Centrifugal Dewatering and Reconstitution of Fine Coal: The GranuFlow Process

Abstract

This paper describes the continuous bench-scale testing of the GranuFlow Process, developed and patented by the Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy. Testing was conducted on both high-g force solid-bowl and screen-bowl centrifuges for dewatering and reconstitution of fine-clean-coal slurry at 300 Ib/h (136 kg/hr) in PETC7's Coal Preparation Process Research Facility. In the GranuFlow Process, fine-clean-coal slurry was treated with a bitumen emulsion before dewatering in both centrifuges. In one example, the treated products from a solid-bowl centrifuge appeared to be dry and in a free-flowing granular form, while the untreated products were wet, lumpy, sticky, and difficult to handle. Specifically, test results from the solid-bowl centrifuge indicated that the moisture content, handleability, and dust reduction of the dewatered coal product improved as the addition of emulsion increased from 2 wt% to 8 wt%. The improvement in handleability was most visible for the ...