Beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings

Abstract

The invention discloses a beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings, and belongs to the technical field of beneficiation. According to the method, according to the surface characteristic difference of fluorite associated lithium beryllium minerals, firstly, a metal organic complex and fatty acid are adopted as fluorite and beryllium mineral co-enrichment composite collecting agents, fluorite and beryllium minerals are floated preferentially, and then fluorite and beryllium concentrates are further floated and separated through the beryllium mineral inhibition principle; and the bulk flotation tailings are activated by high-valence metal ions and then subjected to lithium flotation, and lithium concentrate is obtained. By means of the method, qualified metallurgical-grade fluorite and lepidolite concentrate with the Li2O grade being 1.2% can be obtained, the CaF2 recovery rate of 55% or above and the Li2O recovery rate of 65% or above can be achieved, meanwhile, beryllium concentrate with the BeO grade being 2.0% and the recovery rate being 40% can be produced, deep comprehensive recovery of fluorite and associated lithium beryllium resources in fluorite tailings is effectively achieved, and the method is suitable for industrial production. And the method has good social value and economic benefit.

Description

Technical Field

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

[0002] In the context of the global transition to renewable energy, lithium resources, as a key raw material in the fields of new energy vehicles and energy storage systems, play a vital role in achieving sustainable development goals. Metallic beryllium is known as a "super metal" and "cutting-edge metal". Due to its special physical and chemical properties, it is widely used in high-precision and cutting-edge fields such as the nuclear industry and aerospace. It is an irreplaceable key material for the development of future high-tech fields.

[0003] In the existing technology, the development of lithium resources is mainly focused on the development of spodumene, which is relatively easy to be selected, and the development of lithium extraction technology from salt lakes, while the beryllium ore beneficiation technology is almost blank, with only a very small number of reports on beryl flotation, which basically remains in the laboratory stage. With the increasing depletion of high-quality single deposits, the efficient development of co-existing lithium-beryllium resources in polymetallic ores has become a technical problem. Taking a polymetallic mine in Hunan Province, my country as an example, its shallow part is a beryllium-containing fluorite deposit, and the deep part is a tin polymetallic co-existing fluorite deposit. The content of associated beryllium mineral BeO in the original ore reaches 0.11%, and there are also lithium mica resources with a Li2O grade of 0.36%. During the rough selection of fluorite, this part of the lithium-beryllium minerals are suppressed by water glass and fall into the tailings, and cannot be effectively recovered. At the same time, this part of the tailings is directly discharged into the tailings pond, which has high tailings disposal costs and high environmental protection pressure, and also causes serious 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, heliotropite Mn8[BeSiO4]6S2, taaffeite MgBeAl4O8 and beryllite H2Be4Si2O9, etc.) are basically aluminosilicate minerals. They all show poor floatability without activation and are difficult to selectively separate. However, it is worth noting that the two have different spatial structures constructed with [SiO4] and [AlO6] as the skeleton, and there are certain differences in the characteristics of broken bonds and surface characteristics during the dissociation process. Fluorite has good floatability and is easily recovered by flotation of fatty acid collectors containing carboxyl -COOH. In the prior art, Chinese patent CN115228599A proposes a method for pre-enrichment of chrysoberyl-type beryllium ore. The method adopts a technical solution of floating and sinking to remove carbonate gangue - desulfurization - floating fluorite to suppress beryllium. However, the overall process is complicated, the grade of 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 beneficiation method for 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 beneficiation method for comprehensive recovery of lithium-beryllium resources in fluorite tailings. The method adopts a process flow of partial mixed preferential flotation, preferentially co-enriches 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 lithium mica concentrate, which truly realizes 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, using metal organic complexes and fatty acids as composite collectors, and performing flotation I 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, wherein the tailings II is a beryllium concentrate product;

[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 ore dressing 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 of metal organic complexes and fatty acid composite collectors and high-selectivity inhibitors, 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 adopts metal organic complexes and fatty acid composite collectors according to the characteristics of the mineral composition and occurrence state of fluorite tailings (the main valuable minerals are fluorite, lepidolite, chrysoberyl, beryllium minerals such as hydroxysilicon beryllite, and the gangue minerals are mainly muscovite, sodium pearl mica, quartz, and feldspar), and can preferentially float fluorite and beryllium minerals in the form of mixed concentrates to achieve synchronous enrichment and recovery, and further adopt starch inhibitors with good chelating and coordination ability with aluminum particles on the surface of beryllium minerals to achieve targeted inhibition of beryllium minerals, thereby obtaining beryllium concentrate products, and then acidified water glass is used as an inhibitor to select 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 inhibit silicate gangue minerals such as kaolinite and chlorite, and the lepidolite concentrate products are obtained by flotation.

