Interaction between the components of a binary coal blend has been studied using X-ray examination of a coal charge with contrasting elements embedded in it. We were the first to study the influence of changes in the composition of coal blends on the process of displacement of the nonvolatile mass while being carbonised. It is shown that the macrostructure of the coal plastic layer changes under the influence of changes in the blend composition and so does the pressure distribution measured by the compensation method. Based on the comparison of experimental and theoretical curves for the displacement of the non-volatile mass, we estimated the effect of the interaction between the components of a blend on the process of formation of a solid carbonisation residue. (C) 2002 Elsevier Science B.V All rights reserved.