POISONS, POLYOLS AND PRECIPITATION
Owen, A., Watling, H.R., van Bronswijk, W. and Yu, Z.S.
Polyols are organic compounds with a hydroxyl functional group at every carbon atom. They are related closely to the simple sugars, and are active in physiological processes, at least in part because of their ability to form strong complexes with multivalent cations. Their value to us is in the use of their complexation properties to probe the mechanisms of poisoning of gibbsite precipitation under strongly alkaline conditions.
Methods have been developed with which the effects of organic compounds on specific precipitation processes (gibbsite nucleation, agglomeration and growth) and their adsorption on a partially hydrated alumina (gibbsite-like) surface can be quantified. Data obtained from these studies have been supplemented by mechanistic information about their interactions with aluminate ions and with a gibbsite-like surface, obtained using NMR and vibrational spectroscopy.
The comparative results obtained are discussed in relation to the mechanisms by which polyols might interact with a gibbsite surface.