Abstract: The purpose of this work is to establish the theoretical
foundations for calculating and designing the sublimationcondensation
processes in chemical apparatuses which are intended
for production of ultrafine powders of crystalline and amorphous
materials with controlled fractional composition. Theoretic analysis
of the primary processes of nucleation and growth kinetics of the
clusters according to the degree of super-saturation and the
homogeneous or heterogeneous nature of nucleation has been carried
out. The engineering design procedures of desublimation processes
have been offered and tested for modification of the Claus process.