Rubidium extractant and its preparation method and application

Abstract

The present invention belongs to the technical field of metal refining, and specifically relates to a rubidium extractant and a preparation method and application thereof. An amine compound and a carboxylic acid compound are dissolved in a solvent and subjected to an amidation reaction to obtain a rubidium extractant; wherein the amine compound is o-amino-p-tert-butylphenol, and the carboxylic acid compound is p-hydroxybenzenecarboxylic acid. The present invention can improve the extraction rate and selectivity of rubidium.

Description

Technical Field

[0001] The invention belongs to the technical field of metal refining, and in particular relates to a rubidium extractant and a preparation method and application thereof. Background Art

[0002] Rubidium is a soft, active, rare metal with unique photoelectric properties. It is widely used in traditional fields such as atomic clocks, photovoltaic cells, special glass, biochemistry, and medicine. However, rubidium does not have independently produced minerals. It mainly exists in feldspar and mica in the form of isomorphism to replace potassium. It has long been a by-product of lithium and cesium extraction. Although rubidium is contained in brine and accounts for more than 90% of the total reserves, rubidium is usually present in trace concentrations (0-20 mg / L), which makes extraction cost high and difficult. Therefore, current research on rubidium extraction technology mainly focuses on extracting rubidium from ores.

[0003] The extraction method has been a hot topic in recent years. Its advantages are fast reaction speed, simple operation, high extraction efficiency, and it is also widely used in the industrial extraction of rubidium and cesium. The extraction mechanism of the extraction method is that the target ion can react and complex with certain groups on the extractant, or undergo ion exchange with the organic reagent, so that the target ion enters the organic phase that is immiscible with water, and the rubidium and cesium ions are extracted from the solution. At present, the organic reagents that can efficiently extract rubidium and cesium from the solution are mainly phenol alcohol reagents and crown ethers. Although calixarene crown ethers show good selectivity for rubidium (Mohite, BS, Burungale, SH, 1999. Separation of rubidium from associated elements by solventextraction with dibenzo-24-crown-8. Anal. Lett. 32, 173-183.; Ertan, B., , Y., 2016. Separation of rubidium from boron containing clay wastesing solvent extraction. Powder Technol. 295, 254-260.), but due to its high price and toxicity, substituted phenols are more worthy of application as extractants.

[0004] The most widely used phenol-alcohol reagent is 4-tert-butyl-2-(α-methylbenzyl)phenol (t-BAMBP), while cyclohexane, xylene and sulfonated kerosene are the most common solvents for the above-mentioned extractants. t-BAMBP belongs to the phenol-substituted extractant, is weakly acidic, and is basically insoluble in water. It has the advantages of being non-volatile, stable and non-toxic, highly selective, fast in reaction, high in extraction rate, simple in stripping and good in recycling.

[0005] The degree of alkali metal extraction by t-BAMBP follows the order of Cs > Rb > K > Na > Li. Li and Liu studied the extraction of rubidium and cesium from brine using t-BAMBP (Li, R., Liu, C., 2014. Research of extraction andinfluencing factor of Rb and Cs with t-BAMBP. Journal of Salt and ChemicalIndustry 43 (1), 17-19.). The experimental results showed that sodium had no effect on the extraction of rubidium, while potassium had a negative effect on the extraction of rubidium. The extraction rate of rubidium decreased significantly with the increase of potassium concentration in the solution. In another study, Rb and Cs were extracted from salt lake brine after potassium extraction (Liu, S., Liu, H., Huang, Y., Yang, W., 2015. Solvent extraction of rubidium and cesium from salt lake brine with t-BAMBP-kerosenesolution. Trans. Nonferrous Metals Soc. China 25, 329-334.). Magnesium was precipitated before solvent extraction, and most of K and Na were removed by washing the loaded organic phase several times. Finally, Rb and Cs were effectively enriched and separated from other metal ions. Wang et al. studied the extraction of rubidium from lithium-containing brine using t-BAMBP as an extractant and cyclohexane as a diluent (Wang, J., Che, D., Qin, W., 2015. Extraction of rubidium by t-BAMBP in cyclohexane. Chinese J. Chem. Eng. 23, 1110-1113.). The results showed that a better extraction effect could be obtained when the pH was 13 and the t-BAMBP concentration was 1 mol / L. In a high alkalinity solution, t-BAMBP can effectively extract Cs + and Rb +However, the traditional extraction method consumes a lot of alkali and acid, and the discharge of alkaline raffinate still needs to be considered.

