Golden Minerals Company
 
   
 
  
Exploration Properties
   

Golden Minerals controls a diversified portfolio of approximately 10 precious metals and other mineral exploration properties located primarily in or near historic precious metals producing regions of Mexico.


Santa Maria

Overview

We hold the right to acquire the Santa Maria property under two separate option agreements, with additional payments of approximately $1.2 million (as of July 2018) payable through April 2022.

Since 2015, we have completed several drill programs as well as test mining and processing of 7,500 tons from the Santa Maria mine, with realized average grades 338 gpt silver and 0.7 gpt gold.

We have reported two Preliminary Economic Assessments ("PEA") at Santa Maria, both completed by independent engineering firm Tetra Tech and prepared pursuant to Canadian National Instrument 43-101. The first PEA, reported in March 2017, presented an assessment of developing Santa Maria's mineral deposit via a 38-month underground mining operation at a mining rate of 200 tonnes per day, using a combination of cut and fill and other mining techniques, and custom milling at a local third-party flotation mill.

In August 2017, we began a new drill program targeting extensions of the vein deposit described in the 2017 PEA and resource estimate, with the goal of expanding the existing estimate of mineralized material to improve the project's overall economics. We released final results from this 22-hole, 4,800-meter drill program in April 2018.

In October 2018, we reported improved project economics in a second PEA and accompanying 43-101 resource estimate, both completed by Tetra Tech. The new PEA shows significant improvements in projected profitability, metal production and cash flow compared to the 2017 PEA, with estimated future cash flow and NPV increasing by around 50%. Projected mine life has lengthened to 4.2 years with an average production rate of around 220 tonnes per day.

2015 – Test Mining

During the third quarter 2015 we mined approximately 3,000 tonnes of material from the vein as bulk samples at a total cost of about $0.25 million and entered into a contract to process the material for metallurgical and process testing purposes at a local third-party toll milling facility at a cost of about $0.1 million. The extracted material, mined from a high grade portion of the vein, had grades of approximately 500 gpt silver and 0.9 gpt gold. We did not have sufficient drilling data to predict the ultimate size of this higher grade zone. The 3,000 tonnes of mined material processed through the toll milling facility generated approximately 113 tonnes of concentrates containing approximately 47,000 ounces of silver and 80 ounces of gold. Under an October 2015 sales agreement, we received proceeds for approximately 32,000 ounces of silver and 45 ounces of gold with a net payable value of about $0.4 million. As required by the option agreement, we used a portion of the proceeds from the sale of the concentrates to pay the claim owner an advance royalty payment of $0.2 million, credited toward the $1.2 million purchase price of the property, with the remaining proceeds used to reimburse our costs for exploration and mining activities at Santa Maria since April 2015.

2016 –Additional Test Mining

During the first two quarters of 2016 we mined approximately 4,500 tonnes of material as a bulk sample with grades of approximately 235 gpt silver and 0.7 gpt gold. This material was substantially lower in grade than material mined in 2015 from the same vein. We processed the bulk sample through a toll milling facility, generating approximately 100 tonnes of concentrates containing approximately 22,000 ounces of silver and 44 ounces of gold. The concentrates were sold to a third party for approximately $0.3 million during the first two quarters of 2016 consisting of approximately 21,000 payable ounces of silver and 40 payable ounces of gold, which offset exploration costs. The average grade of 7,500 tons mined and processed in bulk samples since 2015 is 338 gpt silver and 0.7 gpt gold.

Q1 2017 – Preliminary Economic Assessment and NI 43-101

In March 2017 a PEA was completed on our behalf by the engineering firm of Tetra Tech, based on an updated estimate of mineralized material. The PEA presents a base case assessment of developing Santa Maria's mineral deposit. The PEA contemplates a 34-month underground mining operation at a mining rate of 200 tonnes per day using a combination of cut and fill and other mining techniques, and custom milling at a local third-party flotation mill. Based on the assumptions in the PEA, we believe there is potential to develop a small mining operation at Santa Maria.

