The fundamentals of ultrafine grinding in vibro-energy and annular ball mills

Abstract: The growing demand for ultrafine materials, the stringent quality requirements and the rising energy cost have prompted interests in the development and improvements of fine particles production techniques. The methods of producing fine particles are summarized in this thesis. The choice of a particular equipment or method is influenced by a number of factors among which are the end-use of the product, required product size distribution, the capital costs of equipment and ancillary, sensitivity of the material to heat and purity requirement. The characteristic parameters in some mechanical methods of grinding as typified by vibration and agitated mills were studied experimentally. Similarly, the role of surfactants on the grinding behaviour and the sub-structural properties of the ground minerals using the afore-mentioned mills were also investigated. The mass balance approach was also used to study the grinding principles of the annular ball mill. Numerical modelling of the mill product size distribution was therefore attempted using the determined parameters. A fairly good correlation was obtained between the experimental and computed products size distributions.