阅读说明：本技术 一种常压制备高纯无水氯化钕的制备方法 (Preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure ) 是由 周宏亮 陈敏 熊吉磊 陈吉华 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种常压制备高纯无水氯化钕的制备方法,包括以下步骤：S1、将含钕氧化物置于盐酸中并加热至65℃,保温30min以上,待含钕氧化物完全溶解后得到氯化钕溶液；S2、向氯化钕溶液中加入防氧化剂,得到初步混合溶液；S3、将初步混合溶液加热至自由水分蒸干,得到呈粘稠状的中间产物；S4、在中间产物中加入脱水剂,充分搅拌后将其置于氮气保护的烘干箱中,加热至80℃后保温30～60min；S5、继续升温至140～200℃后保温60min,将中间产物中的脱水剂完全分解；S6、继续升温至350℃以上,将中间产物中的防氧化剂完全分解,最终在氮气保护气氛中得到无水氯化钕。(The invention discloses a preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure, which comprises the following steps: s1, placing the neodymium-containing oxide in hydrochloric acid, heating to 65 ℃, and preserving heat for more than 30min to obtain a neodymium chloride solution after the neodymium-containing oxide is completely dissolved; s2, adding an antioxidant into the neodymium chloride solution to obtain a primary mixed solution; s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product; s4, adding a dehydrating agent into the intermediate product, fully stirring, placing in a nitrogen-protected drying box, heating to 80 ℃, and then preserving heat for 30-60 min; s5, continuously heating to 140-200 ℃, then preserving the heat for 60min, and completely decomposing the dehydrating agent in the intermediate product; and S6, continuously heating to above 350 ℃, completely decomposing the antioxidant in the intermediate product, and finally obtaining the anhydrous neodymium chloride in the nitrogen protective atmosphere.)

1. A preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure is characterized by comprising the following steps: the method comprises the following steps:

s1, placing the neodymium-containing oxide in hydrochloric acid, heating to 65 ℃, and preserving heat for more than 30min to obtain a neodymium chloride solution after the neodymium-containing oxide is completely dissolved;

s2, adding an antioxidant into the neodymium chloride solution to obtain a primary mixed solution;

s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product;

s4, adding a dehydrating agent into the intermediate product, fully stirring, placing in a nitrogen-protected drying box, heating to 80 ℃, and then preserving heat for 30-60 min;

s5, continuously heating to 140-200 ℃, then preserving the heat for 60min, and completely decomposing the dehydrating agent in the intermediate product;

and S6, continuously heating to above 350 ℃, completely decomposing the antioxidant in the intermediate product, and finally obtaining the anhydrous neodymium chloride in the nitrogen protective atmosphere.

2. The method for preparing high-purity anhydrous neodymium chloride under normal pressure as claimed in claim 1, wherein the method comprises the following steps: in step S1, the neodymium-containing oxide is one or a mixture of neodymium oxide, neodymium carbonate, and neodymium hydroxide.

3. The method for preparing high-purity anhydrous neodymium chloride under normal pressure as claimed in claim 2, wherein: in the step S1, the concentration of hydrochloric acid is 10 mol/L.

4. The method for preparing high-purity anhydrous neodymium chloride under normal pressure according to claim 3, which is characterized in that: in the step S1, the content of chloride in the neodymium chloride solution is more than 200 g/L.

5. The method for preparing high-purity anhydrous neodymium chloride under normal pressure according to claim 4, which is characterized in that: in the step S2, the mass of the antioxidant is 1-2 times of the mass of the chloride in the neodymium chloride solution; the antioxidant is ammonium chloride.

6. The method for preparing high-purity anhydrous neodymium chloride under normal pressure according to claim 5, which is characterized in that: in the step S4, the intermediate product is submerged when a dehydrating agent is added, wherein the dehydrating agent is SOCl₂。

Technical Field

The invention relates to the field of preparation of neodymium chloride, in particular to a preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure.

Background

The anhydrous neodymium chloride is mainly used in the industries of rubber, medicine and the like, only a few factories can produce the product at present, and the anhydrous neodymium chloride in the market is mainly prepared in a high vacuum environment, so that the preparation process is complex, the operation difficulty is high, the production cost of the anhydrous neodymium chloride is increased seriously, certain troubles are brought to the production work of the anhydrous neodymium chloride, the purity is also greatly limited, and particularly, the oxygen content is higher.

