Beneficiation method for recovering low-grade lepidolite from tailings pond

Abstract

The application provides a beneficiation method for recovering low-grade lepidolite from a tailings pond. The method comprises: configuring a dry ore sample in the tailings pond into an ore slurry, performing scrubbing and desorption by grinding, and obtaining a grinding product; adjusting the grinding product to a predetermined mass concentration, and then performing desulfurization flotation to obtain a sulfide concentrate and a desulfurized tailings; fully stirring the desulfurized tailings, and then performing sedimentation desliming to obtain a desliming concentrate and a desliming tailings; adding a predetermined reagent to the desliming tailings to perform lepidolite direct flotation, and through roughing, cleaning and scavenging, a lepidolite concentrate and tailings are obtained. Through the above method, the adverse effects of sulfide minerals and ore slurry are effectively reduced by using the scrubbing and desorption-activation desulfurization-sedimentation desliming-flotation process, and the desliming efficiency is improved, so that the low-grade lepidolite is recovered from the tailings pond in a simple and efficient manner. In the flotation process, the use of efficient conditioning agents and collectors can further strengthen the collection effect and improve the recovery rate.

Description

Technical Field

[0001] This invention relates to the field of lithium ore beneficiation technology, and in particular to a beneficiation method for recovering low-grade lepidolite from tailings ponds. Background Technology

[0002] With the rapid development of the new energy electric vehicle industry, the consumption of lithium resources has been increasing year by year. Lithium carbonate extracted from lepidolite (Li2O) ore through enrichment and smelting is an important raw material for the new energy battery industry. my country has relatively abundant resources in this area, mainly distributed in Sichuan, Jiangxi, Hunan, and Xinjiang. These regions contain various rare metals such as lithium, tantalum, niobium, rubidium, and cesium, as well as non-ferrous polymetallic metals such as copper, zinc, and lead, and various non-metallic minerals such as feldspar and quartz. However, due to limitations in early beneficiation techniques, tailings ponds in these mines still contain tailings rich in lepidolite, with an average Li2O grade of 0.2% to 1.0%, possessing good development and utilization value. It is worth noting, however, that this type of ore belongs to the flotation process tailings. Lepidolite minerals often exhibit problems such as fine particle size, complex intergrowth relationships, high gangue mudification, and high residual concentration of beneficiation reagents. Furthermore, it may contain arsenopyrite, pyrite, reverse flotation fine mud, and carbonaceous matter incorporated into the tailings. Therefore, how to develop tailings lithium resources in a reasonable, safe and efficient manner will be a major challenge and key point in subsequent lithium ore beneficiation.

[0003] In the prior art, patent CN115155796A discloses a combined flotation and magnetic separation method for recovering fine-grained lepidolite from tailings. This method employs a separation process involving direct slurry preparation, strong stirring, roughing with a flotation column, cleaning with a flotation column, and high-gradient magnetic separation. While it can recover fine-grained lepidolite resources from tailings, the process is complex and the recovery rate is low. Furthermore, traditional lepidolite flotation processes typically use strong acid to prepare the slurry, which causes significant corrosion to equipment and incurs high costs for reagent transportation and storage.

[0004] In view of this, it is necessary to design an improved beneficiation method for recovering low-grade lepidolite from tailings ponds in order to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention aims to provide a beneficiation method for recovering low-grade lepidolite from tailings ponds. This invention employs a scrubbing and de-reagenting-activation desulfurization-sedimentation desliming-flotation process, and utilizes highly efficient modifiers and collectors during flotation, effectively achieving efficient flotation recovery of low-grade fine-grained lepidolite from tailings ponds.

[0006] To achieve the above objectives, the present invention provides a beneficiation method for recovering low-grade lepidolite from tailings ponds, comprising the following steps: S1. Prepare a slurry from the dry ore sample in the tailings pond, and then wash and remove reagents through grinding to obtain the grinding product; S2. Adjust the grinding product to a predetermined mass concentration, and then perform desulfurization flotation to obtain sulfide concentrate and desulfurization tailings; S3. After thoroughly stirring the desulfurization tailings, allow them to settle and deslim to obtain deslimed concentrate and deslimed tailings. S4. Add a predetermined reagent to the deslimed tailings to perform lepidolite positive flotation roughing to obtain lepidolite roughing froth and lepidolite roughing underflow. S5. The lepidolite roughing froth is finely treated to obtain lepidolite concentrate; the lepidolite roughing underflow is scavenged to obtain tailings.

