阅读说明：本技术 一种无水稀土卤化物的制备方法 (Preparation method of anhydrous rare earth halide ) 是由 高淞 汪瑞 张瑞森 李璐 张光睿 赵长玉 彭维 王安丽 于 2021-10-11 设计创作，主要内容包括：本发明创造提供了一种无水稀土卤化物的制备方法,包括如下步骤：S1：将含结晶水的水合稀土卤化物溶于乙醇溶液得到稀土醇溶液；S2：将稀土醇溶液进行一次加热同时减压蒸馏使溶液中的乙醇蒸发脱除得到稀土溶液；S3：将卤化铵加热,使稀土溶液在所述卤化铵加热过程中产生的气体的氛围下进行二次加热脱水,脱水完成后降至室温得到无水稀土卤化物,取出封装。本发明创造所述的方法制备出的无水稀土卤化物含水量≤0.5％,稀土卤氧化物≤0.5％,提高了稀土卤化物的纯度。(The invention provides a preparation method of anhydrous rare earth halide, which comprises the following steps: s1: dissolving hydrated rare earth halide containing crystal water in an ethanol solution to obtain a rare earth alcohol solution; s2: heating the rare earth alcohol solution for the first time and distilling under reduced pressure to evaporate and remove ethanol in the solution to obtain a rare earth solution; s3: heating ammonium halide to ensure that the rare earth solution is heated and dehydrated for the second time in the atmosphere of gas generated in the heating process of the ammonium halide, cooling to room temperature after dehydration is finished to obtain anhydrous rare earth halide, taking out and packaging. The anhydrous rare earth halide prepared by the method has the water content of less than or equal to 0.5 percent and the rare earth oxyhalide of less than or equal to 0.5 percent, and improves the purity of the rare earth halide.)

1. A preparation method of anhydrous rare earth halide is characterized by comprising the following steps: the method comprises the following steps:

s1: dissolving hydrated rare earth halide containing crystal water in an ethanol solution to obtain a rare earth alcohol solution;

s2: heating the rare earth alcohol solution for the first time and distilling under reduced pressure to evaporate and remove ethanol in the solution to obtain a rare earth solution;

s3: heating ammonium halide to ensure that the rare earth solution is heated and dehydrated for the second time in the atmosphere of gas generated in the heating process of the ammonium halide, cooling to room temperature after dehydration is finished to obtain anhydrous rare earth halide, taking out and packaging.

2. The method of claim 1, wherein the method comprises: the mass ratio of the hydrated rare earth halide to the ethanol to the ammonium halide is 1 (1-3) to 1-4, and the concentration of the ethanol solution is 99%.

3. The method of claim 1, wherein the method comprises: the vacuum condition of the reduced pressure distillation in the step S2 is-0.03 MPa to-0.1 MPa.

4. The method of claim 1, wherein the method comprises: the heating temperature of the ammonium halide in the step S3 is 260-340 ℃.

5. The method for producing an anhydrous rare earth halide according to claim 1, wherein: the ethanol removal time of the step S2 is 1min-600 min.

6. The method for producing an anhydrous rare earth halide according to claim 4, wherein: the primary heating temperature of the step S2 and the secondary heating temperature of the step S3 are both 60-360 ℃.

7. The method for producing an anhydrous rare earth halide according to claim 1, wherein: the time for the secondary heating dehydration in the step S3 is 1-600 min.

8. The method for producing an anhydrous rare earth halide according to claim 1, wherein: the hydrated rare earth halide is LnX₃·nH₂O and Ln are any one or more elements of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and Sc, X is any one or more elements of Cl and Br, and n is less than or equal to 7.

9. The method for producing an anhydrous rare earth halide according to claim 1, wherein: the container used in the preparation method is a non-metallic container and comprises one or more mixed materials of quartz glass, silicate glass, crystal glass, enamel, corundum, alumina, silicon oxide and zirconium oxide.

Technical Field

The invention belongs to the field of anhydrous rare earth halide preparation processes, and particularly relates to a preparation method of an anhydrous rare earth halide.

Background

The anhydrous rare earth halide is an important raw material in the manufacturing industry, and has important and wide application prospect in the fields of luminescent materials, heat insulation materials, hydrogen storage materials, ceramic materials, catalysis, military industry and the like. Due to the characteristic that the rare earth halide is extremely easy to deliquesce, a large amount of impurities such as oxyhalides and oxides are easily generated due to deliquescence in the process of preparing the anhydrous rare earth halide, so that the preparation of the anhydrous rare earth halide is extremely difficult.

