Study of the process of dissociation of lithium carbonate in the presence of aluminum powder

The results of a study of the dissociation process of lithium carbonate in vacuum in the presence of aluminum powder are presented. It is revealed that at a process temperature of 700°C, the degree of dissociation achieves ∼60% and the thermal decomposition of lithium carbonate retards. It follows from the phase diagram of the Li 2 CO 3 -Li 2 O system that an increase in the temperature leads to the appearance of a liquid phase. On the basis of the experimental data with the use of the half-division method, a maximum rate of heating from 700 to 740°C of 0.33 ± 0.02°C/min is determined at which there is no formation of the low-melting eutectic between the carbonate and lithium oxide. The partial micromelting does not affect the mechanical properties of the briquette. The selected temperature mode provides the uniform thermal decomposition of lithium carbonate over the whole mass of the briquette, which minimizes the possibility of contacts between the carbonate and lithium oxide. Under these conditions, the time of the total degree of dissociation is 2 h. A decrease in the heating rate leads to an increase in the duration of the dissociation process, while its increase leads to the partial melting of the briquette. Aluminum plays the role of an inert additive accelerating the dissociation process at the stage of dissociation.