阅读说明：本技术 一种低氯氧化镥的制备方法 (Preparation method of low-chlorine lutetium oxide ) 是由 农潇 潘务霞 莫国荣 韦世强 张亮玖 黄新将 庄辉 马宗云 况涛 羊多彦 潘畅 于 2019-12-27 设计创作，主要内容包括：本发明公开了一种低氯氧化镥的制备方法,其包括如下步骤：(1)将氯化镥料液与草酸溶液进行反应,反应温度控制在60℃,进料完成后在60℃下陈化2h,然后过滤得到沉淀A；(2)将沉淀A高温灼烧、冷却,再加入浓硝酸溶解,然后再用高纯水稀释得到浓度为0.5mol/L的硝酸镥溶液；(3)将硝酸镥溶液与草酸溶液进行反应,反应温度控制在60℃,然后静置澄清后,在60℃下陈化30min后趁热过滤得到沉淀,再用60℃的高纯水洗涤沉淀1～2次得到草酸镥沉淀；(4)将草酸镥沉淀烘干、微波加热至800℃,保温1～2h,自然冷却到室温,即可得到低氯的氧化镥。本发明降低氧化镥中氯离子的含量,制备得到高纯度、低氯的氧化镥。(The invention discloses a preparation method of low-chlorine lutetium oxide, which comprises the following steps: (1) reacting lutetium chloride feed liquid with oxalic acid solution, controlling the reaction temperature at 60 ℃, aging at 60 ℃ for 2h after feeding is finished, and then filtering to obtain precipitate A; (2) firing and cooling the precipitate A at high temperature, adding concentrated nitric acid for dissolving, and then diluting with high-purity water to obtain lutetium nitrate solution with the concentration of 0.5 mol/L; (3) reacting a lutetium nitrate solution with an oxalic acid solution, controlling the reaction temperature at 60 ℃, standing for clarification, aging at 60 ℃ for 30min, filtering while hot to obtain a precipitate, and washing the precipitate with high-purity water at 60 ℃ for 1-2 times to obtain a lutetium oxalate precipitate; (4) and (3) drying the lutetium oxalate precipitate, heating to 800 ℃ by microwave, preserving the heat for 1-2 h, and naturally cooling to room temperature to obtain the low-chlorine lutetium oxide. The method reduces the content of chloride ions in the lutetium oxide, and prepares the lutetium oxide with high purity and low chloride.)

1. A preparation method of low-chlorine lutetium oxide is characterized by comprising the following steps: the method comprises the following steps:

(1) placing high-purity water with the volume being 3-4 times of that of the lutetium chloride material liquid into a precipitation tank, heating to 60 ℃ under the stirring condition, then adding the lutetium chloride material liquid, starting to add the oxalic acid solution for reaction after 2min from the time of starting to add the lutetium chloride material liquid, controlling the reaction temperature to be 60 ℃, continuing to add the oxalic acid solution for 5-10 min when the lutetium chloride material liquid is completely added, then continuing to stir for 30-45 min at the constant temperature of 60 ℃, then stopping stirring, aging for 2h at 60 ℃, and then filtering to obtain a precipitate A;

(2) firing the precipitate A obtained in the step (1) at the constant temperature of 800 ℃ for 1-2 h, naturally cooling to room temperature, slowly adding concentrated nitric acid for dissolving, wherein the temperature in the dissolving process does not exceed 40 ℃, and then diluting with high-purity water to obtain lutetium nitrate solution with the concentration of 0.5 mol/L;

(3) placing high-purity water with the volume being 3-4 times of that of the lutetium nitrate solution into a new precipitation tank, heating to 65 ℃ under the stirring condition, then adding the lutetium nitrate solution, starting to add the oxalic acid solution for reaction after 2min from the time of starting to add the lutetium nitrate solution, controlling the reaction temperature to be 60 ℃, stopping adding the oxalic acid solution when the lutetium nitrate solution is completely added, continuing to stir for 25-30 min at the constant temperature of 60 ℃, standing for clarification, sampling a supernatant to analyze the lutetium content, aging for 30min at the temperature of 60 ℃ if the supernatant does not contain lutetium, filtering to obtain a precipitate when the precipitate is hot, washing the precipitate with high-purity water at the temperature of 60 ℃ for 1-2 times to obtain the lutetium oxalate precipitate; if the supernatant contains lutetium, adding oxalic acid solution at the original speed for 3-4 min under the condition of stirring and the temperature of 60 ℃, then stirring for reaction for 5min, standing for clarification, and sampling the supernatant for analyzing the lutetium content;

(4) and (4) drying the lutetium oxalate precipitate obtained in the step (3) at 105 ℃ for 30min, then heating to 800 ℃ by using microwaves, preserving heat for 1-2 h, and naturally cooling to room temperature to obtain the low-chlorine lutetium oxide.

2. The method of preparing lutetium oxychloride of claim 1, wherein: the concentration of the lutetium chloride in the lutetium chloride feed liquid is 1.50 mol/L.

