N. Ezawa et al., Extraction and recovery of precious metals from plating solutions using molecular recognition technology, T I MET FIN, 78, 2000, pp. 238-242
Conventional techniques for recovery of gold from dragout, plating, or stri
pping solutions, produce a gold product that must first be refined, and the
n converted back into potassium gold cyanide (PGC) fore re-use. This proced
ure results in subsequent refining and conversion charges. With the molecul
ar recognition technology (MRT) process, the gold can be directly extracted
and converted to the form of potassium gold cyanide, resulting in substant
ial savings through elimination of the various costs and controls associate
d with gold refining. The recovered gold does not have to be remanufactured
in the form of PGC, and can be quickly recycled. The PGC is deposited on t
he SuperLib(R) resin material, and can then be readily stripped into a conc
entrated aqueous solution for recycling. Results of tests on a commercial g
old electroplating line are presented. Results of work conducted on recover
y of palladium from a dipping bath of palladium/tin chloride catalyst solut
ion are also reviewed.