Mechanically Stimulated Thermal Synthesis of Lithium Pentaaluminate from Lithium Carbonate and Aluminum Hydroxide

Resumo

It is shown that the phase composition of lithium aluminates formed when aluminum hydroxide in the form of gibbsite interacts with lithium carbonate in their mixture with Al: Li atomic ratio of 5: 1 depends on the duration of a preliminary mechanical activation of the mixture and on the temperature of the subsequent thermal treatment. A thermal treatment of the starting mixture at temperatures exceeding 800°C yields LiAl₅O₈ with a substantial admixture of α- and γ-LiAlO₂. Raising the duration of the mechanical activation to 5 min and more makes it possible to obtain highly dispersed single-phase LiAl₅O₈ with a specific surface area larger than 20 m² g^–1