The project comprises a 145 hectare mining lease that covers a two kilometre long, 300 metre wide zone, prospective for structurally controlled iron ore formation (locally called itabirite) that adjoins the Vale owned Piçarrão mine (also mined in the 1980s). It is located in the north eastern part of the world famous Iron Quadrangle (Quadrilátero Ferrífero) within the iron rich Itabira belt.
Centaurus has the right to purchase up to 60% of the Liberdade Project from Mineracao Marsil Ltda who have owned the project since the 1980s when it was last in operation. The Liberdade mine last operated in the 1980’s when it formed part of the production for CVRD (now VALE). The mine ceased operation due to historically low iron ore prices. Historical production records indicate that the ore mined was consistent with the highest quality of the district. High grade iron ores of up to 65% iron (Fe) were recorded with low contaminants such as phosphorous (P), aluminium, (Al2O3) and silica (SiO2). No drilling and blasting was required when the mine was in production.
Centaurus has defined an initial resource at Liberdade and is now discussing with its joint Venture partner the best way to realise value from the rights and interests that it currently currently holds in the joint venture. No work is currently being undertaken at the project.
INITIAL RESOURCE CALCULATION
At the Liberdade Project a JORC compliant Inferred and Indicated resource of 5.31 million tonnes at an average grade of 43.3% iron with low contaminants has been estimated by international mining consultants Coffey Mining Pty Ltd (Coffey Mining) .
The deposit is characterized by discrete layers of iron rich horizons in a tabular form. These iron rich horizons are distributed throughout the project area over approximately 2.5km striking in a northeasterly direction. The iron mineralization varies from friable itabirite and hematite to compact itabirite and hematite.
Massive boulders of compact hematite or Lump Ore can be found scattered throughout the old open pit mine. These boulders have not been included in the Resource calculation.
SIMPLE, LOW COST BENEFICIATION
Preliminary beneficiation testwork has confirmed that the itabirite mineralisation can be easily upgraded to a high grade iron product. Initial metallurgical testwork undertaken through the onsite gravity separation pilot plant, independently assayed by ALS Chemex and by VALE demonstrates very good upgrade characteristics with even the lower grade ore upgrading to a high grade hematite sinter product that is low in contaminants.
Beneficiation Upgrade Testwork of Liberdade Ore carried out by VALE.
| |
Fe% |
SiO2% |
Al2O3% |
Mn% |
P% |
| Run Of Mine (ROM) |
37.00 |
43.52 |
2.21 |
0.02 |
0.03 |
| Upgraded Product through the Gravity Separator (After two cycles) |
67.29 |
2.38 |
0.50 |
0.02 |
0.01 |
The table below sets out VALE’s product specification for the nearby Itabira Mine’s standard sinter feed (Southern System) as a comparison to the potential product specification for Liberdade (source CVRD 2006 Iron Ore Products).
VALE’s Itabira Mine -standard sinter feed specifications (Southern System)
| |
Fe% |
SiO2% |
Al2O3% |
Mn% |
P% |
| VALE – Standard Sinter Feed Specifications |
66.00 |
3.60 |
0.70 |
0.20 |
0.027 |
Soft, friable properties of ore, upgrades to high grade, low contaminant product after simple gravity beneficiation process
LOW COST MINING
Initial investigations by Centaurus suggest low mining and processing costs are possible at the Project. Small scale trial mining on the granted mining lease (Mining Lease 4655/1961) to produce samples for beneficiation has confirmed that the friable ore type (itabirite) is very easy to mine and does not require drilling and blasting, thereby reducing the mining costs. The entire resource is contained within 50 metres from surface and is hosted in decomposed, deeply weathered saprolitic schist and gneissic material. The layered itabirite iron formation is flat lying to gently dipping and is therefore amenable to shallow, low cost open pit mining.
Inferred Resource Ore Blocks overlaid on Total Magnetic Intensity Image (TMI) illustrating the correlation between highly magnetic anomalies and ore blocks, and highlighting potential extensions to the resource.
