VANCOUVER, BRITISH COLUMBIA--(Marketwired - Dec 12, 2014) - Global Minerals Ltd. (TSX VENTURE:CTG)(DFPM.F) ("Global" or the "Company") is pleased to announce the results of a positive Preliminary Economic Assessment ("PEA") for its 100%-owned Strieborná silver-copper-antimony deposit in Slovakia ("Strieborná" or the "Project").
The PEA envisions an underground mine and conventional flotation milling operation with an initial seven year mine life. Mining output is modeled at 300 tonnes per day ("tpd") for the first two years, increasing to 500 tpd starting from year three. Over the life of mine ("LOM"), the Project is estimated to produce an annual average of 1.4 million silver ounces and 4.1 million pounds of copper. Cash cost per ounce of silver, after copper by-product credits, is $10.82 per ounce.
PEA Highlights (all amounts in US dollars unless otherwise indicated)
- Base Case is stated assuming $20/oz silver and $3.00/lb copper as long term metal prices.
- Pre-tax NPV (5%) of $11 million, IRR of 12.4%, and payback of 4.7 years.
- Post-tax NPV (5%) of $5 million, IRR of 8.3% and payback of 5.1 years.
- Pre-development capital costs of approximately $25.3 million, including contingency.
- Average silver cash costs (net of by-product sales) of $10.82/oz silver (see Non-U.S. GAAP Performance Measurement below).
- Post-tax LOM free cashflow generated is approximately $14.9 million.
- Average annual production in the initial 5 years is 1.4 million ounces of silver and 4.3 million pounds of copper.
- The study contemplates mining 983,000 tonnes of mineral at average grades of 307 gpt Ag and 1.3% Cu.
- LOM production of 9.5 million silver ounces and 28 million pounds of copper.
- LOM average silver and copper recovery in concentrate of 98%.
- Silver-copper concentrate with average grades of 6,570 gpt silver and 27.8% copper
The following table summarizes the main economic outputs of the discounted cash flow.
Table 1. Summary of Strieborná PEA key financial outputs
|NPV (0%)||$ Million||-1||23||47||-4||15||34|
|NPV (5%)||$ Million||-7||11||29||-10||5||19|
|LOM Metal Revenue (after fuming smelting, refining, payable royalties)||$ Million||148||172||196||148||172||196|
The Base Case discounted cash flows in the PEA are shown as both pre-tax and post-tax, and are prepared in compliance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") of the Canadian Securities Administrators. The PEA was completed by AGP Mining Consultants ("AGP"), an independent Canadian-based engineering firm. Unless otherwise noted, a reference to "$" in this news release is to United States currency. Due to rounding, some of the totals in the tables in this news release may not sum exactly.
The PEA is preliminary in nature and 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, and there is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
Tim McCutcheon, CEO, commented; "This Preliminary Economic Assessment on Strieborná is the culmination of much work completed by the Global team and its advisors. The results clearly illustrate the potential of our 100% owned, reduced execution risk, silver-copper deposit. The PEA will assist us in advancing the Project towards development, while giving us the flexibility to consider various options.
"Strieborná has the key advantage of being an unexploited deposit which lies within an existing mining complex. As such, key issues which would normally add cost and risk to a project at this stage, such as power availability and infrastructure access, are largely resolved. The pre-production capital cost of $25 million well reflects this concept and puts Strieborná in a small peer group of "doable" projects for a Company of our size at a time when access to capital for mining is difficult. Despite the modest start-up capital, there is significant room for Project enhancement, which include recovering antimony as a payable metal, moving down the value-added chain from concentrate, and expanding the resource. These opportunities can be best addressed at a time of established commercial production.
"Management's philosophy is to get Strieborná up and running as soon and as cost efficiently as possible, and then seek ways to improve financial performance after the Company has cut its teeth on transitioning from developer to producer. The Company plans to use the existing infrastructure in place at the Strieborná mining complex as much as possible, and the development plan is to start off with simple concentrate production. As such, the lead time to go from PEA to feasibility to financing and operations should be very short. Equipment needed is readily available and not particularly complicated. Importantly, Strieborná already has a mining permit, and with that major milestone already achieved, the Project is significantly de-risked. Slovakia as a mining jurisdiction is very solid, with a government track record of encouraging industry and the stability of being both an EU and Eurozone member.
