The Effect of Ultrasonic Treatment on Alumina Leaching from Calcium Aluminate Slag

The effect of ultrasonic treatment on the alumina leaching properties of calcium aluminate slags was investigated. The effects of the main leaching parameters such as ultrasonic power, leaching time, leaching temperature, and the concentration of sodium carbonate on alumina leaching rate were determined. The mechanism of ultrasonic effects on leaching is also discussed. It was found that the increase in leaching rate was slight, but leaching conditions were improved significantly when ultrasonic treatment was used in the leaching process. Leaching temperature and sodium carbonate concentration decreased by 30°C and 60g•L−1 respectively with the addition of ultrasonic treatment. Ultrasonics would not promote the decomposition of y-2CaOSiO2. The agglomeration of leaching residue was prevented by the cavitation and mechanical effect of ultrasonic treatment.