CN117887986A

CN117887986A - Synergistic extractant for separating samarium and cobalt in solution, preparation method and application thereof

Info

Publication number: CN117887986A
Application number: CN202211223764.8A
Authority: CN
Inventors: 孙晓琦; 张锶佳; 倪帅男; 莫棣棠; 曾志远
Original assignee: Xiamen Institute of Rare Earth Materials; Ganjiang Innovation Academy of CAS
Current assignee: Xiamen Institute of Rare Earth Materials; Ganjiang Innovation Academy of CAS
Priority date: 2022-10-08
Filing date: 2022-10-08
Publication date: 2024-04-16

Abstract

The invention relates to a synergistic extractant for samarium cobalt separation in solution, a preparation method and application thereof, and solves the problems of low extraction rate, poor separation effect, low acid-base consumption of the existing samarium cobalt extraction system, pollution of saponification wastewater and further green need of extractant phosphorus. The extractant consists of primary amine N1923 and saturated fatty acid with carbon chain of C10-C12. The application comprises the steps of extracting and separating samarium and cobalt in a solution by adopting the extractant, and specifically comprises the following steps: and extracting the organic phase containing the samarium and cobalt by adopting an organic phase containing the extractant, and obtaining the samarium-containing material through back extraction. According to the invention, a synergistic extraction system of saturated fatty acid and primary amine N1923 is adopted, so that the samarium and cobalt in the solution are effectively separated, the rare earth and transition metal are separated by a high separation coefficient, and the rare earth and valuable metal in the secondary resource can be effectively recovered.

Description

Synergistic extractant for separating samarium and cobalt in solution, preparation method and application thereof

Technical Field

The invention relates to the field of rare earth extraction separation, in particular to a synergistic extractant for samarium cobalt separation in solution, a preparation method and application thereof.

Background

In recent years, samarium cobalt magnets have been widely used in critical fields due to excellent corrosion resistance and temperature characteristics, and about 30% of the total yield is wasted as magnetic waste during polishing and finishing to obtain a desired size product, and the discharge of such waste may cause environmental pollution, and such waste may be recycled as an important secondary resource of cobalt and samarium. Not only can the cost of critical materials be reduced, but also environmental problems associated with mining and mineral processing can be reduced. Therefore, the recovery of valuable elements from waste samarium cobalt magnets is of interest.

At present, rare earth element separation and purification technologies mainly comprise solvent extraction, ion exchange, precipitation crystallization, membrane separation methods and the like, wherein the solvent extraction has been widely applied in industry due to the advantages of large treatment capacity, good separation selectivity, high mass transfer speed and the like.

As CN108251649a discloses a hydrometallurgical treatment process for recycling samarium cobalt alloy resources, the hydrometallurgical treatment process for recycling samarium cobalt alloy resources comprises the following steps: s1: crushing and ball milling; s2: leaching; s3: removing samarium; s4: iron removal; s5: extracting and removing impurities; s6: recovering heavy metals; s7: preparing cobalt salt; s8: the wastewater treatment adopts the method to leach the samarium cobalt alloy cobalt, the samarium and the iron with leaching rates of 99 percent, 98 percent and 98 percent respectively, the recovery rate of each metal can reach more than 95 percent, and the recovery rate of Cu can reach 98 percent. According to the scheme, the valuable metals in the samarium cobalt alloy are effectively separated and recycled by leaching under the specified acidity and temperature conditions, so that secondary environmental hazard in the recovery process of the samarium cobalt alloy is avoided, comprehensive recovery and utilization of samarium cobalt resources are facilitated, and higher economic benefit and environmental benefit are realized.

CN104928479a discloses a method for treating samarium cobalt alloy, firstly leaching the finely ground samarium cobalt alloy in a sulfuric acid system of 4-6mol/L, and separating cobalt and a small amount of samarium from most of samarium by entering the solution; the samarium in the solution is mixed with most of samarium remained in leaching residue by regulating pH precipitation, and is converted by sodium carbonate, and then is dissolved by hydrochloric acid and precipitated by oxalic acid, and then is directly baked to prepare the samarium oxide product. According to the scheme, the concentration and the temperature of sulfuric acid are controlled, so that the leaching rate of samarium is greatly reduced, the separation of samarium and cobalt is primarily realized, and the subsequent samarium precipitation process is facilitated; the samarium-containing precipitate and the samarium-containing leaching residue are converted by sodium carbonate, so that the inclusion of samarium sulfate and double salts thereof is avoided, and the temperature for preparing samarium oxide by subsequent roasting is reduced; the protection of the nitrogen atmosphere can inhibit the oxidation of cobalt in the reaction process, thereby ensuring that more than 99.5 percent of cobalt in the alloy cannot be oxidized and hydrolyzed into samarium-containing precipitates.

