Abstract: A plant (10) for the production of highly flexible and relatively thin sheets or panels (38) of agglomerate material comprising: a mixer crusher (12), a hopper (15) designed to accept the crushed and rolled material (24) and to transfer it to a distributor or spreader (16) positioned below the hopper, said spreader (16) comprising a substantially cylindrical container (30) with a loading opening (31), adjacent, in use, to said hopper (15) and comprising a discharge slot (32) on the opposite side to said opening (31), and a mixing device of the agglomerate material (24) inside said container (30). The mixing device comprises a pair of blades (35) fixed to a shaft (34) rotating around an axis not corresponding to that of said container (30) and in particular offset towards said slot (32), so that during their rotation the blades almost skim said slot.