A composite flotation reagent and its application in lepidolite flotation

Abstract

The present invention discloses a composite flotation reagent and its application in lepidolite flotation. The composite flotation reagent comprises a divalent or higher metal ion activator and a composite collector; the composite collector comprises an amine collector, an alcohol collector, and a hydrocarbon anion collector. Application of the composite flotation reagent in the lepidolite flotation process achieves efficient enrichment of the mica in a neutral system, improves the lepidolite recovery rate, reduces environmental pollution, and reduces equipment corrosion.

Description

Technical Field

[0001] The present invention relates to a composite flotation agent and also to the application of the composite flotation agent in lepidolite flotation, in particular to a composite flotation agent for realizing efficient recovery of lepidolite under near-neutral conditions and the application thereof, belonging to the field of mineral flotation. Background Art

[0002] Lithium, the lightest alkaline earth metal, is the "new energy source of the 21st century." Lithium and its compounds are widely used in batteries, metallurgy, lubricants, ceramics, aerospace, and the nuclear industry. Since the 21st century, with the rapid development of portable electronic devices and electric vehicles, and under the pressure of global climate change, demand for lithium batteries, a green energy metal, has skyrocketed. Lithium consumption has entered a period of rapid growth, particularly driven by new energy vehicles.

[0003] Global lithium reserves are abundant and highly concentrated. Mica minerals are important carrier minerals for lithium, and reserves are also very abundant in my country. However, these mica-based lithium resources often exist in complex co-existing forms and are of low grade. Direct smelting of these resources is economically uneconomical, resulting in low resource utilization. To improve utilization, flotation pre-concentration technology can be used to increase the grade of smelting feed, thereby achieving efficient extraction and utilization of lithium resources.

[0004] Froth flotation is an effective method for impurity removal and purification, achieving high-value utilization of minerals. Due to the negative charge on the surface of lepidolite, traditional lepidolite flotation methods include flotation with amine collectors in strongly acidic systems and flotation with combined anion and cation collectors in alkaline systems. Both strongly acidic and alkaline environments pose a certain degree of harm to equipment and the environment. Furthermore, both methods require the use of large amounts of amine collectors. Amine collectors have high freezing points and poor water solubility, and are typically acidified with hydrochloric acid or acetic acid before use. However, these two acids are difficult to store and inconvenient to prepare. Furthermore, due to the fine particle size and high mud content of lepidolite, traditional amine collector flotation methods easily result in high flotation foam viscosity and difficulty in transportation, severely restricting the flotation separation efficiency and normal production of lepidolite.

[0005] Therefore, it is still of great significance to develop a green agent that can achieve efficient recovery of mica under near-neutral conditions. Summary of the Invention

[0006] In view of the problems existing in the prior art such as high flotation foam viscosity and low separation efficiency caused by the large amount of amine collectors used, and the equipment corrosion caused by the need for the flotation process to be carried out under strong acid and strong alkaline conditions, the first object of the present invention is to provide a composite flotation reagent. The composite flotation reagent utilizes a high-valent metal ion activator with high selectivity for lepidolite minerals in combination with a composite collector including an amine collector, an alcohol collector, and a hydrocarbon anion collector. The composite flotation reagent can achieve efficient recovery of lepidolite minerals under near-neutral conditions and obtain high-grade lepidolite concentrate.

[0007] A second objective of the present invention is to provide a composite flotation reagent for use in lepidolite. This method breaks through the classic amine collector flotation system used in mica mineral processing, achieving efficient enrichment of mica in a neutral system, reducing environmental pollution and equipment corrosion. Furthermore, this method simplifies the process and reduces reagent costs.

[0008] In order to achieve the above technical objectives, the present invention provides a composite flotation reagent comprising a divalent or higher metal ion activator and a composite collector; the composite collector comprises an amine collector, an alcohol collector and a hydrocarbon anion collector.

