Inmet Mining Corporation

Inmet Mining Corporation

May 31, 2011 17:54 ET

Inmet Intersects 3.9% Copper Equivalent Over 124 Metres in Balboa Expansion Drilling at Cobre Panama

TORONTO, CANADA--(Marketwire - May 31, 2011) - Inmet Mining Corporation ("Inmet") (TSX:IMN) is pleased to report further results from 12 new holes drilled on the Balboa discovery, on its 100 percent owned Cobre Panama Project, located in central Panama. Balboa is a new porphyry copper gold discovery located only 1,500 metres west of the other Cobre Panama deposits. Balboa is the first anomaly drilled of several targets identified by a geophysical survey, which was conducted in August 2010 following the completion of an extensive in-fill drilling programme. The Balboa discovery is not expected to be part of the initial mine plan and should therefore not affect the timing of the review and approval of the Environmental and Social Impact Assessment, still expected in September 2010. In the near-term, subject to further studies, Balboa provides significant expansion upside for both production and mine-life.

Jochen Tilk, President and CEO of Inmet commented, "We are very excited to see Balboa grow at depth with increasing copper and gold grades. The results demonstrate that the geologic system which contains Cobre Panama is capable of producing high grade mineralization. Cobre Panama already represents a world-class deposit expected to commence construction in less than 12 months. The addition of the Balboa discovery and potentially other targets endorse our view of the outstanding potential for Cobre Panama to become one of the world's largest copper producers."

The latest assay results include the two best holes drilled to date on the Balboa discovery, as follows:

Hole CC11-010:2.32 % Cu and 2.28 g/t Au (3.89 % CuEq) over 124.3 metres,
included in a broader interval of1.41 % Cu and 1.29 g/t Au (2.30 % Cu Eq) over 221.8 metres.

Hole CC11-010 is located some 500 metres west of hole CC10-111, reported in March, and represents the furthest west and down dip intersection on the mineralized zone to date. More importantly this hole indicates increasing copper and gold grades at depth, and an increase in the gold:copper ratio.

Hole CC11-004:0.95 % Cu and 0.43 g/t Au (1.27 % CuEq) over 199.5 metres,
included in a broader interval of0.65 % Cu and 0.26 g/t Au (0.85 % CuEq) over 363.9 metres.

Hole CC11-004 is also open down dip and to the west. Lists of all 17 holes drilled and with assays received to date on Balboa are tabulated below at copper grade cut-offs of 0.15% and 0.50%.

Recognizing the importance of advancing this discovery, the Inmet Board has approved a budget of $9.0 million to support ongoing drilling in 2011 with four rigs, while two additional rigs, capable of deeper holes are on the way. We intend to drill another 20,000 metres, continuing to test the margins at 200 metre centers, with infill drilling on 100 metre centers, aiming to establish NI 43-101 compliant resources at an Indicated category. We have commenced metallurgical work to evaluate metallurgical responses to the planned Cobre Panama flow sheet. From analytical results received so far, we have not identified levels of any deleterious elements that are likely to cause concern in a final concentrate. We have drilled 19 holes to date, and the discovery covers an area of 1,000 metres by 800 metres and remains wide open to the west, northwest and southwest. The first two in-fill holes that have been drilled on 100 metre centers (also reported below) returned intersections which have confirmed spatial and grade continuity with those holes reported earlier. Based on this data, Inmet's current preliminary estimate2 is that Balboa contains minimum potential mineralization, at a range of copper cut-off grades, as follows:

