Abstract: An insoluble anode is for the electrowinning of heavy metals from aqueous solutions which contain them, and for the electrolytic production of oxidizer halogenated salts.The anode includes a copper bar acting as a bus bar (i.e., as a current-bearing bar), having vertical and horizontal holes through which fork-shaped elements, made from a bimetallic conductor, are inserted and fastened. A plurality of fork-shaped elements, made from the filamentary bimetallic conductor, coated by a catalytic layer of Pt and/or PbO.sub.2, act as an electrode with preferential oxygen development. A framework made from an insulating plastics material, is for supporting and stiffening the structure, and for the precise positioning of the anode inside the cell.

Abstract: A process is disclosed for recovering the components of spent lead acid batteries of the type comprising an active mass desulphurization stage in which sodium sulphate is formed, characterized in that the sodium sulphate solution thus formed is fed to an electrolysis stage in which a soda solution is produced at the cathode and a sulphuric acid solution is produced at the anode. The soda solution produced at the cathode is recycled to the active mass desulphurization stage, and the sulphuric acid solution produced at the anode is recovered for reuse as battery electrolyte in the production of new lead acid batteries.

Abstract: A process for producing electrolytic lead and elemental sulfur from galena comprises the steps of leaching galena with an acidic aqueous solution of ferric fluoborate, with ferrous fluoborate, lead fluoborate, and elemental sulfur being formed according to the reaction:2 Fe(BF.sub.4).sub.3 +PbS.fwdarw.2 FE(BF.sub.4).sub.2 +Pb(BF.sub.4).sub.2 +S.In a further step, a solid residue produced in the leaching step is filtered off, the solid residue comprising elemental sulfur and galena gangue. The solution of ferrous fluoborate and lead fluoborate formed in the leaching step is subjected to electrolysis in a diaphragm electrolytic cell in which pure lead is deposited at a cathode of the cell and ferrous ions are oxidated to ferric ions at an anode of the cell. A solution of ferric fluoborate regenerated at the anode in the electrolysis step is recycled to the leaching step so that the solution is subjected to the galena leaching step.

Abstract: An electrical conductor is particularly suitable for use as an insoluble anode in electrowinning processes, and is composed of an inner core of copper coated with an outer, thinner layer of a transition metal, preferably selected from among tantalum, titanium and niobium. The conductor is manufactured by a process including the steps of inserting a copper bar inside a relatively thin tube made of the selected transition metal, inserting the tube containing the copper bar inside a copper tube to obtain a three-metal structure, submitting the three-metal structure to a drawing process to produce a three metal wire, and dipping the three-metal wire in a solvent to remove the outer copper layer to produce a bimetallic wire.

Abstract: The present invention relates to a process and a plant for the processing of saline slag from the melting of aluminium scrap and waste with a saline flux in which the salts constituting the flux are recovered and other components of the slag are separated. The harmful or toxic gases developed during this processing are subjected to combustion to produce flue gases dispersible in the atmosphere with recovery of combustion heat, preferably used over in processing the slag.

Abstract: A process for recovering in pure metal form substantially all lead from battery sludge is disclosed. The battery sludge is desulfurized, leached with acid, and separated by filtration. Lead is recovered from the filtrate by electrowinning. The residue from the leaching and filtration is treated with concentrated sulfuric acid to cause the simultaneous occurring of the following reactions:C.sub.n (H.sub.2 O).sub.m +H.sub.2 SO.sub.4 .fwdarw.nC+H.sub.2 SO.sub.4 .multidot.mH.sub.2 O (1)C+2PbO.sub.2 +2H.sub.2 SO.sub.4 .fwdarw.2PbSO.sub.4 +CO.sub.2 +2H.sub.2 O (2)up to the quantitative reduction of substantially all of the lead dioxide PbO.sub.2 and elimination of substantially all the organic substances C.sub.n (H.sub.2 O).sub.m contained in the insoluble residue. Lead sulfate from the above reaction is recycled to the desulfurization step.

Abstract: The invention relates to a hydrometallurgical process for the overall recovery of the components of exhausted lead-acid batteries, in a re-useable form, said components being mainly constituted by such materials as polypropylene, ebanite, PVC; by paste comprising lead sulphatized compounds; and by pure or alloyed metal lead, characterized in that it comprises the following steps:(a) battery crushing,(b) separation of paste by wet-screening,(c) separation of polypropylene by water floating,(d) separation of ebanite and PVC from pure or alloyed metal lead, by means of a first hydrodynamic separation,(e) separation of ebanite from PVC by a second hydrodynamic separation,(f) desulfurization of paste by carbonation by sodium carbonate, with pure sodium sulphate being obtained,(g) recovery of so-obtained pure sodium sulphate,(h) treatment of carbonated paste in order to recovery from it the lead, in pure metal form, by extraction by electrowinning.

Abstract: The invention relates to a process which makes possible the scrubbing of the flues and the recovery of the salts as contained in the oven slags for the remelting of aluminum scraps with a saline flux, by washing the slags with water and using the brine thus obtained for scrubbing the flues, until obtaining the saturation and the separation of the salt to be recycled as a flux.