"The Project is anticipated, as per the PEA, to have an average annual silver equivalent production footprint of 1.4 million ounces. This puts Global squarely in a peer group of publically-listed companies that produce between 1.0 and 2.0 million ounces of silver, all of which are closely followed by silver mining investors who generally have limited options to invest in silver equities. We look forward to joining the ranks of public silver producing companies."
The PEA mining schedule envisions a 300 tpd operation for the first two years of operation, as such a level of operation is within the upper limit of the Company's current mining permit. Management believes that by the start of year three the Company will be able to increase the mining permit level to 500 tpd, which was historically the maximum output of the mine complex when it was in operation prior to Global's ownership. The increase in mining tonnage is achieved by adding extra work days and shifts to the mine work schedule. The mining method is mechanized with ramp access using sub-level stoping. This method was chosen as it maximized the use of existing infrastructure in place while creating efficiencies to lower operating cost. Material will be mined by crews using single boom jumbos and other mobile extraction equipment and hauled with 15 tonne compact profile underground trucks. These trucks will then haul material up a spiral incline ramp to the existing haulage tunnel and then dump their loads aboveground at a crush-grind-float plant facility to make a concentrate product.
The mine plan contains 979,000 tonnes of Measured and Indicated material, or 99.6% of the total plant feed. The remaining 4,000 tonnes of material in the plant feed is classified as Inferred. The high ratio of Measured and Indicated to Inferred material in the process feed emphasizes the high quality of the resource base used for the PEA and limits the amount of additional drilling that may be required prior to proceeding to a Feasibility Study.
Processing and Metallurgy
The proposed process plant is sized at 500 tpd of mill feed and will consist of conventional unit operations including crushing, grinding, rougher flotation, cleaner flotation, concentrate filtration, and tailings thickening.
Grinding and flotation testing was completed in 2011, 2013 and 2014 on samples of drill core and bulk samples at SGS in Cornwall, United Kingdom and at Blue Coast Research in BC, Canada, all under the supervision of Blue Coast Metallurgy. The most recent work done was performed on four separate composites collected on Strieborná level six from the bulk, channel and panel sampling program begun in 2Q2014 and completed in 3Q2014. The material tested was selected due to its expected similarity to material targeted for initial mining at the Project.
Grindability studies revealed the material to be consistently soft, with a low Bond Ball Mill Work Index of 8.7 kilowatt-hours per tonne. Key locked cycle and bulk flotation results show mean recoveries of 98% for both silver and copper. Locked cycle flotation testing has demonstrated that a simple flotation flow sheet with moderate grinds (145 micrometres) and two stages of cleaning is able to generate a high grade silver-copper concentrate, at very high recoveries. Toll treatment of the concentrate through an existing commercial facility removes the mercury and yields a saleable product.
The Project's focus mineral for concentration is tetrahedrite. Past test work has demonstrated the silver and copper content of tetrahedrite is fairly consistent and so the Project's concentrate product tends to have similar metals grades, while the key variable factor is mass pull, which is mostly a function of tetrahedrite content in mined material. Based on past flotation work, the PEA model assumes mill feed mass pull to concentrate is 4.73%. This yields a concentrate grade of 6,575 gpt silver and 27.8% copper with 98% recovery for both silver and copper.
Antimony is also prevalent in the Project's tetrahedrite. In the PEA concentrate assumptions, the antimony grade is 20.2%. Currently silver and copper are the payable metals while antimony in the concentrate is treated as a penalty. Testing to develop an on-site concentrate treatment scheme for antimony recovery has been progressing well, but more work remains to demonstrate its economic viability. As the Company has adopted a low risk strategy for the initial start-up, antimony recovery has not been adopted for the PEA but its planned development would offer substantial upside future potential for the Project.
Mercury grade in the PEA concentrate assumptions is 0.96%. Concentrate produced from Strieborná will be shipped to a recycling facility in Germany to fume mercury for its safe removal. The resultant product, called calcine, will then be sold onward to smelters for processing. The fuming process in test work has brought mercury levels down to 20 parts per million ("ppm"), which is below any threshold at which most smelters would levy penalties. The calcine product would have approximately 88% of the concentrate mass resulting in proportionately higher silver and copper grades in the product sent to smelters (Calcine grade is 7,500 gpt silver and 31.8% copper).
The pre-production capital cost estimate includes the underground mine capital, a 500 tpd processing plant, (grinding mill, flotation cells, thickeners) add-on infrastructure, environmental costs, owner's and indirect costs and contingency. The sustaining capital cost includes LOM replacement of mine and other equipment, infrastructure upgrades and reclamation costs. Initial capital and sustaining capital costs are summarized below in Table 2.
