Optimization of surfactant-aided coarse coal dewatering process in a pilot-scale centrifuge

Abstract

Water is a scarce and critical resource for the mineral processing industries and the recycling of the water recovered from different unit operations is possibly the best way to ensure the continued operation of the plants throughout the year. Moreover, the reduction in the product moisture content reduces the cost of transportation and drastically reduces the handling problems. In the present work, the dewatering efficiency of the coarse coal (−13 + 0.5 mm) in a pilot-scale vibratory basket centrifuge was measured and enhanced using surfactants as the dewatering aids, followed by the optimization using statistical analysis. The experiments were conducted considering three variables, i.e. feed rate, feed moisture content and surfactant concentration, using a full factorial design of the experiments. Experimental results were analysed with the help of a statistical software package (Statistica). Regression equations were developed to show the effect of each parameter and their interactions on the residual moisture content. The statistical model developed for the dewatering of coarse coal, using the three variables, was tested and was found to predict the moisture content of product coal with an average error of 5%.