Scorpio Gold Announces Positive Feasibility Study for Processing the Heap Leach Mineral Resource at Mineral Ridge
TSX-V: SGN
1462 de la Québécoise
Val-d’Or, QC, J9P 5H4
T: 604- 678-9639
www.scorpiogold.com
News Release No. 247
Scorpio Gold Announces Positive Feasibility Study for Processing the Heap
Leach Mineral Resource at Mineral Ridge
Vancouver, October 10, 2017 - Scorpio Gold Corporation ( “Scorpio Gold ” or the “Company”) (TSX
V:SGN) is pleased to announce the results of a positive feasibility study ( “the Project”) to reprocess the
heap leach residual material at its Mineral Ridge property, located in Esmeralda County, Nevada. Scorpio
Gold holds a 70% interest in the project with joint venture partner Elevon, LLC (30%).
Brian Lock, Interim CEO comments, “I would first like to take this opportunity to thank Novus Engineering
Inc. (“Novus”), Mine Technical Services ( “MTS”), NewFields and our Scorpio Gold employees for their
dedicated effort in completing this study. The combined effort of all parties involved produced a very
thorough study of our Mineral Ridge heap leach resource and proposed milling facility. This economically
positive study provides the foundation for recovering a substantial portion of the 122 ,000 ounces of gold
resources contained on the heap leach pad. This project, when completed, will provide Mineral Ridge with
five years of additional of mine life. Additionally, due to higher expected recovery rates provided by the
new milling circuit, the Company is proceeding with a third -party analysis of its ot her known mineral
resources. When complete, and if determined economically viable, this study should add additional reserves
and further extend the Mineral Ridge life of mine. Further exploration at Mineral Ridge may also add
additional resources.”
Feasibility Study Description
About 68% recovery of gold was realized from the previous heap leach operations at Mineral Ridge. Sonic
core drilling was completed to create a mineral resource estimate from the heap pad, which was previously
issued by MTS on July 12, 2017. Independent testing of the residual heap leach material indicates 91%
recovery by further grinding the heap material and reprocessing using the carbon-in-leach (“CIL”) process.
Novus was engaged by Scorpio Gold to design a processing facility an d develop capital expenditure
(“CAPEX”) and operating expenditure ( “OPEX”) estimates related to the new processing facility.
NewFields developed the methodology for “mining” the heap residual material and for returning the tailings
material from the processing facility to the lined pad. NewFields also provided the CAPEX and OPEX
estimates related to the mining and filtered-tailings placement activities. Scorpio Gold provided information
on the balance of project costs and general and administrative cost estimates. The economic highlights of
the project are presented in Table 1 below.
Scorpio Gold Corporation | 2
Table 1: Economic Highlights
Defined terms not otherwise defined herein shall have the meanings ascribed to them under the heading “Units of Measure” in this
news release.
Drilling
A total of 3,671 ft (1,119 m) of drilling in 34 sonic core drill holes was completed to test the grade of the
leach pad material. Sonic drill core was placed in plastic bags in nominal 2.5 ft (0.76 m) intervals at the
drill rig by the drillers and transferred to the Mineral Ridge assay laboratory on site after the completion of
each drill hole by Mineral Ridge, LLC (“Mineral Ridge”) geologists. At the Mineral Ridge assay laboratory,
the material from the sample bags was composited into 10 ft (3 m) intervals, dried, disaggrega ted, split to
250 g, and sent to Florin Analytical Services (“Florin”) in Reno for gold and silver assay. At Florin, the
entire sample was pulverized to 80% passing 75 microns, homogenized, and gold determined by one-assay
ton fire assay and AAS finish and silver determined by four-acid digestion and AAS finish.
Blanks, standards, and duplicates were inserted into the sample sequence by Mineral Ridge prior to sending
the samples to Florin for analysis to determine the quality of the Florin gold assays. Standards and blanks
indicate that Florin assays are acceptably accurate and there is no significant carryover contamination.
Duplicate pairs returned poor precision and screen fire assays indicate that coarse gold is likely a
contributing factor in the poor precision of the duplicate results. The 2017 Florin gold assay data ar e
sufficiently accurate and precise for use in mineral resource estimation.
