Investigations into Fine Grinding

Abstract

This paper presents four different studies from the French national research project that deal with the fine grinding of hydrargillite. These include pilot plant tests of dry grinding in an air jet mill and wet grinding in a stirred bead mill. Two other more fundamental studies are concerned with determining fragmentation schemes in fine grinding. The first investigation concerns theoretical predictions of breakage of complex agglomerate crystals such as hydrargillite, plus image-analysis-based methods of identifying different types of particle morphology. Finally, single-particle impact fragmentation is studied in a specially designed apparatus which allows observation of particle impacts on a target at up to 300 m/s. This has led to the identification of different regimes of breakage that affect complex crystals such as hydrargillite.