International Northair Mines Files NI 43-101 Technical Report on SEDAR for Maiden Resource Calculation of La Cigarra Silver Project, Mexico

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VANCOUVER, BRITISH COLUMBIA--(Marketwired - Apr 11, 2013) - International Northair Mines Ltd. (TSX VENTURE:INM) (the "Company" or "Northair") is pleased to announce that, in compliance with National Instrument ("NI") 43-101, it has filed on SEDAR the Technical Report for the maiden resource estimate, as released on February 26, 2013, for its La Cigarra silver project located in north central Mexico. The Technical Report titled "San Gregorio / Las Carolinas Resource Technical Report, La Cigarra, Chihauhua, Mexico" was completed by JDS Energy and Mining Inc. with the resource estimate by Arseneau Consulting Services ("ACS") and is available on the Company's website by clicking the following link:
www.internationalnorthair.com/i/pdf/2013-04-10_JDS_La_Cigarra_Resource_Report.pdf

Resource Estimate

The resource estimate contained in the Technical Report was calculated based on results from 143 of 154 holes totaling 25,576 metres drilled along the open ended La Cigarra mineralized system which has a drilled strike length of at least three (3) kilometres. The 143 holes included in this initial resource estimate were positioned within a potentially surface minable mineralized area comprised of the San Gregorio and Las Carolinas mineralized zones, which combined form a total strike length of 2.1 kilometres within the known three (3) kilometres. The mineral resource estimate was constrained by a Whittle™ pit shell at an economic cutoff grade of 30 g/t of silver and metallurgical recoveries of 84% silver. Highlights of the mineral resource estimate are as follows:

  • Measured and Indicated mineral resources of 50,494,000 ounces of silver within 20,755,700 tonnes at an average grade of 76 g/t silver;
  • Inferred mineral resource of 3,515,900 ounces silver within 1,780,000 tonnes at an average grade of 61 g/t silver;
  • Higher than average grade zones outcrop, which could improve the assumed project economics in the early years;
  • Significant by-products include 40,100 ounces of gold in the measured and indicated categories as well as appreciable lead and zinc values, as provided in mineral resource estimate tables noted below.

A summary of the mineral resource estimate contained in the resource shell as calculated by ACS at a 30 g/t silver cut-off grade and metallurgical recoveries of 84% silver is listed below:

Category Tonnes* Ag
(g/t)
Au
(g/t)
Pb
(%)
Zn
(%)
Ag Oz Au Oz Pb Lbs Zn lbs
Measured
6,235,000 65 0.06 0.10 0.16 13,090,800 12,100 13,161,500 21,706,600
Indicated
14,520,700 80 0.06 0.10 0.14 37,402,800 28,100 32,924,700 45,983,100
M + I 20,755,700 76 0.06 0.10 0.15 50,494,000 40,100 46,086,200 67,689,700
Inferred
1,780,150 61 0.05 0.10 0.12 3,515,900 3,000 3,959,300 4,865,700
Note:* Mineral resources are reported in relation to a conceptual pit shell at a 30 g/t silver cut-off. Mineral resources are not mineral reserves and do not have demonstrated economic viability. All figures are rounded to reflect the relative accuracy of the estimate. All composites have been capped where appropriate.

The mineral resources of the La Cigarra Project are sensitive to cut-off grade. To illustrate this, the block model quantities and grade estimates within the conceptual pit are presented in the following table at different cut-off grades.

