A boron flotation separation method

Abstract

The invention discloses a boron flotation separation method. A boron complex flotation agent with high selectivity of boron complexing function and foaming and flotation properties is prepared, and a complex flotation method is adopted to separate and enrich boron from a boron-containing solution. The complex flotation agent has good selectivity for boron, a wide range of application for boron content, is not affected by concentrated salt, has good applicability to conventional solutions, does not need to specially adjust the pH value of the solution, has good flotation performance, high boron recovery rate, can be recycled after regeneration, and has no secondary pollution. The complex flotation separation process is convenient to operate, the processing scale is flexible and easy to expand, and the cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical engineering, and in particular relates to a boron flotation separation method. Background Art

[0002] At present, the main methods for separating boron from aqueous solutions are precipitation, flotation, electrodialysis, reverse osmosis, extraction and adsorption. The precipitation method is to add strong acids such as hydrochloric acid or sulfuric acid to the solution to convert boron into boric acid precipitate with lower solubility. This method is suitable for systems with high boron content. After precipitation separation, a certain concentration of boron will remain in the solution due to the solubility of boric acid. In addition, precipitation separation is inconvenient to operate, and boric acid flotation method was further developed from boron ore flotation method. Guo Guangyuan et al. (Suggestions on Comprehensive Recovery and Utilization of Boric Acid Mother Liquor in Dachaidan Area [J]. Chemical Minerals and Processing, 2011, (4): 31-45.) In view of the current situation that the large amount of boric acid mother liquor discharged in Dachaidan area has caused local salt lake brine and groundwater resources to be polluted, the mother liquor evaporation concentration-cooling crystallization-flotation method is used to separate and recover boric acid. This method solves the problem of precipitation separation, but there is still the problem of dissolving a small amount of boric acid. Electrodialysis uses the selective permeability of ion exchange membranes and potential difference as the driving force to separate boron from the solution. Nagasawa et al. (Utilization of bipolar membrane electrodialysis for the removal of boron from aqueous solution [J]. Industrial & Engineering Chemistry Research, 2011, 50 (10): 6325-6330.) used bipolar membrane electrodialysis to separate and remove boron. When the initial pH was in the range of 2.3 to 12.0, more than 90% of the boron could be removed. However, this method was greatly affected by salt concentration. When the salt concentration of the solution was high, the power required to separate boron was large and the power consumption was high. Reverse osmosis is mainly used to separate boron by selectively penetrating the solvent through a semipermeable membrane to intercept and remove boron from the aqueous solution. In the study of Koseoglu et al. (Boron removal from seawater using high rejection SWRO membranes-impact of pH, feed concentration, pressure, and cross-flow velocity [J]. Desalination, 2008, 227 (1-3): 253-263.), when the pH value is increased to above 10.5, the form of boron in the aqueous solution is converted from boric acid to negatively charged B (OH) -4, which can produce electrostatic repulsion with the negative charge on the surface of the reverse osmosis membrane, and the retention rate of boron on the membrane reaches 98%. When the actual system is processed, the pH value needs to be adjusted to above 10.5, and the scope of application is limited. For example, in the electrolytic removal of boron by magnesium chloride, high alkalinity will cause magnesium precipitation, so this method is not applicable. The extraction method is to use an organic reagent containing hydroxyl and immiscible with water as an extractant to combine with the boron in the aqueous solution to achieve boron separation.Chinese patent CN103031448A discloses a method for pre-enrichment and separation of lithium and boron in salt lake brine by liquid-liquid-liquid three-phase extraction, which adopts extraction by adding an organic extractant and water back extraction to recover the boron therein. This method simultaneously enriches and extracts lithium and boron from salt lake brine with a high magnesium-lithium ratio. However, due to the addition of an organic extractant, secondary pollution may be caused to the system to be purified, and this method is not suitable for systems for removing boron impurities. The adsorption method is applicable to a wide range of boron concentrations and is simple to operate. Chinese patent CN1666813A discloses specifically organic-inorganic composite boron adsorption functional materials and methods for their preparation, as well as adsorption separation of boron in boron-containing solutions. This type of boron adsorption material is suitable for adsorption separation and enrichment of boron in a variety of boron-containing aqueous solutions, and can be recycled and reused after regeneration. However, the method for preparing boron adsorption materials is complex and has high production costs. Summary of the invention

[0003] The object of the present invention is to overcome the deficiencies of the prior art and provide a boron flotation separation method. A boron complex flotation agent is prepared by long-chain alkylation grafting of meglumine, and the boron in the solution is separated by complex flotation. The separation system has good selectivity for boron, a wide range of application for boron content, a high boron recovery rate, and can be recycled after regeneration without secondary pollution.

