The invention relates to a melted and cast refractory product having a chemical composition such that, in mass percentages on the basis of the oxides: AI.sub.2O.sub.3: complement up to 100%; MgO: 26% to 50%; ZrO.sub.2: 0.5% to 10.0%; B.sub.2O.sub.3: <1.5%; SiO.sub.2: 0.5%; Na.sub.2O+K.sub.2O: 0.3%; CaO: 1.0%; Fe.sub.2O.sub.3+TiO.sub.2: <0.55%; other oxide species: <1.0%. In said product, the elementary mass ratio R of the zirconium content to the total boron, fluorine and silicon content is between 2 and 80.

A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

The present technology provides a process comprising: contacting a hydrocarbon feedstock with an effective amount of sodium metal and an effective amount of exogenous capping agent at a temperature of 250-500 C., to produce a mixture of sodium salts and a converted feedstock, wherein the hydrocarbon feedstock comprises hydrocarbons with a sulfur content of at least 0.5 wt % and an asphaltene content of at least 1 wt %; the sulfur content comprises asphaltenic sulfur and non-asphaltenic sulfur; the converted feedstock comprises hydrocarbon oil with a sulfur content less than that in the hydrocarbon feedstock and an asphaltene content less than that in the hydrocarbon feedstock; and the proportion of asphaltenic sulfur to non-asphaltenic sulfur in the converted feedstock is lower than in the hydrocarbon feedstock.

A device and a method for metal preparation by electro-reduction of a molten salt are provided. The device includes a reactor, an electrical conductor, a power supply, a gas charging and discharging mechanism, and a closure mechanism; the reactor is a barrel body with a conductive base plate and an insulated peripheral wall and opens at one end, a barrel cavity of the reactor is configured to lay down a reactant and a molten salt substance; the electrical conductor is configured to be inserted into the molten salt substance; the reactor and the electrical conductor are disposed inside the closure mechanism; a positive pole of the power supply is electrically connected to the electrical conductor, and a negative pole is electrically connected to the conductive base plate; the gas charging and discharging mechanism is configured to continuously charge a protective gas into the reactor while removing an exhaust gas.

Systems and methods for feeding solid material and a gas into a container (e.g., electrolytic cell) are generally described. Certain methods comprise feeding solid material and a gas into an electrolytic cell through an inlet; wherein: the gas comprises an inert gas; and the inlet is positioned, relative to an anode of the electrolytic cell, within a distance that is less than or equal to 5 times the shortest cross-sectional dimension of the anode. Certain systems comprise a container configured for molten salt electrolysis; a passageway configured for feeding solid material and a gas into the container; an anode; a cathode; and an outlet configured for releasing a gas from the container; wherein an inlet from the passageway to the container is positioned, relative to the anode, within a distance that is less than or equal to 5 times the shortest cross-sectional dimension of the anode.

Molten oxide electrolysis may be used for extracting one or more metals from a mixture of metal oxides. The mixture of metal oxides may be complex and include at least three metal oxides, each present at 0.5 wt % or greater based on a total weight of the metal oxide electrolyte precursor, to produce a metal oxide electrolyte. In some instances, two or more metals may be extracted in a series of molten oxide electrolysis process where metal oxides having higher Gibbs free energy of formation at 1500 C. are preferentially reduced in each respective molten oxide electrolysis unit before metal oxides having lower Gibbs free energy of formation at 1500 C.

Methods and systems for purifying metals or metal alloys are provided. The method comprises disposing a molten material comprising predominantly aluminum and at least one first metal having an atomic mass less than 13 in a first region of an electrolysis cell. The electrolysis cell comprises an anode, a cathode, and a molten salt electrolyte in contact with the anode and the cathode. The method comprises contacting the anode with the molten material, and applying an electrical voltage across the anode and the cathode such that at least a portion of the first metal in the molten material migrates to a third region in the electrolysis cell to produce a first material enriched in the first metal. The method comprises removing at least a first portion of the first material in the third region from the electrolysis cell.

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.

Molten oxide electrolysis may be used for extracting one or more metals from a mixture of metal oxides. The mixture of metal oxides may be complex and include at least three metal oxides, each present at 0.5 wt % or greater based on a total weight of the metal oxide electrolyte precursor, to produce a metal oxide electrolyte. In some instances, two or more metals may be extracted in a series of molten oxide electrolysis process where metal oxides having higher Gibbs free energy of formation at 1500 C. are preferentially reduced in each respective molten oxide electrolysis unit before metal oxides having lower Gibbs free energy of formation at 1500 C.

The present invention relates to a method of recovering one or more metal species from a raw material, such as waste lithium-ion battery material comprising: providing a molten salt comprising at least one metal hydroxide, providing one or more oxoacidity agents, preferably as a reservoir of one or more oxoacidity agents being in communication with the molten salt, setting the oxoacidity of the molten salt with the one or more oxoacidity agents to an oxoacidity value to dissolve at least one metal species in the molten salt, contacting the raw material with the molten salt, performing at least one of the steps b) and c): b) setting an electrical potential of the molten salt to recover a first metal species to a first metal or first metal oxide, c) adjusting the oxoacidity of the molten salt with the one or more oxoacidity agents to precipitate a first metal oxide, d) optionally performing, for one or more further metal species, the method step a) and/or performing at least one of the method steps b) and c).