Acoustic influence on aggregation and agglomeration of crystals in reaction crystallization of cerium carbonate

Abstract Sonication and turbulent agitation were used to investigate the mechanism of crystal aggregation and agglomeration during the reaction crystallization of cerium carbonate. Aggregation and agglomeration occurred simultaneously during the crystallization, thus the product suspension included both crystal aggregates and agglomerates. As crystal aggregation involves the physical adhesion of crystals, the particle size changed sensitively according to the sonication energy and agitation speed during the crystallization. In contrast, since crystal agglomeration is based on molecular growth following crystal aggregation, the agglomerates were strong enough to resist the acoustic impact of the sonication and turbulent shear of the agitation during the crystallization. Thus, the crystal aggregates in the product suspension were completely re-dispersed by an acoustic after-treatment of 30 W for 20 min. Acoustic after-treatment was also used to determine the agglomerate size and estimate the degree of aggregation of the product suspension. As a result, sonication above 60 W was found to be adequate to prevent any aggregation or agglomeration during the crystallization, regardless of the agitation conditions.

[1]  Ronald W. Rousseau,et al.  Agglomeration of copper sulfate pentahydrate crystals within well-mixed crystallizers , 1989 .

[2]  Michael J. Hounslow,et al.  A micro-mechanical model for the rate of aggregation during precipitation from solution , 2001 .

[3]  S. Simons,et al.  Hardness of moist agglomerates in relation to interparticle friction, granule liquid content and nature , 2001 .

[4]  Alan Jones,et al.  Particle disruption of precipitated CaCO3 crystal agglomerates in turbulently agitated suspensions , 1998 .

[5]  M. Mitrić,et al.  Ultrasonic de-agglomeration of barium titanate powder. , 2008, Ultrasonics sonochemistry.

[6]  Å. Rasmuson,et al.  Agglomeration of Paracetamol during Crystallization in Pure and Mixed Solvents , 2004 .

[7]  Woo-Sik Kim,et al.  Crystal agglomeration of europium oxalate in reaction crystallization using double-jet semi-batch reactor , 2004 .

[8]  René David,et al.  Crystallization and precipitation engineering—III. A discrete formulation of the agglomeration rate of crystals in a crystallization process , 1991 .

[9]  Alan Jones,et al.  Experimental investigation into dynamics and stability of continuous MSMPR agglomerative precipitation of CaCO3 crystals , 1997 .

[10]  Paul Lant,et al.  Activated sludge flocculation: on-line determination of floc size and the effect of shear , 2000 .

[11]  S. Kresta,et al.  The effect of stabilizer addition and sonication on nanoparticle agglomeration in a confined impinging jet reactor , 2009 .

[12]  M. Cournil,et al.  Using a turbidimetric method to study the kinetics of agglomeration of potassium sulphate in a liquid medium , 1991 .

[13]  C. Y. Tai,et al.  Nucleation, agglomeration and crystal morphology of calcium carbonate , 1995 .

[14]  E. T. White,et al.  Agglomeration during precipitation: I. Tracer crystals for Al(OH)3 precipitation , 1995 .

[15]  Alan Jones,et al.  A Novel Experimental Device for Measurement of Agglomerative Crystallization Forces , 2002 .

[16]  F Pratola,et al.  Toward a molecular understanding of crystal agglomeration , 2005 .

[17]  J. Hostomský,et al.  Calcium carbonate crystallization, agglomeration and form during continuous precipitation from solution , 1991 .

[18]  Alfons Mersmann,et al.  Prediction of crystallization coefficients of the population balance , 2002 .

[19]  Å. Rasmuson,et al.  Mechanisms of Crystal Agglomeration of Paracetamol in Acetone−Water Mixtures , 2005 .

[20]  M. Kass.  Ultrasonically induced fragmentation and strain in alumina particles , 2000 .

[21]  E. T. White,et al.  Agglomeration during precipitation: agglomeration mechanism identification for Al(OH)3 crystals in stirred caustic aluminate solutions , 1994 .

[22]  H. Schuchmann,et al.  Influence of hydrostatic pressure and sound amplitude on the ultrasound induced dispersion and de-agglomeration of nanoparticles. , 2008, Ultrasonics sonochemistry.

[23]  Michael J. Hounslow,et al.  Agglomeration during precipitation: II. Mechanism deduction from tracer data , 1995 .

[24]  A. Gierczycki,et al.  Influence of ultrasonic conditioning of flocculant on the aggregation process in a tank with turbine mixer , 2010 .

[25]  Å. Rasmuson,et al.  Agglomeration and adhesion free energy of paracetamol crystals in organic solvents , 2007 .

[26]  Woo-Sik Kim,et al.  Agglomeration of yttrium oxalate particles produced by reaction precipitation in semi-batch reactor , 2000 .