Development & History
From the 1950's to 1980's, the Polish State Geological Survey carried out studies in the area of Project Olza, obtaining extensive geological information by means of diamond drilling. The results of this work indicated the presence of significant zinc-lead mineral deposits. Several historical estimates of resources were completed under a Soviet-era classification system.
From mid-2011 to early 2013, Rathdowney completed a successful campaign of confirmatory drilling focused along a trend on the Zawiercie and Rokitno concessions. The current inferred mineral resource of 24.4 million tonnes grading 7.02% Zn+Pb (at a 2% Zn cut-off) is based on both Rathdowney and historical drilling, including additional historical data received to July 2014.
Initial metallurgical test work on a composite sample from Rathdowney's drill holes in the resource-area shows that standard flotation treatment will result in two high quality concentrates.
Rathdowney's current program is designed to advance project evaluation and development planning, and to support permitting as prescribed for projects in Poland.
Based on an estimate by D. Gaunt, PGeo., of Hunter Dickinson Services Inc. (effective date July 16, 2014), a QP who is not independent of Rathdowney. The estimate at a 2% Zn cut-off was audited and verified by L. Roberts, MAusIMM(CP) of SRK, who is the independent QP for the estimate in the PEA.
PRELIMINARY ECONOMIC ASSESSMENT
In April 2015, Rathdowney announced the result of a Preliminary Economic Assessment (PEA) of Project Olza conducted by independent international engineering specialists, led by SRK Consulting (UK) Ltd with contributions by Melis Engineering Ltd . Assumptions for the PEA incorporate median zinc and lead metal price forecasts of over 30 independent banks and investment dealers, and include $1.10/lb in Year 1 and 2 and $1.00/lb in the remaining life of mine (LOM) for zinc; and $1.09/lb in Year 1, $1.00/lb in Year 2 and $0.95/lb in the remaining LOM for lead. Assumptions used for corporate income taxes and royalties are consistent with current laws in Poland.
Key financial results (in US dollars and metric units) include:
Internal Rate of Return (IRR) of 30% and Net Present Value (NPV) at an 8% discount rate of $170 million with payback in 2.4 years
Initial capital cost of $227 million with sustaining capital cost of $51.1 million
Total operating cost of $62.90/t milled includes on-site costs of $47.42/t and off-site costs of $15.48/t*
*Total Off-Site includes Treatment Charges/Recovery Charges ("TC/RC"), transportation, handling and freight costs as per the PEA; TCRC's as per Q1 2017 market costing projections ($120/t for zinc; $120/t for lead).
The PEA development scenario is a conventional underground mine and processing facility at a rate of 6,000 tonnes per day or 2.16 million tonnes per year. The mine would be accessed by two declines from surface, which enhances the construction timeline and provides for long term operational efficiencies. The PEA incorporates construction of a processing facility utilizing semi-autogenous grinding (SAG) and ball milling, followed by standard flotation, to produce marketable zinc and lead concentrates that would be shipped to smelters.
The metal production statistics (see below) from the PEA indicate Project Olza has the potential to become an important zinc and lead producer.
The project life based on the current mineral resource is eight years, but extensive historical drilling conducted by the Polish government has documented widespread zinc-lead mineralization outside of the current resource-area. In the areas where confirmatory drilling was carried out by Rathdowney, there has been good correlation with the results from the historical drilling. The potential to increase mineral resources and extend the project life with additional drilling is considered to be excellent.
The PEA is preliminary in nature and includes Inferred Mineral Resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as Mineral Reserves. There is no certainty that the preliminary economic assessment will be realized. Mineral Resources are not Mineral Reserves because they do not have demonstrated economic viability.
Qualified Persons for the PEA technical report are C. Bray, MAusIMM(CP), L. Roberts, MAusIMM(CP), C. Bonson, EurGeol, P.Geo., H. El Idrysy, CGeol, FGS, and K. Czajewski, P.Eng, of SRK Consulting (UK) Ltd and L. Melis, P.Eng, of Melis Engineering Ltd.