[0012] As a preferred solution, the fluorite tailings contain lithium minerals including lepidolite and beryllium minerals including at least one of chrysoberyl, hydroxysilicate beryllite, blue stone, taaffeite and beryl. More specifically, the mass content of silicate minerals such as muscovite in the fluorite tailings is ≥50%, the mass content of BeO is ≥0.26%, the mass content of Li2O is ≥0.6%, and the mass content of CaF2 is 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 sensitive to the pH conditions of the slurry, so the use of soda ash as a buffer can maintain the stability of the pH of the slurry, and can also effectively disperse the negatively charged ore mud on the surface by compressing the double electric 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 conducive to the targeted adsorption of the collector.

[0014] As a preferred solution, the metal organic complex is formed by the coordination assembly of divalent or trivalent metal ions and hydroxamic acid organic ligands in a molar ratio of 1: (1 to 12). The metal organic complex is further preferably formed by the coordination assembly of divalent or trivalent metal ions and hydroxamic acid organic ligands 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, and can achieve the simultaneous capture of various beryllium minerals such as chrysoberyl and beryllium silicate.

[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 embodiment, 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 of C6~C 12 The alkyl hydroxamic acid may be a linear alkyl group or a branched alkyl hydroxamic acid.

[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 rough selection reagent 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 the mass ratio of hydroxamic acid organic ligand and fatty acid (1-4):1. The metal organic complex and fatty acid are further preferably measured according to the mass ratio of hydroxamic acid organic ligand and fatty acid (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 on the solid / liquid interface can be reduced, and the effective recovery of the target beryllium minerals and fluorite can be enhanced.

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

[0021] As a preferred solution, the blank selection is used. The purpose of the blank selection is to remove the gangue minerals that have not been adsorbed by the reagents in the roughing process and floated due to foam entrainment, so as to enhance 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, and the mass content of CaF2 in the mixed concentrate obtained by open-circuit flotation is ≥40%, and the mass content of BeO is ≥1.0%.

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

[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. Further preferred is soluble starch, and the mass ratio of caustic soda to soluble starch is 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 1 roughing selection, 1 scavenging selection and 2 to 3 cleaning selections.

[0026] As a more preferred solution, the reagent system of the roughing is (compared with the reagent added to the mixed concentrate): the amount of fatty acids is 50-100 g / t, and the amount of causticized starch is 50-250 g / t. The tailings of the roughing operation are beryllium concentrate, and the foam product is further refined to obtain fluorite concentrate. The amount of causticized starch is further preferably 50-250 g / t.

[0027] As a more preferred solution, the reagent system for the above-mentioned selection is: the dosage of acidified water glass is 500-1000 g / t, and is gradually reduced by half with the number of selections. The dosage 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 that the amount of fatty acids used is halved relative to the roughing selection.

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

[0030] The reagent system for the selection and scavenging in the flotation II process of the present invention is that the dosage of acidified water glass and fatty acids is gradually reduced, and the middlings are returned in sequence. Through the preferred reagent system, metallurgical grade fluorite concentrate CaF2 mass content ≥ 75%, recovery rate not less than 55%, beryllium concentrate BeO mass content ≥ 2.0%, recovery rate not less than 40% can be obtained.

[0031] As a preferred embodiment, 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 solution, 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 the hydrolysis and ionization of this type of inhibitor in an aqueous solution can significantly reduce the adsorption amount of the collector on silicate gangue minerals such as quartz, feldspar, kaolinite, and chlorite by selectively complexing certain metal ions. At the same time, it can be used as a dispersant to increase the steric hindrance effect and electrostatic repulsion between particles, which helps to reduce the agglomeration of mineral particles and improve the flotation efficiency of lithium mica.

[0033] As a preferred solution, the flotation III includes 1 roughing selection, 1 cleaning selection and 2 to 3 scavenging selections.

[0034] As a preferred solution, the roughing agent system is: 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: 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 2# oil is 20-30 g / t.

[0035] As a preferred solution, the pH of the pulp system during the roughing process is stabilized between 9.0 and 10.0. During the roughing process, the pH of the pulp system is stabilized between 9.0 and 10.0. Under this weakly alkaline condition, metal ions are adsorbed on the surface of lepidolite in the form of hydroxyl complexes / metal hydroxide precipitations, 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 system for scanning is: the amount of fatty acids used decreases step by step.