[0004] The present invention is achieved through the following technical solutions:

[0005] A boron flotation separation method comprises the following steps:

[0006] Step 1, adding meglumine and an alkaline catalyst into an organic solvent, and dispersing them uniformly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.05 to 0.42 mol / L;

[0007] The alkaline catalyst can mainly neutralize a part of the overactive active centers, inhibit cracking, and divide the active components into relatively independent micro-regions, which can improve the selectivity of the hydroxyl group in meglumine during the reaction and is more conducive to the condensation reaction.

[0008] The mass ratio of meglumine to the alkaline catalyst in the first mixture is 1:0.1-0.5;

[0009] Step 2, adding a long-chain alkyl compound to the first mixture for reaction, wherein the molar ratio of the meglumine to the long-chain alkyl compound is 1:0.8-2, the reaction temperature is 50-90° C., and the reaction time is more than 12 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation, and the solid matter is washed and dried to obtain the flotation agent for boron separation;

[0010] Meglumine undergoes a condensation reaction with long-chain alkyl compounds. Taking long-chain alkane bromide as an example, long-chain alkane bromide reacts with the methylamino group of meglumine to remove small molecule HBr, thereby connecting a long carbon chain to the methylamino group in meglumine.

[0011] The long-chain alkyl compound is C 10 ~C 18 Alkylene oxide and / or C 10 ~C 18 of halogenated alkyl;

[0012] Step 3, adding the flotation agent for boron separation obtained in step 2 to the boron-containing solution, performing aeration stirring flotation after reaction and complexation, and collecting the foam to obtain a boron-enriched product; the amount of the flotation agent for boron separation added is 0.5 to 10 times the mass of the boron substance in the boron-containing solution.

[0013] In the above technical solution, the alkaline catalyst is carbonate, KI, KOH, KHCO3, K2O, or MgO.

[0014] In the above technical solution, the carbonate is sodium carbonate and / or potassium carbonate.

[0015] In the above technical solution, the organic solvent is methanol, ethanol, chloroform, dichloromethane or acetone.

[0016] In the above technical solution, the mass ratio of meglumine to the alkaline catalyst in the first mixture is 1:0.4-0.5.

[0017] In the above technical solution, stirring is performed during the reaction process in step 2.

[0018] In the above technical solution, in step 2, the reaction temperature is 40-50°C.

[0019] In the above technical solution, in step 2, the reaction time is more than 48 hours.

[0020] In the above technical solution, in step 2, the solid matter is cleaned by using petroleum ether, dichloromethane, chloroform, water or ethyl acetate solution; preferably ethyl acetate solution;

[0021] Since ethyl acetate has a high polarity, but its solubility is stronger than petroleum ether and weaker than dichloromethane and chloroform, when ethyl acetate is used to wash the solid product, the unreacted monomer can be dissolved without dissolving the target product, making the final product purer.

[0022] In the above technical solution, the volume ratio of water to ethyl acetate in the ethyl acetate solution is 1 to 5:1.

[0023] In the above technical solution, in step 2, the drying temperature used in the drying process is 30-60°C.

[0024] In the above technical solution, the long-chain alkyl compound is C 10 ~C 18 Chloroalkanes, C 10 ~C 18 of bromoalkyl, C 10 ~C 18 More preferably, the long-chain alkyl compound is C 16 ~C 18 Chloroalkanes, C 16 ~C 18 of bromoalkyl, C 16 ~C 18 of iodoalkyl.

[0025] A flotation agent for boron separation, the general structural formula of the flotation agent is as follows:

[0026]

[0027] in,

[0028] R is C 10～18 Long chain alkyl groups;

[0029] Or, R is a hydroxy-substituted C 10～18 of long chain alkyl.

[0030] In the above technical solution, the general structural formula of the flotation agent is as follows:

[0031]

[0032] in,

[0033] R' is C 8～16 of long chain alkyl.

[0034] The above technical scheme also includes step 4, wherein the boron-enriched product in step 3 is washed and then added with pickling liquid to perform a boron analysis process to obtain a flotation agent and a pickling product after analysis; the pH of the boron analysis process is less than 2.

