Crystallization of potash alum: effect of power ultrasound

The influence of power ultrasound on the crystallization of potash alum was investigated. Experiments have been carried out in a batch stirred vessel. It was found that ultrasonic waves decrease the supersaturation limits and modify the morphology of the crystals produced. The average crystal size d ecreases with an increase of ultrasonic pourer. To investigate also the act ion of ultrasound on already existing crystals, crystals produced in silent conditions were suspended in saturated potash alum solution at various ult rasonic powers. The results show that ultrasound has also an abrasive effec t on potash alum crystals for high power inputs. (C) 2001 Elsevier Science B.V. All rights reserved.