A mineral processing method for comprehensive recovery of lithium-beryllium resources in fluorite tailings

Abstract

The present invention discloses a mineral processing method for the comprehensive recovery of lithium-beryllium resources from fluorite tailings, belonging to the field of mineral processing technology. Based on the surface property differences of fluorite-associated lithium-beryllium minerals, this method first uses a metal-organic complex and fatty acids as a composite collector for the co-enrichment of fluorite and beryllium minerals, preferentially flotating fluorite and beryllium minerals. Fluorite and beryllium concentrate are then separated by flotation using the principle of suppressing beryllium minerals. The mixed flotation tailings are activated with high-valent metal ions and then subjected to lithium flotation to obtain a lithium concentrate. This method can produce qualified metallurgical-grade fluorite and a lepidolite concentrate with a Li₂O grade of 1.2%, achieving a CaF₂ recovery rate of over 55% and a Li₂O recovery rate of over 65%. It can also produce a beryllium concentrate with a BeO grade of 2.0% and a recovery rate of 40%. This method effectively achieves the deep, comprehensive recovery of fluorite and associated lithium-beryllium resources from fluorite tailings, with excellent social value and economic benefits.

Description

Technical Field

[0001] The present invention relates to a method for processing fluorite tailings, in particular to a method for comprehensively recovering multiple beryllium minerals such as chrysoberyl, ferroxanite, beryl and the like, as well as partial mixed preferential flotation of fluorite and lepidolite from fluorite tailings, belonging to the technical field of mineral processing. Background Art

[0002] Against the backdrop of the global transition to renewable energy, lithium resources, as a key raw material in new energy vehicles, energy storage systems, and other fields, play a vital role in achieving sustainable development goals. Beryllium, often called a "super metal" and a "cutting-edge metal," is widely used in high-precision and cutting-edge fields such as the nuclear industry and aerospace due to its unique physical and chemical properties. It is an irreplaceable key material for the future development of high-tech fields.

[0003] Prior art development of lithium resources has primarily focused on the relatively easy-to-separate spodumene and the development of lithium extraction technologies from salt lakes. However, beryllium beneficiation technology is virtually nonexistent, with only a few reports on beryl flotation, which remains largely at the laboratory level. With the increasing depletion of high-quality single-metal deposits, the efficient development of co-existing lithium-beryllium resources in polymetallic ores has become a technical challenge. For example, a polymetallic mine in Hunan Province, my country, contains a shallow deposit of beryllium-bearing fluorite and a deeper deposit of tin-polymetallic co-existing fluorite. The raw ore contains 0.11% BeO as the associated beryllium mineral, along with lepidolite containing 0.36% Li₂O. During the roughing of the fluorite, these lithium-beryllium minerals are suppressed by water glass and fall into the tailings, preventing effective recovery. Furthermore, these tailings are directly discharged into tailings ponds, resulting in high tailings disposal costs, significant environmental pressures, and significant waste of lithium-beryllium resources. Therefore, it is of great significance to achieve comprehensive recovery of lithium-beryllium resources in this part of fluorite tailings.

[0004] Lepidolite and beryllium-containing minerals (including beryl Be3Al2[Si6O 18], hydroxysilicate beryllite Be4[(OH)2|Si2O7], chrysoberyl BeAl2O4, heliotrope Mn8[BeSiO4]6S2, taaffeite MgBeAl4O8, and beryllite H2Be4Si2O9 are generally aluminosilicate minerals. Without activation, they all exhibit poor floatability, making selective separation difficult. However, it is worth noting that their spatial structures, constructed with [SiO4] and [AlO6] as their frameworks, differ somewhat in their bond breakage characteristics and surface properties during the dissociation process. Fluorite has good floatability and is easily recovered by flotation with fatty acid collectors containing carboxyl groups (-COOH). In the prior art, Chinese patent CN115228599A proposes a method for pre-enrichment of chrysoberyl-type beryllium ore. This method uses a technical solution of floating and sinking to remove carbonate gangue, desulfurization, and floating fluorite to suppress beryllium. However, the overall process is complex, the grade of the reverse flotation beryllium concentrate is low, and the associated lithium resources are not recovered, resulting in low resource utilization. There are few other reports on this aspect.

