Aluminium processors continue to invest

Paul Boughton
Investment continues in major new aluminium production plants, while a new process could reduce the industry's huge energy bills. Sean Ottewell reports.

The Ma'aden-Alcoa joint venture has selected Wagstaff to supply the joint venture's vertical direct chill casting complex with t-ingot, rolling ingot, and extrusion billet casting equipment. The contract includes capital equipment and technology to produce aluminium rolling ingot and extrusion billet at the casting complex, currently under construction and scheduled to start production in 2013 in Ras Az Zawr, Saudi Arabia.

The greenfield smelter and rolling mill comprise the first of two phases in this super-project, which will leverage Saudi Arabia's bauxite and energy resources with Alcoa know-how, management expertise and support to create what the jv describes as the world's largest and lowest cost fully integrated aluminium manufacturing complex (Fig. 1).

The rolling mill will be the region's first and one of the most technologically advanced in the world and will primarily produce can stock, end stock and tab stock for the regional market. It will have initial hot-mill capacity of between 250,000 and 460,000 metric tons per year.

The new contract for the casting complex supply includes Wagstaff leading edge ingot and billet casting systems, as well as integrated automated controls, which have been shown to deliver improved recovery rates, and higher levels of workplace convenience and safety. The casting facility will also feature Alcoa's advanced proprietary ingot casting technology which yields highly improved surface finish to rolling ingots with consequential gains in rolling efficiency and product quality.

"As a longstanding, dedicated supplier to global Alcoa casting facilities and with many successful greenfield installations in the Middle East and around the world, Wagstaff is uniquely positioned to provide precision, state-of-the-art direct chill casting equipment to the Ma'aden Alcoa joint venture, and to remain a constant resource from current equipment design activities through delivery, commissioning, operator training, post-startup technical support, and beyond," said Ray Kilmer, vice president, Alcoa Global Rolled Products.

Meanwhile, primary aluminium production at the Qatalum plant in Qatar is expected to recommence shortly. The plant had been shut down since 9th August when a power outage caused the cells to cool down and the liquid metal to solidify.

The clean-out of the 444 cells that were affected by the power outage, which lasted nearly five hours, is well underway. The Qatalum organisation has since, with the strong support of both owners, focused on preparing the cells for a safe and secure restart, investigating the causes and effects of the incident and implementing mitigating actions.

According to external and internal experts investigating the incident, the long-lasting outage was due to unexpected technical difficulties in restarting the power plant after it was closed down by an external earth fault, which also disrupted Qatalum's connection to the national grid in Qatar.

Despite strong efforts to restore power supply, the duration of the outage caused the cells to cool down and the liquids to solidify. The primary aluminium production was subsequently shut down. The root causes of the incident have been identified and are being rectified.

"I am pleased that Qatalum now is in the position to resume production shortly. It is of course most unfortunate that such a setback should hit us now, as we were in good progress of ramping up the plant towards full production. At the same time we are glad that the events did not lead to any injuries," says Abdulla Salatt, chairman of the board of directors.

"Our prime objective is to prevent similar incidents in the future, and I am confident that we have technical solutions and routines in order to achieve this. The Qatalum organisation has put in a tremendous effort in mitigating the consequences of this unfortunate incident. Internal and external resources have been mobilised to ensure a safe and quick restart. Regional smelters provided support and shared expertise, equipment and materials," says Qatalum's ceo Jan Arve Haugan.

Qatalum's insurance coverage related to the incident is considered robust: "We have insurance related to property damage and loss due to business interruption and we are in a constructive dialogue with our insurers to determine the financial impacts of this incident," Haugan says.

Qatalum is a 50-50 joint venture between Qatar Petroleum and Norsk Hydro. When complete, it will be one of the most modern, energy-efficient and environmentally high-performing aluminium plant in the world, with an annual production capacity of 585,000 tonnes of aluminium. The plant has a total of 704 cells (Fig. 2).

In Australia, Melbourne-based company Calsmelt has completed a 'concept proof' stage of technology development for its Thermical process. Calsmelt holds an exclusive worldwide license to the novel carbothermic smelting technology for aluminium production developed by the Australian company Thermical.

Calsmelt co-founder and interim ceo Dr Greg Smith described Thermical technology as a significant breakthrough for the production of aluminium at a significantly lower cost, and in a much more environmentally friendly manner: "Calsmelt is delighted that its work on the Thermical technology has now been proven to the point that within a couple of years we will be ready to build a first small, but commercially viable plant."

Calsmelt's chief scientist, co-founder and technology inventor Dr Yaghoub Sayad-Yaghoubi commented: "For around 70 years now, the aluminium industry has been searching for a suitable carbothermic technology to smelt aluminium in a similar manner to the way steel is produced. Such a technology would help it overcome the well-known limitations of the industry's current, pervasive electrochemical approach. While some promising approaches were considered over the last two decades, these were found to have significant shortcomings that prevented their commercial introduction. Our Thermical technology overcomes all of these limitations and finally creates real potential for the industry move to carbothermic smelting for aluminium - at a time when the industry is under economic and environment pressure."

He added: "We believe that Thermical technology will insure a competitive future for the aluminium industry by drastically reducing the costs and environmental footprint of metal production. Capital costs will be reduced by 77-80 per cent, while the operational cost will be lowered by about 40 per cent. Power consumption will be about 40 per cent lower. The currently troubling fluoride emissions found in the electrochemical process will be completely eliminated and the quantity of generated gases will be significantly lower. Thus, the global warming potential of the Thermical process will be 40-60 per cent lower than in the current electrochemical process."

The first stage of the Thermical process requires significantly lower temperature and does not produce any gas. Unlike the conventional process, therefore, it does not require a separate fume collection and treatment system at this stage. The second stage of the process operates at a lower temperature than conventional carbothermic processes, too, reducing cost of gas collection and treatment, while ensuring a lower carbon content in the produced metal.

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