Assertion: metal's ore | /r/HasProperty | smelted
Facets:
value: usually
type: DEGREE
Source sentences:
text: When a metal ore is an ionic compound of that metal and a non-metal, the ore must usually be smelted—heated with a reducing agent—to extract the pure metal.
text: The ores involved need to be smelted, roasted, and then leached with sulfuric acid to produce a residue of PGM.
text: When a metal ore is an ionic compound of that metal and a non-metal, the ore must usually be smelted—heated with a reducing agent—to extract the pure metal.