Preparation method and application of lepidolite mineral flotation inhibitor
By preparing citconic anhydride and sulfamic acid copolymer monomers and chitosan to form a stable inhibitory layer, the problem of insufficient selectivity of existing lithium mica mineral flotation inhibitors is solved, and the recovery rate of lithium mica and the selectivity of flotation process is improved.
Patent Information
- Application Number
- CN202510680696.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2025-08-19
AI Technical Summary
The existing lithium mica mineral flotation inhibitors are poor in selective separation of lithium mica from other minerals, resulting in a low lithium recovery rate. The existing inhibitors lack the adsorption selectivity of lithium mica, affecting the selective separation effect of flotation.
The reaction of citconic anhydride and sulfamic acid is used to form a copolymer monomer, which is complexed with chitosan, and acts with the surface of lithium mica through chemical bonds or adsorption layers to form a stable inhibitory layer, adjust the surface charge properties, reduce the inhibition of other minerals, and improve the recovery rate of lithium mica.
It improves the inhibition effect and recovery rate of lithium mica, enhances the selectivity of the flotation process, reduces the impact on other minerals, and improves the stability and efficiency of the flotation process.
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Figure CN120502433A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of flotation technology, and in particular to a preparation method and application of a lepidolite mineral flotation inhibitor. Background Art
[0002] Lepidolite is a lithium-containing aluminum silicate mineral belonging to the mica family. Mica ore typically contains a variety of mineral impurities, such as quartz, feldspar, and mica. Flotation can separate lepidolite from other minerals, thereby improving the lithium grade in the lepidolite concentrate. Commonly used reagents for lepidolite flotation include collectors, frothers, pH adjusters, and flotation depressants. Lepidolite beneficiation traditionally uses coconut amine as a collector, although mixed anion and cation reagents are also used. A closed-circuit process consisting of one roughing, two finishing, and two scavenging steps is employed, with the addition of large amounts of pH adjusters and depressants. The recovery rate is between 60-70%.
[0003] The flotation inhibitors in the prior art include polysaccharides and polymer inhibitors. The specific preparation method is to mix the polysaccharide inhibitor and the polymer inhibitor with water, heat and dissolve them, then add a mixture of inorganic inhibitors, organic small molecule inhibitors and polyphenol inhibitors, and stir until they are completely dissolved. The sugar inhibitors do not have sufficiently strong selectivity for the adsorption of minerals. Compared with inorganic inhibitors, their selectivity is worse. This may make it difficult to accurately suppress the suspension rate of lithium in the flotation of lepidolite minerals, and also have a certain inhibitory effect on other minerals, affecting the selective separation effect of flotation and reducing the lithium recovery rate. Therefore, the present invention provides a preparation method of the lepidolite mineral flotation inhibitor to solve the problems existing in the above-mentioned prior art. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the present invention aims to provide a preparation method and application of a lepidolite mineral flotation depressant.
[0005] A method for preparing a lepidolite mineral flotation depressant comprises the following steps: S1: Preparation of citraconic anhydride Itaconic acid, DMF and a dehydrating agent are mixed and heated to reflux, and after the reaction is completed, the refluxed aqueous phase and the dehydrating agent are separated to obtain a crude product, and the dehydrating agent and DMF are removed from the crude product to obtain citraconic anhydride; S2: Preparation of polymer monomers After mixing citraconic anhydride and aminosulfonic acid, deionized water is added, and the temperature is raised to react. Subsequently, the mixture is allowed to stand at room temperature, and the reaction product is subjected to vacuum rotary evaporation to remove the solvent and impurities, and dried to obtain a polymer monomer; S3: Preparation of copolymer The polymer monomer is stirred, and acrylic acid and ammonium persulfate are added dropwise during the stirring process, and the temperature is raised to react to obtain a light yellow liquid. The light yellow liquid is transferred to a separatory funnel, and an extractant is added, followed by adding anhydrous ethanol and vacuum rotary evaporation, and drying to obtain a copolymer; S4: Preparation of Lepidolite Mineral Flotation Depressants Chitosan is dissolved in an acetic acid aqueous solution and stirred, and then ammonium cerium nitrate is added and stirred, and then the copolymer is added and stirred, and then acetone is added after stirring, and the mixture is filtered under reduced pressure. The filter cake is washed with ultrapure water, dried, and crushed to obtain a lepidolite mineral flotation inhibitor.
