Separation of the coal-quartz mixture using tribo-electrostatic separator: Effect of surface pretreatment

Abstract

The present study illustrates the effect of physical (thermal) and chemical surface treatment on the separation of the coal-quartz synthetic mixture in a tribo-electrostatic separator. The work also reports the effect of applied voltage and splitter position on the tribo-electrostatic separation of surface treated and untreated samples. Different reagents used in chemical conditioning of the synthetic mixture are kerosene, acetic acid, acetone, ethanol, phenol, toluene, and aniline. The study establishes that both chemical and heat treatment improves the tribo-electrostatic separation efficiency of coal and quartz particles. The applied voltage and splitter position affect the product grade and yield of treated and untreated samples. The ash removal and combustible separation efficiency of the synthetic mixture improved after chemical conditioning of the synthetic mixture with ethanol, acetone, acetic acid, and aniline. However, aniline treatment has produced the best separation result. It is possible to achieve 9 and 14% ash clean coal with 40% yield each from 53% ash synthetic mixture at 15 kV applied voltage after aniline and heat treatment, respectively. The ash removal and combustible separation efficiency of the tribo-electrostatic separator for the aniline and heat-treated synthetic mixture are 96, 60% and 90, 70%; respectively. (c) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.