US consulting firm Harbor General manager Jorge Vazquez recently challenged Goldman Sachs view, it expects 2018 aluminum supply will increase, therefore, aluminum prices may decline further in next year.

Harbor estimates that demand for aluminum production will reach 3.4 million tons in next year, which will be higher than 2.7 million tons this year. This year's average aluminum spot price will be at US$1,795/ton, next year will be reduced to US$1,670/ton.

This year the LME market aluminum average price is about US$1,879. Goldman Sachs earlier predicts that the shortage of aluminum in 2018, but it expects the surplus of aluminum in 2019.