment on the ore sand to obtain lithium concentrate. The method not only has simple production process and low production cost, but also is beneficial to improving the recovery rate of lithium-containing ores, especially super-low-grade lithium-containing ores, and the grade of lithium concentrate, effectively enhancing the resource comprehensive utilization rate and the anti-risk response capability, activating the difficult-to-mine dead ores, and realizing full resource utilization of low-grade lithium-containing ores.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mineral processing, and in particular relates to a method for recovering lithium concentrate from lithium-containing ores. BACKGROUND

[0002] The average grade of the developed lithium ore is mostly above 0.5% (calculated as Li2O), the useful mineral composition of the ore is simple (containing lithium mica), the pure mineral grade is high (containing Li2O about 3.2%), and the embedded particle size is coarse (the useful mineral embedded particle size is above 0.35 mm). The traditional mineral processing process is complex, the process is not smooth, the operation and management are difficult, the production cost is high, the product quality is poor, and the recovery index is low. At present, the large-scale ultra-low grade (Li2O content below 0.4%) porcelain stone ore in a certain mine area in Jiangxi is a "dead ore", or is only sold to the construction and ceramic industries at a low price as a low-end product. At present, clean energy has replaced fossil energy, and with the rapid development of the new energy lithium industry, the demand for lithium has increased exponentially, and the price of lithium concentrate has soared. Therefore, under the situation of serious shortage of lithium raw materials, the ultra-low grade lithium ore resources need to be developed and utilized. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, one object of the present application is to propose a method for recovering lithium concentrate from lithium-containing ores. The method not only has a simple production process and low production cost, but also is beneficial to improve the recovery rate of lithium-containing ores (especially ultra-low grade lithium-containing ores) and the grade of lithium concentrate, effectively enhance the resource comprehensive utilization rate and risk resistance, activate the "dead ore" with high mineral processing difficulty, realize the full resource utilization of low-grade lithium-containing ores, and convert resource advantages into economic advantages.

[0004] In one aspect of the present application, the present application proposes a method for recovering lithium concentrate from lithium-containing ores. According to an embodiment of the present application, the method comprises:

[0005] (1) adopting a SABC crushing and grinding system to perform crushing and grinding treatment on the lithium-containing ores, so as to obtain a material with a particle size of no more than 0.25 mm;

[0006] (2) performing first magnetic separation treatment on the material, so as to obtain first magnetic minerals and first non-magnetic minerals;

[0007] (3) performing gravity separation treatment on the first non-magnetic minerals, so as to obtain gravity separation non-lithium concentrate and gravity separation tailings, the gravity separation treatment comprising in-sequence clothed chute treatment and table treatment;

[0008] (4) performing desliming classification treatment on the gravity separation tailings, so as to obtain ore sand and ore slime;

[0009] (5) subjecting the ore sand to a flotation process to obtain a lithium concentrate.

[0010] According to the method for recovering lithium concentrate from lithium-containing ore in the above-mentioned embodiments of the present application, the lithium-containing ore is subjected to crushing and grinding treatment by using the SABC crushing and grinding system, compared with the conventional crushing and grinding process (such as the old three-stage crushing + ball milling process), not only the process flow is simple, the degree of automation is high, the operating environment is good, and the dust is less, but also the risk of medium and fine particle blockage of equipment can be effectively avoided or reduced, the treatment process is smooth and stable, and the capacity is high; in addition, the SABC crushing and grinding system can select whether to crush through the hard stone crushing device according to the severity of weathering of the lithium-containing ore and the size of the hardness of the ore, and the actual situation such as the hardness and accumulation of the ore discharged from the semi-autogenous mill can be flexibly selected, among them, for the hard-to-grind ore, the accumulation of the hard-to-grind ore in the semi-autogenous mill can be effectively reduced by hard stone crushing treatment, which is conducive to fully exerting the grinding efficiency, at the same time, for the lithium-containing ore which does not need to be subjected to hard stone crushing, it can be directly treated by SAB process, thereby not only the operation process can be simplified, the energy consumption can be reduced, but also the flexible switching between SABC process and SAB process can be realized according to the change of hard stone yield, which is helpful to enhance the self-adaptability of the crushing and grinding treatment, and thus is conducive to improving the recovery rate and concentrate grade of the lithium-containing ore, and is helpful to enhance the comprehensive utilization rate of resources, and thus realizes the full resource utilization of the lithium-containing ore, especially the ultra-low grade lithium-containing ore, and changes the resource advantage into economic advantage; in addition, in the present application, the first non-magnetic separation mineral is subjected to gravity separation treatment by using the sequentially performed cloth chute treatment and table treatment, which is conducive to improving the enrichment ratio of the gravity separation non-lithium concentrate, not only the amount of ore entering the table can be reduced, the number of tables can be reduced, and the labor intensity of workers can be reduced, but also the recovery amount of fine and fine particle useful minerals can be increased, the recovery effect and efficiency of the gravity separation non-lithium concentrate can be improved, and the resource utilization rate of the lithium-containing ore can be improved; in addition, in the present application, the lithium-containing ore is ground to not more than 0.25 mm, which can also realize the effective recovery of useful minerals with small embedded particle size, and thus can further improve the resource utilization of the lithium-containing ore, especially the ultra-low grade lithium-containing ore. In summary, compared with the prior art, the method for recovering lithium concentrate in the present application can not only have simple production process and low production cost, but also be conducive to improving the recovery rate of lithium-containing ore (especially ultra-low grade lithium-containing ore) and the grade of lithium concentrate, and can effectively enhance the comprehensive utilization rate of resources and the risk resistance ability, activate the "stale ore" with high beneficiation difficulty, and realize the transformation of resource advantage into economic advantage.