[0006] Based on the above analysis, the development of a rubidium extractant with low alkali, high extraction efficiency, good selectivity and low cost will greatly promote the economic and environmentally friendly extraction of rubidium. Summary of the invention

[0007] The purpose of the present invention is to provide a rubidium extractant, which can improve the extraction rate and selectivity of rubidium. The present invention also provides a preparation method and application of the rubidium extractant.

[0008] The rubidium extractant of the present invention has a structural formula of one of the following structural formulas:

[0009]

[0010] Formula 1

[0011] in:

[0012] R is C0-C 17 A hydrocarbon group or an alkoxy ether group having the structural formula 2,

[0013]

[0014] Formula 2

[0015] In formula 2, R 1 C1-C 17 The hydrocarbon group, R 2 C1-C 17 A hydrocarbon group, wherein n is 1, 2 or 3.

[0016] The rubidium extractant of the invention is prepared by a one-pot method.

[0017] The preparation method of the rubidium extractant of the present invention comprises dissolving an amine compound and a carboxylic acid compound in a solvent and performing an amidation reaction to obtain the rubidium extractant; wherein the amine compound is o-amino-p-tert-butylphenol, and the carboxylic acid compound is p-hydroxybenzenecarboxylic acid.

[0018] The molar ratio of the amine compound to the carboxylic acid compound is 1:1-1.5.

[0019] The solvent is N,N-dimethylformamide (DMF) or xylene, and the molar ratio of the amine compound to the solvent is 1:5-10.

[0020] The amidation reaction temperature is 90-150° C., and the amidation reaction time is 10-18 hours.

[0021] The application of the rubidium extractant of the present invention comprises the following steps:

[0022] (1) Calcination

[0023] The lithium ore and the chloride salt are ground, roasted, and cooled to obtain a mixture;

[0024] (2) Dissolution

[0025] Grinding the mixture obtained in step (1) to obtain a mixture powder, adding deionized water and NaOH to the mixture powder for stirring and dissolution, and filtering to obtain a filtrate;

[0026] (3) Extraction

[0027] The rubidium extractant is dissolved in the extraction solvent to obtain a mixed extractant, and the mixed extractant is added to the filtrate obtained in step (2) for stirring and extraction, and the liquids are separated to obtain an extract containing rubidium.

[0028] In step (1), the lithium ore is lepidolite ore or spodumene ore; the chloride salt is a mixture of sodium chloride and calcium chloride, and the mass ratio of the lithium ore, sodium chloride and calcium chloride is 2-2.5:1-1.2:1-1.2.

[0029] In step (1), the calcination temperature is 800-1000° C. and the calcination time is 40-60 minutes.

[0030] In step (2), the mass ratio of the mixture powder, deionized water and NaOH is 1:3-4:0.08-0.15; the stirring temperature is 65-80° C., the stirring speed is 150-400 r / min, and the stirring time is 1-3 hours.

[0031] In step (3), the extraction solvent is one of benzene, xylene, octanone or sulfonated kerosene, the molar ratio of the rubidium extractant to the extraction solvent is 1:5-10.2, the volume ratio of the filtrate to the mixed extractant is 1:3-5, the extraction temperature is 10-35°C, and the extraction time is 15-30 minutes.

[0032] R is preferably: (1) a saturated alkyl group, such as a straight-chain alkyl group or a branched alkyl group; (2) an olefin group or an olefin alkyl group containing a single or multiple double bonds; (3) a saturated or unsaturated cycloalkyl group, wherein the cycloalkyl group is preferably a five-membered ring or a six-membered ring; (4) an alkylaryl group or an arylalkyl group containing an aromatic structure, such as an alkyl-substituted phenyl group, an alkyl-substituted condensed ring aromatic group, a phenyl group or a condensed ring aromatic alkyl group

[0033] R is more preferably C1-C 17 A straight-chain or branched alkane group, C2-C 17 Olefin or C6-C 12 Aromatic hydrocarbon group.

