Fortescue Metals Group has again increased its iron ore resource at Nyidinghu, after uncovering an additional 450 million tonnes.
In October 2011 the miner increased its total delineated resource at the site from 1.03 billion to 2.01 billion, with a cut off grade of 52% Fe.
At the time Fortescue said "it is contained within an area of about 14 square kilometres, and has an expected strip ratio of less than 2:1".
Now it has once again increased the resources at the site, pushing the total amount to 2.46 billion tonnes, using the same 52% grade cut off point.
This estimate includes a measured resource of 23 million tonnes at 59.6% Fe and indicated resources of 580 million tonnes at an average grade of 58.1% Fe.
The remaining 1.86 billion tonnes is still classified as inferred.
The Nyidinghu operation is only 35 kilometres south of Fortescue's existing Cloudbreak operation, within its Chichester Hub.
FMG stated that it is confident that this Nyidinghu resource will eventually exceed three billion tonnes once all definition drilling has been carried out.
It has also carried out an estimated using a cut off grade of 59% Fe, which gives a total of 735 million tonnes at an average grade of 60.6%.
At this grade around 15 million tonnes is classed as measured (at 61.1% Fe), 237 million tonnes as indicated (at 60.7% Fe), and 483 million tonnes (at 60.6% Fe) is classified as inferred.
On top of this the higher grade resource is essentially all bedded iron mineralisation hosted within the wider Brockman Iron Formation "which is the most prolific source of high grade bedded iron ore in the Pilbara region," Fortescue stated.