[0011] In addition, the method for recovering lithium concentrate from lithium-containing ore according to the above-mentioned embodiments of the present application can also have the following additional technical features:

[0012] In some embodiments of the present application, in step (1), the crushing and grinding treatment comprises: (1-1) performing semi-autogenous grinding treatment on the lithium-containing ore; (1-2) performing screening treatment on the semi-autogenous grinding product to obtain first oversize and first undersize; (1-3) based on the particle size and weathering degree of the first undersize, selecting to return the first oversize to step (1-1) to continue the semi-autogenous grinding treatment, or first feeding the first oversize to a hard stone crushing device to perform crushing treatment, and then returning the crushing product to step (1-1) to continue the semi-autogenous grinding treatment; (1-4) performing classification treatment on the first undersize by using a cyclone group to obtain material with ore particle size not greater than 0.25 mm and material with ore particle size greater than 0.25 mm; (1-5) performing ball milling treatment on the material with ore particle size greater than 0.25 mm, and returning the ball milling product to step (1-4) to perform the classification treatment.

[0013] In some embodiments of the present application, in step (1-1), the lithium-containing ore is subjected to coarse crushing treatment before the semi-autogenous grinding treatment.

[0014] In some embodiments of the present application, in step (1-2), the particle size of the first undersize is not greater than 4 mm.

[0015] In some embodiments of the present application, in step (2), the magnetic field strength of the first magnetic separation is 3000-4000 Gs.

[0016] In some embodiments of the present application, in step (3), the gravity separation treatment comprises: (3-1) performing apron chute treatment on the first magnetic mineral to obtain heavy slurry and light slurry; (3-2) performing first thickening treatment on the heavy slurry to obtain thickened heavy slurry; (3-3) performing first table treatment on the thickened heavy slurry to obtain first table concentrate and first table tailings; (3-4) performing second table treatment on the first table concentrate to obtain the gravity separation non-lithium concentrate and second table tailings.

[0017] In some embodiments of the present application, in step (3-3), the first table tailings are returned to step (3-1) to perform the apron chute treatment.

[0018] In some embodiments of the present application, in step (3-4), the second table tailings are returned to step (3-1) to perform the apron chute treatment.

[0019] In some embodiments of the present application, step (4) further comprises: (4-1) performing a second thickening treatment on the slime to obtain a thickened slime; (4-2) performing a second magnetic separation treatment on the thickened slime to obtain second magnetic minerals and second non-magnetic minerals; (4-3) performing a first dewatering treatment on the non-magnetic minerals to obtain a product containing feldspar.

[0020] In some embodiments of the present application, the particle size of the slime is not greater than 0.025 mm.

[0021] In some embodiments of the present application, in step (4-2), the magnetic field strength of the second magnetic separation is 1.3-1.5 T.

[0022] In some embodiments of the present application, in step (4-2), the second magnetic minerals are fed to step (5) for the flotation treatment.

[0023] In some embodiments of the present application, in step (4), the gravity separation tailings are subjected to cyclone desliming classification treatment by using a cyclone group to obtain the ore sand and the slime.

[0024] In some embodiments of the present application, in step (5), the flotation treatment comprises: (5-1) performing a roughing treatment on the ore sand to obtain a roughing concentrate and a roughing tailings; (5-2) performing a first cleaning treatment on the roughing concentrate to obtain a first concentrate and a first cleaning tailings; (5-3) performing a second cleaning treatment on the first concentrate to obtain a second concentrate and a second cleaning tailings; (5-4) performing a first scavenging treatment on the roughing tailings to obtain a first scavenging concentrate and a first scavenging tailings; (5-5) performing a second scavenging treatment on the first scavenging tailings to obtain a second scavenging concentrate and a second scavenging tailings; (5-6) performing a second dewatering treatment on the second concentrate to obtain the lithium concentrate.

[0025] In some embodiments of the present application, step (5) further comprises: (5-7) performing a third magnetic separation treatment on the second scavenging tailings to obtain third magnetic minerals and third non-magnetic minerals; (5-8) performing a third dewatering treatment on the third non-magnetic minerals to obtain a product containing feldspar.

[0026] In some embodiments of the present application, in step (5-2), the first cleaning tailings are returned to step (5-1) for the roughing treatment.

[0027] In some embodiments of the present application, in step (5-3), the second cleaning tailings are returned to step (5-2) for the first cleaning treatment.

[0028] In some embodiments of the present application, in step (5-4), the first scavenging concentrate is returned to step (5-1) for the roughing treatment.

[0029] In some embodiments of the present application, in step (5-5), the second scavenging concentrate is returned to step (5-4) for the first scavenging treatment.

[0030] In some embodiments of the present application, in step (5-7), the third magnetic field strength of the magnetic treatment is 1.3-1.5T.

[0031] In some embodiments of the present application, in step (5-8), the third magnetic mineral is returned to step (1) for the crushing and grinding treatment.

[0032] In some embodiments of the present application, the lithium-containing ore includes at least one of lepidolite, eisenlepidolite and lithia.

[0033] In some embodiments of the present application, the raw ore grade of the lithium-containing ore is not more than 0.4% in terms of Li2O.

[0034] In some embodiments of the present application, the pure ore theoretical grade of the lithium-containing ore is not higher than 1.9% in terms of Li2O.

[0035] In some embodiments of the present application, the embedded particle size of the useful mineral in the lithium-containing ore is not more than 0.3mm in terms of Li2O.

[0036] In some embodiments of the present application, the gravity non-lithium concentrate is a tantalum-tin mixed concentrate, and the content of tantalum in the tantalum-tin mixed concentrate is 5-10%.

