Response surface method for modeling of fine coal beneficiation by Knelson concentrator

Abstract

ABSTRACT In this study, the −1 mm fine coal is treated in a laboratory Knelson concentrator. The influence of various parameters (e.g., feed rate, solid content, centrifugal force, and the fluidization water pressure) on the yield and ash content of clean coal are thoroughly investigated and estimated by statistical polynomial models obtained using the response surface method (RSM). A second order polynomial model is developed to predict the yield and ash content; the models have a correlation coefficient of 0.9902 for yield and of 0.9221 for ash content of clean coal. Three-dimensional plots are presented to show the effects of process variables and their interactions on the response variables. The results show that all the variables affect the yield and ash content of clean coal to some degree. However, the centrifugal force and fluidization water pressure are found to be the most significant factors. Additionally, a numerical optimization process was applied to the developed models to search the factor space for the best trade-offs to achieve the maximum yield and lower ash content in the range of the experimental data. Under optimized working conditions, good separation efficiency is obtained with probability error Ep of 0.09.