It has been found that the maximum efficiency of graphite hydrogenation by H-2 under high-energy impact milling action is provided by the presence of hydride-forming metals. This effect is due to activation of HZ through the formation and decomposition of metal hydrides. The hydrogenation of graphite was carried out under flow conditions. The kinetic parameters of the process were studied for a graphite - Zr system. Kinetic and XRD measurements showed that Hz sorption during the first 15 - 20 min of milling form a highly dispersed tetragonal ZrHX (x = 1.8 - 2) phase. The specific surface area of the graphite - Zr sample changed from 0.6 to similar to 58 m(2)/g. At this stage, the Zr metal content in the sample was small. The next stage can be characterized as a steady state for the sorption - desorption of hydrogen. The formation of CH4 stopped because of coating the Zr microcrystals by carbon. We found that concurrent decomposition of tetragonal ZrHX and sorption of H-2 by graphite followed the steady-state condition. Further mechanochemical treatment led to a "stratified" composition that contained phases of graphite, cubic ZrH2, tetragonal ZrH, and Zr with a hcp lattice partly distorted and disordered.