However, the extraction system utilized in the existing extraction technology for samarium and cobalt generally only contains one extractant and a trace amount of modifier, and the treated metal ion solution is relatively single, so that the separation effect is required to be improved. In addition, the acid-base consumption of the existing samarium cobalt extraction system needs to be reduced, the saponification wastewater is polluted, and the extractant phosphorus needs to be further green.

Disclosure of Invention

In view of the problems in the prior art, the invention aims to provide a synergistic extractant for separating samarium and cobalt in solution, and a preparation method and application thereof, and solves the problems of low extraction rate and poor separation effect existing in the prior art for extracting and separating samarium and cobalt.

To achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides an extractant for extracting samarium in solution, the extractant consisting of a primary amine N1923 and saturated fatty acids with carbon chains of C10-C12.

The extracting agent provided by the invention adopts a synergistic extraction system of saturated fatty acid and primary amine N1923, so that the effective separation of samarium and cobalt in the solution is realized, the synergistic extraction system has higher synergistic factor on the extraction of rare earth as the extracting agent, has higher separation coefficient on the rare earth and transition metal, can effectively recover the rare earth and valuable metal in secondary resources, and has better recycling performance.

In the present invention, synergistic extraction means that when two or more extractant systems are used simultaneously to extract metal ions under the same conditions, the partition ratio is larger than the sum of the partition ratios of the metal ions extracted individually (D _Synergism >D _{Adding up} ) I.e. the mixing system has a synergistic effect. Conversely, when the partition ratio of the combined extractant system to metal ions is smaller than the sum of the partition ratios of the individual extractant-extracted metal ions (D _Synergism <D _{Adding up} ) These two or more extractant systems do not have a synergistic effect, i.e. a countersynergistic effect. The synergistic extraction system can not only increase the extraction and selectivity of metal ions, but also improve the dissolving capacity of the extractant in the organic phase, eliminate emulsification and reduce the generation of a third phase. Is generally considered as D _Synergism >D _{Adding up} The main reason is that the more stable complex is generated in the synergistic extraction system, and the oil solubility of the complex is increased, so that the extraction rate can be remarkably increased. The synergic extraction technology can process a complex metal solution system to realize multi-metal separation.

In the invention, the structural formula of the primary amine N1923 is shown as the formula (1):

wherein R is ₁ And R is ₂ And C9-C11 linear carbon chains, respectively.

In a preferred embodiment of the present invention, the primary amine N1923 in the extractant is 20 to 80% by mole, for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78% or 80%, etc., but not limited to the recited values, and other non-recited values in this range are equally applicable, preferably 40 to 60%.

As a preferred embodiment of the present invention, the saturated fatty acids in the extractant include lauric acid and/or capric acid. Namely, the saturated fatty acid with the carbon chain of C10-C12 can be lauric acid and/or capric acid, and the like, when myristic acid, palmitic acid or stearic acid with longer carbon chains and N1923 are adopted for compound extraction, obvious emulsification phenomenon appears, and the extraction rate is obviously lower than that of the saturated fatty acid with the carbon chain of C10-C12.

In a second aspect, the invention provides a method for preparing the extractant according to the first aspect, wherein the method comprises mixing primary amine N1923 and saturated fatty acid with carbon chain of C10-C12 according to a formula.

In a third aspect, the present invention provides a use of the extractant of the first aspect, the use comprising the extraction separation of samarium and cobalt in solution using the extractant, comprising in particular: and extracting the organic phase containing the samarium and cobalt by adopting an organic phase containing the extractant, and obtaining the samarium-containing material through back extraction.

As a preferred embodiment of the present invention, the organic phase containing the extractant is added with a phase modifier and a diluent.

As a preferred embodiment of the present invention, the phase modifier comprises 1 or a combination of at least 2 of isooctanol, ethylene glycol, TBP, or glycerol, preferably isooctanol;

the combination may be a combination of isooctyl alcohol and ethylene glycol, a combination of ethylene glycol and TBP, a combination of TBP and glycerol, or the like.