Table 1: Preliminary Potential Mineralization - Balboa Zone (2)
Cu % CutoffTonnes (millions)Cu %Au g/tCu Eq % (1)Contained Cu (billions lbs)Contained Au (millions ozs)Contained CuEq (billions lbs)
greater than 0.15500 to 6000.40 to 0.500.15 to 0.190.50 to 0.604.4 to 6.62.4 to 3.65.5 to 8.2
greater than 0.30300 to 3600.55 to 0.650.20 to 0.300.70 to 0.853.6 to 5.42.1 to 3.24.5 to 6.7
greater than 0.50130 to 1700.80 to 1.000.40 to 0.501.00 to 1.302.4 to 3.61.8 to 2.73.0 to 5.0
(1)Copper Equivalent calculated using US $2.25/lb Cu, US $1000/oz Au, US $13.50/lb Mo and US $15.00/oz Ag and is not adjusted for metallurgical recoveries as these remain uncertain. Because Mo and Ag are less significant they are not included in our preliminary estimate.
(2)Under National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101), these potential tonnage and grade estimates are conceptual in nature, as there has been insufficient exploration to define a mineral resource, and it is uncertain if further exploration will result in the targeted discovery being delineated as a mineral resource.

Colin Burge, Inmet Senior Geologist and Site Technical Manager, Minera Panama SA, commented "These results are suggesting potential that we haven't seen before. Looking at Hole 10, the very high bornite content as veins and disseminations and the lack of iron pyrite suggest that we may be starting to find the core of a quality system. Our preliminary interpretation, which requires a lot more work to refine, is that the zone around Hole 10 could represent the deeper, higher grade roots of Cobre Panama."

Table 2: Assay results – Balboa Zone (> 0.15 Cu cutoff)
BHIDReleasedFromToInterval (m)Cu %Mo ppmAu g/tAg g/tCuEq(3)%
Weighted Average Grades0.45190.161.710.58
Notes: Intervals are core lengths
(3)Copper Equivalent calculated using US $2.25/lb Cu, US $1000/oz Au, US $13.50/lb Mo and US $ 15.00/ oz Ag and is not adjusted for metallurgical recoveries as these remain uncertain. The formula used is as follows Cu Eq = Cu %+ (Au g/t x 0.65) + (Mo ppm /1667) + (Ag g/t x 0.01).
Table 3: Assay Results – Balboa Zone – High Grade Zones (> 0.5% Cu cutoff)
BHIDReleasedFromToInterval (m)Cu %Mo ppmAu g/tAg g/tCuEq(3)%
Weighted Average Grades0.89120.443.291.22
Note:All of these high grade intercepts are included within the broader intervals reported in Table 2
Note:Intervals are core lengths
(3)Copper Equivalent calculated using US $2.25/lb Cu, US $1000/oz Au, US $13.50/lb Mo and US $15.00/ oz Ag and is not adjusted for metallurgical recoveries as these remain uncertain. The formula used is as follows Cu Eq = Cu %+ (Au g/t x 0.65) + (Mo ppm /1667) + (Ag g/t x 0.01).

To view "Figure 1: Plan Map- Balboa Discovery May 2011," "Figure 2: Section West East – Balboa Discovery May 2011" and "Figure 3: Section South North – Balboa Discovery May 2011", please visit the following link:


Drillcore samples from the Balboa zone were assayed at ALS Chemex Laboratories in Lima, Peru (ISO 9001:2000 Certified). Sample preparation is done at site. Duplicate and standard samples are inserted into the sample stream to provide quality control. Copper assays are by AAS after a four-acid digestion (HF-HNO3-HClO4-HCL). Gold analyses are by fire assay and AAS analysis on a 30 gram sample. Silver and molybdenum are included as part of a multi-element ICP-AES scan. Total sulphur is analyzed using a LECO induction furnace. Near-surface samples are analyzed for sequential copper to estimate the amount of leachable copper. Sulphuric, cyanide, and citric-acid soluble copper and residual copper values are reported for each sample.

Mr Colin Burge, P.Geo., Inmet Senior Geologist and on-site technical manager for MPSA and a qualified person as defined by National Instrument 43-101, has supervised the drill program and QA/QC procedures, reviewed and verified the information and is responsible for the technical content of this press release.

