A computational model is developed to predict the hydrodynamic and heat transfer characteristics of dilute liquid-solid laminar upflows through a concentric annulus. The dilute slurry is treated as a single phase Newtonian fluid of locally variable physical and thermal properties. Available experimental data of radial solid density distributions in dilute water-feldspar annular upflows is used in the model. Various important characteristics of laminar slurry flows were successfully predicted. It was also shown mathematically that in the limiting case of zero average solid loading, the solution reduces to that of the single phase. The radial location of maximum slurry density in the annular gap was found to be an important factor in determining both the flow and heat transfer behavior of the present system; also, the higher heat transfer enhancement ratios were predicted at the lower slurry Reynolds numbers. (C) 2003 Elsevier Ltd. All rights reserved.