[0037] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0039] Fig. 1 is a flow chart of a method for recovering lithium concentrate from lithium-containing ore according to one embodiment of the present application;

[0040] Fig. 2 is a flow chart of a method for recovering lithium concentrate from lithium-containing ore according to another embodiment of the present application. DETAILED DESCRIPTION

[0041] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations throughout the attached drawing figures. The embodiments described below are exemplary in nature, and are intended to be illustrative of the present application rather than to limit the same. Additionally, the terms "first", "second", and the like, are used merely as labels, and are not intended to signify relative importance or a quantity of the indicated number. Thus, a feature labeled as "first" or "second" can implicitly or explicitly include at least one of the feature. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, and the like, unless otherwise specifically defined.

[0042] In one aspect of the present application, the present application proposes a method for recovering lithium concentrate from lithium-containing ores. According to embodiments of the present application, in combination with Figs. 1-2 It is understood that the method comprises:

[0043] S100: adopting a SABC crushing and grinding system to perform crushing and grinding treatment on the lithium-containing ores, so as to obtain materials with a particle size of no more than 0.25 mm

[0044] According to embodiments of the present application, by adopting a SABC crushing and grinding system to perform crushing and grinding treatment on the lithium-containing ores, compared with conventional crushing and grinding processes (such as the old three-stage crushing + ball milling process), not only the process flow is simple, the degree of automation is high, the operating environment is good, the dust is less, but also the risk of medium and fine particle blockage of equipment can be effectively avoided or reduced, the treatment process is smooth and stable, and the production capacity is high. In addition, the SABC crushing and grinding system can select whether to perform crushing through a hard stone crushing device according to the severity of weathering of the lithium-containing ores and the size of the hardness of the ores, and the actual situation such as the hardness and accumulation of the ores discharged from the semi-autogenous mill can be flexibly selected. For difficult-to-grind ores, hard stone crushing treatment can effectively reduce the accumulation of difficult-to-grind ores in the semi-autogenous mill, which is conducive to fully exerting the grinding efficiency. At the same time, for lithium-containing ores that do not need to be crushed, the SAB process can be directly performed, thereby not only simplifying the operation process and reducing energy consumption, but also realizing flexible switching between the SABC process and the SAB process according to the change of the hard stone yield, which helps to enhance the adaptability of the crushing and grinding treatment, and further helps to improve the recovery rate and concentrate grade of the lithium-containing ores, and helps to enhance the comprehensive utilization rate of resources, and further realizes the full resource utilization of lithium-containing ores, especially super-low grade lithium-containing ores, and converts resource advantages into economic advantages.

[0045] According to embodiments of the present application, in combination with Fig. 2 It is understood that the specific process of adopting a SABC crushing and grinding system to perform crushing and grinding treatment on the lithium-containing ores can comprise:

[0046] (i): Coarse crushing of lithium-bearing ore breaks large pieces of ore into smaller pieces, thereby increasing the throughput of subsequent semi-autogenous grinding and reducing the unit energy consumption of the semi-autogenous grinding mill. It should be noted that there are no particular restrictions on the specific equipment used for coarse crushing, and those skilled in the art can choose flexibly according to the actual situation, such as using a jaw crusher or a gyratory crusher.

[0047] (ii): Semi-autogenous grinding of small lithium-bearing ore can be carried out by feeding small lithium-bearing ore into a semi-autogenous grinding mill. This process has a high degree of automation, less dust, a good operating environment, a large processing capacity, and a smooth and stable process.

[0048] (iii): The semi-autogenous grinding product is sieved to obtain the first sieve oversize. Fig. 2 The "+" in the middle indicates the material that passes through the sieve and the material that passes through the first sieve. Fig. 2 The "-" in the figure indicates the undersize material, which allows for the differentiation of semi-autogenous grinding products with significant particle size differences, enabling targeted subsequent processing and improving crushing efficiency and effectiveness. According to some specific examples of the present invention, the particle size of the obtained first undersize material can be no greater than 4 mm. This helps avoid the presence of large, difficult-to-grind pebbles in the first undersize material, which could affect the smoothness of the recovery process and the extraction effect of useful ore from the raw ore. Furthermore, it should be noted that the specific screening device is not particularly limited in the present invention; those skilled in the art can flexibly choose according to actual conditions, such as using a linear vibrating screen.

[0049] (iv): Based on the particle size and weathering degree of the material on the first screen, the material on the first screen can be selectively returned to step (ii) for further semi-autogenous grinding, or the material on the first screen can be fed to the rock crushing device for crushing, and then the crushed product can be returned to step (ii) for further semi-autogenous grinding. Specifically, the material on the first screen can be returned for semi-autogenous grinding again, which is beneficial to improve the semi-autogenous grinding effect and avoid or reduce the occurrence of insufficient grinding. For the material on the screen that is still difficult to grind thoroughly after one or more semi-autogenous grinding processes (such as "hard-to-grind large stones" with excessive particle size or high weathering degree), it can be fed to the crushing device for crushing, and then the crushed product can be semi-autogenous ground. This not only helps to improve the ore crushing effect, but also eliminates or reduces the accumulation of "hard-to-grind gravel" in the semi-autogenous grinder, which is beneficial to give full play to the efficiency of the mill.