Webcast and conference call

A presentation accompanying this press release will be posted to the Inmet website at the start of the webcast and conference call to be held tomorrow June 1, 2011 at 8:30 am ET. The presentation will be delivered by Jochen Tilk, President and CEO and Frank Balint, Vice President Corporate Development. All participants are invited to access the call using the following coordinates:

+ 416-695-6616 (local/international) or toll free +1 800-952-6845 (North America only). No password is required for the call, and participants who choose to join the presentation by phone should download the presentation file in PDF from the Inmet website, to avoid audio and slide synchronization delays.
Participants in the webcast can log in at:

Core from the Balboa discovery will be on display at Inmet's upcoming Annual Meeting of Shareholders to be held in Toronto at the Board of Trade, East Ballroom, at 230 pm ET, June 27, 2011.

About Cobre Panama

The Cobre Panama project hosts measured and indicated mineral resources of 3.27 billion tonnes grading 0.36 percent copper, 0.06 grams per tonne gold and 0.007 percent molybdenum. These mineral resources include proven and probable mineral reserves of 2.14 billion tonnes grading 0.41 percent copper 0.07 grams per tonne of gold and 0.008 percent molybdenum. Mineral resources are quoted at a cut-off grade of 0.15 percent copper. (see table below) Mineral resources that are not mineral reserves do not have demonstrated economic viability.

We expect Cobre Panama to produce 289,000 tonnes of copper and 108,000 ounces of gold per year (open pit) during the first 16 years of a 30 year mine life. Project details including estimated capital and operating costs may be found in the 2010 Cobre Panama Front End Engineering and Design Study Executive Summary, the March 31, 2010 Mina de Cobre Panamá National Instrument 43-101 Technical Report and the project Environmental and Social Impact Assessment Executive Summary available at

Mineral resources were estimated by Robert Sim, P. Geo., of SIM Geological Inc. and Bruce Davis, Ph.D., Fellow of the AusIMM (FAusIMM), BD Resource Consulting Inc., both qualified persons under National Instrument 43-101.

Mineral reserves were estimated by William Rose, P.E., of WLR Consulting, Inc., a qualified person under National Instrument 43-101.

Mineral reserve estimates by classification
million tonnesCu
Proven and probable2,1430.410.071.430.008

These are based on the following assumptions:
Metal pricesMining costs
Copper (Cu): US $2.00 per poundUS $1.33 per tonne of material mined
Gold (Au): US $750 per ounceMilling and general and administration costs combined
Silver (Ag): US $12.50 per ounce US $5.37 per tonne of ore milled
Molybdenum (Mo): US $12.00 per pound
Mineral resource estimates by classification
million tonnesCu
Measured and indicated3,2710.360.061.30.007

Mineral resources include mineral reserves. Grades are estimated using ordinary kriging with a nominal block size of 25 metres by 25 metres by 15 metres. Resources are limited inside a pit shell defined by a copper price of US $2.30 per pound, the same operating costs used for reserves, and are tabulated at a cut-off grade of 0.15 percent copper. Mineral resources that are not mineral reserves do not have demonstrated economic viability. (from NI 43-101 Report – May 3rd, 2010)

Forward looking information

Securities regulators encourage companies to disclose forward-looking information to help investors understand a company's future prospects. This press release contains statements about our future financial condition, results of operations and business.

These are "forward-looking" because we have used what we know and expect today to make a statement about the future. Forward-looking statements usually include words such as may, expect, anticipate, believe or other similar words. We believe the expectations reflected in these forward-looking statements are reasonable. However, actual events and results could be substantially different because of the risks and uncertainties associated with our business or events that happen after the date of this press release. You should not place undue reliance on forward-looking statements. As a general policy, we do not update forward-looking statements except as required by securities laws and regulations.

About Inmet

Inmet is a Canadian-based global mining company that produces copper and zinc. We have interests in three mining operations: Çayeli (Turkey), Las Cruces (Spain) and Pyhäsalmi (Finland). We also have a 100 percent interest in Cobre Panama, a development project in Panama.

This press release is also available at

Contact Information

  • Inmet Mining Corporation
    Flora Wood
    Director, Investor Relations
    +1 416 361 4808

    Inmet Mining Corporation
    Frank Balint
    VP Corporate Development
    +1 416 860 3978