Preferably, the volume ratio of the extractant to the phase modifier is (1-50): 50-99, which may be, for example, 1:99, 1:80, 1:70, 1:60, 1:50, 1:1, 50:60, 50:70, 50:80, 50:90 or 50:99, etc., preferably (2-40): 60-98).

As a preferred embodiment of the present invention, the diluent comprises an alkane and/or an arene.

In the present invention, the alkane may be 1 or at least 2 of heptane, octane, hexadecane, aviation kerosene or 260# solvent kerosene, and the combination may be a combination of heptane and octane, a combination of octane and hexadecane, a combination of hexadecane and aviation kerosene, a combination of aviation kerosene and 260# solvent kerosene, or the like.

In the present invention, the aromatic hydrocarbon may be 1 or at least 2 of benzene, toluene or xylene, and the combination may be a combination of benzene and toluene, a combination of toluene and xylene, a combination of benzene and xylene, or the like.

Preferably, the volume ratio of extractant to diluent is (1-50): 50-99, which may be, for example, 1:99, 1:80, 1:70, 1:60, 1:50, 1:1, 50:60, 50:70, 50:80, 50:90 or 50:99, etc., preferably (2-40): 60-98).

As a preferred embodiment of the present invention, the pH of the samarium and cobalt-containing solution is 1 to 5, for example, 1, 2, 3, 4 or 5, etc., but not limited to the values recited, and other values not recited in the range are equally applicable.

In the present invention, the influence of the initial pH of the aqueous solution plays a critical role in metal extraction. During the extraction process, H ⁺ And RE (RE) ³⁺ Competition in aqueous solutions is intense, especially under strongly acidic conditions. Wherein the extraction system has the best extraction effect on samarium (III) at the pH value of 3-5 aiming at the extractant. Within this pH range, H can be minimized ⁺ Thereby achieving an efficient separation of samarium (III) and cobalt (II).

Preferably, a salting-out agent is added to the samarium and cobalt containing solution.

In the invention, the salting-out agent can be added according to actual conditions, and the extractant provided by the invention can have good extraction and separation effects when the salting-out agent is not added, and can further improve the extraction and separation effects after the salting-out agent is introduced.

In the present invention, the salting-out agent may be a chloride salt, for example, may be a combination of 1 or at least 2 of sodium chloride, ammonium chloride and potassium chloride, and the combination may be a combination of sodium chloride and ammonium chloride, a combination of ammonium chloride and potassium chloride, a combination of potassium chloride and sodium chloride, or the like.

Preferably, the molar concentration of the salting-out agent in the samarium and cobalt-containing solution is 0.01 to 1.0mol/L, for example, 0.01mol/L, 0.02mol/L, 0.03mol/L, 0.04mol/L, 0.05mol/L, 0.06mol/L, 0.07mol/L, 0.08mol/L, 0.09mol/L, 0.1mol/L, 0.2mol/L, 0.3mol/L, 0.4mol/L, 0.5mol/L, 0.6mol/L, 0.7mol/L, 0.8mol/L, 0.9mol/L, or 1mol/L, etc., but other non-enumerated values within this range are equally applicable, preferably 0.05 to 0.8mol/L, more preferably 0.3 to 0.7mol/L.

As a preferred embodiment of the present invention, the use comprises: extracting the organic phase containing samarium and cobalt by adopting an organic phase containing the extractant, and obtaining a samarium-containing material through back extraction;

the organic phase containing the extractant is added with a phase modifier and a diluent; the phase modifier comprises 1 or a combination of at least 2 of isooctyl alcohol, ethylene glycol, TBP or glycerol; the volume ratio of the extractant to the phase modifier is (1-50) (50-99); the diluent comprises alkane and/or arene; the volume ratio of the extractant to the diluent is (1-50) (50-99);

the pH value of the solution containing samarium and cobalt is 1-5; a salting-out agent is added into the solution containing samarium and cobalt; the molar concentration of the salting-out agent in the solution containing samarium and cobalt is 0.01-1.0mol/L.

In the present invention, the agent used in the back extraction may be a combination of 1 or at least 2 of an inorganic acid, oxalic acid or oxalic acid, and the inorganic acid may be a combination of 1 or at least 2 of hydrochloric acid, nitric acid and sulfuric acid.