[0005] In summary, the development of a mineral processing method for the comprehensive recovery of lithium-beryllium resources in fluorite tailings will have important guiding significance for the in-depth development and utilization of co-existing lithium-beryllium resources. Summary of the Invention

[0006] In view of the defect in the prior art that valuable lithium-beryllium resources in fluorite tailings cannot be effectively recovered and are seriously wasted, the purpose of the present invention is to provide a mineral processing method for the comprehensive recovery of lithium-beryllium resources in fluorite tailings. The method adopts a process flow of partial mixed preferential flotation to preferentially co-enrich fluorite and beryllium minerals to obtain a mixed concentrate, and further separates the two based on the difference in surface properties. The mixed flotation tailings adopt metal ion activation flotation to obtain lepidolite concentrate, truly realizing the comprehensive resource recovery of fluorite co-associated lithium-beryllium minerals.

[0007] In order to achieve the above technical objectives, the present invention provides a beneficiation method for comprehensive recovery of lithium-beryllium resources in fluorite tailings, which comprises the following steps:

[0008] 1) adjusting the pH of the fluorite tailings slurry to alkaline, and performing flotation I using a metal organic complex and a fatty acid as a composite collector to obtain a mixed concentrate of fluorite and beryllium and tailings I;

[0009] 2) After the mixed concentrate is slurried, flotation II is performed using causticized starch or acidified water glass as an inhibitor and fatty acids as a collector to obtain metallurgical-grade fluorite concentrate and tailings II, where the tailings II are beryllium concentrate products;

[0010] 3) After the tailings I are activated by high-valent metal ions, flotation III is performed using fatty acids as collectors and inorganic phosphates as inhibitors to obtain lithium concentrate.

[0011] The mineral processing method for comprehensive recovery of lithium-beryllium resources in fluorite tailings provided by the present invention is based on the surface characteristics and floatability differences of fluorite, beryllium minerals and mica, and realizes the synchronous flotation co-enrichment and selective separation of fluorite and beryllium minerals through targeted adsorption and highly selective inhibitors of metal-organic complexes and fatty acid composite collectors, and further obtains lithium concentrate products through high-valent metal ion activation flotation, ultimately realizing the comprehensive recovery of lithium-beryllium resources in fluorite tailings. More specifically, the technical solution of the present invention, based on the characteristics of the mineral composition and occurrence state of fluorite tailings (the main valuable minerals are fluorite, lepidolite, chrysoberyl, hydroxysilicon beryllite and other beryllium minerals, and the gangue minerals are mainly muscovite, sodium pearl mica, quartz, and feldspar), uses metal organic complexes and fatty acid composite collectors to preferentially float fluorite and beryllium minerals in the form of mixed concentrates, achieving simultaneous enrichment and recovery. A starch inhibitor with good chelating and coordination ability with aluminum particles on the surface of beryllium minerals is further used to achieve targeted inhibition of beryllium minerals, thereby obtaining a beryllium concentrate product. Acidified water glass is then used as an inhibitor to obtain metallurgical-grade fluorite, thereby achieving efficient separation of beryllium and fluorite. The mixed flotation tailings are activated with high-valent metal ions, fatty acids are used as collectors, and inorganic phosphates are used as inhibitors to suppress silicate gangue minerals such as kaolinite and chlorite, and the lepidolite concentrate product is obtained by flotation.

[0012] As a preferred embodiment, the fluorite tailings contain lithium minerals including lepidolite and beryllium minerals including at least one of chrysoberyl, ferroxenite, beryl, taaffeite, and beryl. More specifically, the fluorite tailings contain silicate minerals such as muscovite at a mass content of ≥50%, BeO at a mass content of ≥0.26%, Li2O at a mass content of ≥0.6%, and CaF2 at a mass content of 5-15%.

