Assertion: fluorine's compound | /r/ObjectUse | used a flux agent
Facets:
value: historically
type: TEMPORAL
value: in welding
type: LOCATION
Source sentences:
text: Compounds of the element have been used historically a flux agent, designed to make metal and slag more fluid during the smelting process.
text: Compounds of fluorine have historically been used as a flux agent in welding.