| Classification |
Dry Recovery |
Metal Substitution |
Chemical Reduction |
Electrochemical
Recovery |
Purity of Recovered
Precious Metal |
50~90% |
95~98% |
99.9% |
99.99% |
| Purification Method |
Using organic
incineration and the
difference of melting
point. |
Metal substitution (Cu, Al and so
on) by the difference of
ionization tendency. |
Reducing capacity of
reagent. |
Recovery by
standard reduction
potential. |
| Merit |
Suitable for the case of
being mixed with
organic materials.
Simple process
(incineration, melting). |
Short recovery L/T
Less wastewater |
Using capacity
of reduction |
Very high purity |
| Demerit |
Difficult to remove the
impurity.
High energy cost. |
Low Ag purity.
Additional purification process is
required.
Need environmental cost. |
Impossible to recover
with high purity.
Generating wastewater
during washing
process
Atmosphere
environmental cost. |
Long purification
L/T.
Requiring repetitive
purification for
specific impurity. |
