Determination of saltation velocity is one of the key design parameters in pneumatic conveying systems. The aim of this work is to study the mechanism of saltation. Experimental results of measurements of saltation velocity in wind tunnel with very dilute flow are presented. Experiments were carried out with alumina spheres, glass beads, metal balls, sand, potassium sulphate and potash. The relationship between saltation velocity and the maximum conveying length (saltation length) is shown. The boundary saltation velocity was defined as the saltation velocity at which particulate solids can be conveyed for significant (long) distances. The influence of the feeding method (forced or gravitational feeding) and conditions on saltation velocity and length was investigated. (C) 2003 Elsevier B.V. All rights reserved.