[0034] R is more preferably -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2(CH3)CHCH2-, -CH=CH-, -CH=CH-CH2-, , , or C 10 -C 17 of a monoolefin group.

[0035] The beneficial effects of the present invention are as follows:

[0036] (1) The present invention adopts a chloride salt roasting method to treat lithium ore, thereby increasing the dissolution rate of rubidium in the lithium ore.

[0037] (2) The amide group in the rubidium extractant of the present invention is a good coordination group of rubidium, which can form a chemical bond with rubidium to improve the efficiency and selectivity of extraction. In addition, the bisphenol hydroxyl structure can react with rubidium metal in a dual-action functional group structure to enhance the extraction efficiency of rubidium. From the extraction principle, the hydroxyl groups in the bisphenol hydroxyl structure extractant molecule are linked by structures such as alkyl, alkoxy, and aryl groups, and the length of the carbon chain, the position and number of the branched structure or the oxygen atom are easy to control, which is conducive to improving and regulating the properties of the extractant. At the same time, after the dual functional groups react with rubidium metal, the electronic cloud structure between the functional groups changes, which can make the chemical bond formed between the extractant and rubidium more stable, and improve the binding ability of the bisphenol hydroxyl functional group structure with rubidium. The amide group is introduced into the molecular structure of the rubidium extractant. Since the amide group can form a coordination bond with rubidium, the selectivity of the extractant for rubidium is improved while the extraction efficiency is increased.

[0038] In view of the improvement of the extraction effect of the bisphenol hydroxyl structure and the excellent metal chelating properties of the amide structure for rubidium, the present invention innovatively combines bisphenol hydroxyl and amide to form a bisphenol hydroxyl rubidium extractant to enhance its extraction efficiency for valuable metals such as rubidium.

[0039] (3) The present invention uses a bisphenol hydroxyl rubidium extractant containing an amide structure for the extraction of rubidium after the lithium ore is roasted and dissolved, which can efficiently and selectively recover the rubidium in the lithium ore. Compared with the rubidium extractant commonly used in the prior art, the extraction rate and selectivity of rubidium can be improved.

[0040] (4) The extraction process of the present invention is carried out in a low-alkaline environment, which reduces the use of caustic soda, effectively controls the cost of the extraction process, and reduces the pollution to the environment caused by alkaline water discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The 4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol prepared in Example 1 1 H-NMR spectrum.

[0042] Figure 2 The 4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol prepared in Example 1 13 C-NMR spectrum.

[0043] Figure 3 This is the infrared spectrum of 4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol prepared in Example 1.

[0044] Figure 4 It is a comparison chart of the extraction rate results of Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0045] The present invention is further described below with reference to the embodiments.

[0046] Example 1

[0047] 16.52g of o-amino-p-tert-butylphenol and 18.22g of p-hydroxyphenylacetic acid were dissolved in 60g of DMF, put into a flask together, and reacted in a water bath. The reaction temperature was controlled at 90°C and the stirring speed was controlled at 200r / min. The reaction was carried out for 10h. After the reaction was completed, vacuum rotary evaporation was performed, and the mixture was washed with water and filtered to obtain t-BHAP (4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol, formula 3). 1 H-NMR diagram Figure 1 , 4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol 13 C-NMR diagram Figure 2 , the infrared results of 4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol are shown in Figure 3 And Table 1.

[0048]

[0049] Formula 3

[0050]

[0051] The application of rubidium extractant comprises the following steps:

[0052] (1) Calcination

[0053] 10 g of spodumene ore, 5 g of sodium chloride and 5 g of calcium chloride were fully ground in an agate mortar, and then heated to 800° C. at a rate of 10° C. per minute in a muffle furnace, calcined at this temperature for 40 minutes, and cooled to obtain a mixture;

[0054] (2) Dissolution

[0055] The mixture obtained in step (1) was ground to obtain a mixture powder, the mixture powder was placed in a flask, 70 g of deionized water was added thereto, and 1.6 g of NaOH was added thereto, and then rubidium was dissolved in a water bath at a dissolution temperature of 65° C. The mixture was stirred with a stirrer at a speed of 150 r / min for 1 hour, and filtered after stirring to obtain a filtrate;

[0056] (3) Extraction

[0057] t-BHAP and 60 ml of xylene were placed in a beaker and stirred for 1 h by a rotor to fully dissolve them, and a 1.6 mol / L mixed extractant was prepared. The mixed extractant was added to the filtrate obtained in step (2) for stirring and extraction. The volume ratio of the filtrate to the mixed extractant was 1:3. The mixture was stirred for 15 min by a stirrer at a speed of 600 r / min and an extraction temperature of 35°C. The liquids were separated to obtain an extract containing rubidium and a raffinate.

