Hold-up studies in a pilot scale continuous ball mill: dynamic variations due to changes in operating variables

In the past experimental studies on mill hold-up were done using tracers an d residence time distribution analysis (RTD). In one or two studies the ent ire content of the mill was weighed after the experimental run. Either as a result of inflexible experimental setup or difficulties in measuring hold- up in closed-circuit industrial mills via the RTD approach, the published c orrelation between hold-up measurements and mill feed rate disagree with ea ch other. In this study a carefully constructed pilot mill enabled hold-up measurements in real time while the mill was operating. Therefore, extremel y accurate hold-up data and transient hold-up data were obtained. In light of this data the correct trends in hold-up as a function of operating condi tions are established. Explanations for the observed trends are provided th rowing much light on anomalies on previously published data. (C) 1999 Elsev ier Science B.V. All rights reserved.