In the invention, the oxalate can be ammonium oxalate, sodium oxalate and potassium oxalate. Other soluble inorganic salts are also possible, such as sodium carbonate and the like.

In the invention, the concentration of the reagent in the back extraction can be obtained through the back extraction experiment verification with a certain gradient, and the invention is not particularly limited. For example, the concentration of sodium oxalate may be between 0.01 and 1.0mol/L.

In the invention, the solution containing samarium and cobalt can be a solution obtained by leaching SmCo magnet to remove impurities, or a solution obtained by leaching natural minerals to remove impurities or a solution containing samarium and cobalt obtained by other methods in the field.

In the invention, the samarium-containing material obtained by back extraction is different according to the selection of the back extraction reagent, for example, when the back extraction is carried out by adopting oxalate solution or oxalic acid solution, the samarium-containing precipitate is obtained by back extraction, for example, when the back extraction is carried out by adopting inorganic acid (nitric acid, hydrochloric acid and sulfuric acid), the samarium-containing solution is obtained. However, when acid liquor is used as a stripping agent, the stripped organic phase is acidified, so that the extraction and separation effect of the extractant is weakened and effective recycling cannot be performed, therefore, the oxalate solution is preferably used as the stripping agent for stripping, the influence on the organic phase after stripping is small, and the stripping agent has good recycling performance.

Compared with the prior art, the invention has the following beneficial effects:

according to the compound extractant provided by the invention, the hydrogen bond between saturated fatty acid molecules is weakened through the hydrogen bond formed between primary amine N1923 and saturated fatty acid, so that the extractant provided by the invention realizes further improvement of extraction performance under the condition that saturated fatty acid hydrogen ions are not removed.

Drawings

FIG. 1 is a distribution ratio chart of the gradient extraction of the extractant in example 1;

FIG. 2 is a graph of the synergistic coefficient of gradient extraction of the extractant in example 1;

FIG. 3 is a graph showing the extraction rate of the gradient extraction of the extractant in example 1;

FIG. 4 is a schematic diagram of the extraction mechanism of the extractant in example 1;

FIG. 5 is a graph showing comparison of extraction effects of different extraction systems in example 1;

FIG. 6 is a graph of the extraction effect of fully saponified lauric acid on samarium and cobalt containing solutions of example 1;

FIG. 7 is a graph showing the comparison of the effect of different organic acids in the extraction system of example 1;

FIG. 8 is a graph showing the back extraction result of sodium oxalate in example 1;

FIG. 9 is a graph of the results of the multistage extraction-stripping in example 1.

In the figure, E is the extraction rate, D is the partition ratio, R is the synergistic coefficient, and S is the stripping rate.

The present invention will be described in further detail below. The following examples are merely illustrative of the present invention and are not intended to represent or limit the scope of the invention as defined in the claims.

Detailed Description

For a better illustration of the present invention, which is convenient for understanding the technical solution of the present invention, exemplary but non-limiting examples of the present invention are as follows:

examples1

The embodiment provides an extraction separation method for separating samarium and cobalt in a solution, which comprises the following steps:

sulfonated kerosene (# 260) was used as a diluent. And respectively weighing extractant with certain mass, and then adding isooctanol and sulfonated kerosene with certain proportion to prepare an organic phase required by an extraction experiment. The two extractants used for the synergistic extraction were mixed uniformly by shaking with a mechanical thermostatted shaker at room temperature (25 ℃) for 15min at a rotational speed of 300 r/min.

In many extraction systems, the addition of the phase modifier can effectively avoid the occurrence of poor extraction phenomena such as emulsification or third phase, and can allow the extraction reaction to reach equilibrium more quickly. In order to explore whether the addition of the phase modifier has an influence on the extraction effect of the N1923+ lauric acid synergistic extraction system, the initial experiment selects isooctyl alcohol as the phase modifier, and the extraction results of isooctyl alcohol with different volume ratios are compared. Experiments show that the experimental group without isooctyl alcohol is emulsified in extraction, and the emulsification phenomenon can be avoided by adding isooctyl alcohol with a certain proportion. After comprehensive consideration, the volume ratio of isooctanol to be added in this example was 10%.

