Neodymium Carbonate_Industrial Additive

Neodymium carbonate [Background and Overview]

Rare earth elements include 15 types of lanthanide elements and 17 types of scandium and yttrium. my country is the country with the largest rare earth reserves in the world, distributed in 18 provinces and cities. 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.

The chemical formula of neodymium carbonate is C₃H₂Nd₂O₁₀. Molecular weight 486.52200. Among light rare earth carbonates, zinc carbonate is the most difficult to crystallize. The amorphous precipitate formed by the reaction of hydrogen carbonate and soluble gold salt is difficult to achieve crystallization transformation in a short time. Therefore, the main problems in the industrial production of zinc carbonate are difficulty in crystallization, long production cycle, and unsatisfactory product physical properties such as particle size and specific gravity. To solve these problems, it is necessary to have a comprehensive understanding and mastery of the crystallization properties of zinc carbonate.

Neodymium carbonate [production process]

1. Solvent extraction method: The raw material is the rare earth stripping solution after extracting lanthanum with dimethylheptyl methylphosphonate (P350), and concentrates it into a solution containing total RexOy150/L and fluorophenylboric acid FINO30.3 mol/L. Rare earth solution. In the first step, neodymium and samarium are grouped using bis(2-ethylhexyl)phosphoric acid (P2O4)-kerosene solution. In the second step, neodymium is extracted with trialkylmethylamine chloride (N263)-kerosene solution to obtain an acidic neodymium nitrate solution. Neutralize with ammonia water, add ammonium bicarbonate at a lower temperature to precipitate neodymium carbonate, filter, wash, centrifuge and dry to obtain the product.

2. Use ammonium bicarbonate as a precipitant to prepare neodymium carbonate: Agricultural ammonium bicarbonate is used as a rare earth precipitant to produce crystalline neodymium carbonate that is easy to settle and filter. This neodymium carbonate is burned into neodymium oxide. The quality indicators are better than the national standards for neodymium oxide products. The reaction process is as follows:

Neodymium carbonate [Application]

Neodymium carbonate can be used as a decolorizing agent and colorant for glass, and can also be used to prepare other nanomaterials. 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 it evenly in a mixer to obtain filler; wherein, the rare earth material includes 0.01~1.5 parts of lanthanum carbonate, 0.01~1.5 parts of cerium carbonate, 0.01~1.5 parts of praseodymium carbonate, and 0.01~1.5 parts of neodymium carbonate. 1.5 parts and 0.01~1.5 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 three, fill in theThe material and film material are mixed and dispersed according to the weight mixing ratio of 2.5:7.5, 3.8:6.2 or 4.8:5.2 to obtain the 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.

Neodymium carbonate [Reference]

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

[2] Leng Zhongyi, Ma Ying. Preparation of neodymium carbonate and neodymium oxide using ammonium bicarbonate as precipitant[J]. Rare Earth, 2000, 21(6): 26-29.

[3] 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

[4] Zhang Jixi. A heat-absorbing energy-saving coating and its preparation method. CN201710930983.2, application date 2017-10-09