Mineral species bonded to organic parts in coals of South Banko (SB), Enshu (EN), and Nantun (NT) were characterized by solid-state ^<29>Si- and ^<27>Al-NMR and ICP-ES measurements, in order to clarify their elution behaviors during solvent extraction and acid treatment. Some portions of silicates and aluminates bonded to organic parts in the coals were identified by the solid-state ^<29>Si-NMR analyses, although their contents were dependent on the coal rank It was also revealed that some of aluminosilicates were extracted by acid treatment room temperature and solvent extraction at high temperatures around 350℃. The former treatment mainly removed ion-exchangeable cations such as alkali and alkali-earth metals, while the latter extraction principally eluted aluminosilicates and Ca species which were relatively stable during the high temperature solvent extraction conditions. Ca-containing aluminosilicates are suggested to be one of the major organically associated species in the coals.
