Method for sorting high-clay lepidolite

Abstract

This invention relates to the field of mineral processing, providing a method for separating high-mud lepidolite ore, comprising the following steps: crushing the high-mud lepidolite ore; adding water to obtain a slurry with a mass concentration of 20%~40%, adding sodium carbonate, sodium hexametaphosphate, and tragacanth gum to the slurry, stirring and adjusting the slurry; adding a collector and performing roughing; and obtaining lepidolite concentrate through two scavenging and two cleaning processes. By optimizing the crushing process and innovating material selection, efficient recovery of high-mud lepidolite ore and improvement of concentrate quality are achieved. Sodium hexametaphosphate and tragacanth gum form a dual dispersion system. Sodium hexametaphosphate, as a traditional dispersant, charges the surface of the mud particles through electrostatic repulsion, preventing their agglomeration; tragacanth gum, as a natural high-molecular polymer, forms a three-dimensional network structure in the slurry, further stabilizing the dispersion state through steric hindrance. The synergistic effect of the two effectively eliminates the adverse effects of high mud content on flotation, fully exposing the lepidolite particles and improving the adsorption efficiency of the collector.

Description

Technical Field

[0001] This application relates to the field of mineral processing, and in particular to a method for separating high-mud lithium mica. Background Technology

[0002] Lepidolite is an important mineral resource, often associated with gangue minerals such as feldspar and quartz. Due to the different occurrence states of lithium in the minerals and the diverse types of gangue minerals, coupled with the complexity of lithium chemical decomposition processes, the beneficiation process of lithium ore is correspondingly complex. In industrial practice, flotation is widely used both domestically and internationally to process lepidolite ore. Since the minerals present in lepidolite ore are all silicate minerals with similar surface properties, amine reagents are often used as collectors for flotation separation. For example, CN108580051A discloses a beneficiation activator for the lepidolite flotation process, comprising the following raw materials and their weight fractions: fluorite 30-40% by mass and concentrated sulfuric acid 50-60% by mass. In mineral processing, this method effectively removes the obstruction of clay-rich lepidolite concentrate to flotation, increasing recovery by 10-20% and concentrate grade by 1-3%. It is particularly suitable for lepidolite concentrate containing harmful slime, thus improving the flotation efficiency of lepidolite concentrate. CN111298977B discloses a reagent composition for flotation of lepidolite, including a coarse grinding composition and a conditioning composition. The coarse grinding composition includes 40-30 parts by weight of sodium hexametaphosphate, 20-10 parts by weight of sodium tartrate, and 40-60 parts by weight of a collector. The conditioning composition includes 40-60 parts by weight of sodium hexametaphosphate and 60-40 parts by weight of oxalic acid. The preparation methods include methods for preparing the coarse grinding composition and the conditioning composition. The reagent system of this invention is applied to the non-desliming flotation method of lithium mica. The coarse grinding composition is added during the grinding stage to allow the muddy lithium mica and the reagent to fully interact, so as to achieve thorough dispersion of the slurry solution and make the surface of lithium mica hydrophobic. It has the advantages of no need for desliming, high recovery rate and low reagent consumption. CN104741245B provides a capture agent composed of anionic collector sodium oleate or sodium oxidized soap 731 and cationic collector dodecylamine or cocoylamine. In the roughing process of lepidolite, water glass (800-1200 g / t) as a gangue inhibitor, sodium oleate or sodium ochre soap (480-700 g / t) as an anionic collector, and a combination of dodecylamine or cocoylamine (130-160 g / t) as a cationic collector are added. In the fine process, water glass is added as an inhibitor (600-900 g / t in total). In the scavenging process, an anionic collector (130-245 g / t) and a combination of cationic collectors (100-125 g / t) are added to finally obtain lepidolite concentrate and tailings.

