Hydrophobic aminocarboxylic acid coordination system for comprehensively utilizing titanium, zirconium and hafnium from minerals

Abstract

The invention belongs to the technical field of comprehensive utilization of chemical substances in mineral resources, and particularly discloses a hydrophobic aminocarboxylic acid coordination system for comprehensively utilizing titanium, zirconium and hafnium from minerals, which comprises a hydrophobic ligand, a hydrophobic solvent and an aqueous solution of titanium, zirconium and hafnium, titanium, zirconium or hafnium and the hydrophobic ligand form a complex through a coordination bond or a feedback pi bond, the complex is effectively dissolved in a hydrophobic solvent to form a stable hydrophobic solution. The hydrophobic aminocarboxylic acid coordination system for comprehensively utilizing the titanium, zirconium and hafnium from the minerals can form hydrophobic aminocarboxylic acid coordination systems with different complex stability with titanium, zirconium and hafnium, and the system contains hydrophobic ligands and hydrophobic solvents for effectively dissolving the complexes. Chelate compounds with different stability are formed through a coordination system, titanium, zirconium, hafnium and the like, and then titanium, zirconium and hafnium are separated from one another.

Description

Technical Field

[0001] The invention relates to the field of comprehensive utilization of chemical substances in mineral resources, in particular to a hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals. Background Art

[0002] There is an important mineral sand in the mineral resources, which is an important raw material for the production of titanium, zirconium and hafnium. After the raw material is separated by water separation, electric separation or magnetic separation, zircon sand, ilmenite, rutile, monazite, xenotime and other minerals are separated. When zirconium and hafnium are extracted from zircon sand by alkali dissolution-acid leaching, high temperature chlorination-water and fluoride-mixed acid leaching, the solution contains not only zirconium and hafnium hydrate ions, but also titanium hydrate ions and the complex anions of these ions, such as [TiOCl 4 ] 2- 、[ZrCl 6 ] 2- , [HfCl 6 ] 2- 、[TiF 6 ] 2- , [ZrF 6 ] 2- and [HfF 6 ] 2- Etc. When preparing high-purity zirconium and hafnium products from these leachates, it is necessary to separate the fourth subgroup elements from other elements, and it is also necessary to face the problem of separating zirconium and hafnium, as well as the problem of separating titanium from zirconium and hafnium. The chemical properties of the fourth subgroup elements are quite different from those of other elements, and they can usually be separated by conventional methods, and the separation difficulty is relatively low. Compared with the atomic radius and ionic radius of zirconium and hafnium, the two radii of titanium are less than 10 and 13pm respectively, and the radii of zirconium and hafnium are extremely close due to lanthanide contraction. Therefore, it is easier to separate titanium from zirconium and hafnium, while it is more difficult to separate zirconium and hafnium. In order to achieve the separation of zirconium and hafnium, researchers have proposed many methods, and the most commercially valuable method is solvent extraction separation.

[0003] At present, among the patents on solvent extraction separation of zirconium and hafnium, few involve the separation of titanium from zirconium and hafnium. The solvents, separation media or separation processes for solvent extraction of zirconium and hafnium are mainly proposed. There are three main process routes for commercialized methods. One process route is to use zirconium oxychloride (hafnium) as raw material, add ammonium thiocyanate to the extraction system, and obtain zirconium and hafnium respectively by continuous countercurrent extraction with methyl isobutyl ketone. The second solvent extraction method for separating zirconium and hafnium is completed in a nitric acid medium. The extractant is tributyl phosphate (TBP) through a countercurrent extraction mode, and zirconium is extracted into the organic phase, while hafnium remains in the aqueous solution. The third solvent extraction process uses tertiary amines as extractants in a sulfuric acid medium to achieve the separation of zirconium and hafnium. For example, the patent with application number CN113234923A discloses a method for separating zirconium and hafnium using N235 in a sulfuric acid medium. Patent application number CN112593079A discloses a synergistic extractant and method for separating zirconium and hafnium. An alkaline amine extractant is added to a neutral phosphorus-containing extractant system to separate zirconium and hafnium in various media. Based on the above three separation methods, some new solvent extraction separation methods have been developed, such as the patent application number CN115710645A, which uses a tridentate amide acid to extract and separate nuclear-grade zirconium and nuclear-grade hafnium in a hydrochloric acid system. Patent application numbers CN115504901A and CN113981221A respectively disclose methods for separating and purifying zirconium and hafnium using an ionic liquid system. The cation is [A336] + , and the anions are several common anions.

