Charging mechanism analysis of macerals during triboelectrostatic enrichment process: Insights from relative dielectric constant, specific resistivity and X-ray diffraction. (1st August 2018)

• Record Type: Journal Article
• Authors: He, Xin; Sun, Hao; Chen, Xiaowei; Zhao, Bin; Zhang, Xinxi; Komarneni, Sridhar
• Is Part Of: Fuel. Volume 225(2018)
• Page Start: 533
• Page End: 541
• Publication Date: 2018-08-01
• Subjects: Relative dielectric constant -- Specific resistivity -- X-ray diffraction -- Triboelectrostatic separation; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2018.03.189
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Relative dielectric constant and its changes under various environmental conditions. Specific resistivity of macerals and its impacts on triboelectrostatic separation. Vitrinite and inertinite structures by XRD and relevance to electrical properties. Abstract: With increasing need for coal liquefaction, the separation and enrichment of active maceral (vitrinite) in feed coal has become the research focus for increasing liquefaction yield from coal. Vitrinite and inertinite could be separated and enriched in negative coal flow and positive coal flow, respectively by triboelectrostatic method. In order to analyze the tribo-charging mechanism of macerals, their relative dielectric constant (RDC) and specific resistivity were measured in this work. Lower RDC of vitrinite corresponds to its positive charge during separation while inertinite has the opposite actions. The wider RDC and closer specific resistivity gaps between the two macerals could form more distinct separation track and achieve better yield and enrichment of vitrinite. X-ray diffraction characterization results show that inertinite with high La (12.18 Å) is harder to lose electrons and charges negative compared with vitrinite ( La 9.57 Å) in the separation, this also matches their different RDCs. Besides, the active small groups represented by largerγband area and higher amorphous carbon content of vitrinite could be a reason for its lower specific resistivity.