[0007] As a further improvement of the present invention, in step S4, the predetermined reagents include 2500~4000 g / t of sodium carbonate, 400~600 g / t of water glass, 80~150 g / t of modifier and 500~750 g / t of collector.

[0008] As a further improvement of the present invention, the modifier comprises the following components by weight percentage: Aluminum sulfate: 30%~40%; Copper sulfate: 5%~10%; Ethylenediamine phosphate: 30%~40%; Sulfonated polyacrylamide: 10%~20%.

[0009] The collector comprises the following components: Coconut oil amine: 10%~20%; Tetradecyltrimethylammonium bromide: 20%~30%; Sodium dodecylbenzenesulfonate: 20%~30%; Oxidized paraffin soap: 30%~40%.

[0010] As a further improvement of the present invention, in step S2, the desulfurization flotation includes a primary desulfurization roughing, a primary desulfurization cleaning, and a primary desulfurization scavenging; the middlings obtained from the desulfurization cleaning and the desulfurization scavenging are returned to the desulfurization roughing operation.

[0011] As a further improvement of the present invention, the desulfurization roughing agent includes 400-600 g / t of citric acid, 40-60 g / t of copper sulfate, 80-120 g / t of butyl xanthate, and 12-16 g / t of 2 # Oil; the desulfurization scavenging agents include 40-60 g / t butyl xanthate and 12-16 g / t 2 # Oil.

[0012] As a further improvement of the present invention, in step S3, the stirring speed is 400~600 r / min; the settling time of the sedimentation and desliming is 4~6 min, the desliming yield is 8%~13%, and the loss rate of Li2O after sedimentation and desliming is 10%~15%.

[0013] As a further improvement of the present invention, in step S5, the refining process is performed three times. The reagent used for the first refining is 300-500 g / t of water glass, the reagent used for the second refining is 150-250 g / t of water glass, and the reagent used for the third refining is 80-120 g / t of water glass. The middlings obtained from the first refining are returned to the sedimentation and desliming operation in step S3, the middlings obtained from the second refining are returned to the first refining operation, and the middlings obtained from the third refining are returned to the second refining operation.

[0014] As a further improvement of the present invention, in step S5, the scavenging is performed twice. The agent used in the first scavenging is 150~250g / t of the collector, and the agent used in the second scavenging is 80~120g / t of the collector. The middlings obtained from the first scavenging are returned to the sedimentation and desliming operation in step S3, and the middlings obtained from the second scavenging are returned to the first scavenging.

[0015] As a further improvement of the present invention, in step S1, the mass concentration of the ore sample in the slurry is 60%~65%; and the mass percentage of ore with a particle size of less than 0.074mm in the grinding product is 51%~53%.

[0016] As a further improvement of the present invention, in step S2, the predetermined mass concentration is 30% to 35%.

[0017] The beneficial effects of this invention are: The present invention provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. By employing a scrubbing and de-reagenting-activation desulfurization-sedimentation desliming-flotation process, it ensures the maximum removal of sulfide minerals from the ore sample while preventing further mudification during wet grinding, significantly reducing the adverse effects of slime. Furthermore, due to the high content of fine-grained minerals in the tailings pond samples, the sedimentation desliming method used in this invention is simpler, requires less equipment, occupies less space, and achieves higher desliming efficiency compared to traditional flotation desliming methods. In addition, this invention employs an acid-free process in the lepidolite flotation process, eliminating the use of strong acid slurry conditioning, and using highly efficient modifiers and collectors to enhance the collection of fine-grained lepidolite ore, further improving the Li₂O recovery rate. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the mineral processing flow for the mineral processing method of recovering low-grade lithium mica from tailings ponds, provided by the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0021] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0022] This invention provides a mineral processing method for recovering low-grade lepidolite from tailings ponds, the process flow diagram of which is shown below. Figure 1 As shown, it includes the following steps: S1. Prepare a slurry from the dry ore sample in the tailings pond, and then wash and remove reagents through grinding to obtain the grinding product; S2. Adjust the grinding product to a predetermined mass concentration, and then perform desulfurization flotation to obtain sulfide concentrate and desulfurization tailings; S3. After thoroughly stirring the desulfurization tailings, allow them to settle and deslim to obtain deslimed concentrate and deslimed tailings. S4. Add a predetermined reagent to the deslimed tailings to perform lepidolite positive flotation roughing to obtain lepidolite roughing froth and lepidolite roughing underflow. S5. The lepidolite roughing froth is finely treated to obtain lepidolite concentrate; the lepidolite roughing underflow is scavenged to obtain tailings.