[0050] (v): the first undersize is classified by using a cyclone group, to obtain material with ore particle size not greater than 0.25 mm and material with ore particle size greater than 0.25 mm, by classifying the first undersize, the reasonable grinding particle size can be controlled, which is beneficial to subsequent crushing treatment of ore particles with large particle size, thereby improving the particle size uniformity of the ore particles, in addition, it should be noted that the specific device for classification in the present application is not particularly limited, and the person skilled in the art can select flexibly according to the actual situation, preferably, a new long cone cyclone group can be used for intensive classification of the semi-autogenous grinding product, thereby further improving the classification effect, avoiding or reducing the overflow coarse or sand inclusion during subsequent desliming classification process, and creating favorable conditions for subsequent flotation treatment;

[0051] (vi): the material with ore particle size greater than 0.25 mm is ball milled, and the ball milling product is returned to step (v) for classification, thereby obtaining material with ore particle size not greater than 0.25 mm, by controlling the ore particle size in the final material to be not greater than 0.25 mm, the present application is beneficial to realizing the complete dissociation of useful minerals (especially for low-grade ore, complex ore composition and small embedded particle size of lithium-containing ore), improving the utilization rate of ore resources, avoiding over-grinding of the ore, causing unnecessary energy waste, and affecting the effect of subsequent flotation treatment. S200: the material is subjected to first magnetic separation to obtain first magnetic minerals and first non-magnetic minerals

[0052] According to the embodiments of the present application, by subjecting the material to first magnetic separation, part of the magnetic impurities in the material can be removed, which not only improves the ore processing capacity of the subsequent process, but also helps to ensure smooth operation of the system. Specifically, in combination with Figs. 1-2 It is understood that the magnetic field strength of the first magnetic separation can be 3000-4000Gs, for example, it can be 3000Gs, 3500Gs, 3600Gs or 4000Gs, etc., thereby effectively removing the magnetic minerals such as iron in the material, reducing the wear of the recovery device and the conveying pipeline by the broken steel balls, and prolonging the service life of the recovery system. In addition, a magnetic arc iron removal system can be arranged in the semi-autogenous grinding discharge area of the SABC crushing and grinding system, and / or a magnetic drum and an iron remover can be arranged after the recalcitrant stone crushing treatment and returned to the semi-autogenous grinding, thereby further strengthening the iron removal and ensuring the smooth operation of the recovery system.

[0053] S300: the first non-magnetic minerals are subjected to gravity separation to obtain gravity separation non-lithium concentrate and gravity separation tailings, the gravity separation includes in-sequence paving chute treatment and shaking table treatment

[0054] According to the embodiment of the present application, the first non-magnetic mineral is subjected to the re-election treatment by adopting the cloth apron chute treatment and the shaking table treatment in sequence, which is beneficial to improve the enrichment ratio of the re-election non-lithium concentrate, can not only reduce the amount of ore entering the shaking table, reduce the number of shaking tables, and reduce the labor intensity of workers, but also can increase the recovery amount of fine particle level useful minerals, improve the recovery effect and efficiency of the re-election non-lithium concentrate, and improve the resource utilization rate of lithium-containing ore. Specifically, in combination with Fig. 2 It is understood that the process of re-election treatment can include:

[0055] (I): the first magnetic mineral is subjected to the cloth apron chute treatment to obtain heavy slurry and light slurry. In the present application, the cloth apron chute treatment is adopted, which is beneficial to improve the enrichment ratio and improve the recovery effect of the heavy mineral, thereby the number of shaking tables required for subsequent shaking table treatment can be reduced, which can not only reduce the labor intensity of workers, but also improve the recovery effect of the re-election non-lithium concentrate. In addition, it should be noted that the specific device for the cloth apron chute treatment in the present application is not particularly limited, and the person skilled in the art can select it flexibly according to the actual situation. For example, a full-automatic cloth apron chute machine can be adopted, which is beneficial to improve the automation degree of the treatment process and improve the processing efficiency;

[0056] (II): the heavy slurry is subjected to the first thickening treatment to obtain thickened heavy slurry. In the present application, the thickening treatment is performed before the shaking table treatment, which can improve the shaking table feed concentration, is beneficial to avoid the tailings running water phenomenon in the shaking table treatment, effectively reduces the loss rate of fine particle level concentrate from the tailings end of the shaking table, and can further improve the recovery rate of the re-election non-lithium concentrate;

[0057] (III): the thickened heavy slurry is subjected to the first shaking table treatment to obtain the first shaking table concentrate and the first shaking table tailings. The first shaking table tailings can be preferably returned to step (I) for the cloth apron chute treatment, which can further increase the recovery yield of the re-election concentrate and improve the resource utilization rate;

[0058] (IV): the first shaking table concentrate is subjected to the second shaking table treatment to obtain the re-election non-lithium concentrate and the second shaking table tailings. The second shaking table tailings can be preferably returned to step (I) for the cloth apron chute treatment. In the present application, the two shaking table treatments are beneficial to improve the recovery rate of the useful mineral and avoid or reduce the loss of the useful mineral.

[0059] S400: the re-election tailings are subjected to the desliming classification treatment to obtain the ore sand and the ore slime

[0060] According to the embodiment of the present application, by performing desliming classification treatment on the gravity separation tailings, the loss of useful minerals is reduced and the interference of low-grade slurry materials on the subsequent flotation treatment process is reduced, wherein the ore sand is mainly used for recovering lithium concentrate, and the ore slurry is mainly used for recovering feldspar products. Further, according to some specific examples of the present application, the particle size of the slurry ore can be not greater than 0.025 mm, thereby further improving the efficiency and effect of the flotation treatment. In addition, it should be noted that the specific device used for desliming classification treatment in the present application is not particularly limited, and those skilled in the art can flexibly select according to the actual situation, for example, a new long cone cyclone group can be preferably used to perform desliming classification treatment on the gravity separation tailings, thereby not only improving the classification efficiency, but also improving the sand inclusion and overflow coarse phenomenon, reducing the loss of useful minerals caused by overflow coarse, and at the same time creating favorable conditions for subsequent flotation treatment, avoiding the interference of slurry materials on flotation, and improving the recovery rate of flotation treatment.