[0006] Furthermore, step S1 prepares citraconic anhydride, comprising the following steps: S1.1: Mix itaconic acid, DMF, and a dehydrating agent in a mass ratio of 2:(0.8-1):(7-8), heat under reflux for 1-1.5 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product. S1.2: Distill the crude product at 100-120°C, 7 kPa for 1-2 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
[0007] Furthermore, step S2 of preparing the polymer monomer comprises the following steps: S2.1: Mix 1-2 parts by weight of citraconic anhydride and 1.1-2.2 parts by weight of aminosulfonic acid, add 80-100 parts by weight of deionized water, stir magnetically at 200-300 rpm, and heat to 90-95°C. Maintain this temperature for 4-6 hours. S2.2: Then, the mixture was allowed to stand until the room temperature reached 24°C, and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 75-80°C for 5-6 hours to obtain a polymer monomer.
[0008] Furthermore, step S3 of preparing the copolymer comprises the following steps: S3.1: Stir 1-2 parts by weight of the polymer monomer at 200-300 r / min for 10-15 minutes. Add dropwise 0.5-1 parts by weight of acrylic acid and 0.2-0.4 parts by weight of 20 wt% ammonium persulfate during stirring. Then, heat the mixture to 95-100°C and maintain for 2-2.5 hours to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system weight of the extractant. Then add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 75-80°C for 2-3 hours to obtain a copolymer.
[0009] Furthermore, step S4 of preparing a lepidolite mineral flotation depressant comprises the following steps: S4.1: Dissolve 0.5-1 parts by weight of chitosan in 70-80 parts by weight of a 1 wt% aqueous acetic acid solution, stirring at 50-60°C for 10-15 minutes, then add 0.05-0.08 parts by weight of ammonium cerium nitrate, stirring for 30-35 minutes, and then add 1-2 parts by weight of the copolymer, stirring for 3.5-4 hours; S4.2: After stirring, adjust the pH value of the system to 9-11 with NaOH, add 2-3 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry at 50-60°C, and crush to obtain a lepidolite mineral flotation inhibitor.
[0010] Furthermore, the dehydrating agent is cumene.
[0011] Furthermore, the extractant is prepared by mixing acetone and ethanol in a volume ratio of 1:3.
[0012] Application of a lepidolite mineral flotation inhibitor to improve the separation efficiency of lepidolite and gangue minerals in the flotation of lepidolite ore Compared with the prior art, the present invention has at least the following beneficial effects: 1. The copolymer monomers generated by the reaction of citraconic anhydride and aminosulfonic acid in the present invention can interact with lithium ion groups on the surface of lepidolite to form stable chemical bonds or adsorption layers. This specific chemical reaction enables the inhibitor to be more effectively adsorbed on the surface of lepidolite, thereby improving the inhibitory effect on lepidolite and reducing the flotation recovery rate of lepidolite. At the same time, it has little effect on other minerals in the lepidolite that do not contain aluminum ions, such as quartz, apatite, and pyrite, thereby improving the selectivity of the flotation process. In addition, the copolymer prepared using the copolymer monomers as raw materials can change the charge properties of the lepidolite surface. By adjusting the electrical properties of the lepidolite surface, the surface charge distribution can be made more uniform, thereby reducing the electrostatic attraction between the lepidolite surface and the collector, further inhibiting the flotation of the lepidolite, and thus improving the recovery rate.
[0013] 2. The present invention adds acrylic acid and ammonium persulfate to copolymer monomers to prepare a polymer. The prepared polymer has good dispersibility and stability, can be evenly dispersed in the slurry, better contact with the surface of lepidolite, form a stable inhibition layer, and thus improve the inhibition effect. At the same time, the copolymer can also adjust the rheological properties and surface properties of the slurry, improve the dispersibility and stability of the slurry, reduce the interference of the ore mud on the flotation of lepidolite, and improve the stability and efficiency of the flotation process.
