WO2020063913A1 - Preparation method for scandium fluoride - Google Patents

Abstract

Provided is a preparation method for scandium fluoride, comprising: performing extraction using an organic extracting agent and a scandium-containing solution to obtain a scandium-containing organic phase; and subjecting the scandium-containing organic phase to a precipitation reaction with a fluorine-containing mixed solution to obtain scandium fluoride. Scandium element in a scandium-containing solution is extracted primarily by means of an extraction process to obtain a scandium-containing organic phase, and then the scandium-containing organic phase is subjected to a precipitation reaction or back-extraction with a fluorine-containing mixed solution so as to obtain a scandium fluoride product. The method has the advantages of low cost, short process, high yield of scandium fluoride, etc.

Description

Preparation method of europium fluoride Technical field

The invention relates to the field of material chemistry, and in particular, to a method for preparing rhenium fluoride.

Background technique

Samarium fluoride (ScF ₃ ) can be used as an optical material, and is also an important raw material for the preparation of samarium metal and its alloys by molten salt electrolysis and metal thermal reduction methods. For the preparation of aluminum-rhenium master alloys by molten salt electrolysis, anhydrous rhenium fluoride is required. Due to the small particle size and large specific surface area of the ultrafine powder, the performance of the material is significantly improved after the material is made into an ultrafine powder. For example, when rhenium fluoride fine particle material is used as a raw material, the temperature of molten salt electrolysis can be reduced, and the loss of molten salt can be reduced. The sub-micron material refers to fine particles having a particle diameter of 0.1 μm to 1.0 μm.

At present, the preparation of thorium fluoride is mainly based on thorium oxide, which is obtained by a dry method or a wet method. The main problem of dry preparation is that it is corrosive to equipment and pollutes the environment. Generally, in the wet preparation method, thorium oxide is first dissolved with hydrochloric acid, and then a fluorinating agent is added to precipitate hydrated fluoride from the aqueous solution. Then, the thorium hydrate is subjected to dehydration treatment in a dry hydrogen fluoride stream to prepare anhydrous thorium fluoride. This method also has the problems of environmental pollution, and it is difficult to avoid hydrolysis to generate osmium fluorofluoride ScOF, which further affects the high ytterbium yield obtained by molten salt electrolysis.

Summary of the Invention

The main purpose of the present invention is to provide a method for preparing erbium fluoride, so as to solve the problems that the existing method for preparing erbium fluoride has complicated technology and low yield of erbium fluoride.

In order to achieve the above object, the present invention provides a method for preparing rhenium fluoride. The preparation method comprises: extracting an organic extractant with a rhenium-containing solution to obtain a rhenium-containing organic phase; and a rhenium-containing organic phase and a fluorine-containing mixed liquid A precipitation reaction was performed to obtain europium fluoride.

Further, the preparation method includes: the organic extractant is an organic solvent solution containing an acidic organic phosphorus extractant, the thallium-containing solution is a thallium-containing inorganic acid solution, and the thallium-containing inorganic acid solution is performed by using the organic solvent solution containing the acidic organic phosphorus extractant. Tritium extraction to obtain thorium-containing, organic phase; S2, wash the thorium-containing organic phase to remove impurities; S3, the fluorinated mixed solution is HF and / or NaF solution, add thorium-containing organic phase to the thorium-containing organic phase after the impurities are removed Fluoride mixed solution is subjected to back extraction. After the liquid-liquid separation, a complex anion solution and an unloaded organic phase are obtained. Hydrochloric acid is added to the complex anion solution to adjust the pH of the solution to form a ScF ₃ precipitate. After solid-liquid separation, a ScF ₃ precipitate and Precipitation mother liquor; S4, ScF _{3 is} precipitated, washed and dried to obtain europium fluoride.

Further, the preparation method comprises: performing a saponification reaction between an alkaline solution and an organic carboxylic acid extractant to obtain a saponification extractant, and the saponification extractant is the above-mentioned organic extractant; and extracting a part of the saponification extractant and the rhenium-containing solution to obtain钪 Organic phase; mixing the remaining saponified extractant with a fluorine-containing compound to obtain a fluorinated mixed liquid; precipitating reaction between the rhenium-containing organic phase and the fluorinated mixed liquid to obtain rhenium fluoride.

Further, the alkaline solution is an aqueous solution of a base, and the fluorine-containing compound is one or more of NaF, KF, and hydrofluoric acid.

Further, the alkaline solution is ammonia water, and the fluorine-containing compound is ammonium fluoride.

Further, before the saponification reaction is performed, the preparation method further comprises: mixing an alkaline solution, an organic carboxylic acid extractant and a phase regulator to obtain a reactant; and performing a saponification reaction to obtain a saponification extractant.

Further, the reactant is prepared by the following method: mixing an organic carboxylic acid extractant, a phase regulator, and an organic solvent to obtain an extractant organic solution; mixing the extractant organic solution and an alkaline solution to obtain the reactant; Preferably, the organic solvent is an alkane, more preferably one or more of n-octane, n-heptane, n-hexane, cyclohexane, and kerosene.

Further, the organic carboxylic acid extractant is an organic substance containing a carboxyl group, preferably one or more of a chain alkane carboxylic acid, an aromatic carboxylic acid, and a cyclic alkane carboxylic acid; preferably, the alkane carboxylic acid is selected From one or more of n-hexanoic acid, n-decanoic acid, dodecylcarboxylic acid, and isooctanoic acid; preferably, the aromatic hydrocarbon-based carboxylic acid is selected from the group consisting of secondary octylphenoxyacetic acid and / or secondary nonylphenoxy Acetic acid; preferably, the cyclic alkane carboxylic acid is selected from carboxylic acids containing cyclopentyl or cyclohexyl.

Further, the concentration of the phase regulator in the organic solution of the extractant is 5 to 25 vol%; preferably, the phase regulator is an alkyl alcohol, preferably one of n-butanol, n-hexanol, n-octanol and isooctanol Or more.

Further, in the organic solution of the extractant, the concentration of the organic carboxylic acid extractant is 0.5 to 3.5 mol / L.

Further, the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution is denoted as A, and 3 ≦ A ≦ 20.

Further, during the precipitation reaction, the ratio of the amount of fluoride ion to the amount of rhenium in the rhenium-containing organic phase is denoted as B, and 4≤B≤6, and the volume ratio of the rhenium-containing organic phase to the fluorine-containing mixed liquid is 1: 10 ～ 10: 1.

Further, the extraction process is performed under the conditions of pH 2-4.

Further, the precipitation reaction further includes: sequentially performing thermal aging, solid-liquid separation, washing, and drying treatments on the product system of the precipitation reaction to obtain submicron fluorene fluoride; preferably, the temperature of the thermal precipitation process is 90 to 150 ° C, time is 1-8h; preferably, the temperature of the drying process is 90-105 ° C; preferably, the washing process uses ethanol and / or water to wash the product system of the precipitation reaction.

Further, the precipitation reaction further includes: sequentially performing thermal aging, solid-liquid separation, washing, and drying on the product system of the precipitation reaction to obtain ammonium fluoride rhenium double salt precipitation; sequentially washing and dehydrating ammonium fluoride rhenium double salt precipitation Deammonia treatment to obtain micron-grade thorium fluoride; preferably, the temperature during the heat preservation and precipitation process is 80 to 120 ° C, and the time is 1 to 4h; preferably, the temperature during the drying process is 90 to 105 ° C; preferably, dehydration The temperature of the deamination process is 300 to 400 ° C. and the time is 2 to 4 hours. Preferably, the washing process uses ethanol and / or water to wash the ammonium fluoride rhenium double salt precipitate.

Further, in S3, the ratio of the amount of F ^- ions in the HF and / or NaF solution to the rhenium ^- containing substance in the rhenium-containing inorganic acid solution is greater than 3 and less than 4.5.

Further, the acidic organic phosphorus extractant is one or more selected from the group consisting of bis (2-ethylhexyl) phosphoric acid, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and Cyanex272 extractant.

Further, the organic extractant in the organic solvent solution containing the acidic organic phosphorus extractant is at least one of alkanes or mixtures thereof, or aromatic hydrocarbons having a density less than water; preferably, the alkanes or mixtures thereof include N-heptane, n-hexane, and kerosene; preferably, aromatic hydrocarbons include benzene and toluene.

Further, the concentration of the acidic organic phosphorus extractant in the organic solvent solution containing the acidic organic phosphorus extractant is 0.01 mol / L to 4 mol / L.

Further, the rhenium-containing inorganic acid solution is a rhenium-containing sulfuric acid solution, a hydrochloric acid solution, or a nitric acid solution.