[0061] According to the embodiment of the present application, in combination with Fig. 2 It is understood that after the desliming classification treatment of the gravity separation tailings, the ore slurry can also be treated as follows:

[0062] (a): performing second thickening treatment on the ore slurry to obtain thickened ore slurry, by performing second thickening treatment on the slurry ore, the slurry concentration can be improved, thereby improving the subsequent dewatering effect and efficiency of the slurry ore;

[0063] (b): performing second magnetic separation treatment on the thickened ore slurry to obtain second magnetic minerals and second non-magnetic minerals, wherein the second magnetic minerals are mainly used for recovering lithium concentrate, and the second non-magnetic minerals are mainly used for recovering feldspar products. In the present application, by performing second magnetic separation treatment on the thickened ore slurry, the separation of the second magnetic minerals is effectively promoted, which is beneficial to improve the whiteness of the feldspar products separated from the second non-magnetic minerals. Further, the second magnetic separation treatment can be performed by using a high-gradient magnetic separator, and the magnetic field strength can be 1.3-1.5T, thereby improving the enrichment degree of metallic lithium in the second magnetic minerals and further improving the lithium grade in the second magnetic minerals. For example, in combination with the recovery process of the present application, the lithium grade of the second magnetic minerals can be increased to about 0.7% or even higher. At the same time, due to the low content of slurry in the second magnetic minerals, the second magnetic minerals can be supplied to the flotation treatment in step S500, which can effectively improve the flotation amount in the flotation treatment process, thereby further improving the recovery rate of lithium concentrate. In addition, the cooling water in the high-gradient magnetic separation can also be used for preparing flotation reagents, which can not only improve the flotation effect of the reagents, but also simplify the equipment configuration and reduce the energy consumption.

[0064] (c): the first dewatering treatment is performed on the non-magnetic minerals to obtain a product containing feldspar, wherein the first dewatering treatment can include a thickening treatment and a filter pressing treatment performed in sequence, the mineral concentration of the filter pressing treatment can be improved through the thickening treatment, thereby reducing the number of filter pressing equipment and improving the filter pressing efficiency, and the water content of the dewatering product can also be effectively reduced, which is not only beneficial to reduce the transportation pressure, but also can reduce the drying cost of smelting the dewatering product, in addition, the ore slurry obtained through the filter pressing treatment can be returned to the first dewatering treatment again, thereby further improving the recovery rate of feldspar.

[0065] S500: performing a flotation treatment on the ore sand to obtain a lithium concentrate

[0066] According to the embodiments of the present application, by performing a flotation treatment on the ore sand, a lithium concentrate with a higher grade can be extracted from ore sand with a lower grade, specifically, in combination with Fig. 2 It is understood that the flotation treatment on the ore sand can specifically include:

[0067] (A): performing a roughing treatment on the ore sand to obtain a roughing concentrate and a roughing tailing;

[0068] (B): performing a first cleaning treatment on the roughing concentrate to obtain a first concentrate and a first cleaning tailing, wherein the first cleaning tailing can be preferably returned to step (A) to perform a roughing treatment again;

[0069] (C): performing a second cleaning treatment on the first concentrate to obtain a second concentrate and a second cleaning tailing, wherein the second cleaning tailing can be preferably returned to step (B) to perform a first cleaning treatment again;

[0070] (D): performing a first scavenging treatment on the roughing tailing to obtain a first scavenging concentrate and a first scavenging tailing, wherein the first scavenging concentrate can be preferably returned to step (A) to perform a roughing treatment;

[0071] (E): performing a second scavenging treatment on the first scavenging tailing to obtain a second scavenging concentrate and a second scavenging tailing, wherein the second scavenging concentrate can be preferably returned to step (D) to perform a first scavenging treatment again;

[0072] (F): performing a second dewatering treatment on the second concentrate to obtain a lithium concentrate.

[0073] The lithium concentrate grade and the lithium concentrate recovery rate can be effectively improved by at least once roughing, twice cleaning and twice scavenging of the ore sand, and the first cleaning tailings, the second cleaning tailings, the first scavenging concentrate and the second scavenging concentrate are returned to roughing, cleaning or scavenging again, which is beneficial to further resource utilization of the lithium-containing ore. In addition, it should be noted that the second dehydration treatment can include the thickening treatment and the filter pressing treatment in sequence, and the advantages of the two-stage dehydration process have been described in detail in the foregoing, which will not be repeated here. In general, the water content of the dehydration product can be effectively reduced, and the production cost can be reduced.

[0074] According to the embodiments of the present application, the flotation process is combined with Fig. 2 It is understood that the flotation treatment of the ore sand can specifically include:

[0075] (G): the second scavenging tailings are subjected to third magnetic separation treatment to obtain third magnetic minerals and third non-magnetic minerals, and the third magnetic minerals are returned to the step S100 for re-grinding treatment. In the present application, the second scavenging tailings are subjected to third magnetic separation treatment, and the third magnetic minerals are separated out, which is beneficial to improve the whiteness of the feldspar product. Further, the third magnetic separation treatment can be performed by using a high-gradient magnetic separator, and the magnetic field strength can be 1.3-1.5T. Thus, the mineral intergrowth that is not completely dissociated in the second scavenging tailings can be separated out, and the content of the mineral intergrowth that is not completely dissociated in the third magnetic minerals can be improved. By re-grinding the third magnetic minerals, the single dissociation degree of the useful minerals in the lithium-containing ore can be improved, and thus the lithium concentrate and the useful mineral recovery rate can be further improved. In addition, it should be noted that the third magnetic minerals can be returned to the step (v) for classification treatment. Thus, not only the complete dissociation of the useful minerals can be achieved, but also the production efficiency can be improved and the third magnetic minerals can be prevented from being overground.

[0076] (H): the third non-magnetic minerals are subjected to third dehydration treatment to obtain a feldspar-containing product, wherein the third dehydration treatment can include thickening treatment and filter pressing treatment in sequence. The advantages of the two-stage dehydration process have been described in detail in the foregoing, which will not be repeated here. In general, the water content of the dehydration product can be effectively reduced, and the treatment cost can be reduced.

