龙岩煤不同宏观煤岩组分的热破碎性质研究

Three different lithotypes of Longyan (LY) anthracite with different particle size were separated by means of flotation technique. Experiments of the particle fragmentation during pyrolysis and combustion were conducted in a TGA system and a pilot scale fluidized bed furnace, respectively. It is shown that for clarain and culm many new fine particles are generated during pyrolysis, most of which has a size smaller than 0.8mm. The primary fragmentation reaction of clarain and clum becomes severely with the increase of heating rate and the sample particle size. For durain particle, no obvious fragmentation is found under the same experimental condition. Factors, such as particle properties, particle size, furnace′s bed temperature and combustion time, have an important effect on the fragmentation of LY anthracite during its combustion in fluidized bed. Clarain and culm occur tremendous fragmentation in fluidized bed due to their compact structure, few large pores in inner particle, high microscopehardness (Hm,v) and low ash content. The fragmentation of clarain and culm tends to be severely with the increase of particle size, bed temperature and combustion time. Durain doesn′t have obvious fragmentation during combustion in fluidized bed. Both clarain and culm undergo the secondary fragmentation during combustion, but the secondary fragmentation of clarain is severely in the late stage of combustion. The particle size of clarain declines more rapidly than that of culm. In the early stage of combustion, the mean particle size of clarain decreases promptly as a result of primary fragmentation, but with the time going it falls to a stable size. The combustion model of clarain in fluidized bed is equidensity shrinking core model, while that of durain is equidiameter one, and that of culm is a mixed model.