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Alumina

Alumina calcined

Alumina hydrated

Fused alumina

Summary

Alumina (aluminium oxide, or Al2O3) is a white powder produced from bauxite ores (iron alumino silicate).

Alumina containss 52.9 per cent aluminium in pure form.

Application

90 per cent of world production is raw material for the manufacture of aluminium with the balance used to produce aluminium chemicals.

Demand

Demand for alumina is projected to increase by 2 to 3 per cent. for YYYY.

Demand for aluminium is projected to increase by 2 per cent for 1998/99.

Demand for aluminium chemicals is TBA

Price

Price of alumina has averaged US 220 dollars per tonne in 1997, US 195 dollars per tonne in 1998, US 300 dollars per tonne in 1999.

Trade

Imports

...more coming soon...

Exports

The amount of alumina exported was 80% of production in 2000.

Production

The production of alumina was 15 million tonnes in 2000.

Production Capacity

Western Australia

Western Australia is the largest producing region in the world.

Producers:

- Alcoa World Alumina and Chemicals

- Worlsey Alumina

Alcoa World Alumina and Chemicals

- Pinjarra Refinery with production capacity of 4.2 million tonnes per year (last updated: Mar 2018).

- Wagerup Refinery production capacity of 2.4 million tonnes per year (last updated: Mar 2018).

- Kwinana Refinery with production capacity of 2.15 million tonnes per year (last updated: Mar 2018).

Worsley Alumina:

- Worsley Refinery with production capacity of 4.6 million tonnes per year (last updated: Mar 2018).

In 1999, production capacity was 10.4 million tonnes per year.

Alcoa has applied for a patent in July 1999 on a new process that improves the efficiency of alumina production by reducing the amount of carbonate in the Bayer Process circuit liquor. It is claimed to enable additional alumina production at a capital cost of 200 dollars per tonne compared with 590 dollars per tonne for expansion at Wagerup and 600 to 700 dollars per tonne to carry out the next phase at Wagerup.

Alcoa World Alumina and Chemicals operates the Kwinana refinery and is 40 per cent owned by Western Mining Corporation and 60 per cent by Alcoa Co of the USA trading as Alcoa Industrial-Chemicals-Asia.

In March 1999, Alcoa World Alumina reorganised its global bauxite and alumina business into two groups: Alcoa World Alumina Australia and Alcoa World Alumina Atlantic.

In September 1997, the Worsley Alumina smelter in WA announced it would spend 800 million dollars for expansion to 3.1 million tonnes per year for year 2000.

Northern Territory

Nabalco is building (1999) a 43 million dollars, 2700 tonnes/day fluid bed calciner at Gove, Northern Territory, the world’s largest; the unit will replace two of four rotary kilns, which will both be kept in working order in case of need. Site capacity remains at 1.75 million tonnes alumina, but costs, particularly energy costs, will be reduced. APA Group owns a 70 per cent interest. (APA comprises of Alcan of Canada, Pechiney of France and Ausuisse Lonze (Algroup) of Switzerland).

Queensland

Bauxite deposits are located on Cape York Peninsula. At Weipa Comalco (a Rio Tinto subsidiary) ships 9.5 million tonnes (capacity of 11 million tonnes) of beneficiated bauxite (and 200 000 tonnes of calcined bauxite). Alcan owns the Ely deposit but purchases 1.6 million tonnes of bauxite from Comalco with option for extension to 4 million tonnes.

About 7 million tonnes of bauxite is processed at the Queensland Alumina Limited refinery in Gladstone with a production capacity of 3.3 million tonnes of alumina (the largest in the world). Comalco owns 30.3 per cent and Alcan 23 per cent of the refinery.

Comalco is considering a 1 million tonne alumina operation for Gladstone, drawing on bauxite from Weipa deposits and using the alumina for its smelters at Boyne Island, Qld, Bell Bay Tasmania and at Tiwai Point, New Zealand. Expansion to 4 million tonne is envisaged. In April 2000, Comalco announced that in response to offered payments from the federal government, and the Queensland state government, it would not locate its proposed alumina refinery in Sarawak, Malaysia, but would evaluate the Gladstone site. At stage 1 it would cost A$1.4 billion, employ 450 and produce 1.4 million tonnes of alumina. By stage 3 it could produce 4 million tonnes per year. An alternative is the QAL site that could be expanded to 5.2 million tonnes which is managed by Comalco.

