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.

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.

There is provided a method of electrochemically reducing multiple metal oxide pellets simultaneously, the method comprising: contacting an anode and a cathode with multiple metal oxide pellets with an electrolyte, wherein the multiple metal oxide pellets are secured to the cathode; and applying an electrical potential between the anode and the cathode to reduce multiple metal oxides comprised in the multiple metal oxide pellets to its respective metals. There is also provided an electrochemical cell for electrochemically reducing multiple metal oxide pellets simultaneously.

Disclosed are anodes for an electrochemical reduction system, such as for the electrochemical reduction of oxides in systems using molten salt electrolytes. The anodes comprise a rod or plate formed of and include at least one alloy of at least one transition metal and at least one platinum group metal. The alloy anodes may be less expensive than anodes formed solely from platinum group metals and may exhibit less material attrition than anodes formed solely from transition metals. Related methods and electrochemical reduction systems are also disclosed.

Disclosed is an electrochemical method for high-temperature molten salt electrolysis in humid atmosphere. The method involves preparing hydrogen gas, metals/alloys, metal oxide compounds and metal hydrides in humid high-temperature molten salt environment. Hydrogen gas is generated by electrolyzing water in a molten salt electrolyte at above 100 C., and with a working cathode being a solid-state oxide pellet and a voltage applied to the electrolyzing cell being far lower than that in a direct electro-deoxidation process, the hydrogen gas generated reduces solid-state oxide cathodes to produce metals. The hydrogen ions in the molten salt can be prepared by hydrolysis reaction of the molten salt in a water vapor containing atmosphere. Corresponding metals or alloys or metal oxide compounds can be prepared by reducing iron oxide, molybdenum oxide, tantalum oxide, nickel oxide, copper oxide, titanium oxide or corresponding compound oxides and the like.

Disclosed is an electrochemical method for high-temperature molten salt electrolysis in humid atmosphere. The method involves preparing hydrogen gas, metals/alloys, metal oxide compounds and metal hydrides in humid high-temperature molten salt environment. Hydrogen gas is generated by electrolyzing water in a molten salt electrolyte at above 100 C., and with a working cathode being a solid-state oxide pellet and a voltage applied to the electrolyzing cell being far lower than that in a direct electro-deoxidation process, the hydrogen gas generated reduces solid-state oxide cathodes to produce metals. The hydrogen ions in the molten salt can be prepared by hydrolysis reaction of the molten salt in a water vapor containing atmosphere. Corresponding metals or alloys or metal oxide compounds can be prepared by reducing iron oxide, molybdenum oxide, tantalum oxide, nickel oxide, copper oxide, titanium oxide or corresponding compound oxides and the like.

In a method for removing a substance from a feedstock comprising a solid metal or a solid metal compound, the feedstock is contacted with a fused-salt melt. The fused-salt melt contains a fused salt, a reactive-metal compound, and a reactive metal. The fused salt comprises an anion species which is different from the substance, the reactive-metal compound comprises the reactive metal and the substance, and the reactive metal is capable of reaction to remove at least some of the substance from the feedstock. A cathode and an anode contact the melt, and the feedstock contacts the cathode. An electrical current is applied between the cathode and the anode such that at least a portion of the substance is removed from the feedstock. During the application of the current, a quantity of the reactive metal in the melt is maintained sufficient to prevent oxidation of the anion species of the fused salt at the anode. The method may advantageously be usable for removing the substance from successive batches of the feedstock, where the applied current is controlled such that the fused-salt melt after processing a batch contains the quantity of the reactive metal sufficient to prevent oxidation of the anion species at the anode.

In a method for removing a substance from a feedstock comprising a solid metal or a solid metal compound, the feedstock is contacted with a fused-salt melt. The fused-salt melt contains a fused salt, a reactive-metal compound, and a reactive metal. The fused salt comprises an anion species which is different from the substance, the reactive-metal compound comprises the reactive metal and the substance, and the reactive metal is capable of reaction to remove at least some of the substance from the feedstock. A cathode and an anode contact the melt, and the feedstock contacts the cathode. An electrical current is applied between the cathode and the anode such that at least a portion of the substance is removed from the feedstock. During the application of the current, a quantity of the reactive metal in the melt is maintained sufficient to prevent oxidation of the anion species of the fused salt at the anode. The method may advantageously be usable for removing the substance from successive batches of the feedstock, where the applied current is controlled such that the fused-salt melt after processing a batch contains the quantity of the reactive metal sufficient to prevent oxidation of the anion species at the anode.

Systems and methods for recovery of gaseous substances from molten salt electrolysis are generally described. Certain systems comprise a cell configured for molten salt electrolysis; a collector fluidically connected to the cell and configured to collect volatilized molten salt from the cell; and a gas scrubber fluidically connected to the collector and configured to at least partially remove a gas from an effluent stream of the cell. Some methods comprise, using a pressure gradient: transporting a gas comprising molten salt vapor from an electrolytic cell to and through a collector such that at least a portion of the molten salt vapor forms a solid within the collector; and transporting some or all of the gas from the collector through a gas scrubber.

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.