Ion Exchange
also known as IX · resin exchange
Ion exchange passes a solution through a bed of resin whose functional groups hold exchangeable ions. Target metal ions displace those ions and are held on the resin; a subsequent elution step with an acid, base or salt solution releases them into a concentrated, purified stream. Selectivity is set by the resin's functional group and by solution pH.
Why it matters in practice
Ion exchange handles very dilute solutions economically where solvent extraction would need impractically large flows, and it concentrates the metal as well as purifying it. It is the usual choice for recovering trace metals from raffinates and for polishing streams before discharge.
Where this appears on this site
Equipment referenced in this entry
PP Ion Exchange Unit
7 Specifications · ion exchange unit
Pmma Ion Exchange Unit
7 Specifications · ion exchange unit
Related terms
Reference entry GL-ION-EXCHANGE. Definitions on this page describe engineering practice in hydrometallurgical process design; they are not a substitute for test work on your own material.