Abstract: The present invention relates to an electrolytic process for producing metallic lead starting from desulfurized lead pastel comprising the following operative phases: a) leaching the desulfurized pastel by putting it in contact with a solution comprising ammonium chloride, with the formation of a leach liquor and evolution of gaseous CO2; b) separating a first solid residue and a first clarified leach liquor from the leach liquor coming from phase a); c) leaching the solid residue separated in phase b) by putting it in contact with a solution comprising ammonium chloride and hydrogen peroxide; d) separating a second solid residue and a second clarified leach liquor from the leach liquor coming from phase c); e) joining the first clarified leach liquor coming from phase b) with the second clarified leach liquor coming from phase d) and forming a single solution; f) subjecting the solution leaving phase e) to electrolysis in a flow cell, with a current density ranging from 50 to 10,000 A/m2, said electrolysis r

Abstract: The present invention relates to an electrolytic process for producing metallic lead starting from desulfurized lead pastel comprising the following operative phases: a) leaching the desulfurized pastel by putting it in contact with a solution comprising ammonium chloride, with the formation of a leach liquor and evolution of gaseous CO2; b) separating a first solid residue and a first clarified leach liquor from the leach liquor coming from phase a); c) leaching the solid residue separated in phase b) by putting it in contact with a solution comprising ammonium chloride and hydrogen peroxide; d) separating a second solid residue and a second clarified leach liquor from the leach liquor coming from phase c); e) joining the first clarified leach liquor coming from phase b) with the second clarified leach liquor coming from phase d) and forming a single solution; f) subjecting the solution leaving phase e) to electrolysis in a flow cell, with a current density ranging from 50 to 10,000 A/m2, said electrolysis r

Abstract: The present invention relates to a process for the recovery of elemental sulphur from residues produced in hydrometallurgical processes based on leaching with a solution of sodium sulphide in which the sulphur contained in the residues is selectively leached as sodium polysulphide. The sulphur leaching solution is conveniently regenerated and recycled to the process.

Abstract: The present invention relates to a desulfurization process of pastel and grids of lead accumulators comprising a carbonation in two steps, a granulometric separation between the two steps followed by specific desulfurization of the large part, a desodification obtaining the conversion of the PbSO4 contained in the pastel into PbCO3 which can be easily converted into metallic Pb in an oven by the addition of coal. The system used for the desodification of the large part of the pastel can also be used for the desulfurization of the fine part of the grids.

Abstract: The present invention relates to a process for the recovery of elemental sulphur from residues produced in hydrometallurgical processes based on leaching with a solution of sodium sulphide in which the sulphur contained in the residues is selectively leached as sodium polysulphide. The sulphur leaching solution is conveniently regenerated and recycled to the process.

Abstract: The present invention relates to a desulfurization process of pastel and grids of lead accumulators comprising a carbonation in two steps, a granulometric separation between the two steps followed by specific desulfurization of the large part, a desodification obtaining the conversion of the PbSO4 contained in the pastel into PbCO3 which can be easily converted into metallic Pb in an oven by the addition of coal. The system used for the desodification of the large part of the pastel can also be used for the desulfurization of the fine part of the grids.

Abstract: The present invention relates to a process for recovering metals, in particular precious metals, from electronic scrap, comprising a leaching phase in which the electronic scrap is treated with a leaching solution based on cupric chloride and an alkaline chloride to dissolve the metals exposed to said solution, with the exception of gold, and a subsequent recovery phase of gold in solid form.

Abstract: A process is disclosed for treating lead paste from exhausted batteries. Calcium sulfite and calcium thiosulfite are formed by the reaction:3Ca(OH).sub.2 +4S.degree..fwdarw.2CaS+CaS.sub.2 O.sub.3 +3H.sub.2 O(1).The CaS and CaS.sub.2 O.sub.3 is reacted with sodium sulfate to effect the double exchange reaction:2CaS+CaS.sub.2 O.sub.3 +3Na.sub.2 SO.sub.4 .fwdarw.2Na.sub.2 S+Na.sub.2 S.sub.2 O.sub.3 +3CaSO.sub.4 (2).The sodium sulfide and sodium thiosulfate is then reacted with the lead paste for converting the various lead paste components (PbSO.sub.4, PbO and PbO.sub.2) into PbS with the concomitant production of sodium sulfate. The sodium sulfate can be recycled to reaction (2).