[0014] 3. The present invention prepares a flotation depressant by compounding a copolymer and chitosan. Chitosan is a natural polysaccharide polymer with abundant active groups such as amino and hydroxyl groups. These groups can chemically adsorb lithium ions on the surface of lepidolite to form a hydrophilic adsorption film. At the same time, the copolymer monomer of citraconic anhydride and aminosulfonic acid and the acrylic acid polymer can also adsorb lithium ions on the surface of lepidolite. Through multi-point adsorption and coverage, a thicker and more stable inhibition layer is formed, thereby more effectively preventing the collector from contacting the lepidolite surface, enhancing the inhibition effect on lepidolite, and improving the recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable one skilled in the relevant art to make and use the present disclosure.
[0016] Figure 1 This is a flow chart of a method for preparing a lepidolite mineral flotation depressant used in an embodiment of the present invention. DETAILED DESCRIPTION
[0017] The following describes in detail a method for preparing a lepidolite mineral flotation depressant provided by the present invention, with reference to the accompanying drawings and specific examples. It is also noted that, for the sake of completeness, the following examples are best and preferred embodiments, and those skilled in the art may employ alternative methods for implementing known techniques. Furthermore, the accompanying drawings are intended only to provide a more detailed description of the embodiments and are not intended to limit the present invention.
[0018] Example 1: A method for preparing a flotation inhibitor of a lepidolite mineral, such as Figure 1 As shown, the following steps are included: S1: Preparation of citraconic anhydride S1.1: Mix itaconic acid, DMF, and dehydrating agent cumene in a mass ratio of 2:0.8:7, heat under reflux for 1 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product; S1.2: Distill the crude product at 100°C, 7 kPa for 1 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
[0019] S2: Preparation of polymer monomers S2.1: Mix 1 part by mass of citraconic anhydride and 1.1 parts by mass of aminosulfonic acid, add 80 parts by mass of deionized water, stir magnetically at 200 rpm, and heat to 90°C, where it is maintained for 4 hours. S2.2: Then, the mixture was allowed to stand at room temperature (24°C), and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 75°C for 5 hours to obtain a polymer monomer.
[0020] S3: Preparation of copolymer S3.1: Stir 1 part by mass of the polymer monomer at 200 r / min for 10 min. Add 0.5 parts by mass of acrylic acid and 0.2 parts by mass of 20 wt% ammonium persulfate dropwise during stirring. The mixture is then heated to 95°C and maintained for 2 h to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system mass of an extractant, which is prepared by mixing acetone and ethanol in a volume ratio of 1:3. Then, add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 75°C for 2 hours to obtain a copolymer.
[0021] S4: Preparation of Lepidolite Mineral Flotation Depressants S4.1: Dissolve 0.5 parts by mass of chitosan in 70 parts by mass of 1 wt% acetic acid aqueous solution, stir at 50°C for 10 minutes, then add 0.05 parts by mass of cerium ammonium nitrate, stir for 30 minutes, then add 1 part by mass of copolymer, and stir for 3.5 hours; S4.2: After stirring, adjust the pH value of the system to 9 with NaOH, add 2 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry it at 50°C, and crush it to obtain a lepidolite mineral flotation inhibitor.
[0022] Example 2: A method for preparing a lepidolite mineral flotation inhibitor, such as Figure 1 As shown, the following steps are included: S1: Preparation of citraconic anhydride S1.1: Mix itaconic acid, DMF, and dehydrating agent cumene in a mass ratio of 2:1:8, heat under reflux for 1 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product; S1.2: Distill the crude product at 100°C, 7 kPa for 1 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
[0023] S2: Preparation of polymer monomers S2.1: Mix 2 parts by mass of citraconic anhydride and 2.2 parts by mass of aminosulfonic acid, add 80 parts by mass of deionized water, stir magnetically at 200 rpm, and heat to 90°C, where it is maintained for 4 hours. S2.2: Then, the mixture was allowed to stand at room temperature (24°C), and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 75°C for 5 hours to obtain a polymer monomer.