[0013] As a preferred solution, the concentration of the fluorite tailings slurry is controlled at 40-50wt.%, and the pH is adjusted to 10.0-12.0; wherein, the pH is adjusted using a composite alkali composed of caustic soda and soda ash in a mass ratio of (1-4):1. The pH is further preferably adjusted to 10.5-11.5. The mixed alkali is further preferably formed by compounding caustic soda and soda ash in a mass ratio of (1-2):1. The flotation of beryllium minerals is more sensitive to the pH conditions of the slurry. Therefore, the use of soda ash as a buffer can maintain the stability of the slurry pH and effectively disperse the negatively charged ore mud on the surface by compressing the double layer. At the same time, the alkaline slurry environment adjusted by caustic soda is conducive to eliminating the influence of some inevitable metal ions, and can also promote the participation of some hydroxides in coordination, which is beneficial to the targeted adsorption of the collector.

[0014] As a preferred embodiment, the metal-organic complex is formed by the coordination assembly of a divalent or trivalent metal ion and a hydroxamic acid organic ligand in a molar ratio of 1:(1 to 12). The metal-organic complex is further preferably formed by the coordination assembly of a divalent or trivalent metal ion and a hydroxamic acid organic ligand in a molar ratio of 1:(1 to 6). The metal-organic complex uses metal ions as polar groups and has a targeted adsorption effect on the Al-O active sites on the mineral surface, which can achieve the simultaneous capture of various beryllium minerals such as chrysoberyl and beryllite.

[0015] As a more preferred solution, the divalent or trivalent metal ion is Ca 2+ Mg 2+ 、Zn 2+ 、Fe 2+ , Pb 2+ 、Cu 2 + 、Mn 2+ 、Fe 3+ or Al 3+ The divalent or trivalent metal ion is further preferably Pb 2+ 、Fe 2+ or Fe 3+ .

[0016] As a more preferred solution, the hydroxamic acid organic ligand is benzohydroxamic acid, salicylic hydroxamic acid, benzenesulfonyl hydroxamic acid, 1-naphthohydroxamic acid and C6~C 12 At least one of the alkyl hydroxamic acids. 12 The alkyl hydroxamic acid may be a linear alkyl group or a branched alkyl hydroxamic acid group.

[0017] As a more preferred solution, the fatty acids include at least one of sodium oleate, linoleic acid, cyclohexane acid, tall oil, lauric acid, linolenic acid, palmitic acid, stearic acid, ricinoleic acid, and 731 oxidized paraffin soap.

[0018] As a preferred solution, the flotation I includes one roughing selection, two cleaning selections and one scavenging selection.

[0019] As a more preferred solution, the roughing agent system is as follows: the composite collector dosage is 400-800 g / t; the metal organic complex and fatty acid in the composite collector are measured according to a mass ratio of hydroxamic acid organic ligand to fatty acid of (1-4):1. The metal organic complex and fatty acid are further preferably measured according to a mass ratio of hydroxamic acid organic ligand to fatty acid of (1-2):1. The combination of fatty acids and metal-based complexes has both capture ability and selectivity. Through the efficient synergistic effect of the two, the critical micelle concentration of the collector adsorbed at the solid / liquid interface can be reduced, thereby enhancing the effective recovery of the target beryllium minerals and fluorite.

[0020] As a preferred solution, the reagent system for sweeping is: the amount of composite collector used is halved relative to that of roughing.

[0021] As a preferred solution, blank selection is used. The purpose of blank selection is to remove gangue minerals that have not absorbed the reagents during the roughing process and have floated up due to foam entrainment, thereby improving the quality of the mixed concentrate.

[0022] The present invention can achieve effective co-enrichment of fluorite and beryllium minerals by optimizing the mixed flotation reagent system. The CaF2 mass content in the mixed concentrate obtained by open-circuit flotation is ≥40%, and the BeO mass content is ≥1.0%.

