A method of recovering a metal from a metal-containing waste material comprises heating a metal-containing waste material under a hydrogen flow to form a hydrided metal material. Hydrogen is removed from the hydrided metal material to form an elemental metal or a metal oxide. Additional methods are disclosed, as are related electrochemical cells.

A method of and system for electrolytic production of reactive metals is presented. The method includes providing a molten oxide electrolytic cell including a container, an anode, and a current collector and disposing a molten oxide electrolyte within the container and in ion conducting contact with the anode and the current collector. The electrolyte includes a mixture of at least one alkaline earth oxide and at least one rare earth oxide. The method also includes providing a metal oxide feedstock including at least one target metal species into the molten oxide electrolyte and applying a current between the anode and the current collector, thereby reducing the target metal species to form at least one molten target metal in the container.

A method for recycling molten salt from electrorefining processes, the method having the steps of collecting actinide metal using a first plurality of cathodes from an electrolyte bath, collecting rare earths metal using a second plurality of cathodes from the electrolyte bath, inserting the collected actinide metal and uranium into the bath, and chlorinating the inserted actinide metal and uranium. Also provided is a system for recycling molten salt, the system having a vessel adapted to receive and heat electrolyte salt, a first plurality of cathodes adapted to be removably inserted into the vessel, a second plurality of cathodes adapted to be removably inserted into the vessel, an anode positioned within the vessel so as to be coaxially aligned with the vessel, and a vehicle for inserting uranium into the salt.

Electrorefining cells and methods for electrorefining ferrous molten metal (e.g. steels), that includes impurities (e.g., carbon), are described. Liquid metal is provided in ladle with a molten electrolyte on top of it to form a metal-electrolyte interface. An electrode connection is put into contact with the metal for electronic conduction therewith, while a counter electrode is put into contact with the electrolyte for forming an electrolyte-counter electrode interface. Both the electrode connection and the counter electrode remain in the solid form in, and inert to, the metal and the electrolyte, respectively. The electrode connection and the counter electrode are made of an electronically conductive material. Therefore, during electrorefining operations, an electromotive force can be supplied between the electrode connection and the counter electrode so as to induce electrochemical reactions to occur at both the metal-electrolyte interface and the electrolyte-counter electrode connection, producing a ferrous molten metal depleted of the impurities.

Methods and systems for use in targeted removal of metals from a substrate via electrorefining are described. A self-propagating reaction is initiated by use of a thermite to reach high temperatures sufficient to induce localized melting of a salt situated on a metal or alloy substrate. Using a power supply connected to an electrode assembly, an electrorefining reaction capable of generating significant localized corrosion of the substrate is produced.

Metals are smelted properly. An electrolytic smelting furnace includes a furnace body, a furnace bottom electrode provided at a bottom part in the furnace body, and an upper electrode provided above the furnace bottom electrode in the furnace body, and the upper electrode includes a conductive compound with a spinel-type structure.

Disclosed herein is an electrolyzer comprising a horizontal cathode located below a suspended anode for purposes of performing electrolysis on metal-bearing mixtures or solutions. The horizontal cathode may comprise the bottom surface of a compartment for containing a mixture or solution of metal components, electrolyte, and/or supplemental chemicals. The horizontal anode may engage the upper surface of the mixture or solution in the compartment. A removal mechanism for facilitating removal of the end-products of the mixture or solution from the compartment (and the surface of the horizontal cathode) through the gate may also be employed. These implementations may be used in recycling of lead acid batteries (LABs) without any need for smelting, and also may be applied to a variety of different electrolytical operations.

Recovery of noble metals (including the recovery of gold and/or silver from gold and/or silver containing material) is generally described. The gold and/or silver can be recovered selectively, in some cases, such that gold and/or silver are at least partially separated from non-silver and/or non-gold material. Gold and/or silver may be recovered from material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and at least one supplemental acid, such as sulfuric acid, phosphoric acid, and/or a sulfonic acid. The amount of nitric acid within the mixture can be, in some instances, relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. In some cases, the recovery of gold and/or silver using the acid mixtures can be enhanced by transporting an electric current between an electrode and the gold and/or silver of the material. In some cases, acid mixtures can be used to recover silver from particular types of materials, such as material comprising silver metal and cadmium oxide and/or material comprising silver metal and tungsten metal.

Recovery of noble metals (including the recovery of gold and/or silver from gold and/or silver containing material) is generally described. The gold and/or silver can be recovered selectively, in some cases, such that gold and/or silver are at least partially separated from non-silver and/or non-gold material. Gold and/or silver may be recovered from material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and at least one supplemental acid, such as sulfuric acid, phosphoric acid, and/or a sulfonic acid. The amount of nitric acid within the mixture can be, in some instances, relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. In some cases, the recovery of gold and/or silver using the acid mixtures can be enhanced by transporting an electric current between an electrode and the gold and/or silver of the material. In some cases, acid mixtures can be used to recover silver from particular types of materials, such as material comprising silver metal and cadmium oxide and/or material comprising silver metal and tungsten metal.

A method of processing a polycrystalline diamond body includes positioning an electrode near the polycrystalline diamond body such that a gap is defined between the electrode and the polycrystalline diamond body, the polycrystalline diamond body having a metallic material disposed in interstitial spaces defined within the polycrystalline diamond body. The method includes applying a voltage between the electrode and the polycrystalline diamond body, and passing a processing solution through the gap. The electrode is a cathode and the polycrystalline diamond body is an anode. An assembly for processing a polycrystalline diamond body includes the polycrystalline diamond body, an electrode positioned such that a gap is defined between the electrode and the polycrystalline diamond body, a processing solution passing through the gap such that the processing solution is in electrical communication with each of the polycrystalline diamond body and the electrode, and at least one power source.