ISBN 9783843925334

978-3-8439-2533-4, Reihe Ingenieurwissenschaften

Stefan Romeis
From single particle compression testing to chemical influences of the solvent on wet grinding

198 Seiten, Dissertation Universität Erlangen-Nürnberg (2015), Softcover, A5

Zusammenfassung / Abstract

Comminution in stirred media mills is a frequently applied top-down unit operation. However, the general understanding of the involved complex processes is rather limited; scale-up is still mainly stuck with the power draw and simple process models of only little physical meaning. One of the main factors which certainly hampers a deepened understanding is the lack of experimental work which deals directly with the mechanical response of submicron single particles to applied external stresses.

Within the framework of this thesis, the particle breakage of single submicron silica colloidal particles (Stöber Fink Bohn silica - SFB) and vitreous silica particles in the size range from 200 nm to 5 µm has been studied. The vitreous silica particles were derived by a heat treatment of the SFB silica. The strength and breakage behavior of the particles observed during the single particle compression experiments was suc-cessfully cor¬related to the internal particle structure. The size dependent breakage behavior of the particles was furthermore transferred to wet comminution in stirred media mills: the influence of the used solvent on the process could be investigated. Furthermore, an experimental characterization of acting stresses and stress numbers during processing was possible. Finally, the feasibility of the solvent as a prosperous parameter for product design in stirred media milling is exemplarily shown for the micronisation of 45S5 Bioglass®.