cupola for smelting manganese ore

US3433628A US3433628DA US3433628A US 3433628 A US3433628 A US 3433628A US 3433628D A US3433628D A US 3433628DA US 3433628 A US3433628 A US 3433628A Authority US United States Prior art keywords furnace manganese ferromanganese weight process Prior art date 19650915 Legal status The legal status is an assumption and is not a legal conclusion