[0035] The pickling solution is a hydrochloric acid solution, a sulfuric acid solution, a nitric acid solution and / or a phosphoric acid solution, and the acid concentration in the pickling solution is 0.01 to 1 mol / L;

[0036] The boron concentration in the pickled product is ≤5.9 g / L.

[0037] The above technical solution further includes step 5, wherein the resolved flotation agent obtained in step 4 is subjected to water washing and alkali solution washing processes to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation;

[0038] The alkali solution is sodium hydroxide solution, potassium hydroxide solution and / or ammonia water, and the alkali concentration in the alkali solution is 0.01-1 mol / L.

[0039] The advantages and beneficial effects of the present invention are:

[0040] The invention provides a boron flotation separation process. A boron complex flotation agent with high selectivity boron complexing function and foaming and flotation properties is prepared by long-chain alkylation grafting of meglumine. The boron in a solution is separated by a complex flotation method. The separation system has good selectivity for boron, a wide range of application for boron content, is not affected by concentrated salt, has good applicability for conventional solutions, does not need to specially adjust the pH value of the solution, has good flotation performance, high boron recovery rate, can be recycled after regeneration, and has no secondary pollution. The complex flotation separation process is convenient to operate, flexible in processing scale, easy to scale up, and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention provides a Fourier transform infrared (FT-IR) spectrum of a boron separation flotation agent (1) prepared in Example 1 of the present invention and a flotation agent (2) after boron complexation after flotation.

[0042] Figure 2 This is a scanning electron microscope image of the flotation agent for boron separation prepared in Example 1 of the present invention.

[0043] Figure 3 Diagram of the complexation process and flotation process in Example 4 of the present invention.

[0044] Figure 4 Removal rate of each component after the flotation process in Example 4 of the present invention.

[0045] Figure 5 The Fourier transform infrared spectra (FT-IR) are of the boron separation flotation agent (1) prepared in Example 5 of the present invention and the flotation agent (2) after boron complexation after flotation.

[0046] Figure 6 This is a scanning electron microscope image of the flotation agent for boron separation prepared in Example 5 of the present invention.

[0047] Figure 7 Removal rate of each component after the flotation process in Example 5 of the present invention.

[0048] Figure 8 This is the mechanism reaction formula of the flotation agent preparation process for boron separation of the present invention.

[0049] Fig. 9 This is the mechanism of the flotation process of the flotation agent for boron separation of the present invention.

[0050] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0052] Embodiment 1

[0053] A method for preparing a flotation agent for boron separation comprises the following steps:

[0054] Step 1, adding 10 g of meglumine and 4 g of Na2CO3 into ethanol, and dispersing them evenly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.26 mol / L;

[0055] Step 2, adding 20g of 1-bromooctadecane to the first mixture for reaction at a reaction temperature of 50°C for 96 hours; after the reaction, performing rotary evaporation on the reaction product, washing the obtained solid matter with deionized water, and drying at 40°C for 24 hours to obtain the flotation agent for boron separation.

[0056] Step 3, complex flotation separation of boron: add 5g of the flotation agent for boron separation to 500mL of magnesium chloride solution with a boron concentration of 0.01mol / L, stir for 10h, pour into a flotation tank, bubbling at a speed of 1400r / min, float until the bubbles are completely scraped off, collect the bubbles to obtain a boron-enriched product; after testing, the boron separation removal rate is 65.35%.

[0057] Step 4, washing the boron-enriched product in step 3 with 50 mL of water, performing a boron analysis process with 50 mL of 0.01 mol / L sulfuric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0058] The boron concentration in the pickled product is 3.43 g / L.

[0059] Step 5, washing the analyzed flotation agent obtained in step 4 with 50 mL of water, 10 mL of 1 mol / L sodium hydroxide solution, and 50 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as a flotation agent for boron separation.

[0060] Embodiment 2

[0061] A method for preparing a flotation agent for boron separation comprises the following steps:

[0062] Step 1, adding 5 g of meglumine and 2 g of K2CO3 into methanol, and dispersing them evenly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.13 mol / L;

[0063] Step 2, adding 6g of 1-chlorohexadecane to the first mixture for reaction at a reaction temperature of 50°C for 48 hours; after the reaction, performing rotary evaporation on the reaction product, washing the obtained solid matter with deionized water, and drying at 30°C for 48 hours to obtain the flotation agent for boron separation.

