阅读说明：本技术 一种从盐湖卤水中萃取分离铷离子的方法 (Method for extracting and separating rubidium ions from salt lake brine ) 是由 石成龙 秦亚茹 李海朝 宋萍 杨小波 李宏霞 宋桂秀 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种从盐湖卤水中萃取分离铷离子的方法,包括以下步骤：称取适量萃取剂,将其溶解于稀释剂中,并搅拌混匀,形成有机相；将盐湖卤水浓缩成铷离子质量浓度高于10mg/L的卤水,得水相；将有机相和水相按照0.5-5:1的体积比混合,然后震荡5-60min,离心,分离并去除水相,得富集有铷离子的有机相。该方法可有效解决提高铷离子的萃取率,而且无需将萃取水相调整为强碱性,简化了萃取法提取铷的前处理过程,减轻了对设备的腐蚀,同时也避免了产生氢氧化镁沉淀,提高了铷离子的萃取效率。(The invention discloses a method for extracting and separating rubidium ions from salt lake brine, which comprises the following steps: weighing a proper amount of an extracting agent, dissolving the extracting agent in a diluent, and uniformly stirring to form an organic phase; concentrating salt lake brine into brine with the mass concentration of rubidium ions higher than 10mg/L to obtain a water phase; mixing the organic phase and the water phase according to the volume ratio of 0.5-5:1, then shaking for 5-60min, centrifuging, separating and removing the water phase to obtain the organic phase enriched with rubidium ions. The method can effectively improve the extraction rate of rubidium ions, does not need to adjust the extraction water phase to be strong alkaline, simplifies the pretreatment process of extracting rubidium by an extraction method, reduces the corrosion to equipment, avoids the generation of magnesium hydroxide precipitate, and improves the extraction efficiency of rubidium ions.)

1. A method for extracting and separating rubidium ions from salt lake brine is characterized by comprising the following steps:

(1) weighing an organic extractant, dissolving the organic extractant in a diluent, and uniformly stirring to form an organic phase;

(2) Concentrating salt lake brine into brine with the mass concentration of rubidium ions higher than 10mg/L to obtain a water phase;

(3) mixing the organic phase in the step (1) and the water phase in the step (2) according to the volume ratio of 0.5-5:1, then shaking for 5-60min, centrifuging, separating and removing the water phase to obtain an organic phase enriched with rubidium ions.

2. The method for extracting and separating rubidium ions from salt lake brine as claimed in claim 1, wherein the molar concentration of the extracting agent in the organic phase in the step (1) is 0.05-2.5 mol/L.

3. The method for extracting and separating rubidium ions from salt lake brine as claimed in claim 1, wherein the extractant is at least one of 18-crown-6 and derivatives thereof and 21-crown-7 and derivatives thereof.

4. The method for extracting and separating rubidium ions from salt lake brine as claimed in claim 1, wherein the structural formula of the extracting agent is as follows:

Wherein, R, R₁、R₂、R₃Is a hydrogen atom or a carbon atom having 1 to 20 alkyl, alkoxy or phenyl.

5. The method for extraction separation of rubidium ions from salt lake brine as claimed in claim 1, wherein the diluent is hydrophobic ionic liquid.

6. The method for extracting and separating rubidium ions from salt lake brine as claimed in claim 5, wherein the hydrophobic ionic liquid is an ionic compound consisting of anions and imidazole cations, and the anions are PF₆ ^-、(SO₂CF3)₂N^-、(SO₂CF₂CF₃)^2-and BF₄ ^-At least one of (1).

7. The method for extracting and separating rubidium ions from salt lake brine as claimed in claim 6, wherein the imidazole like cations have the following structural formula:

Wherein R is₁And R₂Is alkyl, alkenyl or alkynyl with the carbon number between 1 and 20.

Technical Field

The invention relates to the technical field of rubidium ion separation, in particular to a method for extracting and separating rubidium ions from salt lake brine.

Background

Rubidium is an extremely important rare precious metal resource and plays an important role in national defense, medicine, economy and energy. With the gradual reduction of solid mineral reserves and the increase of production costs, the extraction of rubidium has gradually shifted from solid mineral dominated to liquid mineral dominated. Salt lake brine containing rubidium ions in Qinghai and Tibet is a high-quality mineral source for extracting rubidium. The method for separating and extracting rubidium is developed for many years and mainly comprises a fractional crystallization method, a precipitation method, a solvent extraction method and an ion exchange method. The solvent extraction method has the characteristics of large treatment capacity, simple and convenient operation, simple flow and easy industrialization, and is an effective method for extracting rubidium from liquid rubidium ore.

