Sunshine Mine

Sunshine Mine

Low Risk

Mining-friendly jurisdiction with low political risk, existing infrastructure and strong community support

High Grade

One of the highest-grade large primary silver deposits in the world with an average measured and indicated resource grade of 786 g/t

Near Term

The project has all environmental permits and the mine can be recommissioned within two years after securing funding

Under-explored

75 million measured and indicated and 221 million inferred ounces of silver resources with unexplored veins and vein extensions

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Overview

The Sunshine Mine is a brand… as well as the iconic jewel of American silver mining. From the highest grade, large primary silver mine in the world’s safest jurisdiction to an end-product refinery that will produce silver bars certified for direct delivery to COMEX, the Sunshine complex is slated to be the only completely autonomous and fully integrated silver mining operation in the United States.

This former prolific producing mine has all the environmental permits to resume mining, concentrate production and, with the 2013 acquisition of the Sunshine Refinery, refining of COMEX certified silver bullion and copper.

The Sunshine Mine is in the Coeur d’ Alene mining district of northern Idaho, which was the largest silver producing region in the United States. It has existing interstate highway access, power, water and access to an experienced work force. This mine has a long history, dating back to 1884 when the Blake Brothers, Dennis and True, arrived from Maine and staked the Yankee Lode mining claim on the east slope of Big Creek. They mined the claim for the next two decades. Throughout the ensuing years various owners mined the claim, and in 1935 a ball mill and concentrator were constructed, followed by the sinking of the Jewell Shaft in 1936. The mine operated under the management of Sunshine Mining Company from 1918 until 2001, when the mine ceased production due to low silver prices and other factors.

The mine was briefly restarted in 2007 by Sterling Mining Company and operated until 2009, when it again ceased production. The mine was subsequently purchased by Silver Opportunity Partners, a subsidiary of the investment fund Electrum Ltd., in 2010 and was combined into Sunshine Silver Mining & Refining Corporation.

Additional exploration drilling from 2011 through 2013 resulted in significant new discovery of mineralized veins that increased the measured, indicated and inferred resources at the mine.

Highlights from an NI 43-101 compliant 2014 Preliminary Economic Assessment (PEA) include:

  • A 24-year mine-life processing 1,200 tons per day at 24.8 ounces per ton (850g/t) average silver grade,
  • Average annual production of 9.4 million silver ounces,
  • $75 million free cash flow annually after commissioning investment,
  • All-in sustaining production costs of $11.86 per ounce silver on a bi-product basis.

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Geology & Mineralogy

Over 30 veins have been named and mined at the Sunshine Mine throughout its history; the Sunshine and Chester Veins have each produced over 90 million ounces of silver. The majority of veins strike east-west and dip to the south. Locally, dips range from 45° to 90°. Strike lengths locally exceed 2,000 feet and dip lengths are two to three times greater than the strike length. Major veins are located between the faults at an angle of 25° to the bounding faults. Veins vary in width from a few inches to over 30 feet, but are typically between one to five feet thick. Ore minerals include tetrahedrite and galena, with siderite and quartz as the principal gangue minerals. Accessory minerals include bournonite, pyrargyrite, and magnetite.

The combination of faults, folds, fractures, and favorable host rocks created suitable conditions for mineral emplacement by silver-rich base metal veins. Historically, underground drilling and drifting were the most productive exploration tools.

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Exploration

Using modern technology to systematically explore a world-class deposit in the United States most prolific silver district

Since acquiring the Sunshine Mine, Sunshine Silver has achieved outstanding resource discovery success through an exploration program that targeted prospective areas in the shallower portions of the deposit. This resulted in the discovery of two previously unknown vein systems and two extensions of known vein systems.  We believe that the newly discovered mineralized veins exist because this is near the deposit discovery outcrop that was initially mined over a century ago.  Modern exploration techniques did not exist and miners used simple manual methods; just following veins until they disappeared or became uneconomic.  The upper portions of the deposit have never been subjected to systematic exploration drilling.

The exploration to-date has validated our theory and has been instrumental in our strategy to redevelop the Sunshine deposit.  It will allow Sunshine Silver to reactivate the mine with less initial development because access to this area already exists through a surface portal called the Sterling Tunnel (See figure below).  Most importantly, Sunshine Silver will be developing and mining new mineralized veins and not conducting remnant mining.  We view the Sunshine Mine as a new deposit to be explored and mined with efficient techniques using modern equipment.

Recent Drilling

Recent exploration results at the Sunshine Mine have focused on newly-discovered extensions of the South Yankee Boy Split Vein, Sunshine Vein extension, 10 Vein discovery and West Chance Link Vein extension. All exist in the shallower portions of the deposit, which is readily accessible.

