sentence: Pure aluminium is made from bauxite, a kind of rock that has aluminium oxide and many impurities.
sentences_after: The bauxite is crushed and reacted with sodium hydroxide. The aluminium oxide dissolves. Then the aluminum oxide is dissolved in liquid cryolite, a rare mineral. Cryolite is normally produced artificially though. The aluminium oxide is electrolyzed to make aluminium and oxygen.
concept_name: pure aluminium
headings: Aluminium Occurrence and preparation
categories: Metals