An Introduction to Elutriation Testing

One of the many process tested at Core is elutriation.  This method of separating target minerals from gangue minerals takes advantage of the differences in size, shape and density of the minerals.

In the elutriator (shown), slurry is continually pumped to the midway point of the unit (to avoid short circuiting) and allowed to fall due to gravity. Water is simultaneously injected from the bottom at a set upwards velocity. Heavy or coarse minerals with a settling velocity higher than the velocity of the injection water will report to the underflow, whilst lighter or finer minerals with settling velocities lower than the water will be carried with the water to the overflow.

The water velocity is determined by a pump speed and can be easily changed to suit the separation requirement.

Core has used this equipment for a variety of testwork programs testing gold ores, Albion Process residues and rare earth flotation concentrates.