SA energy crisis affects Mozambique aluminium export

Mozambique’s production and exports of aluminium will be lower than hoped for this year, owing to electricity shortages in South Africa. Resources giant BHP Billiton’s Mozal aluminium smelter MD Raitt Marshall confirmed earlier this year that 2008 would see a reduction in exports, but he did not put a figure on this. Marshall said that, in late Jan-uary this year, Mozal received instructions to reduce its electricity consumption by 10%. The normal consumption at the smelter is about 950 MW, making Mozal the largest consumer of electricity in Mozambique. The power for Mozal comes from joint-venture company Motraco, formed by the South African, Mozambican and Swazi electricity companies, Eskom, Electricidade de Mo?ambique and the Swaziland Electricity Board respectively, but Motraco draws its power from Eskom. Owing to chronic underinvestment in the new plant, Eskom is no longer able to meet the demand from all its clients, and so rolling power cuts hit South Africa early this year. Eskom told its main industrial customers to cut their use of power, and the aluminium smelters in which BHP Billiton is the major shareholder were no exception. Marshall said that all three of the smelters, Bayside and Hillside in the South African port of Richards Bay, and Mozal in Maputo, had to take several furnaces, or pots, where alumina is reduced to aluminium by electrolysis, out of commission. To achieve the required 10% cut in January, Mozal was obliged to switch off 47 of its 500 pots. Subsequent negotiations with Eskom led to a concentration of pot closures in the oldest smelter, Bayside, so that more power could be spared for the more modern smelters at Hillside and Mozal. Mozal is braced for further disruption. Marshall said the company has been told by Eskom that it will be five years before the power supplies are normalised. Mozal officials told the public that the company continues to meet high environmental and safety standards. The main pollutant emitted by aluminium smelters is fluoride. The World Bank sets the highest acceptable figure for fluoride emissions into the atmosphere at 1 kg of fluoride for each ton of alumi-nium produced. Figures provided by health, safety and environmental specialist Ana Lobo show that in most months Mozal emits less than 0,5 kg of fluoride for each ton of aluminium. In 2001, the figure was 0,68 kg, falling to 0,61 kg in 2002, 0,46 kg in 2003, and 0,39 kg in 2004. This year, the figures have risen somewhat, which Lobo attributes to the lower production of aluminium, but are still well within safety levels. Thus, in March and April, the smelter emitted 0,45 kg of fluoride for each ton of aluminium, a figure which climbed to 0,52 kg in May. A retention lake prevents fluoride from being washed into the nearby Matola river. The water is only released from the lake after tests show that the fluoride content is within safety levels. Mozal specialists also regularly monitor the quality of the water in the river itself. Lobo stressed that Mozal knew of no impact on human health of its activities. Mozal claims that it provides an extremely safe working environment, with very few of its workers suffering classified injuries, which prevent these workers from working for at least a day. The classified injury frequency rate at Mozal fell from 3,1 to 1,03 for every million working hours, between 2004 and 2007. The latest figure, for the 12 months prior to May 2008, is 1,1 classified injuries for every million working hours. --engineering news