The often observed dramatic reduction of the milling efficiency of submicron grinding in stirred ball milk is explained with the onset of agglomeration leading to an equilibrium state between agglomeration, desagglomeration and breakage. It is theoretically shown that the electrostatic stabilisation mechanism offers a powerful tool to influence the agglomeration process and thus grinding in the submicron range. A stability factor W is calculated showing stable conditions under which the agglomeration process could be avoided in the mill. In addition, the grinding and agglomeration processes are modelled describing the observed grinding process. From these calculations guidelines for a proper control of submicron grinding can be deduced. Furthermore, experimental results of agglomeration experiments are in reasonable agreement with the theory.
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