The research is the complex analysis of influence of highly heated roaster gas radiation and limiting surfaces on heat transfer picture at sulphuric pyrites burning. Experiments were carried out in natural conditions in gas-pipes of mighty fluidized bed furnaces of boiling layer and boilers-utilizers in the line of sulphuric pyrites burning, and in laboratory conditions. The analyses carried out have shown that the roaster gas radiation spector in natural conditions is not smooth. The absorbing ability of the dust aircurrent depends on the wave length of the falling radiation and on the dust concentration in the current .