[0023] Specifically, in step S1, a slurry is prepared by adding water to the ore sample, and preferably the mass concentration of the ore sample in the slurry is 60% to 65%; when the ore is washed and de-treated by grinding, preferably the mass percentage of ore with a particle size of less than 0.074 mm in the grinding product is 51% to 53%.

[0024] In step S2, the mass concentration is adjusted to a predetermined mass concentration by adding water to dilute the grinding product, and preferably the predetermined mass concentration is 30% to 35%.

[0025] Based on this, the desulfurization flotation includes primary desulfurization roughing, primary desulfurization cleaning, and primary desulfurization scavenging.

[0026] The desulfurization roughing agents include 400-600 g / t citric acid, 40-60 g / t copper sulfate, 80-120 g / t butyl xanthate, and 12-16 g / t 2... # Oil is desulfurized and roughed to obtain desulfurized rougher concentrate and desulfurized rougher underflow. When the desulfurized rougher concentrate is further desulfurized and refined, no reagents are added to obtain sulfide concentrate and refined middlings, which are then returned to the desulfurization rougher operation. When the desulfurized rougher underflow is subjected to desulfurization scavenging, the added reagents include 40-60 g / t of butyl xanthate and 12-16 g / t of 2... # After desulfurization and scavenging, the oil yields desulfurized tailings and desulfurized scavenged ore. The desulfurized scavenged ore is then returned to the desulfurization roughing operation.

[0027] By employing the aforementioned scrubbing and desulfurization processes, sulfide minerals in the ore sample can be removed as much as possible, while further mudification during wet grinding is avoided, greatly reducing the adverse effects of slime. Furthermore, given the high content of fine-grained minerals in the tailings pond samples, this invention uses sedimentation desliming. Compared to traditional flotation desliming methods, this approach is not only simpler, requires less equipment, and occupies less space, but also achieves higher desliming efficiency.

[0028] Specifically, in step S3, when stirring the desulfurization tailings, the preferred stirring speed is 400-600 r / min; after stopping stirring, allow it to stand for 4-6 minutes for settling and desliming. During the settling process, mineral particles settle freely under the combined action of gravity, drag, and buoyancy. The mineral particles form layers according to their particle size and density, resulting in a gradual increase in particle size and density from top to bottom in the settled slurry layer. The finer particles in the upper layer are discharged by siphoning, yielding deslimed concentrate and deslimed tailings. Under the above conditions, the desliming yield is 8%-13%, and the loss rate of Li2O after settling and desliming can be controlled within 10%-15%.

[0029] In step S4, the predetermined reagents include 2500-4000 g / t of sodium carbonate, 400-600 g / t of water glass, 80-150 g / t of modifier, and 500-750 g / t of collector. During the flotation process in this step, the stirring time after adding the modifier is 2-3 minutes, and the stirring time after adding the collector is 2-3 minutes.

[0030] The modifier comprises the following components by weight percentage: Aluminum sulfate: 30%~40%; Copper sulfate: 5%~10%; Ethylenediamine phosphate: 30%~40%; Sulfonated polyacrylamide: 10%~20%.