[0009] The technical solution of the present invention is to utilize the synergistic effect of a divalent or higher metal ion activator and a composite collector. During the flotation process of lepidolite, due to the unique strong negative charge micro-region-weak positive charge micro-region dual action sites on the mica surface, the use of divalent metal ions as activators can take precedence over the surface of the lepidolite mineral, fill negative electron holes, and increase the zeta potential of the quartz surface. At the same time, since divalent or higher metals are used as activators, more active sites can be provided for the subsequent adsorption of the composite collector compared to low-valent metal ions, promoting the adsorption of anions of the composite collector of the present invention on the mineral surface, and improving the adsorption capacity of cations on the mineral surface, thereby strengthening the flotation of lepidolite. The composite flotation agent of the present invention reduces the amount of traditional cationic amine collectors, achieves efficient enrichment of lepidolite in a neutral system, replaces conventional strong acid or strong base flotation technology, reduces corrosiveness, and improves safety.

[0010] The three types of composite collectors used in the present invention exhibit significant synergistic effects. Amine collectors are traditional mica flotation collectors and can interact with lepidolite through electrostatic interactions and hydrogen bonds. Alcohols, as auxiliary collectors, are adsorbed on the lepidolite surface through hydrogen bonds and hydrophobic interactions with the tail chains of the primary collectors, enhancing its surface hydrophobicity, improving foam performance, and increasing flotation recovery and grade. Hydrocarbon anions can act on the lepidolite surface using metal ions as adsorption bridges, forming a stable, rigid adsorption layer and thus improving flotation recovery.

[0011] As a preferred solution, the divalent or higher metal ion activator is Mg 2+ , Ca 2+ , Pb 2+ 、Fe 3+ At least one of them.

[0012] As a preferred solution, the composite collector comprises an amine collector, an alcohol collector, and a hydrocarbon anion collector in a mass ratio of (1-2):(3-5):(40-60). If the amine collector is too high in the composite collector, the selectivity of the composite collector will deteriorate, resulting in a low concentrate grade. If the amine collector is not added, the collection capacity of the composite collector will be weak, resulting in a low concentrate recovery rate. If the amount of hydrocarbon anion collector is too low, the concentrate recovery rate will be low.

[0013] As a preferred solution, the structural formula of the amine collector is RNH2, wherein R is C 10 ~C 19 The amine collector in the present invention is a primary amine, which is mainly adsorbed on the surface of lepidolite by electrostatic action, making the mineral surface hydrophobic, thereby achieving separation from the gangue mineral.

[0014] As a preferred solution, the alcohol collector has the general structural formula of R'OH, wherein R' is C8~C 14 A straight-chain alkyl group or a branched-chain alkyl group.

[0015] As a preferred embodiment, the hydrocarbon anion collector is selected from at least one of long-chain fatty acid compounds, long-chain hydrocarbon sulfate compounds, and long-chain hydrocarbon sulfonic acid compounds. Among these, the most commonly used long-chain fatty acid collectors include sodium oleate, tall oil, and oxidized paraffin soap; common long-chain hydrocarbon sulfate compounds include sodium lauryl sulfate and sodium hexadecyl sulfate; and common long-chain hydrocarbon sulfonic acid compounds include sodium lauryl sulfate and sodium petroleum sulfonate.

[0016] As a preferred solution, the molar ratio of the activator to the hydrocarbon anion collector in the composite collector is 1:(2-4). In the technical solution of the present invention, the molar ratio of the activator to the hydrocarbon anion in the composite collector will directly affect the recovery rate of lepidolite. Too high or too low a molar ratio will affect the recovery rate of lepidolite. If the molar ratio is too high, that is, the concentration of the activator is too high, the metal ions may react with the hydrocarbon anions to form insoluble precipitates, thereby consuming a large amount of the composite collector, reducing the opportunity for the collector to interact with the lepidolite surface, and resulting in a decrease in the recovery rate of lepidolite; and if the molar ratio is too low, that is, the concentration of the hydrocarbon anion is too high, the composite collector may form hydrophilic multilayer adsorption on the mica surface, thereby reducing the hydrophobicity of the mineral surface and affecting the collection of lepidolite.

[0017] The present invention also provides an application of a composite flotation agent in lepidolite. The lepidolite flotation process comprises the following steps: grinding and slurrying the lepidolite ore to obtain slurry; desludging the slurry, adding the composite flotation agent, and performing flotation separation to obtain lepidolite concentrate and flotation tailings.