[0024] S3: Preparation of copolymer S3.1: Stir 2 parts by mass of the polymer monomer at 200 r / min for 10 min. Add 1 part by mass of acrylic acid and 0.4 parts by mass of 20 wt% ammonium persulfate dropwise during stirring. The mixture is then heated to 95°C and held for 2 h to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system mass of an extractant, which is prepared by mixing acetone and ethanol in a volume ratio of 1:3. Then, add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 75°C for 2 hours to obtain a copolymer.
[0025] S4: Preparation of Lepidolite Mineral Flotation Depressants S4.1: Dissolve 1 part chitosan in 80 parts of 1 wt% acetic acid aqueous solution, stir at 50°C for 10 min, then add 0.08 parts of cerium ammonium nitrate, stir for 30 min, then add 1 part of copolymer, and stir for 3.5 h; S4.2: After stirring, adjust the pH value of the system to 9 with NaOH, add 3 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry it at 50°C, and crush it to obtain a lepidolite mineral flotation inhibitor.
[0026] Example 3: A method for preparing a lepidolite mineral flotation inhibitor, such as Figure 1 As shown, the following steps are included: S1: Preparation of citraconic anhydride S1.1: Mix itaconic acid, DMF, and dehydrating agent cumene in a mass ratio of 2:0.8:7, heat under reflux for 1.5 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product; S1.2: Distill the crude product at 120°C, 7 kPa for 2 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
[0027] S2: Preparation of polymer monomers S2.1: Mix 1 part by mass of citraconic anhydride and 1.1 parts by mass of aminosulfonic acid, add 80 parts by mass of deionized water, stir magnetically at 300 rpm, and heat to 95°C, where it is maintained for 4 hours. S2.2: Then, the mixture was allowed to stand until it reached room temperature (24°C), and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 80°C for 6 hours to obtain a polymer monomer.
[0028] S3: Preparation of copolymer S3.1: Stir 1 part by mass of the polymer monomer at 300 r / min for 15 min. Add 0.5 parts by mass of acrylic acid and 0.2 parts by mass of 20 wt% ammonium persulfate dropwise during stirring. The mixture is then heated to 100°C and maintained for 2.5 h to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system mass of an extractant, which is prepared by mixing acetone and ethanol in a volume ratio of 1:3. Then, add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 80°C for 3 hours to obtain a copolymer.
[0029] S4: Preparation of Lepidolite Mineral Flotation Depressants S4.1: Dissolve 0.5 parts by mass of chitosan in 70 parts by mass of 1 wt% acetic acid aqueous solution, stir at 50°C for 15 minutes, then add 0.05 parts by mass of cerium ammonium nitrate, stir for 35 minutes, then add 1 part by mass of copolymer, and stir for 3.5 hours; S4.2: After stirring, adjust the pH value of the system to 11 with NaOH, add 2 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry it at 50°C, and crush it to obtain a lepidolite mineral flotation inhibitor.
[0030] Example 4: A method for preparing a lepidolite mineral flotation inhibitor, such as Figure 1 As shown, the following steps are included: S1: Preparation of citraconic anhydride S1.1: Mix itaconic acid, DMF, and dehydrating agent cumene in a mass ratio of 2:0.8:7, heat under reflux for 1 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product; S1.2: Distill the crude product at 100°C, 7 kPa for 1 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
[0031] S2: Preparation of polymer monomers S2.1: Mix 1 part by mass of citraconic anhydride and 1.1 parts by mass of aminosulfonic acid, add 80 parts by mass of deionized water, stir magnetically at 300 rpm, and heat to 90°C, where it is maintained for 4 hours. S2.2: Then, the mixture was allowed to stand at room temperature (24°C), and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 75°C for 6 hours to obtain a polymer monomer.
[0032] S3: Preparation of copolymer S3.1: Stir 1 part by mass of the polymer monomer at 200 r / min for 10 min. Add 0.5 parts by mass of acrylic acid and 0.2 parts by mass of 20 wt% ammonium persulfate dropwise during stirring. The mixture is then heated to 95°C and maintained for 2 h to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system mass of an extractant, which is prepared by mixing acetone and ethanol in a volume ratio of 1:3. Then, add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 80°C for 3 hours to obtain a copolymer.
