The rheological behaviour of concentrated mineral suspensions can be controlled by understanding and regulating the net particle-particle interaction force. This paper summarizes the experimental results from studies showing how the yield stress of concentrated aqueous suspensions of alumina, zirconia and kaolin can be controlled through regulation of pH and the addition of inorganic electrolytes, ionic surfactants and polyelectrolytes (polymers). The various kinds of inter-particle forces acting in aqueous suspensions of fine particles are reviewed and used to interpret the experimental results. (C) 2000 Elsevier Science B.V. All rights reserved.