Mr. Graham Downs reports
ATAC ANNOUNCES POSITIVE RESULTS OF AN UPDATED PEA AT THE HIGH-GRADE TIGER GOLD DEPOSIT, RACKLA GOLD PROJECT, YUKON
Atac Resources Ltd. has completed an updated preliminary economic assessment for the Tiger deposit, located at the western side of the company's 100-per-cent-owned Rackla gold project, Yukon.
The 2016 PEA has incorporated results of geotechnical and infill drilling conducted in 2015 and metallurgical studies completed in early 2016. Key changes to the 2014 PEA consist of the inclusion of both oxide and sulphide resources and the adoption of a simplified year-round agitated tank carbon-in-pulp (CIP) leaching process. The 2014 PEA (see Atac news release dated July 23, 2014) only investigated the extraction of oxide resources by means of a seasonal hybrid heap-leach and agitated tank carbon-in-leach (CIL) process.
PEA highlights -- 2016
Highlights from the 2016 PEA, with the base-case gold price of $1,250 (U.S.)/ounce and an exchange rate of $1.00 equal to 78 U.S. cents are as follows:
- Net present value (5 per cent)
of $106.6-million and an internal rate of return of 34.8 per cent before tax, and an NPV
(5 per cent)
of $75.7-million and an IRR of 28.2 per cent after tax, with an all-in sustaining cost of $864 (U.S.)/ounce;
- Compared with the 2014 PEA, the 2016 PEA extends the mine life by two years, more than doubles the pretax NPV
(5 per cent)
and increases the pretax IRR by 4.8 per cent;
- Approximately 302,307 ounces of gold produced at an average undiluted grade of 3.81 grams per tonne gold;
- Total project life increases to approximately nine years, including one year of construction and prestripping, followed by six years of owner-operated open-pit mining and two years of reclamation;
- Preproduction capital cost of $109.4-million and life-of-mine (LOM) sustaining capital costs totalling $8.3-million.
"We are very pleased to have doubled the pretax NPV to over $100-million and to have been able to improve on every other 2014 PEA metric. The future development of the Tiger deposit would bring critical infrastructure, including tote road access, to the Rackla gold project. Exploration will begin shortly at the newly discovered 10-square-kilometre Airstrip gold anomaly and elsewhere within the Rau trend with the objective of identifying additional nearby resources. Atac will continue to explore opportunities to advance or monetize the Tiger deposit through sole development or joint venture," stated Graham Downs, president and chief executive officer of Atac. "Atac remains committed to further advancing the entire Rackla gold project, including the Carlin-type targets within the Nadaleen trend. Drilling is scheduled to begin soon at the Orion discovery, where one of the last holes of 2015 (ARB-15-026) intersected 3.79 g/t gold over 47.24 metres."
Tetra Tech WEI Inc. (mining, processing, infrastructure, financial analysis) was contracted to complete the PEA in co-operation with Blue Coast Metallurgy Ltd. (metallurgy), Knight Piesold Ltd. (tailings), Resource Strategies (environmental and permitting), Giroux Consultants Ltd. (mineral resource) and Archer, Cathro & Associates (1981) Ltd. (geology, mineralization and exploration).
COMPARISON OF KEY RESULTS AND PARAMETERS
2014 PEA 2016 PEA*
Gold price (US$/oz) $1,250 $1,250
Exchange rate (US$/CA$) 0.92 0.78
Pretax NPV (5%) (millions) $52.2 $106.6
Pretax IRR 30.0% 34.8%
Posttax NPV (5%) (millions) $33.67 $75.71
Posttax IRR 21.5% 28.2%
Recovered gold 221,558 oz 302,307 oz
Average gold grade 3.72 g/t 3.81 g/t
Average oxide recovery 89.8% 90.3%
Average sulphide recovery 0% 57.7%
Preproduction capital (millions) $92.3 $109.4
Sustaining capital (millions) $26.5 $8.3
Payback (pretax) 2.2 years 1.85 years
Payback (posttax) 2.6 years 1.93 years
Preproduction period 1 year 1 year
Mine life 4 years 6.2 years
Closure period 2 years 2 years
Project life 7 years 9.2 years
Process Hybrid CIL/heap leach CIP
Production rate 3,300 tpd 1,500 tpd
Operational period Seasonal (158 days) Year-round (365 days)
Strip ratio 5.6:1 4.9:1
Access method Winter road Tote road
* The 2016 PEA does not consider silver resources.