[0003] The aforementioned flotation separation sometimes requires a strongly acidic medium to achieve good separation results. However, production in a strongly acidic environment places high demands on the corrosion resistance of various equipment, poses significant safety hazards, has a poor operating environment, and incurs high costs for wastewater treatment. Furthermore, amine collectors produce large amounts of flotation foam with high viscosity and poor fluidity. While flotation using anion-cation combined collectors typically requires the addition of large amounts of water glass or sodium hexametaphosphate to suppress gangue minerals in the ore, these inhibitors have a strong dispersing ability on the pulp, often leading to difficulties in settling the flotation product. In addition, lepidolite deposits suffer from severe weathering, deep erosion, and high levels of mud formation, resulting in a high content of primary mud in lepidolite deposits. Moreover, a certain amount of secondary mud is generated during mining, transportation, crushing, and grinding. Both primary and secondary mud adhere indiscriminately to the surfaces of various minerals in the ore, causing the surfaces of lepidolite and gangue minerals to be homogenized by the mud. These slimes have a significant impact on the flotation efficiency of lepidolite during the beneficiation process, reducing the recovery rate of lithium minerals. At the same time, when the slime content in the lepidolite ore is high, the combined anion and cation collectors will also float the slime to the surface. As the slime accumulates and circulates in the flotation process, the production process will be greatly affected, and the concentrate product will be difficult to meet the standards. Furthermore, since lepidolite ore typically contains a high proportion of mud, desliming treatment is required before flotation. For example, CN114887757B discloses a beneficiation method for lepidolite, in which the raw lepidolite ore is sequentially subjected to grinding, primary desliming, and secondary desliming to obtain sludge and slime. After slurry conditioning, the sludge is subjected to roughing with the addition of a pH adjuster and a collector to obtain a rough concentrate and rough tailings. The rough concentrate is then further refined to obtain a lepidolite concentrate. Finally, a collector is added to the rough tailings for scavenging to obtain a scavenged lepidolite concentrate and tailings. This lepidolite flotation method combines a specific flotation process with a specific collector, making it suitable for processing lepidolite ore with varying mud contents. It has a wide range of applications, and the collector used is easily dissolved, dispersed, and adsorbed on the surface of the lepidolite in the slurry, achieving efficient recovery of lepidolite resources. Currently, desliming before flotation typically uses a 250 cyclone to remove fine particles smaller than 400 mesh. Most lepidolite beneficiation plants still employ pre-desliming processes, leading to lithium resource loss—nearly 20% of lithium minerals are lost, resulting in a significant waste of lithium resources. Furthermore, desliming operations often fail to completely remove the slime, which deteriorates the flotation environment for lithium minerals, consumes large amounts of collectors, and reduces the efficiency of lithium ore beneficiation. With increasing demand for lithium resources, there is an urgent need for a separation method based on high-slime lepidolite to achieve lepidolite separation with high selectivity, good slime resistance, no need for strong acids or alkalis, and strong collecting performance. This is of great significance for improving the comprehensive utilization level of lithium resources in my country. Summary of the Invention

[0004] To address the challenges of complex traditional flotation processes for high-mud-content lepidolite ore, including the deterioration of roughing and cleaning by middlings return, severe mud interference leading to low lithium recovery and low concentrate grade, a new high-mud lepidolite separation method is proposed. This method achieves efficient recovery of high-mud lepidolite ore and improved concentrate quality through optimized crushing processes, innovative material selection, and collaborative design. It employs a conical ball mill with nano-ceramic balls as grinding media, combined with secondary grinding using an abrasive mill. This enables efficient liberation of lepidolite minerals. The extremely small particle size provides more contact points, increasing grinding efficiency and ensuring complete individual liberation of lepidolite from gangue minerals, creating favorable conditions for subsequent flotation. Sodium hexametaphosphate and tragacanth gum form a dual dispersion system. Sodium hexametaphosphate, as a traditional dispersant, charges the surface of the slime particles through electrostatic repulsion, preventing their agglomeration. Tragacanth gum, as a natural polymer, forms a three-dimensional network structure in the pulp, further stabilizing the dispersion state through steric hindrance. The synergistic effect of the two effectively eliminates the adverse effects of high slime content on flotation, fully exposes the lepidolite particles, and improves the adsorption efficiency of the collector.