In the extraction experiments, equal volumes of the organic and aqueous phases (unless otherwise noted) were mixed in a centrifuge tube and shaken at 300r/min for 40min using a mechanical thermostatted shaker at room temperature (25 ℃) (preliminary experiments indicated an extraction equilibration time of less than 10 min). After the extraction equilibrium, the organic and aqueous phases were centrifuged at 3000r/min for 4min to effect phase separation.

In the stripping experiments, the samarium-loaded organic phase and the stripping agent (Na ₂ C ₂ O ₄ Aqueous solution) was mixed in a centrifuge tube and shaken at 300r/min for 30min using a mechanical thermostatted shaker at room temperature (25 ℃). The organic and aqueous phases were then separated by centrifugation at 3000r/min for 4min using a centrifuge. After back extraction, the organic phase is washed with deionized water and then reused.

The concentration of metal ions in the aqueous phase was measured by inductively coupled plasma-atomic emission spectrometry (ICP-OES), and the concentration of metal ions in the organic phase was calculated by mass conservation. The extraction rate (E), partition rate (D), synergy coefficient (R), separation coefficient (β), and stripping rate (S) are defined as the following formulas (2) to (6):

in the above, [ M ]] _aq And [ M ]] _ra Indicating the initial and equilibrium concentration of the extracted metal in the aqueous phase. D (D) _a Is the distribution ratio of the extractant to the extracted metal; d (D) _b Is the distribution ratio of the other extractant to the extracted metal; d (D) _mix Is a mixed extraction system for gold to be extractedBelonging to the distribution ratio. D (D) ₁ And D ₂ The partition ratio of the extracted metals 1 and 2 respectively. [ M ]] _org,i Is the initial concentration of the extracted metal in the extract phase, [ M ]] _aq,s Is the equilibrium concentration of the extracted metal in the water phase after back extraction. All extracted metal concentration values are in triplicate, and the measurement uncertainty is within 5%.

On the basis, the invention further verifies the extraction system, and three experiments are carried out:

A. performing gradient extraction experiments on the samarium and cobalt-containing solution by adopting N1923 with the molar concentration of less than or equal to 0.3 mol/L;

B. performing gradient extraction experiments on samarium-and cobalt-containing solution by using lauric acid with the molar concentration of less than or equal to 0.3 mol/L;

C. performing gradient extraction experiments on the samarium and cobalt-containing solution by adopting mixed solution of N1923 +lauric acid with the total molar concentration of 0.3 mol/L;

in the extraction process, the index parameters of the samarium and cobalt-containing solution are as follows: c (samarium (III))=c (cobalt (II))=0.01 mol/L, c (NaCl) =0.4 mol/L, ph=4.0; the extraction process control parameters are as follows: v% (isooctanol) =10% in the organic phase, t=30 ℃ compared to O/a=1. The extraction results are shown in fig. 1, 2 and 3, and it can be seen from fig. 1, 2 and 3 that the extraction rates E of samarium (III) and cobalt (II) generally increase with the increase of the total concentration of lauric acid and N1923. When the synergistic coefficient R of the mixed extraction system of the N1923 and the lauric acid on the samarium (III) reaches 61.94, the separation coefficient beta of the samarium and the cobalt in the extraction system is about 5326, so that the effective separation of the samarium and the cobalt is ensured, namely, the system has good separation effect on the samarium/cobalt, and a larger separation factor can be obtained. The synergistic coefficient R of the synergistic extraction system in this embodiment is 61.94, the separation factor is 5326, which is higher than that of the rare earth synergistic extraction system in the prior art, because the hydrogen bond between the acidic extractants affects the extraction and separation capability thereof, and in general, the saponification method eliminates the hydrogen ions on the functional groups of the extractants through acid-base neutralization reaction, breaks the hydrogen bond between the extractants, and improves the extraction and separation capability of the acidic extractants.