Key improvements over the 2014 PEA
The 2016 PEA envisions a conventional year-round operation and has improved upon all aspects of the 2014 PEA. Key improvements include:
- Increased the pretax NPV
(5 per cent)
by $54.4-million;
- 36-per-cent increase in total recovered ounces;
- Project life extended by two years;
- Pretax payback period reduced to 1.85 years;
- Tote road access: supports year-round operations and simplifies project logistics;
- 100-per-cent CIP process: simplified and conventional process allows for year-round operations and reduces LOM sustaining capital costs;
- Relocated and consolidated project infrastructure: reduced overall environmental footprint and haulage costs;
- Year-round operations: alleviates logistical and staffing challenges associated with seasonal access and operations.
Economic results and sensitivities
The tables demonstrate the sensitivity of the Tiger deposit pretax economics to changes to the price of gold and exchange rates. The base case, highlighted in the tables, assumes $1,250 (U.S.) per ounce of gold at an exchange rate of $1.00 equals 78 U.S. cents.
SUMMARY OF GOLD PRICE SENSITIVITY
Gold Price (US$/oz) $1,200 $1,250 $1,300
Pretax cumulative net cash flow ($M) $130.1 $149.4 $168.7
Pretax NPV (5%) ($M) $90.8 $106.6 $122.3
Pretax IRR 30.8% 34.8% 38.8%
SUMMARY OF EXCHANGE RATE SENSITIVITY
Exchange rate (US$/Cdn$) 0.76 0.78 0.80
Pretax cumulative net cash $162.0 $149.4 $137.4
flow ($M)
Pretax NPV(5%) ($M) $116.9 $106.6 $96.8
Pretax IRR 37.4% 34.8% 32.3% Mining and processing
The Tiger project has been modelled as an owner-operator, conventional truck-and-shovel open-pit mining operation with a conventional CIP gold recovery process. Year-round operations would be supported via a 68-kilometre tote road, which connects the project to the Yukon highway system, near Keno City.
Mineralized material will be loaded into 40-tonne articulated trucks and delivered to the process plant, located one km southwest of the pit. High-grade mineralized material will be sent directly to the primary crusher, while low-grade stockpile material will be stored close to the primary crusher. Waste material from the pit will be stored in two waste dumps, located at the northwest and southwest sides of the pit. A total of 3.2 million tonnes (Mt) of the mineral resource and 15.6 Mt of waste rock will be produced from the pit during the seven years of mining operations and prestripping. The LOM average gold grade of mined oxide and sulphide resources is 4.06 grams per tonne and 2.99 g/t, respectively. The LOM stripping ratio (defined as waste material mined divided by mineral resources mined) is 4.9.
Due to the soft nature of the mineralization and host rock, a single stage of crushing will be performed by an MMD sizer. Crushed material will be ground to 80 per cent passing 75 microns using a semi-autogenous grinding mill and a ball mill in series before cyanide leaching in a conventional CIP circuit. The leach tailings will be detoxified and stored in a lined facility within the Tiger Valley. Gold will be refined into dore bars on-site through a standard adsorption, desorption and recovery treatment. Based on the results of metallurgical testwork and the mining schedule, projected LOM average recoveries are 90.3 per cent for oxide mineralization and 57.7 per cent for sulphide mineralization.
The processing plant will operate year-round at a rate of 1,500 tonnes per calendar day and will achieve full throughput in year two. Peak annual production will be approximately 86,555 ounces of gold in year two, with an LOM average annual production of approximately 50,000 ounces gold, excluding the final year which will operate for a reduced period.
