Cerium Carbonate_Industrial Additive

Cerium Carbonate [Background and Overview]

In recent years, research on the application of lanthanide reagents in organic synthesis has developed by leaps and bounds. Among them, it was found that many lanthanide reagents have obvious selective catalytic effects in the reactions of carbon-carbon bond formation; at the same time, many lanthanide reagents were also found to have excellent properties in the reactions of organic oxidation reactions and organic reduction reactions to convert functional groups. The agricultural use of rare earths is a scientific research achievement with Chinese characteristics obtained by our country’s scientific and technological workers after many years of hard work. It has now been vigorously promoted as an important measure to increase my country’s agricultural production. Rare earth carbonate is easily soluble in acid, forming corresponding salts and carbon dioxide, and can be easily used in the synthesis of various rare earth salts and complexes without introducing anionic impurities. For example, it can react with strong acids such as nitric acid, hydrochloric acid, nitric acid, perchloric acid, sulfuric acid, etc. to form water-soluble salts. It can react with phosphoric acid and hydrofluoric acid to transform into poorly soluble rare earth phosphates and fluorides. It can react with many organic acids to form corresponding rare earth organic compounds. Compounds, which depending on the solution value, can be soluble complex cations or complex anions, or precipitated neutral compounds with less solubility. On the other hand, rare earth carbonate can be decomposed into the corresponding oxides after calcination, which can be directly used in the preparation of many new rare earth materials. At present, my country’s annual output of rare earth carbonate is more than 10,000 tons, accounting for more than a quarter of all rare earth commodities, indicating that the industrial production and application of rare earth carbonate occupies a very important position in the development of the rare earth industry.

Cerium carbonate is an inorganic compound with a chemical formula of C₃Ce₂O₉, a molecular weight of 460, and a logP of -7.40530. PSA is 198.80000, boiling point 333.6ºC at 760 mmHg, flash point 169.8ºC. In the industrial production of rare earths, cerium carbonate is an intermediate raw material for preparing a variety of cerium products such as various cerium salts and cerium oxide. Picoline has a wide range of uses and is a relatively important light rare earth product. Hydrated cerium carbonate crystals have a lanthanite-type structure. Its SEM photos show that the basic shape of hydrated cerium carbonate crystals is flakes. The flakes are held together by weak interactions to form a petal-like shape. The structure is loose, so under the action of mechanical force It is easy to break down into small fragments. The total rare earth content of cerium carbonate currently produced routinely in industry is only 42-46% after drying, which limits the production efficiency of cerium carbonate.

Cerium Carbonate [Synthesis]

A kind of cerium carbonate that consumes less water and has stable quality. After centrifugal spin-drying, the total rare earth content of the produced cerium carbonate can reach 72% to 74%. It is a simple one-step process to prepare high rare earth content cerium carbonate. process method. The following technical solution is adopted: Use a one-step method to prepare high rare earth total cerium carbonate, that is, heat the cerium material liquid with a mass concentration of CeO₂40~90g/L to 95℃-105℃, and add it under constant stirring Ammonium bicarbonate precipitates cerium carbonate. The amount of ammonium bicarbonate added is such that the pH value of the material liquid is finally adjusted to 6.3~6.5. The addition speed is suitable so that the material liquid does not bubble up. The resulting precipitate is centrifuged and dried. High total rare earth content of cerium carbonate is obtained. The cerium material liquid is at least one of a cerium chloride aqueous solution, a cerium sulfate aqueous solution or a cerium nitrate aqueous solution. The ammonium bicarbonate added in the present invention is solid or ammonium bicarbonate aqueous solution.

Cerium carbonate [Application]

Cerium carboxypropyl carbonate can be used to prepare cerium oxide, cerium dioxide and other nanomaterials. The applications and examples are as follows:

1. An anti-glare purple glass that strongly absorbs ultraviolet rays and the yellow part of visible light. Based on the composition of ordinary soda-lime-silica float glass, it includes the following raw material weight percentage components: silicon oxide 72~82%, sodium oxide 6~15%, calcium oxide 4~13%, magnesium oxide 2~8%, Aluminum oxide 0~3%, iron oxide 0.05~0.3%, cerium carbonate 0.1~3%, neodymium carbonate 0.4~1.2%, manganese dioxide 0.5~3%. This 4mm thick glass has a visible light transmittance of more than 80%, an ultraviolet transmittance of less than 15%, and a transmittance of 568~590nm wavelength of less than 15%.

