尿素结晶介稳区宽度实验研究

Research on Metastable Zone Width of Urea Crystallization

以农用尿素为原料,研究了尿素结晶的热力学特性,分别考察了以水、溶媒A、溶媒B作为结晶溶媒的溶解度及介稳区宽度。结果表明,尿素在三种溶剂中的溶解度随温度升高而增大,介稳区宽度随温度升高而减小,介稳区宽度的次序为水>溶媒B>溶媒A。原料尿素的纯度提高,介稳区宽度变窄;添加晶种,介稳区宽度变窄。

The thermodynamic properties of urea crystallization were studied by using agricultural urea as raw material. The solubility and metastable zone width of urea at different temperatures in water, solvent A and solvent B were investigated respectively. Experimental results showed that with the increasing of temperature, the solubility increased while the metastable zone width became narrower. The relationship of metastable zone widths of urea in above three solvents was： water 〉 solvent B 〉 solvent A. With the improving of purity and seeds addiction, the metastable zone width of urea became narrower obviously.