[0031] Using this modifier in the lepidolite flotation process allows the weakly acidic aluminum sulfate to effectively clean the surface of the lepidolite mineral covered by fine mud. On this basis, copper sulfate activates the small amount of sulfide minerals in the mineral, while improving the overall flotation rate. Furthermore, ethylenediamine phosphate and sulfonated polyacrylamide can, to some extent, eliminate the influence of mud on lepidolite flotation, help activate lepidolite, stabilize flotation foam, reduce collector consumption, and selectively flocculate fine-grained silicate minerals such as quartz, reducing the interference of muddy gangue on flotation.

[0032] The collector comprises the following components by weight percentage: Coconut oil amine: 10%~20%; Tetradecyltrimethylammonium bromide: 20%~30%; Sodium dodecylbenzenesulfonate: 20%~30%; Oxidized paraffin soap: 30%~40%.

[0033] When this collector is used in the flotation process of lepidolite, the cocoagulant and paraffin soap in the collector components can enhance the collection ability of lepidolite minerals through the synergistic effect between the anionic and cationic collectors, and also have a certain degree of selectivity. Tetradecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate, as auxiliary collectors, can enhance the collection ability and selectivity of fine-grained lepidolite, and have a certain degree of foaming properties, which can stabilize the foam layer and prevent fine-grained lepidolite from falling off.

[0034] In step S5, the refining process is performed three times. The first refining uses 300-500 g / t of water glass as the reagent. After the first refining, concentrate I and middlings I are obtained. Concentrate I enters the second refining operation, while middlings I is returned to the settling and desliming operation in step S3. This operation avoids the problem of increased circulating load caused by returning middlings I to the roughing process, thus preventing any impact on the lithium concentrate grade. Furthermore, returning middlings I to the settling and desliming operation removes fine mud from the middlings, eliminating interference, reducing the feed rate, and ensuring that the lithium recovery rate is minimized.

[0035] The second refining process uses 150-250 g / t of water glass as the reagent. After the second refining, concentrate II and middlings II are obtained. Middlings II is returned to the first refining operation, while concentrate II enters the third refining operation. The third refining process uses 80-120 g / t of water glass as the reagent. After the third refining, lepidolite concentrate and middlings III are obtained. Middlings III is returned to the second refining operation.

[0036] The scavenging process is performed twice. The first scavenging uses 150-250 g / t of the collector. After the first scavenging, tailings I and scavenged concentrate I are obtained. Scavenged concentrate I is returned to the settling and desliming operation in step S3, while tailings I enter the second scavenging operation. The second scavenging uses 80-120 g / t of the collector. After the second scavenging, tailings and scavenged concentrate II are obtained. Scavenged concentrate II is returned to the first scavenging operation, and the tailings are combined with the deslimed concentrate obtained in step S3 to become the final tailings.

[0037] Based on the above beneficiation method, it is possible to effectively achieve efficient flotation recovery of low-grade fine-grained lepidolite in tailings ponds, and the final lepidolite concentrate has a Li2O content of more than 1.5% and a recovery rate of more than 52%, achieving a high grade and recovery rate.

[0038] The following describes in detail the beneficiation method for recovering low-grade lithium mica from tailings ponds provided by the present invention, with reference to specific embodiments and comparative examples.

[0039] Example 1 The mineral sample used in this embodiment comes from a tailings dam in China. The proportion of particles smaller than 0.074 mm in the ore is 47%~49%, and the proportion of particles smaller than 0.023 mm is 23%~25%. The lithium in the mineral sample exists in the form of lepidolite. The content of Li2O in the mineral sample is 0.34%, the content of arsenopyrite is 9.08%, the content of pyrite and pyrrhotite is 5.79%, the content of feldspar is 10.36%, the content of chlorite is 2.85%, and the content of quartz is 32.05%.

[0040] Based on the above-mentioned ore sample, this embodiment provides a beneficiation method for recovering low-grade lepidolite from tailings ponds, specifically including the following steps: S1. The above ore sample was mixed with water to prepare a slurry with a mass concentration of 65%. The slurry was then washed and de-treated using a mill. The mass percentage of ore with a particle size of less than 0.074 mm in the resulting grinding product was approximately 52%.