[0023] As a preferred solution, the mixed concentrate is slurried to a pH of 9.0 to 10.0. The slurry adjustment process of the mixed concentrate is to adjust the slurry pH to 9.0 to 10.0 with sodium carbonate. Under this slurry pH condition, fluorite is more conducive to floating.

[0024] As a preferred embodiment, the causticized starch is obtained by modifying starch with caustic soda. As a more preferred embodiment, the starch includes at least one of soluble starch, corn starch, potato starch, and rice starch. The causticized starch is formed by modifying starch with caustic soda at a mass ratio of 1:(1-10) under heating conditions of 40-60°C. More preferably, the soluble starch has a mass ratio of caustic soda to soluble starch of 1:(4-6). The causticizing treatment of starch with caustic soda can enhance the solubility of starch and strengthen its ability to chelate and cyclize with metal ions.

[0025] As a preferred solution, the flotation II includes one roughing selection, one scavenging selection and 2 to 3 cleaning selections.

[0026] As a preferred solution, the roughing agent system (compared to the addition of agents to the mixed concentrate) is as follows: the fatty acid dosage is 50-100 g / t, and the causticized starch dosage is 50-250 g / t. The roughing tailings are the beryllium concentrate, and the foam product is further refined to obtain the fluorite concentrate. The causticized starch dosage is more preferably 50-250 g / t.

[0027] As a more preferred solution, the above-mentioned reagent system for the beneficiation is: the amount of acidified water glass is 500-1000 g / t, and is gradually halved with the number of beneficiation steps. The amount of acidified water glass is more preferably 600-1200 g / t.

[0028] As a more preferred solution, the agent system for the sweeping selection is: the amount of fatty acids used is halved relative to the roughing selection.

[0029] As a more preferred solution, the scavenged ores are returned to the previous operation in sequence.

[0030] The present invention utilizes a reagent system for concentrating and scavenging during flotation II, respectively, with the dosage of acidified water glass and fatty acids decreasing in stages, with middlings returned sequentially. This optimized reagent system can produce a metallurgical-grade fluorite concentrate with a CaF2 mass content of ≥75% and a recovery rate of ≥55%, and a beryllium concentrate with a BeO mass content of ≥2.0% and a recovery rate of ≥40%.

[0031] As a preferred solution, the high-valent metal ions include Mg 2+ 、Zn 2+ , Pb 2+ 、Al 3+ or Fe 3+ The high-valent metal ion is further preferably Mg 2+ 、Zn 2+ or Pb 2+ .

[0032] As a preferred embodiment, the inorganic phosphate includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate. The inorganic phosphate is further preferably sodium hexametaphosphate. The anions generated by hydrolysis and ionization of this type of inhibitor in aqueous solution can significantly reduce the adsorption of the collector on silicate gangue minerals such as quartz, feldspar, kaolinite, and chlorite by selectively complexing certain metal ions. Furthermore, it can act as a dispersant, increasing the steric hindrance and electrostatic repulsion between particles, helping to reduce the agglomeration of mineral particles and improving the flotation efficiency of lepidolite.

[0033] As a preferred solution, the flotation III includes one roughing selection, one cleaning selection and 2 to 3 scavenging selections.

[0034] As a preferred embodiment, the roughing agent system is as follows: the dosage of high-valent metal ions is 200-800 g / t, the dosage of inorganic phosphate is 50-250 g / t, the dosage of fatty acids is 1000-2000 g / t, and the dosage of foaming agent is 10-40 g / t. The roughing agent system is further preferably as follows: the dosage of high-valent metal ions is 400-600 g / t, the dosage of inorganic phosphate is 100-200 g / t, the dosage of fatty acids is 1000-1500 g / t, and the dosage of No. 2 oil is 20-30 g / t.

[0035] As a preferred solution, the pH of the pulp system is stabilized between 9.0 and 10.0 during the roughing process. Under these weakly alkaline conditions, metal ions are adsorbed on the lepidolite surface in the form of hydroxyl complexes / metal hydroxide precipitates, which is more conducive to the chemical adsorption of fatty acids.