CLASS Cut-off Tonnes
(000)
Ag
(g/t)
Ag
(oz)
Au
(g/t)
Pb
(%)
Zn
(%)
Measured >100 Ag g/t 803 137 3,548,500 0.08 0.14 0.17
> 50 Ag g/t 3,571 85 9,741,200 0.07 0.11 0.18
> 40 Ag g/t 4,753 75 11,434,300 0.06 0.11 0.17
>30 Ag g/t 6,235 65 13,090,800 0.06 0.1 0.16
>20 Ag g/t 8,220 56 14,676,900 0.06 0.08 0.14
> 10 Ag g/t 11,689 43 16,301,200 0.05 0.07 0.12
Indicated >100 Ag g/t 3,578 156 17,968,000 0.08 0.15 0.19
> 50 Ag g/t 9,235 104 30,834,800 0.07 0.12 0.17
> 40 Ag g/t 11,273 93 33,763,100 0.06 0.11 0.16
>30 Ag g/t 14,521 80 37,402,800 0.06 0.1 0.14
>20 Ag g/t 19,539 66 41,381,600 0.06 0.09 0.13
> 10 Ag g/t 27,714 51 41,381,600 0.05 0.07 0.11
Inferred >100 Ag g/t 160 139 717,400 0.06 0.15 0.18
> 50 Ag g/t 936 82 2,467,000 0.06 0.12 0.15
> 40 Ag g/t 1,252 73 2,920,200 0.06 0.11 0.14
>30 Ag g/t 1,780 61 3,515,900 0.05 0.1 0.12
>20 Ag g/t 2,497 51 4,091,200 0.05 0.09 0.11
> 10 Ag g/t 3,386 41 4,689,300 0.05 0.08 0.09
Note: Figures presented in this table for cut-off values below 30 g/t silver should not be misconstrued with a Mineral Resource Statement. The figures are only presented to show the sensitivity of the block model estimates to the selection of cut-off grade.

The development of the comparative tables has relied on the work of experts as described in this release. The following factors should also be noted:

  • Mineral resources were estimated in conformance with the CIM Mineral Resources definitions referred to in National Instrument 43-101, Standard of Disclosure for Mineral Properties;
  • The resource estimate considered the results of 154 drill holes totaling (25,576 metres) and was calculated by using 143 of these holes;
  • Mineral resources were estimated by ordinary kriging in 10x10x10 metre blocks. Grades were capped to 500 g/t silver in the high grade portion of the mineralization:
  • Mineral resources were classified as Measured if at least three (3) drill holes were found within a 75 x 50 x 25 metre search radius. Blocks were classified as Indicated if two (2) drill holes were found within a 75x50x25 metre search radius and blocks were classified as Inferred if at least three (3) drill holes were found within a 100x75x30 metre search radius;
  • The "reasonable prospects for economic extraction" requirement generally implies that the quantity and grade estimates meet certain economic thresholds and that the mineral resources are reported at an appropriate cut-off grade taking into account extraction scenarios and processing recoveries. In order to meet this requirement, ACS considers that major portions of La Cigarra mineralization are amenable for open pit extraction;
  • In order to determine the quantities of material offering "reasonable prospects for economic extraction" by an open pit, ACS, with the assistance of JDS, used Whittle™ pit optimization software and reasonable mining assumptions to evaluate the proportions of the block model (Measured, Indicated and Inferred blocks) that could be "reasonably expected" to be mined from an open pit;
  • The optimization parameters, found in the table below, were selected based on experience and benchmarking against similar projects. The reader is cautioned that the results from the pit optimization are used solely for the purpose of testing the "reasonable prospects for economic extraction" by an open pit and do not represent an attempt to estimate mineral reserves. There are no mineral reserves on the La Cigarra Project. The results are used as a guide to assist in the preparation of a mineral resource statement and to select an appropriate resource reporting cut-off grade.
Parameter Value Unit
Silver Price $ 29.20 US$ per ounce
Lead Price $ 1.00 US$ per pound
Zinc Price $ 0.95 US$ per pound
Mining Cost $ 2.00 US$ per tonne mined
Processing (Sulphide material) $ 15.00 US$ per tonne of sulphide feed
Processing (Oxide Material) $ 12.00 US$ per tonne of oxide feed
General and Administrative $ 1.00 US$ per tonne of feed
Overall Pit Slope 45 degrees
Silver Flotation Recovery 84 Percent
Lead Flotation Recovery 75 Percent
Zinc Flotation Recovery 60 Percent
Silver Leach Recovery 90 Percent
Lead Payable 95 Percent
Silver Payable in Lead Conc. 95 Percent
Zinc Payable 85 Percent
Silver Payable in Zinc Conc. 70 Percent
Silver Dore Payable 100 Percent

Immediate Resource Expansion Potential

Immediate exploration potential at La Cigarra exists within and adjacent to the current resource area (between sections 6+00S in Las Carolinas and 3+50N in San Gregorio) at a 30 g/t silver cut-off as presented in the table below. The potential silver quantity and grade is conceptual in nature as there has been insufficient exploration to define a mineral resource and it is uncertain that further exploration will result in the target being delineated as a mineral resource. This exploration quantity and grade was determined based on a single drill hole within the 100m search ellipse.