At present, the most used extracting agent in the extraction method is substituted phenols, and the substituted phenols are more researched by t-BAMBP. the t-BAMBP has the advantages of easy synthesis, stable source, relatively mature technology, mass production and the like, and has wide industrial application prospect. the coordination selectivity of t-BAMBP to rubidium under alkaline conditions is far higher than that under neutral or acidic conditions, so that the alkalinity of an extraction system is important, but the alkalinity is too high, so that the production equipment is corroded. Adjusting the alkalinity of the brine necessarily produces a large amount of magnesium hydroxide precipitate, so a magnesium removal process is required before extraction. The magnesium removal method proposed by Liu He Hui of Hunan university at present is to add sodium hydroxide to remove magnesium, so that the method has many limitations, and because the generated magnesium hydroxide precipitate has adsorbability, a large amount of rubidium can be taken away in the precipitation process, so that the recovery rate is reduced; and the magnesium hydroxide has the problem of difficult filtration, is difficult to be applied in actual production, and limits the application of the extraction method in industry.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for extracting and separating rubidium ions from salt lake brine, which can effectively solve the problem that production equipment is seriously corroded due to the fact that an extraction water phase needs to be adjusted into strong alkalinity in order to improve extraction efficiency in the existing extraction method; meanwhile, magnesium hydroxide precipitate can be generated in the extraction process under a strong alkaline environment, and a part of rubidium ions can be taken away by the magnesium hydroxide precipitate, so that the extraction efficiency of the rubidium ions is low.

in order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:

A method for extracting and separating rubidium ions from salt lake brine comprises the following steps:

(1) Weighing an organic extractant, dissolving the organic extractant in a diluent, and uniformly stirring to form an organic phase;

(2) Concentrating salt lake brine into brine with the mass concentration of rubidium ions higher than 10mg/L to obtain a water phase;

(3) Mixing the organic phase in the step (1) and the water phase in the step (2) according to the volume ratio of 0.5-5:1, then shaking for 5-60min, centrifuging, separating and removing the water phase to obtain an organic phase enriched with rubidium ions.

Further, the molar concentration of the extracting agent in the organic phase in the step (1) is 0.05-2.5 mol/L.

further, the extractant is at least one of 18-crown-6 and derivatives thereof and 21-crown-7 and derivatives thereof.

further, the structural formula of the extracting agent is as follows:

wherein, R, R₁、R₂、R₃is alkyl, alkoxy or phenyl with hydrogen atom or carbon atom number of 1-20.

Further, the diluent is a hydrophobic ionic liquid.

Further, the hydrophobic ionic liquid is an ionic compound consisting of anions and imidazole cations, wherein the anions are PF₆ ^-、(SO₂CF3)₂N^-、(SO₂CF₂CF₃)^2-And BF₄ ^-At least one of; wherein, the specific structural formula of the anion is as follows:

Further, the imidazole cations have the following structural formula:

Wherein R is₁And R₂is alkyl, alkenyl or alkynyl with the carbon number between 1 and 20.

the beneficial effect that above-mentioned scheme produced does:

The organic phase prepared by mixing the organic extractant and the diluent can be directly used for extracting rubidium ions in salt lake brine without adjusting the pH value of the organic phase, so that the formation of magnesium hydroxide precipitate can be avoided, the extraction efficiency of the rubidium ions is improved, and the corrosion degree of production equipment can be reduced; moreover, the diluent in the invention is ionic liquid, is non-volatile, and cannot cause pollution to the environment.

The crown ether as extractant is one compound with large ring structure and specific cavity structure and pore size, and the cavity contains oxygen atom with lone electron pair capable of coordinating with target metal ion to form complex, with the cavity pore size of the crown ether 18-crown-6 and its derivative being about that ofThe cavity aperture of crown ether 21-crown-7 and derivatives thereof is aboutThe diameter of the target rubidium ion is aboutThe aperture size of the crown ether is well matched with the diameter of target rubidium ions, and the maximum electrostatic acting force is generated when the crown ether and the target rubidium ions interact with each otherThe bond energy of the bonding is highest, and the complex is most stable; lithium in brine solutionSodium saltPotassium saltMagnesium alloyAnd other impurity ions with too large or too small diameters have poor matching effect with the pore size of the extracting agent, so that the extracting agent has good selectivity on target ions, and finally the single-stage extraction efficiency of rubidium ions is higher. The solvent ionic liquid adopted by the invention has stronger hydrophobicity and good compatibility with the extractant crown ether, because the ionic liquid can exist in an organic phase in the form of anions and cations, an ionic environment is formed in the organic phase, when the extractant crown ether and rubidium ions form large complex cations to enter the organic phase, the anions of the ionic liquid can be compounded with the complex cations, so that the complex cations can stably exist, and the extraction rate of the rubidium ions is greatly improved. Therefore, the ionic liquid is used as a solvent, so that a volatile organic solvent is replaced, the system is more environment-friendly, the pollution to the environment is reduced, the ionic liquid can play a role of an extraction accelerator in the system, and the extraction efficiency of the extraction system on rubidium ions is improved.

Detailed Description