ʻO Ferromanganese kahi ʻano ferroalloy i haku ʻia me ka hao a me ka manganese. ua hana ʻia ma ka hoʻomehana ʻana i ka hui ʻana o nā oxides MnO2 a me Fe2O3, me ke kalapona, maʻamau e like me ka lanahu a me ka coke, i loko o ka umu ahi a i ʻole ka ʻōnaehana ʻano umu ahi. kapa ʻia he umu ahi i hoʻopaʻa ʻia.