Preparation method and application of zirconium and hafnium complex supramolecular network

Abstract

The invention discloses a preparation method and application of a zirconium and hafnium complex supramolecular network, and belongs to the technical field of zirconium and hafnium separation. Zirconium or hafnium and coordination ions or neutral ligands form a planar quadrilateral compound in a coordination bond or ionic association mode, and the planar quadrilateral compound and a neutral compound containing pi bonds or delocalized pi bonds form a supramolecular network through p-pi accumulation and pi-pi accumulation. Based on the characteristic that the planar quadrilateral compounds of zirconium and hafnium have different stability along with different process conditions in a supramolecular network, the separation of zirconium and hafnium is realized; compared with a traditional method, the method does not need to use an extraction system of mixed acid or a mixed extraction agent, and solves the problems of environmental pollution caused by discharge of a large amount of waste acid and waste alkali and flammable and explosive extraction agents.

Description

Technical Field

[0001] The 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] In nature, Zr and Hf coexist in an isomorphous manner, and there are no separate zirconium or hafnium ores. The mass content of Hf in Zr chemicals is about 1-3% of Zr. In practical applications, high-purity zirconium or hafnium products are required, so a suitable separation method is needed to separate and purify zirconium and hafnium in the mixture. As a result of lanthanide contraction, the physicochemical properties of zirconium and hafnium are similar, and the separation of zirconium and hafnium is difficult. The industrial methods for separating Zr and Hf include fractional crystallization, molten salt distillation, ion exchange and solvent extraction. Among them, solvent extraction has the advantages of large processing capacity, low cost and easy continuous production, and has become the most important method for separating Zr and Hf. The widely used extraction separation processes are: MIBK-NH4SCN method, that is, the organic phase is MIBK and the aqueous phase contains NH4SCN; TBP-HNO3-HCl method, that is, the extractant is TBP and the aqueous phase medium is HNO3-HCl mixed acid medium; TOA / N235-H2SO4 method, that is, the extractant is tertiary amine and the aqueous phase is sulfate. Most of these solvent extraction separation methods extract all or part of the zirconium and hafnium in the mixed solution into the organic phase, and then wash and back extract to obtain zirconium and hafnium products respectively.

[0003] The existing methods for separating zirconium and hafnium mostly use the commonly used acidic phosphonic acid extractants, neutral phosphine oxide and ketone extractants, and alkaline amine extractants. These extraction systems often have problems such as slow phase separation, small separation coefficient, serious environmental pollution caused by the added coordination ions, and difficulty in handling, as well as some extractants with low boiling points and flammability and explosion.

[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, the steps of which are as follows:

[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, and then a compound containing a coordinated ion or a neutral ligand is added to react to obtain a planar quadrilateral compound; then a neutral compound is added thereto to react to obtain a supramolecular network.

[0008] Preferably, the temperature of the reaction system 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 coordinating 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, wherein 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 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 contacted with the supramolecular network repeatedly 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, wherein zirconium or hafnium forms a planar quadrilateral compound with a coordination ion or a neutral ligand in the form of a coordination bond or ion association, 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 the traditional method, the method does not require the use of a mixed acid or mixed extractant extraction system, thereby solving the environmental pollution caused by the discharge of a large amount of waste acid and waste alkali and the flammable and explosive problems of the extractant.

[0021] The technical solution of the present invention is further described in detail below through embodiments. 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, rather than all the embodiments.

[0024] Example 1

[0025] Under the conditions of system temperature of 30°C and 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, and the ionic ligands of zirconium and hafnium were chloride ions. After a period of reaction, 1,3-dodecadiene was added thereto to react and form a supramolecular network.

[0026] Then, the acidity of the aqueous phase was changed to 2.8 mol / L, and the reaction was repeated for several times and brought into contact 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] Under the conditions of system temperature of 30°C and 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, and after a period of reaction, 1,3-dodecadiene was added thereto to react and form a supramolecular network.

[0029] Then, the acidity of the aqueous phase was changed to 2.8 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 40°C and acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%) were added to a hydrochloric acid medium, followed by the addition of 2.5 mol / L sodium bromide; the ionic ligands of zirconium and hafnium are chloride and bromide ions; after a period of reaction, mesitylene was added thereto to react and form a supramolecular network.

[0032] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 40°C and acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%) were added to a hydrochloric acid medium, followed by the addition of N,N,N,N-tetra-octylthiourea; after a period of reaction, mesitylene was added thereto to react and form a supramolecular network.

[0035] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 50°C and 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%) respectively was added to a hydrochloric acid medium, followed by the addition of 2.0 mol / L sodium thiocyanate; the ionic ligands of zirconium and hafnium are chlorine and thiocyanate ions; after a period of reaction, a mixture of mesitylene and 1,3-dodecadiene was added thereto to react and form a supramolecular network.

[0038] Then, the acidity of the aqueous phase was changed to 3.6 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 50°C and 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 thereto to react and form a supramolecular network.

[0041] Then, the acidity of the aqueous phase was changed to 3.6 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 40°C and acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%) were placed in a hydrochloric acid medium, followed by the addition of 2.5 mol / L sodium bromide, where the ionic ligands of zirconium and hafnium are 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 aqueous phase was contacted with the supramolecular network repeatedly 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] Under the conditions of system temperature of 40°C and acidity of 3.5 mol / L, solutions with zirconium and hafnium concentrations of 26.30 g / L and 0.68 g / L (2.6%) were 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 thereto to react and form a supramolecular network.

[0047] Then, the acidity of the aqueous phase was changed to 3.0 mol / L, and the aqueous phase was contacted with the supramolecular network repeatedly 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 the above Examples 1-8 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, wherein zirconium or hafnium is combined with a coordination ion or a neutral ligand to form a planar quadrilateral compound in the form of a coordination bond or ion association, and the planar quadrilateral compound and a neutral compound containing a π bond or a delocalized π bond are used to form a supramolecular network through p-π stacking and π-π stacking. Based on the fact that the planar quadrilateral compounds of zirconium and hafnium have different stability in the supramolecular network depending on the process conditions, the separation of zirconium and hafnium is achieved. Compared with the traditional method, the present method does not require the use of a mixed acid or mixed extractant extraction system, thereby solving the environmental pollution caused by the discharge of a large amount of waste acid and waste alkali and the flammable and explosive problems of the extractant.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. 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 solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution 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, and then a compound containing a coordinated ion or a neutral ligand is added to react to obtain a planar quadrilateral compound; then a neutral compound is added thereto to react to obtain a supramolecular network.

2. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 1, characterized in that: The temperature of the reaction system 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 a halogen ion or a pseudohalogen ion, specifically F - , Cl - Br - ,I - , CN - 、OCN - 、SCN _ 、I3 _ .

4. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 1, characterized in that: 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 π bonds or delocalized π bonds.

5. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 4, characterized in that: The neutral ligand is sulfoxide, alkyl-substituted thiourea or thiophosphoric triamide; The chemical formula of sulfoxide is R1-S=O-R2, wherein 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.

6. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 1, characterized in that: 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.

7. The method for preparing a supramolecular network of zirconium and hafnium complexes according to claim 6, characterized in that: The neutral compound is one of benzene, alkyl-substituted benzene, biphenyl, olefin or conjugated olefin compounds.

8. A supramolecular network of zirconium and hafnium complexes, characterized in that: The compound is prepared by the preparation method described in any one of claims 1 to 7.

9. An application of a supramolecular network of zirconium and hafnium complexes, characterized in that: The prepared supramolecular network was applied to the separation of zirconium and hafnium.

10. The use of a supramolecular network of zirconium and hafnium complexes according to claim 9, 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.