Abstract: Based on the follow-up of actual production data from calcining cobalt carbonate to produce cobalt oxide using a rotary kiln, this paper investigates the factors influencing the quality of cobalt oxide produced from cobalt carbonate under scaled-up production conditions. The calcination efficiency of cobalt carbonate is evaluated based on the carbon content in the cobalt oxide, while the hourly feeding rate is used to assess production efficiency. The results indicate that to ensure a carbon content below 0.1%, the calcination process should be set as follows: a cobalt carbonate feeding speed of 900 kg/h, a temperature of 700 ℃ in the high-temperature zone of the rotary kiln, an air inflow of 650 m³/h, an induced draft frequency of 17 Hz, and a rotation frequency of 22 Hz.