[0036] As a more preferred solution, the selection is blank selection.

[0037] As a more preferred solution, the drug selection system is as follows: the amount of fatty acids used decreases step by step.

[0038] The lepidolite of the present invention is a typical TOT structure layered silicate mineral. It is easy to break along the interlayer during dissociation. The relative density of surface anions is high and it can be effectively activated by multivalent metal cations. Fatty acids are further used as collectors. The carboxyl group can coordinate the active metal particles to form a collector double film or fatty acid-metal ion precipitation, thereby making the lepidolite hydrophobic and float. As a more preferred solution, a very small amount of 2# oil is introduced as a foaming agent in the metal ion activation flotation system to significantly improve the foam stability. Through the preferred solution, the lepidolite concentrate is obtained. The mass content of Li2O is ≥1.2% and the recovery rate is ≥65%.

[0039] The acidified water glass described in this invention is a conventional depressant for fluorite concentrating in the prior art. It is formed by mixing sulfuric acid and water glass in a mass ratio of 1:(1-4), preferably 1:(1-2). Compared to single water glass, acidified water glass has a stronger silica reduction effect, improves flotation foam, enhances secondary enrichment, and increases fluorite flotation efficiency.

[0040] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0041] 1. The technical solution of the present invention applies the idea of ​​"partial mixed preferential flotation" to the recovery of lithium-beryllium resources in fluorite tailings. Compared with the conventional process of first removing fluorite and then selecting lepidolite, the technical solution of the present invention ensures the effective recovery of fluorite and lithium resources while taking into account the recovery of part of beryllium. Not only can metallurgical-grade fluorite and lepidolite concentrate products be obtained, but also beryllium concentrate products with BeO ≥ 2.0% can be produced.

[0042] 2. The present invention has developed a metal-based complex + fatty acid flotation agent system with a synchronous capture effect on various beryllium minerals, which preferentially recovers beryllium minerals and fluorite by synchronous flotation to obtain a mixed concentrate in which fluorite and beryllium are co-enriched. Then, causticized starch with a targeted chelating effect on the surface of beryllium minerals is used as an inhibitor to efficiently separate the beryllium minerals as a concentrate product.

[0043] 3. Compared with the conventional cation / anion cation system for mica selection, the technical solution of the present invention adopts metal ion activation flotation technology to achieve effective recovery of lepidolite. The entire flotation process is maintained under alkaline / weakly alkaline conditions, with low reagent consumption and low cost.

[0044] 4. Compared with lithium-beryllium minerals with similar surface characteristics and difficult separation, the technical solution of the present invention greatly reduces the beryllium element entering the lithium concentrate by preferentially mixing beryllium minerals and fluorite, floating them out, and then efficiently separating them, thereby avoiding the risk of beryllium pollution in the generation of beryllium-containing wastewater and solid waste during the lithium smelting process.

[0045] In summary, the technical solution of the present invention has the characteristics of short process, simple operation, and strong adaptability. It truly realizes the effective comprehensive recovery of lithium and beryllium resources in fluorite tailings. It is of great significance to ensure the sustainable development of my country's beryllium smelting industry and ensure the safety of key lithium and beryllium mineral resources, and is conducive to large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of the principle of the present invention.

[0047] Figure 2 This is a flow chart of the conventional fluorite removal-lithium selection process of Comparative Example 1.

[0048] Figure 3 This is the process flow chart of Example 1. DETAILED DESCRIPTION

[0049] The following examples are provided to further illustrate the present invention in detail, but are not intended to limit the scope of protection of the claims of the present invention.

[0050] Comparative Example 1 (Compared with Example 1)

[0051] Under stirring conditions, sulfuric acid of the same concentration and a water glass solution are uniformly mixed in a mass ratio of 1:2 to obtain the acidified water glass inhibitor.