[0058] The rubidium and lithium contents in the filtrate and raffinate were detected by atomic absorption spectrometry, and the extraction rate was calculated. The results are shown in Table 2 and Figure 4 .

[0059]

[0060] Example 2

[0061] 16.52 g of o-amino-p-tert-butylphenol and 22.82 g of p-hydroxyphenylacetic acid were dissolved in 73 g of DMF, put into a flask together, and reacted in a water bath. The reaction temperature was controlled at 150°C, the stirring speed was controlled at 200 r / min, and the reaction was carried out for 18 hours. After the reaction was completed, the mixture was concentrated by vacuum rotary evaporation, washed with water, and filtered to obtain t-BHAP (4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol).

[0062] The application of rubidium extractant comprises the following steps:

[0063] (1) Calcination

[0064] 12.5 g of spodumene ore, 6 g of sodium chloride and 6 g of calcium chloride were fully ground in an agate mortar, then heated to 1000° C. at a rate of 10° C. per minute in a muffle furnace, calcined at this temperature for 60 minutes, and cooled to obtain a mixture;

[0065] (2) Dissolution

[0066] The mixture obtained in step (1) is ground to obtain a mixture powder, the mixture powder is placed in a flask, 98 g of deionized water is added thereto, and 3.68 g of NaOH is added thereto, and then rubidium is dissolved in a water bath at a dissolution temperature of 80° C., a stirrer is used for stirring, a stirring speed of 400 r / min, a stirring time of 3 hours, and filtering after stirring to obtain a filtrate;

[0067] (3) Extraction

[0068] t-BHAP and 60 ml of xylene were placed in a beaker and stirred for 1 h by a rotor to fully dissolve them, and a 0.8 mol / L mixed extractant was prepared. The mixed extractant was added to the filtrate obtained in step (2) for stirring extraction. The volume ratio of the filtrate to the mixed extractant was 1:5. The mixture was stirred for 30 min by a stirrer at a speed of 600 r / min and an extraction temperature of 10°C. The liquids were separated to obtain an extract containing rubidium and a raffinate.

[0069] The rubidium and lithium contents in the filtrate and raffinate were detected by atomic absorption spectrometry, and the extraction rate was calculated. The results are shown in Table 3 and Figure 4 .

[0070]

[0071] Example 3

[0072] 16.52 g of o-amino-p-tert-butylphenol and 15.22 g of p-hydroxyphenylacetic acid were dissolved in 37 g of DMF, put into a flask together, and reacted in a water bath. The reaction temperature was controlled at 120°C, the stirring speed was controlled at 200 r / min, and the reaction was carried out for 15 hours. After the reaction was completed, the mixture was concentrated by vacuum rotary evaporation, washed with water, and filtered to obtain t-BHAP (4-tert-butyl-2-(p-hydroxyphenylacetamide)phenol).

[0073] The application of rubidium extractant comprises the following steps:

[0074] (1) Calcination

[0075] 12 g of spodumene ore, 5.5 g of sodium chloride and 5.5 g of calcium chloride were fully ground in an agate mortar, then heated to 900° C. at a rate of 10° C. per minute in a muffle furnace, calcined at this temperature for 50 minutes, and cooled to obtain a mixture;

[0076] (2) Dissolution

[0077] The mixture obtained in step (1) was ground to obtain a mixture powder, the mixture powder was placed in a flask, 70 g of deionized water was added thereto, and 3 g of NaOH was added thereto, and then rubidium was dissolved in a water bath at a dissolution temperature of 70° C., a stirrer was used for stirring, a stirring speed of 200 r / min, a stirring time of 1.5 hours, and after stirring, the mixture was filtered to obtain a filtrate;

