The present description relates to a process for extracting magnesium compounds from magnesium-bearing ores comprising leaching serpentine tailing with dilute HCl to dissolve the magnesium and other elements like iron and nickel. The residual silica is removed and the rich solution is further neutralized to eliminate impurities and recover nickel. Magnesium chloride is transformed in magnesium sulfate and hydrochloric acid by reaction with sulfuric acid. The magnesium sulfate can be further decomposed in magnesium oxyde and sulphur dioxyde by calcination. The sulphur gas can further be converted into sulfuric acid.

Methods separates a gas comprising providing a first electrode in ion-conducting contact with an electrolyte, providing a second electrode in ion-conducting contact with the electrolyte, wherein the second electrode comprises a liquid metal, providing a displacing material comprising a first surface in contact with the second electrode and a second surface exposed to an environment outside the second electrode, wherein said material permits flow of gas and impedes flow of liquid metal, and establishing a potential between the first and second electrodes, whereby gas flows toward the liquid metal. Other aspects include methods and apparatuses comprising electrodes, electrolytes and displacing materials.

Provided is a method for producing metal by molten salt electrolysis, by which the metal can be efficiently produced. A method for producing metal by using an apparatus for molten salt electrolysis having an electrolytic cell and an electrode pair, wherein the molten salt electrolysis in the electrolytic cell and heating of the molten salt by a Joule heat generation between a pair of electrodes for electrolysis are simultaneously performed; and wherein the apparatus for molten salt electrolysis has at least two sets of electrode pair, and at least one set of the electrode pairs is electrically opened.

Provided is a method for producing metal by molten salt electrolysis, by which the metal can be efficiently produced. A method for producing metal by using an apparatus for molten salt electrolysis having an electrolytic cell and an electrode pair, wherein the molten salt electrolysis in the electrolytic cell and heating of the molten salt by a Joule heat generation between a pair of electrodes for electrolysis are simultaneously performed; and wherein the apparatus for molten salt electrolysis has at least two sets of electrode pair, and at least one set of the electrode pairs is electrically opened.

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.

A molten salt electrolyzer having a metal collection chamber, an electrolysis chamber, and two or more electrolytic cell units positioned in the electrolysis chamber. Each electrolytic cell unit has a cathode having an inner space in a prism form; at least one bipolar electrode in a rectangular cylinder form and disposed in the cathode inner space; and an anode in a prism form and disposed in an inner space of the bipolar electrode. At least part of individual planes forming an outer side of the bipolar electrode closest to the cathode faces a plane forming the prism-form inner space of the cathode. At least part of individual planes forming the inner side of the bipolar electrode closest to the anode faces a plane forming the prism of the anode. At least one plane of the cathode constitutes one plane of a cathode of another electrolytic cell unit.

A molten salt electrolyzer having a metal collection chamber, an electrolysis chamber, and two or more electrolytic cell units positioned in the electrolysis chamber. Each electrolytic cell unit has a cathode having an inner space in a prism form; at least one bipolar electrode in a rectangular cylinder form and disposed in the cathode inner space; and an anode in a prism form and disposed in an inner space of the bipolar electrode. At least part of individual planes forming an outer side of the bipolar electrode closest to the cathode faces a plane forming the prism-form inner space of the cathode. At least part of individual planes forming the inner side of the bipolar electrode closest to the anode faces a plane forming the prism of the anode. At least one plane of the cathode constitutes one plane of a cathode of another electrolytic cell unit.

The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.

The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.