Further, the volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the rhenium-containing inorganic acid solution is (1:20) to (1: 1).

Further, the volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the HF and / or NaF solution in S3 is (1:20) to (20: 1).

Further, S4 includes: washing the ScF ₃ precipitate with ethanol and water, respectively.

Furthermore, the temperature for washing with ethanol is 20 to 40 ° C, and the temperature for washing with water is 50 to 90 ° C.

Further, in S2, the washing liquid used for the washing treatment is a 0.1 to 2 mol / L hydrochloric acid aqueous solution or a 0.1 to 1 mol / L sulfuric acid aqueous solution.

Further, the precipitated mother liquor in S3 is added to HF and / or NaF and returned to the back extraction processing step for use, and the unloaded organic phase is returned to S1 for the radon extraction treatment step for use.

Further, the mixing in the krypton extraction and back extraction processes uses mechanical mixing or ultrasonic mixing to accelerate the reaction progress.

Further, the reaction temperature of the back extraction is 20 to 70 ° C, and preferably 25 to 45 ° C.

Further, in S1, the ratio of the amount of the acidic organic phosphorus extractant in the organic solvent solution containing the acidic organic phosphorus extractant to the amount of the thorium substance in the thorium-containing inorganic acid solution is greater than 3 and less than 20.

Further, the temperature at which SmF is precipitated and dried in S4 to form a HfF product is 90-105 ° C.

Applying the technical solution of the present invention, in the above preparation method, the thorium element in the thorium-containing solution is first extracted through an extraction process to obtain a thallium-containing organic phase, and then it is subjected to a precipitation reaction (or back extraction) with a fluorine-containing mixed solution. , To obtain thorium fluoride products. The above preparation method has the advantages of low cost, short process flow and high yield of thorium fluoride.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail with reference to the following embodiments.

As described in the background art, the existing preparation method of rhenium fluoride has the problems of complicated process and low yield of rhenium fluoride. In order to solve the above technical problems, the present application provides a method for preparing rhenium fluoride. The preparation method includes: extracting an organic extractant with a rhenium-containing solution to obtain a rhenium-containing organic phase; and mixing the rhenium-containing organic phase with fluorine. The solution was subjected to a precipitation reaction to obtain europium fluoride.

In the above preparation method, the thorium element in the thorium-containing solution is extracted through an extraction process to obtain a thallium-containing organic phase, and then it is subjected to a precipitation reaction (or back extraction) with a fluorine-containing mixed solution to obtain a thallium fluoride product. The above preparation method has the advantages of low cost, short process flow and high yield of thorium fluoride.

In a preferred embodiment, the preparation method includes: performing a saponification reaction between an alkaline solution and an organic carboxylic acid extractant to obtain a saponified extractant, where the saponified extractant is an organic extractant; a part of the saponified extractant and the rhenium-containing solution Extraction is performed to obtain a rhenium-containing organic phase; the remaining saponified extractant is mixed with a fluorinated compound to obtain a fluorinated mixed liquid; the rhenium-containing organic phase and the fluorinated mixed liquid are subjected to a precipitation reaction to obtain fluorinated fluorene.

The organic carboxylic acid extractant has surface activity due to its special hydrophilic and lipophilic structure. The unreacted organic carboxylic acid extractant in the organic phase reacts with the alkaline solution to form a saponified extractant (saponified product). Compared with organic carboxylic acid extractant, the saponified extractant has stronger surface activity and can form a stable water / oil microemulsion type organic phase. At the same time, the alkaline solution can play a role in adjusting the pH of the microreactor. The samarium-containing solution was extracted with a partially saponified extractant to obtain a hafnium-containing organic phase. The remaining saponified extractant is mixed with a fluorine-containing solution to form a water / oil microemulsion-type organic phase. The rhenium-containing organic phase and the fluorine-containing mixed solution undergo a precipitation reaction to obtain rhenium fluoride.

In a preferred embodiment, the alkaline solution is an alkaline solution (aqueous alkali solution), and the fluorine-containing compound is one or more of NaF, KF, and hydrofluoric acid.

Saponification reaction between lye and organic carboxylic acid extractant to obtain saponified extractant; extracting part of saponified extractant with rhenium-containing solution to obtain rhenium-containing organic phase; mixing the remaining saponified extractant with fluorine-containing compound to obtain Fluorine mixed solution, the fluorine-containing solution is one or more of NaF, KF and hydrofluoric acid; the rhenium-containing organic phase is subjected to a precipitation reaction with the above-mentioned mixed solution to obtain submicron-level rhenium fluoride.

Organic carboxylic acid extractant has surface activity due to its special hydrophilic and lipophilic special structure. Unreacted organic carboxylic acid extractant in the organic phase reacts with lye to form a saponified extractant (saponified product, first water / oil Microemulsion type organic phase). Compared with the organic carboxylic acid extractant, the saponified extractant has stronger surface activity and can form a stable water / oil microemulsion type organic phase (microreactor). At the same time, the lye can play a role in adjusting the pH of the microreactor. The samarium-containing solution was extracted with a partially saponified extractant to obtain a hafnium-containing organic phase (a second water / oil microemulsion type organic phase). The remaining saponified extractant is mixed with a fluorine-containing compound to form a fluorine-containing mixed solution (the third water / oil microemulsion type organic phase). A precipitation reaction occurs between the rhenium-containing organic phase and the above-mentioned fluorine-containing mixed solution to obtain submicron-level rhenium fluoride.

The reaction principle of the above reaction is:

The saponification reaction is: HA _(o) + NaOH → NaA _(o) + H ₂ O, HA _(o) is an organic carboxylic acid, and NaA _(o) is a saponified organic carboxylic acid extractant.

The extraction reaction is: Sc ³⁺ + 3NaA _(o) → ScA _{3 (o)} + 3Na ⁺ _(o)

The reaction for the formation of europium fluoride precipitation is: ScA _{3 (o)} + 3NaF → ScF ₃ ↓ + 3NaA _(o) .

In the above preparation process, the size of the microreactor of the water / oil microemulsion is in the micrometer and nanometer range, the middle is a 'small pool', and the shape is spherical, nearly spherical or ellipsoidal. During the saponification reaction, the lipophilic end (ie, alkane chain) of the organic carboxylic acid extractant extends to the oil phase, and the hydrophilic end (ie, carboxyl group) extends to the pool and gathers on the surface of the small pool. The stronger surface activity makes the microreactor formed more stable. Through the internal capacity of the microreactor, the purpose of adjusting the particle size of thorium fluoride can be achieved.

The method for preparing sub-micron-grade rhenium fluoride powder provided by the present application has the characteristics of simplicity and high efficiency. The rhenium is extracted and enriched from the solution and separated from impurity ions. The extractant also plays the role of forming a microreactor and stabilizing the powder form. The method can regulate the size, morphology and properties of products, and is more conducive to application in industrial production.

In another preferred embodiment, the alkaline solution is ammonia and the fluorine-containing compound is ammonium fluoride.

The organic carboxylic acid extractant has surface activity due to its special hydrophilic and lipophilic structure. The unreacted organic carboxylic acid extractant in the organic phase reacts with ammonia water to form a saponified extractant (saponified product, first water / oil micro Emulsion type organic phase). Compared with organic carboxylic acid extractant, the saponified extractant has stronger surface activity and can form a stable water / oil microemulsion type organic phase. At the same time, ammonia can play a role in adjusting the pH of the microreactor. The samarium-containing solution was extracted with a partially saponified extractant to obtain a hafnium-containing organic phase (a second water / oil microemulsion type organic phase). The remaining saponified extractant is mixed with ammonium fluoride to form a third water / oil microemulsion type organic phase of a fluorine-containing mixed liquid). The rhenium-containing organic phase and the fluorine-containing mixed solution are subjected to a precipitation reaction to obtain micron-grade rhenium fluoride.

The reaction principle of the above reaction is:

The saponification reaction is: HA _(o) + NH ₄ OH → NH ₄ A _(o) + H ₂ O, HA _(o) is an organic carboxylic acid, and NH ₄ A _(o) is an ammonium saponified carboxylic acid extractant.

The extraction reaction is: Sc ³⁺ + 3NH ₄ A _(o) → ScA _{3 (o)} + 3NH ₄ ⁺ .

The ammonium fluoride hafnium double salt precipitation reaction is: ScA _{3 (o)} + 4NH ₄ F + H ₂ O → NH ₄ ScF ₄ · H ₂ O ↓ + 3NH ₄ A _(o) .