3. The method of preparing lutetium oxychloride of claim 1, wherein: in the step (1), the lutetium chloride material liquid is added into a precipitation tank at a constant speed, and the adding time of the lutetium chloride material liquid is controlled to be 90-100 min; the adding speed of the oxalic acid solution is the same as that of the lutetium chloride feed liquid.

4. The method of preparing lutetium oxychloride of claim 1, wherein: the stirring speed in the step (1) is 120 r/min.

5. The method of preparing lutetium oxychloride of claim 1, wherein: the stirring speed in the step (3) is 120 r/min.

6. The method of preparing lutetium oxychloride of claim 1, wherein: adding the lutetium nitrate solution into a new precipitation tank at a constant speed in the step (3), wherein the adding time of the lutetium nitrate solution is controlled to be 90-100 min; the adding speed of the oxalic acid solution is the same as that of the lutetium nitrate solution.

7. The method of preparing lutetium oxychloride of claim 1, wherein: the concentration of the oxalic acid solution is 100 g/L.

8. The method of preparing lutetium oxychloride of claim 1, wherein: the power of the microwave in the step (4) is 50-60 kW.

9. The method of preparing lutetium oxychloride of claim 1, wherein: the high-purity water is the pure water with the conductivity less than or equal to 20 mu s/M and the resistivity more than or equal to 5M omega cm after the raw water is treated.

Technical Field

The invention belongs to the technical field of rare earth material preparation, and particularly relates to a preparation method of low-chlorine lutetium oxide.

Background

Rare earth is a strategic element recognized in the world in the 21 st century, plays a key role in the field of high-technology functional materials such as magnetism, light, electricity and the like, high-purity rare earth oxide powder is an important raw material for preparing and synthesizing various novel functional materials, and along with the continuous expansion of the application field of rare earth oxide, the full reflection of the intrinsic property of the rare earth element is more and more obviously related to the performance index of the material, and the requirement on the index is higher and higher. For example, lutetium oxide can be used for neodymium iron boron permanent magnet materials, chemical additives, electronic industry, scientific research and the like, and the purity requirement of lutetium oxide is 99.99%. The existing method for preparing lutetium oxide mainly comprises the following steps: precipitation method, combustion method. The precipitation method usually uses inorganic amine precipitants such as ammonia water, ammonium bicarbonate and the like, and the inorganic amine precipitants need to be slowly added, so that the process is complex; the combustion method has high raw material cost and higher equipment requirement. The preparation process is that lutetium chloride and oxalic acid are directly added into a precipitation tank for reaction, the amount of filtered washing water is large, the content of chloride ions in the burnt lutetium oxide is large and is more than 150ppm, the purity and the using effect of the lutetium oxide are affected, the standard requirements of high-purity products cannot be met, the using effect of lutetium oxide products is affected, and the technical problem which needs to be solved is to adapt to market demands and prepare high-purity low-lutetium oxychloride.

Disclosure of Invention

Aiming at the defects, the invention discloses a preparation method of low-chlorine lutetium oxide, which is used for reducing the content of chloride ions in lutetium oxide and preparing high-purity low-chlorine lutetium oxide.

The invention is realized by adopting the following technical scheme:

a preparation method of lutetium oxychloride comprises the following steps:

(1) placing high-purity water with the volume being 3-4 times of that of the lutetium chloride material liquid into a precipitation tank, heating to 60 ℃ under the stirring condition, then adding the lutetium chloride material liquid, starting to add the oxalic acid solution for reaction after 2min from the time of starting to add the lutetium chloride material liquid, controlling the reaction temperature to be 60 ℃, continuing to add the oxalic acid solution for 5-10 min when the lutetium chloride material liquid is completely added, then continuing to stir for 30-45 min at the constant temperature of 60 ℃, then stopping stirring, aging for 2h at 60 ℃, and then filtering to obtain a precipitate A;

(2) firing the precipitate A obtained in the step (1) at the constant temperature of 800 ℃ for 1-2 h, naturally cooling to room temperature, slowly adding concentrated nitric acid for dissolving, wherein the temperature in the dissolving process does not exceed 40 ℃, and then diluting with high-purity water to obtain lutetium nitrate solution with the concentration of 0.5 mol/L;

(3) placing high-purity water with the volume being 3-4 times of that of the lutetium nitrate solution into a new precipitation tank, heating to 65 ℃ under the stirring condition, then adding the lutetium nitrate solution, starting to add the oxalic acid solution for reaction after 2min from the time of starting to add the lutetium nitrate solution, controlling the reaction temperature to be 60 ℃, stopping adding the oxalic acid solution when the lutetium nitrate solution is completely added, continuing to stir for 25-30 min at the constant temperature of 60 ℃, standing for clarification, sampling a supernatant to analyze the lutetium content, aging for 30min at the temperature of 60 ℃ if the supernatant does not contain lutetium, filtering to obtain a precipitate when the precipitate is hot, washing the precipitate with high-purity water at the temperature of 60 ℃ for 1-2 times to obtain the lutetium oxalate precipitate; if the supernatant contains lutetium, adding oxalic acid solution at the original speed for 3-4 min under the condition of stirring and the temperature of 60 ℃, then stirring for reaction for 5min, standing for clarification, and sampling the supernatant for analyzing the lutetium content;

(4) and (4) drying the lutetium oxalate precipitate obtained in the step (3) at 105 ℃ for 30min, then heating to 800 ℃ by using microwaves, preserving heat for 1-2 h, and naturally cooling to room temperature to obtain the low-chlorine lutetium oxide.

