An Investigation of the Polythermal Diagram of the Ternary System H2O–(NH4)2HPO4–(NH4)2SO4 between 0 and 25°C

Isotherms at 0, 10, and 25°C of the H2O–(NH4)2HPO4–(NH4)2SO4 ternary system have been established by conductivity measurements in the considered temperature range (0–25°C). Tracing the polythermal diagram has allowed to determine the existence domains of the solid phases: (NH4) 2HPO4·2H2O, (NH4)2HPO4, and (NH4)2SO4.