The ammonium fluoride hydrazone double salt precipitation dehydration and ammonium removal reactions are: NH ₄ ScF ₄ · H ₂ O → NH ₄ ScF ₄ + H ₂ O ↑, NH ₄ ScF ₄ → ScF ₃ + NH ₃ ↑ + HF ↑.

The method for preparing micron-grade rhenium fluoride powder provided by the present application has the characteristics of simplicity and high efficiency. Rhenium is extracted and enriched from the solution and separated from impurity ions. The extractant also plays a role of forming a microreactor and stabilizing the powder form. The method can regulate the size, morphology and properties of the product. The NH ₄ ScF ₄ · H ₂ O double salt precipitated crystals formed by the reaction have good morphology, are hydrophilic, and can be easily separated from the liquid system. In the process of ammonium removal, the decomposition NH ₃ and HF gas are generated, and the generation of ScOF of fluorinated osmium oxide is inhibited, thereby ensuring the purity of the generated anhydrous rhenium fluoride. More conducive to the application of industrial production.

Preferably, the concentration of the organic carboxylic acid extractant is 0.5 to 3.5 mol / L. In the saponification reaction, the degree of ammonium saponification of the organic carboxylic acid extractant is 50 to 90%.

Preferably, the concentration of europium ions in the europium-containing solution during the extraction is 0.001 to 1.0 mol / L.

Preferably, when using a carboxylic acid to extract europium ions, the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the solution is 3 or more and 20 or less.

In a preferred embodiment, before performing the saponification reaction, the preparation method further includes: mixing an alkaline solution, an organic carboxylic acid extractant, and a phase regulator to obtain a reactant; and performing a saponification reaction on the reactant. To obtain a saponified extractant (saponified product, first water / oil microemulsion type organic phase).

In the present application, "alkali solution" refers to an aqueous solution of an alkali, and the above-mentioned alkali includes, but is not limited to, sodium hydroxide, potassium hydroxide, and the like.

The organic phase of the water / oil microemulsion can be formed after the saponification reaction, and the addition of a phase regulator is beneficial to make the formed water / oil microemulsion more stable. And during the saponification reaction, a microreactor capable of simultaneously adsorbing an extractant and a phase regulator can be formed. The shape, particle size, and properties of the microreactor can regulate the size, morphology, and properties of the product.

In a preferred embodiment, the reactants are prepared by the following methods: mixing an organic carboxylic acid extractant, a phase regulator, and an organic solvent to obtain an organic solution of the extractant; and mixing an organic solution of the extractant and an alkaline solution To obtain the reactant.

An organic solution of the extractant is first prepared, and then it is subjected to a saponification reaction with an alkaline solution, which is conducive to adjusting the concentration of the organic carboxylic acid extractant during the saponification reaction, thereby adjusting the extraction efficiency.

Preferably, the organic solvent is an alkane. More preferably, the organic solvent includes, but is not limited to, one or more of n-octane, n-heptane, n-hexane, cyclohexane, and kerosene.

The organic solvent may be an organic solvent commonly used in the art. In a preferred embodiment, the organic carboxylic acid extractant is an organic substance containing a carboxyl group, and is preferably one or more of a linear alkane carboxylic acid, an aromatic carboxylic acid, and a cyclic alkane carboxylic acid.

Preferably, the chain alkane carboxylic acid includes, but is not limited to, one or more of n-hexanoic acid, n-decanoic acid, dodecyl carboxylic acid, and isooctanoic acid; preferably, the aromatic hydrocarbon carboxylic acid includes, but is not limited to, secondary octanoic acid Phenylphenoxyacetic acid (CA-12) and / or sec-nonylphenoxyacetic acid; preferably, the cyclic alkane carboxylic acid is selected from carboxylic acids containing cyclopentyl or cyclohexyl.

In a preferred embodiment, the concentration of the phase regulator in the organic solution of the extractant is 5-25 vol%. In the above preparation method, the concentration of the phase regulator in the organic solution of the extractant includes, but is not limited to, the above range, and limiting it to the above range is beneficial to further improving the extraction efficiency and thus the yield of the submicron gadolinium fluoride.

Preferably, the phase modifier is an alkyl alcohol, and more preferably, the phase modifier includes, but is not limited to, one or more of n-butanol, n-hexanol, n-octanol, and isooctanol.

In a preferred embodiment, the concentration of the organic carboxylic acid extractant in the organic solution of the extractant is 0.5 to 3.5 mol / L. The extraction mechanism is a cation exchange mechanism. The concentration of the organic carboxylic acid extractant includes, but is not limited to, the above range, and is limited to the above range.

In a preferred embodiment, in the organic solution of the extractant, the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution is denoted as A, and 3 ≦ A ≦ 20. The ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of scandium ions in the scandium-containing solution includes, but is not limited to, the above range, and limiting it to the above range is beneficial to further improve the extraction rate of scandium ions.

In a preferred embodiment, during the precipitation reaction, the ratio of the amount of fluoride ions to the rhenium-containing substance in the rhenium-containing organic phase is denoted by B, and 4≤B≤6. The volume ratio of the water / oil microemulsion organic phase is 1:10 to 10: 1. The ratio of the amount of fluoride ion to the amount of thorium element in the thorium-containing organic phase and the volume ratio of the thorium-containing organic phase to the water / oil microemulsion type organic phase containing thionium include, but are not limited to, the above ranges, and are limited to Within the above range, it is beneficial to further increase the precipitation rate of thorium fluoride, and further improve the yield of thorium fluoride.

In a preferred embodiment, the above-mentioned extraction process is performed under the conditions of pH 2 to 4. The pH of the reaction system during the extraction process includes, but is not limited to, the above range, and limiting it to the above range is beneficial to further improve the extraction efficiency of the europium ions.

In a preferred embodiment, the precipitation reaction further includes: sequentially performing thermal aging, solid-liquid separation, washing, and drying treatment on the product system of the precipitation reaction to obtain submicron fluorene fluoride;

According to the different particle sizes of rhenium fluoride, the processes of heat preservation aging, solid-liquid separation, washing and drying treatment are also different. In a preferred embodiment, the sub-micron erbium fluoride is prepared by the following process: the temperature during the heat preservation and precipitation process is 90 to 150 ° C., and the time is 1 to 8 hours. Limiting the temperature and time of the heat preservation treatment process within the above-mentioned range is beneficial to further improve the yield of sub-micron fluorene. Preferably, the temperature during the drying process is 90 to 105 ° C. Limiting the temperature of the drying process to the above range is beneficial to improve the removal rate of water and further improve the yield of europium fluoride. Preferably, in the washing process, ethanol and / or water is used to wash the gadolinium fluoride precipitate, which is beneficial to reducing the loss rate of the gadolinium fluoride double salt during the washing process, thereby increasing the yield of gadolinium fluoride.

In another preferred embodiment, micron-sized europium fluoride is prepared by the following process:

In a preferred embodiment, the precipitation reaction further includes: sequentially performing thermal aging, solid-liquid separation, and drying on the product system of the precipitation reaction to obtain ammonium fluoride rhenium double salt precipitation; and sequentially ammonium fluoride rhenium double salt precipitation Carry out washing and dehydration deammonia treatment to obtain micron-grade rhenium fluoride;

The ammonium fluoride hafnium double salt precipitation reaction is: ScA _{3 (o)} + 4NH ₄ F + H ₂ O → NH ₄ ScF ₄ · H ₂ O ↓ + 3NH ₄ A _(o) .

The ammonium fluoride hydrazone double salt precipitation dehydration and ammonium removal reactions are: NH ₄ ScF ₄ · H ₂ O → NH ₄ ScF ₄ + H ₂ O ↑, NH ₄ ScF ₄ → ScF ₃ + NH ₃ ↑ + HF ↑.

The NH ₄ ScF ₄ · H ₂ O double salt precipitated crystals formed during the precipitation reaction have good morphology, with hydrated molecules, are hydrophilic, and are easily separated from the liquid phase system. During the ammonium removal process, the above-mentioned NH ₄ ScF ₄ · H ₂ O double salt is decomposed to generate NH ₃ and HF gas, which inhibits the formation of ScOF, and ensures the purity of the generated anhydrous rhenium fluoride.

Preferably, the temperature during the heat preservation and sedimentation process is 80 to 120 ° C, and the time is 1 to 4 hours. Limiting the temperature and time of the heat preservation treatment process within the above-mentioned range is beneficial to further improve the yield of micron-sized europium fluoride. Preferably, the temperature during the drying process is 90 to 105 ° C.

Preferably, the temperature of the dehydration and deamination process is 300 to 400 ° C, and the time is 2 to 4 hours. Limiting the temperature and time of the dehydration and deamination treatment process to the above-mentioned ranges is conducive to improving the water and ammonia gas and the removal rate, thereby improving the yield of thorium fluoride.

