Influenced by the unexpected devaluation of the RMB, China's expanding aluminium exports will be further boosted. China is a global aluminium producer.

Goldman Sachs said that despite the fall in aluminium prices, many producers had not cut output, partly because of government subsidies. Meanwhile, China's weak domestic demand has stimulated a large number of aluminium exports to the global market. From January to July this year, China's aluminium exports increased by 28% year-on-year, a record high. With this week's devaluation, the aluminium market will welcome more supplies, as the weakening of the people will reduce domestic production costs.

Stephen Briggs, an analyst at BNP Paribas, said in the report: "Clearly negative, which reduces domestic production costs in dollar terms." This year, LME's three-month aluminium slumped 14% to $1,589 a tonne. According to Harbor Intelligence, the average cost of producing raw aluminium per ton in China has been reduced by $12 to $1,728 after a 1.9% devaluation. The company expects that people will depreciate 10% against the dollar and further cut costs by $50 to $1,678 per ton.

According to customs data, by July this year, China had exported 2.87 million tons of unwrought aluminium and aluminium products, a record high. "The devaluation of the RMB has restored China's export competitiveness," Jorge Vazquez, general manager of Harbor, said in a report Tuesday. "China's structural economic growth is slowing down, and overcapacity and overproduction will be the main drivers of falling commodity prices."