Monoammonium phosphate is also known as ammonium dihydrogen phosphate. Colorless transparent square crystal or white crystalline powder. Relative molecular mass 115.03. Relative density 1.803(19℃). Melting point 180°C. 190.5°C Decomposes, losing ammonia and water to produce a mixture of ammonium metaphosphate (NH4PO3) and phosphoric acid. Refractive index 1.479 and 1.525. insoluble in acetone, acetic acid, slightly soluble in ethanol, soluble in water, solubility in water: 22.6 at 0℃, 28.20 at 10℃, 35.5 at 20℃, 39.5 at 25℃, 43.9 at 30℃, 57.0 at 40℃, 82.5 at 60℃, 118.3 at 80℃, 173.2 at 100℃. concentration of pH=3.8~4.4 in 3% aqueous solution. stable in air. partially decomposed at 100℃. Piezoelectric properties, no strong dielectric properties. Transformed to rhombohedral crystal system at low temperature (-125°C).
In food as a buffer, dough conditioner, bulking agent, yeast nutrient, fermentation aid; fertilizer; sugar industry processing aids; fire retardant for wood, paper, fabric; pharmaceutical raw materials. Ammonium dihydrogen phosphate high nitrogen and phosphorus content, often used as a basic compound fertilizer in agricultural production, but the low utilization rate of conventional fertilizers is a common problem in agricultural production, the low utilization rate of fertilizers not only causes a waste of resources, and the use of nitrogen fertilizer in large quantities to the environment and human health hazards, at the same time, the phosphate fertilizer market situation is serious, the world oversupply of phosphate fertilizer, phosphate fertilizer industry is facing serious challenges to the survival and development. Ammonium dihydrogen phosphate as an important chemical raw material, looking for new application prospects, broaden the application areas of phosphorus resources, will bring unprecedented new opportunities for the development of phosphorus chemical enterprises.
At present, there are many studies on ammonium dihydrogen phosphate at home and abroad, but most of them are aimed at the production and development of basic phosphate fertilizers. As the competition in the world conventional phosphate fertilizer market becomes more and more intense, the study of ammonium dihydrogen phosphate slow release/controlled release fertilizer will be a popular research in the future. By studying the mechanism of slow/controlled release, preparing new slow/controlled release coating materials and improving the performance of slow/controlled release fertilizers will be the next focus of work. Meanwhile, the preparation of high purity ammonium dihydrogen phosphate such as food grade and battery grade, and the expansion of the application of ammonium dihydrogen phosphate in food additives and battery materials are also an important research direction in the future. In addition, phosphate rare earth metal doped glass has good optical properties, the development of phosphate optical glass and special glass materials will also have a broad prospect.
