2-DIMENSIONAL MODEL FOR SUBAERIAL DEPOSITION OF MINE TAILINGS SLURRY

Fine-grained mineral processing wastes are frequently disposed of in s lurry form by subaerial deposition after discharge from a pipeline. A delta is formed, the profile of which has a direct bearing on the volu me that is available for waste storage in a given containment structur e. The hydraulic sorting of particles down the delta profile dictates the engineering properties of the deposited wastes, which are of relev ance to future rehabilitation or reprocessing of the deposit. There is considerable merit in being able to predict the profile and hydraulic sorting in advance. An earlier approach that was based on an empirica l river-transport model had a limited theoretical basis and was theref ore of limited utility. A new theory for this approach, based on engin eering hydraulics, is presented. It clarifies the relationship between hydraulic sorting and delta profiles, as well as the overall morpholo gy of deltas, for a wide range of fine-grained mineral processing wast es. The theory is consistent with data that were obtained from tailing s deltas at coal and platinum mines.