Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Combining advanced flotation and centrifugal gravity separation for improved sulfur rejection

Book ·
OSTI ID:143767
; ;  [1]
  1. Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Center for Coal and Minerals Processing

Recent studies conducted at the Center for Coal and Minerals Processing (CCMP) indicate that surface-based processes such as froth flotation are inefficient in removing pyrite from fine coal. This shortcoming has been attributed to the fact that pyrite can become hydrophobic under certain conditions and to the inability of flotation to effectively reject middlings particles. To overcome these deficiencies, a new processing scheme has been developed at CCMP which involves the use of the Microcel{trademark} flotation column in combination with a centrifugal flowing-film separator, called a Multi-Gravity Separator (MGS). The flotation column primarily removes ash-forming minerals such as clay, while MGS is effective in removing pyrite. Preliminary test data obtained with high-sulfur coals show that this processing scheme can nearly double the pyritic sulfur rejection with little loss (< 5 %) in clean coal yield. This article discusses the underlying principles of the new circuit and provides results obtained using eastern US coals. The major advantage of the circuit is that high levels of pyritic sulfur rejection can be achieved without fine grinding.

OSTI ID:
143767
Report Number(s):
CONF-9305264--
Country of Publication:
United States
Language:
English