[0064] Step 3, complex flotation separation of boron: add 10g of the flotation agent for boron separation to 500mL of the diluted Dachaidan brine, stir for 8h, pour into the flotation tank, bubbling speed of 1700r / min, float until the bubbles are completely scraped off, collect the bubbles to obtain a boron-enriched product; the boron separation removal rate is 93.65%.

[0065] The contents of various elements in Dachaidan brine are shown in Table 1.

[0066] Table 1 Main element contents in Dachaidan brine

[0067]

[0068] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 50 mL of 0.02 mol / L hydrochloric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0069] The boron concentration in the pickled product is 4.83 g / L.

[0070] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.02 mol / L potassium hydroxide solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0071] Embodiment 3

[0072] A method for preparing a flotation agent for boron separation comprises the following steps:

[0073] Step 1, adding 10 g of meglumine and 4 g of Na2CO3 into methanol, and dispersing them evenly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.26 mol / L;

[0074] Step 2, adding 20g of 1-iodooctadecane to the first mixture for reaction at a reaction temperature of 50°C for 96 hours; after the reaction, performing rotary evaporation on the reaction product, washing the obtained solid matter with deionized water, and drying at 40°C for 24 hours to obtain the flotation agent for boron separation.

[0075] Step 3, complex flotation separation of boron: add 8g of the flotation agent for boron separation to 500mL of the diluted Dachaidan brine, stir for 8h, pour into the flotation tank, bubbling speed of 1500r / min, float until the bubbles are completely scraped off; the boron separation removal rate is 88.13%.

[0076] The contents of various elements in Dachaidan brine are shown in Table 1

[0077] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 50 mL of 0.02 mol / L sulfuric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0078] The boron concentration in the pickled product is 3.26 g / L.

[0079] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.02 mol / L ammonia solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0080] Embodiment 4

[0081] A method for preparing a flotation agent for boron separation comprises the following steps:

[0082] Step 1, adding 5 g of meglumine and 2.5 g of K2CO3 into methanol, and dispersing them evenly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.13 mol / L;

[0083] Step 2, adding 20g of 1-bromooctadecane to the first mixture for reaction at a reaction temperature of 50°C for 96 hours; after the reaction, performing rotary evaporation on the reaction product, washing the obtained solid matter with deionized water, and drying at 40°C for 24 hours to obtain the flotation agent for boron separation.

[0084] Step 3, complex flotation separation of boron: add 7g of the flotation agent for boron separation to 500mL of the diluted Dachaidan brine, stir for 8h, pour into the flotation tank, bubbling speed of 1500r / min, float until the bubbles are completely scraped off; the boron separation removal rate is 80.03%.

[0085] The contents of various elements in Dachaidan brine are shown in Table 1.

[0086] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 50 mL of 0.02 mol / L sulfuric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0087] The boron concentration in the pickled product is 3.06 g / L.

[0088] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.02 mol / L potassium hydroxide solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0089] Embodiment 5

[0090] A method for preparing a flotation agent for boron separation comprises the following steps:

[0091] Step 1, adding 15 g of meglumine and 2 g of K2CO3 into deionized water, and dispersing them evenly to obtain a first mixture;

[0092] Step 2, adding 20 mL of 1,2-epoxyoctadecane to the first mixture for reaction, the reaction temperature is 70° C., and the reaction time is 96 hours; after the reaction is completed, the reaction product is vacuum filtered, the obtained solid matter is washed with deionized water and dried at 50° C. for 48 hours to obtain the flotation agent for boron separation.

[0093] Step 3, complex flotation separation of boron: add 10g of the flotation agent for boron separation to 500mL of Dachaidan brine diluted 4 times, stir for 8h, pour into the flotation tank, bubbling speed is 1700r / min, float until the bubbles are completely scraped off; the boron separation removal rate is 92.65%.

[0094] The contents of various elements in Dachaidan brine are shown in Table 1.

[0095] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 50 mL of 0.05 mol / L hydrochloric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0096] The boron concentration in the pickled product is 5.11 g / L.