The federal and state governments have offered A$350 million (25 per cent of the cost of investment) to Rio Tinto (Comalco) to locate near the existing QAL plant. It is worth noting that the capital cost of a new alumina production unit is US$10 000 per tonne of alumina compared with expansion at US$5 000 per tonne. 

Production Costs

Electricity consumption for alumina is around 260kWh per tonne implying a cost of 8 per cent of market prices.

Australia's alumina refineries are among the lowest cost in the world. Alcoa's full operating costs has been estimated by some industry analysts at A$138 per tonne in TBA, down from A$152 in 1995. The following table shows estimates of full operating costs (year 2000), which are reducing at 3 per cent per year.

Worsley Refinery: US$88.94

Wagerup Refinery: US$93.04

Damanjodi Refinery: US$102.70

Pinjarra Refinery: US$103.51

Gove Refinery: US$112.34

Belgaum Refinery: US$116.38

Gladstone Refinery: US$119.01

Bauxilum Refinery: US$127.66

Pinnguo Refinery: US$133.81

Kwinana Refinery: US$136.17

Poco de Calcos Refinery: US$139.19

Technology

Alumina is produced by treating bauxite ore with caustic soda in the Bayer process. This process involves digesting bauxite at high temperatures with caustic soda which dissolves the alumina as sodium aluminate leaving iron oxide and silicates as waste products (red mud). On controlled cooling, alumina hydrate is precipitated which is calcined (heated) at 900 to 1000°C to alumina. Caustic soda is lost mainly with the clay and iron oxide particles. About one tonne of caustic is consumed for every 13 tonnes of alumina produced requiring about 25 to 27 gigajoules of gas per tonne of alumina (depending on the nature of the bauxite)..

Raw Materials

Bauxite ore

...more coming soon...

Caustic soda

link

Calcined alumina

Alcoa produces about 50 000 tonnes of calcined (tabular) alumina, principally for the export market with applications in refractory cements.

Alumina can also be used to prepare special calcines that may include low soda (0.2% Na2O) and high surface area (50m2/gm) for specialist applications such as insulators for batteries. At present this strategy has not been pursued in Western Austra

Hydrated alumina

During 1995, the KB-30 project was commissioned at Alcoa of Australia's alumina plant at Kwinana to reduce the organic contaminants. Owned by ACAP Singapore and ACAP Australia part of the worldwide Alcoa group, the plant has the capacity to produce 270 000 tonnes per year of alumina hydrate valued at around 45 million dollars.

The Kwinana refinery, having commenced in 1963, operates five small units providing flexibility. Part of the alumina stream may be further processed with various filtration and impurity removal steps to produce a clear hydrate.

It is relevant to note that Alcoa uses some of the lowest grades of bauxite in the world which normally produces a high level of organic by-product. The small fragmented scale of operation of this old Kwinana plant enables it to overcome this handicap.

There are several grades. KB-30 is 99.5+% Al2O3.3H20 with 0.25% Na2O which is exported for use in the production of aluminium chemicals such as alum, sodium aluminate, poly-aluminium chloride and detergent zeolites, including for use in paper, fire retardants and water purifiers. It is also used in titanium dioxide pigment manufacture to improve its properties.

Other grades of lower purities and colouration are produced and sold to Companies such as Coogee Chemicals at Kwinana.

Fused alumina

Fused alumina is a granular material with a melting point of around 2 500°C and a hardness of 9 on the Mohs scale. It is used in a range of refractory bricks and monoliths and as abbrasive.

Australian Fused Materials, today owned by Japan Abrasive Company, ACAP (Alcoa of Australia) and Doral Minerals (owned by Iwatani International Corporation) was established in 1991 and now has a production capacity of 20 000 tonnes of fused alumina (corundum) per year. The plant is located at Rockingham, near Kwinana and the Alcoa refinery, some 40 km south of Perth.

The fused alumina is produced by fusing a low soda calcined alumina produced by the nearby Alcoa refinery in an electric arc furnace. The fused product is poured into ingots, crushed, sized and bagged.

It is a very energy intensive process requiring 2 000 kWh of electricity per tonne of product (at industry standard of 0.06 dollars per kWh, is 12 per cent of market value).

About 80 per cent of production is exported and in 1992-93 AFM exported about 8 400 tonnes valued at 7.2 million dollars for use as abrasives and as refractory. Capacity has since been doubled to 20 000 tonnes.

The company also produces fused zirconia.

Australian Fused Materials, PO Box 84 Rockingham, WA 6168, Tel +618 9439 2236, Fax +618 9439 2892