[0078] (3) Extraction

[0079] t-BHAP and 60 ml of xylene were placed in a beaker and stirred for 1 h by a rotor to fully dissolve them, and a 1.2 mol / L mixed extractant was prepared. The mixed extractant was added to the filtrate obtained in step (2) for stirring and extraction. The volume ratio of the filtrate to the mixed extractant was 1:4. The mixture was stirred for 20 min by a stirrer at a speed of 600 r / min and an extraction temperature of 25°C. The liquids were separated to obtain an extract containing rubidium and a raffinate.

[0080] The rubidium and lithium contents in the filtrate and raffinate were detected by atomic absorption spectrometry, and the extraction rate was calculated. The results are shown in Table 4 and Figure 4 .

[0081]

[0082] Comparative Example 1

[0083] The t-BHAP used in the rubidium extractant was replaced by t-BAMBP, and the other steps were the same as those in Example 1.

[0084] The rubidium and lithium contents in the filtrate and raffinate were detected by atomic absorption spectrometry, and the extraction rate was calculated. The results are shown in Table 5 and Figure 4 .

[0085]

Claims

1. A rubidium extractant, characterized in that The structural formula is as follows: Formula 1 in: R is C0-C 17 A hydrocarbon group or an alkoxy ether group having the structural formula 2, Formula 2 In formula 2, R 1 C1-C 17 The hydrocarbon group, R 2 C1-C 17 A hydrocarbon group, wherein n is 1, 2 or 3.

2. A method for preparing the rubidium extractant according to claim 1, characterized in that An amine compound and a carboxylic acid compound are dissolved in a solvent to carry out an amidation reaction to obtain a rubidium extractant; wherein the amine compound is o-amino-p-tert-butylphenol, and the carboxylic acid compound is p-hydroxybenzenecarboxylic acid.

3. The method for preparing the rubidium extractant according to claim 2, characterized in that The molar ratio of the amine compound to the carboxylic acid compound is 1:1-1.

5.

4. The method for preparing the rubidium extractant according to claim 2, characterized in that The solvent is N,N-dimethylformamide or xylene, and the molar ratio of the amine compound to the solvent is 1:5-10.

5. The method for preparing the rubidium extractant according to claim 2, characterized in that The amidation reaction temperature is 90-150° C., and the amidation reaction time is 10-18 hours.

6. A use of the rubidium extractant according to claim 1, characterized in that The steps include: (1) Calcination The lithium ore and the chloride salt are ground, roasted, and cooled to obtain a mixture; (2) Dissolution Grinding the mixture obtained in step (1) to obtain a mixture powder, adding deionized water and NaOH to the mixture powder for stirring and dissolution, and filtering to obtain a filtrate; (3) Extraction The rubidium extractant is dissolved in the extraction solvent to obtain a mixed extractant, and the mixed extractant is added to the filtrate obtained in step (2) for stirring and extraction, and the liquids are separated to obtain an extract containing rubidium.

7. The use of the rubidium extractant according to claim 6, characterized in that In step (1), the lithium ore is lepidolite ore or spodumene ore; the chloride salt is a mixture of sodium chloride and calcium chloride, and the mass ratio of the lithium ore, sodium chloride and calcium chloride is 2-2.5:1-1.2:1-1.

2.

8. The use of the rubidium extractant according to claim 6, characterized in that In step (1), the calcination temperature is 800-1000° C. and the calcination time is 40-60 minutes.

9. The use of the rubidium extractant according to claim 6, characterized in that In step (2), the mass ratio of the mixture powder, deionized water and NaOH is 1:3-4:0.08-0.15; the stirring temperature is 65-80° C., the stirring speed is 150-400 r / min, and the stirring time is 1-3 hours.

10. The use of the rubidium extractant according to claim 6, characterized in that In step (3), the extraction solvent is one of benzene, xylene, octanone or sulfonated kerosene, the molar ratio of the rubidium extractant to the extraction solvent is 1:5-10.2, the volume ratio of the filtrate to the mixed extractant is 1:3-5, the extraction temperature is 10-35°C, and the extraction time is 15-30 minutes.

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