HIGHLIGHTS
- Up to 4.5x upgrade ratios achieved across all grade profiles for samples tested within the
Vermelhos Mine and for high-grade samples from thePilar Mine at minimal copper loss after sorting, averaging only 9.8% for screened sorter feed samples. - Upgrade ratios of approximately 1.4x to 2.0x achieved for several open pit deposits throughout the Curaçá Valley with slightly higher copper losses, averaging 15.5% to 26.0%, for screened sorter feed samples tested at the Surubim and Suçuarana Mines, low-grade development material from within the
Pilar Mine and material from a historicAngicos Mine stockpile. - Based on the success of the trial campaign and economic evaluations, ore sorting is expected to be integrated into the Company’s upcoming life-of-mine plan update with a focus on implementing the technology within the
Vermelhos District as a result of the excellent response to ore sorting and potential savings in transport costs. - Potential ancillary benefits of ore sorting implementation include reduced consumption of fresh-water, diesel and electricity and reduced flotation tailings generated per tonne of copper produced – substantially advancing towards achieving the Company’s long-term environmental and sustainability commitments within the Curaçá Valley.
Commenting on the results of the campaign,
The ore sorting unit, currently installed at the
Ore Sorting Trial Campaign Results
A total of approximately 29,000 tonnes of material from eight different sources of material throughout the Curaçá Valley were run at commercial throughput rates through the Company’s X-ray Fluorescence (“XRF”) ore sorting machine from early 2020 through September. The XRF sorting unit was installed at the
For each deposit tested, and for material from the
Upgrade ratios were determined across a range of mass yields using the selectivity curves generated for each source. Results of the program across a range of mass yields are further detailed in Table 1:
Table 1: Ore Sorting Trial Campaign Results at Varying Mass Yields
Results at Selected Ore Sorting Mass Yield[1] | |||||||
Sample Tested (Tonnes) | Sample Head Grade (Cu %) | 20% | 40% | 60% | 80% | ||
Vermelhos HG Sample | 4,569 | 2.71 | |||||
Sort Product Grade (Cu%) | 12.22 | 6.39 | 4.37 | 3.34 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 4.50x | 2.35x | 1.61x | 1.23x | |||
Calculated Copper Loss (%) | 9.8% | 5.7% | 3.2% | 1.4% | |||
Vermelhos MG Sample | 4,246 | 1.21 | |||||
Sort Product Grade (Cu %) | 5.46 | 2.85 | 1.95 | 1.49 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 4.52x | 2.36x | 1.61x | 1.23x | |||
Calculated Copper Loss (%) | 9.8% | 5.7% | 3.2% | 1.4% | |||
Vermelhos LG Sample | 9,109 | 0.80 | |||||
Sort Product Grade (Cu %) | 3.61 | 1.89 | 1.29 | 0.99 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 4.49x | 2.35x | 1.61x | 1.23x | |||
Calculated Copper Loss (%) | 9.8% | 5.7% | 3.2% | 1.4% | |||
Pilar Mine HG (Deepening) | 1,161 | 1.97 | |||||
Sort Product Grade (Cu %) | 8.86 | 4.64 | 3.17 | 2.43 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 4.49x | 2.35x | 1.61x | 1.23x | |||
Calculated Copper Loss (%) | 10.0% | 5.8% | 3.3% | 1.5% | |||
904 | 0.33 | ||||||
Sort Product Grade (Cu %) | 1.08 | 0.65 | 0.48 | 0.39 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 3.33x | 1.99x | 1.48x | 1.20x | |||
Calculated Copper Loss (%) | 34.4% | 21.4% | 12.5% | 5.7% | |||
Surubim Mine | 940 | 0.30 | |||||
Sort Product Grade (Cu %) | 0.97 | 0.59 | 0.44 | 0.35 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 3.20x | 1.93x | 1.43x | 1.16x | |||
Calculated Copper Loss (%) | 35.0% | 21.8% | 12.8% | 5.8% | |||
Suҫuarana Mine | 3,753 | 0.27 | |||||
Sort Product Grade (Cu %) | 0.69 | 0.46 | 0.36 | 0.31 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 2.59x | 1.73x | 1.36x | 1.15x | |||
Calculated Copper Loss (%) | 48.8% | 31.7% | 19.2% | 8.9% | |||
Angicos Mine Stockpile | 4,216 | 0.38 | |||||
Sort Product Grade (Cu %) | 1.04 | 0.67 | 0.52 | 0.44 | |||
Upgrade Ratio (Sort Product Grade/Feed Grade) | 2.73x | 1.77x | 1.37x | 1.15x | |||
Calculated Copper Loss (%) | 45.5% | 29.2% | 17.5% | 8.1% | |||
[1] Ore sorting results presented excluding minus 30 millimeter material which is not amenable to upgrading. Fines generated range from 15% to 30% depending on source tested. Calculated results at selected mass yields are based on selectivity curves generated during the ore sorting trial-campaign and reflect desired selectivity of sorting set points. Vermelhos HG, MG and LG refers to high-grade, medium-grade and low-grade, respectively.