Immediate Exploration Potential adjacent and within the San Gregorio/Las Carolinas Zones, La Cigarra Project

Potential In-Situ Grade Potential Contained Metal
Category Tonnes
(000)
Ag
(g/t)
Au
(g/t)
Pb
(%)
Zn
(%)
Ag
(oz)
Exploration Potential 3,000 to 4,500 65 to 75 ~0.06 0.09 to 0.1 0.13 to 0.14 6,000,000 to 10,000,000

Click the link below to view a long section covering the San Gregorio and Las Carolinas zones demonstrates the meaningful drill intersections that encountered mineralization below and adjacent to the optimized pit, which were not included in the calculation of the resource estimate.
www.internationalnorthair.com/i/maps/2013-04-10-La_Cigarra-Long_Section.jpg

Furthermore, considerable resource exploration potential exists along the open continuous six (6) kilometre long La Cigarra mineralized system. This potential is in part supported by soil sampling along trend of the system, comprising the La Borracha Zone to the north (where nine (9) drill holes have intercepted significant silver mineralization) and the Las Venadas Zone to the south (which has returned surface silver values of up to 233 g/t silver over 2.5 metres). The defined target zone at Las Venadas covers an area of approximately 230 metres by 90 metres.

In addition, numerous other target areas within the remaining 32,000 hectare land package could host significant mineralization as evidenced by a cluster of historic workings and mineralized grab samples obtained from preliminary prospecting.

QA/QC

This news release has been prepared in accordance with Canadian regulatory requirements set out in National Instrument 43-101 and approved by Fred Hewett, the Company's President and CEO, and a Qualified Person under NI 43-101.

The resource estimation work was completed by Dr. Gilles Arseneau, P.Geo. of Arseneau Consulting Services and an independent Qualified Person as defined under NI 43-101.

About International Northair Mines Ltd.

Northair is a mineral exploration company engaged in the acquisition and development of gold and silver properties in Mexico. The Company is currently focused on advancing its La Cigarra silver project located in the state of Chihuahua, which hosts a robust NI 43-101 compliant silver resource estimate that also contains appreciable lead, zinc and gold values. Excellent exploration potential exists to the north of the deposit within the La Borracha Zone (where nine (9) drill holes have intercepted significant silver mineralization) and to the south where the extension of the La Cigarra structure has demonstrated a strong mineralized system with numerous drill targets. The permissive geology and attractive surface sampling results present a compelling opportunity to expand the known resource. The Company is presently prioritizing target areas for an expected 2013 drill program.

ON BEHALF OF THE BOARD,

INTERNATIONAL NORTHAIR MINES LTD.

Fred G. Hewett, P.Eng., President & CEO

This news release may contain forward looking statements which are not historical facts, such as ore reserve estimates, anticipated production or results, sales, revenues, costs, or discussions of goals and exploration results, and involves a number of risks and uncertainties that could cause actual results to differ materially from those projected. These risks and uncertainties include, but are not limited to, metal price volatility, volatility of metals production, project development, ore reserve estimates, future anticipated reserves and cost engineering estimate risks, geological factors and exploration results. See Northair's filings for a more detailed discussion of factors that may impact expected results.

This news release does not constitute an offer to sell or solicitation of an offer to sell any securities in the United States. The securities have not been and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act") or any state securities laws and may not be offered or sold within the United States or to U.S. Persons unless registered under the U.S. Securities Act and applicable state securities laws or an exemption from such registration is available.

Contact:
International Northair Mines Ltd.
Fred Hewett
President & CEO
604-687-7545 or 1-888-338-2200
International Northair Mines Ltd.
Chris Curran
Manager, Corporate Communications
604-687-7545 or 1-888-338-2200
International Northair Mines Ltd.
Brent Levenstadt
Investor Relations Associate
604-687-7545 or 1-888-338-2200
604-689-5041
info@northair.com
www.internationalnorthair.com

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