Based on the current status of fertilizer industry in China, a new cleaning process of compound fertilizer by decomposing phosphate rock with urea-sulfuric acid (USC in brief) is proposed and a systematic theory study is performed. The principal results are as follow:
1. Basic data of the system, such as density, viscosity, enthalpy of solution of urea at different mole ratio in sulfuric acid, specific heat, melting point, phase transformation heat of urea-sulfuric acid are determined. It is found...