[0033] S4: Preparation of Lepidolite Mineral Flotation Depressants S4.1: Dissolve 0.8 parts by mass of chitosan in 70 parts by mass of 1 wt% acetic acid aqueous solution, stir at 50°C for 10 minutes, then add 0.07 parts by mass of cerium ammonium nitrate, stir for 30 minutes, then add 1.5 parts by mass of copolymer, and stir for 3.5 hours; S4.2: After stirring, adjust the pH value of the system to 10 with NaOH, add 2 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry it at 50°C, and crush it to obtain a lepidolite mineral flotation inhibitor.
[0034] Comparative Example 1: Comparative Example 1 is a commercially available flotation depressant.
[0035] Comparative Example 2: Compared with Example 1, the difference of Comparative Example 2 is that citraconic anhydride is not added in step S2.1. Specifically, "S2.1: add 1.1 parts by mass of aminosulfonic acid to 80 parts by mass of deionized water, stir magnetically at a speed of 200 r / min, and heat to 90°C, and maintain this temperature for 4 hours." The other steps remain unchanged, and the prepared lepidolite mineral flotation inhibitor is recorded as Comparative Example 2.
[0036] Comparative Example 3: Compared with Example 1, the difference of Comparative Example 3 is that acrylic acid is not added in step S3.1. Specifically, "S3.1: 1 part by mass of the polymer monomer is stirred at a speed of 200 r / min for 10 minutes, and 0.2 parts by mass of 20wt% ammonium persulfate is added dropwise during the stirring process, and then the temperature is raised to 95°C and kept warm for 2 hours to obtain a light yellow liquid." The other steps remain unchanged, and the prepared lepidolite mineral flotation inhibitor is recorded as Comparative Example 3.
[0037] Comparative Example 4: Compared with Example 1, the difference of Comparative Example 4 is that chitosan is not added in step S4.1. Specifically, "S4.1: 70 parts by mass of 1 wt% acetic acid aqueous solution are stirred at 50°C for 10 minutes, and then 0.05 parts by mass of ammonium cerium nitrate are added and stirred for 30 minutes, and then 1 part by mass of copolymer is added and stirred for 3.5 hours." The other steps remain unchanged, and the prepared lepidolite mineral flotation inhibitor is recorded as Comparative Example 4.
[0038] The materials of Examples 1-4 and Comparative Examples 1-4 were added into the lepidolite frame flotation process in an amount of 1 kg / t. The lithium recovery rates were calculated as shown in Table 1.
[0039] Table 1 Recovery rate (%) Example 1 94.3 Example 2 94.1 Example 3 94.5 Example 4 94.2 Comparative Example 1 88.6 Comparative Example 2 85.2 Comparative Example 3 89.2 Comparative Example 4 84.7 As can be seen from Table 1, the recovery rates of Examples 1-4 are above 94.1%, while the recovery rate of Comparative Example 2 is 85.2%. The recovery rate of Comparative Example 3 is 89.2%, and the recovery rate of Comparative Example 4 is 84.7%. It can be seen that the flotation depressant prepared from the raw material combination of the present invention has a better flotation inhibitory effect on lepidolite, thereby improving the lithium recovery rate.
[0040] The recovery rate of comparative example 1 of the commercially available product is 88.6%. It can be seen that the flotation depressant prepared by the present invention is more effective than the commercially available product.
[0041] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.
Claims
1. A method for preparing a lepidolite mineral flotation depressant, characterized in that: The steps include: S1: Preparation of citraconic anhydride Itaconic acid, DMF and a dehydrating agent are mixed and heated to reflux, and after the reaction is completed, the refluxed aqueous phase and the dehydrating agent are separated to obtain a crude product, and the dehydrating agent and DMF are removed from the crude product to obtain citraconic anhydride; S2: Preparation of polymer monomers After mixing citraconic anhydride and aminosulfonic acid, deionized water is added, and the temperature is raised to react. Subsequently, the mixture is allowed to stand at room temperature, and the reaction product is subjected to vacuum rotary evaporation to remove the solvent and impurities, and dried to obtain a polymer monomer; S3: Preparation of copolymer The polymer monomer is stirred, and acrylic acid and ammonium persulfate are added dropwise during the stirring process, and the temperature is raised to react to obtain a light yellow liquid. The light yellow liquid is transferred to a separatory funnel, and an extractant is added, followed by adding anhydrous ethanol and vacuum rotary evaporation, and drying to obtain a copolymer; S4: Preparation of Lepidolite Mineral Flotation Depressants Chitosan is dissolved in an acetic acid aqueous solution and stirred, and then ammonium cerium nitrate is added and stirred, and then the copolymer is added and stirred, and then acetone is added after stirring, and the mixture is filtered under reduced pressure. The filter cake is washed with ultrapure water, dried, and crushed to obtain a lepidolite mineral flotation inhibitor.