[0038] The lithium mica 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 collector double film or fatty acid-metal ion precipitation can be formed through the coordination of carboxyl groups to active metal particles, so that the lithium mica can be hydrophobically floated. 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, which can significantly improve the foam stability. Through the preferred solution, the lithium mica concentrate has a Li2O mass content of ≥1.2% and a recovery rate of ≥65%.

[0039] The acidified water glass of the present invention is a conventional inhibitor for fluorite selection in the prior art, and is formed by compounding sulfuric acid and water glass in a mass ratio of 1:(1-4), and more preferably 1:(1-2). Compared with single water glass, the acidified water glass has a stronger silicon reduction effect, and can also improve the flotation foam state, strengthen the secondary enrichment effect, and improve the efficiency of fluorite flotation.

[0040] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0041] 1. The technical solution of the present invention applies the idea of ​​"partial mixed priority flotation" to the recovery of lithium beryllium resources in fluorite tailings. Compared with the conventional process of first removing fluorite and then selecting lithium mica, 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 lithium mica 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 with co-enrichment of fluorite and beryllium, and then uses causticized starch with a targeted chelating effect on the surface of beryllium minerals as an inhibitor to achieve efficient separation of the beryllium minerals alone as a concentrate product.

[0043] 3. Compared with the conventional cation / anion system for selecting mica, the technical solution of the present invention adopts metal ion activation flotation technology to achieve effective recovery of lithium mica. 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 the beryllium minerals and fluorite, floating them out and then efficiently separating them, thereby avoiding the risk of beryllium pollution in the production 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, strong adaptability, etc., and truly realizes the effective comprehensive recovery of lithium-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 for 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 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 fineness of the original ore 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., and 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 blue sapphire and beryl, with complex occurrence and great difficulty in sorting.

[0053] Use Figure 2In the defluorite-lithium selection process shown in the figure, the fluorite tailings are adjusted to a pulp pH of 10.0 by sodium carbonate, and water glass is added as a gangue mineral inhibitor in an amount of 2000 g / t, and a sodium oleate collector of 600 g / t is added. After aeration and slurry mixing for 5 minutes, a fluorite roughing operation is carried out. During the roughing process, the pulp pH is stabilized at 10.0-10.5, and this pH range is more conducive to the floating of fluorite; 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 gradually decreasing, which is 1000 g / t and 500 g / t respectively. 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 fluorite-removed tailings were treated with hydrochloric acid to adjust the slurry pH to a weakly acidic condition of 6-7, and further selected lithium with an anion-cation combination collector of sodium oleate + dodecylamine (the ratio of NaOL and DDA was 1:1) at a dosage of 150 g / t. Tartaric acid was added as an inhibitor at a dosage of 500 g / t, and the scavenging operation was halved relative to the roughing collector. After one blank selection, a lithium mica concentrate with a Li2O grade of 1.15% was obtained.

[0054] As can be seen from Table 2, although the conventional fluorite removal-lithium selection process can obtain good fluorite and lithium mica selection indicators, and produce metallurgical grade fluorite with a CaF2 grade of 70.31% and a recovery rate of 52.5%, and lithium mica concentrate with a Li2O grade of 1.15% and a recovery rate of 60.1%, the comprehensive recovery effect of beryllium is very poor. BeO is dispersed and lost in fluorite concentrate, lithium mica and tailings, and is not effectively recovered. It is concentrated in the lithium mica concentrate, which greatly increases the pollution risk of beryllium-containing wastewater and solid waste generated in the subsequent lithium smelting process and the production cost of solid beryllium, resulting in serious waste of resources. At the same time, in the process of adjusting the pH of the slurry to the weakly acidic environment of mica flotation, the acid consumption is large, the reagent cost is high, and it will also cause problems such as equipment corrosion.

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

[0056]

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

[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 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] Weigh 5 g of sodium carbonate and sodium hydroxide respectively and put them into a beaker, add water until the total weight of the solution is 100 g, and mix thoroughly under stirring to obtain the mixed alkaline solution.

[0063] Weigh 1g of caustic soda and 5g of soluble starch respectively and place them in a beaker, add water to make the total weight of the solution 100g, place it in a constant temperature magnetic stirring water bath, stir at a constant temperature and uniform speed at 50°C, react for 30 minutes, and present a yellow transparent liquid after being fully dissolved. After cooling, the causticized starch inhibitor can be obtained.

