Valuable metals, and especially copper and silver, are recovered from a lead containing electrolyte in a process in which the electrolyte is fed into an electrochemical polishing reactor that has a high-surface area cathode at which the electrode potential is controlled to so preferentially reduce copper and silver and to form a pre-treated lead-enriched electrolyte that can then be subjected electrochemical lead recovery.

An apparatus, also named transfer box or TB, for conveying an anode assembly outside of an electrolyte cell is described. An apparatus, also named cell preheater lifting beam or CPLB, for conveying an anode assembly or a cell pre-heater outside of an electrolyte cell is also disclosed. TB and CPLB are conjointly used for starting up the electrolytic cell or for replacing a spent anode assembly while maintaining the production of non-ferrous metal, such as aluminum or aluminium. The thermal insulation of the TB allows maintaining the anode temperature homogeneity and preventing thermal shocks when introducing the inert anodes into the hot electrolytic bath. TN and CPLB allow accurate positioning of anode assemblies or cell-preheaters over the electrolysis cell before achieving mechanical and electrical connections of the anode assembly or the cell pre-heater to the electrolysis cell. Several related methods for the operation of an electrolytic cell are also disclosed.

An apparatus, also named transfer box or TB, for conveying an anode assembly outside of an electrolyte cell is described. An apparatus, also named cell preheater lifting beam or CPLB, for conveying an anode assembly or a cell pre-heater outside of an electrolyte cell is also disclosed. TB and CPLB are conjointly used for starting up the electrolytic cell or for replacing a spent anode assembly while maintaining the production of non-ferrous metal, such as aluminum or aluminium. The thermal insulation of the TB allows maintaining the anode temperature homogeneity and preventing thermal shocks when introducing the inert anodes into the hot electrolytic bath. TN and CPLB allow accurate positioning of anode assemblies or cell-preheaters over the electrolysis cell before achieving mechanical and electrical connections of the anode assembly or the cell pre-heater to the electrolysis cell. Several related methods for the operation of an electrolytic cell are also disclosed.

An apparatus, also named transfer box or TB, for conveying an anode assembly outside of an electrolyte cell is described. An apparatus, also named cell preheater lifting beam or CPLB, for conveying an anode assembly or a cell pre-heater outside of an electrolyte cell is also disclosed. TB and CPLB are conjointly used for starting up the electrolytic cell or for replacing a spent anode assembly while maintaining the production of non-ferrous metal, such as aluminum or aluminium. The thermal insulation of the TB allows maintaining the anode temperature homogeneity and preventing thermal shocks when introducing the inert anodes into the hot electrolytic bath. TN and CPLB allow accurate positioning of anode assemblies or cell-preheaters over the electrolysis cell before achieving mechanical and electrical connections of the anode assembly or the cell pre-heater to the electrolysis cell. Several related methods for the operation of an electrolytic cell are also disclosed.

An environmentally friendly (e.g. no acid, base, or cyanide) system and process for large scale extraction of metal ion into aerobic molten salt (or ionic liquid) and the electrodeposition of metal (e.g. copper, gold, silver, etc.) from the metal ion dissolved in the molten salt. The non-volatile low vapor pressure liquid salt is reusable, and heat from the molten slag can heat the molten salts or ionic liquids. Another embodiment comprises a one-pot apparatus for the extraction of metal (e.g. copper) from metal earths and electrodepositing the metal using a low melting (209° C.) aerated Na—K—Zn chloride salt in which copper metal oxidizes and is converted to soluble copper chloride. When an electrical power supply is connected to the graphite vessel (cathode) and to copper rods in the melt (anodes), then the copper chloride is deposited as copper metal by electroreduction on the bottom of the graphite reaction vessel.

A filter press device for electrolytic production of metal for electrodeposition of metal from solutions, constructed from a plurality of cells connected electrically and hydraulically in series. Each has alternating frames and ion-exchange membranes to form alternating anode and cathode compartments, allowing the free path of liquid. Anolyte or catholyte passes through each compartment. The electrolyzed product is discharged from the compartment in the form of metal or a metallic compound. The electrodes are designed with a vertical base plate acting as an anode with the respective anolyte in a cell unit and in the other, acting as a cathode with the respective catholyte in the adjacent cell unit. Completed the production cycle, the device is stopped, the cell is opened, allowing the metal deposition electrodes, cathodes, can be removed and replaced to start a new productive cycle or remain in place with automatic detachment of metal product.

A filter press device for electrolytic production of metal for electrodeposition of metal from solutions, constructed from a plurality of cells connected electrically and hydraulically in series. Each has alternating frames and ion-exchange membranes to form alternating anode and cathode compartments, allowing the free path of liquid. Anolyte or catholyte passes through each compartment. The electrolyzed product is discharged from the compartment in the form of metal or a metallic compound. The electrodes are designed with a vertical base plate acting as an anode with the respective anolyte in a cell unit and in the other, acting as a cathode with the respective catholyte in the adjacent cell unit. Completed the production cycle, the device is stopped, the cell is opened, allowing the metal deposition electrodes, cathodes, can be removed and replaced to start a new productive cycle or remain in place with automatic detachment of metal product.

The present invention provides a molten-salt electrolytic refining apparatus for refining a raw-material alloy containing indium using a molten-salt electrolytic refining method. The molten-salt electrolytic refining apparatus includes a reaction crucible provided in a reaction container so as to be filled with a molten-salt electrolytic solution, an anode and a cathode immersed in the molten-salt electrolytic solution, an anode crucible in which a liquid raw-material alloy is contained, a cathode crucible in which at least one raw-material metal included in the raw-material alloy is recovered in a liquid phase, and a heater provided so that the temperature of the molten-salt electrolytic solution is adjusted to be equal to or greater than the melting temperature of the raw-material alloy. The present invention also provides a molten-salt electrolytic refining method which includes recovering indium (In) from an indium-tin (In—Sn) alloy using a molten-salt electrolytic solution containing fluoride.

A method for producing metallic silver by electro-deposition, including electrolyzing an electrolyte solution containing Ce(NO.sub.3).sub.3 in an anode zone and an electrolyte solution containing AgNO.sub.3 in a cathode zone by using an electrolytic cell with a specific diaphragm, wherein the electrolyte solution in the anode zone is not allowed to enter the cathode zone. After the electrolyzing is complete, the metallic silver with a high purity is obtained at the cathode, and a Ce.sup.4+-containing solution is obtained in the anode zone.

A method for producing metallic silver by electro-deposition, including electrolyzing an electrolyte solution containing Ce(NO.sub.3).sub.3 in an anode zone and an electrolyte solution containing AgNO.sub.3 in a cathode zone by using an electrolytic cell with a specific diaphragm, wherein the electrolyte solution in the anode zone is not allowed to enter the cathode zone. After the electrolyzing is complete, the metallic silver with a high purity is obtained at the cathode, and a Ce.sup.4+-containing solution is obtained in the anode zone.