Influence of coal particle size on the combustion characteristics of yuanbaoshan lignite

To support the choice of the particle size for practical industrial use, the thermogravimetric analysis was used to investigate the influence of particle size on the combustion characteristics of Yuanbaoshan lignite. The analysis of the combustion characteristic parameters of thermogravimetric curve indicates that with the decrease of the particle size, the ignition of the pulverized coal is advanced and the time for burnout is shortened, this means the increase of the combustible indices C and synthetic combustion indices S, which shows that the combustibility of the coal is improved. The method of Coats-Redfern was used to obtain the kinematic parameters. It shows that the TG combustion reaction of Yuanbaoshan lignite is one-order reaction. The total process can be considered as two seperated stages, one is before the maximum burning velocity and the other is after that. As the particle size decreases, the apparent activation energy for both of the two stages and the weight average apparent activation energy decrease. The study indicates that the decrease of the particle size of the pulverized coal can improve the conbustibility.