Performance characterization of water-only Cyclone for processing high ash Indian coal

Abstract

In this study semi-empirical performance models have been employed to characterize the performance of water-only cyclone on the basis of experimental data modelling for fine coal cleaning. Experiments have been conducted in the laboratory on a 100 mm water only cyclone. High ash coals used for the experiments belong to the Patherdih and Munidih colliery in the Eastern part of India. Separation based on specific gravity was studied on Patherdih sample whereas size classification analysis has been carried out on Munidih sample. Washability studies on Patherdih sample have been undertaken to determine the specific gravity of effective separation for a desired coal quality. The Mayer curve has been employed to plot float-and-sink analysis from which the Tromp distribution curve is constructed. A reduced efficiency curve has been generated based on specific gravity as well as size classification analysis. Attempts have been made to describe the reduced efficiency curve by employing Rosin-Rammler and Logistic distribution function to characterize the performance of the cyclone. A simplified approach has been proposed to estimate the performance model parameters. Experiments were conducted by varying the operating parameters like spigot diameter, feed inlet pressure and percentage solids in the feed to study the sensitivity of operating conditions. The effect of operating variables on the performance of the cyclone in terms of classification function has been investigated. A graphical user interface (GUI) based user friendly software (HYDROSIM) has been developed based on semi-empirical models for calculating the cut-size (d50) under various operating conditions.