The use of bulk composites, the physical and mechanical properties of which are specified by the regulation requirements of a particular production area, including nuclear and thermal energy, is constantly expanding. Obtaining high-quality composite mixtures from solid dispersed media is associated with a number of difficulties in preventing the influence of segregation and adhesion effects. This presents a number of challenges in choosing a method for mixing bulk components, a type of mixing elements, rational range of changes in the main parameters of the specified process, etc. Ensuring an effective mode of mixing bulk materials is possible in the devices with rarefied flows, in particular, using rotary devices. The design of these special-purpose apparatuses is associated with the mathematical modeling of this process as an appropriate theoretical basis. An analytical description of bulk materials mixing and the organization of rarefied flows in the volume of a rotary mixer is carried out using the stochastic approach in approximating the equilibrium representation of the states of energetically closed macrosystem of each component. An energy method was used to analyze the dependence of the energy characteristics of the process of mixing bulk components, which was performed using rotary devices, on the operational and structural parameters of this operation. The revealed analytical relationship between the energy characteristics of each rarefied flow of bulk materials and the parameters of the process under study allows predicting the degree of influence of a number of factors on the quality of the finished bulk mixture.