Geology & Mining
Ferrowest has 100% ownership of the Western Australian mineral tenements shown here covering about 30,000Ha that are collectively known as Yogi. These mining and exploration leases form the basis of the Yalgoo Iron Project.
[ Click on the image to enlarge ]
The iron mineralisation at Yogi extends for approximately 30km trending roughly north-south. The visible outcrops of magnetite banded iron formations (“BIF’s”) start at the sourthern end of the tenement package and continue northwards to the northern most border.
Ground mapping, aeromagnetic surveys and more detailed ground magnetics surveys have been conducted over the entire BIF strike length at Yogi. Due to the outcropping and presence of magnetite, the BIF units can be targeted easily as they appear as magnetic “highs” as shown on the aeromagnetic map.
[ Click on the image to enlarge ]
This combined with geological interpretation and computer modeling has provided the Company with a very good understanding of the structure and extent of the BIF. Exploration drilling to date has confirmed the excellent correlation between the computer modeling and the actual ore body in the ground.
The iron in the Yogi deposit is in the form of magnetite which means that it needs beneficiation (upgrading) to increase the iron grade prior to processing into MPI. While the magnetite iron grades at Yogi are relatively low, this does not affect its suitability for MPI production. A high quality representative 67%Fe iron ore concentrate has already been produced from the Yogi magnetite. The additional costs of mining and processing the low grade magnetite from Yogi is offset by the advantages provided by the existing infrastructure (particularly natural gas, water and transport infrastructure). Critically, Yogi provides potential for a very long term (20+ years), stable supply of iron ore to the MPI plant and will allow expansion of MPI production in later years.
To date about 18km of the Yogi deposit have been drilled and an Inferred Resource of 552.2 million tonnes at 27.2%Fe has been classified and reported in accordance with the Joint Ore Reserve Committee (“JORC”) Code that governs the proper reporting of Resources and Reserves for companies listed on the Australian Stock Exchange.
The details of the Inferred Resources are:
|
Resource Classification(Ore Type) |
Million Tonnes |
Fe % |
SiO2 % |
Al2O3 % |
P % |
LOI % |
|
Inferred (Fresh) |
485.1 |
27.25 |
48.30 |
4.99 |
0.059 |
-0.15 |
|
Inferred (Transitional*) |
67.1 |
26.96 |
48.02 |
5.33 |
0.056 |
0.98 |
|
Inferred Total |
552.2 |
27.21 |
48.30 |
5.03 |
0.059 |
-0.02 |
112.5Mt of this Inferred Resource is located in granted Mining Leases and the balnce is located on the main Exploration Licence.
Mining of the orebody would be by simple open pit methods utilising a fleet of haul trucks, excavators and ancillary mining equipment such as blast hole drill rigs, bulldozers and graders. The project site is such that the beneficiation plant will be located a short hauling distance from the series of proposed mine pits.
The orebody has been drilled to a depth of between 130 and 200 metres depending on the width of the BIF beds which range from 30m to around 180m in the main pit areas.
It is likely that Ferrowest will contract the services of a recognised mining contractor to conduct mining operations at Yogi but self mining remains an option. Selective mining of the ore is planned to exclude any portions of the resource which would otherwise require excessive grinding. This will optimize the process efficiency and will require detailed grade control during mining but is expected to provide significant dividends in reduced equipment sizing and lower processing costs. Grade control of the mining operation will be managed in-house by Ferrowest as this is a critical function to ensure optimum beneficiation plant efficiency.
Mine planning will also take into account the option of increasing the production of MPI by adding further ITmk3(R) production modules to the MPI plant at Eradu (500,000 tonne per annum per module) in later years.