[0077] According to the embodiments of the present application, the flotation process can select a traditional collector or preferably use a new type of high-efficiency composite flotation reagent. Thus, the problems of poor selectivity, sensitivity to slime and relatively low concentrate grade of a single amine collector can be avoided, and the corrosion of strong acid to equipment can be avoided. It should be noted that the specific type of the composite flotation reagent is not particularly limited in the present application, and a person skilled in the art can select it flexibly according to the actual situation, for example, various commercially available composite flotation reagents can be selected.

[0078] According to the embodiment of the present application, the specific type of lithium-containing ore is not particularly limited, and a person skilled in the art can select it flexibly according to the actual situation. For example, it can include at least one of lepidolite, iron lepidolite and lithium-dolomite, thereby also achieving the recovery of valuable metals such as tin, tantalum and niobium in the lithium-containing ore, obtaining a gravity non-lithium concentrate containing valuable metals such as tin, tantalum and niobium, and combining the recovery process of the present application, the content of tantalum in the gravity non-lithium concentrate containing tin, tantalum and niobium can reach 5-10% or even higher, thereby achieving the full recovery and utilization of useful resources in the lithium-containing ore. In addition, the grade of the lithium-containing ore in the present application is not particularly limited, and a person skilled in the art can also select it flexibly according to the actual situation. For example, both lithium-containing ores with high lithium grade and lithium-poor ores with low lithium grade and / or small embedded particle size of useful minerals can be selected. Specifically, the lithium-containing ore can satisfy at least one of the following conditions: the raw ore grade of the lithium-containing ore can be not more than 0.4% (for example, not more than 0.3%, 0.2% or the like) in terms of Li2O, the pure ore theoretical grade in the lithium-containing ore can be not higher than 1.9% (for example, not higher than 1.8%, 1.7%, 1.6% or 1.5% or the like), and the embedded particle size of useful minerals in the lithium-containing ore can be not more than 0.3mm (for example, not more than 0.25mm, 0.2mm or the like), thereby being more conducive to the development and utilization of ultra-low grade lithium ore resources, activating the "stale ore" with high beneficiation difficulty, solving the problems of low recovery rate, high recovery difficulty and difficult to realize resource utilization of ultra-low grade lithium ore, and being able to convert resource advantage into economic advantage.

[0079] In summary, the method for recovering lithium concentrate from lithium-containing ore according to the above embodiment of the present application can have the following beneficial effects:

[0080] (1) The SABC crushing and grinding system is used in large lithium-dolomite ore and other lithium-containing ores. Compared with the conventional crushing and grinding process (old three-stage crushing + ball milling), the process is simple, the problems of medium and fine crushing equipment blockage are solved, the degree of automation is high, the dust is less, the operation environment is good, the treatment capacity is large, and the process is smooth and stable. In addition, by introducing a hard stone crusher to crush hard-to-grind gravel, the accumulation of hard-to-grind gravel in the semi-autogenous mill is eliminated, and the grinding mill efficiency is fully utilized. At the same time, a bypass is provided at the hard stone bin to realize flexible switching between the SABC process and the SAB process according to the change of hard stone yield, thereby enhancing the adaptability of the process;

[0081] (2) The magnetic arc deironing system can be set to reduce the wear of the slag slurry pump, the cyclone overflow member and the conveying pipeline caused by the crushing steel ball, and ensure the smoothness of the crushing and grinding system;

[0082] (3) The non-lithium concentrate is recovered by adopting the cloth chute treatment + shaking table treatment, which can not only improve the enrichment ratio, but also reduce the ore amount entering the shaking table, thereby reducing the number of shaking tables and the labor intensity of workers; meanwhile, by additionally arranging a thickener before the shaking table, the concentration of the shaking table is ensured, the tailings running water phenomenon of the shaking table operation is avoided, the loss of fine ore concentrate from the tailings end of the shaking table is reduced as much as possible, and the recovery rate of the heavy non-lithium concentrate is improved;

[0083] (4) The new long-cone cyclone group can be used to carry out desliming treatment on the gravity separation tailings, which can not only improve the classification efficiency, improve the sand inclusion and overflow coarse running phenomenon, reduce the loss of useful minerals caused by overflow coarse running, but also create favorable conditions for the flotation operation, avoid the interference of muddy materials on the flotation, and improve the recovery rate of the flotation operation;

[0084] (5) The dewatering treatment can adopt the two-stage dewatering process of thickening + pressure filtration, compared with the original one-stage filtration dewatering process, the concentration of the pressure filtration operation is improved, the pressure filtration efficiency is improved, and the number of pressure filtration devices is reduced; at the same time, the moisture content of the filter cake is reduced, which not only reduces the transportation pressure, but also reduces the drying cost of the downstream smelting;

[0085] (6) The high-gradient high-intensity magnetic separation treatment of the concentrated slurry can improve the whiteness of the superfine feldspar product, and for the low-grade lithium-containing ore, the lithium content of the second magnetic mineral can be enriched to about 0.7% or even higher, and the muddy content of the material is small, which can improve the flotation amount when returning to the flotation process, thereby maximizing the recovery rate of the lithium concentrate;

[0086] (7) The second scavenging tailings can be subjected to high-gradient high-intensity magnetic separation treatment, and the magnetic mineral is returned to the step S100 for re-grinding treatment, which can not only improve the whiteness of the feldspar product, but also return the uncompletely dissociated intergrowth to the re-grinding, so as to improve the monomer dissociation degree of the useful mineral as much as possible, and further improve the recovery rate of the useful mineral and the lithium concentrate;

