Chemical behavior of lithium ions in reexpanded lithium-montmorillonit
es has been investigated, their hydration capacity, interlamellar avai
lability, and thermal reactivity being examined. Two experiments have
been carried out: a thermal treatment to evaluate the possible recolla
pse of the sample, and an ionic exchange with sodium ions followed by
a further thermal treatment to analyze its exchange capacity. Samples
obtained have been characterized by means of XRD, FTIR, DTA/TG, and Si
-29, Al-27, and Li-7 MAS NMR. A complete recollapse of the sample afte
r the thermal treatment and an extensive ionic exchange in NaCl soluti
on were attained. The total reversibility of the process for lithium i
ons has been concluded, although irreversible damage in the silicate l
attice is observed.