[0041] S2. Add water to the ground product and adjust its concentration to 35%, then carry out desulfurization flotation.

[0042] The desulfurization flotation process includes: First, add 500g / t of citric acid, 50g / t of copper sulfate, 100g / t of butyl xanthate and 14g / t of No. 2 oil for desulfurization roughing to obtain desulfurized roughing concentrate and desulfurized roughing underflow.

[0043] The desulfurized rough concentrate is subjected to a desulfurization and cleaning process without the addition of reagents, resulting in sulfide concentrate and desulfurized middlings. The desulfurized middlings are then returned to the desulfurization roughing operation.

[0044] The desulfurization roughing underflow is subjected to a first desulfurization scavenging process, with the added reagents being 50 g / t butyl xanthate and 14 g / t 2... # After desulfurization and scavenging, the oil yields desulfurized tailings and desulfurized scavenged ore. The desulfurized scavenged ore is then returned to the desulfurization roughing operation.

[0045] S3. The desulfurization tailings are poured into the desliming equipment and thoroughly stirred at a stirring speed of 500 r / min. After standing for 5 minutes, the slurry layer undergoes sedimentation and desliming. The particle size and density of the slurry layer gradually increase from top to bottom. The fine minerals in the upper layer are discharged by siphon discharge. The discharged portion is the deslimed concentrate, and the remaining portion is the deslimed tailings. In this embodiment, the desliming yield of this sedimentation and desliming process is approximately 10%, and the Li2O loss rate is approximately 12%.

[0046] S4. A modifier is prepared by mixing aluminum sulfate, copper sulfate, ethylenediamine phosphate, and sulfonated polyacrylamide in a mass percentage ratio of 40%:5%:40%:15%. A collector is prepared by mixing cocoylamine, tetradecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, and oxidized paraffin soap in a mass percentage ratio of 15%:25%:25%:35%. 2500 g / t of sodium carbonate, 500 g / t of water glass, 80 g / t of the above modifier, and 500 g / t of the above collector are added sequentially to the deslimed tailings. After adding the modifier and collector, the mixture is stirred for 2 minutes each, and then subjected to lepidolite positive flotation roughing to obtain lepidolite roughing froth and lepidolite roughing underflow.

[0047] S5. Perform three cleaning processes on the lepidolite roughing foam: The first cleaning process uses 400 g / t water glass as the reagent, and after the first cleaning process, concentrate I and middlings I are obtained. Middlings I is returned to the settling and desliming operation in step S3, while concentrate I enters the second cleaning operation; The second cleaning process uses 200 g / t water glass as the reagent, and after the second cleaning process, concentrate II and middlings II are obtained. Middlings II is returned to the first cleaning operation, while concentrate II enters the third cleaning operation; The third cleaning process uses 100 g / t water glass as the reagent, and after the third cleaning process, lepidolite concentrate and middlings III are obtained. Middlings III is returned to the second cleaning operation.

[0048] The lepidolite roughing underflow is subjected to two scavenging processes: the first scavenging uses 200 g / t of the aforementioned collector, and after the first scavenging, tailings I and scavenged concentrate I are obtained. Scavenged concentrate I is returned to the settling and desliming operation in step S3, while tailings I enter the second scavenging operation; the second scavenging uses 100 g / t of the aforementioned collector, and after the second scavenging, tailings and scavenged concentrate II are obtained. Scavenged concentrate II is returned to the first scavenging operation, and the tailings are combined with the desliming concentrate obtained in step S3 to become the final tailings.

[0049] Using the above method, this embodiment obtained 1.58% Li2O in lepidolite concentrate with a recovery rate of 54.15%.

[0050] Example 2 This embodiment provides a mineral processing method for recovering low-grade lithium mica from tailings ponds. The ore sample source used is the same as that in Example 1. The only difference between Example 1 and Example 2 is that the amount of sodium carbonate added in step S4 is changed to 4000 g / t. The remaining steps and parameters are the same as those in Example 1 and will not be repeated here.

[0051] In this embodiment, a lithium mica concentrate containing 1.52% Li2O was obtained, with a recovery rate of 55.13%.