Preferably, in the washing process, ethanol and / or water is used to wash the ammonium fluoride rhenium double salt precipitate, which is beneficial to reducing the loss rate of the ammonium fluoride rhenium double salt during the washing process, thereby increasing the yield of the rhenium fluoride.

Aiming at the technical problems existing in the prior art for extracting thorium oxide, another exemplary embodiment of the present invention provides a method for extracting thorium fluoride. The method includes the following steps: The above preparation method includes: the organic extractant is an organic solvent solution containing an acidic organic phosphorus extractant, the thorium-containing solution is a thallium-containing inorganic acid solution, and the thallium-containing inorganic acid is treated with the organic solvent solution containing the acidic organic phosphorus extractant. The solution is subjected to tritium extraction to obtain a tritium-containing, organic phase; S2, the tritium-containing organic phase is washed to remove impurities; S3, the fluorine-containing mixed solution is a HF and / or NaF solution, and the tritium-containing organic phase is removed after the impurities are removed Fluorine-containing mixed liquid is added for back extraction. After the liquid-liquid separation, the complex anion solution and the unloaded organic phase are obtained. The hydrochloric acid is added to the complex anion solution to adjust the pH of the solution to form ScF ₃ precipitate. After solid-liquid separation, ScF _{3 is} obtained. Precipitation and precipitation mother liquor; S4, ScF ₃ precipitate was washed and dried to obtain europium fluoride.

The extraction reaction is (HA stands for extractant, and subscript _(o) stands for organic phase):

Sc ³⁺ + 3HA _(o) → ScA _{3 (o)} + 3H ⁺

The precipitation back extraction reaction is:

ScA _{3 (o)} + 3NaF → 3NaA _(o) + ScF ₃ ↓, ScA _{3 (o)} + 3HF → 3HA _(o) + ScF ₃ ↓

An organic phase containing an acidic organic phosphorus extractant (an organic solvent solution containing an acidic organic phosphorus extractant) is used to perform a rhenium extraction treatment on a rhenium-containing material solution (a rhenium-containing inorganic acid solution) to obtain a supported organic phase containing rhenium;钪 Organic phase washing treatment to remove impurities that are extracted at the same time; the above-removed organic phase is added to HF and / or NaF solution for back extraction in order to generate ScF ₃ precipitate; and the generated Fluorine fluoride precipitate is washed And drying to produce a rhenium fluoride product. This method can effectively enrich and extract thorium fluoride from thorium-containing solution.

Preferably, in S3, the ratio of the amount of F ^- ions in the HF and / or NaF solution to the rhenium substance in the rhenium-containing inorganic acid solution is greater than 3 and less than 4.5, and the rhenium is sufficiently precipitated out.

Preferably, the acidic organic phosphorus extractant is one or more selected from the group consisting of bis (2-ethylhexyl) phosphoric acid, 2-ethylhexyl phosphate mono-2-ethylhexyl ester, and Cyanex272 extractant; The organic extractant in the organic solvent solution of the acidic organic phosphorus extractant is at least one of alkanes or mixtures thereof, or aromatic hydrocarbons having a density less than water; more preferably, the alkanes or mixtures thereof include n-heptane, N-hexane and kerosene; more preferably, aromatic hydrocarbons include benzene and toluene.

In order to further optimize the performance of the extractant, the concentration of the acidic organic phosphorus extractant in the organic solvent solution (also referred to as the extractant) containing the acidic organic phosphorus extractant is 0.01 mol / L to 4 mol / L.

According to a typical embodiment of the present invention, the scandium-containing inorganic acid solution is a scandium-containing sulfuric acid solution, a hydrochloric acid solution, or a nitric acid solution. Of course, the scandium-containing inorganic acid solution may contain other metal ions, such as Ca ²⁺ , Mg ²⁺ , Mn ²⁺ , Ni ²⁺ , Al ³⁺ , Fe ³⁺ , Cr ³⁺ .

Preferably, the volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the osmium-containing inorganic acid solution is (1:20) to (1: 1), and in this range of ratio, the rhenium is fully and efficiently extracted. . Preferably, the volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the HF and / or NaF solution in S3 is (1:20) to (20: 1).

According to a typical embodiment of the present invention, S4 includes: washing the ScF ₃ precipitate with ethanol and water, respectively, so as to remove organic matters adsorbed on the surface and water-soluble impurities, respectively. Preferably, the ethanol washing temperature is 20-40 ° C, and the water washing temperature is 50-90 ° C.

Preferably, in S2, the washing solution used is a 0.1 to 2 mol / L hydrochloric acid aqueous solution or a 0.1 to 1 mol / L sulfuric acid aqueous solution.

According to a typical embodiment of the present invention, the precipitated mother liquor in S3 is added to HF and / or NaF and returned to the back extraction treatment step, and the unloaded organic phase is returned to S1 to be used in the radon extraction treatment step, which is beneficial to the full recycling of raw materials. ,reduce manufacturing cost.

According to a typical embodiment of the present invention, the mixing process of mechanical stirring is used in both the mash extraction and the back extraction process to accelerate the reaction progress.

Preferably, the reaction temperature of the back extraction is 20 to 70 ° C, and preferably 25 to 45 ° C.

Preferably, in S1, the ratio of the amount of the acidic organic phosphorus extractant in the organic solvent solution containing the acidic organic phosphorus extractant to the thorium substance in the thorium-containing inorganic acid solution is greater than 3 and less than 20, and in this range of ratios, it is favorable for the thallium. Fully and efficiently extracted.

Preferably, the temperature at which SmF is precipitated and dried in S4 to generate a HfF product is 90-105 ° C.

According to a typical embodiment of the present invention, as shown in FIG. 1, the method includes: performing an rhenium extraction treatment with an organic relative to a rhenium-containing feed liquid containing an acidic organic phosphorus extractant, so as to obtain a supported organic phase containing rhenium and control the extraction Reaction conditions such as agent concentration, and the volume of the organic phase is smaller than the volume of the aqueous phase, so that the plutonium is enriched and reacted with impurity ions (such as Ca ²⁺ , Mg ²⁺ , Mn ²⁺ , Ni ²⁺ , Al ³⁺ , Fe ^{3 +} , Cr ³⁺ ) separation; from the lutetium-containing organic phase by washing treatment, a small amount of impurity ions that are simultaneously extracted or entrained can be removed to further purify the lutetium; the above-removed organic phase is added to HF, NaF solution for precipitation Back-extraction to generate ScF ₃ precipitates of osmium fluoride, research has found that by controlling reaction conditions such as the concentration of precipitated back-extractant, temperature, and organic phase / aqueous phase volume ratio, the back extraction efficiency is high and the organic phase is separated from the aqueous phase. The generated fluorene fluoride precipitate (ScF ₃ ) has high precipitation efficiency and facilitates the next filtration; the fluorene fluoride precipitate is washed with ethanol and water at a selected temperature, respectively, to remove the organic matter adsorbed on the surface and Water soluble The erbium is further purified, and the erbium fluoride precipitate after washing has better filtering performance; the generated erbium fluoride is washed, and the precipitate is dried to generate the erbium fluoride product. When back-extracting with HF and NaF solutions, the tritium extracted into the organic phase under optimized conditions (including concentration, temperature, organic phase: volume ratio of water phase) with HF and NaF to form tritium fluoride precipitation (ScF ₃ ), Rhenium fluoride can form a better crystalline form with strong hydrophilicity. Rhenium easily enters the aqueous solution in the form of a precipitate, which makes the back extraction efficiency high, and the organic phase and the water phase have a good separation effect. It can be applied in a mixed clarification extraction tank. The continuous operation of extraction and separation, the precipitation of thorium fluoride can be separated by traditional solid-liquid separation equipment, and therefore, it is advantageous for industrial production.

The following further describes the present application in detail with reference to specific embodiments, which cannot be understood as limiting the scope of protection claimed by the present application.

(1) Preparation of submicron erbium fluoride

Example 1

In the extraction reactor, 1000 mL of a kerosene solution containing 1 mol / L CA-12 extractant and 10% n-butanol (phase modifier) was added, and a solution of sodium hydroxide was added to cause a saponification reaction of CA-12 to obtain a saponified extractant. (The first water / oil microemulsion type organic phase), the degree of saponification was 90%.

500 mL of the first water / oil microemulsion organic phase was mixed with 500 mL of a rhenium chloride solution containing 0.25 mol / L of rhenium to extract the rhenium in the rhenium-containing hydrochloric acid solution, and the pH of the rhenium-containing solution extraction endpoint was controlled with a sodium hydroxide solution It was 2.5, and the raffinate was separated and removed to obtain a second water / oil microemulsion type organic phase (an organic phase containing rhenium), and the extraction rate of rhenium was 99.0 wt%.

