Assertion: impurity | /r/HasProperty | copper
Facets:
value: especially
type: DEGREE
value: usually
type: DEGREE
Source sentences:
text: The impurities may be copper or other metals, such as nickel, zinc, chromium, molybdenum, and tungsten that had dissolved from the material to be plated.
text: The impurity is usually copper, and copper can be effectively removed from plating solution.
text: As stated above, impurities, especially copper, can be removed from the plating solution through removal of precipitates by adding benzenesulfonic acid.