알루미늄과 산소의 화합물로, 자연계에서 보크사이트나 강옥의 형태로 산출되는 흰색 고체.
A white solid compound of aluminum and oxygen, occurring naturally as corundum and bauxite, used in the production of aluminum metal and ceramics.
예문:
"Alumina is the primary raw material used in the smelting of aluminum metal."
"The ceramic industry uses alumina for its high melting point and durability."
"Corundum is a crystalline form of alumina that ranks nine on the Mohs scale."