100 mL of a 4 mol / L sodium fluoride solution was added to 500 mL of the first water / oil microemulsion type organic phase to form a mixed solution (third water / oil microemulsion type organic phase);

The above-mentioned second water / oil microemulsion type organic phase and the third water / oil microemulsion type organic phase are mixed to cause a precipitation reaction. The product system of the precipitation reaction is subjected to a heat preservation treatment at 200 ° C for 4 hours, and centrifuged with a high-speed centrifuge and Solid-liquid separation treatment to obtain sub-micron rhenium fluoride powder with a surface adsorbed by an extractant and a phase modifier. The above-mentioned submicron rhenium hydrofluoride powder adsorbed with the extractant and the phase regulator was washed twice with 40 ° C ethanol and 60 ° C water; dried in a drying cabinet at 90 ° C to obtain 37.2g of submicron rhenium fluoride powder. The total yield of fluorene was 98.1 wt%. The particle size of the powder was 0.2-0.5 μm as measured by a transmission electron microscope.

Among them, the "extractant organic solution is 1mol / L CA-12 extractant-10% n-butanol kerosene solution" refers to the use of CA-12 extractant and n-butanol regulator as the solute, kerosene solution as the solvent, and extraction The volume percentage of n-butanol in the organic solvent was 10%.

Example 2

In an extraction reactor, use 1000 mL of a n-heptane solution containing 3 mol / L naphthenic acid extractant-20% isooctanol (phase modifier), add a solution of sodium hydroxide and a naphthenic acid extractant to undergo a saponification reaction, A saponified extractant (first water / oil microemulsion type organic phase) was obtained with a degree of saponification of 60%.

500 mL of the first water / oil microemulsion organic phase was mixed with 500 mL of rhenium chloride solution containing 0.1 mol / L of rhenium to extract the rhenium in the rhenium-containing hydrochloric acid solution, and the pH of the rhenium-containing solution extraction endpoint was controlled with a sodium hydroxide solution The ratio was 3.5, and the raffinate was separated and removed to obtain a second water / oil microemulsion type organic phase (an organic phase containing rhenium), and the extraction ratio of rhenium was 99.5% by weight.

500 mL of the first water / oil microemulsion type organic phase was added to 50 mL of a 6.8 mol / L hydrofluoric acid solution to form a mixed solution (third water / oil microemulsion type organic phase).

The above-mentioned second water / oil microemulsion type organic phase and the third water / oil microemulsion type organic phase are mixed to cause a precipitation reaction. The reaction system of the precipitation reaction is subjected to a heat preservation treatment at 150 ° C. for 8 hours, and centrifuged with a high-speed centrifuge and Solid-liquid separation treatment to obtain sub-micron rhenium fluoride powder with a surface adsorbed by an extractant and a phase modifier. The above-mentioned submicron fluorinated rhenium powder adsorbed with the extractant and the phase modifier was washed twice with ethanol and water; dried at 105 ° C to obtain a submicron fluorinated rhenium powder. The total yield of rhenium was 98.1% . The particle size of the powder was measured by transmission electron microscope to be 0.5 to 1 μm.

The "extractant organic solution is 3mol / L naphthenic acid extractant-20% isooctanol in n-heptane solution" refers to the use of naphthenic acid extractant and isooctanol regulator as the solute, and n-heptane solution as the solute The volume percentage of isooctanol in the organic solution of the solvent and the extractant was 20%.

Example 3

The difference from Example 1 is that the extractant is n-hexanoic acid.

The total yield of osmium was 99.1 wt%. The particle size of the powder was measured by transmission electron microscope to be 0.1-0.3 μm.

Example 4

The difference from Example 1 is that the concentration of the phase modifier in the organic solution of the extractant is 1 vol%.

The total yield of rhenium was 88.3 wt%. The particle size of the powder was 0.4-0.6 μm as measured by a transmission electron microscope.

Example 5

The difference from Example 1 is that the concentration of the organic carboxylic acid extractant in the organic solution of the extractant is 4 mol / L.

The total yield of rhenium was 86.9 wt%. The particle size of the powder was measured by transmission electron microscope to be 0.5-0.6 μm.

Example 6

The difference from Example 1 is that the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution is 1: 1.

The total yield of rhenium was 90.2% by weight. The particle size of the powder was 0.1-0.2 μm as measured by a transmission electron microscope.

Example 7

The difference from Example 1 is that the pH of the reaction system was adjusted to 5 during the extraction process.

The total yield of rhenium was 93.5% by weight. The particle size of the powder was 0.3-0.7 μm by transmission electron microscope.

Example 8

The difference from Example 1 is that the temperature during the heat preservation and sedimentation process is 80 ° C. and the time is 10 h.

The total yield of rhenium was 91.1 wt%. The particle size of the powder was 0.6-1 μm as measured by a transmission electron microscope.

Comparative Example 1

After directly mixing 1000 mL of the first water / oil microemulsion organic phase, 500 mL of a rhenium chloride solution containing 0.25 mol / L of rhenium, and 100 mL of a 4 mol / L sodium fluoride solution, a precipitation reaction occurred. The product system of the precipitation reaction was Incubation treatment was performed at 200 ° C for 4 hours, and the mixture was centrifuged with a high-speed centrifuge and subjected to solid-liquid separation treatment to obtain a sub-micron rhenium fluoride powder with a surface adsorbed by an extractant and a phase modifier. The above-mentioned submicron rhenium hydrofluoride powder containing the extractant and the phase modifier was washed twice with ethanol 40 ° C and water 60 ° C, respectively; dried in a drying cabinet at 90 ° C, the yield was 62% by weight, and detected by transmission electron microscope Its powder particle size is 5 to 8 μm.

From the above description, it can be seen that the foregoing embodiments of the present invention achieve the following technical effects:

It can be seen from comparing Examples 1 to 8 and Comparative Example 1 that the preparation method provided by the present application is beneficial to increase the yield of rhenium fluoride and reduce its particle size.

It can be seen from comparing Examples 1 to 3 and Comparative Example 1 that the preparation method of rhenium fluoride provided by the present application is beneficial to improve the yield of submicron erbium fluoride.

Comparing Examples 1 and 4, it can be seen that limiting the concentration of the phase regulator in the organic solution of the extractant to the preferred range of the present application is beneficial to improving the yield of the submicron rhenium fluoride.

Comparing Examples 1 and 5, it can be seen that limiting the concentration of the organic carboxylic acid extractant in the organic solution of the extractant to the preferred range of the present application is beneficial to improving the yield of submicron fluorene.

Comparing Examples 1 and 6, it can be seen that limiting the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution within the preferred range of the present application is beneficial to improving the yield of submicron-level europium fluoride.

Comparing Examples 1 and 7, it can be seen that limiting the pH of the reaction system during the extraction process to the preferred range of the present application is beneficial to improving the yield of submicron fluorene.

Comparing Examples 1 and 8, it can be seen that limiting the temperature and time during the heat preservation and precipitation process to the preferred ranges of the present application is beneficial to improving the yield of submicron rhenium fluoride.

In addition, the method for preparing submicron erbium fluoride powder provided by this application has the following advantages: (1) Enrichment, extraction and purification as a whole to shorten the process: first, the erbium is extracted and enriched from the solution and separated from impurity ions by the extraction method. To purify the role of radon. (2) Controlling the particle size of the precipitation: the use of organic carboxylic acid extractants to form a stable water / oil microemulsion organic phase, and the use of microreactors adsorbed by the extractants and phase regulators, (3) the back extraction precipitation is shortened as a whole Process: Back extraction simultaneously produces submicron ammonium fluoride ammonium hafnium double salt precipitation powder whose surface is adsorbed by the extractant and phase regulator. The double salt precipitation crystals are easy to separate. (4) The product has uniform particle size and high purity: extractant and phase The conditioner can prevent powder agglomeration and stabilize the powder form, and further inhibit the generation of thorium oxyfluoride during the dehydration and ammonium removal process, so as to generate a high-purity submicron level thorium fluoride powder.

(2) Preparation method of micron-grade europium fluoride

Example 1

In the extraction reactor, add 1000 mL of a kerosene solution containing 1 mol / L sec-octylphenoxyacetic acid-10% n-butanol (phase modifier), and then add ammonia and sec-octylphenoxyacetic acid (CA-12) The saponification reaction occurred to obtain a saponified extractant (the first water / oil microemulsion type organic phase), and the degree of saponification was 90%.

