A large amount of fine domestic limestone (< 0.1 mm) is being disposed because of several potential problems in circulating fluidized bed combustion (CFBC). To increase the utilization of fine particulate limestone, the present work investigated the effect that modification in the size distribution of limestone adsorbents has on fly ash, whcih is used as the additive of Portland cement. The analysis resulted from an industrial-scale test that ensured that a new sorbent containing 50% of small particles could be acceptable for application to the cement industry. The dust collection efficiency of an electrostatic precipitator (EP) was also quite high (99.99%), as high as the conventional particle distribution of the feed limestone.