Preliminary evaluation of Halocarbon 0.8 oil's impact on metallurgical coal quality

Heavy organic liquids are typically used for coal laboratory float and sink testing. Perchloroethylene (PCE), methylene bromide and naphtha are typical liquids used in labs worldwide to create baths with a wide range of specific gravities. All three of these liquids are harmful to human health and can have negative effects on coal rheology. Perchloroethylene is a solvent that has been used to remove organic sulfur from coal prior to use in power generation plants. The PCE acts as a swelling agent and when heated in the presence of a catalyst, will cleave the C-S bonds, removing organic sulfur from the coal. PCE is a clear liquid however after the float and sink process it turns shades of yellow to dark brown. Portions of the coal become suspended in solution and many organically bound elements are released from the coal into the solution. This may result in certain elements being underestimated in the clean coal products arising from perchloroethylene based float and sink. The float and sink test assesses metallurgical coal washability using organic liquids, but traditional options like naphtha, perchloroethylene, and methylene bromide pose health risks. This study examines the effects of four liquids on coal quality and chemistry.