alumina

noun alu·mi·na \ ə-ˈlü-mə-nə \

|Updated on: 10 Jul 2018

Definition of alumina

: the oxide of aluminum Al₂O₃ occurring native as corundum and in hydrated forms (as in bauxite)

Recent Examples of alumina from the Web

Raw materials including coke, which helps to fuel iron-ore smelters, and caustic soda, used to extract alumina from bauxite, are also rocketing higher in price.

— rhiannon hoyle, WSJ, "What Goes Around Comes Around: Energy Prices Dig Into Miners’ Profits," 12 Mar. 2018
Below that sits an alumina-zircon-silica nozzle, which can programmed to make the same intricate moves in X-, Y-, and Z-space familiar to anyone who has seen a 3D printer in action.

— jake swearingen, Popular Mechanics, "MIT Creates a 3D Printer for Glass," 21 Aug. 2015
Bloomberg News reported that Rusal officials met Chinese companies and traders this week to discuss the possibility of buying alumina and selling aluminum in the Asian country.

— david hodari, WSJ, "Wanted: New Home for a Lot of Russian Aluminum," 20 Apr. 2018
Rusal had provided 7 percent of the world’s alumina, the raw material for aluminum production.

— eric levitz, Daily Intelligencer, "Trump Administration Eases Sanctions on Russian Metal Giant," 23 Apr. 2018
The disruption -- playing out as U.S. sanctions on Russian aluminum giant United Co. Rusal ripples through the metal’s supply chain -- has helped send an alumina index to a five-month high.

— Bloomberg.com, "Brazil Ponders Fate of Key Aluminum Ingredient Maker," 13 Apr. 2018
Such proposals often involve sulfates, particles that form in the stratosphere from sulfur dioxide ejected by volcanoes, or other molecules with high reflectivity, such as diamond dust or alumina (aluminum oxide).

— paul voosen, Science | AAAS, "A dusting of salt could cool the planet," 21 Mar. 2018
The practice is common in aluminum production, where the smelting process uses vast amounts of electricity to create aluminum metal from alumina.

— megan geuss, Ars Technica, "New York power companies can now charge Bitcoin miners more," 16 Mar. 2018
Bauxite is a clay rock that is refined to produce aluminum hydroxide, or alumina, which is then smelted to produce primary aluminum (secondary aluminum comes from recycled scrap).

— greg ip, WSJ, "The Flaw in Trump’s National Security Tariffs Logic," 9 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'alumina.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of alumina

New Latin, from Latin alumin-, alumen alum

NEW! Time Traveler

First Known Use: circa 1790

in the meaning defined above

See Words from the same year

Medical Dictionary

alumina

noun alu·mi·na \ ə-ˈlü-mə-nə \

medical Definition of alumina

: an oxide of aluminum Al₂O₃ that occurs native as corundum and in hydrated forms (as in bauxite) and is used in antacids — called also aluminum oxide