Quicklime is used to remove acidic acids from a power station chimney and as a way of cleaning silica from a blast furnace. It is also used as a main ingredient in cement and in paper mills.
Scientists believe quicklime, or calcium oxide, may have been used in ancient Greece as a fire source. Since quicklime can ignite fuel when coming in contact with water, it may have been used to start cooking fires. It was once used in stage lighting because when heated to over 2,400 degrees Fahrenheit, calcium oxide emits a bright glow, called a limelight.
Quicklime is also used in the petroleum industry as an alkali in biodiesel production.