Causticization process for refining alumina.

Alcoa World Alumina says it has developed an efficient causticization process for use in refining alumina.

A research team at Alcoa's Kwinana works in Western Australia developed the process, which is said to improve productivity at a refinery by reducing the amount of carbonate in the Bayer circuit liquor. Other benefits claimed are improved lime efficiency and a decrease of alkalinity in mud residue.

The company estimates that applying this process to its refineries worldwide will increase production by 500 000 tonnes a year. Full commercial trials are being planned at the company's refineries in Kwinana and Point Comfort, Texas, USA. Alcoa has already started engineering a retrofit at its Pinjarra refinery in Western Australia, which will result in an expansion of the capacity by 165 000 tonnes a year by early 2001.

All other Alcoa refineries are expected to be ready by late 2001.

Alcoa World Alumina, based in Pittsburgh, Pennsylvania, is the commercial centre of Alcoa's global bauxite and alumina activities.

For further information, contact: Alcoa, 201 Isabella Street at the 7th Street Bridge, Pittsburgh, PA 15212-5858, USA; tel: +1-412-553-4545; Internet: http://www.alcoa.com