Turkish celestite ore was roasted in a lab scale rotary kiln furnace with metallurgical coke. Coke and celestite were mixed; the product contained 32% coke which is more than the stoichiometric requirement. 100 g of the mixed product was fed to a rotary furnace at 35 g/min. Temperature (1000 and 1100 degrees C), rotation speed (2.5, 5 and 10 rpm) and the slope of the furnace (2, 3 and 5 degrees) were among the investigated parameters. Phase and chemical analyses were carried out by XRD and XRF techniques, respectively. The maximum solubility of the roasted product in water was 48% under the roasting conditions of 1100 degrees C, 2.5 rpm and 2 degrees slope.