Mineral Resources and Mineral Reserves
There has been no change to the mineral resource estimate as disclosed in the press release dated August
14, 2017.
The mineral resources are comprised of material contained entirely within the leach pad as of June 29, 2017.
While newly mined material from the available open -pit resource will continue to be placed on the heap
leach pad through October 2017, the material added in this time per iod is not included as it has not been
validated as part of the current mineral resource estimate.
It is assumed that as the leach pad is mined, there will be no selectivity of the material to be processed, and
therefore, the mineral resources presented represent a global estimate of the tonnage and grade.
Unit Total / Avg
Construction period y 1
Operating period y 4.7
Total pad material milled t 6,854,993
Average gold grade opt 0.0171
Recovery, after process and refine % 90.5%
Life of project gold sold k oz 106.0
Avg annual gold sold k oz/y 22.6
Realized gold price $/oz $ 1,249.50
Average silver grade opt 0.0169
Avg annual silver sold k oz/y 5.9
Total cash cost $/oz 716.54$
Initial capital expenditures M 34.9$
Total after-tax net cash flow M 25.4$
Salvage value, net M 4.5$
NPV of net cash flow
discounted at 5%
Payback from end of
construction 2.9 years
16.5$ million
IRR
9.4%
22.5%
IRR at $1,100 / oz gold
Scorpio Gold Corporation | 3
Ordinary Kriging was used for the gold resource estimation with Inverse Distance, Inverse Distance
Squared and Nearest Neighbor estimates serving as validation models. Silver estimates were run using a
single Inverse Distance model and a Nearest Neighbor estimate as a validation model.
For reasonable prospects of eventual economic extraction, the gold price used is the 3-year trailing average
gold price through June 2017. The process recovery is that obtained by Kappes, Cassiday & Associates
(“KCA”) test-work using reasonable mill -scenario. The processing cost was provided by M ineral Ridge
using actual Mineral Ridge Mine labor costs, and conceptual mill processing costs estimated by Novus for
a 4,000 tpd mill operation.
Table 2: Mineral Ridge Mineral Resource Statement
Mineral Resource Classification Tons
(kt)
Au
(opt)
Ag
(opt)
Contained
Au (koz)
Contained
Ag (koz)
Measured 2,895 0.017 0.016 48.5 46.4
Indicated 4,220 0.017 0.018 73.2 74.1
Measured & Indicated 7,115 0.017 0.017 121.7 120.4
Inferred 76 0.016 0.027 1.2 2.0
Notes:
1. The effective date of the Mineral Resource estimate is June 29, 2017.
2. The Qualified Person for the estimate is Mr Ian Crundwell, P.Geo.
3. Mineral Resources are quoted only for the Mineralized Leach Pad.
4. Mineral Resources are contained within the Mineral Ridge leach pad facility with the following assumptions:
a. A long-term gold price of US$1,216/oz.
b. Assumed process costs are US$11/t.
c. Metallurgical recovery for gold is 91%.
5. Rounding may result in apparent differences between when summing tons, grade and contained metal content.
6. Tonnage and grade measurements are in Imperial units. Grades are reported in opt.
7. The resource estimate was prepared with reference to CIM Definition Standards for Mineral Resources and Mineral
Reserves (2014) and CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (2003).
8. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
Conversion from Mineral Resources to Mineral Reserves is relatively straightforward. Given the nature of
the reclaimed material on the heap leach pad and the method of mining, the assumption is that all material
will be mined and processed, less any material left in place due to permit restrictions and facility location.
Allowance has been made for facility location which excludes 260,000 tons, which must remain in place,
according to the heap material mining and tailings placement design completed by Newfields.
Based on the criteria above, the Mineral Reserve Estimate is provided in Table 3 below. Given the positive
economic analysis of the Project, the mill feed material can in fact be considered a Mineral Reserve.
Table 3: Mineral Ridge Mineral Reserve Estimate
Mineral Reserve Classification Tons
(kt)
Au
(opt)
Ag
(opt)
Contained
Au (koz)
Contained
Ag (koz)
Proven 2,895 0.017 0.016 48.5 46.4
Probable 4,220 0.017 0.018 73.2 74.1
Less Material Remaining in Place (260) 0.017 0.017 (4.5) (4.6)
Total Proven & Probable 6,855 0.017 0.017 117.2 115.9
Notes:
1. Mineral Resources are contained within the Mineral Ridge leach pad facility with the following assumptions:
a. A long-term gold price of US$1,216/oz.