[0018] As a preferred solution, the grinding process is such that the mass of the minerals meeting the fineness of -200 mesh accounts for 55-65%. Grinding the minerals to an appropriate particle size allows the minerals to be mechanically separated from the gangue minerals, which is beneficial to the subsequent flotation separation process.

[0019] As a preferred solution, the slurry is adjusted to adjust the mass percentage concentration of the ore slurry to 35-45% and the pH to 7-10. More preferably, the pH is 7.5-8.5.

[0020] As a preferred solution, desliming is performed by allowing the pellets to stand for three times, each cycle lasting 3 to 5 minutes. Desliming by allowing the pellets to stand for three times can improve flotation and filtration performance. Under certain flotation conditions, an optimal particle size composition exists. Flotation at this particle size composition maximizes concentrate yield and overall flotation efficiency, while also significantly improving subsequent concentrate filtration.

[0021] As a preferred solution, the flotation separation includes one roughing separation and at least one scavenging separation.

[0022] As a preferred solution, the flotation reagent system for roughing is: the amount of activator relative to the original ore is 30-60g / t, and the amount of composite collector relative to the original ore is 150-200g / t.

[0023] As a preferred solution, the flotation reagent system for scavenging is: the amount of activator relative to the original ore is 15-30g / t, and the amount of composite collector relative to the original ore is 75-100g / t.

[0024] As a preferred solution, the pH value of the slurry after desliming is about 7.6, the pH value of the system remains basically unchanged after the addition of the activator, and the pH value of the system is about 8 after the addition of the composite collector. That is, the entire lepidolite flotation process of the present invention can be carried out in a near-neutral environment, reducing corrosion to the equipment.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The present invention breaks through the classic amine collector flotation system for mica mineral beneficiation. Based on the unique ion exchange effect on the surface of mica minerals, a metal ion activator with high selectivity for lepidolite minerals is invented. Then, a composite collector is used to achieve efficient capture of lepidolite minerals.

[0027] 2) The technical solution provided by the present invention adopts a composite flotation agent to achieve efficient enrichment in a mica neutral system, reduce pollution to the environment, and reduce corrosion to equipment.

[0028] 3) The composite flotation reagent of the technical solution provided by the present invention replaces the amine collector flotation method by promoting the hydrocarbon anion collector in the composite collector through the activator, greatly reducing the amount of amine collector used, effectively avoiding the shortcomings of the amine collector configuration and use process, greatly simplifying the reagent system and process flow, reducing the reagent cost, and completely solving the problems of high viscosity and poor rheology of lepidolite flotation foam. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of the flotation method of Examples 1 and 2 of the present invention.

[0030] Figure 2 This is a flow chart of the flotation method of Examples 3 to 5 of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by professionals in this field without making creative efforts are still within the scope of protection of the present invention.

[0032] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0033] The technical route adopted in the embodiment is: grinding - adding flotation reagents - roughing - scavenging flotation process.

[0034] Example 1

[0035] In order to make a clearer comparison, this example uses pure lepidolite mineral with a purity of >95% (chemical composition see Table 1) as the research object, and examines the flotation performance of the composite flotation agent at different pH values ​​by changing the pH value of the pulp. The test process is as follows: Figure 1 shown.

[0036] Table 1 Chemical composition analysis of pure minerals of lepidolite / %

[0037]

[0038] In this embodiment, the divalent or higher metal ion activator is Mg 2+The composite collector is composed of 1 part, 3 parts and 40 parts by mass of dodecylamine, sodium oleate and octanol, and is configured with pure water to form a 0.01 mol / L aqueous solution for use; the molar ratio of the activator to the hydrocarbon anion collector in the composite collector is 1:3.