[0064] The process was used to treat a fluorite tailing in Hunan. The flotation feed concentration was controlled at about 45wt.%. First, the pH of the pulp was adjusted to 11.0 with mixed alkali, and 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 slurry 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 in the scavenging process. No reagents were added in the concentrating operation, and the foam products obtained in the two blank concentrating processes 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 inhibitor causticized starch and 50 g / t of sodium oleate collector (compared with the addition of reagents to the mixed concentrate) were added, and after aeration and slurry stirring for 5 minutes, the fluorite and beryllium minerals were separated, and the fluorite floated up into the concentrate along with the foam product, and the beryllium mineral was suppressed and entered the tailings; 25 g / t of sodium oleate was added for scavenging, and the scavenged tailings were beryllium concentrates; further selection was performed using acidified water glass (prepared with reference to Comparative Example 1) as an inhibitor, and the amounts used were 500 g / t and 250 g / t, respectively, and metallurgical grade fluorite concentrate products were obtained after two selections. For the tailings of mixed flotation, add activator lead nitrate 400g / t, inhibitor sodium hexametaphosphate 100g / t, collector sodium oleate 1200g / t and frother 2# oil 20g / t in sequence, aerate and stir for 5 minutes, and then carry out lithium mica operation; add 600g / t sodium oleate in scavenging; and obtain lithium mica concentrate product in blank selection.

[0065] As can be seen from Tables 3 and 4, the new method for treating fluorite tailings can not only ensure the effective recovery of fluorite and lepidolite, but also take into account the recovery of part of beryllium, and produce a beryllium concentrate product with a BeO grade of 2.06% and a recovery rate of 42.31. At the same time, the recovery effect of fluorite and lepidolite concentrate produced by the new method is better, with a CaF2 grade of 79.58% and a recovery rate of 57.54% for fluorite concentrate, and a Li2O grade of 1.24% and a recovery rate of 68.79% for lepidolite concentrate. The grade and recovery rate of the concentrate products have been improved to a certain extent. The collector system of metal-based complex + fatty acid can effectively achieve the simultaneous enrichment of multiple beryllium minerals. While not capturing lithium mica, beryllium minerals and fluorite are floated out preferentially to obtain a mixed concentrate with a BeO grade of 1.04% and a CaF2 grade of 56.87%. The causticized starch has strong selectivity and can be produced as a separate beryllium concentrate product by targeted chelation of metal active particles on the surface of beryllium minerals. Metal ions can effectively activate lithium mica. Under the condition that the pH of the slurry in the whole flotation process is in a relatively stable alkaline condition, the lithium mica can be efficiently flotated and recovered with fatty acid as a collector, and finally the comprehensive resource recovery of fluorite, lithium and beryllium minerals in fluorite tailings can be achieved. This technical solution is simple in operation for the beneficiation of fluorite tailings, has low reagent cost and strong applicability, and has guiding significance for the comprehensive recovery of fluorite-associated lithium-beryllium resources, which is conducive to further promotion and use.

[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, Features: The following steps are involved: 1) adjusting the pH of the fluorite tailings slurry to alkaline, using metal organic complexes and fatty acids as composite collectors, and performing flotation I to obtain a mixed concentrate of fluorite and beryllium and tailings I; 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, wherein the 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. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: The fluorite tailings contain lithium minerals including lepidolite, and beryllium minerals including at least one of chrysoberyl, berylite, blue stone, beryl and taaffeite.

3. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: 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.

4. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: The metal organic complex is formed by coordination and 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 ligand is benzohydroxamic acid, salicylic hydroxamic acid, benzenesulfonyl hydroxamic acid, 1-naphthohydroxamic acid and C 6 ~C 12 at least one of the alkyl hydroxamic acids; 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.

5. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1 or 4, Features: The flotation I includes 1 roughing, 2 cleaning and 1 scavenging; The reagent system for the roughing selection 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 and the fatty acid of (1-4):1; the reagent system for the sweeping selection is as follows: the dosage of the composite collector is halved relative to the roughing selection; The selection is a blank selection.

6. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: The mixed concentrate is slurried to a pH value of 9.0 to 10.

0.

7. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: 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.

8. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, 6 or 7, Features: The flotation II includes 1 roughing, 1 scavenging and 2-3 cleaning; The reagent system for roughing is as follows: the dosage of fatty acids is 50-100 g / t, and the dosage of causticized starch is 50-250 g / t; the reagent system for fine selection is as follows: the dosage of acidified water glass is 500-1000 g / t, and is gradually halved with the number of fine selections; the reagent system for scavenging is as follows: the dosage of fatty acids is halved relative to that of roughing.

9. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1, Features: 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.

10. A beneficiation method for comprehensive recovery of lithium beryllium resources in fluorite tailings according to claim 1 or 9, Features: 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 slurry system during the roughing process is stabilized between 9.0 and 10.0; The selection is a blank selection; The drug system for the scanning is that the dosage of fatty acids decreases step by step.

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