Abstract: The invention relates to plant (1) and to a method for regenerating sand from foundry cores and moulds by calcination in a fluidized-bed furnace (2), the main characteristic of which lies in the fact that the fumes leaving the calcining furnace are used to heat a current of air which is then used, in its turn, to heat the sand to be treated at its inlet to the calcining furnace, and in that the current of air cooled by the sand to be treated is then heated by means of the purified sand leaving the calcining furnace and is then used as combustion air in the calcining furnace.