An introduction to urea phosphate

Acid urea is a phosphoric acid salt formed by the reaction of urea and phosphoric acid under certain conditions; its chemical formula is CO(NH2)2·H3PO4, with a molecular weight of 158.07. It contains 17.73% nitrogen and 19.59% phosphorus (equivalent to 44.94% P2O5). Urea phosphate is a colorless and transparent prismatic crystal with a parallel layered structure; the layers are connected to each other by hydrogen bonds. It belongs to the orthorhombic crystal system, with a melting point of 117–117.5°C and a density of 1.74 g/cm3. The crystal is soluble in water and ethanol, but insoluble in ethers, toluene, carbon tetrachloride, etc. The aqueous solution is acidic, with a pH of 1.89 for a 1% solution. The solubility at 46°C is 202 g/L. The amino structure of urea phosphate determines that it has low thermal stability; it decomposes easily when heated, and the decomposition products vary depending on the temperature. As the temperature rises, its rate of thermal decomposition increases. Urea phosphate decomposes into urea and phosphoric acid when dissolved in water, releasing a small amount of carbon dioxide and ammonia. The melting point and viscosity of urea phosphate decrease significantly as the water content increases. Urea phosphate is a complex formed by the reaction of urea and phosphoric acid in equal molar amounts; the reaction equation is: CO(NH2)2 + H3PO4 = CO(NH2)2·H3PO4. The synthetic methods for urea phosphate include the wet phosphoric acid method, the thermal phosphoric acid method, and the polyphosphoric acid method.

　【Chinese Name】Urea Phosphate； Urea phosphate 【English name】urea phosphate 【Structure or molecular formula】 【Melting point (°C)] 117.3 【Toxicity LD50 (mg/kg)] It is considered a low-toxicity substance. 　　【Properties】 Colorless and transparent prismatic crystals. 　　【Solubility】 Easily soluble in water; the aqueous solution is acidic ； Insoluble in ethers, toluene, and carbon tetrachloride. 　　【Uses】 It is an excellent feed additive, as well as a high-concentration nitrogen-phosphorus compound fertilizer. It can also be used as a flame retardant, a treatment agent for metal surfaces, a nutrient for fermentation, a cleaning agent, and an auxiliary for purifying phosphoric acid. 　　【Preparation or Source】 Obtained by the reaction of wet phosphoric acid with urea solution ； It can also be obtained by the reaction of dilute phosphoric acid with urea. 　　【Tiande Brand Urea Phosphate】 Tiande Brand Urea Phosphate, Guizhou Tiande Chemical Co., Ltd., http://34927618.diytrade.com. Chemical formula: H3PO4•CO(NH2)2; Molecular weight: 158.06. Product standards: Q/62089823-7.3-2002, NY/T 917-2004. 　　Physical properties: White crystalline powder; melting point 117.3°C; soluble in water, with an acidic aqueous solution. 　　Effective content: 98%. 　　Technical specifications: P2O5>44%, P>19%, N>17%, As

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