[0052] Example 3 This embodiment provides a mineral processing method for recovering low-grade lithium mica from tailings ponds. The source of the ore sample used is the same as that in Example 1. The only difference between Example 1 and Example 2 is that the amount of the adjusting agent added in step S4 is changed to 150 g / t. The remaining steps and parameters are the same as those in Example 1 and will not be repeated here.

[0053] In this embodiment, a lithium mica concentrate containing 1.60% Li2O was obtained, with a recovery rate of 52.78%.

[0054] Example 4 This embodiment provides a mineral processing method for recovering low-grade lithium mica from tailings ponds. The source of the ore sample used is the same as that in Example 1. The only difference between Example 1 and Example 2 is that the amount of collector added in step S4 is changed to 750 g / t. The remaining steps and parameters are the same as those in Example 1 and will not be repeated here.

[0055] In this embodiment, a lithium mica concentrate containing 1.51% Li2O was obtained, with a recovery rate of 55.64%.

[0056] Comparative Example 1 This comparative example provides a mineral processing method for recovering low-grade lepidolite from tailings ponds. The ore sample source used is the same as that in Example 1. The only difference from Example 1 is that step S3, sedimentation and desliming, is not performed. Instead, lepidolite is directly subjected to positive flotation of the desulfurized tailings. The middlings from the flotation process are returned sequentially. The specific flotation steps and parameters are the same as those in Example 1 and will not be repeated here.

[0057] The comparative example yielded a lithium mica concentrate containing 1.57% Li2O with a recovery rate of 47.75%. Compared with Example 1, the recovery rate was significantly lower, indicating that the present invention can effectively improve the Li2O recovery rate by desliming the desulfurization tailings.

[0058] Comparative Example 2 This comparative example provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore sample source used is the same as in Example 1. The only difference from Example 1 is that step S3, settling and desliming, is changed to flotation and desliming. The reagents used in flotation and desliming are 30 g / t oleic acid and 15 g / t 2... # The oil, and the remaining steps and parameters are the same as in Example 1, and will not be repeated here.

[0059] This comparative example yielded a lithium mica concentrate containing 1.45% Li2O with a recovery rate of 49.58%. Compared with Example 1, it can be seen that the sedimentation desliming method used in this invention can improve the grade and recovery rate of Li2O compared with the traditional flotation desliming method.

[0060] Comparative Example 3 This comparative example provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore sample source used is the same as that in Example 1. The only difference between Example 1 and Example 2 is that no modifier is added in step S4. All other steps and parameters are the same as in Example 1 and will not be repeated here.

[0061] This comparative example yielded a lithium mica concentrate containing 1.42% Li2O with a recovery rate of 45.94%. Compared with Example 1, it can be seen that the present invention can effectively improve the grade and recovery rate of Li2O by adding a modifier of a specific composition during the lithium mica flotation process.

[0062] Comparative Example 4 This comparative example provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore sample source used is the same as in Example 1. The only difference from Example 1 is that the collector in step S4 is replaced with dodecylamine and oxidized paraffin soap 731. The mass percentages of dodecylamine and oxidized paraffin soap 731 in the collector are 20% and 80%, respectively. The remaining steps and parameters are the same as in Example 1 and will not be repeated here.

[0063] The comparative example yielded a lithium mica concentrate containing 1.62% Li2O with a recovery rate of 51.28%. Compared with Example 1, it can be seen that the collector used in this invention can improve the recovery rate of Li2O compared with traditional collectors.

[0064] Comparative Example 5 This comparative example provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore sample source used is the same as in Example 1. The only difference between Example 1 and Example 2 is that in step S4, during the lepidolite positive flotation roughing process, sulfuric acid is added to adjust the pH to 3 according to the traditional lepidolite beneficiation process, and the collector is replaced with dodecylamine. The dosage of the collector is adjusted to 300 g / t. The remaining steps and parameters are the same as in Example 1 and will not be repeated here.

[0065] This comparative example yielded a lithium mica concentrate containing 1.49% Li2O with a recovery rate of 46.27%. Compared with Example 1, it can be seen that, compared with the traditional lithium mica beneficiation process, the method provided by this invention not only eliminates the need for strong acid slurry conditioning, avoiding equipment corrosion and reducing the transportation and storage costs of reagents, but also effectively improves the grade and recovery rate of Li2O.

