Ageing of precipitates

Suito, E. and Takiyama, K. (1954) Formation and aging of precipitates. I. Electron microscopic studies of the formation of barium sulfate precipitate. Bull. Chem. Soc. Japan, 27, 121-123. 

Figure 9.12 Typical transformations during phase transformations at Aps<1 (a) and (b) for powders and granules (c)-(f) for aging of precipitates in liquid phase (recrystallization).

Hahn (1931) applied the method to studies of the ageing of precipitates. The emanating power of freshly formed, dry iron(III) hydroxide is high and falls by only about 2% a year. Digestion in water quickly reduces the emanating power, indicating a rapid ageing. 

PZC/IEP of Ferrihydrite Obtained by Aging of Precipitate Obtained at pH 10 from 0.05 M FelNOjla and KOH... 

The solid phase involved is essentially assumed to be an infinitely large, defect- and impurity-free crystal with a well-defined structure. Microscopic crystals have higher solubilities than large crystals, a well-known phenomenon that leads to aging of precipitates, in which larger crystals grow at the expense of smaller ones. 

Hanitzsch, E. and Kahlweit, M. (1969) Ageing of precipitates. Symposium on Industrial Crystallization, Institution of Chemical Engineers, London, 130-141. 

Mullin, J.W., Murphy, J.D., Sohnel, O. and Spoors, G. (1989) Ageing of precipitated magnesium hydroxide. Industrial and Engineering Chemistry Research, 28, 1725-1730. 

I. Shapiro and I.M. Kolthoff, Studies on aging of precipitates and copredpitation. XLIII. Thermal aging of... 

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