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

Devices and methods for purifying lithium from lithium salts, including those with low concentration of lithium salts, are provided. A molten composition comprising a lithium salt is electrolyzed with an anode in contact with the molten composition and a cathode separated from the molten composition by a solid electrolyte capable of conducting lithium ions.

Methods are proposed for fabricating highly pure lithium metal electrodes from aqueous lithium salt solutions by means of electrolysis through lithium ion selective membranes, performed at constant current densities between about 10 mA/cm.sup.2 and about 50 mA/cm.sup.2, and wherein the constant current is applied for a time between about 1 minute and about 60 minutes. The electrolysis is performed under a blanketing atmosphere, the blanketing atmosphere being substantially free of lithium reactive components. Methods are further proposed for vertically integrating the electrolytic fabrication of highly pure lithium metal electrodes into the production of lithium metal batteries, the fabrication of lithium electrodes and lithium metal batteries being performed in a single facility.

An electrochemical cell for producing metal and chlorine from metal ore and a metal chloride includes a cathode, an anode, and a separator. A catholyte includes (i) water, (ii) a metal hydroxide comprising Q, where Q is an alkali metal, an alkaline earth metal, or a combination thereof, and (iii) suspended metal ore particles comprising M.sub.xO.sub.y where M is a metal and x and y are integers. An anolyte includes (i) water and (ii) a metal chloride comprising Q. An electrowinning process for producing metal and chlorine includes applying a voltage across the electrochemical cell to effect reduction of the M.sub.xO.sub.y in the cathode compartment to provide the metal M and oxidation of chloride ions in the anode compartment to form Cl.sub.2 gas.

An electrochemical cell for producing metal and chlorine from metal ore and a metal chloride includes a cathode, an anode, and a separator. A catholyte includes (i) water, (ii) a metal hydroxide comprising Q, where Q is an alkali metal, an alkaline earth metal, or a combination thereof, and (iii) suspended metal ore particles comprising M.sub.xO.sub.y where M is a metal and x and y are integers. An anolyte includes (i) water and (ii) a metal chloride comprising Q. An electrowinning process for producing metal and chlorine includes applying a voltage across the electrochemical cell to effect reduction of the M.sub.xO.sub.y in the cathode compartment to provide the metal M and oxidation of chloride ions in the anode compartment to form Cl.sub.2 gas.

Some embodiments include a molten salt system comprising: a molten salt enclosure; a molten salt disposed within the molten salt enclosure; a working electrode disposed at least partially within the molten salt; a counter electrode disposed at least partially within the molten salt; a separator barrier disposed at least partially within the molten salt; a reference salt disposed within the separator barrier; and a reference wire disposed within the reference salt.

An electrode for electrolytic processes, in particular to an anode suitable for oxygen evolution having a valve metal substrate, a catalytic layer, a protection layer consisting of oxides of valve metals interposed between the substrate and the catalytic layer and an outer coating of oxides of valve metals. The electrode is particularly suitable for processes of cathodic electrodeposition of chromium from an aqueous solution containing Cr (III).

An electrode for electrolytic processes, in particular to an anode suitable for oxygen evolution having a valve metal substrate, a catalytic layer, a protection layer consisting of oxides of valve metals interposed between the substrate and the catalytic layer and an outer coating of oxides of valve metals. The electrode is particularly suitable for processes of cathodic electrodeposition of chromium from an aqueous solution containing Cr (III).

In a method for electrochemical ammunition disposal and material recovery, ammunition cartridges are placed in an acidic aqueous solution that is in contact with a cathode and an anode. The ammunition cartridges have a casing that includes an alloy of copper and zinc. The ammunition cartridges are agitated in the acidic aqueous solution as a voltage is applied between the anode and the cathode. The applied voltage is effective to oxidize and dissolve zinc from the copper-zinc alloy. Copper metal derived from the alloy can be recovered as a solid, and zinc ion derived from the alloy can be recovered as a solution.

In a method for electrochemical ammunition disposal and material recovery, ammunition cartridges are placed in an acidic aqueous solution that is in contact with a cathode and an anode. The ammunition cartridges have a casing that includes an alloy of copper and zinc. The ammunition cartridges are agitated in the acidic aqueous solution as a voltage is applied between the anode and the cathode. The applied voltage is effective to oxidize and dissolve zinc from the copper-zinc alloy. Copper metal derived from the alloy can be recovered as a solid, and zinc ion derived from the alloy can be recovered as a solution.