Optimization Study on the Microwave Drying of Red Mud Using Response Surface Methodology

As a kind of industrial waste from aluminum production, red mud is rich in valuable metal elements and has high comprehensive utilization value. The effects of microwave power and material amount on the temperature rise behavior of red mud were investigated. The results show that the heating rate of red mud is directly proportional to the microwave power and inversely proportional to material amount. Based on the single factor experiment, the optimization experiment of response surface method was carried out. The effects of microwave power, material amount and drying time on the dehydration rate of red mud were investigated respectively. The mathematical model between each factor and dehydration rate was established, and the optimization process parameters of response surface of microwave clean drying red mud were obtained: Control of microwave drying temperature was 100 ℃, microwave power was 700 W, material quantity was 50 g, drying time was 12 min, dehydration rate of red mud was 97.95%, and the model prediction was similar (98.58%). The results laid a certain experimental foundation for the resource utilization of red mud.