To get more knowledge about the characteristics of coal combustion under low oxygen concentration conditions

thermogravimetric experiments were carried out using two kinds of coal samples(lignite coal and coking coal)

in atmospheres with oxygen concentration below that in the air.Via analyzing the TG-DTG data obtained from the experiments

the characteristic temperatures of the coal samples during the whole combustion process can be calculated.Moreover

the relationship between the special temperatures and oxygen concentration

like the maximum mass loss rate temperature and burnout temperature

was fitted.The results show that

the temperature corresponding to the maximum mass loss rate point decreases with the increasing oxygen concentration

which has been described as a linear relationship.With an ultra low oxygen concentration

the burnout temperature of different coals is close to each other

indicating the burnout temperature has no relationship with the coal quality.With an increase in the oxygen concentration

the burnout temperature decreases

and when the oxygen concentration is higher than a certain value

the burnout temperature tends to be stable.The dry lignite is easier to be ignited than the dry coking coal.The results has a certain instruction for prevention and treatment of high temperature and low oxygen underground coal mine fire phenomenon.