China’s environment ministry on Tuesday said new aluminium production should no longer be encouraged in the country’s sprawling western region – in a proposal that goes against a current industry trend – and made the same suggestion for coke.

Aluminium smelters in China, the world’s top producer of the metal, are increasingly building plants in western parts of the country, particularly Yunnan province, to take advantage of cleaner hydropower, while China is cutting capacity for coke, a raw material in steelmaking.

Writing in response to a National Development and Reform Commission (NDRC) document released in August on “encouraged industries” for China’s West, the Ministry of Ecology and Environment said aluminium and coke should not be on the list.

The document had been circulated among government departments and the public for feedback on its proposals.

“Coking and electrolytic aluminium are high-polluting and high-energy consuming industries and they have overcapacity across the country,” the environment ministry said. “They should not be included in the catalogue of encouraged industries in the western region.”

China’s West，which occupies more than half the country’s total land area, includes the Xinjiang region – which had already become a hub for aluminium smelters due to lower costs and less stringent environmental requirements than in the east – as well as Tibet, Inner Mongolia and several provinces.

A line in the NDRC document encouraging aluminium smelters to move to Inner Mongolia provided they have replacement capacity quotas should be deleted, the environment ministry suggested.

It also recommended taking out a line calling for the construction of a more than 3 million tonne coking project in the same region.