An equilibrium study of the chloride and nitrate systems of praseodymium and neodymium with tributyl phosphate and acid

Effects of Simulated Rare Earth Recycling Wastewaters on Biological Nitrification

“…It is well established in the literature that TBP forms neutral complexes with REE with the general formula REEA m TBP n where A is an anion, and values for m and n depend on the chemical solvation mechanism for REE extraction in a specific system. − Such complexes play a key role in extraction-based separation processes. One of the dominant anions in the media studied here that also could potentially take part in a complex with TBP is chloride.…”

The chemistry of lanthanide extraction from aqueous chloride, nitrate, and perchlorate solutions for the extractant di-(2-ethylhexyl) phosphoric acid

“…If two lanthanid.es, M and K, are present simultaneously in a system satisfying the restrictions noted above, then by an approach similar to that of other authors (lU, 15,18), the thermodynamic separation factor may be defined as : …”

“…Several of the equilibrium organic phases, which had been carefully centrifuged to remove entrained aqueous, were found (by the brown ring test) to contain nitrate. ed previously by Goto (l4) and Gray (15), contains r,n activity coefficient term, an aqueous ligand-dependent term, and a term involving organic properties. However, the latter term for the case of simultaneous reac tions is more complex than those of the single-reaction expressions, and is actually the sum of two terms, one for each reaction.…”