A device and a method for preparing pure titanium by electrolysis-chlorination-electrolysis, wherein the device includes a first electrolytic cell, a second electrolytic cell, a chlorination reactor and guide tubes. The Cl.sub.2 generated at the anode of the first electrolytic cell is introduced into a chlorination reactor containing the TiC.sub.xO.sub.y or TiC.sub.xO.sub.yN.sub.z raw materials via a guide tube, and a chlorination is carried out to generate TiCl.sub.4 gas at a temperature of 200° C.-600° C. The TiCl.sub.4 gas passes through a guide tube into a cathode of the second electrolytic cell, and then an electrolysis is performed to obtain the high-purity titanium in the second electrolytic cell. At the same time, the Cl.sub.2 generated at the anode of the second electrolytic cell is recycled into the chlorination reactor in the first electrolytic cell to continue to participate in the chlorination of TiC.sub.xO.sub.y or TiC.sub.xO.sub.yN.sub.z.

A method of making a graphene-containing material comprising the steps of: electrolytically reducing a transition metal oxide to a transition metal in an electrolytic cell using a molten salt electrolyte and a carbon anode; followed by extracting a dry graphene material from the electrolytic cell. Also provided is a graphene-containing material obtainable by the method of the invention.

A method of making a graphene-containing material comprising the steps of: electrolytically reducing a transition metal oxide to a transition metal in an electrolytic cell using a molten salt electrolyte and a carbon anode; followed by extracting a dry graphene material from the electrolytic cell. Also provided is a graphene-containing material obtainable by the method of the invention.

A method for separating metal components from a treatment material containing a silicate and metal elements includes: a reaction step of reacting the treatment material and a molten alkali hydroxide in which bubbles due to water vapor derived from water are generated by heating a hydroxide of an alkali metal or an alkaline-earth metal and the water in a state where the hydroxide and the water coexist, to obtain a reaction product; and a first precipitation step of dissolving the reaction product of the treatment material and the molten alkali hydroxide after the reaction step in water, thereby generating a precipitate containing the metal elements.

A method for separating metal components from a treatment material containing a silicate and metal elements includes: a reaction step of reacting the treatment material and a molten alkali hydroxide in which bubbles due to water vapor derived from water are generated by heating a hydroxide of an alkali metal or an alkaline-earth metal and the water in a state where the hydroxide and the water coexist, to obtain a reaction product; and a first precipitation step of dissolving the reaction product of the treatment material and the molten alkali hydroxide after the reaction step in water, thereby generating a precipitate containing the metal elements.

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.

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 of electrolytic reduction of a feedstock comprising oxygen and a first metal comprises the steps of, arranging the feedstock in contact with a cathode and a molten salt within an electrolysis cell, arranging an anode in contact with the molten salt within the electrolysis cell, the anode comprising a molten second metal and applying a potential between the anode and the cathode such that oxygen is removed from the feedstock to form a reduced feedstock. The oxygen removed from the feedstock reacts with the molten second metal to form an oxide comprising the second metal. The second metal is aluminium. The reduced feedstock may comprise a proportion of aluminium.

A method of electrolytic reduction of a feedstock comprising oxygen and a first metal comprises the steps of, arranging the feedstock in contact with a cathode and a molten salt within an electrolysis cell, arranging an anode in contact with the molten salt within the electrolysis cell, the anode comprising a molten second metal and applying a potential between the anode and the cathode such that oxygen is removed from the feedstock to form a reduced feedstock. The oxygen removed from the feedstock reacts with the molten second metal to form an oxide comprising the second metal. The second metal is aluminium. The reduced feedstock may comprise a proportion of aluminium.

A method of producing metallic tantalum comprises the steps of providing a precursor comprising a tantalate of a first metal, arranging the precursor material in contact with a molten salt in an electrolytic cell, the electrolysis cell further comprising an anode and a cathode arranged in contact with the molten salt, and applying a potential between the anode and the cathode such that the precursor material is reduced to tantalum. The first metal is an alkali metal or an alkaline earth metal. The anode does not comprise a carbon material, which prevents contamination of the tantalum and improves current efficiency of the process.