[0004] In the currently disclosed methods for separating zirconium and hafnium, common and mature extractants are used, such as acidic phosphonic acid extractants, neutral phosphine oxide and ketone extractants, and alkaline amine extractants. In order to improve the separation efficiency, a ligand or auxiliary extractant is added to the extraction system, such as ammonium thiocyanate or nitric acid. Some of these extractants have the disadvantages of being highly water-soluble, easily volatile, or difficult to separate. In addition to the extractant, the added ligand or auxiliary extractant in the raffinate increases the difficulty of comprehensive utilization or treatment of wastewater. Summary of the invention

[0005] The purpose of the present invention is to provide a hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals. The coordination agent can form a hydrophobic aminocarboxylic acid coordination system with different coordination stability with titanium, zirconium and hafnium. The system contains a hydrophobic ligand and a hydrophobic solvent that effectively dissolves these coordination complexes. The coordination system forms chelates with different stability with titanium, zirconium and hafnium, and then separates titanium, zirconium and hafnium from each other.

[0006] To achieve the above-mentioned purpose, the present invention provides a hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals, including a hydrophobic ligand, a hydrophobic solvent, and an aqueous solution of titanium, zirconium and hafnium. Titanium, zirconium or hafnium forms a complex with the hydrophobic ligand by a coordination bond or a feedback π bond, and the complex is effectively dissolved in the hydrophobic solvent to form a stable hydrophobic solution.

[0007] Preferably, the hydrophobic ligand is a monoalkylaminodicarboxylic acid, a di-alkylaminomonocarboxylic acid, or a di-alkyldiaminodicarboxylic acid, wherein the alkyl group in the alkylaminocarboxylic acid is a straight-chain or branched saturated or unsaturated alkyl or aromatic hydrocarbon having 6 to 20 carbon atoms, and the carboxylic acid group is one of acetic acid, propionic acid, or butyric acid groups.

[0008] Preferably, the hydrophobic ligand is a di-alkyldiaminodicarboxylic acid, wherein the alkyl group is a straight-chain or branched saturated or unsaturated alkyl or aromatic hydrocarbon with 6-20 carbon atoms, the alkyl group between the two amino groups has 2-6 carbon atoms and is a straight-chain alkane, and the carboxylic acid group is one of acetic acid, propionic acid, and butyric acid groups.

[0009] Preferably, the hydrophobic solvent is a hydrophobic straight-chain or branched alkane, alkene or substituted aromatic hydrocarbon, and the number of carbon atoms is in the range of 8-20.

[0010] Preferably, the aqueous solution of titanium, zirconium and hafnium is one or two of the complexes of sulfate, chloride and fluorine, the concentration range of titanium, zirconium and hafnium elements is 0.0001-1.5 mol / L, and the hydrogen ion concentration range is 0.1-10 mol / L.

[0011] The advantages and beneficial effects of the hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium using the above-mentioned mineral are as follows: The system of the present invention contains a hydrophobic ligand and a hydrophobic solvent. Titanium, zirconium or hafnium forms a complex with the hydrophobic ligand by means of coordination bonds or feedback π bonds. The complex is dissolved in the hydrophobic solvent to form a stable hydrophobic solution. The stability of the hydrophobic complex varies with the process conditions of the hydrophobic ligand, the hydrophobic solvent and the aqueous solutions of titanium, zirconium and hafnium. This difference is utilized to separate titanium, zirconium and hafnium from each other.

[0012] The technical solution of the present invention is further described in detail below through embodiments. DETAILED DESCRIPTION

[0013] The technical solution of the present invention is further illustrated by the following examples.

[0014] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0015] Unless otherwise defined, the reagents used in the present invention are commercially available.

