Development of a characteristic flotation cleaning index for fine coal

Cleaning index values provide valuable information for assessing the abilit y to concentrate a mineral in an ore using a given physical property and fo r selecting the appropriate separation technology. In response to the recen t developments of advanced froth flotation technologies and flotation chara cterization procedures, a flotation index (FI) has been developed which can be utilized to quantitatively assess the flotation cleaning potential of a given coal sample. Along with an overall FI value, two separate FI values have been determined for each coal to separately characterize the negative selectivity effects caused by the presence of mixed-phase particles and the suppressed recovery rates caused by a lower degree of hydrophobicity of th e coal particles. Separate FI values have been determined for ash and sulfu r cleaning, which indicate the superior ash cleaning and relatively inferio r sulfur cleaning performances achievable by froth flotation. (C) 1999 Else vier Science B.V. All rights reserved.