Premium
The precipitation of aluminium hydroxocarbonates powders from aqueous solution: Precipitate compositions and precipitation mechanisms
Author(s) -
Packter A.,
Panesar K. S.
Publication year - 1987
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170220805
Subject(s) - carbonate , precipitation , dissolution , aqueous solution , chemistry , inorganic chemistry , sodium carbonate , aluminium , aluminium nitrate , nuclear chemistry , sodium , organic chemistry , physics , meteorology
A series of aluminium hydroxocarbonate hydrates were prepared by precipitation from aluminium nitrate solution, with five sodium hydrogen carbonate‐sodium carbonate solutions of different p H, at ambient temperature. The course of precipitation was monitored by p H measurement and the final precipitate compositions were determined by chemical analysis, infra‐red spectrophotometry, X‐ray diffraction and thermal analysis. Precipitation generally occurred through three stages, primary precipitation of materials with low carbonate content at low p H with evolution of carbon dioxide, their dissolution to form hydroxcarbonato anions and then secondary reprecipitation of the final products at higher p H. These materials were mixtures of polyhydroxoaluminium carbonate hydrates of general composition Al n (OH) 3 n ‐2 CO 3 · h H 2 O (where n = 2, 4, 6 and h = 6–8); their CO 3 content increased with increasing p H and carbonate anion content of the precipitant solution.