The solvent extraction-electrowinning technology has improved over time.
Approximately 2.2 million tons of high-quality copper were produced using
this technology in the year 2000. Table 1 shows the advancement of this
technology, which includes how the solvent that extracts the copper has
changed.
Which property of the solvent may be a limitation of the advancement of
this technology in the future?
Table 1. Changes in Solvent Technology over Time
1965
Property
Ability of solvent to remove
copper ions from acid
Separation of copper ions
from iron ions
Speed of copper ion removal
Stability against
decomposition
Generation of impurities
Ability to chemically modify
solvent to extract different
metal ions
Poor
Poor
Slow
Excellent
Medium
Poor
1970
Poor
Good
Medium
Excellent
Low
Fair
1980
Good Excellent
Fast
Good Excellent
Good
1 point
Medium
2000
Good
Fast
Poor
Low
Excellent