[0005] Specifically, this invention proposes a method for separating high-mud lithium mica, comprising the following steps:

[0006] S1. Crushing: Crushing the high-mud lepidolite ore to obtain lepidolite raw ore particles;

[0007] S2, Slurry preparation: Add water to the high mud-lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 20%~40%, add sodium carbonate and adjust its pH to 7~8, then add sodium hexametaphosphate and tragacanth gum in sequence, and stir to prepare the slurry;

[0008] S3. Roughing: After slurry preparation, a collector is added, and after stirring, roughing is carried out by flotation machine to obtain lepidolite roughing concentrate and roughing tailings.

[0009] S4. Add yarrow resin and collector to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Then perform a scavenging process to obtain a scavenging concentrate and a scavenging tailings.

[0010] S5. Add yarrow resin and collector to the tailings obtained from the first scavenging in step S4 and mix thoroughly. Then, perform a second scavenging to obtain a second scavenging concentrate and a second scavenging tailings.

[0011] S6. Add sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7-8. Then add sodium hexametaphosphate and mix thoroughly. Perform a first-stage cleaning to obtain a first-stage cleaning concentrate and a first-stage cleaning tailings.

[0012] S7. Perform secondary refining on the primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary refining tailings obtained in step S6 to obtain secondary refined concentrate and secondary refined tailings; wherein the secondary refined concentrate is lithium mica concentrate, and the secondary refined tailings are returned to the downsizing process and step S3 is run.

[0013] Preferably, the high-mud lepidolite is a lepidolite ore with a mud content of 5wt% to 20wt%, wherein the Li2O content in the high-mud lepidolite ore is 0.15wt% to 0.70wt%.

[0014] Preferably, the crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite ore particles to a size of 1-50 μm, wherein the grinding media of the conical ball mill is made of nano-ceramic balls and the grinding concentration is 60%.

[0015] Preferably, in S2, based on the mass of the high-mud lithium mica ore particles, the amount of sodium carbonate added is 400~700g / t, the amount of sodium hexametaphosphate added is 200~400g / t, and the amount of tragacanth gum added is 100~200g / t.

[0016] Preferably, the collector is ammonium dodecyl sulfate. Based on the mass of the high-mud lepidolite ore particles, the amount of collector added in S3 is 1500g / t to 4000g / t; based on the mass of the lepidolite roughing tailings, the amount of tragacanth gum added in S4 is 60 to 80g / t, and the amount of collector added is 100g / t to 300g / t.

[0017] Preferably, based on the mass of the high-mud lithium mica ore particles, the amount of tragacanth gum added in S5 is 10~50g / t, the amount of collector added is 20g / t~80g / t, and the secondary scavenging tailings are flotation tailings.

[0018] Preferably, based on the mass of the high-mud lithium mica ore particles, in S6, based on the mass of the roughing concentrate, the amount of sodium carbonate added is 100~300g / t, and the amount of sodium hexametaphosphate added is 50~100g / t.

[0019] Preferably, the roughing process specifically involves adding 1500g / t to 4000g / t of lepidolite collector based on the mass of the high-mud lepidolite ore particles, stirring for 5 to 10 minutes, and flotation for 2 to 5 minutes to obtain roughing concentrate and roughing tailings.

[0020] Preferably, the scavenging process specifically involves adding tragacanth gum and a collector, stirring for 2-5 minutes, and then flotating for 3-7 minutes to obtain scavenged concentrate and scavenged tailings.

[0021] Preferably, the first fine selection specifically involves adding 100-300 g / t of sodium carbonate and 50-100 g / t of sodium hexametaphosphate, stirring for 2-5 minutes, and then fine selection for 1-3 minutes.

[0022] The beneficial effects of this invention include:

[0023] 1. Synergistic Effect of Complete Mineral Liberation and Dispersion: This invention employs a conical ball mill combined with nano-ceramic balls for grinding, along with the dual dispersing effects of sodium hexametaphosphate and tragacanth gum. This ensures complete liberation and uniform dispersion of lepidolite from gangue minerals, significantly improving the floatability of lepidolite. Combined with ammonium dodecyl sulfate collector, it achieves flotation separation of lepidolite from other minerals and significantly inhibits the deterioration of roughing and cleaning product indicators by slime. Testing shows that the degree of liberation of lepidolite monomers in the slurry treated using this method is significantly higher than that of traditional methods.

