Preparation and application of neodymium carbonate dihydrate_Industrial additives

Background and overview of preparation and application of neodymium carbonate dihydrate

Neodymium carbonate dihydrate can be used to prepare neodymium oxide (Nd₂O₃). Neodymium oxide (Nd₂O₃) is an important rare earth oxide product. In the past 10 years, neodymium oxide has been widely used in materials such as rare earth permanent magnets, lasers, glass, ceramics and superconductors. The domestic and foreign market demand has continued to increase, and the development prospects are broad. Generally, neodymium oxide (Nd₂O₃) is produced by burning high-purity neodymium carbonate dihydrate.

Preparation and application of neodymium carbonate dihydrate

A method for preparing neodymium carbonate, including the following steps, wherein the concentration of ammonium bicarbonate is 95g/L and the mass concentration of neodymium chloride is 0.36mol/L:

S1: Place neodymium chloride in the reaction tank, control the pH to 1.5, blow in CO₂, the volume ratio of the CO₂ to neodymium chloride The ratio is 5:1, filter to remove the filter residue;

S2: Add hydrochloric acid solution with pH=1 to the reaction tank. The volume ratio of neodymium chloride to hydrochloric acid is 4:1. After sufficient stirring, filter the residue to remove it;

S3: Slowly add ammonium bicarbonate to the reaction tank, and stir the liquid in the reaction tank while adding ammonium bicarbonate. The stirring speed is 50r/min, and the pH after adding ammonium bicarbonate is controlled to be 5;

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S4: Leave to stand at 30°C for 10 minutes;

S5: Filter the materials in the reaction tank and pass through an 80-mesh sieve; the filter residue obtained after filtration is crystalline neodymium carbonate, and the crystalline neodymium carbonate is washed twice with hot water. The temperature of the hot water is 40 ℃;

S6: Air-dry the washed crystalline neodymium carbonate at 20°C.

Preparation and application of neodymium carbonate dihydrate

CN2014 Mica 10158302.1 discloses a fireproof polyurethane foam coating and its preparation method. The polyurethane foam coating film contains water-based polyurethane resin, 40-60% neodymium carbonate dihydrate, modified palygorskite, 1-2% matting powder, and 0.4-0.6% leveling agent based on the mass of the water-based polyurethane resin. , 0.4~0.6% stripping aid, and the balance water. The modified palygorskite polycarbonate consists of palygorskite accounting for 3~9% of the quality of the water-based polyurethane resin and 7~13% of the palygorskite quality. Silane coupling agent is obtained by surface treatment. The polyurethane foam coating of the present invention contains water-based polyurethane resin, hydrated neodymium carbonate, modified palygorskite, matting powder, leveling agent, and stripping aid. Neodymium carbonate dihydrate is a flame retardant with excellent flame retardant properties, and modified palygorskite has good fire resistance. The synergistic use of the two can improve the fire resistance of polyurethane foam coatings. By optimizing the ratio of various additives and water-based polyurethane resin, the film has better waterproofness and breathability.

References

[1]CN201910275262.1 A method for preparing neodymium carbonate

[2]CN201410158302.1 A fire-proof polyurethane foam coating and its preparation method