ABSTRACT
The paper presents the use of hydraulic backfill in the Velenje Coal Mine and the development of some procedures and devices for optimizing the basic properties of backfill mixtures. The technical, economic and environmental aspects of the hydraulic transportation of thick backfill mixtures (pastes) may be estimated only if the rheological properties are previously determined. For this purpose we developed the ball-pull test device, the tube viscosimeter and the pressure leaching test (PLT) equipment. A brief outline of tests of plastic and leaching characteristics and the method for determining the pressure gradient required for the specific flow of a time-independent non-Newtonian backfill mixtures and its application in the Velenje Coal Mine will be also presented.
