Dense Medium Cyclone

This paper outlines the importance of dense medium cyc-lones in coal cleaning along with process optimisation through modelling. Dense medium cyclone was developed by Dutch State Mines in 1940s and since inception it has gained tremendous importance for coal cleaning application around the globe. Indian coal preparation plants largely
rely on washing at intermediate size (i.e. -13+0. 5 mm) because of drift nature of our coals as well as the ease of material handling at this size. Dense medium cyclones are widely used in Indian washeries due to their ability to handle larger tonnage and ease of operation.

Dense medium cyclone operation is very sensitive to the variation of process and design variables. The author and his co workers have developed simple empirical models to predict and optimise the performance of dense medium cyclone. The usage of these models developed at the labo-ratory level to improve the plant performance has been discussed. Such optimisation works undertaken by the author resulted in 3-5% increase in yield of clean coal from dense medium cyclone circuits at the same ash level.