The designing of slurry pipelines requires prediction of pipeline hydraulic performance. The preferable predictive tool is a model based on a physical description of slurry flow behavior in a pipeline. Various mechanisms that affect pipeline flow behavior of settling slurries with a Newtonian conveying liquid are described. Recent developments in measuring, understanding and modeling of the mechanisms are discussed. An implementation of recent research results to current versions of a predictive model for stratified flows of settling slurries (a two-layer model) is surveyed. (c) 2005 Elsevier B.V. All rights reserved.