Maintaining coals treated respectively with three surfactants (surface covering agents) in constant temperatures (90°C, 110°C, 130°C and 140°C in separate experiments), covering efficacies of each agents against incipient oxidation of coals, spontaneous combustion, are tested with quantity of oxygen deficiency and carbon monoxide produced while in 12 hours from the start of reaction.
Considerable decrease of both quantities during each reactions are observed, namely, restraining actions against coal oxidation of certain surface covering agents are recognized.
In spite of constant temperature conditions, fixed relations between validities and used concentrations, and restraining behavior of surface covering agents are not confirmed quantitatively, because of the complexity in chemical connection between oxygen deficiency and carbon monoxide produced during each reactions.