Table 2. Summary of Strieborná PEA capital cost estimates
|Capital Cost ($ Millions)|
|Owner's and Indirect Costs||3.2||0.9||0.2||4.3|
The Company is in the process of acquiring a nearby tailings facility (1.5 km from the Project site). The original contract between the Global and the tailing facility owners was for installment payments totaling EUR 2.5 million ($3.3 million), of which EUR 0.8 million ($1.0 million) has already been paid.
Management is working with the tailing facility owners to agree upon a time table to complete payments and take full title to the tailings facility.
Total LOM mine operating costs for the Project are expected to be $97.10/tonne of mill feed. LOM silver cash costs are $10.82/oz net of by-product (copper) credits. Any future recovery of antimony prior to concentrate shipment will likely result in a lower cash cost per ounce of silver. Table 3 below shows a sum of all operating cost categories on a cost per tonne of mill feed basis over the total tonnage.
Table 3. Summary of Strieborná PEA operating cost estimates
|$/dmt Ag-Cu |
|Mining (mill feed and waste)||59.37||1436.67|
|Subtotal On-Site Costs||92.02||2,226.89|
|Transportation, Port Costs, Shipping||5.08||122.95|
The PEA does not include any assumptions about capital structure, and management believes within the Slovakian tax code there are several opportunities to mitigate tax liabilities. Strieborná has been financed to date using intra-company loans and management intends to seek debt financing for a significant part of the capital cost to put Strieborná into operation.
PEA Mineral Resources
Global contracted Mine Development Associates ("MDA") based in Nevada, USA to prepare an updated mineral resource estimate for Strieborná.
The current resource estimate is based on approximately 6,043 metres of recent drilling in 40 holes and approximately 3,089 metres of historic drilling in 24 holes. The resource database also includes 1,094 historic channel samples, 25 historic panel samples, and recent channel and panel samples totaling 32 and 24, respectively. At the reported resource cutoff of 100 g/t Ag, the deposit is estimated to contain a Measured and Indicated mineral resource of 2,346,000 tonnes at 267 g/t Ag and 1.21% Cu and an Inferred mineral resource of 986,000 tonnes at 224 g/t Ag and 1.02% Cu. MDA also estimated antimony and iron as part of this study. At the reporting cutoff of 100 g/t Ag, the antimony grade is 0.85% and iron is 34.1% in the Measured and Indicated categories. MDA classifies resources in order of increasing geological and quantitative confidence into Inferred, Indicated, and Measured categories to be in compliance with the "CIM Definition Standards - For Mineral Resources and Mineral Reserves" (2014) and therefore Canadian National Instrument 43-101.
Table 4. Strieborná Constrained Mineral Resources
|Measured and Indicated|
|Ag, oz||Cu, |
|Ag, oz||Cu, |
Note: Steve Ristorcelli, C.P.G. is the Qualified Person under NI 43-101 responsible for this resource estimate.
Mineral resources that are not mineral reserves do not have demonstrated economic viability.
Although the mineral resources previously reported in November 2013 are not significantly different than the total mineralized inventory, which forms the basis of the current estimate, the geological data gathered in Global's new drift intersecting the vein on Level 6 was used for the updated estimate. The new data included panel and channel samples taken during 2Q2014 (see press release 7 July 2014). The resource update resulted in approximately a 2.4% increase in tonnes, Measured and Indicated categories at 100g/t Ag cutoff, at essentially the same grades in the previously reported estimate. Inferred tonnes were increased by 11.6% at 100g/t Ag cutoff using the new data.
The key estimation parameters used by MDA for the Strieborná estimate are as follows:
- Sample data was capped prior to compositing to two metres.
- MDA compared quantile plots of the grades and variograms of the different metals and noted that the silver, copper, and antimony occur together (probably in the same mineral tetrahedrite).
- All metals are contained within the veins and were therefore modeled as a single domain.
- Variograms of the capped grades composited to three metres were made for each metal in multiple directions.
- The block model is composed of blocks one-meter wide (across the vein), three-meters long (along strike), and four-meters high and using the inverse distance (4th) method to estimate the metal grades.
- MDA chose 3.55 g/cm3 for the density to assign to the Strieborná vein based on 152 measured densities. MDA used a calculated regression analysis formula to define the a density value from iron grades for the two other, and much less important, veins that had no density values.
