Andover Ventures Announces Preliminary Economic Assessment for Burgin Extension Deposit, East Tintic Mining District, Utah, USA
VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 12/07/11 -- Andover Ventures Inc. ('Andover' or the 'Company') (TSX VENTURE: AOX)(OTCBB: AOVTF)(FRANKFURT: R2X) is pleased to announce a completed 43-101 Preliminary Economic Assessment (PEA) of the Burgin Extension deposit owned by Chief Consolidated Mining Company, ('Chief') (in turn approximately 78.5% owned by Andover). This report is the first National Instrument 43-101 compliant economic estimate of the Burgin project.
The Burgin property located about 60 miles in a straight line southwest of Salt Lake City, Utah, USA, consists of 527 acres that are a portion of a total of approximately 16,000 acres of adjacent land owned or controlled by Chief in the Tintic and adjacent East Tintic Mining Districts, Utah, USA. These two districts were mined historically for polymetallic massive sulfide replacement and gold-silver fissure vein deposits.
The total metal mined from the Tintic and East Tintic districts between 1869 and 1976 is as follows: 16.5 million tons containing 250 million ounces of silver, 2.3 million ounces of gold, 2.2 billion pounds of lead, 350 million pounds of zinc, and 250 million pounds of copper. Deeper porphyry copper-gold targets in the East Tintic district are currently being drilled by Kennecott Exploration Company ('Kennecott') a division of Rio Tinto plc, in a joint venture with Chief.
The Company engaged Mine Development Associates ('MDA') of Reno, NV, USA to complete both a Resource Estimate (completed in June - press release 06.22.2011), and a Preliminary Economic Assessment in accordance with National Instrument 43-101 on the Burgin Extension deposit. The PEA technical report was completed on December 2, 2011 and will be posted on the Company's website at www.andoverventures.com and SEDAR at www.sedar.com within 45 days.
The Burgin Extension deposit is a high grade silver-lead-zinc project and is found within a 3,000ft-long mineralized corridor along the East Tintic thrust fault (See Andover news release and update to shareholders, September 22, 2010). In addition to the Burgin Extension deposit, which is open on-strike and down dip, a number of other blind targets were discovered to the east and to the north along the corridor by either Kennecott or Sunshine Mining Company ('Sunshine') or Chief. These targets include the adjacent 12-48 and 274 Zones to the east, Zone A, Footwall, 50-02, and Ball Park targets to the north. None of these targets are included in the reported Resource Estimate. They were discovered by underground drilling and development. Underground drilling access could change the size and scope of the project substantially as it moves towards pre-feasibility and feasibility.
Mineral Resource Estimate
The resource estimate by MDA that is the focus of this Technical Report is based on a total of 109 holes drilled by Kennecott / Bear Creek Mining Corporation, Sunshine, Chief, and Andover into the Burgin Extension deposit.
The Burgin Extension Indicated and Inferred Resources total 2,277,000 tons at a 5.0 ounce per ton silver equivalent cutoff grade, as presented in Table 1.
The stated resource is fully diluted to 10ft by 10ft by 10ft blocks and tabulated on silver-equivalent ('AgEq') grade cutoff of 5.0 oz AgEq/ton that is reasonable for deposits of this nature and for the expected mining conditions and methods. The AgEq grade is calculated using the individual silver, lead, and zinc grades of each block. The gold content in each block is not used in the AgEq calculation due to the uncertain metallurgy associated with this metal. Metal prices used in the calculation are $18.00 per ounce silver, $1.00 per pound lead and $1.00 per pound zinc. Metal recovery factors for silver and lead are both 90% while the zinc recovery is 60%.
The estimate is constrained by a 3-dimensional geologic model which includes the structurally-controlled basal dolomite contact, the primary structures which localize mineralization, and unique low- medium- and high-grade mineral domains for each metal. Length-weighted composites honoring all mineral domain contacts, and with a maximum length of 5 feet, were used in the estimate. Grade estimation is by Inverse Distance Cubed (ID3) with Ordinary Kriging (OK) and Nearest Neighbor (NN) estimates run as checks. Two search passes were used and the estimation within each mineral domain used only those composites coded to that respective domain.
