阅读说明：本技术 一种氧化镧的生产工艺 (Production process of lanthanum oxide ) 是由 黄华勇 邱光怀 安恩法 秦文忠 陆梅 祝裕炜 王珂 涂长东 谢曜 胡彦 于 2018-07-31 设计创作，主要内容包括：本发明公开了一种氧化镧的生产工艺,包括以下步骤：(1)将氧化镧加入到酸性溶液中制备镧盐溶液；(2)将镧盐溶液加入到乙二醇、聚乙二醇600的混合溶液中,充分搅拌至溶液溶清后加入表面活性剂和NaBr,充分混合均匀；(3)将步骤(2)的混合液加热至60-90℃,并缓慢加入(NH<Sub>4</Sub>)<Sub>2</Sub>CO<Sub>3</Sub>溶液,匀速搅拌,加入(NH<Sub>4</Sub>)<Sub>2</Sub>CO<Sub>3</Sub>溶液过程中出现白色沉淀物,反应1-3h后过滤、干燥得到LaOHCO<Sub>3</Sub>粉末；(4)将LaOHCO<Sub>3</Sub>粉末在800-1000℃的马弗炉中焙烧2-8h,即得白色La<Sub>2</Sub>O<Sub>3</Sub>粉末。本发明发展了一种简单、低成本制备氧化镧的多元醇方法；以乙二醇和聚乙二醇600为溶剂,以聚乙烯吡咯烷酮为表面活性剂,用NaBr控制反应速率进行球形氧化镧的制备,制备的球形氧化镧分散性好,其尺寸可以控制在0.05-10μm范围内。(The invention discloses a production process of lanthanum oxide, which comprises the following steps: (1) adding lanthanum oxide into an acid solution to prepare a lanthanum salt solution; (2) adding a lanthanum salt solution into a mixed solution of ethylene glycol and polyethylene glycol 600, fully stirring until the solution is clear, adding a surfactant and NaBr, and fully and uniformly mixing; (3) heating the mixed solution in the step (2) to 60-90 ℃, and slowly adding (NH) 4 ) 2 CO 3 Stirring the solution at a constant speed, and adding (NH) 4 ) 2 CO 3 White precipitate appears in the solution process, and is filtered and dried after reacting for 1-3h to obtain LaOHCO 3 Powder; (4) adding LaOHCO to the mixture 3 The powder is roasted in a muffle furnace at the temperature of 800-1000 ℃ for 2-8h to obtain white La 2 O 3 And (3) powder. The invention develops a simple and low-cost method for preparing the lanthanum oxide polyol; glycol and polyethylene glycol 600 are used as solvents, polyvinylpyrrolidone is used as a surfactant, and NaBr is used for controlling the reaction rateThe prepared spherical lanthanum oxide has good dispersibility, and the size of the prepared spherical lanthanum oxide can be controlled within the range of 0.05-10 mu m.)

1. A production process of lanthanum oxide is characterized by comprising the following steps:

(1) adding lanthanum oxide into an acid solution to prepare a lanthanum salt solution;

(2) adding a lanthanum salt solution into a mixed solution of ethylene glycol and polyethylene glycol 600, fully stirring until the solution is clear, adding a surfactant and NaBr, and fully and uniformly mixing;

(3) heating the mixed solution in the step (2) to 60-90 ℃, and slowly adding (NH)₄)₂CO₃Stirring the solution at a constant speed, and adding (NH)₄)₂CO₃White precipitate appears in the solution process, and is filtered and dried after reacting for 1-3h to obtain LaOHCO₃Powder;

(4) adding LaOHCO to the mixture₃The powder is roasted in a muffle furnace at the temperature of 800-1000 ℃ for 2-8h to obtain white La₂O₃And (3) powder.

2. The lanthanum oxide production process according to claim 1, wherein the acidic solution in step (1) is nitric acidOr one of hydrochloric acid with concentration of 0.6-1.6mol/L and corresponding lanthanum salt of La (NO)₃)₃Or LaCl₃(ii) a The concentration of the lanthanum salt is 0.5-1.5 mol/L.

3. The process for producing lanthanum oxide according to claim 1, wherein the surfactant in step (2) is polyvinylpyrrolidone (Mw 130000).

