Patent ID: 7604785

Claim:
A process for the production of elemental sulphur from residues produced in hydrometallurgical processes comprises: a) leaching of residues containing sulphur with a solution of sodium sulphide wherein the sulphur contained in said residues is selectively leached as sodium polysulphide; b) separation of the residues from the solution containing polysulphide; c) treatment of said solution containing polysulphide with CO 2 to obtain a dispersion containing elemental sulphur, acid sodium polysulphide and sodium bicarbonate; d) separation and recovery of the elemental sulphur from the solution containing acid sodium polysuiphide and sodium bicarbonate; e) treatment of said solution of acid sodium polysulphide and sodium bicarbonate with CaO for regenerating the leaching solution; f) separation of a residue of CaCO 3 from a solution of sodium sulphide which is recirculated to phase a) of the process.