Experimental study on the effect of immersion duration on low temperature oxidation characteristics of undried coal
SUN Jinchuan
QIN Yueping
TANG Fei
Abstract：In order to simulate the low-temperature oxidation process of coal samples immersed in mine water and explore the effect of immersion time on the low-temperature oxidation characteristics of undried coal,through the self-developed gas-bath coal low-temperature oxidation experimental system,programmed temperature experiments were conducted on 12 groups of undried coal samples with different immersion durations in Anze Mining Area.The gas production and apparent activation energy changes of coal at different stages of low-temperature oxidation were analyzed,and the microscopic mechanism was discussed based on the experi-mental results.The results show that different temperature stages and immersion durations have varying effects on the low-temperat-ure oxidation ability of coal.Before 75℃,moisture has an inhibitory effect on coal oxygen reaction and the longer the immersion time,the more significant the inhibitory effect,specifically,the volume fraction of exported oxygen and the apparent activation en-ergy during the slow oxidation(SⅠ)stage gradually increase with increasing immersion time,while the standard oxygen consump-tion rate and standard carbon monoxide generation rate gradually decrease with increasing immersion time;after 75℃,moisture pro-motes the coal oxygen reaction,and the longer the immersion time,the more obvious the promoting effect,specifically,the export oxygen volume fraction and apparent activation energy of the accelerated oxidation(SⅡ)stage gradually decrease with increasing immersion time,while the standard oxygen consumption rate and standard carbon monoxide generation rate gradually increase with increasing immersion time.According to the inference,this is related to a series of complex physical and chemical changes that oc-cur inside the coal sample after water immersion,before 75℃,the moisture in the coal absorbs heat and evaporates,hindering the diffusion of oxygen and inhibiting the coal oxygen reaction;after 75℃,a large amount of water evaporates from the coal,and under the erosion of water,the physical structure of the coal body changes,while also exposing more chemical groups.Some chemical re-actions release heat,jointly promoting coal oxygen reactions.
Keywords：spontaneous combustion of residual coalwater-immersed coalwater-immersed coal samplelow-temperature oxida-tion of coalapparent activation energymicroscopic mechanism
Publication Date：2026-02-20
Online Publishing Date：2026-03-19(First online date of this platform, not the publication date of the document)
Pages：9( 115-123 )