title: Ultrasound precipitation of manganese carbonate: the effect of power and frequency on particle properties.
abstract: The influence of ultrasonic frequency and intensity on particle shape, tap density and particle size distribution was investigated during the precipitation of manganese carbonate. For the first time, a broad frequency range of 94 till 1135 kHz was studied in one single reactor setup. Smaller and more spherical particles were observed during sonication compared to silent conditions. Lower frequencies and increased intensities result in smaller and more spherical particles. The most spherical particles with superior tap densities are obtained at the lowest frequency and most elevated intensity. Moreover, the results indicate that a particle size threshold exists, below which the particle size cannot be reduced by a further increase of the ultrasonic intensity or reduction of the frequency. Sonication of already formed spherical powders resulted in particles with smaller sizes but unaffected shapes. Finally, one test with pulsed ultrasonic irradiation resulted in equally sized particles with similar sphericity as the ones produced under continuous sonication.
authors: Department of Chemical Engineering, KU Leuven, De Croylaan 46, B-3001 Leuven, Belgium; Researchgroup Lab4U, Faculty of Industrial Engineering, KU Leuven, Belgium. Electronic address: jeroen.jordens@cit.kuleuven.be.
authors: Jeroen
authors: J
authors: Jordens
authors: Department of Chemical Engineering, KU Leuven, De Croylaan 46, B-3001 Leuven, Belgium.
authors: Nico
authors: N
authors: De Coker
authors: Researchgroup Lab4U, Faculty of Industrial Engineering, KU Leuven, Belgium.
authors: Bjorn
authors: B
authors: Gielen
authors: Department of Chemical Engineering, KU Leuven, De Croylaan 46, B-3001 Leuven, Belgium.
authors: Tom
authors: T
authors: Van Gerven
authors: Researchgroup Lab4U, Faculty of Industrial Engineering, KU Leuven, Belgium.
authors: Leen
authors: L
authors: Braeken
keywords: Particle engineering; Process intensification; Sonochemistry; Ultrasound precipitation; Ultrasound shaping