[0039] The specific experimental operation process of the flotation process is as follows: pure lepidolite minerals are crushed with a crusher and sieved with a standard sieve to obtain particles with a particle size of 0.074-0.037 mm; for each group of experiments, 2 g of the sieved lepidolite concentrate is weighed and poured into a 40 mL flotation tank, 35 mL of deionized water is added, and NaOH / HCl (mass concentration 2%) is added to adjust the flotation system to a specific pH (4, 6, 7, 8, 10, 11) and stirred for 2 minutes. -4 mol / L concentration standard magnesium chloride was added, stirred for 1 min, and then the - 4 mol / L concentration standard composite collector was added, and the pH was adjusted to the specified value (4, 6, 7, 8, 10, 11), followed by stirring for 3 minutes; scraping foam was started for 2 minutes, and the concentrate was scraped into the concentrate basin along with the foam, and the tailings remained in the flotation tank. The concentrate and tailings were filtered and dried, and then weighed separately. The recovery rate was calculated and summarized in Table 2.

[0040] Table 2 Recovery of lepidolite concentrate at different pH values

[0041]

[0042] As shown in Table 2, the composite flotation reagent used in this embodiment has a high recovery rate of lepidolite when the pH is 7-10, indicating that the composite flotation reagent is suitable for use in a near-neutral environment.

[0043] Example 2

[0044] In order to make a clearer comparison, this example uses pure lepidolite mineral with a purity of >95% (the mineral chemical composition is the same as in Example 1) as the research object, and examines the flotation performance of composite flotation reagents under different ratios by changing the reagent ratio. The test process is as follows: Figure 1 shown.

[0045] In this embodiment, the divalent or higher metal ion activator is Mg 2+ The composite collector is made of octadecylamine, sodium dodecylsulfonate and decanol in 2 parts, 4 parts and 55 parts by mass, and is prepared into a 0.01 mol / L aqueous solution with pure water for use; the total concentration of the divalent metal ion activator and the composite collector is 5×10 -4 mol / L.

[0046] The specific experimental operation process is as follows: pure lepidolite minerals were crushed with a crusher and sieved with a standard sieve to obtain particles with a particle size of 0.074-0.037 mm; in each group of experiments, 2 g of the sieved lepidolite concentrate was weighed and poured into a 40 mL flotation tank, 35 mL of deionized water was added, and NaOH (mass concentration 2%) was added to adjust the pH value of the flotation system to 8 and stirred for 2 minutes. The total concentration of the activator and the composite collector was fixed at 5×10 -4 mol / L, flotation reagents were added in sequence according to a certain molar ratio (activator: hydrocarbon anion collector in the composite collector = 2:1, 1:2, 1:3, 1:4, 1:5), and the time interval between the addition of the two reagents was 1 min. After the addition of the reagents, the pH of the slurry was adjusted to 8 again, and then stirred for 3 min; scraping foam was started for 2 min, and the concentrate was scraped into the concentrate basin along with the foam, and the tailings remained in the flotation tank. The concentrate and tailings were filtered and dried, and then weighed separately. The recovery rate was calculated and summarized in Table 3.

[0047] Table 3 Recovery of lepidolite concentrate at different molar ratios of activator and collector

[0048]

[0049] It can be seen from Table 3 that a molar ratio of the activator to the collector that is too high or too low will lead to a decrease in the recovery rate of lepidolite.

[0050] Example 3

[0051] This example uses a lepidolite mine in Yichun, Jiangxi Province. The raw ore is mainly composed of lepidolite, quartz and feldspar, and the Li2O grade of the raw ore is 0.39%. The test process is as follows: Figure 2 shown.

[0052] The composite collector used contains the following raw materials in parts by weight: 1 part of dodecylamine, 3 parts of dodecyl alcohol, 50 parts of sodium lauryl sulfate, and the activator used is Ca 2+ .

[0053] The specific experimental operation process was as follows: 800g of ore was ground for 3 minutes and 30 seconds, passed through a 40-mesh sieve, and the oversize particles were discarded. The undersize particles were slurried with water to a slurry concentration of approximately 45% and stirred for 2 minutes. The resulting slurry was subjected to three sedimentation desliming processes, with sedimentation times of 5 minutes, 3 minutes, and 3 minutes, respectively, to obtain deslimed slurry and fine mud. Calcium chloride was added to the slurry at a rate of 50g / t and stirred for 1 minute. A composite collector was then added at a rate of 150g / t and stirred for 1 minute before roughing. Calcium chloride was added to the resulting rougher tailings at a rate of 25g / t and stirred for 1 minute. A composite collector was then added at a rate of 75g / t and stirred for 1 minute. This was then subjected to a scavenging process and combined with the rougher product. The resulting mica concentrate and tailings were filtered, dried, and weighed. The recovery rate and Li2O grade of each product were calculated. Specific flotation indicators for each flotation product are shown in Table 4.