[0016] A hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive mineral utilization. The coordination system is used to separate metal titanium, zirconium and hafnium in ore sand, and comprises a hydrophobic ligand, a hydrophobic solvent, and an aqueous solution of titanium, zirconium and hafnium. Titanium, zirconium or hafnium forms a complex with the hydrophobic ligand by a coordination bond or a feedback π bond, and the complex is effectively dissolved in the hydrophobic solvent to form a stable hydrophobic solution.

[0017] The hydrophobic ligand is a monoalkylaminodicarboxylic acid, a dialkylaminomonocarboxylic acid, a dialkyldiaminodicarboxylic acid, wherein the alkyl group in the alkylaminocarboxylic acid is a straight chain or branched saturated or unsaturated alkyl or aromatic hydrocarbon having 6 to 20 carbon atoms, and the carboxylic acid group is an acetic acid, propionic acid, or butyric acid group, such as hexadecylaminodiacetic acid, di-hexadecylaminoacetic acid, octadecylaminodipropionic acid, di-octadecylaminopropionic acid, dodecylaminodibutyric acid, and di-dodecylaminobutyric acid.

[0018] The hydrophobic ligand is a di-alkyl diamino dicarboxylic acid, wherein the alkyl group is a straight chain or branched chain saturated or unsaturated alkyl group or aromatic hydrocarbon with 6-20 carbon atoms, the alkyl group between the two amino groups has 2-6 carbon atoms and is a straight chain alkane, and the carboxylic acid group is an acetic acid, propionic acid, or butyric acid group, such as di-hexadecyl propylene diamino diacetic acid, di-hexadecyl butyl diamino dipropionic acid, di-octadecyl ethylene diamino diacetic acid, di-octadecyl ethylene diamino malonic acid, di-dodecyl propylene diamino dibutyric acid, and di-dodecyl ethylene diamino dibutyric acid.

[0019] The hydrophobic solvent is a hydrophobic straight-chain or branched alkane, alkene or substituted aromatic hydrocarbon, and the number of carbon atoms ranges from 8 to 20.

[0020] The aqueous solution of titanium, zirconium and hafnium is one or two of the complexes of sulfate, chloride and fluorine, the concentration range of titanium, zirconium and hafnium elements is 0.0001-1.5 mol / L, and the hydrogen ion concentration range is 0.1-10 mol / L.

[0021] Example 1 The ore sand containing titanium, zirconium and hafnium in the mineral resources is leached with hydrochloric acid to obtain a hydrochloric acid solution containing titanium, zirconium and hafnium, and the solution is used as a raw material for comprehensive utilization of titanium, zirconium and hafnium in hydrochloric acid medium. The aqueous solution of titanium, zirconium and hafnium in hydrochloric acid medium has a hydrogen ion concentration of 1.3 mol / L, and the ion concentrations of titanium, zirconium and hafnium are 1.05 g / L (0.02 mol / L), 29.13 g / L (0.3 mol / L) and 0.81 g / L (0.0046 mol / L), respectively; the hydrophobic ligand is di-hexadecylaminoacetic acid, with a concentration of 1.3 mol / L, and the hydrophobic solvent is dodecylbenzene. At 50°C, the aqueous solution of titanium, zirconium and hafnium in hydrochloric acid medium and the hydrophobic solvent are fully mixed in a volume ratio of 2:1, and then allowed to stand for stratification after mixing.

[0022] The analysis results show that 98% of titanium ions remain in the aqueous solution, while 99.5% of zirconium and 99.2% of hafnium are transferred to the hydrophobic solvent, achieving the separation of titanium from zirconium and hafnium. The organic solvent is washed with a 2.5 mol / L hydrochloric acid solution, and almost 100% of the titanium remaining in the organic solution is washed down and enters the washing solution, with the loss rates of zirconium and hafnium being 3% and 1%, respectively. The zirconium and hafnium organic solutions washed with hydrochloric acid are fully mixed with 3 mol / L hydrochloric acid, and then allowed to stand for stratification to obtain a hafnium oxychloride solution, in which 98% of the hafnium enters the aqueous solution, and 0.12% of the zirconium enters the aqueous solution, achieving the separation of zirconium and hafnium.