4. The lanthanum oxide production process according to claim 1, wherein the volume ratio of the ethylene glycol to the polyethylene glycol 600 in the mixed solution of the ethylene glycol and the polyethylene glycol 600 in the step (2) is 1: 0.5-2.

5. The lanthanum oxide production process according to claim 1, wherein the final concentration of each component in the system of step (2) is as follows: polyvinylpyrrolidone: 0.01-0.1mol/L, NaBr: 0.005-0.1mol/L, lanthanum salt: 0.1-0.5 mol/L.

6. The process for producing lanthana as claimed in claim 1, wherein (NH) in the step (3)₄)₂CO₃The concentration of the solution is 0.5-1.5 mol/L; said (NH)₄)₂CO₃The addition amount of (A) is 1.1-1.3 times of the molar amount of the lanthanum salt.

7. The process for producing lanthana as claimed in claim 1, wherein said (NH) is added in step (3)₄)₂CO₃The stirring speed is controlled to be 60-150r/min when the solution is prepared; said (NH)₄)₂CO₃The addition time is controlled to be 1-1.5 h.

8. The production process of lanthanum oxide according to claim 1, comprising the following steps:

(1) lanthanum oxide was added to a 1.6mol/L nitric acid solution to prepare 1.5mol/L La (NO)₃)₃A solution;

(2) adding La (NO)₃)₃Adding the solution into a mixed solution of ethylene glycol and polyethylene glycol 600, fully stirring until the solution is clear, adding polyvinylpyrrolidone (Mw 130000) and NaBr solution, and fully and uniformly mixing; wherein the volume ratio of the ethylene glycol to the polyethylene glycol 600 is 1: 1; the final concentration of each component in the system is as follows: polyvinylpyrrolidone: 0.1mol/L, NaBr: 0.1mol/L, La (NO)₃)₃：0.5mol/L；

(3) Heating the mixed solution in the step (2) to 75 ℃, and slowly adding 1.5mol/L (NH)₄)₂CO₃Solution, (NH)₄)₂CO₃The addition time of (D) is controlled to be 1.5h, (NH)₄)₂CO₃Is La (NO)₃)₃1.2 times of the molar weight of (NH) was added₄)₂CO₃The stirring speed is controlled at 100r/min when the solution is prepared; adding (NH)₄)₂CO₃White precipitate appears in the solution process, and the LaOHCO is obtained by filtering and drying after 2 hours of reaction₃Powder;

(4) adding LaOHCO to the mixture₃Roasting the powder in a muffle furnace at 900 ℃ for 5 hours to obtain white spherical La₂O₃And (3) powder.

Technical Field

The invention relates to the field of production of rare earth oxides, in particular to a production process of lanthanum oxide.

Background

Lanthanum oxide is one of the important products in light rare earths. Slightly soluble in water and easily reacts with acid to form the corresponding salt. Easily reacts with carbon dioxide and water in the air to gradually become lanthanum carbonate. Nowadays, lanthanum oxide products with good physicochemical properties are widely applied in the fields of military industry, civil use and high technology. For example, the lanthanum optical glass is La₂O₃A high-grade optical glass of borate or borosilicate as a main component, having unique optical characteristics of high refraction and low dispersion; adding La into electronic ceramic₂O₃Then, the sintering property, compactness, fiber structure, phase composition and the like of the ceramic can be improved, and the application performance of the ceramic can be obviously improved; la₂O₃It can also be used for purifying automobile exhaust.

The invention patent CN 105948098B discloses a spherical lanthanum oxide, the average grain diameter of the spherical lanthanum oxide is 150nm-1.2 μm, the method has high stability of the prepared lanthanum oxide, but the size is not easy to control, the grain uniformity is low, and the reaction can be carried out at 160-240 ℃.

Disclosure of Invention

In view of the problems in the prior art, the invention aims to provide a process for producing lanthanum oxide with controllable size and uniform particles.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a production process of lanthanum oxide comprises the following steps:

(1) adding lanthanum oxide into an acid solution to prepare a lanthanum salt solution;

(2) adding a lanthanum salt solution into a mixed solution of ethylene glycol and polyethylene glycol 600, fully stirring until the solution is clear, adding a surfactant and NaBr, and fully and uniformly mixing;

(3) heating the mixed solution in the step (2) to 60-90 ℃, and slowly adding (NH)₄)₂CO₃Stirring the solution at a constant speed, and adding (NH)₄)₂CO₃White precipitate appears in the solution process, and is filtered and dried after reacting for 1-3h to obtain LaOHCO₃Powder;

(4) adding LaOHCO to the mixture₃The powder is roasted in a muffle furnace at the temperature of 800-1000 ℃ for 2-8h to obtain white La₂O₃And (3) powder.

