A series of sorbents for flue gas SO2 scrubbing have been prepared from hydrated lime (HL) and blast furnace slag (BFS) with the factorial experiment design method. The sorbents were characterized and tested for SO, reactivity in a differential fixed-bed reactor. It was found that, due to the formation of calcium silicate hydrates (CSHs), the reactivities of the sorbents prepared were higher than that of Ca(OH)(2) alone. The present sorbent gave better utilization of the Ca originated from the Ca(OH)(2) precursor and provided additional utilization capacity of the Ca derived from BFS. The present sorbents were mesoporous, and their specific surface areas were linearly correlated with their mesopore volumes. When the weight ratio of BFS/HL varied between 1/9 and 3/7, the SO2 capture of the sorbents prepared was independent of specific surface area. When the weight ratio of BFS/HL varied between 7/3 and 9/1, the SO, capture was seen to increase linearly with specific surface area. Among the four process variables studied for the sorbent prepared in this work, the weight ratio of BFS/HL was found to be the most significant for the specific surface area of the sorbents. The optimum BSF/HL ratio looked to be around 9/1. The second and the third process variables studied were hydration time and the ratio of water/solid, respectively. The optimum hydration time was about 10 h. while the optimum water/solid ratio was 25/1. The last process variable studied was slurrying temperature. Slurrying temperature (T) had little effect on the specific surface area of the BFS/HL sorbent in the range 50-80 degrees C. This is useful for preparing high-performance silica-enhanced desulfurization sorbents for dry and semidry flue gas desulfurization processes, taking advantage of the waste BFS.