QUALITY ASSURANCE / QUALITY CONTROL
Vale do Curaçá Property
All sample preparation is performed in MCSA’s secure on-site laboratory. Total copper is determined using a nitric-hydrochloric acid digestion and Atomic Absorption Spectrometry (“AAS”) and/or Titration. Oxide copper values are determined using sulfuric acid digestion followed by AAS. All sample results during the period have been monitored through a quality assurance – quality control (“QA/QC”) program that includes the insertion of certified standards, blanks, and pulp and reject duplicate samples. Regular check-assays are submitted to ALS Brasil Ltda’s facility located in Vespasiano,
ABOUT
Signed: “ | For further information contact: |
Makko DeFilippo, Vice President, Corporate Development | |
(604) 429-9244 | |
info@erocopper.com | |
CAUTION REGARDING FORWARD LOOKING INFORMATION AND STATEMENTS This Press Release contains “forward-looking information” within the meaning of applicable Canadian securities laws. Forward-looking information includes statements that use forward-looking terminology such as “may”, “could”, “would”, “will”, “should”, “intend”, “target”, “plan”, “expect”, “budget”, “estimate”, “forecast”, “schedule”, “anticipate”, “believe”, “continue”, “potential”, “view” or the negative or grammatical variation thereof or other variations thereof or comparable terminology. Such forward-looking information includes, without limitation, statements with respect to the representativeness of the material tested in the trial campaign to actual results of each of the mines tested during the campaign, the timing and expected outcome of the Company’s updated life-of-mine plan including the potential implementation of ore sorting in those plans at any of the Company’s operations including the
Forward-looking information is not a guarantee of future performance and is based upon a number of estimates and assumptions of management in light of management’s experience and perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances, as of the date of this Press Release including, without limitation, assumptions about: favourable equity and debt capital markets; the ability to raise any necessary additional capital on reasonable terms to advance the production, development and exploration of the Company’s properties and assets; future prices of copper and other metal prices; the timing and results of exploration and drilling programs; the accuracy of any mineral reserve and mineral resource estimates; the geology of the Vale do Curaçá Property,
Furthermore, such forward-looking information involves a variety of known and unknown risks, uncertainties and other factors which may cause the actual plans, intentions, activities, results, performance or achievements of the Company to be materially different from any future plans, intentions, activities, results, performance or achievements expressed or implied by such forward-looking information. Such risks include, without limitation the risk factors listed under the heading “Risk Factors” in the Annual Information Form of the Company for the year ended
Although the Company has attempted to identify important factors that could cause actual actions, events, conditions, results, performance or achievements to differ materially from those described in forward-looking information, there may be other factors that cause actions, events, conditions, results, performance or achievements to differ from those anticipated, estimated or intended.
The Company cautions that the foregoing lists of important assumptions and factors are not exhaustive. Other events or circumstances could cause actual results to differ materially from those estimated or projected and expressed in, or implied by, the forward-looking information contained herein. There can be no assurance that forward-looking information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such information. Accordingly, readers should not place undue reliance on forward-looking information.
Forward-looking information contained herein is made as of the date of this press release and the Company disclaims any obligation to update or revise any forward-looking information, whether as a result of new information, future events or results or otherwise, except as and to the extent required by applicable securities laws.
GENERAL Information of a scientific or technical nature in respect of the Vale do Curaçá Property included in this press release is based upon the Vale do Curaçá technical report entitled “2019 Updated Mineral Resources and Mineral Reserves Statements of Mineração Caraíba’s Vale do Curaçá Mineral Assets, Curaçá Valley”, dated
Please see the 2019 Technical Report filed on the Company’s profile at www.sedar.com, for details regarding the data verification undertaken with respect to the scientific and technical information and for additional details regarding the deposits and stockpiles tested, including interpretations, the QA/QC employed, sample, analytical and testing results and for additional details regarding the Mineral Resource and Mineral Reserve estimates of the Vale do Curaçá Property.
Cautionary Notes Regarding Mineral Resource and Reserve Estimates In accordance with applicable Canadian securities regulatory requirements, all mineral reserve and mineral resource estimates of the Company disclosed or incorporated by reference in this press release have been prepared in accordance with NI 43-101 and are classified in accordance with the CIM Standards.
Mineral resources which are not mineral reserves do not have demonstrated economic viability. Pursuant to the CIM Standards, mineral resources have a higher degree of uncertainty than mineral reserves as to their existence as well as their economic and legal feasibility. Inferred mineral resources, when compared with Measured or Indicated mineral resources, have the least certainty as to their existence, and it cannot be assumed that all or any part of an Inferred mineral resource will be upgraded to an Indicated or Measured mineral resource as a result of continued exploration. Pursuant to NI 43-101, Inferred mineral resources may not form the basis of any economic analysis. Accordingly, readers are cautioned not to assume that all or any part of a mineral resource exists, will ever be converted into a mineral reserve, or is or will ever be economically or legally mineable or recovered.
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