At present, the main method for preparing anhydrous rare earth halide is to dehydrate hydrated rare earth halide to prepare anhydrous rare earth halide. The method for dehydrating the hydrated rare earth halide roughly comprises the following steps: (1) directly heating in air for dehydration; (2) heating and dehydrating under the protection of inert atmosphere or under vacuum condition; (3) heating and dehydrating under the protection of ammonium halide; (4) introducing hydrogen halide gas for protection, heating and dehydrating. The water and oxygen in the air are easy to deliquesce and react with the rare earth halide by directly heating in the air atmosphere, so that the prepared anhydrous rare earth halide contains a large amount of oxyhalide and oxide impurities; in order to solve the problem of deliquescence and oxidation, dehydration is carried out under the condition of introducing protective atmosphere or vacuum, and the method can inhibit deliquescence to a certain extent under the condition of strictly controlling the temperature rise rate and the temperature interval. However, the above conventional methods have problems such as unsatisfactory dehydration effect and serious hydrolysis.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing anhydrous rare earth halide, which aims to overcome the defects in the prior art.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a preparation method of anhydrous rare earth halide comprises the following steps:

s1: dissolving hydrated rare earth halide containing crystal water in an ethanol solution to obtain a rare earth alcohol solution;

s2: heating the rare earth alcohol solution for the first time and distilling under reduced pressure to evaporate and remove ethanol in the solution to obtain a rare earth solution;

s3: heating ammonium halide to ensure that the rare earth solution is heated and dehydrated for the second time in the atmosphere of gas generated in the heating process of the ammonium halide, cooling to room temperature after dehydration is finished to obtain anhydrous rare earth halide, taking out and packaging.

Preferably, the mass ratio of the hydrated rare earth halide to the ethanol to the ammonium halide is 1 (1-3) to (1-4), and the concentration of the ethanol solution is 99%.

Preferably, the vacuum condition of the reduced pressure distillation in the step S2 is-0.03 MPa to-0.1 MPa.

Preferably, the heating temperature of the ammonium halide in the step S3 is 260 ℃ to 340 ℃.

Preferably, the ethanol removal time of step S2 is 1min to 600 min.

Preferably, the temperature of the primary heating in the step S2 and the temperature of the secondary heating in the step S3 are both 60 ℃ to 360 ℃.

Preferably, the time for the secondary heating dehydration in the step S3 is 1min-600 min.

Preferably, the hydrated rare earth halide is LnX₃·nH₂O and Ln are any one or more elements of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y and Sc, X is any one or more elements of Cl and Br, and n is less than or equal to 7.

Preferably, the container used in the preparation method is a non-metallic container, and comprises one or more of a quartz glass material, a silicate glass material, a crystal glass material, an enamel material, a corundum material, an alumina material, a silica material and a zirconia material.

Compared with the prior art, the invention has the following advantages:

the invention adopts a dehydration method combining ethanol azeotropy and protective atmosphere, firstly removes part of crystal water in hydrated rare earth halide through ethanol azeotropy, and then further dehydrates by taking hydrogen halide gas generated by heating ammonium halide as protective atmosphere, so that the water content of the prepared anhydrous rare earth halide is less than or equal to 0.5 percent, the rare earth oxyhalide is less than or equal to 0.5 percent, and the purity of the rare earth halide is improved. The dehydration time is short, the dehydration effect is good, the problem of material hydrolysis is greatly reduced, in addition, the ethanol distilled by the dehydration method can be recycled, and the energy conservation and emission reduction are realized in the aspect of material cost.

Detailed Description

Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.

The invention will be described in detail with reference to the following examples.

Example 1

A method for preparing anhydrous rare earth halide comprises the steps of dissolving 800g of cerium chloride heptahydrate with the water content of 33% in 1L of ethanol solution to obtain a rare earth alcohol solution, pouring the rare earth alcohol solution into a glass rotary steaming bottle, performing rotary steaming, and vacuumizing to-0.1 MPa. Heating the rotary evaporation bottle to 60 ℃ for reduced pressure distillation. After 1 hour the ethanol had evaporated, and the single neck flask containing 1kg of ammonium chloride was placed in a salt bath and heated to 280 ℃. And (3) connecting a conduit of the single-mouth flask into the rotary evaporation bottle, raising the heating temperature of the rotary evaporation bottle to 340 ℃, finishing dehydration after 2 hours, cooling to room temperature, pouring out the product and packaging. 531g of anhydrous cerium chloride with a purity of 99.99% was obtained, which was assayed for a water content of 0.12% and a rare earth oxyhalide of 0.41%.

