Bens Creek Group PLC (AIM:BEN, OTC:BENCF) said it has started underground mining to produce High Vol A (HVA) coal.
Adam Wilson, chief executive, said: "This product enhances our offering to Integrity Coal, our offtake partner.
“The addition of HVA to our product line will further add value to our business."
HVA is one of the four grades of coking coal that are largely used to make steel.
Bens Creek already supplies an HVB coal product equivalent to Integrity from its existing operations, but HVA is higher quality and will receive a premium price.
The price of HVA coal on 24 May 2022 was US$468 per metric tonne, US-based Bens Creek added in a statement.