BEIJING, Aug 23 (Reuters) – China’s July aluminium imports leapt nearly sevenfold year-on-year to their second-highest level on record, customs data showed, as a rare price phenomenon saw the world’s top exporter of the metal turn net importer for the first time since 2009.

Arrivals of unwrought aluminium and aluminium products into China aCNIMPALUM came to 391,297 tonnes last month, the General Administration of Customs said on Sunday.ADVERTISINGAds by Teads

That is the highest monthly total since April 2009, when China imported almost 440,000 tonnes. It was up 570% from July 2019 and up 35.5% from 288,783 tonnes in June this year.

The import volume beat China’s July export total of 373,402.3 tonnes, with the coronavirus pandemic hitting overseas demand.

That means China, the world’s biggest producer of aluminium, was a net importer of unwrought aluminium and aluminium products last month for the first time since September 2009.

Imports in the January-July period rose by 284.4% year-on-year to 1.21 million tonnes, according to additional data released on Monday. China imported around 2.32 million tonnes in the whole of 2009.

The recent bumper shipments came amid a wide disparity between aluminium prices in China SAFcv1, where demand has recovered since the coronavirus outbreak earlier this year, and lower international prices on the London Metal Exchange CMAL3.

The spread between the two prices LMESHFALc0, known as an arbitrage, meant Chinese consumers – who usually have little need for foreign aluminium – were able to source primary metal more cheaply from overseas. Imports of secondary, or remelted metal have also been increasing.

With London aluminium prices rising by 5.8% in July, this arbitrage window has now shut, but large volumes were still coming into China because contracts to ship the metal were signed earlier when the arb window was open, said CRU analyst Wan Ling.

Customs is due to release a breakdown of imports by origin and type of aluminium and other commodities on Tuesday.