The study of enhanced gravity concentrator for maceral enrichment of low-rank coal with heavy medium

Abstract

ABSTRACT The enhanced gravity concentrator with water medium has been used for the low-rank coal maceral enrichment and achieved a favorable effect. This study utilized the magnetite powder as the separation medium in the enhanced gravity separation test. The enhanced gravity separation with different medium was contrasted, the heavy medium separation possessed a more excellent separation mechanism and better effect, and the vitrinite content and recovery of concentrates was increased to 80.40 vol.% and 54.85%. In addition, the results of float–sink test and enhanced gravity separation with heavy medium were compared under the same separation density, the difference of vitrinite content and between the two methods was below 5%, and the vitrinite recovery of enhanced gravity separation was increased to 77.9% with the separation medium of 1.40 g/cm3. The density difference of macerals was proved by the EDS and XRD measurement, the more quantity of polycondensation aromatic rings and tighter microcrystalline structure leads to the higher density of inertinite.