The paper presents the results of an experimental and theoretical study of the total transmissivity factor for a plane gas−dust flow seeded with solid metallic particles in dependence on the microstructure of the medium and weight concentration of particles. The means of desaggregation and transport of microparticles is found to have an appreciable effect on disperse composition of the gas−dust flow. A change in the disperse composition effects its attenuation and scattering coefficients and, hence, the effectiveness of attenuation of the radiation fluxes. A good agreement between the experimental data on the gas−dust layer transmissivity factor as a function of the particles concentration and the theoretically predicted results testifies to the validity of the suggested physical model and the calculation technique, so much as of the assumption on the sphericity of particles in the theoretical analysis of radiation attenuation in anisotropicaliy scattering gas−dust media.