Disclosure of Invention

The invention aims to solve the problems and provides a preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure, which is simple to operate and low in cost.

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

a preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure comprises the following steps:

s1, placing the neodymium-containing oxide in hydrochloric acid, heating to 65 ℃, and preserving heat for more than 30min to obtain a neodymium chloride solution after the neodymium-containing oxide is completely dissolved;

s2, adding an antioxidant into the neodymium chloride solution to obtain a primary mixed solution;

s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product;

s4, adding a dehydrating agent into the intermediate product, fully stirring, placing in a nitrogen-protected drying box, heating to 80 ℃, and then preserving heat for 30-60 min;

s5, continuously heating to 140-200 ℃, then preserving the heat for 60min, and completely decomposing the dehydrating agent in the intermediate product;

and S6, continuously heating to above 350 ℃, completely decomposing the antioxidant in the intermediate product, and finally obtaining the anhydrous neodymium chloride in the nitrogen protective atmosphere.

Further, in step S1, the neodymium-containing oxide is one or a mixture of neodymium oxide, neodymium carbonate, and neodymium hydroxide.

Further, in the step S1, the concentration of hydrochloric acid is 10 mol/L;

it is also possible to choose a lower concentration of hydrochloric acid to dissolve the rare earth oxide, but considering that further evaporation of water is required in the later stage and concentration is required, it is a practical and economical solution to choose a concentration above 10 mol/L.

Further, in the step S1, the content of chloride in the neodymium chloride solution is greater than 200 g/L.

Further, in the step S2, the mass of the antioxidant is 1 to 2 times of the mass of the chloride in the neodymium chloride solution; the antioxidant is ammonium chloride.

Further, in the step S4, a dehydrating agent is added to submerge the intermediate product, wherein the dehydrating agent is SOCl₂。

The high purity of the present invention is understood in two parts, the first part being: high purity of raw material, Nd₂O₃The purity of (A) is more than 4N, and the other part is that the oxygen content of the product obtained by the invention is less than 30ppm, and the product is high-purity NdCl₃。

Compared with the prior art, the invention has the advantages and positive effects that:

dissolving neodymium-containing oxide by hydrochloric acid, then sequentially adding an antioxidant and a dehydrating agent to perform the next reaction, and finally completely decomposing the antioxidant and the dehydrating agent in the mixed material by a drying box to finally obtain dry and clean anhydrous neodymium chloride; the whole preparation process does not need to adopt a high-pressure environment, the production cost of the anhydrous neodymium chloride is effectively reduced, the preparation process is easy, simple and quick to operate, and a brand-new way is developed for the preparation process of the anhydrous neodymium chloride.

The method of the invention can also be used for producing other rare earth chlorides.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived from the embodiments of the present invention by a person skilled in the art without any creative effort, should be included in the protection scope of the present invention.

Embodiment 1, this embodiment discloses a method for preparing high-purity anhydrous neodymium chloride under normal pressure, which includes the following steps:

s1, putting neodymium oxide into hydrochloric acid with the concentration of 10mol/L, heating to 65 ℃, preserving heat for more than 30min, and obtaining a neodymium chloride solution after the neodymium oxide is completely dissolved, wherein the content of chloride in the neodymium chloride solution is more than 200 g/L;

s2, adding ammonium chloride into the neodymium chloride solution to obtain a primary mixed solution; the mass of the ammonium chloride is 1 time of that of the chloride in the neodymium chloride solution;

s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product;

s4, adding SOCl into the intermediate product₂，SOCl₂Submerging the intermediate product; stirring thoroughly, placing in a nitrogen-protected oven, heating to 80 deg.C, and keeping the temperature for 30 min;

s5, continuously heating to 140 ℃, then preserving the heat for 60min, and adding SOCl in the intermediate product₂Completely decomposing;

and S6, continuing to heat to 350 ℃, completely decomposing ammonium chloride in the intermediate product, and finally obtaining anhydrous neodymium chloride in a nitrogen protective atmosphere, wherein an oxygen analyzer is adopted to test the oxygen content of the anhydrous neodymium chloride to be 22ppm, and the water content is less than 10 ppm.