[0024] 2. Synergistic Effect of Flotation Materials: By precisely controlling the amount and composition of added materials at different flotation stages, selective and efficient collection of lepidolite is achieved. In the roughing stage, the addition of tragacanth gum enhances the dispersibility of the slurry, allowing the collector to be more effectively adsorbed onto the surface of the lepidolite. In the scavenging stage, the synergistic effect of tragacanth gum and the collector further improves the recovery rate of lepidolite. Experiments show that compared with traditional reagent systems, the method of this invention can significantly improve the recovery rate of lepidolite, obtaining high-grade lepidolite ore.

[0025] 3. By employing a roughing-scavenging-cleaning separation process and recycling the tailings from the secondary cleaning process, efficient enrichment of lepidolite and maximum utilization of resources are achieved. The secondary cleaning process effectively improves the concentrate grade, while recycling the tailings from the secondary cleaning process reduces the loss of lepidolite. In practical applications, the method of this invention can obtain lepidolite concentrate with a Li2O grade ≥8.5% and a recovery rate ≥90%, which is significantly improved compared to traditional processes. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein. The reagents used herein may be commercially available related products, and performance testing standards refer to industry or national standards.

[0028] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0029] The features and performance of this application will be further described in detail below with reference to embodiments:

[0030] Example 1

[0031] A method for separating high-mud lithium mica, wherein the high-mud content is 15wt%~20wt% and the Li2O content is 0.70wt%, comprising the following steps:

[0032] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles; the crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 50μm. The grinding media in the conical ball mill are nano-ceramic balls, and the grinding concentration is 60%.

[0033] S2, Slurry preparation: Add water to the high mud-lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 20%, add 700g / t sodium carbonate to it and adjust its pH to 7, then add 200g / t sodium hexametaphosphate and 200g / t tragacanth gum in sequence, and stir to prepare the slurry.

[0034] S3. Roughing: After slurry preparation, add 4000g / t ammonium dodecyl sulfate, stir for 10 minutes, and then float in a flotation machine for 5 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0035] S4. Add 80g / t tragacanth gum and 100g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Stir for 5 minutes and float for 7 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0036] S5. Add 50g / t tragacanth gum and 80g / t ammonium dodecyl sulfate to the primary scavenging tailings obtained in step S4 and mix thoroughly. Stir for 5 minutes and float for 7 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0037] S6. Add 300g / t sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7. Then add 50g / t sodium hexametaphosphate and mix thoroughly. Stir for 5 minutes and then perform a first-stage cleaning process for 3 minutes to obtain a first-stage cleaning concentrate and a first-stage cleaning tailings.

[0038] S7. The primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 are stirred for 5 minutes and then cleaned for 3 minutes to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 8.92%, the yield is 7.15%, the Li2O recovery rate is 91.2%, and the lithium oxide content in the tailings is 0.03%.

[0039] Example 2

[0040] A method for separating high-mud lithium mica, wherein the high-mud content is 5wt%~10wt% and the Li2O content is 0.15wt%, comprising the following steps:

[0041] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles. The crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 10~50μm. The grinding media in the conical ball mill are nano-ceramic balls, and the grinding concentration is 60%.

[0042] S2, Slurry preparation: Add water to the high mud-lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 40%. Add 400g / t sodium carbonate to it and adjust its pH to 8. Then add 400g / t sodium hexametaphosphate and 100g / t tragacanth gum in sequence and stir to prepare the slurry.

[0043] S3. Roughing: After slurry preparation, add 1500g / t ammonium dodecyl sulfate, stir for 5 minutes, and then float in a flotation machine for 2 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0044] S4. Add 60g / t tragacanth gum and 300g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Stir for 2 minutes and float for 3 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0045] S5. Add 10g / t tragacanth gum and 20g / t ammonium dodecyl sulfate to the tailings obtained in step S4 and stir thoroughly. Then, stir for 2 minutes and float for 3 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0046] S6. Add 100g / t sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 8. Then add 100g / t sodium hexametaphosphate and mix thoroughly. Stir for 2 minutes and then perform a 1-minute fine-selection process to obtain a fine-selected concentrate and a fine-selected tailings.

