Assertion: carbon black's carbon | /r/ObjectUse | used in gold purification
Facets:
Source sentences:
text: Activated carbon is used in methane and hydrogen storage, air purification, solvent recovery, decaffeination, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and respirators, filters in compressed air, teeth whitening, production of hydrogen chloride in dark and many other applications.