2007 Volume 86 Issue 7 Pages 455-461
The aim of this paper is to investigate boron species in coals in order to research partitioning of boron in pulverized coal-fired process. Some extracted coal samples using specific gravity separation and these LTA (Low Temperature Ash) samples were treated with leaching of pure water. Solid-state MAS 11B-NMR spectra of these coals and LTA samples were obtained. Chemical shift of boron species in coal was observed both trigonal and tetrahedral coordinated boron and existent ratio was different with kinds of coal. It was estimated that a part of boron in coal was existed as water-soluble compounds and its chemical form was boric acid and its anhydride, borate of alkaline and alkaline earth metals, and then these compounds minutely dispersed in organic matter of coal.