[0087] (8) The production process is simple, the production cost is low, and the recovery rate of the lithium-containing ore (especially the ultra-low-grade lithium-containing ore) and the grade of the lithium concentrate (for example, for the lithium-containing ore with an ore grade (calculated in terms of Li2O) of not more than 0.4%, a pure ore theoretical grade (calculated in terms of Li2O) of not higher than 1.9%, and a useful mineral embedded particle size of not more than 0.3mm, the recovery rate of the lithium concentrate obtained by adopting the recovery process of the present application can be about 70% or even higher, and the grade of the lithium concentrate obtained can be about 1.7%), which can effectively enhance the resource comprehensive utilization rate and the risk resistance and response ability, activate the "stale ore" with high beneficiation difficulty, realize the full resource utilization of the low-grade lithium-containing ore, and convert the resource advantage into the economic advantage;

[0088] (9) The process flow is suitable for a wide range of applications, and can be applied to the treatment of different mineral species of mica-containing lithium minerals (including lepidolite, iron lepidolite, and lithium muscovite, and other mica ores) and ores with lower lithium content (e.g., the grade can be not greater than 0.2%, 0.3%, or 0.4% in terms of Li2O) and large fluctuations.

[0089] Embodiments of the present application are described in detail below. The embodiments described below are exemplary only, and are intended to explain the present application, and are not to be understood as limiting the present application. In the embodiments, specific techniques or conditions not described are performed according to techniques or conditions described in the literature in the field or according to product instructions. Reagents or instruments not described by manufacturer are all conventional products available on the market.

[0090] Example 1

[0091] (1) The crude ore grade is subjected to crushing and grinding treatment: (1-1) the ultra-low grade lithium muscovite ore is first subjected to coarse crushing treatment, and then subjected to semi-autogenous grinding treatment, wherein the crude ore grade is 0.35% in terms of Li2O, and the pure ore theoretical grade is 1.87%; (1-2) the semi-autogenous grinding product is subjected to screening treatment to obtain first screen overs and first screen unders with a particle size of not greater than 4 mm; (1-3) based on the particle size and weathering degree of the first screen overs, the first screen overs are returned to step (1-1) for continued semi-autogenous grinding treatment, or the first screen overs are first supplied to a hard stone crushing device for crushing treatment, and then the crushing product is returned to step (1-1) for continued semi-autogenous grinding treatment; (1-4) the first screen unders are subjected to classification treatment using a cyclone group to obtain material with a particle size of ore particles of not greater than 0.25 mm and material with a particle size of ore particles of greater than 0.25 mm; (1-5) the material with a particle size of ore particles of greater than 0.25 mm is subjected to ball milling treatment, and the ball milling product is returned to step (1-4) for classification treatment, and finally material with a particle size of ore particles of not greater than 0.25 mm is obtained for subsequent treatment.

[0092] (2) The material with a particle size of ore particles of not greater than 0.25 mm is subjected to first magnetic separation treatment, and the magnetic field strength is 3500 Gs, to obtain first magnetic minerals containing iron and the like and first non-magnetic minerals;

[0093] (3) performing gravity separation treatment on the first non-magnetic mineral, and the specific steps are as follows: (3-1) performing apron chute treatment on the first non-magnetic mineral to obtain heavy slurry and light slurry; (3-2) performing first thickening treatment on the heavy slurry to obtain thickened heavy slurry; (3-3) performing first table treatment on the thickened heavy slurry to obtain first table concentrate and first table tailings, and returning the first table tailings to step (3-1) for apron chute treatment again; (3-4) performing second table treatment on the first table concentrate to obtain gravity separation non-lithium concentrate and second table tailings, and returning the second table tailings to step (3-1) for apron chute treatment again, and finally obtaining tantalum-niobium-tin mixed concentrate and gravity separation tailings;

[0094] (4) performing desliming classification treatment on the gravity separation tailings by using a cyclone group to obtain ore sand and slurry with a particle size of not greater than 0.025 mm: (4-1) performing second thickening treatment on the slurry to obtain thickened slurry; (4-2) performing second magnetic separation treatment on the thickened slurry, and the magnetic field strength is 1.5 T, to obtain second magnetic mineral with a lithium grade of 0.7% and second non-magnetic mineral; (4-3) performing first dewatering treatment on the non-magnetic mineral to obtain a product containing feldspar;

[0095] (5) performing flotation treatment on the ore sand: (5-1) performing roughing treatment on the ore sand and the second magnetic mineral to obtain roughing concentrate and roughing tailings; (5-2) performing first cleaning treatment on the roughing concentrate to obtain first concentrate and first cleaning tailings, and returning the first cleaning tailings to step (5-1) for roughing treatment; (5-3) performing second cleaning treatment on the first concentrate to obtain second concentrate and second cleaning tailings, and returning the second cleaning tailings to step (5-2) for first cleaning treatment; (5-4) performing first scavenging treatment on the roughing tailings to obtain first scavenging concentrate and first scavenging tailings, and returning the first scavenging concentrate to step (5-1) for roughing treatment; (5-5) performing second scavenging treatment on the first scavenging tailings to obtain second scavenging concentrate and second scavenging tailings, and returning the second scavenging concentrate to step (5-4) for first scavenging treatment; (5-6) performing second dewatering treatment on the second concentrate to obtain lithium concentrate; (5-7) performing third magnetic separation treatment on the second scavenging tailings, and the magnetic field strength is 1.5 T, to obtain third magnetic mineral and third non-magnetic mineral; (5-8) performing third dewatering treatment on the third non-magnetic mineral to obtain a feldspar product, and returning the third magnetic mineral to step (1) for crushing and grinding treatment.

[0096] By using the above recovery method, the recovery rate of the lithium concentrate obtained is 70%, and the lithium concentrate grade is 1.7% (calculated as Li2O).

