About: http://webisa.webdatacommons.org/66557261

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Impurities, in particular alkali metals, can be particularly effectively removed by sublimation of the roasted materials.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com