Further, the present embodiment also compares the extraction effects of the extractant related to the present invention on the solution containing samarium and cobalt under different conditions, and the results are shown in fig. 5 and 6, in fig. 5, a corresponds to the extraction process of the acidified N1923 on the solution, b corresponds to the extraction process of the lauric acid and the acidified N1923 to form the extractant, c corresponds to the extraction process of the acidified N1923 and 100% saponified lauric acid to form the extractant, d corresponds to the extraction process of the N1923+lauric acid to form the extractant in the present invention, and as can be seen from the figure, the extraction effects of the acidified N1923 on the samarium and cobalt are both poor, and the acidification of the N1923 in the combined extractant also significantly affects the final extraction separation effect, so that the extraction rate of cobalt is significantly improved, so that the separation effect is deteriorated, as can be seen from fig. 6, the saponified lauric acid is severely emulsified in the extraction process, the extraction of samarium (III)/cobalt (II) is not selective, and the effect of the N1923+lauric acid system is good in the extraction process, and samarium (III)/cobalt (II) can be effectively separated. (during extraction, c (samarium (III))=c (cobalt (II))=0.01 mol/L, c (lauric acid)/c (N1923) is 1:1, c (NaCl) =0.4 mol/L, ph=4.0, and the amounts of extractant used for the individual extractant and the combined extractant in comparison are the same as for O/a=1, v% (isooctyl alcohol) =10%, t=30 ℃).

Further, comparison and verification are also carried out on organic acids in an N1923+lauric acid system, wherein the organic acids comprise capric acid, lauric acid, myristic acid, palmitic acid and stearic acid, and in the extraction process, the index parameters of samarium-cobalt-containing solution are as follows: c (samarium (III))=c (cobalt (II))=0.01 mol/L, c (NaCl) =0.4 mol/L, ph=4.0; the extraction process control parameters are as follows: v% (isooctanol) =10% in the organic phase, t=30 ℃ compared to O/a=1; as shown in FIG. 7, when the organic acid is compounded with saturated fatty acid with carbon atom more than 12, such as myristic acid, palmitic acid or stearic acid, the resulting extractant is obviously emulsified, and the extraction separation performance of the extractant is reduced, namely, the C10-C12 saturated fatty acid is specifically selected to achieve good extraction effect with N1923.

In the field, the back extraction of the extracted organic phase has obvious influence on the recovery of elements, and the back extraction has important significance for the recovery of metal ions and the recycling of the extractant. In this example, sodium oxalate was also studied as a stripping agent, and the results are shown in fig. 8, which show that the stripping rate S of 0.20mol/L sodium oxalate to samarium (III) can reach 96.7%, and that water also has a certain stripping effect on samarium (III) in the loaded organic phase, i.e., the loaded organic phase can be completely stripped from samarium (III) in the loaded organic phase by water washing after stripping with sodium oxalate.

Further, a multistage cyclic extraction-back extraction experiment (c (sodium oxalate) =0.20 mol/L, c (samarium (III))=c (cobalt (II))=0.01 mol/L, c (lauric acid) =c (N1923) =0.15 mol/L, c (NaCl) =0.4 mol/L, ph=4.0, and as a result, see in detail fig. 9, N1923+ lauric acid synergistic extraction system maintains good stability after regeneration with sodium oxalate and circulation 5 times, compared to O/a=1, v% (isooctanol) =10%, t=30 ℃); and (3) after back extraction of the loaded organic phase by sodium oxalate, washing the obtained samarium-containing material for 3 times by using an ammonia water solution with the volume fraction of 4%, and roasting in a muffle furnace at 800 ℃ to obtain the samarium sesquioxide with higher purity. The purity of the cobalt solution consisting of the raffinate and the washing liquid is 99.5%, and the recovery rate of cobalt is more than 99%. The synergistic extraction system of N1923 and lauric acid keeps higher extraction rate E > 97% for samarium (III) in 5 cycles, and the extraction rate E for cobalt (II) is always lower than 3%, which shows that the developed system is effective and sustainable for separating samarium and cobalt in a hydrochloric acid system.

In the experimental process, the samarium and cobalt solution is prepared.

Examples2

Application of synergistic extraction system in actual samarium cobalt magnet recovery:

and (3) separating the selectivity performance of the samarium/cobalt in the actual samarium cobalt magnet by using a synergistic system of N1923 and lauric acid, and firstly roasting the crushed samarium cobalt magnet in a muffle furnace at 850 ℃ for 6 hours to demagnetize. Multiple purifications were performed before extraction separation of samarium (III) and cobalt (II);

the method specifically comprises the following steps: under heating, analytically pure concentrated hydrochloric acid and 30% by mass of H are used ₂ O ₂ The demagnetized samarium cobalt magnet is leached. After cooling, the leachate is filtered to remove insoluble zirconium metal. Copper (II) in the leachate was removed using an N902 extraction system. Copper (II) in the leaching solution is extracted by using a 25% N902-10% isooctyl alcohol-65% kerosene system, and the extraction rate of copper (II) reaches 98%. The organic phase loaded with copper (II) can be prepared with 4mol/L H ₂ SO ₄ Back extraction to obtain CuSO ₄ Can be recycled. The iron (III) in the percolate is removed by precipitation. The pH of the copper-depleted raffinate was adjusted to 4.0 by adding NaOH solution to precipitate iron (III) into Fe (OH) ₃ . At this stage, the removal rate of iron (III) in the leachate can reach 99%.

