Pengaruh penambahan 10,13,15,dan 20% reduktor antrasit dan arang batok kelapa terhadap reaksi karbotermik bijih nikel saprolit = Effect of 10, 13, 15, and 20% antrachite, and coconutcharcoal reductor addition on carbothermic reaction of saprolitic nickel ore ([Fakultas Teknik Universitas Indonesia, ], 2009)