Earlier Nui Beo, the largest open-cast coal mine in the northern province was completely closed in 2021 following the province's target to switch to more environmentally-friendly coal mining. Nui Beo started to shift to underground mining in 2012 and extracted its first tonnes in 2017. The mine achieved an output of 1.10 million tonnes last year.
Nui Beo used to be the biggest open cast coal source in Ha Long City with an average annual output of five million tonnes.
Quang Ninh plans to close the last open-cast coal mine operated by Ha Tu Coal Company latest by 2028 to transform entirely to underground coal mining.
The province has worked open-cast coal mines for decades, work that has had serious environmental consequences for Ha Long City and Ha Long Bay.