Abstract: Systems and methods for selectively recovering a target metal from an ion exchange resin are generally described. In certain embodiments, such methods and systems can be employed for metal purification and enrichment of target metal species from mixtures containing contaminating or non-target metals. In some embodiments, ion exchange is accomplished in the presence of one or more species that facilitate the recovery of a metal from a composition further comprising one or more other metals. The recovered metal-containing composition may contain the recovered metal at relatively high purity and/or in relatively large amounts. In some embodiments, the conditions present during ion exchange are varied in a manner that facilitates the enrichment of a metal from an initial (e.g.

Abstract: A method of recovering rare earth elements from a rare earth-containing material comprises contacting the rare earth-containing material with a solution formulated and configured to dissolve rare earth elements from the rare earth-containing material and form a solution including a plurality of rare earth elements dissolved therein. The method further includes exposing the solution including the plurality of rare earth elements dissolved therein to one of a liquefied gas or a supercritical fluid to isolate the rare earth elements from each other. Related methods of removing and purifying rare earth elements from materials and phosphor lamps are also disclosed.

Abstract: A method of recovering rare earth elements from a rare earth-containing material comprises contacting the rare earth-containing material with a solution formulated and configured to dissolve rare earth elements from the rare earth-containing material and form a solution including a plurality of rare earth elements dissolved therein. The method further includes exposing the solution including the plurality of rare earth elements dissolved therein to one of a liquefied gas or a supercritical fluid to isolate the rare earth elements from each other. Related methods of removing and purifying rare earth elements from materials and phosphor lamps are also disclosed.

Abstract: A method for the electrochemical synthesis of dinitro compounds is disclosed. The method comprises using an anode to oxidize an inactive chemical mediator, such as a ferrocyanide (Fe(CN)6?4) ion, to an active chemical mediator or oxidizing agent, such as a ferricyanide (Fe(CN)6?3) ion, in the presence of a differential voltage. The oxidizing agent reacts with a nitro compound and a nitrite ion to form a geminal dinitro compound. The anode may continuously oxidize ferrocyanide to regenerate active ferricyanide, thus keeping sufficient amounts of ferricyanide available for reaction.

Abstract: A method for the electrochemical synthesis of dinitro compounds is disclosed. The method comprises using an anode to oxidize an inactive chemical mediator, such as a ferrocyanide (Fe(CN)6?4) ion, to an active chemical mediator or oxidizing agent, such as a ferricyanide (Fe(CN)6?3) ion, in the presence of a differential voltage. The oxidizing agent reacts with a nitro compound and a nitrite ion to form a geminal dinitro compound. The anode may continuously oxidize ferrocyanide to regenerate active ferricyanide, thus keeping sufficient amounts of ferricyanide available for reaction.