Patent ID: 7772452

Claim:
Process for recovery of the silica present in the separators located between the elements of lead-acid batteries, characterized in that it comprises the following operations: a) washing heavy plastics to remove the lead compounds and other foreign bodies, b) separating the heavy plastics from a washing solution, c) lead recovery and regeneration of the washing solution, d) rinsing of the heavy plastics, e) drying of the heavy plastics, f) separation of granular plastics from thin plastics, the latter including polyethylene with silica filler, PVC, and fabrics, g) separation of the PVC and fabrics from the polyethylene with silica filler through fragmentation, h) pyrolysis of the polyethylene with silica filler, i) cracking of the pyrolysis gases and vapours in order to reduce their molecular weight and render them more suitable for handling and combustion to provide the heat necessary for pyrolysis, j) oxidation of the pyrolysis residue to remove carbonaceous residues and recover the silica, k) pyrolysis of the mixture of PVC and fabrics in the presence of alkaline substances, and l) oxidation of the residue from the pyrolysis of PVC and fabrics with the production of inert ashes.