[0047] S7. The primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 are stirred for 2 minutes and then subjected to secondary cleaning for 1 minute to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 8.51%, the yield is 1.62%, the Li2O recovery rate is 92.4%, and the lithium oxide content in the tailings is 0.045%.

[0048] Example 3

[0049] A method for separating high-mud lithium mica, wherein the high-mud content is 5wt%~20wt% and the Li2O content is 0.50wt%, comprising the following steps:

[0050] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles; the crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 1~30μm, wherein the grinding media of the conical ball mill uses nano-ceramic balls, and the grinding concentration is 60%;

[0051] S2, Slurry preparation: Add water to the high mud lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 30%. Add 500g / t sodium carbonate to it and adjust its pH to 7.5. Then add 300g / t sodium hexametaphosphate and 200g / t tragacanth gum in sequence and stir to prepare the slurry.

[0052] S3. Roughing: After slurry preparation, add 2500g / t ammonium dodecyl sulfate, stir for 8 minutes, and then float in a flotation machine for 3 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0053] S4. Add 70g / t tragacanth gum and 200g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Stir for 3 minutes and float for 5 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0054] S5. Add 40g / t tragacanth gum and 50g / t ammonium dodecyl sulfate to the primary scavenging tailings obtained in step S4 and mix thoroughly. Then, stir for 4 minutes and float for 6 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0055] S6. Add 150g / t sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7.5. Then add 80g / t sodium hexametaphosphate and mix thoroughly. Stir for 4 minutes and then finely clean for 2 minutes to obtain a first-fine concentrate and a first-fine tailings.

[0056] S7. The primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 are stirred for 3 minutes and then cleaned for 2 minutes to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 8.72%, the yield is 5.18%, the Li2O recovery rate is 90.35%, and the lithium oxide content in the tailings is 0.063%.

[0057] Comparative Example 1

[0058] A method for separating high-mud lithium mica, wherein the high-mud content is 5wt%~20wt% and the Li2O content is 0.50wt%, comprising the following steps:

[0059] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles; the crushing is carried out using a conical ball mill, grinding the lepidolite raw ore particles to a size of 75μm, wherein the grinding media of the conical ball mill is made of nano-ceramic balls, and the grinding concentration is 60%;

[0060] S2, Slurry preparation: Add water to the high mud lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 30%, add 500g / t sodium carbonate to it and adjust its pH to 7.5, then add 300g / t sodium hexametaphosphate and stir to prepare the slurry.

[0061] S3. Roughing: After slurry preparation, add 2500g / t ammonium dodecyl sulfate, stir for 8 minutes, and then float in a flotation machine for 3 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0062] S4. Add 200g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Stir for 3 minutes and float for 5 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0063] S5. Add 50g / t of ammonium dodecyl sulfate to the tailings obtained in step S4 and mix thoroughly. Then, stir for 4 minutes and float for 6 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0064] S6. Add 150g / t sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7.5. Then add 80g / t sodium hexametaphosphate and mix thoroughly. Stir for 4 minutes and then finely clean for 2 minutes to obtain a first-fine concentrate and a first-fine tailings.

[0065] S7. The primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 are stirred for 3 minutes and then cleaned for 2 minutes to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 3.82%, the yield is 35.3%, the Li2O recovery rate is 9.56%, and the lithium oxide content in the tailings is 0.24%.

[0066] Comparative Example 2

[0067] A method for separating high-mud lithium mica, wherein the high-mud content is 5wt%~20wt% and the Li2O content is 0.50wt%, comprising the following steps:

[0068] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles; the crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 1~30μm, wherein the grinding media of the conical ball mill uses nano-ceramic balls, and the grinding concentration is 60%;

[0069] S2, Slurry preparation: Add water to the high mud lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 30%, add 500g / t sodium carbonate to it and adjust its pH to 7.5, then add 300g / t sodium hexametaphosphate and stir to prepare the slurry.

