Sedimentation and suspension flows: Historical perspective and some recentdevelopments

Sedimentation and suspension flows play an important role in modern technol ogy. This special issue joins nine recent contributions to the mathematics of these processes. The Guest Editors provide a concise account of the cont ributions to research in sedimentation and thickening that were made during the 20th century with a focus on the different steps of progress that were made in understanding batch sedimentation and continuous thickening proces ses in mineral processing. A major breakthrough was Kynch's kinematic sedim entation theory published in 1952. Mathematically, this theory gives rise t o a nonlinear first-order scalar conservation law for the local solids conc entration. Extensions of this theory to continuous sedimentation, flocculen t and polydisperse suspensions, vessels with varying cross-section, centrif uges and several space dimensions, as well as its current applications are reviewed.