Electrochemical production of graphite salts by intercalation of pure sulfuric acid has been performed using a three-dimensional packed bed of graphite particles percolated by the electrolyte. The first stage compound of graphite bisulfate in which all the layers are intercalated (Cl. HSO, 2.5 H2S04) was detected by the colour change to blue and X-ray diffractometry. The influence of the most important parameters (operating intensity, packed bed height, electrolyte percolation, type of graphite particles and electrode potential) has been deduced from experimental results, which show that formation of the first stage compound occurs first at the top of the bed and moves progressively downwards. A modelization allows to determine first the reaction rate, which appears to bc constant during operation, and second an electrochemical kinetics law of intercalation. NOMENCLATURE interfacial specific electrode area defined in (6) = 4, -f$,, local particlesolution potential Faraday's constant packed bed height current intensity = I/S current density defined in (7) initial current intensity mass of graphite particles in the bed mass of graphite particles remaining active mass of graphite particles having reacted active electrode surface time induction time distance measured from the anodic current feeders reaction front: distance measured from the top of the bed Faradaic yield particle and solution potentials