Embodiment 2 and this embodiment disclose a preparation method for preparing high-purity anhydrous neodymium chloride under normal pressure, which includes the following steps:

s1, placing neodymium carbonate in hydrochloric acid with the concentration of 10mol/L, heating to 65 ℃, preserving heat for more than 30min, and obtaining a neodymium chloride solution after the neodymium carbonate is completely dissolved, wherein the content of chloride in the neodymium chloride solution is more than 200 g/L;

s2, adding ammonium chloride into the neodymium chloride solution to obtain a primary mixed solution; the mass of the ammonium chloride is 2 times of that of the chloride in the neodymium chloride solution;

s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product;

s4, adding SOCl into the intermediate product₂，SOCl₂Submerging the intermediate product; stirring thoroughly, placing in a nitrogen-protected oven, heating to 80 deg.C, and keeping the temperature for 50 min;

s5, continuously heating to 180 ℃, preserving the heat for 60min, and adding SOCl in the intermediate product₂Completely decomposing;

and S6, continuing to heat to 360 ℃, completely decomposing ammonium chloride in the intermediate product, and finally obtaining anhydrous neodymium chloride in a nitrogen protective atmosphere, wherein an oxygen analyzer is adopted to test the oxygen content of the anhydrous neodymium chloride to be 18ppm, and the water content of the anhydrous neodymium chloride to be less than 10 ppm.

Embodiment 3, this embodiment discloses a method for preparing high-purity anhydrous neodymium chloride under normal pressure, which includes the following steps:

s1, placing neodymium hydroxide in hydrochloric acid with the concentration of 10mol/L, heating to 65 ℃, preserving heat for more than 30min, and obtaining a neodymium chloride solution after the neodymium hydroxide is completely dissolved, wherein the content of chloride in the neodymium chloride solution is more than 200 g/L;

s2, adding ammonium chloride into the neodymium chloride solution to obtain a primary mixed solution; the mass of the ammonium chloride is 2 times of that of the chloride in the neodymium chloride solution;

s3, heating the preliminary mixed solution until the free water is evaporated to dryness to obtain a viscous intermediate product;

s4, adding SOCl into the intermediate product₂，SOCl₂Submerging the intermediate product; stirring thoroughly, placing in a nitrogen-protected oven, heating to 80 deg.C, and keeping the temperature for 60 min;

s5, continuously heating to 200 ℃, then preserving the heat for 60min, and adding SOCl in the intermediate product₂Completely decomposing;

and S6, continuing to heat to 370 ℃, completely decomposing ammonium chloride in the intermediate product, and finally obtaining anhydrous neodymium chloride in a nitrogen protective atmosphere, wherein an oxygen analyzer is adopted to test the oxygen content of the anhydrous neodymium chloride to be 24ppm, and the water content is less than 10 ppm.

The reaction equation of the whole preparation process is as follows: NdCl₃·nH2O+SOCl₂+NH₄Cl＝NdCl₃+HCl+SO₂+NH₄Cl；

The invention firstly adds a large amount of NH into the neodymium chloride solution₄Cl is used for inhibiting and preventing neodymium chloride solution from being hydrolyzed into NdOCl during the process of heating to remove free water; then adding SOCl into the intermediate product₂By reaction H₂O+SOCl₂＝SO₂+2HCl gives two acid gases which can further inhibit the hydrolysis of neodymium chloride; then, by a heating operation, the excess SOCl is removed₂Decomposition to SO at 140 deg.C₂Chlorine gas,Disulfide dichloride, which is an acidic gas, further inhibits hydrolysis and oxidation of neodymium chloride; finally, heating is continued, and ammonium chloride is completely decomposed at 350 ℃, so that dry and clean anhydrous neodymium chloride is obtained.

Dissolving neodymium-containing oxide by hydrochloric acid, then sequentially adding an antioxidant and a dehydrating agent to perform the next reaction, and finally completely decomposing the antioxidant and the dehydrating agent in the mixed material by a drying box to finally obtain dry and clean anhydrous neodymium chloride; the whole preparation process does not need to adopt a high-pressure environment, the production cost of the anhydrous neodymium chloride is effectively reduced, the preparation process is easy, simple and quick to operate, and a brand-new way is developed for the preparation process of the anhydrous neodymium chloride.