Carbon fibers loaded with potassium carbonate and with metallic copper were prepared by applying a blending method. Raw isotropic coal pitch was blended with KOH or CuBr2 and obtained mixtures were subjected to spinning. In this way KOH and copper salt-blended fiber with uniform distribution of potassium and copper were spun. The raw fibers were exposed to stabilization with a mixture Of CO2 and air or air only through heating to 330 degrees C and next to treatment with carbon dioxide or hydrogen at higher temperatures. Electron probe micro-analysis (EPMA) analyses showed presence of potassium carbonate or metallic copper predominantly in peripheral regions of the obtained fibers. Basing on the mechanisms of potassium and copper diffusion over the carbon volume, generalized method for the deposition of additives onto surface of carbon materials is proposed. (c) 2005 Elsevier B.V. All rights reserved.