China's exports of aluminium have likely peaked in the wake of a series of trade protection moves in key markets around the world but the country is now shipping higher value-added products overseas, consultancy CRU said on Wednesday.

China, the world's top producer of aluminium, saw exports of unwrought aluminium and products fall for a second straight year in 2020 to 4.86 million tonnes, as a coronavirus-driven knock to demand for Chinese metal exacerbated the impact of a flurry of anti-dumping tariffs imposed since 2017.

"Now we're in a situation where Europe and the US have pretty comprehensive anti-dumping measures against Chinese imports and China is going out to the rest of the world and seeing if it can replace those markets," said Eoin Dinsmore, CRU's head of primary aluminium and products.

"And as a result, you get lots of new anti-dumping cases coming in smaller countries," he told the CRU World Aluminium Conference.

"We think we are not going to get back to the levels, the highs we saw in 2018 on a monthly basis," Dinsmore said, referring to a time when China was consistently exporting more than half a million tonnes each month.

However, faced with anti-dumping cases on semi-finished products such as foil and sheet, China is now exporting more finished aluminium products with higher value added, he said.

Meanwhile, CRU has downgraded its 2021 production forecasts for two of China's aluminium smelting hubs, Yunnan and Inner Mongolia, by a combined 1 million tonnes as they come under pressure to reduce energy consumption.

China's aluminium output fell in May from April's record high due to curbs on smelters' electricity use.

"This is not a one-off event," Dinsmore said. If other smelting hubs such as Xinjiang or Guangxi start lagging behind targets, cracking down on energy-intensive aluminium production would be "an ideal way to very quickly reduce your energy consumption," he added.