CN114560489A - A kind of preparation method of nanometer cerium hydroxide powder - Google Patents

Abstract

The invention discloses a preparation method of nano-cerium hydroxide powder, comprising the following steps: (1) preparing a certain concentration of ceric nitrate or ceric ammonium nitrate solution, then preparing a certain concentration of ammonia solution, and adding a dispersant to the ammonia solution CTAB or PEG, add cerium solution to the ammonia solution at a temperature of 0 to 100 °C with stirring; (2) after adding, stir and heat to 80 °C to 100 °C, and wash the precipitate with deionized water; (3) put the precipitate in Vacuum drying at 0°C to 30°C for 1h to 6h to obtain nano cerium hydroxide powder. The nano-cerium hydroxide prepared by the invention has good dispersibility, and the primary particle size is 50nm-100nm.

Description

A kind of preparation method of nanometer cerium hydroxide powder

technical field

The invention relates to a preparation method of nanometer cerium hydroxide powder.

Background technique

Cerium is a rare earth element, which has the characteristics of ductility and soft texture, and is widely used in aviation, catalysis, laser, electronics, optics and other materials. Cerium oxide is a cheap and widely used light rare earth oxide. Nano cerium hydroxide is an important member of the rare earth material family. It has important applications in battery and other aspects. With the continuous development of materials science, nano-cerium hydroxide materials have been paid more and more attention.

The existing preparation method of cerium hydroxide, such as the "production method of cerium hydroxide" disclosed in the Chinese patent application with the application number CN92100744.2, produces easy-to-filter and easy-to-wash hydrogen through the preparation of rare earth carbonate and the addition of an oxidant. Cerium oxide precipitates. The method prepared by the method is conventional cerium hydroxide, which has a low oxidation rate and does not meet the nanometer requirements. The Chinese patent application with the application number of CN89103858.2 discloses the "Process Method for Producing Pure Cerium Hydroxide", the method uses the acidic aqueous solution of cerium as the feed liquid, potassium permanganate as the oxidant, and the carbonic acid of alkali or ammonium is added. After precipitation of cerium, acid is used to dissolve cerium hydroxide, sodium sulfite is added and sodium chloride or sodium sulfate is added to form sodium cerium sulfate double salt, and the alkali is converted into cerium hydroxide. The process method of the invention is complicated in process, and the cerium hydroxide particles are large, which does not meet the nanometer requirements. "Preparation method of cerium hydroxide" disclosed in Chinese patent application with application number CN200310110329.5, this method adds alkaline solution to cerium solution to generate Ce(OH) ₃ , and then adds oxidant to oxidize trivalent cerium to tetravalent Valence Ce. The present invention is a production method of common cerium hydroxide, which still has unoxidized trivalent cerium due to post-oxidation, and does not meet the nanometer requirements. The Chinese patent application with the application number of CN201310345572.9 discloses "a process for extracting high-purity soluble cerium hydroxide from fluorocarbon-cerium mixed rare earth carbonate", the invention uses mixed rare earth carbonate as raw material, dissolves with hydrochloric acid, and adds ammonia water after removing impurities After the reaction with hydrogen peroxide, boil, the precipitate is dissolved with hydrochloric acid to control the pH value, washed with acid and boiled to adjust the pH value. The process of the invention is complicated, and the impurity content in the product is high. Due to the strong oxidation of tetravalent cerium, the chloride radical will be oxidized to chlorine gas, which causes great environmental pollution and does not meet the nanometer requirements.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a preparation method of nano-cerium hydroxide powder with simple production process, less equipment investment, large process controllable range and simple operation.

The technical solution adopted by the present invention to solve the technical problem is: a preparation method of nano-cerium hydroxide powder, comprising the following steps: the technical problem to be solved by the present invention is to provide a simple production process, less equipment investment, and the process can be A preparation method of nano cerium hydroxide powder with wide control range and simple operation.

The technical scheme adopted by the present invention to solve the technical problem is: a preparation method of nano-cerium hydroxide powder, comprising the following steps:

A preparation method of nanometer cerium hydroxide powder, comprising the following steps:

(1) prepare a cerium solution, then prepare an ammonia solution, add a dispersant to the ammonia solution, and add the cerium solution to the ammonia solution under stirring at a temperature of 0 to 100°C;

(2) After adding the cerium solution, stir and heat to 80°C to 100°C, and precipitate to obtain a precipitate, and the precipitate is washed with deionized water to obtain a washed precipitate;

(3) vacuum drying the washed precipitate to obtain nano cerium hydroxide powder.

In a further improvement, in step (1), the cerium solution used is one or any mixture of ceric nitrate and ceric ammonium nitrate.

A further improvement, in step (1), the concentration of cerium ions in the cerium solution is controlled to be 10g/L～150g/L.

Further improvement, in step (1), the dispersing agent is one or more of PEG 4000 and CTAB, and the amount of the dispersing agent added is 0.1% to 0.5% of the mass of cerium ions

Further improvement, in step (1), the amount of ammonia water added is 1 to 1.05 times the theoretical amount, and the concentration is controlled at 5 g/L to 50 g/L, and the theoretical amount is according to the reaction equation 4Ce ⁴⁺ +4NH ₃ ·H ₂ O=Ce(OH) ₄ ↓+4NH ₄ ⁺ .