- The resource was classified into Inferred or Measured and Indicated using a number of factors, taking into account confidence in the model, data spacing and various complementary geostatistical parameters.
- Estimation on the Strieborná vein was done in eight "zones" with varying dips and azimuths to better reflect the changing dips and azimuths of the vein. An octant search was used to de-cluster the composite data, and anisotropic weighting was used to give the estimate more defined plunge.
Near Term Development Plans
With the completion of a positive PEA study, Global now expects to advance to a feasibility level on the Project. This benchmark event will now allow the Company to target its three main near-term tasks; produce bulk concentrate samples to establish commercial-level smelter terms, continue engineering and geological work to raise the confidence level of the PEA to feasibility level, and secure financing to carry the Project forward. In detail:
- Tetrahedrite concentrate is not particularly common and there are limited data points upon which to base potential smelter terms. Company dialog with various smelters has established that 10 to 20 kilogram sized-samples need to be produced for smelter testing and subsequent commercial bids.
- Among other issues, engineering work beyond the PEA would focus on material processing methodology to optimize the Project's flowsheet, while additional drilling, particularly southwest along strike of the Strieborná deposit above level 6, could extend the mineralization zone adjacent to existing infrastructure.
- As the Company advances the Project, financing will be necessary to continue with site activities (rehabilitation, dewatering, etc.) and engage with engineering and geological consultants.
Non-U.S. GAAP Performance Measurement
"Cash Costs" is a non-U.S. GAAP Performance Measurement. This performance measure is included because this statistic is widely accepted as the standard of reporting cash costs of production in North America. This performance measure does not have a meaning within U.S. GAAP and, therefore, amounts presented may not be comparable to similar data presented by other mining companies. This performance measure should not be considered in isolation as a substitute for measures of performance in accordance with U.S. GAAP.
PEA PREPARATION and QUALIFIED PERSONS
The PEA was completed independently by AGP Mining Consultants Inc. ("AGP"), Toronto, Ontario and Mine Development Associates ("MDA"), Reno, Nevada. The information in this news release that relates to the PEA was prepared by: Gordon Zurowski, P.Eng., Principal Mining Engineer, Geoffrey Challiner, C.Eng, Chief Mining Engineer (AGP), Andy Holloway, P.Eng Principal Metallurgist all of AGP, each of whom are independent of Global and are recognized as a Qualified Person ("QP") within the meaning of ("NI 43-101") The resource was prepared by Steven Ristorcelli, C.P.G, Principal Geologist with MDA and is independent of Global and recognized as a Qualified Person ("QP") within the meaning of ("NI 43-101").
William Bond C.P.G., M.Sc., Geol. and VP Exploration for Global is a Qualified Person as defined by NI 43-101 and has approved this news release.
A NI 43-101 compliant Technical Report, supporting the PEA and updated mineral resource estimate ("PEA Report") will be filed on SEDAR within 45 days.
FORWARD-LOOKING STATEMENTS AND FORWARD-LOOKING INFORMATION: This news release contains certain "forward-looking statements" within the meaning of applicable Canadian securities laws. Forward-looking statements and forward-looking information are frequently characterized by words such as "plan," "expect," "project," "intend," "believe," "anticipate", "estimate" and other similar words, or statements that certain events or conditions "may" or "will" occur.
FORWARD-LOOKING STATEMENTS are based on the opinions and estimates of management at the date the statements are made, and are subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking statements. These factors include the inherent risks involved in the exploration and development of mineral properties, the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of project cost overruns or unanticipated costs and expenses, uncertainties relating to the availability and costs of financing needed in the future and other factors. The Company undertakes no obligation to update forward-looking statements if circumstances or management's estimates or opinions should change. The reader is cautioned not to place undue reliance on forward-looking statements.
Readers are advised that National Instrument 43-101 of the Canadian Securities Administrators requires that each category of mineral reserves and mineral resources be reported separately. Readers should refer to the continuous disclosure documents filed by Global and available at www.sedar.com, for detailed information, which is subject to the qualifications and notes set forth therein.
The mineral resources are reported in accordance with Canadian Securities Administrators' National Instrument 43-101 and have been estimated in conformity with generally accepted CIM Estimation of Mineral Resource and Mineral Reserves Best Practices Guidelines. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resource will be converted into mineral reserve.
Neither the TSX Venture Exchange nor the Investment Industry Regulatory Organization of Canada accepts responsibility for the adequacy or accuracy of this press release.