[0070] S3. Roughing: After slurry preparation, add 2500g / t ammonium dodecyl sulfate, stir for 8 minutes, and then float in a flotation machine for 3 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0071] S4. Add 200g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Stir for 3 minutes and float for 5 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0072] S5. Add 50g / t of ammonium dodecyl sulfate to the tailings obtained in step S4 and mix thoroughly. Then, stir for 4 minutes and float for 6 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0073] S6. Add 150g / t sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7.5. Then add 80g / t sodium hexametaphosphate and mix thoroughly. Stir for 4 minutes and then finely clean for 2 minutes to obtain a first-fine concentrate and a first-fine tailings.

[0074] S7. The primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 are stirred for 3 minutes and then cleaned for 2 minutes to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 1.67%, the yield is 14.6%, the Li2O recovery rate is 48.76%, and the lithium oxide content in the tailings is 0.23%.

[0075] Comparative Example 3

[0076] A method for separating high-mud lithium mica, wherein the high-mud content is 5wt%~20wt% and the Li2O content is 0.50wt%, comprising the following steps:

[0077] S1. Crushing: The high-mud lepidolite ore is crushed to obtain lepidolite raw ore particles; the crushing process involves sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 1~30μm, wherein the grinding media of the conical ball mill uses nano-ceramic balls, and the grinding concentration is 60%;

[0078] S2. Desliming treatment: The crushed lepidolite ore is deslimed by cyclone desliming.

[0079] S3. Slurry preparation: Add water to the deslimed high-mud lithium mica ore particles obtained in S2 to obtain a slurry with a mass concentration of 30%. Add 500g / t sodium carbonate to it and adjust its pH to 7.5. Then add 300g / t sodium hexametaphosphate and 200g / t tragacanth gum in sequence and stir to prepare the slurry.

[0080] S4. Roughing: After slurry preparation, add 2500g / t ammonium dodecyl sulfate, stir for 8 minutes, and then float in a flotation machine for 3 minutes to obtain lepidolite roughing concentrate and roughing tailings.

[0081] S5. Add 70g / t tragacanth gum and 200g / t ammonium dodecyl sulfate to the lepidolite roughing tailings obtained in step S4 and mix thoroughly. Stir for 3 minutes and float for 5 minutes to obtain a first scavenging concentrate and a first scavenging tailings.

[0082] S6. Add 40g / t tragacanth gum and 50g / t ammonium dodecyl sulfate to the primary scavenging tailings obtained in step S5 and stir thoroughly. Then, stir for 4 minutes and float for 6 minutes to obtain secondary scavenging concentrate and secondary scavenging tailings. The secondary scavenging tailings are the flotation tailings.

[0083] S7. Add 150g / t sodium carbonate to the rough concentrate obtained in step S4 and adjust its pH to 7.5. Then add 80g / t sodium hexametaphosphate and mix thoroughly. Stir for 4 minutes and then finely clean for 2 minutes to obtain a first-fine concentrate and a first-fine tailings.

[0084] S8. The primary scavenging concentrate obtained in step S5, the secondary scavenging concentrate obtained in step S6, and the primary cleaning tailings obtained in step S7 are stirred for 3 minutes and then cleaned for 2 minutes to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lepidolite concentrate. Testing shows that the lithium oxide content in the obtained lepidolite concentrate product is 7.62%, the yield is 3.37%, the Li2O recovery rate is 51.4%, and the lithium oxide content in the tailings is 0.33%.

[0085] The separation methods in Examples 1-3 of this invention do not undergo pre-desliming treatment and do not involve desliming during the separation process. The resulting lepidolite concentrate has a high grade, with lithium oxide content exceeding 8.5% and a total recovery rate exceeding 90%. Furthermore, the grade of the obtained lepidolite concentrate is significantly higher than that in Comparative Examples 1-2. The lithium oxide grade in the tailings is lower than in the comparative examples. Comparative Example 1 uses conventional depressants for the flotation of lepidolite ore. Due to their low dispersibility, the grade and recovery rate of the final lepidolite concentrate are significantly lower than in the examples. The high-mud lepidolite separation method of this invention can directly use lepidolite ore without pre-desliming treatment. The lithium grade in the lepidolite concentrate obtained by direct flotation is significantly improved compared to conventional flotation methods, while also significantly reducing the lithium grade in the flotation tailings, thus increasing the lithium recovery rate. The comparative examples show that desliming treatment has an adverse effect on lithium recovery.