[0052] For a fluorite tailing in Hunan, the ore fineness is 80%, the BeO content in the ore sample is 0.26%, and the Li2O content is 0.74%, which has a high recovery value. The main mineral composition is shown in Table 1 below. As can be seen from the table, the main body of the fluorite tailing is mica minerals, including 33.96% muscovite (sericite), 12.11% sodium pearl mica, etc. At the same time, the CaF2 content accounts for 13.65%. It also contains a small amount of silicate gangue minerals such as chlorite, kaolinite, quartz, and feldspar. The main beryllium minerals are chrysoberyl and hydroxysilicate beryllite, and a small part exists in the form of bluestone and beryl. The occurrence state is complex and the sorting is difficult.

[0053] Use Figure 2In the fluorite removal and lithium selection process shown in the figure, the fluorite tailings are adjusted to a slurry pH of 10.0 by sodium carbonate, and water glass is added as a gangue mineral inhibitor in an amount of 2000 g / t. A sodium oleate collector of 600 g / t is added. After aeration and slurry mixing for 5 minutes, fluorite roughing operation is carried out. During the roughing process, the slurry pH is stabilized at 10.0-10.5. This pH range is more conducive to fluorite floating. 300 g / t of sodium oleate collector is added in the scavenging operation. The first two selections use water glass as an inhibitor, and the dosage follows the principle of step-by-step reduction, namely 1000 g / t and 500 g / t. Acidified water glass is used as an inhibitor in further selection, and the dosage is 400 g / t, 200 g / t, and 100 g / t, respectively. After five selection operations, a fluorite concentrate with a CaF2 grade of 70.31% is obtained, and the recovery rate is 52.5%. The pH of the slurry of the fluorite-removed tailings was adjusted to a weakly acidic condition of 6-7 by hydrochloric acid, and lithium was further selected using a combined anion and cation collector of sodium oleate + dodecylamine (the ratio of NaOL and DDA was 1:1) at a dosage of 150g / t. Tartaric acid was added as an inhibitor at a dosage of 500g / t. The scavenging operation was halved compared to the roughing collector. After one blank selection, a lithium mica concentrate with a Li2O grade of 1.15% was obtained.

[0054] As shown in Table 2, while the conventional fluorite removal and lithium selection process achieves good fluorite and lepidolite separation performance, producing metallurgical-grade fluorite with a CaF2 grade of 70.31% and a recovery rate of 52.5%, and a lepidolite concentrate with a Li2O grade of 1.15% and a recovery rate of 60.1%, the overall beryllium recovery is very poor. BeO is dispersed and lost in the fluorite concentrate, lepidolite, and tailings, without being effectively recovered. Instead, it is concentrated in the lepidolite concentrate, significantly increasing the pollution risk of beryllium-containing wastewater and solid waste generated in the subsequent lithium smelting process, as well as the production cost of solid beryllium, resulting in a serious waste of resources. Furthermore, adjusting the slurry pH to the weakly acidic environment for mica flotation requires high acid consumption, resulting in high reagent costs and causing equipment corrosion.

[0055] Table 1 Main mineral composition of a fluorite tailing in Hunan

[0056]

[0057] Table 2 Comparative Example 1 Flotation closed circuit test results

[0058]

[0059] Example 1

[0060] 0.125 mol of lead nitrate was added to 1 L of 1.0 mol / L benzohydroxamic acid solution under stirring, and the mixture was reacted for 3 minutes to obtain the metal organic complex collector.

[0061] The preparation of the mixed alkali and causticized starch inhibitor in the following specific examples is as follows:

[0062] 5 g of sodium carbonate and sodium hydroxide were weighed separately and placed in a beaker, water was added until the total weight of the solution was 100 g, and the mixture was thoroughly mixed under stirring to obtain the mixed alkaline solution.

[0063] 1 g of caustic soda and 5 g of soluble starch were weighed separately and placed in a beaker. Water was added to a total weight of 100 g of the solution. The solution was placed in a constant temperature magnetic stirring water bath and stirred at a constant temperature and uniform speed at 50°C for 30 minutes. After being fully dissolved, a yellow transparent liquid was obtained. The causticized starch inhibitor was obtained after cooling.

