Impact of hydrodynamic conditions on gypsum growth
Vol.18,No.2(2011)
Abstract
Keywords:
gypsum; crystal growth; induction time; hydrodynamic conditions; nucleation; rate
The interaction of gypsum (CaSO4.2H2O) with water is controlled by mixed transport-surface reaction kinetics. Therefore, the rate of gypsum growth/precipitation should depend on hydrodynamic conditions. Gypsum nucleation and crystal growth were studied in a batch reactor under ambient conditions in dependence on varying hydrodynamic conditions (advection of solution). The statistically significant dependence (R2 = 0.875), u = 4.10-7 v+0.0007 (where u is crystal growth rate in mol/min and v is stirring rate in rpm) was found for gypsum growth rate and stirring rate of solution. In contrast, induction times at gypsum nucleation were slightly increasing, i.e., nucleation rates decreased with increasing stirring rate. However, no statistically significant dependence (R2 = 0.115) was found.
gypsum; crystal growth; induction time; hydrodynamic conditions; nucleation; rate
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