Sunshine Mine Cross Section

South Yankee Boy Spit Vein Discovery
South Yankee Boy Split
DDH ID Intercept Length (m) Ag (g/t) Cu (%) Pb (%)
ST-2651 0.09 555 0.24 0.05
ST-2653 0.67 1234 0.98 0.20
ST-2655 0.73 562 2.20 0.05
ST-2658 1.22 709 0.78 0.41
ST-2659 0.58 708 0.4 0.05
ST-2662 0.67 1575 1.02 0.90
Average 0.66 891 0.94 0.28
Sunshine Vein Extension
Sunshine Vein Extension
DDH ID Intercept Length (m) Ag (g/t) Cu (%) Pb (%)
ST-2625 1.16 1246 0.41 0.13
ST-2627 0.52 520 0.24 0.05
ST-2628 0.55 2142 1.54 0.05
ST-2629 0.79 5799 1.83 0.07
ST-2630 0.09 3703 1.81 0.05
ST-2631 0.15 2191 1.00 0.16
ST-2632 0.64 415 0.15 0.05
ST-2636 0.4 321 0.06 3.34
ST-2637 0.61 2126 1.49 0.12
ST-2638 0.15 1114 0.63 0.05
ST-2640 0.18 1025 0.33 0.00
ST-2641 1.43 3615 0.82 0.05
ST-2644 0.37 1087 0.51 0.05
ST-2645 0.46 765 0.36 0.05
ST-2646 0.18 672 0.25 0.00
ST-2648 1.22 480 0.15 0.16
ST-2653 0.27 624 0.44 0.05
ST-2654 0.49 946 0.28 0.05
ST-2655 0.52 435 0.13 0.00
ST-2656 0.09 1797 0.69 0.00
ST-2658 0.85 829 0.21 0.08
ST-2659 0.88 3044 0.70 0.09
ST-2661 0.37 477 0.16 0.17
ST-2662 0.40 2901 1.11 0.2
ST-2664 0.46 511 0.21 0.05
ST-2665 1.1 634 0.24 0.05
Average 0.55 1516 0.61 0.20
10 Vein Discovery
10 Vein
DDH ID Intercept Length (m) Ag (g/t) Cu (%) Pb (%)
ST-2625 1.58 250 0.54 10.59
ST-2627 0.18 208 0.04 11.10
ST-2628 1.31 1063 0.47 12.80
ST-2631 1.13 1234 0.10 57.40
ST-2632 1.55 1824 0.71 15.89
ST-2635 1.37 477 0.13 13.60
ST-2636 0.46 473 0.07 14.20
ST-2637 0.40 337 0.05 14.4
ST-2638 0.67 340 0.09 9.90
ST-2644 0.37 483 0.08 20.27
Average 0.90 669 0.23 18.01

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Resources

The Company completed an updated 43-101 compliant Preliminary Economic Analysis in March 2014. The resources estimated in that report are as follows.

Sunshine Mine Resource Estimate, 2014
Resource Class Tons Diluted Ag Grade – Diluted (g/t) Ag Contained Ounces Cu % Pb % Zn %
Measured 1,120,000 843 30,300,000
Indicated 1,870,000 752 45,200,000
Measured & Indicated 2,980,000 786 75,500,000
Inferred 8,170,000 842 221,300,000 0.22 0.35 0.02

Source: NI43-101 Technical Report, Tetratech, 2014

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Sunshine Refinery

The Sunshine Precious Metals Refinery is now owned by Sunshine Silver Mining & Refining Corporation.

Sunshine Refinery Logo

Located in the world famous Silver Valley of the Coeur d’Alene mining district in northern Idaho, the Sunshine Precious Metals Refinery was originally constructed for exclusive processing of concentrates from the Sunshine Mine. Sunshine Silver is excited to have reacquired the refinery and re-establish the Sunshine Mine as a vertically integrated project that explores, develops, mines and refines high quality silver bars for direct delivery to Comex.

The Sunshine Precious Metals Refinery has widely been recognized as among the best quality refiners, with consistent fineness of 999.5 silver or better and 999.5 gold or better. Utilizing state-of-the-art processes and equipment the refining facility will process copper/silver and gold concentrates in addition to refining silver doré and other materials. The Sunshine Silver brand is certified for good delivery on the COMEX.

Sunshine Refinery Exterior

Originally constructed by the Sunshine Mining & Refining Company (unrelated to Sunshine Silver) in 1942 to process marketable antimony product from the Sunshine Mine, the refinery was expanded in 1984 to further process copper/silver concentrates to deliverable silver bullion.

The Sunshine Refinery is currently not in operation and is anticipated to recommence production when the Sunshine Mine is again producing concentrates from the Mine.

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PEA

The Sunshine Mine Preliminary Economic Analysis, completed by MTB in 2014, shows the highly economic mine life and production capability of the mine, at modeled metals’ prices.

Highlights

Mine Life 24 Years
Full Production Mining Rate 1,200 tons per day
Silver Grade 24.8 oz/ton (850 g/t)
Silver Recovery 92% in Upper, 96% in Lower
Silver Production (peak) 10 to 12 million ounces
Average Annual Production (LOM) 9.4 million ounces
Cash Cost $9.16/Ag oz.
All-In Sustaining Cost $11.86/Ag oz.
NPV5% $570 million
Payback Period 6 years

Note: Economic calculations performed at the following long-term metals prices: $21.26/oz Ag, $3.00/lb Cu, $0.96/lb Pb, $5.00/lb Sb. See PEA for years 1-4 pricing.

Mine Plan

Total diluted and recovered ore tonnes (LOM) 9,483,785
LOM Silver Concentrate(tons) 129,928
LOM Lead Concentrate(tons) 204,850

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Technical Reports

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Image Gallery

Phone: 303-784-5350
E-mail Us

1660 Lincoln Street, Suite 2750

Denver, CO 80264

Copyright © 2017 Sunshine Silver Mining & Refining Corporation. All Rights Reserved.