Capital and operating costs
Total LOM capital costs are $117.7-million, with $109.4-million in preproduction costs and $8.3-million in sustaining capital. To minimize initial capital costs, the PEA has assumed that modular equipment would be used where possible and that some equipment and facilities will be leased.
The tables summarize the project capital and operating costs.
PREPRODUCTION AND SUSTAINING CAPITAL COSTS*
Area Preproduction Sustaining LOM
($M) ($M) ($M)
Site infrastructure $8.1 - $8.1
Tote road $11.0 - $11.0
Open-pit mining** $13.2 $0.03 $13.2
Materials crushing and handling $2.0 - $2.0
Process plant $29.7 - $29.7
Tailings and water management $7.9 $6.1 $14.0
Project indirects $19.8 - $19.8
Owner's costs $1.2 - $1.2
Contingencies*** $16.5 $2.2 $18.7
Total $109.4 $8.3 $117.7
* Totals may not add exactly due to rounding.
** Includes capitalized preproduction mining costs. Major mining equipment
is leased.
*** Contingencies were factored on an area-by-area basis depending on the
detail level of each estimate.
OPERATING COSTS
Description LOM average
Mining cost ($/t mined)* $4.31
Processing cost ($/t processed) $26.98
G&A ($/t processed) $12.38
Surface services ($/t processed) $3.80
Equipment leasing ($/t processed) $1.68
*Not including capitalized preproduction mining costs.Opportunities to enhance value
Atac is very pleased with the increased value of the Tiger deposit shown in this updated PEA relative to the initial 2014 PEA and believes that opportunities exist to further enhance the economics of the project. Some key opportunities include:
- Significant potential exists to increase the resource base and life expectancy of the project with the exploration of more than 15 early-stage satellite oxide gold targets and geochemical anomalies;
- Additional geotechnical studies may permit steeper pit slopes, which would further reduce the strip ratio and could potentially allow additional known resources to be accessed;
- Additional diamond drilling within the sulphide zone would convert inferred resources to the indicated category and could potentially lead to the inclusion of additional known sulphide resources;
- Additional diamond drilling targeting high-grade oxide structures (including 162.0 grams per tonne gold over 2.90 metres in Rau-09-019) could better define high-grade domains for inclusion in future resource estimates.
Environmental and community engagement
Since 2008, Atac has completed comprehensive water, heritage, wildlife and fisheries studies. Atac will continue environmental baseline work and continuing studies as it advances the Tiger deposit and other targets throughout the Rackla gold project.
Community and first nation engagement began in 2008, and an exploration co-operation agreement with the first nation of Na Cho Nyak Dun (NNDFN) was signed in 2010. This exploration co-operation agreement with the NNDFN provides a framework within which exploration activities and environmental regulatory process on Atac's Rackla gold project have been and will continue to be carried out. The Rackla gold project lies exclusively within the traditional territory of the NNDFN.
Metallurgy
Metallurgical testwork has been previously conducted in several phases on both the oxide and sulphide material, including work by G&T Metallurgical, SGS Canada and Kappes, Cassiday & Associates in support of the 2014 PEA. Additional variability cyanide leach testwork was conducted on the Tiger deposit by Blue Coast Research Ltd. in 2016 for the updated PEA. Bottle-roll testing was conducted on eight oxide and eight sulphide composites, and master composites samples. Samples were selected to evaluate potential variability in grade and mineralization throughout the deposit. Oxide recoveries from 24-hour bottle-roll tests ranged from 77 per cent to 98 per cent. Sulphide recoveries from 24-hour bottle-roll tests ranged from 13 per cent to 88 per cent.
Mineral resources
The mineral resource estimate used in the updated PEA was completed by Gary Giroux, PEng, MASc (Giroux Consultants Ltd.), using 6,222 assays taken from 150 diamond drill holes, totalling 26,844 metres. The effective date of this mineral resource estimate is Oct. 28, 2015. A 3-D solid model was constructed to constrain oxide and sulphide mineralization.