PEA highlights include:

  • Post-tax net present value ("NPV") of $6.3 million and pre-tax internal rate of return of 84 percent at an 8 percent discount rate
  • Total capital requirements of $1.2 million (initial capital $1.0 million, sustaining capital $0.2 million)
  • Pre-production development time 10 to 11 months
  • Life of mine ("LOM") 2.8 years
  • Payback in month 16
  • LOM free cash flow $8.2 million
  • LOM silver production 2.0 Moz; LOM gold production 6.8 koz
  • LOM average silver grade 332 grams per tonne ("gpt"); average gold grade 1.28 gpt

Note: PEA parameters assume prices of $1,222/oz gold, $17.30/oz silver and a discount rate of eight percent. Values above are approximate. All $ values in $US.

In conjunction with the PEA, Tetra Tech completed an updated National Instrument 43-101 compliant mineral resource estimate at Santa Maria dated March 30, 2017. Details are as follows:

Classification Cutoff Grade Tonnes Ag g/t Au g/t Ag toz (M) Au toz (k) AgEq toz (M) Dilution %
Recovered AgEq g/t
Indicated 175 180,000 304 1.4 1.73 8.1 2.31 10%
Inferred 175 120,000 343 1.0 1.37 3.9 1.64 19%

Notes:
1  Mineral resources are reported as diluted Tonnes and grade;
2  Cutoff grade and Ag equivalent calculated using metal prices of $17.30 and $1,222 per troy ounce
    of Ag and Au with a ratio of 70.6:1, the three year trailing average as of the end of December 2016;
3  Cutoff applied to diluted Ag equivalent blocks grades using recoveries of 90% and 80% Ag and Au;
4  Reported indicated mineral resources are equivalent to mineralized material under SEC Industry Guide 7,
    inferred mineral resource is not a recognized category under SEC Industry Guide 7; and
5  Columns may not total due to rounding.

Q3 2017 – Additional Claims Purchased and New Drill Program Begun

In August 2017, Golden acquired three additional claims totaling approximately 77 hectares on strike and downdip along the Santa Maria vein system. The new claims provide a 600-meter potential extension to the strike length of the vein system and add substantial downdip expansion potential. Surface exposures of the vein on the new claims have yielded values of silver and gold over potentially minable widths of a magnitude similar to the existing resource grade.

The 2017 drill program was initiated by the Company with the goal of expanding the existing resource to improve the overall economics reported in the Preliminary Economic Assessment ("PEA") published in March 2017.

In April 2018, we released final results from the 22-hole, 4,800-meter drill program. The recent drilling encountered oxidized vein material to much greater depths in the eastern part of the Santa Maria vein system than in the western part. The oxidized portion of the eastern vein system is preserved due to normal faulting and post-mineral basalt cover. In addition to the previously known Santa Maria vein and the hanging wall vein, Santa Maria 2, a breccia vein labelled NE breccia was encountered in some of the drill holes (see table of results). Metallurgical test-work on the oxide material is yet to be completed. The Company plans to update the resource model and the PEA based on the new drill results and the new metallurgical studies once those are available.

Q3 2018 - Second PEA and Resource Estimate

A second PEA for Santa Maria was completed for Golden Minerals by Tetra Tech in September 2018. This second PEA shows improvement in numerous project metrics as compared to the initial PEA completed in March 2017. A new resource estimate accompanies the 2018 PEA.

PEA HIGHLIGHTS

  • After-tax NPV: (US)$10.6 million at a 5% discount rate
  • After-tax IRR: 159.0%
  • After-tax payback period: 10 months
  • Total capital cost: $1.2 million, comprised of $1.0 million initial and $0.2 million sustaining capital expenditures
  • Pre-production development time: 6 months
  • Life of mine (LOM): 4.2 years
  • LOM after tax free cash flow $12.4 million
  • LOM payable silver production 2.66 million oz.
  • LOM payable silver equivalent production 3.13 million oz1
  • LOM average silver grade 331 grams per tonne ("g/t")
  • LOM average gold grade 0.78 g/t
  • Net cash cost $10.72 per payable ounce of silver2
  • All-in sustaining costs ("AISC") $11.12 per payable silver oz.2

1 Calculated using prices of Au $1,238/oz and Ag $16.63/oz, or 74:1 gold: silver
2 Cash cost and AISC are defined in "Non-GAAP Financial Measures" below

Note: PEA parameters assume a silver price of $16.63/oz and a gold price of $1,238/oz, which are the three-year trailing average prices, per SEC reporting guidelines, and a discount rate of 5%.

