Assertion: tungsten | /r/HasProperty | prepared
Facets:
value: by heating the powdered ore
type: MANNER
value: from wolfram
type: OTHER
Source sentences:
text: Tungsten may be prepared from wolfram by heating the powdered ore with sodium carbonate, extracting the sodium carbonate with water, filtering and adding an acid to precipitate tungstic acid, H 2 W0 4.