[0097] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0098] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method of recovering a lithium concentrate from a lithium-bearing ore, characterised in that, The method comprises: (1) performing a crushing and grinding treatment on the lithium-containing ore by using a SABC crushing and grinding system, so as to obtain material with a particle size of not greater than 0.25 mm; (2) performing a first magnetic separation treatment on the material, so as to obtain first magnetic minerals and first non-magnetic minerals; (3) performing a gravity separation treatment on the first non-magnetic minerals, so as to obtain a gravity separation non-lithium concentrate and a gravity separation tailings, the gravity separation treatment comprising a cloth apron chute treatment and a shaking table treatment performed in sequence; In step (3), the gravity separation treatment comprises: (3-1) performing a cloth apron chute treatment on the first non-magnetic minerals, so as to obtain heavy slurry and light slurry; (3-2) performing a first thickening treatment on the heavy slurry, so as to obtain thickened heavy slurry; (3-3) performing a first shaking table treatment on the thickened heavy slurry, so as to obtain first shaking table concentrate and first shaking table tailings; (3-4) performing a second shaking table treatment on the first shaking table concentrate, so as to obtain the gravity separation non-lithium concentrate and second shaking table tailings; (4) performing a desliming classification treatment on the gravity separation tailings, so as to obtain ore sand and ore slime; wherein step (4) further comprises: (4-1) performing a second thickening treatment on the ore slime, so as to obtain thickened ore slime; (4-2) performing a second magnetic separation treatment on the thickened ore slime, so as to obtain second magnetic minerals and second non-magnetic minerals; (4-3) performing a first dewatering treatment on the non-magnetic minerals, so as to obtain a product containing feldspar, Optionally, the particle size of the ore slime is not greater than 0.025 mm; Optionally, in step (4-2), the magnetic field strength of the second magnetic separation is 1.3-1.5 T; Optionally, in step (4-2), the second magnetic minerals are supplied to step (5) for a flotation treatment; Optionally, in step (4), the gravity separation tailings are subjected to a cyclone desliming classification treatment by using a cyclone group, so as to obtain the ore sand and the ore slime; 2. The method of claim 1, wherein, (5) performing a flotation treatment on the ore sand, so as to obtain a lithium concentrate. In step (1), the crushing and grinding treatment comprises: (1-1) performing a semi-autogenous grinding treatment on the lithium-containing ore; (1-2) performing a screening treatment on the semi-autogenous grinding product, so as to obtain first oversize and first undersize; (1-3) based on the particle size and weathering degree of the first oversize, selecting to return the first oversize to step (1-1) for continuing the semi-autogenous grinding treatment, or first supplying the first oversize to a hard stone crushing device for a crushing and grinding treatment, and then returning the crushing product to step (1-1) for continuing the semi-autogenous grinding treatment; (1-4) performing a classification treatment on the first undersize by using a cyclone group, so as to obtain material with a particle size of not greater than 0.25 mm and material with a particle size of greater than 0.25 mm; (1-5) performing a ball milling treatment on the material with a particle size of greater than 0.25 mm, and returning the ball milling product to step (1-4) for the classification treatment, Optionally, in step (1-1), the lithium-containing ore is subjected to a coarse crushing treatment before the semi-autogenous grinding treatment; Optionally, in step (1-2), the particle size of the first undersize is not greater than 4 mm.

3. The method of claim 1, wherein, In step (2), the magnetic field strength of the first magnetic separation is 3000-4000Gs.

4. The method according to any one of claims 1-3, characterized in that, Optionally, in step (3-3), the first table tailings are returned to step (3-1) for the blanket chute treatment. Optionally, in step (3-4), the second table tailings are returned to step (3-1) for the blanket chute treatment.

5. The method of claim 1, wherein, In step (5), the flotation treatment comprises: (5-1) performing a roughing treatment on the ore sand to obtain a roughing concentrate and a roughing tailings; (5-2) performing a first cleaning treatment on the roughing concentrate to obtain a first concentrate and a first cleaning tailings; (5-3) performing a second cleaning treatment on the first concentrate to obtain a second concentrate and a second cleaning tailings; (5-4) performing a first scavenging treatment on the roughing tailings to obtain a first scavenging concentrate and a first scavenging tailings; (5-5) performing a second scavenging treatment on the first scavenging tailings to obtain a second scavenging concentrate and a second scavenging tailings; (5-6) performing a second dewatering treatment on the second concentrate to obtain the lithium concentrate.

6. The method of claim 5, wherein, Step (5) further comprises: (5-7) performing a third magnetic separation treatment on the second scavenging tailings to obtain a third magnetic mineral and a third non-magnetic mineral; (5-8) performing a third dewatering treatment on the third non-magnetic mineral to obtain a product containing feldspar.

7. The method of claim 6, wherein, At least one of the following conditions is met: In step (5-2), the first cleaning tailings are returned to step (5-1) for the roughing treatment; In step (5-3), the second cleaning tailings are returned to step (5-2) for the first cleaning treatment; In step (5-4), the first scavenging concentrate is returned to step (5-1) for the roughing treatment; In step (5-5), the second scavenging concentrate is returned to step (5-4) for the first scavenging treatment; In step (5-7), the magnetic field strength of the third magnetic separation treatment is 1.3-1.5T; In step (5-8), the third magnetic mineral is returned to step (1) for the crushing and grinding treatment.

8. The method of claim 1 or 7, wherein, The lithium-containing ore comprises at least one of lepidolite, eisenlepidolite and lithia muscovite; Optionally, the raw ore grade of the lithium-containing ore is not more than 0.4% in terms of Li2O; Optionally, the pure ore theoretical grade of the lithium-containing ore is not higher than 1.9% in terms of Li2O; Optionally, the dissemination size of the useful minerals in the lithium-containing ore is not higher than 0.3mm in terms of Li2O.

9. The method of claim 8, wherein, The gravity non-lithium concentrate is a tantalum-tin mixed concentrate, and the content of tantalum in the tantalum-tin mixed concentrate is 5-10%.

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