Scorpio Gold Corporation | 4
b. Assumed process costs are US$11/t.
c. Metallurgical recovery for gold is 91%.
2. Rounding may result in apparent differences between when summing tons, grade and contained metal content.
3. Tonnage and grade measurements are in Imperial units. Grades are reported in opt.
Mineral Processing
The proposed processing plant will be conventional and will re -process gold heap leach residual material
at a rate of 4,000 tpd with an equipment availability of 92% (365 d/a). The process flowsheet developed for
the Mineral Ridge heap leach residues is a combination of conventional comminution using ball-mills, and
CIL cyanidation to recover gold and silver. The process plant will produce a gold and silver loaded activated
carbon product from the CIL circuit. Based on the annual average throughput, and le aching and refinery
recoveries, the process plant is estimated to produce approximately 22,583 oz of gold and 5,886 oz of silver
from the mill feed grading 0.0171 opt gold and 0.0169 opt silver. The estimated gold and silver recoveries
in the CIL circuit a re 91% and 24% respectively. The loaded carbon will be shipped off -site to a refinery
to recover the gold and silver. Refinery recovery is estimated in 99.4%.
The process plant will consist of:
• Reclaiming area including mixing and holding tanks
• Grinding circuit consisting of two parallel ball mills
• A Pre-leach thickener
• Carbon in leach cyanidation
• Tailings thickening and filtration
The process flowsheet was developed based on parameters established from test work conducted by KCA
mainly from 2014 to 201 7, as well as Novus ’ engineering experience. The size selection of the grinding
mills was based on the amenability of the reclaimed ore to grinding determined through test programs
performed by laboratories. The CIL tank sizing was based on leaching times determined by test work and
using scale-up factors and experience.
Test programs evaluated several options for treating the reclaimed Mineral Ridge heap leach material.
Samples showed regular to poor responses to conventional flotation. The CIL process w as chosen as the
best available alternative due to higher gold recoveries. As part of the study, several areas for optimization
and simplification were identified in the process plant design, which reduced operational and capital
requirements.
The major criteria used in the plant design to process 4,000 tpd equivalent to 1,460,000 tpa is outlined in
Table 4.
Table 4: Major Design Criteria
Criteria Unit Value
Daily Processing Rate tpd 4,000
Operating Days per Year d/a 365
Operating Schedule - two shifts/day; 12 hours/shift
Mill Feed Grade – Average opt 0.0171
Metal Recovery - CIL % Au 91
Metal Recovery - CIL % Ag 24
Refining Recovery - Au & Ag % 99.4
Reclaimed Ore Particle Size, 80% passing in 0.14
Grinding / CIL Availability % 92
Scorpio Gold Corporation | 5
Criteria Unit Value
Milling and CIL Process Rate tph 181.2
Ball Mill Grinding Particle Size, 80% passing mesh 200
Ball Mill Circulating Load % 300
Bond Ball Mill Work Index kWh/t 15.3
CIL slurry feed density % 45
CIL residence time h 36
Final tailings cake moisture % 15
The grinding plant will receive material from the previous heap leaching operation. This material will be
reclaimed, scalped to remove trash, and mixed with water to form slurry of approximately 55% solids. The
slurry will then be transferred to a holding tank and pumped to the ball mill pump box. The design
contemplates two ball mills operating in parallel, with a shared pump box for both mills and dedicated
cyclone clusters for each ball mill. The cyclone overflow has a design 80% passing size of 200 mesh (74
microns) and feeds a pre-leach linear trash screen. The cyclone underflow will return to the two ball mills.
The mills are designed to process 2,000 tpd each. The linear trash screen undersize reports by gravity to the
pre-leach high-rate thickener where the slurry is flocculated and thickened to a density of 60% solids. The
thickener overflow is recycled to the process water pond for reuse and the thickener underflow reports to
the leaching circuit.
The leaching circuit will consist of four tanks ope rating in series with a total residence time of 36 hours.
