Preparation method of zirconium and hafnium complex supramolecular network and its application

Abstract

The present invention discloses a method for preparing a supramolecular network of zirconium and hafnium complexes and its application, belonging to the technical field of zirconium and hafnium separation. The present invention forms a planar quadrilateral compound by forming a coordination bond or ionic association between zirconium or hafnium and a coordination ion or neutral ligand, and utilizes the planar quadrilateral compound and a neutral compound containing a π bond or a delocalized π bond to form a supramolecular network through p-π stacking and π-π stacking. Based on the fact that the planar quadrilateral compound of zirconium and hafnium has different stability in the supramolecular network depending on the process conditions, the separation of zirconium and hafnium is achieved. Compared with traditional methods, the present method does not require the use of an extraction system using a mixed acid or mixed extractant, thereby solving the problems of environmental pollution caused by the discharge of large amounts of waste acid and alkali, as well as the flammability and explosiveness of the extractant.

Description

Technical Field

[0001] The present invention relates to the technical field of zirconium and hafnium separation, in particular to a preparation method of a zirconium and hafnium complex supramolecular network and application thereof. Background Art

[0002] Zr and Hf coexist in an isomorphous manner in nature; there are no separate zirconium or hafnium ores. The mass content of Hf in Zr chemicals is approximately 1-3% of Zr. Practical applications require high-purity zirconium or hafnium products, necessitating suitable separation methods to separate and purify the zirconium and hafnium mixtures. Due to the lanthanide contraction, the physicochemical properties of zirconium and hafnium are similar, making their separation difficult. Industrial methods for separating Zr and Hf include fractional crystallization, molten salt distillation, ion exchange, and solvent extraction. Solvent extraction, with its advantages of high throughput, low cost, and ease of continuous production, has become the most important method for separating Zr and Hf. Widely used extraction separation processes include: the MIBK-NH4SCN method, where the organic phase consists of MIBK and the aqueous phase contains NH4SCN; the TBP-HNO3-HCl method, where the extractant is TBP and the aqueous medium is a mixed acid medium of HNO3-HCl; and the TOA / N235-H2SO4 method, where the extractant is a tertiary amine and the aqueous phase is a sulfate. These solvent extraction separation methods generally extract all or part of the zirconium and hafnium in the mixed solution into the organic phase, followed by washing and back-extraction to obtain the zirconium and hafnium products, respectively.

[0003] Existing methods for separating zirconium and hafnium primarily utilize commonly used acidic phosphonic acid extractants, neutral phosphine oxide and ketone extractants, and alkaline amine extractants. These extraction systems often suffer from slow phase separation, low separation coefficients, severe environmental pollution from added coordinating ions, and difficulty in handling. Some extractants also have low boiling points and are flammable and explosive.

[0004] Based on this, a method for separating zirconium and hafnium by using supramolecular networks of zirconium and hafnium complexes was proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a supramolecular network of zirconium and hafnium complexes and its application, so as to solve the problems in the background technology.

[0006] To achieve the above object, the present invention provides a method for preparing a supramolecular network of zirconium and hafnium complexes, comprising the following steps:

[0007] The temperature and acidity of the reaction system are determined, and a certain concentration of zirconium and hafnium salt solution is added to a hydrochloric acid medium. Then, a compound containing a coordination ion or a neutral ligand is added to react to obtain a planar quadrilateral compound; then, a neutral compound is added to the reaction to obtain a supramolecular network.

[0008] Preferably, the reaction system temperature is 10-90° C., the acidity is 0-10 mol / L, the concentrations of zirconium and hafnium are both 0.01-3.0 mol / L, and the ratio of zirconium to hafnium is 80-99:20-1.

[0009] Preferably, the coordination ion is a halogen ion or a pseudohalogen ion, specifically F - 、Cl - Br - , I - 、CN - 、OCN - 、SCN _ 、I3 _ .

[0010] Preferably, the neutral ligand is a hydrophobic organic ligand containing negatively charged oxygen, sulfur or phosphorus atoms; the hydrophobic organic ligand is a monodentate, bidentate or polydentate ligand, and the hydrophobic organic ligand contains one or more π bonds or delocalized π bonds.

[0011] Preferably, the neutral ligand is a sulfoxide, an alkyl-substituted thiourea or a thiophosphoric triamide;

[0012] The chemical formula of sulfoxide is R1-S=O-R2, where R1 and R2 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20;

[0013] The chemical formula of the alkyl-substituted thiourea is R1R2NCSNR3R4, wherein R1, R2, R3, and R4 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20;

[0014] The chemical formula of thiophosphoric triamide is PSN3R1R2R3R4R5R6, wherein R1, R2, R3, R4, R5, and R6 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20.

