Separation of Silver from Liquid Media
Silver is the sixty-sixth most abundant metal in the Earth's crust and used heavily in the photographic, electronic, and ornamental metal industries. In nature, silver is often associated with other metals and, in fact, much of the silver that makes its way into the world market is co-produced as a by-product of the mining processes for other metals like copper, zinc, and lead. Most silver is mined in Mexico, Peru, Canada, Australia, and the United States.
Ion exchange resins are not heavily employed in the conventional mining of silver. The cost to recover the metal from the resin is often not economical considering the current market value of silver. Some smaller gold and platinum facilities employing strongly acidic leach techniques, however, use ion exchange resins to capture ionic silver. Under these conditions of an acidic stream combined with a strong brine, silver forms anionic complexes that can be captured with a strong base anion resin such as AmberSep™ 21K XLT Resin. Additional information about the recovery of precious metals from acidic halogen leach solutions can be found on our Answer Center.
Ion exchange resins are commonly used to remove trace contaminants, including silver. In these applications, recovery is not usually desired, so the resin is treated as a disposable media (according to local regulations). Various cations have different affinities for strong acid cation exchange resins, such as AmberSep™ G26 H Resin.
If the ionic matrix of the stream causes insufficient capture of silver on a strong acid cation resin, a more selective chelating resin like AmberSep 43600 Resin should be considered instead.