The process of hydraulic transport through pipelines, worldwide well known for the transport of fine-grain solids is also being used to a greater extent in mining for the handling of primarily coarse-grain solid - water mixtures for the removal of, for instance - coal and waste mixtures after coal winning using hydraulic monitors, tailings for backfilling underground and washer tailings and flotation waste to the dump._x000D_
A large-scale test unit was taken into service at the Bergbauforschung GmbH (Mining Research Company) in Essen-Kray, GFR, to further improve this technology. The unit was planned and built by Krupp Industrie- und Stahlbau of Duisburg in cooperation with Bergbauforschung GmbH._x000D_
The paper deals in detail with the demands made on this test unit and the technical results obtained on it and with the planned experimental research work.