500 mL of saponified extractant is mixed with 500 mL of rhenium chloride solution containing 0.3 mol / L of rhenium to extract the rhenium in the rhenium-containing hydrochloric acid solution, and the pH of the hydrazone-containing solution is controlled to be 2.5 with ammonia water, and the raffinate is separated and removed to obtain Tritium-containing organic phase (second water / oil microemulsion type organic phase);

To 500 mL of the above-mentioned first water / oil microemulsion type organic phase was added 80 mL of a 5 mol / L ammonium fluoride solution (wherein the molar ratio of fluoride ion to europium ion was 5.33) to form a fluorine-containing mixed solution (third water / oil micro Emulsion type organic phase).

After mixing the second water / oil microemulsion type organic phase and the third water / oil microemulsion type organic phase, heat preservation treatment was performed at 100 ° C for 2 hours, and the mixture was centrifuged with a high-speed centrifuge and subjected to solid-liquid separation treatment to obtain the surface being extracted. Complex salt precipitation powder adsorbed by agents and phase modifiers. The double salt precipitation powder was washed twice with ethanol 30 ° C and water 60 ° C twice, and dried in a drying box at 90 ° C to remove free water. The dried double salt precipitation powder was heated at 400 ° C for 2h, and dehydrated to remove ammonium. Micron-grade anhydrous rhenium fluoride powder was formed with a yield of 99.3 wt%. The particle size of the powder was 2-5 μm as measured by a transmission electron microscope.

Among them, the "extractant organic solution is 1mol / L CA-12 extractant-10% n-butanol kerosene solution" means that CA-12 and n-butanol are used as solutes, kerosene solution is used as a solvent, and The volume percentage of butanol was 10%.

Example 2

In the extraction reactor, add 1000 mL of a n-heptane solution containing 3 mol / L naphthenic acid extractant-20% isooctanol (phase modifier), add ammonia water and naphthenic acid extractant to undergo a saponification reaction to obtain a saponified extractant (First water / oil microemulsion type organic phase), the degree of saponification was 60%.

500 mL of saponified extractant was mixed with 500 mL of a rhenium chloride solution containing 0.3 mol / L of rhenium to extract rhenium in a rhenium-containing hydrochloric acid solution, and the pH of the hydrazone-containing solution was controlled to pH 3.5 with ammonia, and the raffinate was separated and removed to obtain Rhenium-containing organic phase (second water / oil microemulsion type organic phase).

To 500 mL of the saponified extractant, 40 mL of an 8 mol / L ammonium fluoride solution was added to form a fluorine-containing mixed solution (the third water / oil microemulsion type organic phase).

After mixing the second water / oil microemulsion type organic phase and the third water / oil microemulsion type organic phase, heat preservation treatment was performed at 120 ° C for 4 hours, and the mixture was centrifuged with a high-speed centrifuge and subjected to solid-liquid separation treatment to obtain the surface being extracted. Complex salt precipitation powder adsorbed by agents and phase modifiers. The above-mentioned double salt precipitation powder was washed twice with ethanol 40 ° C and water 90 ° C twice, and dried in a drying box at 100 ° C to remove free water. The dried double salt precipitation powder was heated at 350 ° C for 4h, and dehydrated and ammonium removed to Micron-sized anhydrous rhenium fluoride powder was formed, with a yield of 98.5% by weight. The particle size of the powder was 5-9 μm as measured by a transmission electron microscope.

The "extractant organic solution is 3mol / L naphthenic acid extractant-20% isooctanol in n-heptane solution" means that the naphthenic acid extractant and isooctanol are used as the solute, and the n-heptane solution is used as the solvent, At the same time, the volume percentage of isooctanol in the organic solution of the extractant was 20%.

Example 3

The difference from Example 1 is that the extractant is n-hexanoic acid.

The total yield of osmium is 95% by weight, and the particle size of the powder is 4-7 μm by transmission electron microscopy.

Example 4

The difference from Example 1 is that the concentration of the phase modifier in the organic solution of the extractant is 1 vol%.

The total yield of rhenium was 94% by weight, and the particle size of the powder was 2-6 μm as measured by a transmission electron microscope.

Example 5

The difference from Example 1 is that the concentration of the organic carboxylic acid extractant in the organic solution of the extractant is 4 mol / L.

The total yield of osmium was 98.7% by weight, and the particle size of the powder was 2-6 μm as measured by a transmission electron microscope.

Example 6

The difference from Example 1 is that the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution is 1: 1.

The total yield of osmium was 92% by weight, and the particle size of the powder was 3-6 μm by transmission electron microscopy.

Example 7

The difference from Example 1 is that the pH of the reaction system was adjusted to 5 during the extraction process.

The total yield of osmium was 93% by weight, and the particle size of the powder was 3-5 μm as measured by a transmission electron microscope.

Example 8

The difference from Example 1 is that the temperature during the heat preservation and sedimentation process is 150 and the time is 2 hours.

The total yield of osmium is 97.4% by weight, and the particle size of the powder is 6-8 μm by transmission electron microscopy.

Comparative Example 1

After directly mixing 1000 mL of saponified extractant, 500 mL of dysprosium chloride solution containing 0.3 mol / L of dysprosium, and 80 mL of 5 mol / L ammonium fluoride solution, incubate at 100 ° C for 2 hours, centrifuge and solid-liquid with a high-speed centrifuge The separation treatment yields a double salt precipitated powder whose surface is adsorbed by the extractant and the phase modifier. The double salt precipitation powder was washed twice with ethanol 30 ° C and water 60 ° C twice, and dried in a drying box at 90 ° C to remove free water. The dried double salt precipitation powder was heated at 400 ° C for 2h, and dehydrated to remove ammonium. Micron-grade anhydrous rhenium fluoride powder was formed with a yield of 58% by weight. The particle size of the powder was 10-15 μm as measured by a transmission electron microscope.

From the above description, it can be seen that the foregoing embodiments of the present invention achieve the following technical effects:

It can be seen from comparing Examples 1 to 8 and Comparative Example 1 that the preparation method provided by the present application is beneficial to increase the yield of rhenium fluoride and reduce its particle size.

Comparing Examples 1 to 3 and Comparative Example 1, it can be seen that the preparation method of thorium fluoride provided by the present application is beneficial to improve the yield of micron-level thorium fluoride.

Comparing Examples 1 and 4, it can be known that limiting the concentration of the phase regulator in the organic solution of the extractant within the preferred range of the present application is beneficial to improving the yield of micron-sized europium fluoride and saving the amount of reagents.

Comparing Examples 1 and 5, it can be seen that limiting the concentration of the organic carboxylic acid extractant in the organic solution of the extractant to the preferred range of the present application is beneficial to improving the yield of micron-sized europium fluoride.

Comparing Examples 1 and 6, it can be seen that limiting the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution within the preferred range of the present application is beneficial to improving the yield of micron-level europium fluoride.

Comparing Examples 1 and 7, it can be known that limiting the pH of the reaction system during the extraction process to the preferred range of the present application is beneficial to improving the yield of micron-sized europium fluoride.

Comparing Examples 1 and 8, it can be known that limiting the temperature and time during the heat preservation and precipitation process to the preferred ranges of the present application is beneficial to improving the yield of micron-sized europium fluoride.

In addition, the method for preparing micron-grade europium fluoride powder provided by the present application has the following advantages: (1) enrichment, extraction, and purification as a whole to shorten the process: the extraction method firstly extracts and concentrates the europium from the solution and separates it from impurity ions, The effect of purifying tritium. (2) Controlling the particle size of the precipitation: using the organic carboxylic acid extractant to form a stable water / oil microemulsion, and using the microreactor adsorbed by the extractant and the phase regulator, (3) back-extracting and precipitation as a whole Extraction simultaneously produces micron-level ammonium fluoride rhenium double salt precipitation powder with surface adsorbed by the extractant and phase modifier. The double salt precipitation crystals are easy to separate. (4) The product has a uniform particle size and high purity: the extractant and phase modifier can prevent The powder agglomerates to stabilize the morphology of the powder, and further inhibits the generation of thorium oxyfluoride during the dehydration and ammonium removal process, so as to produce a high-purity micron-level anhydrous thorium fluoride powder.