2. The method for preparing a lepidolite mineral flotation depressant according to claim 1, wherein: Step S1 prepares citraconic anhydride, comprising the following steps: S1.1: Mix itaconic acid, DMF, and a dehydrating agent in a mass ratio of 2:(0.8-1):(7-8), heat under reflux for 1-1.5 h, and after the reaction is complete, separate the refluxed aqueous phase and the dehydrating agent to obtain a crude product. S1.2: Distill the crude product at 100-120°C, 7 kPa for 1-2 h to remove the dehydrating agent and DMF to obtain citraconic anhydride.
3. The method for preparing a lepidolite mineral flotation depressant according to claim 2, wherein: Step S2 is to prepare a polymer monomer, comprising the following steps: S2.1: Mix 1-2 parts by weight of citraconic anhydride and 1.1-2.2 parts by weight of aminosulfonic acid, add 80-100 parts by weight of deionized water, stir magnetically at 200-300 rpm, and heat to 90-95°C. Maintain this temperature for 4-6 hours. S2.2: Then, the mixture was allowed to stand until the room temperature reached 24°C, and the reaction product was subjected to reduced pressure rotary evaporation to remove the solvent and impurities, and dried in a constant temperature drying oven at 75-80°C for 5-6 hours to obtain a polymer monomer.
4. The method for preparing a lepidolite mineral flotation depressant according to claim 3, wherein: Step S3 prepares the copolymer, comprising the following steps: S3.1: Stir 1-2 parts by weight of the polymer monomer at 200-300 r / min for 10-15 minutes. Add dropwise 0.5-1 parts by weight of acrylic acid and 0.2-0.4 parts by weight of 20 wt% ammonium persulfate during stirring. Then, heat the mixture to 95-100°C and maintain for 2-2.5 hours to obtain a light yellow liquid. S3.2: Transfer the light yellow liquid to a separatory funnel and add 50% of the system weight of the extractant. Then add anhydrous ethanol and evaporate under reduced pressure three times. Dry in a constant temperature drying oven at 75-80°C for 2-3 hours to obtain a copolymer.
5. The method for preparing a lepidolite mineral flotation depressant according to claim 4, wherein: Step S4 is to prepare a lepidolite mineral flotation depressant, comprising the following steps: S4.1: Dissolve 0.5-1 parts by weight of chitosan in 70-80 parts by weight of a 1 wt% aqueous acetic acid solution, stirring at 50-60°C for 10-15 minutes, then add 0.05-0.08 parts by weight of ammonium cerium nitrate, stirring for 30-35 minutes, and then add 1-2 parts by weight of the copolymer, stirring for 3.5-4 hours; S4.2: After stirring, adjust the pH value of the system to 9-11 with NaOH, add 2-3 parts by mass of acetone, filter under reduced pressure, wash the filter cake twice with ultrapure water, dry at 50-60°C, and crush to obtain a lepidolite mineral flotation inhibitor.
6. The method for preparing a lepidolite mineral flotation depressant according to claim 5, characterized in that: The dehydrating agent is cumene.
7. The method for preparing a lepidolite mineral flotation depressant according to claim 6, wherein: The extractant was prepared by mixing acetone and ethanol in a volume ratio of 1:
3.
8. An application of a flotation inhibitor for lepidolite minerals, characterized in that: It is applied to the flotation of lepidolite ore to improve the separation efficiency of lepidolite and gangue minerals.