[0064] This process was used to treat a fluorite tailings in Hunan Province. The flotation feed concentration was controlled at about 45wt.%. First, the pH of the pulp was adjusted to 11.0 with mixed alkali. 300g / t of metal-based complex and 200g / t of sodium oleate were added as collectors for the co-enrichment of fluorite and beryllium minerals. After aeration and stirring for 5 minutes, mixed flotation was performed to obtain a mixed coarse concentrate. 150g / t of metal-based complex and 100g / t of sodium oleate were added during scavenging. No reagents were added during the concentrating operation. The foam products obtained from the two blank concentrating steps were the mixed concentrate of fluorite and beryllium minerals. For the mixed concentrate, sodium carbonate was added to re-slurry to a pH of about 9.5, 150 g / t of causticized starch as an inhibitor and 50 g / t of sodium oleate collector were added (compared to the addition of reagents to the mixed concentrate), and after aeration and slurrying for 5 minutes, the fluorite and beryllium minerals were separated. The fluorite floated up with the foam product into the concentrate, and the beryllium minerals were suppressed and entered the tailings; 25 g / t of sodium oleate was added for scavenging, and the scavenged tailings were beryllium concentrate; further concentrating was carried out using acidified water glass (prepared with reference to Comparative Example 1) as an inhibitor, with the dosages of 500 g / t and 250 g / t, respectively, and concentrating twice to obtain a metallurgical-grade fluorite concentrate product. For the tailings of mixed flotation, activator lead nitrate 400g / t, inhibitor sodium hexametaphosphate 100g / t, collector sodium oleate 1200g / t and foaming agent 2# oil 20g / t were added in sequence. After aeration and slurry mixing for 5 minutes, the lepidolite operation was carried out; sodium oleate 600g / t was added during scavenging; and the lepidolite concentrate product was obtained through blank selection.

[0065] As shown in Tables 3 and 4, the new method for treating fluorite tailings not only ensures the effective recovery of fluorite and lepidolite, but also allows for the partial recovery of beryllium, producing a beryllium concentrate with a BeO grade of 2.06% and a recovery rate of 42.31%. Furthermore, the new method produces even better recovery rates for fluorite and lepidolite concentrates: the fluorite concentrate has a CaF2 grade of 79.58% and a recovery rate of 57.54%, and the lepidolite concentrate has a Li2O grade of 1.24% and a recovery rate of 68.79%, significantly improving both the grade and recovery of the concentrates. A collector system combining metal-based complexes and fatty acids can effectively achieve the simultaneous enrichment of multiple beryllium minerals. While not capturing lepidolite, it preferentially floats beryllium minerals along with fluorite to produce a mixed concentrate with a BeO grade of 1.04% and a CaF2 grade of 56.87%. Causticized starch exhibits strong selectivity, enabling targeted chelation of metal-active particles on the surface of beryllium minerals, producing them as a separate beryllium concentrate product. Metal ions effectively activate lepidolite, ensuring a relatively stable alkaline pH throughout the flotation process. Using fatty acids as collectors, the lepidolite can be efficiently recovered by flotation, ultimately achieving the comprehensive resource recovery of fluorite, lithium, and beryllium minerals from fluorite tailings. This technical solution offers simple beneficiation operations, low reagent costs, and strong applicability for fluorite tailings. It provides guidance for the comprehensive recovery of fluorite-associated lithium-beryllium resources and is conducive to further promotion and application.