[0015] Preferably, the neutral compound contains a π bond or a delocalized π bond, and the number of carbon atoms in the neutral compound is 6 to 20.

[0016] Preferably, the neutral compound is one of benzene, alkyl-substituted benzene, biphenyl, olefin or conjugated olefin compounds.

[0017] The present invention also provides a supramolecular network of zirconium and hafnium complexes, which is prepared by the above preparation method.

[0018] The present invention also provides an application of a supramolecular network of zirconium and hafnium complexes, and the prepared supramolecular network is applied to the separation of zirconium and hafnium.

[0019] Preferably, the prepared supramolecular network is placed in an aqueous phase, and the aqueous phase is repeatedly contacted with the supramolecular network by changing the acidity of the aqueous phase, thereby finally achieving separation of zirconium and hafnium.

[0020] Therefore, the present invention provides a method for preparing a supramolecular network of zirconium and hafnium complexes and its application. Zirconium or hafnium forms a planar quadrilateral compound with a coordinating ion or neutral ligand in the form of a coordination bond or ionic association, and then utilizes the planar quadrilateral compound and a neutral compound containing a π bond or a delocalized π bond to form a supramolecular network through p-π stacking and π-π stacking. Based on the fact that the planar quadrilateral compound of zirconium and hafnium in the supramolecular network has different stability depending on the process conditions, the separation of zirconium and hafnium is achieved. Compared with traditional methods, this method does not require the use of a mixed acid or mixed extractant extraction system, thus solving the environmental pollution caused by the discharge of large amounts of waste acid and alkali, as well as the flammability and explosiveness of the extractant.

[0021] The technical solution of the present invention is further described in detail below through examples. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further illustrated by the following examples.

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0024] Example 1

[0025] At a system temperature of 30°C and an acidity of 3.0 mol / L, solutions with zirconium and hafnium concentrations of 28.50 g / L and 0.74 g / L, respectively, were added to a hydrochloric acid medium; then 3.0 mol / L of sodium chloride was added (the ionic ligands of zirconium and hafnium were chloride ions). After a period of reaction, 1,3-dodecadiene was added to form a supramolecular network.

[0026] Then, the acidity of the aqueous phase was changed to 2.8 mol / L, and the reaction was repeated several times and contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.0% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 92%.

[0027] Example 2

[0028] At a system temperature of 30°C and an acidity of 3.0 mol / L, solutions with zirconium and hafnium concentrations of 28.50 g / L and 0.74 g / L, respectively, were added to a hydrochloric acid medium; then bis(2-ethylhexyl) sulfoxide was added. After a period of reaction, 1,3-dodecadiene was added to form a supramolecular network.

[0029] Then, the acidity of the aqueous phase was changed to 2.8 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.0% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 92%.

[0030] Example 3

[0031] At a system temperature of 40°C and an acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%), respectively, were added to a hydrochloric acid medium, followed by the addition of 2.5 mol / L of sodium bromide; the ionic ligands of zirconium and hafnium were chloride and bromide ions. After a reaction period, mesitylene was added to form a supramolecular network.

[0032] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.5% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 96%.

[0033] Example 4

[0034] At a system temperature of 40°C and an acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%), respectively, were added to a hydrochloric acid medium, followed by N,N,N,N-tetraoctylthiourea. After a reaction period, mesitylene was added to form a supramolecular network.

[0035] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.5% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 96%.

[0036] Example 5

[0037] At a system temperature of 50°C and an acidity of 4.2 mol / L, a solution containing 22.80 g / L zirconium and 0.59 g / L hafnium (2.6%) was added to a hydrochloric acid medium, followed by 2.0 mol / L sodium thiocyanate. The ionic ligands of zirconium and hafnium were chlorine and thiocyanate ions. After a reaction period, a mixture of mesitylene and 1,3-dodecadiene was added to form a supramolecular network.

[0038] Then, the acidity of the aqueous phase was changed to 3.6 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.9% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 98%.

[0039] Example 6

[0040] At a system temperature of 50°C and an acidity of 4.2 mol / L, a solution containing zirconium and hafnium concentrations of 22.80 g / L and 0.59 g / L (2.6%) was added to a hydrochloric acid medium, followed by the addition of hexa-n-butylthiophosphoric triamide. After a period of reaction, a mixture of mesitylene and 1,3-dodecadiene was added to form a supramolecular network.

[0041] Then, the acidity of the aqueous phase was changed to 3.6 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.9% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 98%.

