Abstract: The calcination process of metallurgical active lime in a rotation kiln was simulated in laboratory. It is found that preheating temperature, pre-heating time, calcination temperature and calcination time are the most important factors in this process. The optimal parameters is the pre-heating temperature of 700℃, the pre-heating time of 60 min, the calcination temperature of 1150℃, and the calcination time of 15 min. Under this optimal condition, the activity of active lime produced by the raw material of limestone from Xuanhua Steel in China is 410 mL.