Further, the acid solution in the step (1) is one of nitric acid or hydrochloric acid, the concentration is 0.6-1.6mol/L, and the corresponding lanthanum salt is La (NO)₃)₃Or LaCl₃(ii) a The concentration of the lanthanum salt is 0.5-1.5 mol/L.

Further, the surfactant in step (2) is polyvinylpyrrolidone (Mw 130000).

Further, the volume ratio of the ethylene glycol to the polyethylene glycol 600 in the mixed solution of the ethylene glycol and the polyethylene glycol 600 in the step (2) is 1: 0.5-2;

further, the final concentration of each component in the system in the step (2) is as follows: polyvinylpyrrolidone: 0.01-0.1mol/L, NaBr: 0.005-0.1mol/L, lanthanum salt: 0.1-0.5 mol/L.

Further, the (NH) in the step (3)₄)₂CO₃The concentration of the solution is 0.5-1.5 mol/L; said (NH)₄)₂CO₃The addition amount of (A) is 1.1-1.3 times of the molar amount of the lanthanum salt.

Further, the (NH) is added in the step (3)₄)₂CO₃The stirring speed is controlled to be 60-150r/min when the solution is prepared; said (NH)₄)₂CO₃The addition time of (A) is controlled to be 1-1.5 h.

Furthermore, the production process of the lanthanum oxide comprises the following steps:

(1) lanthanum oxide was added to a 1.6mol/L nitric acid solution to prepare 1.5mol/L La (NO)₃)₃A solution;

(2) adding La (NO)₃)₃Adding the solution into a mixed solution of ethylene glycol and polyethylene glycol 600, fully stirring until the solution is clear, adding polyvinylpyrrolidone (Mw 130000) and NaBr solution, and fully and uniformly mixing; wherein the volume ratio of the ethylene glycol to the polyethylene glycol 600 is 1: 1; the final concentration of each component in the system is as follows: polyvinylpyrrolidone: 0.1mol/L, NaBr: 0.1mol/L, La (NO)₃)₃：0.5mol/L；

(3) Heating the mixed solution in the step (2) to 75 ℃, and slowly adding 1.5mol/L (NH)₄)₂CO₃Solution, (NH)₄)₂CO₃The addition time of (D) is controlled to be 1.5h, (NH)₄)₂CO₃Is La (NO)₃)₃1.2 times of the molar weight of (NH) was added₄)₂CO₃The stirring speed is controlled at 100r/min when the solution is prepared; adding (NH)₄)₂CO₃White precipitate appears in the solution process, and the LaOHCO is obtained by filtering and drying after 2 hours of reaction₃Powder;

(4) adding LaOHCO to the mixture₃Roasting the powder in a muffle furnace at 900 ℃ for 5 hours to obtain white spherical La₂O₃And (3) powder.

The polyvinylpyrrolidone can be used as a modifier for controlling the appearance of lanthanum oxide, and the growth of certain faces of the crystal is prevented by controlling the concentration of the polyvinylpyrrolidone, so that the growth of other faces is promoted; on the other hand, it can be used as stabilizer for LaOHCO₃Disperse and prevent LaOHCO₃And (3) agglomeration.

Due to the adoption of the technical scheme, the invention has the beneficial effects that:

the invention develops a simple and low-cost method for preparing the lanthanum oxide polyol; the invention takes ethylene glycol and polyethylene glycol 600 as solvents, takes polyvinylpyrrolidone (Mw 130000) as a surfactant, and uses NaBr to control the reaction rate to prepare the spherical lanthanum oxide, and the prepared spherical lanthanum oxide has good dispersibility and the size can be controlled within the range of 0.05-10 mu m.

Detailed Description

The present invention will be further described with reference to examples, but the present invention is not limited to these examples.