[0097] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 25 mL of 0.05 mol / L sodium hydroxide solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0098] Embodiment 6

[0099] A method for preparing a flotation agent for boron separation comprises the following steps:

[0100] Step 1, adding 20 g of meglumine and 5 g of K2CO3 into ethanol and dispersing them evenly to obtain a first mixture;

[0101] Step 2, adding 35g of 1,2-epoxydodecane to the first mixture for reaction, the reaction temperature is 60°C, and the reaction time is 24 hours; after the reaction is completed, the reaction product is vacuum filtered, the obtained solid matter is washed with a mixed solution of water and ethyl acetate, and dried at 60°C for 12 hours to obtain the flotation agent for boron separation.

[0102] Step 3, complex flotation separation of boron: add 5g of the flotation agent for boron separation to 500mL of a solution containing 0.01mol / L boron, stir for 24h, pour into a flotation tank, bubbling at a speed of 1900r / min, and float until the bubbles are completely scraped off; the boron separation removal rate is 82.37%.

[0103] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 25 mL of 1 mol / L phosphoric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0104] The boron concentration in the pickled product is 4.03 g / L.

[0105] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.05 mol / L sodium hydroxide solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0106] Embodiment 7

[0107] A method for preparing a flotation agent for boron separation comprises the following steps:

[0108] Step 1, adding 10 g of meglumine and 4 g of Na2CO3 into methanol, and dispersing them evenly to obtain a first mixture;

[0109] Step 2, adding 20g of 1-epoxytetradecane to the first mixture for reaction at a reaction temperature of 50°C for 96 hours; after the reaction, the reaction product is subjected to rotary evaporation, the obtained solid matter is washed with deionized water, and dried at 40°C for 24 hours to obtain the flotation agent for boron separation.

[0110] Step 3, boron complex flotation separation: 8g of the flotation agent for boron separation was added to 500mL of the Dachaidan solution diluted 4, stirred for 15h, poured into a flotation tank, and the bubbling speed was 1500r / min, and flotation was performed until the bubbles were completely scraped off; the boron separation removal rate was 88.13%. The contents of each element in the Dachaidan brine are shown in Table 1.

[0111] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 50 mL of 0.02 mol / L sulfuric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0112] The boron concentration in the pickled product is 3.26 g / L.

[0113] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.02 mol / L ammonia solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0114] Embodiment 8

[0115] A method for preparing a flotation agent for boron separation comprises the following steps:

[0116] Step 1, adding 18 g of meglumine and 4 g of K2CO3 into ethanol and dispersing them evenly to obtain a first mixture;

[0117] Step 2, adding 30g of 1-epoxydodecane to the first mixture for reaction, the reaction temperature is 60°C, and the reaction time is 24 hours; after the reaction is completed, the reaction product is filtered, the obtained solid matter is washed with a hydrated ethyl acetate mixed solution and dried at 60°C for 12 hours to obtain the flotation agent for boron separation.

[0118] Step 3, complex flotation separation of boron: add 6g of the flotation agent for boron separation to 500mL of a solution containing 0.012mol / L boron, stir for 24h, pour into a flotation tank, bubbling at a speed of 1800r / min, and float until the bubbles are completely scraped off; the boron separation removal rate is 80.32%.

[0119] Step 4, washing the boron-enriched product in step 3 with 100 mL of water, performing a boron analysis process with 30 mL of 0.02 mol / L phosphoric acid washing solution, and obtaining a flotation agent and an acid-washed product after analysis by vacuum filtration;

[0120] The boron concentration in the pickled product is 3.53 g / L.

[0121] Step 5, washing the analyzed flotation agent obtained in step 4 with 100 mL of water, 50 mL of 0.05 mol / L sodium hydroxide solution, and 100 mL of water in sequence to obtain a regenerated flotation agent, and the regenerated flotation agent is returned to step 2 for use as the flotation agent for boron separation.

[0122] Preparation process of boron complex flotation agent: meglumine undergoes condensation reaction with long-chain alkyl compounds. Taking long-chain alkane bromide as an example, long-chain alkane bromide reacts with the methylamino group of meglumine to remove small molecule HBr, thereby connecting a long carbon chain to the methylamino group in meglumine.

[0123] One end of the flotation agent has a hydrophobic group with a suitable number of carbon chains, and the other end has a polyhydroxy hydrophilic group (methylglucamine functional group) that can complex boron. When flotation is performed, only such a compound should be added to have the ability to complex and float boron in the aqueous solution. The polyhydroxy compound N-methyl-D-glucamine (NMDG) has a polyhydroxy structure and is an excellent complexing agent for boron; the long carbon chain in the long-chain alkyl is hydrophobic. During flotation, its long-chain alkyl is attached to the surface of the bubble by hydrophobic action, so that the complex ion is floated.