[0042] Example 7

[0043] At a system temperature of 40°C and an acidity of 3.5 mol / L, a solution with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%), respectively, was placed in a hydrochloric acid medium, followed by the addition of 2.5 mol / L of sodium bromide. The ionic ligands of zirconium and hafnium were chloride and bromide ions. After a period of reaction, a mixture of mesitylene and 1,3-dodecadiene was added to form a supramolecular network.

[0044] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.95% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 99%.

[0045] Example 8

[0046] At a system temperature of 40°C and an acidity of 3.5 mol / L, a solution with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%), respectively, was placed in a hydrochloric acid medium, followed by the addition of hexa-n-butylthiophosphoric triamide; after a period of reaction, a mixture of mesitylene and 1,3-dodecadiene was added to form a supramolecular network.

[0047] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the solution was repeatedly contacted with the supramolecular network to obtain a zirconium solution with a zirconium / (zirconium + hafnium) ratio of 99.95% and a hafnium solution with a hafnium / (zirconium + hafnium) ratio of 99%.

[0048] It can be concluded from Examples 1-8 above that the separation of zirconium and hafnium can be achieved by forming a supramolecular network of zirconium and hafnium and changing the acidity of the aqueous phase in contact with the supramolecular network to change its stability.

[0049] Therefore, the present invention provides a method for preparing a supramolecular network of zirconium and hafnium complexes and its application. Zirconium or hafnium is combined with a coordinating ion or neutral ligand to form a planar quadrilateral compound in the form of a coordination bond or ionic association. The planar quadrilateral compound and a neutral compound containing a π bond or a delocalized π bond are then combined to form a supramolecular network through p-π stacking and π-π stacking. Based on the fact that the zirconium and hafnium planar quadrilateral compounds in the supramolecular network have varying stability depending on the process conditions, the separation of zirconium and hafnium is achieved. Compared with traditional methods, this method does not require the use of a mixed acid or mixed extractant extraction system, thus solving the environmental pollution problems of large amounts of waste acid and alkali discharged and the flammability and explosiveness of the extractant.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a supramolecular network of zirconium and hafnium complexes, characterized in that: Here are the steps: The temperature and acidity of the reaction system are determined, and a certain concentration of zirconium and hafnium salt solution is added to a hydrochloric acid medium. A compound containing a coordination ion or a neutral ligand is then added to react to obtain a planar quadrilateral compound. A neutral compound is then added to the reaction to obtain a supramolecular network. The coordination ion is a halogen ion or a pseudohalogen ion; the neutral ligand is a hydrophobic organic ligand containing negatively charged oxygen, sulfur or phosphorus atoms; the hydrophobic organic ligand is a monodentate, bidentate or multidentate ligand, and the hydrophobic organic ligand contains one or more Bond or delocalization bond; the neutral compound contains Bond or delocalization bond, the number of carbon atoms in a neutral compound is 6 to 20.

2. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 1, characterized in that: The reaction system temperature is 10-90° C., the acidity is 0-10 mol / L, the concentrations of zirconium and hafnium are both 0.01-3.0 mol / L, and the ratio of zirconium to hafnium is 80-99:20-1.

3. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 1, characterized in that: The coordination ion is F - 、Cl - Br - , I - 、CN - 、OCN - 、SCN _ 、I3 _ .

4. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 3, characterized in that: The neutral ligand is sulfoxide, alkyl-substituted thiourea or thiophosphoric triamide; The chemical formula of sulfoxide is R1-S=O-R2, where R1 and R2 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20; The chemical formula of the alkyl-substituted thiourea is R1R2NCSNR3R4, wherein R1, R2, R3, and R4 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20. The chemical formula of thiophosphoric triamide is PSN3R1R2R3R4R5R6, wherein R1, R2, R3, R4, R5, and R6 are alkane or alkene substituents with the same or different carbon atoms, and the number of carbon atoms is 4 to 20.

5. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 4, characterized in that: The neutral compound is one of benzene, alkyl-substituted benzene, biphenyl and olefin.

6. A supramolecular network of zirconium and hafnium complexes, characterized by: The compound is prepared by the preparation method according to any one of claims 1 to 5.

7. An application of a supramolecular network of zirconium and hafnium complexes, characterized by: The supramolecular network prepared according to claim 6 is applied to the separation of zirconium and hafnium.

8. The use of a supramolecular network of zirconium and hafnium complexes according to claim 7, characterized in that: The prepared supramolecular network is placed in an aqueous phase, and by changing the acidity of the aqueous phase and repeatedly contacting the supramolecular network, the separation of zirconium and hafnium is finally achieved.