The slurry density will be adjusted by recycling the overflow from the tailings thickener for the CIL circuit
to operate at 45% solids. It is expected that the slurry will arrive at the CIL circuit at a pH of 10.5;
adjustments will be made to maintain the required pH level, as necessary. Slurry will flow by gravity to
each tank. Dissolved gold and silver in the slurry will be adsorbed onto activated carbon and discharged
from the circuit at a designe d rate of two tons per day. Every 14 days bagged loaded carbon will be
transported to an external facility for final gold and silver recovery, and carbon regeneration and recycling.
The current operation at Mineral Ridge is a heap-leach operation, which uses reactivated carbon to adsorb
gold from the pregnant leach solution. The existing carbon handling infrastructure, which includes carbon
receiving, attritioning, sizing, sampling, and loading is suitable for the new process.
The CIL tailings will pass through a carbon safety screen to capture fugitive loaded carbon, and will report
to a tailings thickener for cyanide solution recovery. The tailings thickener overflow will be recycled to the
leach feed while the underflow will be sent to the tailings filters, where additional cyanide solution will be
recovered. The filter cake at a designed moisture of 15% will be transported by existing grasshopper
conveyors to the tailings pad. The tailings filter cake will be placed on the lined heap leach pad.
Infrastructure
The existing site infrastructure at the Mineral Ridge property is in good repair and is deemed suitable to
support the envisioned operations in the feasibility study. The following items were reviewed and found
suitable for use for the project.
Substation and power distribution: additional distribution costs were considered in the CAPEX estimate.
The main substation was found suitable to support ongoing activities.
• Maintenance facilities: no expansion necessary.
• Fuel storage: suitable as is.
• Roads: suitable as is.
• Water Supply and Management: suitable as is.
• Assay Lab: suitable as is.
• Offices: suitable as is.
Scorpio Gold Corporation | 6
• Lined pad for tailings storage: expansion required and included in the CAPEX estimate.
• Carbon handling facility: suitable as is.
Economic Analysis
The economic viability of the project has been evaluated using constant dollar, unleveraged (no financing),
after-tax discounted cash flow (DCF) methodology. This valuation method requires projecting material
balances estimated from operations and calculating resulting economics. Economic value is calculated from
sales of metal plus net equipment salvage value and bond collateral less cash outflows such as operating
costs, management fees, capital costs, working capital changes, any applicable taxes and reclamation costs.
Resulting annual cash flows are used to calculate the net present value (NPV) and internal rate of return
(IRR) of the project.
The NPV 5 is $16.5 million and the IRR is 22.5%, with payback 2.9 year s from the end of cons truction.
The project’s economic metrics are most sensitive to changes in grade and metals price, and less sensitive
to changes in operating and capital costs.
Permitting and duration of construction timetables are such that first production is scheduled to commence
start of third quarter 2019. Table 5 sets for the production schedule, grades and recoveries that result in
salable metal.
Table 5: Production Schedule
Gold prices for all project years are forecast at $1,250/oz, less $0.50/oz. of gold per contract with buyer.
Forecast silver prices are from a June 30, 2017 CIBC Global Mining Group, Analyst Consensus Commodity
Price Forecasts study, less $0.01/oz. of silver per contract wit h buyer. The price of silver varies year over
year between $19.28/oz to $19.82/oz, with an average price over the project life of $19.76/oz. Table 6
shows ounces of metal for sale, prices and resulting revenues. Given the terms of the selling agreement
(payment five days following placement for sale) and production inventory time due to shipping from the
mill to the stripper and then to the refinery (stripping time is 16 days and refining 7 days, inclusive of
transport time), receipt of payment for revenues is delayed by 28 days. The cash impact of these timing
differences is noted in the last two lines of Table 6 and, combined with accounts payable changes is noted
as working capital in Table 9: Cash Flow.
Scorpio Gold Corporation | 7
Table 6: Salable Ounces, Price and Revenue and Working Capital Changes
Operating costs are summarized in Table 7.
Table 7: Operating Costs
Capital costs, reclamation bond collateral, reclamation costs and recovery of bond collateral are
summarized in Table 8.
Table 8: Capital, Bond and Reclamation Costs
Scorpio Gold Corporation | 8
Table 9: Cash Flow
Figure 1: Cash Flow Chart