Assertion: urine's phosphorus | /r/AtLocation | metallic copper
Facets:
value: to react with oxygen present
type: PURPOSE
value: during its smelting process
type: TEMPORAL
Source sentences:
text: Phosphorus is added to metallic copper during its smelting process to react with oxygen present as an impurity in copper and to produce phosphorus-containing copper (CuOFP) alloys with a higher hydrogen embrittlement resistance than normal copper.