The normal impact of an ultrafine spherical silica particle with radius R=0.6m on the plane surface substrate was simulated numerically by applying DEM. The variation of the coefficient of restitution for a wide range of impact velocities up to 30m/s was investigated. The interaction model comprising both elastic and elastic-plastic contact with short-range van der Waals attraction was applied to capture the entire approach-rebound path. The study aims to evaluate the influence of various dissipation mechanisms during elastic and elastic-plastic contact with adhesion, with emphasis is placed on the role of the prescribed absorbed energy during rebound. The above approach was implemented into the discrete element method code DEMMAT. The numerical results are compared with the available solutions and employed for reasonable explanation of the impact experiment conducted by Poppe, Blum, and Henning (2000a). It is shown that experimentally observed scattering of the coefficient of restitution may be enveloped by curves related to various dissipation mechanisms.