Studi pengaruh rasio massa pelet komposit bijih besi/batu bara terhadap hasil reduksi langsung pelet komposit bijih besi/batubara dengan menggunakan single conveyor belt hearth furnace = Study of iron ore/coal pellet composite mass ratio effect on direct reduction iron ore/coal pellet composite conveyor belt using single hearth furnace (Fakultas Teknik Universitas Indonesia, 2013)