A further improvement, in step (2), the precipitation temperature is controlled at 0-100°C.

A further improvement, in step (3), the vacuum drying temperature is controlled at 0°C to 30°C.

A further improvement, in step (3), the vacuum drying time is controlled within 1h-6h.

Description of drawings

Fig. 1 is a kind of process flow diagram of the preparation method of nano cerium hydroxide powder of the present invention;

Fig. 2 is a thermogravimetric diagram of a preparation method of a nanometer cerium hydroxide powder of the present invention;

Fig. 3 is a kind of preparation method X-ray diffraction diagram of nano cerium hydroxide powder of the present invention;

4 is a scanning electron microscope image of the preparation method of the nano-cerium hydroxide powder of Example 1 of the present invention.

5 is a scanning electron microscope image of the preparation method of the nano-cerium hydroxide powder of Example 2 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the examples.

Example 1

Step as shown in Figure 1, a preparation method of nano cerium hydroxide powder, comprising the following steps:

(1) 800 mL of ceric nitrate solution with a concentration of 60 g/L was prepared, 484 mL of 40 g/L ammonia solution was taken, 0.24 g of CTAB dispersant was added to the ammonia solution, and under stirring at a constant temperature of 20 °C, the ceric nitrate solution was added dropwise. Add it to the ammonia solution containing the dispersant, and continue stirring for 30 min after the reaction is complete.

(2) The fully reacted cerium hydroxide was heated to 80°C, stirred at a constant temperature for 1 h, filtered, and the precipitate was washed with deionized water for 3 times and then dried to obtain a nano-cerium hydroxide precipitate. The thermogravimetric analysis is shown in Figure 2.

(3) The former cerium hydroxide precipitate was placed in a vacuum oven, and dried at a constant temperature of 20 °C for 4 hours to obtain nano-cerium hydroxide powder. The X-ray diffraction is shown in Figure 3, and the scanning electron microscope is shown in Figure 4.

Example 2

Step as shown in Figure 1, a preparation method of nano cerium hydroxide powder, comprising the following steps:

(1) Prepare 10L of ceric nitrate solution with a concentration of 20g/L, take 2.76L of 30g/L ammonia solution, add CTAB dispersant 0.4g and PEG 4000 dispersant 0.4g to the ammonia solution, and stir at a constant temperature of 80°C. , the cerium nitrate solution was added dropwise to the aqueous ammonia solution, and after the reaction was completed, stirring was continued for 1 h.

(2) The fully reacted cerium hydroxide is heated to 90° C., stirred at a constant temperature for 1.5 hours, filtered, and the precipitate is washed with deionized water for 3 times and then dried to obtain a nanometer cerium hydroxide precipitate.

(3) The precipitation of cerium hydroxide was placed in a vacuum oven, and dried at a constant temperature of 10 °C for 6 h to obtain nano-cerium hydroxide powder. The scanning electron microscope is shown in FIG. 5 .

Claims (8)

1. A preparation method of nano cerium hydroxide powder is characterized by comprising the following steps:

(1) preparing a cerium solution, then preparing an ammonia water solution, adding a dispersing agent into the ammonia water concentrated solution, and adding the cerium solution into the ammonia water solution under the condition of stirring at the temperature of 0-100 ℃;

(2) after the cerium solution is added, stirring and heating to 80-100 ℃, precipitating to obtain a precipitate, and washing the precipitate with deionized water to obtain a washed precipitate;

(3) and drying the washed precipitate in vacuum to obtain the nano cerium hydroxide powder.

2. The method for preparing nano cerium hydroxide powder according to claim 1, wherein in the step (1), the cerium solution is one or two of ceric nitrate and ammonium ceric nitrate.

3. The method according to claim 1, wherein in the step (1), the concentration of cerium ions in the cerium solution is controlled to be 10-150 g/L.

4. The method for preparing nano cerium hydroxide powder according to claim 1, 2 or 3, wherein in the step (1), the dispersant is one or more selected from PEG 4000 and CTAB, and the addition amount of the dispersant is 0.1-0.5% of the mass of cerium ions.

5. The method for preparing nano cerium hydroxide powder according to claim 1, 2 or 3, wherein in the step (1), the amount of ammonia added is 1 to 1.05 times of the theoretical amount, and the concentration is controlled to be 5 to 50g/L, wherein the theoretical amount is according to the reaction equation 4Ce⁴⁺+4NH₃·H₂O＝Ce(OH)₄↓+4NH₄ ⁺。

6. The method for preparing nano cerium hydroxide powder according to claim 1, 2 or 3, wherein in the step (2), the precipitation temperature is controlled to be 0-100 ℃.

7. The method for preparing nano cerium hydroxide powder according to claim 1, 2 or 3, wherein in the step (3), the vacuum drying temperature is controlled to be 0 ℃ to 30 ℃.

8. The method for preparing nano cerium hydroxide powder according to claim 1, 2 or 3, wherein in the step (3), the vacuum drying time is controlled to be 1-6 h.

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