This is a research report of the effects of process variables on the reactivity of slaked lime produced from Shuk quicklime. It involved the calcination (at temperature of 1000 ⁰C, particle size of 90 µm and time of 3 hrs) of Shuk limestone and subsequent slaking of its quicklime. The quicklime was characterized by x-ray diffractometer (XRD) and scanning electron microscopy (SEM) respectively to determine its mineral content and surface morphology respectively. Effects of process variables (quicklime/water ratio, particle size and time) on the reactivity of the slaked lime were determined. The reactivity was optimized using response surface methodology (RSM). The XRD analysis revealed calcite as the type mineral of the Shuk quicklime. The surface morphology of the quicklime sample showed that the particles are packed together in powdered form with visible pores that will allow passage of water. Reactivity of the lime was influenced by the quicklime/water ratio, particle size and time. Quadratic model appropriately explained the relationship between reactivity and considered slaking factors of quicklime/water ratio, particle size and time. The optimum reactivity value of the slaked lime was obtained as 59.3 ^oC at quicklime/water ratio of 0.24 g/ml, particle size of 88.2 µm and time of 15.1 minutes.