Conference Dates

May 1-5, 2011


The influence of temperature, heating rate and chemical reaction on fragmentation

and attrition of limestone in a fluidized bed (FB) was investigated. The intensity of

fragmentation and attrition was measured in the same apparatus but at different

fluidizing velocities and fluidizing media. It was found that the heating rate has a

positive effect on fragmentation for the tested limestones. The effect of bed

temperature on limestone fragmentation was inconclusive. The influence of

chemical reaction on the fragmentation seems to be complicated; CO2 release due to

calcination would prompt fragmentation while the sulfation would increase the gas

diffusion resistance and depresses the fragmentation intensity. On the other hand,

the CaSO3/CaSO4 layer was found to be attrition-resistant leading to small attrition

rates. Attrition rate constant showed to decay exponentially with time and

approaching a constant for all limestone particles. Particle sizes between 200-400 µm

have larger attrition rate constant than coarse ones perhaps due to their large specific

surface area.