|
US2556542A
|
|
Defluorination of phosphate rock
|
|
US2556541A
|
|
Defluorination of phosphate rocks
|
|
US2562718A
|
|
Defluorination of phosphate rock
|
|
US2531068A
|
|
Defluorinating phosphatic material
|
|
US2499767A
|
|
Defluorination of phosphate rock
|
|
US2478200A
|
|
Defluorination of phosphate rock
|
|
US2531046A
|
|
Defluorination of phosphate rock
|
|
US2446978A
|
|
Defluorination of phosphate rock
|
|
US2231066A
|
|
Process for concentrating ores
|
|
US2047773A
|
|
Ore concentrating machine
|
|
US1880538A
|
|
Protection of phosphorus
|
|
US1902144A
|
|
Process for producing red phosphorus
|
|
US1879189A
|
|
Method of oxidizing phosphorus
|
|
US1888896A
|
|
Production of phosphorus and phosphoric acid
|
|
US1888919A
|
|
Treatment of phosphatic material
|
|
US1867239A
|
|
Reduction of phosphatic materials
|
|
US1192545A
|
|
Treating phosphates.
|
|
CA466326A
|
|
Defluorination of phosphate rock
|
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CA315031A
|
|
Thermic process for producing phosphorus
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