And (3) recovering samarium (III) and cobalt (II) in the percolate from the iron-removed extract by using a N1923+lauric acid synergistic extraction system. Lauric acid and N1923 extractant are mixed in equimolar ratio. The extraction conditions were ph=4.0 for the initial solution and 30 ℃.

In the above experimental procedure, the content of metal ions in the aqueous phase was determined by inductively coupled plasma emission spectrometry.

Table 1 summarizes the metal ion content in the feed solution after each separation stage.

TABLE 1

a 20mL of leaching solution after insoluble zirconium metal is removed.

b 20mL of copper-depleted solution. The specific conditions for extraction are: 25% N902-10% isooctanol-65% kerosene system (volume fraction), pH=1.93, T=30℃, compared to O/A=1.

c 20mL of the iron-removed solution. The pH value of the solution is regulated to about 4.0, and all Fe is filtered off ³⁺ And (5) precipitation.

The d N1923+lauric acid system is used for synergistic extraction. c (lauric acid) =c (N1923) =0.225 mol/L, ph=4.0, no salting-out agent was added, v% (isooctanol) =10% in the organic phase, t=30 ℃ compared to O/a=1.

As can be seen from Table 1 and by simple calculation, the recovery rates of samarium (III) and cobalt (II) in the whole recovery process were 90.53% and 93.19%, respectively. When the extraction rate of samarium (III) is 97.2%, the extraction rate of cobalt (II) is only 0.2%, and the separation coefficient of samarium (III) and cobalt (II) can reach 16222. The N1923 and lauric acid synergistic extraction system has higher separation performance and shows good application potential in samarium cobalt magnet separation.

It is stated that the detailed structural features of the present invention are described by the above embodiments, but the present invention is not limited to the above detailed structural features, i.e., it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. An extractant for extracting samarium in solution, characterized in that the extractant consists of primary amine N1923 and saturated fatty acid with carbon chain of C10-C12.

2. Extractant according to claim 1, wherein the primary amine N1923 in the extractant is 20-80%, preferably 40-60% in mole percent.

3. Extractant according to claim 1 or 2, wherein the saturated fatty acids in the extractant comprise lauric acid and/or capric acid.

4. A process for the preparation of an extractant according to any one of claims 1 to 3, which comprises mixing primary amine N1923 with a saturated fatty acid having a carbon chain of C10 to C12 according to a formula.

5. A use of the extractant according to any one of claims 1 to 3, comprising the extractive separation of samarium and cobalt in solution using the extractant, comprising in particular: and extracting the organic phase containing the samarium and cobalt by adopting an organic phase containing the extractant, and obtaining the samarium-containing material through back extraction.

6. The use of an extractant according to claim 5, wherein a phase modifier and a diluent are added to the extractant-containing organic phase.

7. The use of an extractant according to claim 6 wherein the phase modifier comprises 1 or a combination of at least 2 of isooctanol, ethylene glycol, TBP, or glycerol;

preferably, the volume ratio of the extractant to the phase modifier is (1-50): 50-99, preferably (2-40): 60-98.

8. Use of an extractant according to claim 6 or 7, wherein the diluent comprises an alkane and/or an aromatic hydrocarbon;

preferably, the volume ratio of extractant to diluent is (1-50): 50-99, preferably (2-40): 60-98.

9. The use of an extractant according to any one of claims 5 to 8 wherein the pH of the samarium and cobalt containing solution is from 1 to 5;

preferably, a salting-out agent is added to the solution containing samarium and cobalt;

preferably, the molar concentration of salting-out agent in the samarium and cobalt containing solution is 0.01-1.0mol/L, preferably 0.05-0.8mol/L, more preferably 0.3-0.7mol/L.

10. The use according to any one of claims 5-9, wherein the use comprises: extracting the organic phase containing samarium and cobalt by adopting an organic phase containing the extractant, and obtaining a samarium-containing material through back extraction;