Salting-out precipitation of potassium dihydrogen phosphate (KDP) III. Growth process

The growth of KDP produced by salting-out from aqueous solutions with different contents of ethanol, l-propanol and 2-propanol have been studied at 30 degrees C. The influence of initial supersaturation ratio (between 1.11 and 1.45), the type and alcohol content (from 5 to 15 g/100 g of water) and also the agitation intensity (between 50 and 500 rpm) were analysed. The results obtained from desupersaturation curves, followed conductometrically, and expressed in terms of the degree of precipitation, and also from mass deposition curves for ethanol systems, suggest a kinetic first order growth process. It was possible to conclude that the three co-solvents interfere with the growth process which is also influenced by the agitation intensity. (C) 1998 Elsevier Science B.V. All rights reserved.