Classification Cutoff Grade Tonnes Ag g/t Au g/t AgEq g/t Ag toz Au toz AgEq toz
AgEq g/t (M) (k) (M)
Measured 180 42,000 271 0.83 333 0.37 1.13 0.45
Indicated 180 170,000 291 1.04 368 1.59 5.7 2.01
Inferred 180 261,000 272 0.9 346 2.3 7.61 2.92

Notes:

  1. Cutoff grade and Ag equivalent calculated using metal prices of $16.63 and $1,238 per troy ounce of Ag and Au with a ratio of 74:1, the 3-year trailing average as of the end of May 2018;
  2. Cutoff applied to diluted Ag equivalent block grades using recoveries of 90% and 80% Ag and Au; 3. Columns may not total due to rounding.

Santa Maria: 2014 – 2018 Drilling Program Results

     
Santa Maria
Complete Drill
Hole Results,
May 2018
     

2017-2018 Surface Sample Assay Results

Santa Maria Surface Samples - Gold Santa Maria Surface Samples - Lead Santa Maria Surface Samples - Silver Santa Maria Surface Samples - Zinc

Santa Maria: 2016 Drilling Program

El Quevare Conceptual Plan    
Santa Maria
Drilling Plan View
Santa Maria Long Section August 2016    

Santa Maria Q3 2017 Drilling Program

 
Overview Current Drill Program Potential Vein Expansion  

 


Rodeo

Rodeo is a 1,900-hectare gold project located in Durango State, Mexico approximately 80 kilometers west of the Company's Velardeña properties and processing mills. Golden acquired the Rodeo property subject to a royalty interest due to La Cuesta International in the second quarter 2015, prior to which exploration by other companies identified a gold-bearing system exposed at surface.

Golden conducted a 2,080-meter core drilling program at Rodeo in 2016. Partial results from the first round of drilling, released in September 2016, show a gold and silver bearing epithermal vein and breccia system with encouraging gold and silver values over an approximate 50 to 70 meter true width. The system is exposed at the top of a northwesterly striking ridge and dips steeply to the northeast. This could provide the possibility of open pit mining if we discover a deposit with sufficient tonnage of an appropriate grade and other characteristics to justify mining. The drill holes reported previously are spaced about 25 meters apart along 100 meters of the crest of the mineralized ridge. The drill holes are angle holes oriented at 55° to the southwest and cut the vein and breccia system at an angle of approximately 50°. Previous work has shown the mineralized system to be exposed at surface over about one kilometer of strike length.

We completed the drill program in Q4 2016 and announced a Canadian National Instrument 43-101 compliant mineral resource estimate in January 2017. Below are two resource estimates based on two processing scenarios and their respective cutoff grades and open-pit optimization models. Table 1 presents a mill grade resource that may be processed in the Company's existing oxide mill at Velardeña. This case provides a potentially shorter time to production and lower capital costs, since the Company owns the production mill located within trucking distance of the Rodeo property. Table 2 presents a heap leach case that could be a standalone operation, depending on leachability and costs of the standalone heap leach operation.

Rodeo: Base Case (Mill Processing)      
  Tonnes
M
Silver
M oz
Gold
'000 oz
Gold Eq.
'000 oz
  Silver
g/t
Gold
g/t
Indicated 0.4 0.2 46 47.8   11 3.3
Inferred - - - -   - -

Notes:
1  Cutoff grade and Au equivalent calculated using metal prices of $1,220 and $17 per troy ounce of Au and Ag,
    recoveries of 77% and 90% Au and Ag;
2  Mineral resources have been pit shell constrained using the Lerch Grossman algorithm with cost inputs
    per tonne of $7.50 mining, $10 trucking, and $20 processing. A breakeven cutoff including trucking and
    processing costs per block was applied to a block model within the optimized shell;
3  Metal prices do not exceed three-year trailing average as of the end of December 2016, per SEC guidance;
4  Reported indicated mineral resources are equivalent to mineralized material under SEC Industry Guide 7, and
5  Au equivalent calculated at the ratio 72 Ag : 1 Au.

Exploration and metallurgical work is anticipated to continue at Rodeo. If our exploration efforts are successful, material from this property could be trucked to the Velardeña oxide plant for processing after the third party lease has terminated. La Cuesta holds a 2% net smelter return royalty on production from the claims up to a total payable amount of $5.0 million. Our agreement requires a minimum program of 1,000 meters of drilling before May 2017.

 


Yoquivo

Yoquivo Surface Samples – October 2018

 
 
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