This time last year, the 65m tonne-a-year aluminium market was in turmoil after the US Treasury slapped sanctions on Rusal, the second-biggest producer outside of China, and its oligarch owner Oleg Deripaska.

Record Chinese exports in January and March have been a major factor in aluminium’s lacklustre performance this year, according to traders. But at a London conference late last week, Tian Yong, senior vice-president of Chinalco, China’s largest aluminium producer, said Beijing’s environmental reforms had been successful in curbing capacity and demand growth was on the rise.

There is now reckoned to be about 5m tonnes of capacity offline in China, with few signs it will be allowed to operate again. Meanwhile, as stimulus measures from Beijing help to spur economic growth, demand in China could outstrip supply this year, tipping the domestic market into deficit and creating global ramifications.

With demand improving and export arbitrages much less attractive than they were — the Shanghai aluminium price, for example, is moving higher while the London Metal Exchange price is becalmed — the chances of aluminium shipments picking up again, seem to be diminishing. (Analysts also reckon Chinese exporters tried to ship as much metal as possible before a key March deadline in the US-China trade talks that has now passed.)

As for inventories, the consultancy CRU believes the vast majority of stock built up after the global financial crisis will be gone by the end of 2019 or in 2020.

That could catch consumers by surprise and mean “backwardations” on the LME — a market structure where forward contracts are trading below spot prices, suggesting a real tightness of supply.

But if the risks for aluminium are on the upside the same cannot be said for alumina, the main ingredient needed to make aluminium.

The alumina price doubled in value to almost $700 a tonne last year on the back of Rusal sanctions and problems at a major refinery in Brazil.

As ever in commodities much will depend on China, which moved to fill the supply gap caused by the problems at Alunorte — which was accused of contaminating local drinking water — and also Rusal last year.

Just as they were the first to react to high prices by boosting production, Chinese refiners are likely to do the same on the downside, by cutting it. That should provide a floor for prices, in theory at least.