Facing the challenges of ultrafine coal recovery

Abstract

In the past there was often valid economic justification for not processing the ultrafine coal fractions and it was common to simply discard them as tailings. The trend is now to extract as much coal value as possible in the preparation process across all size ranges and to optimise performance and recovery. In addition, social, environmental and legal pressures to address concerns over power and water conservation drive incentives to maximise coal value recovery. The issues associated with processing, dewatering and handling of fine coal and reject streams are complex and significant and call for better management solutions to qualify admission of fine coal into products. These include, maximised solids capture, improved operating performance, reduced water consumption and increased water recycling. The development of alternatives to existing processing and dewatering technologies along with the better understanding of existing processes are essential to achieving better ultrafine (<50micron) coal recovery. In this paper, the authors review new and emerging beneficiation options. In addition to these, a number of established technologies have been improved and new versions of processes once considered unviable now have the potential to become solutions for the issues facing ultrafine coal treatment.