Abstract The metal evaporation process is a special case of a heterogeneous process that proceeds between the liquid and gaseous phase. The investigation of kinetics of this process is principal problem which is essential for the analyse of many high-temperature extractive metallurgical processes, especially the metal refinement process. In the process of a component evaporation from the liquid metal one can distinguish three basic stages: the mass transport of an evaporating component from the liquid phase volume to the interface surface; the component evaporation from an interface surface - the transition from a liquid to a gaseous phase, the mass transport of an evaporating component from an interface surface into a gaseous phase. With regard to the fact the in an evaporation process the mass transport proceeds from one volume to another it is necessary to determine the overall rate constant k the is dependent on the mass transport coefficient in the liquid and gaseous phase. In the paper the method of calculating the mass transport coefficient and the process of a component evaporation from the liquid metallic alloy has been described. The method has been used to determine experimental coefficients in the process of zinc evaporation from Cu-Zn alloys in different gaseous atmospheres.