Further, the concentration of the lutetium chloride in the lutetium chloride feed liquid is 1.50 mol/L.

Further, in the step (1), the lutetium chloride solution is added into the precipitation tank at a constant speed, and the adding time of the lutetium chloride solution is controlled to be 90-100 min; the adding speed of the oxalic acid solution is the same as that of the lutetium chloride feed liquid.

Further, the stirring speed in the step (1) is 120 r/min.

Further, the stirring speed in the step (3) is 120 r/min.

Further, the lutetium nitrate solution in the step (3) is added into a new precipitation tank at a constant speed, and the adding time of the lutetium nitrate solution is controlled to be 90-100 min; the adding speed of the oxalic acid solution is the same as that of the lutetium nitrate solution.

Further, the concentration of the oxalic acid solution is 100 g/L.

Further, the power of the microwave in the step (4) is 50-60 kW.

Furthermore, the high-purity water is the pure water with the conductivity less than or equal to 20 mu s/M and the resistivity more than or equal to 5M omega cm after the raw water is treated.

The main chemical reactions taking place in the present invention are as follows:

(1) primary precipitation: 2LuCl₃+3 H₂C₂O₄+nH₂O→Lu₂(C₂O₄)₃·nH₂O↓+6HCl

(2) Primary burning decomposition: 2Lu (C)₂O₄)₃·nH₂O+3O₂→Lu₂O₃+12CO₂↑+2nH₂O

(3) Dissolving with nitric acid: lu (Lu)₂O₃+6HNO₃→2Lu(NO₃)₃+3H₂O

(4) Secondary precipitation: 2Lu (NO)₃)₃+3H₂C₂O₄+nH₂O→Lu₂(C₂O₄)₃·nH₂O↓+6HNO₃

(5) Secondary burning decomposition: 2Lu (C)₂O₄)₃·nH₂O+3O₂→Lu₂O₃+12CO₂↑+2nH₂O

Compared with the prior art, the technical scheme has the following beneficial effects:

1. the existing lutetium oxide preparation method is to directly add lutetium chloride and oxalic acid into a precipitation tank for reaction, the content of chloride ions in the burnt lutetium oxide is more than 150ppm and can not reach the standard requirement of products, the method adopts a two-step precipitation method for precipitation, the content of the chloride ions in the burnt lutetium oxide is less than 20ppm, other impurities such as chlorine and the like are relatively reduced, the purity reaches more than 99.999 percent, and the standard requirement of the products is met.

2. The method comprises the steps of directly mixing lutetium chloride feed liquid and oxalic acid for reaction and precipitation, drying and firing to obtain a primary lutetium oxide product with high chlorine content, dissolving the primary lutetium oxide product by nitric acid, and then precipitating by oxalic acid again, wherein the secondary precipitation adopts nitric acid as a reaction medium, so that chlorine ions are prevented from being brought into the precipitation, and the problem that a large amount of chlorine ions entering the precipitation cannot be burned and volatilized to remain in the lutetium oxide product is solved.

3. The invention respectively controls the adding time of the lutetium chloride feed liquid and the lutetium nitrate solution, so that the lutetium chloride feed liquid and the lutetium nitrate solution can correspondingly react with the oxalic acid solution at a reasonable speed, and precipitates with uniform granularity are obtained; because the too fast particle dispersibility that generates of feed rate is poor, easily the reunion, form the flocculent precipitate, the particle diameter of granule is inhomogeneous moreover, and feed rate is too slow can make the particle that generates low, the nucleation is fast in the supersaturation degree of solution, the particle diameter of granule is big, and the settling time is long, reduces production efficiency, increases the production energy consumption.

3. The method of the invention also adopts microwave heating to heat the lutetium oxalate precipitate, thus accelerating the decomposition of lutetium oxalate, causing the lutetium oxalate precipitate to be heated uniformly, causing impurities to volatilize quickly, and generating lutetium oxide products with high purity and small grain size.

4. The method is simple, short in period, high in production efficiency and beneficial to large-scale production.

Detailed Description

The invention is further illustrated by the following examples, which are not to be construed as limiting the invention thereto. The specific experimental conditions and methods not indicated in the following examples are generally conventional means well known to those skilled in the art.