Assertion: lignite | /r/ObjectUse | used as activator
Facets:
value: in this study
type: TEMPORAL
Source sentences:
text: In this study, lignite was used as a raw material for high-temperature graphitization heat treatment after impregnation with an oxidant (H 2 SO 4 ) and an activator (H 3 PO 4 ) to obtain synthetic graphite with a cellular microstructure.