Though mineralization was modeled into and through areas of known historic underground mining, none of the mineralized blocks above the 1300 level workings (the lowest known level of historic activity) were included in the resource due to uncertainty in the location and extent of the historic mining activity.
Preliminary Economic Assessment
Summary
Highlights from the PEA include the following:
-- Base case using long term metal prices (three year average):
- pretax net present value (5%) of $185 Million US with an internal rate
of return of 37.79% and cash flow of $278.6 Million US.
-- Base case plus metal price increases of 30%:
- pretax net present value (5%) of $335 Million US with in internal rate
of return of 55.86% and a cash flow of $483 Million US.
-- Capital Cost Estimates and Cash Flow analysis show a capital cost prior
to production of approximately $105 Million USD and a cumulative cash
flow of $278.5 Million USD.
Processing
The mined material will be processed in an existing plant on site to produce lead and zinc concentrates. Estimated Metal recovery is 90.3% for Silver, 97.1% for Lead and 91.5% for Zinc as outlined in table 1.2.
Production Schedule
The production schedule was developed utilizing an NSR cutoff grade of $110/ton and a mining rate of 800 Tons per day or 280,000 Tons per year. The production schedule is shown in Table 1.3.
Capital Cost Estimate
The capital cost estimate includes rehabilitating the Apex headframe and shaft to gain access to the 1050 level, a new shaft with a loading pocket at the 1050 elevation, rehabilitating the 1050 level, a new ventilation raise, and a new development ramp. It may be possible to raise-bore the new shaft. Additionally the existing plant is planned to be refurbished; a facility to store about 700,000 tons of dry tailings, and a paste backfill plant will be installed. A surface de-watering well field will be installed to pump between 9,000 and 14,000 gpm of water to the surface. It is assumed that the sale of water will offset the cost of a water treatment facility and water treatment. Interest in water has been expressed by geothermal firms and others. The capital cost estimate is shown in Table 1.4.
Operating Cost Estimate
The operating cost is estimated in Table 1.5.
Economic Evaluation
MDA used the following metals prices for the study: $23.00 per ounce for silver, $0.90 per pound for lead and $0.86 per pound for zinc.
Table 1.6 shows the results of the PEA cash flow analysis.
Figure 1.1 and Figure 1.2 show the project NPV (5%) and IRR sensitivity respectively to changes in metal price, operating cost, and capital cost.
Table 1.8 shows the project sensitivity to changes in metal prices.
To view all tables and figures associated with this press release, please visit the following link: http://media3.marketwire.com/docs/AndoverTabFig.pdf
A sensitivity evaluation using a silver price of $34 per ounce and base case lead/zinc prices provided a NPV (5%) of $292.2 million and an IRR of 50.4%.
Larry Segerstrom, Andover's COO, commented, 'I am very pleased with the MDA Study. It shows the robust nature of the deposit and the excellent potential earnings it can generate. Considering that the Burgin Extension Deposit is only a part of the Burgin Complex, we are very excited about the future of the complex.'
Mineral resources that are not mineral reserves have not demonstrated economic viability, and the preliminary assessment includes inferred mineral resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the preliminary assessment will be realized.
Qualified Persons
The new Mineral Resource Estimate was completed by Paul Tietz, Senior Geologist at MDA, an independent Qualified Person as defined by National Instrument 43-101. The Preliminary Economic Estimate was completed by Neil Prenn, Principal Engineer at MDA, an independent Qualified Person as defined by National Instrument 43-101.
About Andover:
Andover Ventures is a precious and base metal exploration and development company, headquartered in Vancouver, British Columbia, Canada. Andover Ventures' holdings are located in the historic East Tintic Mining District, Utah, USA, and the polymetallic-rich Ambler Mining District, Alaska, USA.
For further information we invite you to visit us at www.andoverventures.com.
ON BEHALF OF THE BOARD
Gordon Blankstein, CEO and Chairman
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Contacts:
Andover Ventures Inc.
Richard Martens
Investor Relations
1-604-682-2168 or Int'l Toll Free: 1-800-266-4484
www.andoverventures.com