[0124] Alkyl compounds have good activity due to the bromine or epoxy groups in their structures. Under certain conditions, they can react with the amine groups in NMDG, remove small molecules, and condense to form the target product. The reaction formula is as follows: Figure 8 As shown. Long-chain alkanes are hydrophobic. Since the two cis-hydroxyl groups of NMDG can undergo a strong complexation reaction with boron in the solution, the synthesized product has both hydrophilic and hydrophobic groups and can be used as a complexing agent and a frother for flotation separation of boron in the solution. The flotation mechanism is as follows: Fig. 9 shown.

[0125] Boron desorption process: When the solution pH is less than 2, the complexation formed by boric acid and polyols is reduced, which will open the hydrogen bond covalent bonds of the complex and cause boron desorption. Therefore, acid washing must be added for desorption and the solution pH must be less than 2.

[0126] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0127] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A boron flotation separation method, characterized in that: include: Adding a flotation agent for boron separation to the boron-containing solution, performing aeration and stirring flotation after reaction and complexation, and collecting the foam to obtain a boron-enriched product; the amount of the flotation agent for boron separation added is 0.5 to 10 times the mass of the boron in the boron-containing solution; The general structural formula of the flotation agent used for boron separation is as follows: in, R is C 10～18 Long chain alkyl groups; Or, R is a hydroxy-substituted C 10～18 Long chain alkyl groups; The step also includes step 2, washing the boron-enriched product, adding an acid wash solution to carry out a boron analysis process, and obtaining a post-analysis flotation agent and an acid wash product; the pH of the boron analysis process is less than 2; The method further comprises step 3, wherein the resolved flotation agent obtained in step 2 is subjected to water washing and alkali solution washing processes to obtain a regenerated flotation agent, and the regenerated flotation agent is returned for complex flotation separation of boron; the alkali solution is sodium hydroxide solution, potassium hydroxide solution, and ammonia water, and the alkali concentration in the alkali solution is 0.01-1 mol / L.

2. The boron flotation separation method according to claim 1, characterized in that: The pickling solution is a hydrochloric acid solution, a sulfuric acid solution, a nitric acid solution, or a phosphoric acid solution, and the acid concentration in the pickling solution is 0.01 to 1 mol / L; The boron concentration in the pickled product is ≤5.9 g / L.

3. The boron flotation separation method according to claim 1, characterized in that: The flotation agent for boron separation is prepared by the following steps: Step 1', adding meglumine and an alkaline catalyst into an organic solvent, and dispersing them uniformly to obtain a first mixture, wherein the concentration of meglumine in the first mixture is 0.05 to 0.42 mol / L; The mass ratio of meglumine to the alkaline catalyst in the first mixture is 1:0.1-0.5; Step 2', adding a long-chain alkyl compound to the first mixture for reaction, wherein the molar ratio of the meglumine to the long-chain alkyl compound is 1:0.8-2, the reaction temperature is 50-90°C, and the reaction time is more than 12 hours; after the reaction is completed, the reaction product is subjected to solid-liquid separation, and the solid matter is washed and dried to obtain the flotation agent for boron separation; The long-chain alkyl compound is C 10 ~C 18 Alkylene oxide and / or C 10 ~C 18 of alkyl halides.

4. The boron flotation separation method according to claim 3, characterized in that: The alkaline catalyst is carbonate, KI, KOH, KHCO3, K2O, MgO; the carbonate is sodium carbonate or potassium carbonate, and the organic solvent is methanol, ethanol, chloroform, dichloromethane or acetone.

5. The boron flotation separation method according to claim 3, characterized in that: The mass ratio of meglumine to the alkaline catalyst in the first mixture is 1:0.4-0.

5.

6. The boron flotation separation method according to claim 3, characterized in that: In the step 2', stirring is performed during the reaction, the reaction temperature is 40-50° C., and the reaction time is more than 48 hours.

7. The boron flotation separation method according to claim 3, characterized in that: In the step 2', the solid matter is washed by using petroleum ether, dichloromethane, chloroform, water or ethyl acetate solution.

8. The boron flotation separation method according to claim 3, characterized in that: The long-chain alkyl compound is C 10 ~C 18 Chloroalkanes, C 10 ~C 18 of bromoalkyl, C 10 ~C 18 of iodoalkyl.

Images