The action of lime in promoting pipeline flow of tailing slurries

CIM Bulletin, Vol. 78, No. 880, 1985

J.R. HOFFERT and G.W. POLING, Department of Mining and Mineral Process Engineering, The University of British Columbia, Vancouver, British Columbia

A common practice in preventing gravity-fed tailing pipeline from plugging due to sanding is to add lime at relatively high dosage rates. The lime affects the rheology of the slurry "vehicle" which transports the coarser particles in a heterogeneous flow-regime. This paper describes a study of the effect of lime on the critical deposition velocities and friction head losses of Highmont Mining Company's mill tailing. Testwork using an extrusion viscometer was related to the surface chemistry changes brought about by the high lime additions. Lime additions which typically increased the tailing pH from 8.4 to 11.5 reduced the critical deposition velocities from approximately 3.2 to 1.7 m/sec.
Mots Clés: Tailing slurries, Mineral processing, Lime, Pipelines, Concentrators, Mill Tailings, Critical deposition, Velocities, Rheology.