The information on the Escalones Project contained herein was derived from the NI 43-101 Technical Report entitled “Mineral Resource Estimate for the Escalones Copper Project, Santiago Metropolitan Region, Chile” and dated August 18, 2020, with an effective date of June 30, 2020 and filed on SEDAR. Please refer to this Technical Report for important technical and other disclosures.
The Escalones copper-gold porphyry project lies 35 km east of El Teniente, one of the world’s largest underground copper mines, and within the renowned Chilean porphyry copper belt that runs north-south in the central Andes Mountains. The project has excellent infrastructure, including road access, electricity, access to seaports, and a gas pipeline that crosses the 70 square km property.
The Escalones deposit was discovered in 1996 through greenfield exploration work by Ralph Fitch, former President and CEO of General Minerals Corporation, and Felipe Malbran, the former Vice President of Exploration, South America.
Mineralization & Geology
Escalones has Indicated resources of 185 million tonnes of 0.33% copper (0.37% CuEq) and additional Inferred resources of 254 million tonnes of 0.39% copper (0.43% CuEq), based on nearly 25,000 metres of drill core from 53 holes. Significant molybdenum, gold and silver accompany the copper. The mineralization sits within a four square-kilometer area of hydrothermal alteration comprising quartz-sericite, potassic, and calc-silicate alteration assemblages. Coincident copper, gold and silver geochemical anomalies are associated with replacement-style “skarn” mineralization hosted in calcareous sedimentary rocks that flank central porphyritic intrusive rocks with porphyry-style (fracture-fill and disseminated) mineralization.
Copper mineralization at Escalones occurs primarily as the sulphides chalcopyrite, bornite, and covellite, which are partially to completely replaced within about 300m of the surface with secondary copper oxides, sulphates and carbonates. This replacement has led to higher grades at shallower depths, and, since the mineralization sits within a high-standing ridge, makes it amenable to surface mining.
A NI 43-101 Technical Report prepared by Hard Rock Consulting, LLC titled, “Mineral Resource Estimate for the Escalones Copper Project, Santiago Metropolitan Region, Chile” and dated August 18, 2020, with an effective date of June 30, 2020 (the “Escalones Technical Report”) updated the maiden resource estimate of 2013 (see link at top of page).
A key opportunity identified in the technical report is that approximately 60% of the estimated resource is above a base of enrichment surface and may be more beneficial to process through a heap-leach process. Assuming this mineralization proves to be favourable to a heap leach scenario, the mining costs could be lowered, which would result in a lower copper-only cutoff of 0.15%, which has similar grade and tonnes as the 0.20% CuEq cut-off listed in the technical report (207Mt at 0.31% copper Indicated and 284Mt at 0.37% copper Inferred).
The recovery of gold and silver would have to be evaluated on a possible on-off leach pad to see if recovery of these metals would be economic through this processing method.
Escalones Resource Estimate (June 30, 2020)
*Copper Equivalent (CuEq) is calculated based on a long-term copper price of US$3.23/lb; gold price of US$1,580/oz; silver price of US$18.63/oz; assumed combined operating ore costs of US$11.50/t (process, general and administrative and mining taxes); refining & smelting costs of $0.25/lb of CuEq; metallurgical recoveries of 75% for copper, 55% for gold and 65% for silver, and a 2% royalty.
Mineral resources that are not mineral reserves do not have demonstrated economic viability. Inferred mineral resources are that part of the mineral resource for which quantity and grade or quality are estimated on the basis of limited geologic evidence and sampling, which is sufficient to imply but not verify grade or quality continuity. Inferred mineral resources may not be converted to mineral reserves. It is reasonably expected, though not guaranteed, that the majority of Inferred mineral resources could be upgraded to Indicated mineral resources with continued exploration. Mineral resources are captured within an optimized pit shell and meet the test of reasonable prospects for economic extraction.
Several programmes of metallurgical testing on Escalones mineralization were completed between 2012 and 2013. Tests focused on the recovery of the copper, gold, silver, molybdenum and gallium by conventional flotation, acid leaching, and a combination of both (flotation followed by acid leaching of sulphide tailings and oxide scavenger concentrates).
The standard sulfuric acid leach metallurgical test achieved average copper extraction of 77%, ranging from 66 to 96% from mixed copper oxide-sulfide mineralization (eight composite samples). Copper sulphide flotation was also successful and rougher-cleaner flotation testing of the porphyry material achieved 25-34% copper concentrate grades at high recovery and low findings of all key impurities.
The base of enrichment is currently defined by the visual down-hole limits of oxidized and secondary copper sulphide minerals. The technical report recommends that future metallurgical studies investigate the upper enriched copper-oxide and secondary mineralization in all rock types. World Copper plans to submit samples of core sampling rejects for sequential copper leach analysis as a first important step in further defining acid soluble mineralization at Escalones.
The Escalones deposit remains open to expansion laterally and down dip, with only roughly half of the alteration zone drilled to date. Coincident geophysical anomalies indicate there is substantial expansion potential to both the skarn and porphyry mineralization. Interpretation of ZTEM resistivity and aeromagnetic surveys show several large areas of yet untested conductivity and magnetic anomalies which may represent potential additional mineralization. There are also several large outlying colour anomalies with sparse but encouraging surface sampling that could become future drill targets.
Cautionary Note Regarding Forward-Looking Statements
Forward Looking Information: this webpage and linked content includes certain information that may be deemed “forward looking information”. Forward-looking information can generally be identified by the use of forward-looking terminology such as “may”, “will”, “expect”, “intend”, “estimate”, “anticipate”, “believe”, “continue”, “plans” or similar terminology. All information in this release, other than information of historical facts, including, without limitation, the potential of the general future plans and objectives for the Escalones project, the completion of the Plan and receipt of shareholder and regulatory approval therefor, the likelihood of receipt of value from the Retained Right, the availability of financing to World Copper Ltd. (“the Company”) and the Company’s plan in relation to its listing review are forward-looking information that involve various risks and uncertainties. Although the Company believes that the expectations expressed in such forward-looking information are based on reasonable assumptions, such expectations are not guarantees of future performance and actual results or developments may differ materially from those in the forward-looking information. Forward-looking information is based on a number of material factors and assumptions. Factors that could cause actual results to differ materially from the forward-looking information include changes in project parameters as plans continue to be refined, future metal prices, availability of capital and financing on acceptable terms, general economic, market or business conditions, regulatory changes, delays in receiving approvals, and other risks detailed herein and from time to time in the filings made by the Company with securities regulatory authorities in Canada. Mineral exploration and development of mines is an inherently risky business. Accordingly, actual events may differ materially from those projected in the forward-looking information. For more information on the Company and the risks and challenges of our business, investors should review our continuous disclosure filings which are available at www.sedar.com. Readers are cautioned not to place undue reliance on forward-looking information. The Company does not undertake to update any forward looking information, except in accordance with applicable securities law.
John Drobe P.Geo., World Copper's Exploration Manager, and a qualified person as defined by National Instrument 43-101, has reviewed the technical information that forms the basis for this webpage.