(Three) the preparation of thorium fluoride

Example 1

P507 extractant (2-ethylhexyl phosphate mono-2-ethylhexyl ester), NaF back extraction

In a mixed clarification extraction tank, according to the volume ratio of organic solution and thorium-containing solution of 1: 1, a kerosene solution containing 1 mol / LP507 extractant was used, from a solution containing 0.3 mol / L of thorium chloride and 1 mol / L hydrochloric acid. Mixing to extract radon from the radon-containing solution;

Washing the organic phase containing tritium with a 1 mol / L hydrochloric acid aqueous solution to remove co-extracted impurity elements;

According to the volume ratio (volume ratio of organic solution and aqueous solution) of the organic solution of the extractant and the stripping agent solution is 1: 1, the organic phase loaded with tritium after washing and the stripping agent aqueous solution (aqueous phase) containing 1mol / L NaF Mix at a reaction temperature of 50 ° C to perform a back-extraction reaction. The generated lutetium fluoride precipitate is in the aqueous phase and flows out from the aqueous phase outlet; the organic phase of the unloaded rhenium is separated from the solution and returned to the extraction step for recycling;

The generated hafnium hydrofluoride precipitate was separated from the aqueous phase by vacuum filtration to obtain an enriched hafnium fluoride precipitate; the hafnium fluoride precipitation mother liquor was added to NaF and returned to the hafnium back-extraction treatment step; the hafnium fluoride precipitation was separately used in ethanol Wash with water at 30 ° C and 80 ° C to remove organic matter and water-soluble impurities adsorbed on the surface, respectively.

The scandium fluoride ScF ₃ precipitate is dried at 100 ° C. to generate a scandium fluoride product, in which the scandium extraction recovery can reach 95%.

Example 2

P204 extractant (bis (2-ethylhexyl) phosphoric acid), HF back extraction

In a reaction kettle with agitation and mixing, according to the volume ratio of the organic solution and the rhenium-containing solution of 1:10, a positive solution containing 1 mol / L (bis (2-ethylhexyl) phosphate) extractant (P204 extractant) was used. The heptane solution is used to extract rhenium from a solution containing 0.02 mol / L rhenium and 0.5 mol / L sulfuric acid; the organic phase containing rhenium is washed with a 0.5 mol / L sulfuric acid aqueous solution, and the volume of the organic solution of the extractant and the solution of the precipitated back-extracting agent is calculated The ratio (organic solution: aqueous solution volume ratio) is 10: 1. The washed lutetium-loaded organic phase is mixed with a 7 mol / LHF extractive agent aqueous solution (aqueous phase) to perform a back extraction reaction and generate rhenium fluoride Precipitation; the rubidium fluoride precipitate was washed with ethanol and water at 40 ° C and 90 ° C, respectively; the rubidium fluoride ScF3 precipitate was dried at 105 ° C to generate a rubidium fluoride product.

The organic phase of no-loaded tritium is separated from the precipitation back-extractant aqueous solution in a mixed clarification extraction tank. The generated tritium fluoride precipitate is in the aqueous phase and flows out from the aqueous phase outlet together with the precipitation mother liquor; The precipitation mother liquor is separated by a centrifuge to obtain an enriched rhenium fluoride precipitate, and the recovery rate of the rhenium can reach 93%.

Example 3

Cyanex272 extractant (bis (2,4,4-trimethylpentyl) phosphinic acid), HF back extraction

In a reaction kettle with stirring and mixing, according to a volume ratio of organic solution and thorium-containing solution of 1:20, a n-hexane solution containing 4mol / L Cyanex272 extractant was used from a solution containing 0.01mol / L of thorium and 1mol / L hydrochloric acid. Extract 钪; wash the organic phase loaded with 钪 with 1 mol / L hydrochloric acid aqueous solution, according to the volume ratio (organic solution: water solution volume ratio) of the organic solution of the extractant and the solution of the precipitation back-extractor is 10: 1, and load the washed load The organic phase of rhenium is mixed with a stripping agent aqueous solution (aqueous phase) containing 9mol / LHF to perform a back extraction reaction and generate a rhenium fluoride precipitate; the rhenium fluoride precipitate is washed with ethanol and water, and the washing temperature is 20 ° C And 90 ° C; the rhenium fluoride ScF3 precipitate was dried at 90 ° C to generate a rhenium fluoride product, and the recovery rate of rhenium could reach 91%.

Example 4

P204 extractant (bis (2-ethylhexyl) phosphoric acid), HF back extraction

In a reaction kettle with stirring and mixing, according to a volume ratio of 1: 1 of an organic solution and a rhenium-containing solution, use a kerosene solution containing 1 mol / LP507 extractant to extract from a solution containing 0.01 mol / L rhenium and 0.5 mol / L sulfuric acid.钪; Wash the organic phase containing tritium with 0.5 mol / L sulfuric acid aqueous solution, according to the volume ratio (organic solution: aqueous solution volume ratio) of the organic solution of the extractant and the precipitation back-extractant solution is 20: 1, and the load after washing is The organic phase of rhenium is mixed with a stripping agent aqueous solution (aqueous phase) containing 0.8mol / LHF to perform a back-extraction reaction and generate a rhenium fluoride precipitate; the rhenium fluoride precipitate is washed with ethanol and water respectively, and the washing temperature is 40 ℃ and 50 ℃; the ScF3 fluoride precipitate was dried at 105 ° C to produce fluorinated fluorinated products, and the recovery of rhenium could reach 92%.

Example 5

The difference from Implementation Case 1 is that

The extractant used is P507 and HF back extraction, and the generated erbium fluoride ScF ₃ precipitate is dried at 100 ° C. to generate a erbium fluoride product, in which the recovery rate of erbium extraction can reach 92%.

Implementation Case 6

Compared with implementation case 2, the difference is that

The extraction agent used is P204, NaF back extraction, and the generated erbium fluoride ScF ₃ precipitate is dried at 105 ° C. to produce a erbium fluoride product, wherein the recovery rate of the erbium extraction can reach 95%.

Implementation case 7

The difference from Implementation Case 1 is that

According to the volume ratio (organic solution, aqueous solution volume ratio) of the organic solution of the extractant and the stripping agent solution 1:10, the organic phase loaded with tritium after washing and the aqueous stripping agent solution (aqueous phase) containing 0.2mol / l NaF The mixing is performed at a reaction temperature of 50 ° C. to perform a back-extraction reaction. The generated lutetium fluoride precipitate is in the aqueous phase and flows out from the aqueous phase outlet; the organic phase of the unloaded rhenium is separated from the solution and returned to the extraction step for recycling;

The generated hafnium hydrofluoride precipitate was separated from the aqueous phase by vacuum filtration to obtain an enriched hafnium fluoride precipitate; the hafnium fluoride precipitation mother liquor was added to NaF and returned to the hafnium back-extraction treatment step; the hafnium fluoride precipitation was separately used in ethanol Wash with water at 30 ° C and 80 ° C to remove organic matter and water-soluble impurities adsorbed on the surface, respectively.

The rubidium fluoride ScF ₃ precipitate is dried at 100 ° C. to generate a rubidium fluoride product, wherein the recovery rate of the rubidium extraction can reach 90%.

Implementation Case 8

The difference from implementation case 2 is that

According to the volume ratio (organic solution, aqueous solution volume ratio) of the organic solution of the extractant and the stripping agent solution 1:20, the organic phase loaded with tritium after washing and the stripping agent aqueous solution (aqueous phase) containing 0.05mol / l of HF The mixing is performed at a reaction temperature of 50 ° C. to perform a back-extraction reaction. The generated lutetium fluoride precipitate is in the aqueous phase and flows out from the aqueous phase outlet; the organic phase of the unloaded rhenium is separated from the solution and returned to the extraction step for recycling;

The generated hafnium hydrofluoride precipitate was separated from the aqueous phase by vacuum filtration to obtain an enriched hafnium fluoride precipitate; the hafnium fluoride precipitation mother liquor was added to HF and returned to the hafnium back-extraction treatment step; the hafnium fluoride precipitates were respectively used in ethanol Wash with water at 30 ° C and 80 ° C to remove organic matter and water-soluble impurities adsorbed on the surface, respectively.

The scandium fluoride ScF ₃ precipitate was dried at 100 ° C. to generate a scandium fluoride product, and the recovery rate of the scandium extraction can reach 88%.

From the above description, it can be seen that the foregoing embodiment of the present invention achieves the following technical effects: The preparation of the thallium fluoride product by using the above method can shorten the process flow, reduce the consumption of raw materials, reduce operating costs, and is beneficial to industrial production.

