Upgrading the Indonesian's Low Rank Coal by Superheated Steam Drying with Tar Coating Process and its Application for Preparation of CWM

Abstract

An upgrading process of Indonesia low rank coal, which consists of atmospheric superheated steam drying and tar coating process was proposed to improve the coal quality. An experiment using Sumatera Bunko coal, which is a lignite class coal, has been carried out. The effects of upgrading parameters such as coal size, steam temperature, drying time and tar-coating process were investigated. The coal upgrading process on pulverized coal for CWM preparation was also done. CWMs with various coal concentrations were prepared using the upgraded coal as well as the just steam-dried coal as raw material. Polystyrene sulfonate (PSS) was used as dispersing additive in the CWM. The obtained CWMs were characterized and compared. The comparison with some CWM prepared by other methods is also discussed.