2. A heat-absorbing energy-saving coating, characterized by being mixed with fillers and film-forming materials. The fillers are mixed with the following parts by weight of raw materials: 20 to 35 parts of silica, 8 parts of alumina ~20 parts, titanium oxide 4~10 parts, zirconium oxide 4~10 parts, zinc oxide 1~5 parts, magnesium oxide 1~5 parts, silicon carbide 0.8~5 parts, yttrium oxide 0.02~0.5 parts, chromium trioxide 0.01 to 1.5 parts, kaolin 0.01 to 1.5 parts, rare earth materials 0.01 to 1.5 parts, carbon black 0.8 to 5 parts, the particle size of each raw material is 1 to 5 μm; wherein, the rare earth materials include 0.01 to 1.5 parts of lanthanum carbonate, carbonic acid 0.01-1.5 parts of cerium, 0.01-1.5 parts of praseodymium carbonate, 0.01-1.5 parts of neodymium carbonate and 0.01-1.5 parts of promethium nitrate; the film-forming material is sodium potassium carbonate; the sodium potassium carbonate is the same weight of potassium carbonate and carbonate Sodium is mixed; the weight mixing ratio of the filler and film-forming material is 2.5:7.5, 3.8:6.2 or 4.8:5.2. Further, a method for preparing heat-absorbing energy-saving coating is characterized by including the following steps:

Step 1, preparation of fillers, first weigh 20 to 35 parts of silica, 8 to 20 parts of alumina, 4 to 10 parts of titanium oxide, 4 to 10 parts of zirconium oxide, and 1 part of zinc oxide by weight. ~5 parts, magnesium oxide 1~5 parts, silicon carbide 0.8~5 parts, yttrium oxide 0.02~0.5 parts, chromium trioxide 0.01~1.5 parts, kaolin 0.01~1.5 parts, rare earth materials 0.01~1.5 parts, carbon black 0.8 ~5 parts, and then mix them evenly in a mixer to obtainMaterials; wherein, the rare earth materials include 0.01 to 1.5 parts of lanthanum carbonate, 0.01 to 1.5 parts of cerium carbonate, 0.01 to 1.5 parts of praseodymium carbonate, 0.01 to 1.5 parts of neodymium carbonate, and 0.01 to 1.5 parts of promethium nitrate;

Step 2: Preparation of film-forming material. The film-forming material is sodium potassium carbonate. First, weigh potassium carbonate and sodium carbonate in parts by weight, and then mix them evenly to obtain the film-forming material; the carbonic acid Potassium sodium is a mixture of potassium carbonate and sodium carbonate of the same weight;

Step 3: Mix and disperse the filler and membrane material in a weight ratio of 2.5:7.5, 3.8:6.2 or 4.8:5.2 to obtain a mixture;

Step 4: ball-mill the mixture for 6 to 8 hours, and then pass it through a screen to obtain the finished product. The mesh size of the screen is 1 to 5 μm.

3. Preparation of ultrafine cerium oxide: Using hydrated cerium carbonate as the precursor, ultrafine cerium oxide with a median particle size less than 3 μm was prepared by direct ball milling and calcination. The obtained products all have a cubic fluorite structure. As the calcination temperature increases, the particle size of the product shows a downward trend, the particle size distribution becomes narrower and narrower, and the crystallinity increases. However, the polishing capabilities of three different glasses all show maximum values ​​between 900°C and 1000°C. Therefore, it is believed that the removal rate of glass surface substances during the polishing process is greatly affected by the polishing powder size, crystallinity and surface activity.

Cerium carbonate [Reference]

[1] Huang Ting. Research on the crystallization and related technologies of yttrium carbonate and neodymium carbonate[D]. Nanchang University, 2005.

[2] Zhou Xuezhen, Cheng Changming, Hu Jiandong, et al. Preparation of ultrafine cerium oxide and its polishing properties using cerium carbonate as precursor [J]. Rare Earth, 2006, 27(1): 1-3.

[3] Chen Jianli; Mou Baowei; Dai Yongjiu; Yao Longjun; Wang Yongli; Peng Jing; Sarula; Li He; Liu Lei; Zhao Jun; .2, application date 2012-04-24

[4] Li Mei: Liu Zhaogang: Zhang Xiaowei: Hu Yanhong: Wang Mitang: Zhang Yongqiang. Anti-glare purple glass with strong ultraviolet absorption. CN200910258727.9, application date 2009-12-11

[5] Zhang Jixi. A heat-absorbing energy-saving coating and its preparation method. CN201710930983.2, application date 2017-10-0