Experiments were carried out in the 18 km long, 600 mm diameter pipeline at the thermal power station complex at Tusimice in Czechoslovakia. This pipeline carries a pumped slurry of pulverised ash and slag to the final disposal lagoon. The soluble polymer, Separan AP-302, was injected into this pipeline as a possible means of increasing the solids transport rate to 2 Mm3per annum. Pressure gradients, velocities, solids concentration and polymer concentration were measured and gave encouraging results. Laboratory tests in small pipes with the same materials showed a high level of drag reduction and no adverse behaviour due to the solids loading.