Abstract
The previous studies concerning the air-oxydation of coals have been made mostly on the view points of the .weathering, the variation of coking property, the spontaneous ignition, etc.The air-oxidation of humic substances of lignite was carried out as the pre-treatment of the wet-oxidation of them aiming to obtain some valuable organic chemicals.This time we determined the elementary composition, the acidic groups, the active oxygen, the humic acids and the ash content of the oxidized coal which remained in the reaction tube after the reaction had finished.From these data the reaction mechanism was discussed.