[0023] Example 2 The hafnium oxychloride solution obtained in Example 1 was concentrated to obtain a chloride solution of 20.43 g / L hafnium and 0.88 g / L zirconium, with a hydrogen ion concentration of 3.7 mol / L. The solution was extracted with a dodecylbenzene solution of 32% by volume of di-dodecylethylenediaminodipropionic acid at a volume ratio of 1:1.5, and 99.8% of zirconium and 98.5% of hafnium were transferred to an organic solvent. The organic phase was washed with a 3 mol / L hydrochloric acid solution at a volume ratio of 1:1, and 94% of hafnium and 0.02% of zirconium were transferred to an aqueous solution, with a hafnium concentration of 18.92 g / L and a zirconium concentration of 0.00018 g / L.

[0024] Example 3 The ore sand containing titanium, zirconium and hafnium in the mineral resources is leached with sulfuric acid to obtain a sulfuric acid solution containing titanium, zirconium and hafnium, and the solution is used as a raw material for comprehensive utilization of titanium, zirconium and hafnium in the sulfuric acid medium. The aqueous solution of titanium, zirconium and hafnium in the sulfuric acid medium has a hydrogen ion concentration of 3 mol / L, and the ion concentrations of titanium, zirconium and hafnium are 1.31 g / L (0.025 mol / L), 38.59 g / L (0.40 mol / L) and 1.09 g / L (0.0050 mol / L), respectively; the hydrophobic ligand is di-hexadecylaminoacetic acid, the concentration is 1.30 mol / L, and the hydrophobic solvent is dodecylbenzene. At 50°C, the aqueous solution of titanium, zirconium and hafnium in the sulfuric acid medium and the hydrophobic solvent are fully mixed in a volume ratio of 2:1, and then allowed to stand for stratification after mixing.

[0025] The analysis results show that 99.50% of titanium ions remain in the aqueous solution, while 98.0% of zirconium and 95.0% of hafnium are transferred to the organic solvent, achieving the separation of titanium from zirconium and hafnium. The organic solvent is washed with a 1.5mol / L sulfuric acid solution, and almost 100% of the titanium remaining in the organic solution is washed down and enters the washing solution, with the loss rates of zirconium and hafnium being 10.0% and 6.0%, respectively. The zirconium and hafnium organic solutions washed with sulfuric acid are fully mixed with 3mol / L hydrochloric acid, and then allowed to stand for stratification, 98% of the hafnium enters the aqueous solution, and the zirconium that enters the aqueous solution is 0.02%, obtaining a hafnium oxychloride solution. The separation of zirconium and hafnium is achieved.

[0026] Example 4 The hafnium oxychloride solution obtained in Example 3 was concentrated to obtain a chloride solution of 15.32 g / L hafnium and 0.11 g / L zirconium, with a hydrogen ion concentration of 3.5 mol / L. The solution was extracted with a 25% di-dodecylethylenediaminodipropionic acid dodecylbenzene solution at a volume ratio of 1.5:1, and 96% of zirconium and 97% of hafnium were transferred to an organic solvent. The organic phase was washed with a 3 mol / L hydrochloric acid solution, and 95% of hafnium and 0.01% of zirconium were transferred to an aqueous solution, with a hafnium concentration of 14.12 g / L and a zirconium concentration of 0.000011 g / L.

[0027] Example 5 The ore sand containing titanium, zirconium and hafnium in the mineral resources is leached by sulfuric acid-hydrofluoric acid mixed solution to obtain sulfuric acid-hydrofluoric acid solution containing titanium, zirconium and hafnium, and the solution is used as raw material for comprehensive utilization of titanium, zirconium and hafnium. The aqueous solution of titanium, zirconium and hafnium in sulfuric acid-fluoride medium has a hydrogen ion concentration of 0.3 mol / L, and the ion concentrations of titanium, zirconium and hafnium are 2.05 (0.04 mol / L), 40.26 (0.44 mol / L) and 1.13 g / L (0.0063 mol / L), respectively; the hydrophobic ligand is di-hexadecylaminoacetic acid, the concentration is 1.3 mol / L, and the hydrophobic solvent is dodecylbenzene. At 50°C, the aqueous solution of titanium, zirconium and hafnium in sulfuric acid-fluoride medium and the hydrophobic solvent are fully mixed in a volume ratio of 3.5:1, and then allowed to stand for stratification after mixing.

