Original paper
Effect of crystallinity on diaspore and boehmite relative stability
Gout, Robert; Verdes, Giles
European Journal of Mineralogy Volume 5 Number 2 (1993), p. 215 - 218
13 references
published: Apr 19, 1993
manuscript accepted: Dec 2, 1992
manuscript received: Mar 29, 1991
DOI: 10.1127/ejm/5/2/0215
Abstract
Abstract Solubility measurements of boehmite and diaspore carried out in alkaline solutions demonstrate that diaspore is the stable phase at temperatures lower than 380°C. However, it is impossible to synthesize purely aluminous diaspore in the laboratory at low temperatures and pressures. Synthesis of ferriferous diaspore at low temperature exhibits the initial precipitation of a poorly crystallized variety of diaspore which subsequently transforms into well crystallized diaspore. The solubility of poorly crystallized diaspore (purely aluminous) is equal to or slightly greater than that of boehmite. Thus, at low temperature and pressure, diaspore can form only when foreign ions (like iron) substitute in place of aluminium in its lattice to stabilize it
Keywords
solubility • thermodynamic properties • aluminium oxyhydroxide • boehmite • diaspore • metastability