A method for producing metal chloride Mx+Clx? includes reacting metal carbonate in solid form using phosgene, diphosgene and/or triphosgene to form metal chloride Mx+Clx?, wherein the metal M is selected from the group containing alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, for example, and x corresponds to the valency of the metal cations. An apparatus for performing such method is also disclosed.

A process for preparing metal chloride Mx+Clx?, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx?, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.

A process for preparing metal chloride Mx+Clx?, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx?, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.

The present invention relates to the recovery of rare earths, scandium, niobium, tantalum, zirconium, hafnium, titanium, and the like from ores or concentrates containing fluorine. More specifically, the ores or concentrates are pretreated by carbochlorination to convert the rare earths and other metals into their chlorides and then subjected to dilute hydrochloric acid leaching to recover the valuable rare earths and other metals from the leachate. Niobium, tantalum, zirconium, hafnium, and titanium can be recovered as their chlorides or oxychlorides from the gaseous products of carbochlorination, or converted into their oxides while simultaneously regenerating chlorine.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydrochloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

The present description relates to a process for producing magnesium metal from magnesium-bearing ores using serpentine. The process described herein consists generally in a mineral preparation and classification followed by leaching with dilute hydrochloric acid. The slurry is filtered and the non-leached portion, containing amorphous silica is recovered. The residual solution is neutralized and purified by chemical precipitation with non activated and activated serpentine. The nickel is also recovered by precipitation at higher pH. A final neutralisation and purification step of magnesium chloride solution by precipitation allows eliminating any traces of residual impurities. The purified magnesium chloride solution is evaporated until saturation and the MgCl.sub.2.6H.sub.2O is recovered by crystallization in an acid media. The salt is dehydrated and subsequent electrolysis of anhydrous magnesium chloride produces pure magnesium metal and hydrochloric acid.

A process for preparing metal chloride Mx+Clx, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.

A process for preparing metal chloride Mx+Clx, in which metal carbonate in solid form is reacted with a chlorinating agent selected from chlorine and oxalyl chloride to give metal chloride Mx+Clx, where the metal M is selected from the group of the alkali metals, alkaline earth metals, Al and Zn, Li and Mg, or Li, and x corresponds to the valency of the metal cation, and wherein metal M is additionally added as a reactant to the metal carbonate/chlorinating agent reaction.