Higher revenues, low inventories, continuation of orders from the automobile sector and improved prospects for sales in the new US market have put Dubai Aluminium (Dubal) in a buoyant mood despite uncertain conditions in some of its markets.

The company, the world's largest manufacturer of foundry alloy used mainly by the automobile industry as well as being a producer of extrusion billet and high-purity aluminium, is running at a full capacity of 536,000 tonnes per annum of high-quality aluminium sought by companies from all over the world. The capacity was raised from 372,000 tonnes following an expansion in March last year, which saw a sixth potline being added. The company also made strides in the US in 2000, thereby diversifying its export base to cover the world's important industrial markets.

Senior Dubal officials have confirmed that revenues for 2000 were up 25 to 30 per cent. Chief executive John Boardman said the company was still seeing very strong demand, observing that the order books did not mirror the uncertain conditions in some of the company's export markets. Production was at full capacity and in fact sales had been quite strong in the last three to four years with one of the lowest inventories.

Boardman also observed that Dubal was now in the process of consolidation after the commissioning of projects that raised capacity last year and earlier in 1997. He said the company was also endeavouring to lower costs. The consolidation process would take time and the company was ready to meet any developments in the industry.

"Dubal's core market is the Far East including the most exacting customers in Japan, Korea, Taiwan and Thailand who account for over two thirds of total sales. A growing proportion of production is serving Middle East customers while a number of technically advanced European companies prefer Dubal products over nearer sources despite the 6 per cent EU duty," said a Dubal spokesman.

Boardman said there were "soft patches" in the US and Europe between September and December but that he believed the industry had come through the worst with demand patterns very much in place for the next three months at least. Company officials believe there could be an improvement in the US market in the second half of this year resulting in better demand.

The company says there have not been cancellations of orders from the automobile industry, which is a big customer for foundry alloy used in the production of automotive wheels. Foundry alloy accounts for some 40 per cent of Dubal's total production. While most of the alloy goes to the Asian market, a selection of wheel alloys has been specifically developed to suit European technology.

Accounting for most production is extrusion billet (50 per cent), destined mainly for the construction industry.

"The superior quality of this product is derived from the purity of the metal, 'airslip' hot top casting and a state-of-the-art continuous homogenisation process," said a Dubal spokesman. The billet is available in a range of alloys and diameters from 152mm to 355mm and can be supplied in lengths of up to seven metres.

Some 10 per cent of Dubal's production constitutes high-purity aluminium of 99.95 to 99.97 purity cast in 20kg or 500kg ingots. The product is used by the electronics and computer industries.

Production at Dubal takes place in a smelter consisting of 984 reduction cells or 'pots' housed in six potlines. While there has been considerable development into optimising conditions in the pots, the basic electrolytic theory of aluminium smelting has gone unchanged since its discovery by chemists Hall and Heroult in 1886.

The pot's inner lining of pre-baked carbon is embedded with steel electrical current collector bars forming the cathode or negative electrode. Pre-baked carbon anode blocks are suspended by metal rods in a molten mineral called cryolite and carry the anode current into this electrolyte liquid.

Powder of alumina or aluminium oxide, the basic raw material for aluminium manufacturing, is fed automatically into the pot through overhead hoppers where it dissolves easily in the molten cryolite at a temperature of about 965 degrees C. The alumina in solution in the cryolite breaks down as a result of electrolysis to produce oxygen and metallic aluminium. The molten aluminium sinks to form a pool on the cathode at the bottom of the pot and is vacuum trapped from the pot into a six-tonne crucible approximately every 32 hours. The molten metal is transferred to the Casthouse where it is further treated and cast into finished products. Each pot yields between 1.3 to 1.5 tonnes of metal per day.

The oxygen liberated during electrolysis reacts with the carbon anode blocks, gradually consuming them to form carbon dioxide. Anodes last for around 24 days in the pot and each is changed sequentially when reduced to a quarter of their original size. The butts are then cleaned, crushed and recycled to make new anodes.

The production capability of Dubal's pot has been considerably enhanced over the years through continuous research and development, placing it among the best operating pots in the aluminium industry today.

"Lines 1-4 were originally designed to operate at 150kA with a current efficiency of 87.5 per cent. Through a redesign of the thermal characteristics, improvements in electrolyte composition and increasing the anode effective area, the pot now operates at 180kA and has a current efficiency of 94.4 per cent, providing substantially increased production capacity," said the Dubal spokesman.

"The advanced technology jointly developed by Dubal and Comalco of Australia, used in lines 5 and 6, operates at 200kA with a current efficiency of 94.5 per cent."

The company imports raw materials including around 1 million tonnes of high-quality alumina from Australia, more than 180,000 tonnes of calcined petroleum coke from the US and around 45,000 tonnes of coal tar pitch from Europe and the Far East. These arrive by sea directly at Dubal's own dock at the Jebel Ali terminal where alumina and petroleum coke shipments are stored in silos at the dock facility, while coal tar pitch is taken directly to the plant.

Also imported are aluminium fluoride, cryolite, calcium fluoride, cast iron, ferro-alloys, silicon, magnesium, titanium and iron, all of which are required for aluminium smelting and casting.

The company also manufactures about 300,000 anodes, each weighing more than one tonne, at Dubal's own carbon pant.

For aluminium smelting, nine times more energy is required than for producing steel. Once made, the energy required to re-melt or recover scrap is only five to seven per cent of the energy required to extract it from its ore.

Electrical power required for the electrolysis of alumina is provided by Dubal's own power station consisting of 18 industrial gas turbine generators: eight GE Frame 5 units each producing 20MW, five GE Frame 9B units producing 75MW each, one ABB 13 D2 (GT14-arranged as a combined cycle turbine) producing 82MW, four Frame 9E gas turbines producing 110 MW each and two 125 MW steam turbines.

The gas turbines have associated heat recovery boilers that enable the power station to have a total rated power generation capacity of around 1,450 MW. The main fuel for the power station is gas associated with oil production.

Exhaust heat from the gas turbines is converted to provide up to 700 tonnes of steam per hour. The steam is fed at an inlet pressure of about 17.5 atmospheres to two backpressure steam turbines, which together provide 72MW of fuel-free electrical power. The steam then exits and is available to provide the process heat needed to desalinate seawater. Dubal has the capacity to produce up to 30 million gallons of water daily.

Sophisticated pollution monitoring equipment has been installed in the smelter as an integral part of the complex and now includes two electrostatic precipitators with an evaporative cooler and six fume treatment plants.

"A stringent pollution monitoring programme is in operation with eight ambient air sampling stations within the complex and in neighbouring Jebel Ali v8 million bpd, but the average production target for the 2000 to 2005 period remained unchanged despite the accident, Petrobras said.

Oil analyst Frank McGann of Merrill Lynch in New York said the reviewed targets came in slightly above his current estimates.

Petrobras' P-36 deepwater rig, which used to produce 80,000 bpd of crude, sank in March after a series of explosions killed 11 crew members. uality Award for Manufacturing in 1996 after an in-depth study of the company's operations and processes by an independent panel of judges. In 2000 it received the Dubai Quality Award, Gold Category.

Since its beginning in 1977 when construction work on the smelter began under the guidance of the late Shaikh Rashid bin Saeed Al Maktoum, followed by the first tapping of the metal in 1979, the company has made tremendous strides and is now reckoned as contributing 45 per cent of Dubai's non-oil revenue.