Gold distribution, within the mineralized solids, was examined using a lognormal cumulative frequency plot to determine appropriate capping levels. Three-metre composites were formed, honouring solid boundaries, using the capped assay data. Ordinary kriging was used to interpolate gold and silver values into a five m by five m by five m block model.
Mineral resources are reported at a 0.5 g/t cut-off in oxides and one g/t cut-off in sulphides are reported in the table. These cut-off grades were selected based on comparison to other analogous deposits.
COMBINED OXIDES AND SULPHIDE RESOURCE
Type Classification Au cut-off Tonnes greater than cut-off
(g/t)
Oxides Measured 0.50 2,600,000
Indicated 0.50 1,720,000
Sulphides Indicated 1.00 1,360,000
Total M+I 5,680,000
Oxides Inferred 0.50 280,000
Sulphides Inferred 1.00 2,950,000
Total Inferred 3,230,000
Grade greater than cut-off Contained metal
Type Au Ag Au Ag
(g/t) (g/t) (oz) (oz)
Oxides 3.10 4.77 259,100 398,700
2.47 4.10 136,300 226,700
Sulphides 2.07 0.56 90,300 24,500
Total 2.66 3.56 485,700 649,900
Oxides 1.52 5.67 13,700 51,000
Sulphides 1.84 0.47 174,800 44,600
Total 1.81 0.92 188,500 95,600
The primary difference between this mineral resource and the mineral resource used in the 2014 PEA is an increase in measured resources within the oxide domain. There is little difference in the total tonnes and contained ounces of gold between the two mineral resources.
Tiger tote road
Access to the Rau trend and Tiger gold deposit, 55 km northeast of Keno City, would be by means of a tote road, which Atac intends to permit and construct to support advanced exploration activities. The proposed tote road would branch off the Hanson Lake Road west of Keno City and is envisioned as a gated, single-lane (five m wide) and radio-controlled road suitable for vehicles that support advanced exploration at the Tiger deposit and throughout the Rau trend. The total length of the tote road would be approximately 68 km and would consist of 51 km of new road and upgrading of 17 km of pre-existing winter road.
For the purposes of this PEA, the full cost of the tote road is included in the preproduction capital costs.
Atac has been active in preparing for permitting the tote road to the Rackla gold project. Discussions regarding access and development of the Tiger deposit with the NNDFN, local communities and other interested parties have been continuing for more than seven years. Recent meetings in March and April, 2016, included several town meetings in Mayo and Keno City to discuss the proposed tote road. Details of this consultation can be found on Atac's website. NNDFN and community consultation is continuing.
Qualified persons
The reader should be cautioned that the PEA is preliminary in nature. It 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 results of the PEA will be realized.
A technical report supporting the PEA in accordance with National Instrument 43-101 will be filed on SEDAR and Atac's website within 45 days. Further details regarding the 2011 mineral resource and the 2014 PEA can be found in the technical reports dated Nov. 15, 2011, and Sept. 4, 2014, which are both filed on SEDAR and Atac's website.
The PEA was prepared under the direction of Tetra Tech WEI, in co-operation with other industry consultants, all of whom are qualified persons under terms of National Instrument 43-101, and have reviewed the technical content of this press release and approved its dissemination. QPs contributing to the PEA are listed in the table.
QPS CONTRIBUTING TO THE PEA
Qualified person, designation Company
Dr. Sabry Abdel Hafez, PhD, PEng Tetra Tech WEI
Hassan Ghaffari, PEng, MASc Tetra Tech WEI
Dr. John Huang, PhD, PEng Tetra Tech WEI
Chris Martin, CEng Blue Coast Metallurgy
Gary Giroux, PEng, MASc Giroux Consultants
Bruno Borntraeger, PEng Knight Piesold
Rob McIntyre, RET Resource Strategies
Matthew Dumala, PEng Archer, Cathro & Associates
Mr. Dumala is the company's designated QP for this news release within the meaning of National Instrument 43-101, and has reviewed and validated that the information contained in the release is consistent with that provided by the QPs responsible for the PEA.
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