Xstrata said its $246m expansion plan for the George Fisher mine in Mount Isa has been approved by the Queensland Government.

The expansion will increase the annual production rate by almost 30% from 3.5 million tons to 4.5 million tons from 2013.

Xstrata chief operating officer Brian Hearne said that the mine contains one of the largest zinc reserves in the world, and that the expansion project would allow the company to further tap its significant resource potential.

The increased production rate will reduce the life of Fisher mine by five years to 21 years, but the ore body will remain open at depth to the north of the mine, Hearbe added.

Xstrata has increased zinc reserves at the operation by 126% to 76 million tons from 33 million tons when the mine was acquired in 2003.