Example 2

A method for preparing anhydrous rare earth halide comprises the steps of dissolving 200g of erbium chloride hexahydrate with the water content of 30% in 400mL of ethanol solution to obtain a rare earth alcohol solution, pouring the rare earth alcohol solution into a glass rotary steaming bottle, performing rotary steaming, and vacuumizing to-0.098 MPa. Heating the rotary evaporation bottle to 60 ℃ for reduced pressure distillation. After 0.6 hour the ethanol had evaporated and the single neck flask containing 200g of ammonium chloride was placed in a salt bath kettle and heated to 280 ℃. And (3) connecting a conduit of the single-mouth flask into the rotary evaporation bottle, raising the heating temperature of the rotary evaporation bottle to 330 ℃, finishing dehydration after 1 hour, cooling to room temperature, pouring out the product and packaging. 135g of anhydrous erbium chloride with the purity of 99.9 percent is obtained, and the detection and analysis of the anhydrous erbium chloride show that the water content is 0.07 percent and the rare earth oxyhalide is 0.08 percent.

Example 3

A method for preparing anhydrous rare earth halide comprises the steps of dissolving 500g of lanthanum bromide heptahydrate with the water content of 33% in 800mL of ethanol solution to obtain a rare earth alcohol solution, pouring the rare earth alcohol solution into a glass rotary evaporation bottle, performing rotary evaporation in a connecting manner, and vacuumizing to-0.09 MPa. Heating the rotary evaporation bottle to 60 ℃ for reduced pressure distillation. After 1 hour the ethanol had evaporated and the single neck flask containing 600g of ammonium bromide was placed in a salt bath and heated to 280 ℃. And (3) connecting a conduit of the single-mouth flask into the rotary evaporation bottle, raising the heating temperature of the rotary evaporation bottle to 340 ℃, finishing dehydration after 1.5 hours, cooling to room temperature, pouring out the product and packaging. 334g of anhydrous lanthanum bromide with the purity of 99.9 percent is obtained, and the detection and analysis show that the moisture content of the anhydrous lanthanum bromide is 0.03 percent and the rare earth oxyhalide is 0.11 percent.

Example 4

A method for preparing anhydrous rare earth halide comprises the steps of dissolving 1kg of ytterbium bromide hexahydrate with the water content of 30% in 1200mL of ethanol solution to obtain a rare earth alcohol solution, pouring the rare earth alcohol solution into a glass rotary steaming bottle, performing rotary steaming in a connecting mode, and vacuumizing to-0.098 MPa. Heating the rotary evaporation bottle to 60 ℃ for reduced pressure distillation. After 2 hours the ethanol had evaporated and the single neck flask containing 1200g of ammonium bromide was placed in a salt bath and heated to 280 ℃. And (3) connecting a conduit of the single-mouth flask into the rotary evaporation bottle, raising the heating temperature of the rotary evaporation bottle to 320 ℃, finishing dehydration after 2.5 hours, cooling to room temperature, pouring out the product and packaging. 663g of anhydrous ytterbium bromide with a purity of 99.9% was obtained, and the anhydrous lanthanum bromide was analyzed by detection to have a water content of 0.09% and a rare earth oxyhalide content of 0.21%.

Comparative example 1:

dissolving 800g of cerium chloride heptahydrate with the water content of 33 percent in 1L of ethanol solution to obtain a rare earth alcohol solution, then pouring the rare earth alcohol solution into a glass rotary evaporation bottle, connecting rotary evaporation, and vacuumizing to-0.1 MPa. Heating the rotary evaporation bottle to 60 ℃ for reduced pressure distillation. After 1 hour the ethanol evaporated. 673g of anhydrous cerium chloride is prepared, which has a water content of 8.9%, a purity of 99.9% and a rare earth oxyhalide of 9.8% by detection.

Comparative example 2:

1kg of ytterbium bromide hexahydrate with the water content of 30 percent is put into a glass rotary steaming bottle, connected and rotary steamed, and vacuumized to-0.098 MPa. A single neck flask containing 1200g of ammonium bromide was placed in a salt bath kettle and heated to 280 ℃. And (3) connecting a conduit of the single-mouth flask into the rotary evaporation bottle, raising the heating temperature of the rotary evaporation bottle to 320 ℃, finishing dehydration after 10 hours, cooling to room temperature, pouring out the product and packaging. 630g of anhydrous ytterbium bromide with the purity of 99.9 percent is obtained, and the detection and analysis shows that the moisture content of the anhydrous lanthanum bromide is 1.3 percent and the rare earth oxyhalide is 10.9 percent.

As can be seen from the result data of examples 1-4 and comparative examples 1-2, the invention innovatively adopts the operation of 'ethanol azeotropic dehydration' before the heating dehydration in the ammonium halide protective atmosphere, so that the decomposition of the rare earth oxyhalide can be reduced, and the purity of the finished anhydrous rare earth halide can be obviously improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the invention, so that any modifications, equivalents, improvements and the like, which are within the spirit and principle of the present invention, should be included in the scope of the present invention.