[0054] Table 4 Product indicators of a lepidolite mine in Yichun, Jiangxi Province (%

[0055]

[0056] From Table 4, we know that this embodiment uses Ca 2+ The activation process was carried out and the Li2O grade of lepidolite in the concentrate was improved by using dodecylamine, dodecanol and sodium dodecyl sulfate as a composite collector.

[0057] Example 4

[0058] This embodiment uses a lepidolite mine in Jinggangshan, Jiangxi Province. The raw ore is mainly composed of lepidolite, quartz and feldspar. The raw ore Li2O grade is 0.12%. The test process is as follows: Figure 2 shown.

[0059] The composite collector used contains the following raw materials in parts by weight: 1 part of dodecylamine, 3 parts of dodecyl alcohol, 50 parts of sodium lauryl sulfate, and the activator used is Mg 2+ .

[0060] The specific test operation process is as follows: take 500g of ore, grind it for 4min 30s, pass it through a 40-mesh sieve, discard the mineral particles on the sieve, add water to the mineral particles under the sieve to make a pulp, the pulp concentration is about 35%, and stir for 2min; the obtained ore pulp to be processed is subjected to three sedimentation and desliming, with sedimentation times of 5min, 3min and 3min respectively, to obtain deslimed ore pulp and fine mud; magnesium chloride is first added to the ore pulp at a standard of 50g / t, stirred for 1min, and then a composite collector is added at a standard of 200g / t, stirred for 1min, and roughing is carried out; magnesium chloride is first added to the obtained roughing tailings at a standard of 25g / t, stirred for 1min, and then a composite collector is added at a standard of 100g / t, stirred for 1min, and a scavenging is carried out, and the scavenging is combined with the roughing product. Finally, mica concentrate and tailings are obtained, which are filtered, dried and weighed, and the recovery rate is calculated and the Li2O grade of each product is measured. The specific flotation indicators of each flotation product are shown in Table 5:

[0061] Table 5 Product indicators of a lepidolite mine in Jinggangshan, Jiangxi Province (%

[0062]

[0063] As shown in Table 5, this embodiment uses Mg 2+ Ion activation, using dodecylamine, dodecanol, and sodium dodecyl sulfate as a composite collector, can significantly improve the Li2O grade in the resulting lepidolite concentrate compared to the original ore.

[0064] Example 5

[0065] This example uses a lepidolite mine in Ganzhou, Jiangxi Province. The raw ore is mainly composed of lepidolite, quartz and feldspar, and the Li2O grade of the raw ore is 0.18%. The test process is as follows: Figure 2 shown.

[0066] The composite collector used contains the following raw materials in parts by weight: 2 parts of dodecylamine, 3 parts of dodecyl alcohol, 40 parts of sodium oleate, and the activator used is Fe 3+ .

[0067] The specific test operation process is as follows: take 500g of ore, grind it for 5 minutes, pass it through a 40-mesh sieve, discard the mineral particles on the sieve, add water to the mineral particles under the sieve to adjust the slurry concentration to about 44%, and stir for 2 minutes; the obtained slurry to be processed is subjected to three sedimentation and desliming, with sedimentation times of 5 minutes, 3 minutes and 3 minutes respectively, to obtain deslimed slurry and fine mud; add activator to the slurry at a standard of 30g / t, stir for 1 minute, then add composite collector at a standard of 150g / t, stir for 1 minute, and perform roughing; add activator to the obtained roughing tailings at a standard of 15g / t, stir for 1 minute, then add composite collector at a standard of 75g / t, stir for 1 minute, perform a scavenging, and combine with the roughing product. Finally, mica concentrate and tailings are obtained, which are filtered, dried and weighed, and the recovery rate is calculated and the Li2O grade of each product is measured. The specific flotation indicators of each flotation product are shown in Table 6:

[0068] Table 6 Product indicators of a lepidolite mine in Ganzhou, Jiangxi Province (%

[0069]

[0070] From Table 6, we know that Fe 3+ After activation, the Li2O grade in the obtained lepidolite concentrate was significantly improved compared with the original ore, using dodecylamine, dodecanol and sodium oleate as a composite collector for capture.

