Abstract: A gravity sedimentation process for the treatment of a slurry in a thickener to separate a solid from a liquid, the thickener having, at steady-state, a hindered settling zone and a compression zone, the process including the application of an effective amount of ultrasonic energy to the slurry in a transition zone within the hindered settling zone.

Abstract: The present invention provides a method of analysis which couples principle component analysis (PCA) with ToF-SIMS for obtaining surface chemical information from minerals. Statistical methods, based on the monolayer-sensitive time of flight secondary ion mass spectrometry (ToF-SIMS) technique, combined with principal component analysis (PCA) identifies combinations of factors strongly correlated (positively or negatively) in images or spectra from sets of data. In images, PCA selects these correlations from the mass spectra recorded at each of 256×256 pixels in a selected area of particles. In the image mode, PCA provides a much better method of selecting particles by mineral phase with clearer definition of particle boundaries due to multi-variable recognition.