The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (30)

1. A preparation method of thorium fluoride is characterized in that the preparation method includes:

   Extracting an organic extractant with a thorium-containing solution to obtain a thallium-containing organic phase;

   The hafnium-containing organic phase is subjected to a precipitation reaction with a fluorine-containing mixed solution to obtain the hafnium fluoride.
2. The preparation method according to claim 1, wherein the preparation method comprises:

   S1, the organic extractant is an organic solvent solution containing an acidic organic phosphorus extractant, the thorium-containing solution is a thallium-containing inorganic acid solution, and the thallium-containing inorganic acid solution is compared with the organic solvent solution containing the acidic organic phosphorus extractant Performing tritium extraction to obtain the tritium-containing, organic phase;

   S2: performing a washing treatment on the rhenium-containing organic phase to remove impurities;

   S3. The fluorine-containing mixed solution is an HF and / or NaF solution. The fluorine-containing mixed solution is added to the thorium-containing organic phase after the impurities are removed for back extraction. Carrying an organic phase, adding hydrochloric acid to the complex anion solution to adjust the pH of the solution to generate a ScF ₃ precipitate, and obtaining a ScF ₃ precipitate and a mother liquor after solid-liquid separation;

   S4, the said ScF _washed precipitate was dried to obtain the fluorinated scandium.
3. The preparation method according to claim 1, wherein the preparation method comprises:

   Performing a saponification reaction between an alkaline solution and an organic carboxylic acid extractant to obtain a saponified extractant, wherein the saponified extractant is the organic extractant;

   Extracting a part of the saponified extractant with the thorium-containing solution to obtain a thorium-containing organic phase;

   Mixing the remaining saponified extractant with a fluorine-containing compound to obtain the fluorine-containing mixed liquid;

   The rhenium-containing organic phase is subjected to a precipitation reaction with the fluorine-containing mixed solution to obtain the rhenium fluoride.
4. The preparation method according to claim 3, wherein the alkaline solution is an aqueous solution of a base, and the fluorine-containing compound is one or more of NaF, KF, and hydrofluoric acid.
5. The method according to claim 3, wherein the alkaline solution is aqueous ammonia and the fluorine-containing compound is ammonium fluoride.
6. The preparation method according to claim 4, wherein before the saponification reaction, the preparation method further comprises:

   Mixing the alkaline solution, the organic carboxylic acid extractant, and a phase regulator to obtain a reactant; and

   The saponification reaction is performed on the reactant to obtain the saponification extractant.
7. The preparation method according to claim 6, wherein the reactant is prepared by the following method:

   Mixing the organic carboxylic acid extractant, the phase regulator and an organic solvent to obtain an organic solution of the extractant;

   Mixing the organic solution of the extractant with the alkaline solution to obtain the reactant;

   Preferably, the organic solvent is an alkane, and more preferably one or more of n-octane, n-heptane, n-hexane, cyclohexane, and kerosene.
8. The preparation method according to claim 6 or 7, wherein the organic carboxylic acid extractant is an organic substance containing a carboxyl group, and is preferably a chain alkane carboxylic acid, an aromatic carboxylic acid, and a cyclic alkane carboxylic acid. One or more of

   Preferably, the alkanecarboxylic acid is selected from one or more of n-hexanoic acid, n-decanoic acid, dodecylcarboxylic acid, and isooctanoic acid;

   Preferably, the aromatic hydrocarbon-based carboxylic acid is selected from sec-octylphenoxyacetic acid and / or sec-nonylphenoxyacetic acid;

   Preferably, the cyclic alkane-based carboxylic acid is selected from carboxylic acids containing cyclopentyl or cyclohexyl.
9. The preparation method according to claim 7, wherein the concentration of the phase regulator in the organic solution of the extractant is 5 to 25 vol%;

   Preferably, the phase modifier is an alkyl alcohol, preferably one or more of n-butanol, n-hexanol, n-octanol and isooctanol.
10. The method according to claim 7, wherein the concentration of the organic carboxylic acid extractant in the organic solution of the extractant is 0.5-3.5 mol / L.
11. The method according to claim 4, wherein the ratio of the number of moles of the organic carboxylic acid extractant to the number of moles of europium ions in the europium-containing solution is denoted as A, and 3 ≦ A ≦ 20.
12. The preparation method according to claim 4, characterized in that, during the precipitation reaction, a ratio of the amount of fluorine ion to a substance containing thorium element in the thallium-containing organic phase is denoted as B, and 4≤B≤6, The volume ratio of the rhenium-containing organic phase to the fluorine-containing mixed solution is 1:10 to 10: 1.
13. The preparation method according to claim 4, wherein the extraction process is performed under conditions of pH 2 to 4.
14. The preparation method according to any one of claims 4, 6 to 13, wherein the precipitation reaction further comprises: sequentially performing thermal aging, solid-liquid separation, washing and drying treatment on the product system of the precipitation reaction, Obtaining the submicron-level rhenium fluoride;

    Preferably, the temperature of the heat preservation and sedimentation process is 90 to 150 ° C, and the time is 1 to 8 hours;

    Preferably, the temperature of the drying process is 90 to 105 ° C;

    Preferably, in the washing process, the product system of the precipitation reaction is washed with ethanol and / or water.
15. The preparation method according to any one of claims 5 to 13, wherein the precipitation reaction further comprises:

    The product system of the precipitation reaction is sequentially subjected to thermal aging, solid-liquid separation, washing and drying to obtain ammonium fluoride 钪 double salt precipitation;

    Subjecting the ammonium fluoride rhenium double salt precipitate to successive washing and dehydration and deamination treatment to obtain the micron-level rhenium fluoride;

    Preferably, the temperature of the heat preservation and sedimentation process is 80 to 120 ° C, and the time is 1 to 4 hours;

    Preferably, the temperature of the drying process is 90 to 105 ° C;

    Preferably, the temperature of the dehydration and deamination treatment process is 300 to 400 ° C, and the time is 2 to 4 hours;

    Preferably, in the washing process, the ammonium fluoride rhenium double salt precipitate is washed with ethanol and / or water.
16. The preparation method according to claim 2, wherein in the S3, the ratio of the amount of F ^- ions in the HF and / or NaF solution to the amount of rhenium in the rhenium-containing inorganic acid solution is greater than 3 and less than 4.5.
17. The method according to claim 2, wherein the acidic organic phosphorus extractant is selected from the group consisting of bis (2-ethylhexyl) phosphoric acid, 2-ethylhexyl phosphate mono-2-ethylhexyl phosphate, and Cyanex272 One or more of the group consisting of agents.
18. The preparation method according to claim 2, wherein the organic extractant in the organic solvent solution containing the acidic organic phosphorus extractant is at least one of alkanes or mixtures thereof or aromatic hydrocarbons having a density less than water. One kind

    Preferably, the alkane or a mixture thereof includes n-heptane, n-hexane and kerosene;

    Preferably, the aromatic hydrocarbons include benzene and toluene.
19. The method according to claim 17 or 18, wherein the concentration of the acidic organic phosphorus-containing extractant in the organic solvent solution containing the acidic organic phosphorus extractant is 0.01 mol / L to 4 mol / L.
20. The preparation method according to claim 2, wherein the rhenium-containing inorganic acid solution is a rhenium-containing sulfuric acid solution, a hydrochloric acid solution, or a nitric acid solution.
21. The preparation method according to claim 2, wherein a volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the rhenium-containing inorganic acid solution is (1:20) to (1: 1).
22. The method according to claim 16, wherein a volume ratio of the organic solvent solution containing the acidic organic phosphorus extractant to the HF and / or NaF solution in S3 is (1:20) to (20: 1).
23. The production method according to claim 2, characterized in that, the S4 comprising: was washed with ethanol and water the precipitate ScF _3.
24. The preparation method according to claim 23, wherein the temperature for washing with ethanol is 20 to 40 ° C, and the temperature for washing with water is 50 to 90 ° C.
25. The preparation method according to claim 2, wherein in S2, the washing liquid used for the washing treatment is a 0.1 to 2 mol / L hydrochloric acid aqueous solution or a 0.1 to 1 mol / L sulfuric acid aqueous solution.
26. The preparation method according to claim 2, characterized in that: the precipitating mother liquor in S3 is added to HF and / or NaF and then returned to the back extraction treatment step, and the no-load organic phase is returned to S1 to be used in the radon extraction treatment step. .
27. The preparation method according to claim 2, wherein the mixing in the krypton extraction and back extraction processing uses mechanical mixing or ultrasonic mixing to speed up the progress of the reaction.
28. The preparation method according to claim 2, wherein the reaction temperature of the back extraction is 20 to 70 ° C, preferably 25 to 45 ° C.
29. The method according to claim 2, wherein in S1, the acidic organic phosphorus extractant in the organic solvent solution containing the acidic organic phosphorus extractant and the thallium in the thorium-containing inorganic acid solution The ratio of the amounts of substances is greater than 3 and less than 20.
30. The preparation method according to claim 2, wherein the temperature of the rhenium fluoride precipitation in the S4 to dry the rhenium fluoride product is 90-105 ° C.