Abstract
The mill concerned consists of a shallow cylindrical container vibrating in a horizontal circular path and a disc-shaped grinding body whose thickness is slightly smaller than the depth of the container. In this mill the breakage of material is carried out mainly by compressive stresses caused through the friction between the grinding body and the wall of the container. In certain vibrating and frictional conditions the grinding body moves rotating along the wall of the container in the opposite to the driving direction. The product of the frictional force between the grinding body and the wall of the container and the relative displacement of the grinding body is considered to contribute to the grinding efficiency. That is, the work performed through the movement of the disc should be proportional to the product of the angular velocity of the disc and the third power of the disc radius. The authors introduced an expression to calculate the angular velocity of the disc as a function of vibrating and frictional conditions as well as the mill dimensions to be used. An optimum disc radius with regard to the best grinding efficiency has been also discussed but the slippage degree of the disc has been assumed to be independent on the disc radius.
A series of grinding tests with reference to the performance of grinding body has been undertaken using four discs with different radii, the driving unit and the container of a laboratory type disc-ring-vibration mill.
The results of the grinding tests on quartz as grinding material have verified essentially our view on the performance of grinding body, but some disagreement has been found at the largest size of the grinding body. And the cause of this disagreement has been also discussed.