[0066] Table 3 Indicators of open circuit flotation mixed concentrate in Example 1

[0067]

[0068] Table 4 Flotation closed circuit test results of Example 1

[0069]

Claims

1. A beneficiation method for comprehensive recovery of lithium-beryllium resources in fluorite tailings, characterized by: The following steps are involved: 1) The pH of the fluorite tailings slurry is adjusted to alkaline, and flotation I is performed using a metal organic complex and fatty acids as a composite collector to obtain a mixed concentrate of fluorite and beryllium and tailings I; The metal organic complex is formed by the coordination assembly of a divalent or trivalent metal ion and a hydroxamic acid organic ligand in a molar ratio of 1:(1-12); The divalent or trivalent metal ion is Ca 2+ Mg 2+ 、Zn 2+ 、Fe 2+ , Pb 2+ 、Cu 2+ 、Mn 2+ 、Fe 3+ or Al 3+ At least one of the following; The hydroxamic acid organic ligands are benzohydroxamic acid, salicylic hydroxamic acid, benzenesulfonyl hydroxamic acid, 1-naphthohydroxamic acid and C6~C 12 at least one of the alkyl hydroxamic acids; The fatty acids include at least one of sodium oleate, linoleic acid, naphthenic acid, tall oil, lauric acid, linolenic acid, palmitic acid, stearic acid, ricinoleic acid, and 731 oxidized paraffin soap; 2) After slurrying, the mixed concentrate is subjected to flotation II using causticized starch or acidified water glass as a depressant and fatty acids as a collector to obtain metallurgical-grade fluorite concentrate and tailings II, where tailings II is a beryllium concentrate product; 3) After the tailings I are activated by high-valent metal ions, flotation III is performed using fatty acids as collectors and inorganic phosphates as inhibitors to obtain lithium concentrate.

2. The mineral processing method for comprehensive recovery of lithium-beryllium resources in fluorite tailings according to claim 1, characterized in that: The fluorite tailings contain lithium minerals including lepidolite, and beryllium minerals including at least one of chrysoberyl, berylite, bluestone, beryl and taaffeite.

3. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1, characterized in that: The concentration of the fluorite tailings slurry is controlled at 40-50 wt.%, and the pH is adjusted to 10.0-12.0; wherein, the pH is adjusted using a composite alkali composed of caustic soda and soda ash in a mass ratio of (1-4):

1.

4. The mineral processing method for comprehensive recovery of lithium-beryllium resources in fluorite tailings according to claim 1 or 3, characterized in that: The flotation I includes 1 roughing, 2 cleaning and 1 scavenging; The roughing agent system is as follows: the dosage of the composite collector is 400-800 g / t; the metal organic complex and the fatty acid in the composite collector are measured according to the mass ratio of the hydroxamic acid organic ligand to the fatty acid of (1-4):1; The reagent system for sweeping is as follows: the amount of composite collector used is halved compared to the roughing method; The selection is a blank selection.

5. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1, characterized in that: The mixed concentrate is slurried to a pH of 9.0-10.

0.

6. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1, characterized in that: The causticized starch is obtained by modifying starch with caustic soda; The starch includes at least one of soluble starch, corn starch, potato starch and rice starch.

7. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1, 5 or 6, characterized in that: The flotation II includes 1 roughing, 1 scavenging and 2-3 cleaning; The roughing agent system is as follows: the amount of fatty acids is 50-100 g / t, and the amount of causticized starch is 50-250 g / t; The reagent system for the above-mentioned selection is: acidified water glass is 500-1000 g / t, and is gradually reduced by half with the number of selections; The reagent system for the sweeping selection is that the amount of fatty acids used is halved compared to the roughing selection.

8. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1, characterized in that: The high-valent metal ions include Mg 2+ 、Zn 2+ , Pb 2+ 、Al 3+ or Fe 3+ At least one of the following; The inorganic phosphate includes at least one of sodium metaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

9. The mineral processing method for comprehensive recovery of lithium-beryllium resources from fluorite tailings according to claim 1 or 8, characterized in that: The flotation III includes 1 roughing, 1 cleaning and 2-3 scavenging; The roughing agent system is as follows: the dosage of high-valent metal ions is 200-800 g / t, the dosage of inorganic phosphate is 50-250 g / t, the dosage of fatty acids is 1000-2000 g / t, and the dosage of foaming agent is 10-40 g / t; The pH of the pulp system during the roughing process is stabilized between 9.0 and 10.0; The selection is a blank selection; The drug system for the screening is that the dosage of fatty acids decreases step by step.

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