Abstract: The present invention refers to a shaft packing, in particular for use in colloid mill, with a sliding and a counter ring, one of the rings is made of a hard material having a Vickers hardness of at least 1,000 kp/mm2 and the other is made of a soft material having a hardness of 100 Shores at the most. In particular the surfaces in contact with each other are cooled and lubricated by a liquid. In order to further increase the life of said packing, the counter ring is displaceable and adjustable from the outside without being dismantled and the sliding ring holder is provided with centrifugal blades for keeping the material to be milled and milling bodies away from the contact surfaces of said rings. The construction of said shaft packings allows its use in a horizontally arranged colloid mill, wherein the material being milled flows in the direction of the widening cone.

Abstract: An agitator or stirrer mill and especially a colloidal mill, having rotating grinding impellers in a vessel, the blades of such impellers being adjustable in their inclination relatively to a radial plane of the vessel and rotating axle respectively in order to adjust the stirring and agitating intensity. This may allow treatment of agents without the use of auxiliary milling particles such as balls in the mill. Further, the blades of the impellers are individually removable and readily exchangeable in order to replace worn impeller blades.