[0066] Example 5 and Comparative Example 6 Example 5 and Comparative Example 6 respectively provide a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore samples used are from the same sources as in Example 1. The difference between Example 5 and Example 6 lies in the change of the composition of the modifier. The remaining steps and parameters are the same as in Example 1 and will not be repeated here. The mass percentage of each component in the modifier provided in Example 5 and Comparative Example 6 is shown in Table 1.

[0067] Table 1. Mass percentage of each component in the modifier in Example 5 and Comparative Example 6 The mineral processing results of the mineral processing methods provided in Example 5 and Comparative Example 6 are shown in Table 2.

[0068] Table 2. Mineral processing results of Example 5 and Comparative Example 6 As shown in Table 2, the Li₂O grade and recovery rate in the lepidolite concentrate of Comparative Example 6 both decreased. This is because the copper sulfate content in the modifier was as high as 25%, which activated the target mineral and a large amount of gangue minerals. Furthermore, copper ions have a compressive effect on the electric double layer, leading to thin and brittle froth and metal loss. Simultaneously, the aluminum sulfate content decreased, weakening the cleaning effect on the lepidolite surface covered by fine mud, further reducing the total amount of floating metal and affecting flotation indicators. Therefore, the proportions of the modifier components in Comparative Example 6 were unreasonable. This invention, by optimizing the proportions of the components in the modifier, can effectively improve the Li₂O content and Li₂O recovery rate in the lepidolite concentrate.

[0069] Examples 6-7 and Comparative Example 7 Examples 6-7 and Comparative Example 7 respectively provide a beneficiation method for recovering low-grade lepidolite from tailings ponds. The ore samples used are from the same sources as in Example 1. The difference between Example 1 and Example 7 lies in the change of the collector composition; the remaining steps and parameters are the same as in Example 1 and will not be repeated here. The mass percentage of each component in the modifiers provided in Examples 6-7 and Comparative Example 7 is shown in Table 3.

[0070] Table 3. Mass percentage of each component in the modifier in Examples 6-7 and Comparative Example 7 The mineral processing results of the mineral processing methods provided in Examples 6-7 and Comparative Example 7 are shown in Table 4.

[0071] Table 4. Mineral processing results of Examples 6-7 and Comparative Example 7 As shown in Table 4, adjusting the components of the collector within the specified range does not significantly change the Li2O recovery rate of lepidolite concentrate, while the Li2O grade fluctuates with the changes in the proportion of each component. When the proportion of coconut oil amine increases and the proportion of oxidized paraffin soap decreases, and both exceed the specified range, the collector's collecting ability is enhanced, but its selectivity is weakened. The adsorption of muddy gangue by coconut oil amine leads to weak froth and a reduction in the amount of ore carried, affecting the flotation indicators. Therefore, the proportions of the collector components in Comparative Example 7 are unreasonable. This invention, by optimizing the proportions of each component in the collector, can effectively improve the Li2O content and Li2O recovery rate in lepidolite concentrate.

[0072] In summary, this invention provides a beneficiation method for recovering low-grade lepidolite from tailings ponds. The method includes preparing a slurry from a dry ore sample in the tailings pond, grinding and scrubbing to remove reagents, obtaining a grinding product; adjusting the grinding product to a predetermined mass concentration, then performing desulfurization flotation to obtain sulfide concentrate and desulfurized tailings; thoroughly stirring the desulfurized tailings and then settling and desliming to obtain deslimed concentrate and deslimed tailings; adding predetermined reagents to the deslimed tailings for lepidolite positive flotation, and obtaining lepidolite concentrate and tailings through roughing, cleaning, and scavenging. Through this method, this invention effectively reduces the adverse effects of sulfide minerals and slime by utilizing a scrubbing-derelation-activation desulfurization-settling-flotation process, improving desliming efficiency, and thus achieving the recovery of low-grade lepidolite from tailings ponds in a simple and efficient manner. The use of highly efficient modifiers and collectors during the flotation process further enhances the collecting effect and improves the recovery rate.