[0028] The analysis results show that 98% of titanium ions remain in the aqueous solution, while 99.5% of zirconium and 99.2% of hafnium are transferred to the organic solvent, achieving the separation of titanium from zirconium and hafnium. The organic solvent is washed with a 2.5mol / L hydrochloric acid solution, and almost 99.5% of the titanium remaining in the organic solution is washed down and enters the washing solution, with the loss rates of zirconium and hafnium being 3% and 1%, respectively. The zirconium and hafnium organic solutions washed with hydrochloric acid are fully mixed with 3mol / L hydrochloric acid, and then allowed to stand for stratification to obtain a hafnium oxychloride solution, in which 98% of the hafnium enters the aqueous solution, and the zirconium that enters the aqueous solution is 0.012%. The separation of zirconium and hafnium is achieved.

[0029] Example 6 The hafnium oxychloride solution obtained in Example 5 was concentrated to obtain a chloride solution of 26.22 g / L hafnium and 0.11 g / L zirconium, with a hydrogen ion concentration of 3.5 mol / L. The solution was extracted with a volume ratio of 25% di-dodecylethylenediaminodipropionic acid in isomeric tetradecanol and hexadecanol (a mixture of isomeric tetradecanol and isomeric hexadecanol) at a volume ratio of 1.2 to 1, and 96% of zirconium and 97% of hafnium were transferred to an organic solvent. The organic phase was washed with a 4 mol / L hydrochloric acid solution at a volume ratio of 1:1, and 95% of hafnium and 0.01% of zirconium were transferred to an aqueous solution, with a hafnium concentration of 14.12 g / L and a zirconium concentration of 0.000011 g / L.

[0030] Therefore, the present invention adopts the above-mentioned mineral comprehensive utilization of the hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium, which can form a hydrophobic aminocarboxylic acid coordination system with different coordination stability with titanium, zirconium and hafnium. The system contains hydrophobic ligands and a hydrophobic solvent that effectively dissolves these coordination complexes. The coordination system forms chelates with different stability with titanium, zirconium and hafnium, and then separates titanium, zirconium and hafnium from each other.

[0031] 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 hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive mineral utilization, characterized in that: The invention comprises a hydrophobic ligand, a hydrophobic solvent, and an aqueous solution of titanium, zirconium and hafnium. Titanium, zirconium or hafnium and the hydrophobic ligand form a complex by a coordination bond or a feedback π bond. The complex is effectively dissolved in the hydrophobic solvent to form a stable hydrophobic solution.

2. The hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals according to claim 1, characterized in that: The hydrophobic ligand is one of monoalkylaminodicarboxylic acid, di-alkylaminomonocarboxylic acid, and di-alkyldiaminodicarboxylic acid, wherein the alkyl group in the alkylaminocarboxylic acid is a straight chain or branched saturated or unsaturated alkyl or aromatic hydrocarbon with 6 to 20 carbon atoms, and the carboxylic acid group is one of acetic acid, propionic acid, and butyric acid groups.

3. The hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals according to claim 1, characterized in that: The hydrophobic ligand is a di-alkyl diamino dicarboxylic acid, wherein the alkyl group is a straight chain or branched saturated or unsaturated alkyl or aromatic hydrocarbon with 6-20 carbon atoms, the alkyl group between the two amino groups has 2-6 carbon atoms and is a straight chain alkane, and the carboxylic acid group is one of acetic acid, propionic acid, and butyric acid groups.

4. The hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals according to claim 1, characterized in that: The hydrophobic solvent is a hydrophobic straight-chain or branched alkane, alkene or substituted aromatic hydrocarbon, and the number of carbon atoms is in the range of 8-20.

5. The hydrophobic aminocarboxylic acid coordination system of titanium, zirconium and hafnium for comprehensive utilization of minerals according to claim 1, characterized in that: The aqueous solution of titanium, zirconium and hafnium is one or two of the complexes of sulfate, chloride and fluorine. The concentration range of titanium, zirconium and hafnium elements is 0.0001-1.5 mol / L, and the concentration range of hydrogen ions is 0.1-10 mol / L.