This disclosure relates to a process for selectively extracting Fe(III) ions from an aqueous feedstock containing Fe(III) ions and non-ferric ions. The process comprises contacting the feedstock with an organic phase comprising a phosphonium salt or ammonium salt ionic liquid under liquid-liquid extraction conditions for a time sufficient to allow transfer of at least some of the Fe(III) ions from the feedstock to the organic phase to provide an Fe(III) ion laden organic phase and an Fe(III) depleted feedstock, and separating the Fe(III) ion laden organic phase from the Fe(III) depleted feedstock.

This disclosure relates to a process for selectively extracting Fe(III) ions from an aqueous feedstock containing Fe(III) ions and non-ferric ions. The process comprises contacting the feedstock with an organic phase comprising a phosphonium salt or ammonium salt ionic liquid under liquid-liquid extraction conditions for a time sufficient to allow transfer of at least some of the Fe(III) ions from the feedstock to the organic phase to provide an Fe(III) ion laden organic phase and an Fe(III) depleted feedstock, and separating the Fe(III) ion laden organic phase from the Fe(III) depleted feedstock.

Methods for removing impurities from precursors and related systems are provided. A method comprises at least one thermal cycle. The at least one thermal cycle comprises one or more of the following steps: heating a vessel comprising a precursor and at least one impurity to a temperature for a duration sufficient to vaporize at least a portion of the at least one impurity; measuring a vapor pressure within the vessel to obtain a measured vapor pressure and comparing the measured vapor pressure to a set point vapor pressure; and when the measured vapor pressure is above or within the set point vapor pressure, removing, from the vessel, at least a portion of a vapor comprising the at least one impurity. Other methods and systems are provided herein.

Methods for removing impurities from precursors and related systems are provided. A method comprises at least one thermal cycle. The at least one thermal cycle comprises one or more of the following steps: heating a vessel comprising a precursor and at least one impurity to a temperature for a duration sufficient to vaporize at least a portion of the at least one impurity; measuring a vapor pressure within the vessel to obtain a measured vapor pressure and comparing the measured vapor pressure to a set point vapor pressure; and when the measured vapor pressure is above or within the set point vapor pressure, removing, from the vessel, at least a portion of a vapor comprising the at least one impurity. Other methods and systems are provided herein.

There are provided processes for purifying aluminum ions. Such processes comprise precipitating the aluminum ions under the form of Al(OH).sub.3 at a first pH range; converting Al(OH).sub.3 into AlCl.sub.3 by reacting Al(OH).sub.3 with HCl and precipitating said AlCl.sub.3; and heating the AlCl.sub.3 under conditions effective for converting AlCl.sub.3 into Al.sub.2O.sub.3 and optionally recovering gaseous HCl so-produced. The processes can also comprise converting alumina into aluminum.

The present invention relates to a process for electrolytic production of aluminium from aluminium chloride, in an electrolysis cell with an electrolyte, where the aluminium chloride is produced by chlorination of an aluminium containing feedstock using chlorine gas and a carbonaceous reducing agent, CO and/or phosgene. The produced aluminium chloride is led to an absorption unit and partly absorbed by a molten salt liquid where some of the molten salt liquid in the absorption unit, enriched with aluminium chloride by the absorption, is transferred to the electrolysis cell wherein the aluminium chloride is electrolytically converted to aluminium metal and chlorine gas. The gases that are not absorbed by the liquid is led out of the absorption unit. The invention also relates to an apparatus for operating the process.