[0073] The above 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 with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mineral processing method for recovering low-grade lepidolite from tailings ponds, characterized in that, Includes the following steps: S1. Prepare a slurry from the dry ore sample in the tailings pond, and then wash and remove reagents through grinding to obtain the grinding product; S2. Adjust the grinding product to a predetermined mass concentration, and then perform desulfurization flotation to obtain sulfide concentrate and desulfurization tailings; S3. After thoroughly stirring the desulfurization tailings, allow them to settle and deslim to obtain deslimed concentrate and deslimed tailings. S4. Add a predetermined reagent to the deslimed tailings to perform lepidolite positive flotation roughing to obtain lepidolite roughing froth and lepidolite roughing underflow. The predetermined reagents include 2500~4000g / t of sodium carbonate, 400~600g / t of water glass, 80~150g / t of modifier and 500~750g / t of collector; The modifier comprises the following components by weight percentage: Aluminum sulfate: 30%~40%; Copper sulfate: 5%~10%; Ethylenediamine phosphate: 30%~40%; Sulfonated polyacrylamide: 10%~20%; The collector comprises the following components: Coconut oil amine: 10%~20%; Tetradecyltrimethylammonium bromide: 20%~30%; Sodium dodecylbenzenesulfonate: 20%~30%; Oxidized paraffin soap: 30%~40%; S5. The lepidolite roughing froth is finely treated to obtain lepidolite concentrate; the lepidolite roughing underflow is scavenged to obtain tailings.

2. The beneficiation method for recovering low-grade lithium mica from tailings ponds according to claim 1, characterized in that: In step S2, the desulfurization flotation includes a primary desulfurization roughing, a primary desulfurization cleaning, and a primary desulfurization scavenging; the middlings obtained from the desulfurization cleaning and the desulfurization scavenging are returned to the desulfurization roughing operation.

3. The beneficiation method for recovering low-grade lithium mica from tailings ponds according to claim 2, characterized in that: The reagents for the desulfurization roughing process include 400-600 g / t of citric acid, 40-60 g / t of copper sulfate, 80-120 g / t of butyl xanthate, and 12-16 g / t of No. 2 oil; the reagents for the desulfurization scavenging process include 40-60 g / t of butyl xanthate and 12-16 g / t of No. 2 oil.

4. The beneficiation method for recovering low-grade lepidolite from tailings ponds according to claim 1, characterized in that: In step S3, the stirring speed is 400~600 r / min; the settling time of the sedimentation and desliming is 4~6 min, the desliming yield is 8%~13%, and the loss rate of Li2O after sedimentation and desliming is 10%~15%.

5. The beneficiation method for recovering low-grade lithium mica from tailings ponds according to claim 1, characterized in that: In step S5, the refining process is performed three times. The reagent used for the first refining is 300-500 g / t of water glass, the reagent used for the second refining is 150-250 g / t of water glass, and the reagent used for the third refining is 80-120 g / t of water glass. The middlings obtained from the first refining are returned to the sedimentation and desliming operation in step S3, the middlings obtained from the second refining are returned to the first refining operation, and the middlings obtained from the third refining are returned to the second refining operation.

6. The beneficiation method for recovering low-grade lepidolite from tailings ponds according to claim 1, characterized in that: In step S5, the scavenging is performed twice. The first scavenging uses 150-250 g / t of the collector, and the second scavenging uses 80-120 g / t of the collector. The middlings obtained from the first scavenging are returned to the sedimentation and desliming operation in step S3, and the middlings obtained from the second scavenging are returned to the first scavenging.

7. The beneficiation method for recovering low-grade lithium mica from tailings ponds according to claim 1, characterized in that: In step S1, the mass concentration of the ore sample in the slurry is 60%~65%; the mass percentage of ore with a particle size of less than 0.074mm in the grinding product is 51%~53%.

8. The beneficiation method for recovering low-grade lithium mica from tailings ponds according to claim 1, characterized in that: In step S2, the predetermined mass concentration is 30% to 35%.

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