[0071] Comparative Example 1

[0072] The only difference between Comparative Example 1 and Example 5 is that no activator is added.

[0073] The specific flotation indicators of each flotation product are shown in Table 7:

[0074] Table 7 Product indicators of a lepidolite mine in Ganzhou, Jiangxi Province (%

[0075]

[0076] As shown in Table 7, in this comparative example, no metal ion activator was added and the composite collector was used directly for collection. The yield of the obtained lepidolite concentrate was low and the Li2O grade was low.

[0077] Comparative Example 2

[0078] The only difference between Comparative Example 2 and Example 5 is that the amount of dodecylamine in the composite collector is increased to 20 parts.

[0079] The specific flotation indicators of each flotation product are shown in Table 8:

[0080] Table 8 Product indicators of a lepidolite mine in Ganzhou, Jiangxi Province (%

[0081]

[0082] As shown in Table 8, the comparative example increases the amount of amine collector in the composite collector, and the yield of the obtained lepidolite concentrate is higher, but the Li2O grade is lower, indicating that the lepidolite concentrate is seriously entrained.

[0083] Through the above examples, it can be found that the present invention can effectively recover mica minerals under neutral conditions without the need for additional acid or alkali, with less entrainment, high flotation efficiency, little environmental pollution, and light corrosion to equipment, which is of great significance for achieving green flotation of mica.

Claims

1. A lepidolite composite flotation reagent, characterized in that: The invention comprises a divalent or higher metal ion activator and a composite collector; the composite collector comprises an amine collector, an alcohol collector and a hydrocarbon anion collector; The divalent or higher metal ion activator is Mg 2+ , Ca 2+ , Pb 2+ 、Fe 3+ At least one of the following; The composite collector is composed of an amine collector, an alcohol collector and a hydrocarbon anion collector in a mass ratio of (1-2): (3-5): (40-60); The molar ratio of the activator to the hydrocarbon anion collector in the composite collector is 1:(2-4).

2. A lepidolite composite flotation reagent according to claim 1, characterized in that: The general structural formula of the amine collector is RNH2, wherein R is C 10 ~C 19 A straight-chain alkyl group or a branched-chain alkyl group; The general structural formula of the alcohol collector is R'OH, wherein R' is C8~C 14 A straight-chain alkyl group or a branched-chain alkyl group; The hydrocarbon anion collector is selected from at least one of long-chain fatty acid compounds, long-chain hydrocarbon sulfuric acid compounds and long-chain hydrocarbon sulfonic acid compounds.

3. The use of a lepidolite composite flotation reagent as claimed in claim 1 or 2, characterized in that: The lepidolite flotation process comprises the following steps: grinding and slurrying the lepidolite ore to obtain slurry; desludging the slurry, and then adding the composite flotation agent to perform flotation separation to obtain lepidolite concentrate and flotation tailings.

4. The use according to claim 3, characterized in that: The grinding is to meet the fineness of -200 mesh, and the mass of the minerals accounts for 55-65%; The slurry adjustment is to adjust the mass percentage concentration of the ore slurry to 35-45% and the pH to 7-10.

5. The use according to claim 3, characterized in that: The desludging treatment method is to let it stand for 3 times, and the time for each time is 3 to 5 minutes.

6. The use according to claim 4 or 5, characterized in that: The flotation separation includes one roughing separation and at least one scavenging separation; The flotation reagent system for roughing is as follows: the dosage of activator relative to the original ore is 30-60 g / t, and the dosage of composite collector relative to the original ore is 150-200 g / t; The flotation reagent system for the scavenging selection is as follows: the amount of activator relative to the original ore is 15-30g / t, and the amount of composite collector relative to the original ore is 75-100g / t.

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