[0086] The preferred embodiments of the present invention have been described in detail above, and 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for sorting high-mud lithium mica, characterized in that, Includes the following steps: S1. Crushing: Crushing the high-mud lepidolite ore to obtain lepidolite raw ore particles. The high-mud lepidolite is lepidolite ore with a mud content of 5wt%~20wt%. The crushing is carried out by sequentially using a conical ball mill and an abrasive mill to grind the lepidolite raw ore particles to a size of 1~50μm. S2, Slurry preparation: Add water to the high-mud lithium mica ore particles obtained in S1 to obtain a slurry with a mass concentration of 20%~40%. Add sodium carbonate and adjust its pH to 7~8. Then add sodium hexametaphosphate and tragacanth gum in sequence and stir to prepare the slurry. Based on the mass of the high-mud lithium mica ore particles, the amount of sodium carbonate added in this step is 400~700g / t, the amount of sodium hexametaphosphate added is 200~400g / t, and the amount of tragacanth gum added is 100~200g / t. S3. Roughing: After slurry preparation, ammonium dodecyl sulfate collector is added, and after stirring, roughing is carried out by flotation machine to obtain lepidolite rough concentrate and rough tailings. Based on the mass of high mud lepidolite ore particles, the amount of ammonium dodecyl sulfate collector added in this step is 1500g / t~4000g / t. S4. Add tragacanth gum and ammonium dodecyl sulfate collector to the lepidolite roughing tailings obtained in step S3 and mix thoroughly. Then, perform a scavenging process to obtain a scavenging concentrate and a scavenging tailings. Based on the mass of the lepidolite roughing tailings, the amount of tragacanth gum added in this step is 60~80g / t, and the amount of ammonium dodecyl sulfate collector added is 100g / t~300g / t. S5. Add yarrow gum and ammonium dodecyl sulfate collector to the primary scavenging tailings obtained in step S4 and mix thoroughly. Then, perform secondary scavenging to obtain secondary scavenging concentrate and secondary scavenging tailings. S6. Add sodium carbonate to the rough concentrate obtained in step S3 and adjust its pH to 7-8. Then add sodium hexametaphosphate and mix thoroughly. Perform a first-stage cleaning to obtain a first-stage cleaning concentrate and a first-stage cleaning tailings. Based on the mass of the rough concentrate, the amount of sodium carbonate added in this step is 100-300 g / t, and the amount of sodium hexametaphosphate added is 50-100 g / t. S7. Perform secondary cleaning on the primary scavenging concentrate obtained in step S4, the secondary scavenging concentrate obtained in step S5, and the primary cleaning tailings obtained in step S6 to obtain secondary cleaning concentrate and secondary cleaning tailings; wherein the secondary cleaning concentrate is lithium mica concentrate, and the secondary cleaning tailings are returned to the pulping and step S3 is run.

2. The sorting method for high-mud lithium mica according to claim 1, characterized in that, The Li2O content in the high-mud lithium mica ore is 0.15wt%~0.70wt%.

3. The sorting method for high-mud lithium mica according to claim 1, characterized in that, The conical ball mill uses nano-ceramic balls as its grinding media, with a grinding concentration of 60%.

4. The sorting method for high-mud lithium mica according to claim 1, characterized in that, Based on the mass of high-mud lithium mica ore particles, the amount of tragacanth gum added in S5 is 10~50g / t, the amount of collector added is 20g / t~80g / t, and the secondary scavenging tailings are flotation tailings.

5. The sorting method for high-mud lithium mica according to claim 1, characterized in that, The roughing process specifically involves stirring for 5-10 minutes and flotation for 2-5 minutes to obtain roughing concentrate and roughing tailings.

6. The sorting method for high-mud lithium mica according to claim 1, characterized in that, The scavenging process specifically involves adding yarrow gum and a collector, stirring for 2-5 minutes, and then flotating for 3-7 minutes to obtain scavenged concentrate and scavenged tailings.

7. The sorting method for high-mud lithium mica according to claim 1, characterized in that, The first fine selection process specifically involves adding 100-300 g / t of sodium carbonate and 50-100 g / t of sodium hexametaphosphate, stirring for 2-5 minutes, and then fine selection for 1-3 minutes.