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Peru

Antilla Project

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Overview

Mine TypeOpen Pit
StagePreliminary Economic Assessment
Commodities
  • Copper
  • Molybdenum
Mining Method
  • Truck & Shovel / Loader
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Owners

SourceSource
CompanyInterestOwnership
Panoro Minerals Ltd. 25 % Indirect
Calisto Cobre Resources Corp. 75 % Indirect
On December 3, 2021, Panoro Minerals Ltd. (the Company) sold 75% of its interest in Antilla Copper, S.A. (“Antilla Copper”), a subsidiary of the Company. Payment #1 was received of $CA 10.0M ($US 7.3M) on closing in December 2021.

On March 11, 2024, Panoro Minerals Ltd. received approximately CA $2.7M (Payment #2) from Calisto Cobre Resources Corp. (formerly Heeney Capital Acquisition Company) as per terms of the Company’s sale in December 2021 of 90% of the shares of Antilla Copper S.A.

Payment #3 of $CA 7.0M ($US 5.2M) from Calisto is payable within 12 months of Calisto obtaining drilling permits and completing land access agreements at the Antilla Project. Payment #4 will be due after Calisto completes a study of the Antilla Project with Panoro receiving 13% of the estimated Net Present Value, less the $CA 20M ($US 14.8M) total of Payments #1, #2 and #3. In addition, Panoro will retain a 10% interest in the Antilla Project plus a 2% NSR royalty.

Contractors

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Deposit type

  • Porphyry

Summary:

The mineralization identified to date on the property is consistent with a supergene enrichment blanket hosted in a sandstone-quartzite package of Soraya Formation associated with an Andean-type copper-molybdenum porphyry system.

The most important mineralization encountered to date on the property is a tabular body of fracture-controlled and disseminated chalcocite and chalcopyrite with minor molybdenite-coated fractures overlain by a barren, leached zone of variable thickness. The tabular zone strikes 50 degrees and dips 20 degrees to the east over an area 1.2 kilometres long and 1.2 kilometres wide. The supergene chalcocite mineralization has a true thickness of 40 to 80 metres. Associated with the chalcocite mineralization is weak sericitization, chloritization, and silicification of arenite and quartzite. The strongest chalcocite mineralization is associated with brittle faults. Below the chalcocite mineralization, low grade disseminated chalcopyrite, bornite, and molybdenite mineralization occurs. Altered, weakly-mineralized porphyritic felsic intrusives are associated with the hypogene mineralization. Unaltered, unmineralized porphyritic dikes cut the mineralization.

The most economically significant mineralization encountered to date on the property is fracture-controlled and disseminated chalcocite. The chalcocite occurs as:

1. Sooty or scaly coatings 1 millimetre wide, filled to partially open fractures;
2. Sooty coatings on rock fragments and rock flour encountered in intense fracture or fault zones over widths of 1 to 10 metres;
3. Selvages on sub-centimeter width quartz veinlets;
4. Occasionally as disseminated grains or coating disseminated grains of primary chalcopyrite in zones of more intense fracturing and silicification.

Chalcocite is enriched in the secondary sulphide enrichment zone. Molybdenite occurs in fine fractures and as grains within sub-centimetre wide quartz veinlets in the primary sulphide, secondary sulphide and Main Porphyry. Chalcopyrite occurs as disseminated grains and surface coatings along fractures and within quartz veinlets. Disseminated grains were also observed. Chalcopyrite in concentrations of up to 1% occurs in the Main Porphyry and in primary hypogene sulphide zones.

Copper grade increases three-fold from the primary sulphide zone to the secondary sulphide zone. The leached zone has copper grades approximately one third of those from the primary sulphide zone and an order of magnitude less than the secondary sulphide zone. The genetic model involving the removal of copper from primary mineralization in what is now the leached zone and re deposition as chalcocite in the secondary sulphide zone is well supported, given the distribution of copper grades among the mineralization zones. The Main Porphyry is weakly mineralized with copper, and the Late Porphyry contains little or no copper.

Molybdenum grade does not vary significantly between the primary sulphide, secondary sulphide, and leached zones, demonstrating the relative immobility of molybdenum in molybdenite during supergene processes. The highest concentrations of molybdenum occur in the Main Porphyry, a characteristic which is common to other porphyry and skarn deposits in the region.

In general, gold, silver, zinc, and lead concentrations are very low in all mineralization types. These metals do not show significant enrichment or depletion trends between the primary, secondary, and leached zones, and are not especially enriched or depleted in either of the porphyries.

Hydrothermal alteration is restricted to the development of secondary sericite, biotite, and quartz, suggesting that the relatively inert quartzite and low water to rock ration of alteration result in the subtle alteration observed at Antilla. Unaltered quartzite lacks significant quantities of primary aluminosilicates to alter to large quantities of sericite, chlorite, biotite, and clay typical of potassic, phyllic, propylitic, and advanced argillic alteration zones common in other porphyry zones.

Due to difficulties of stratigraphic correlation within the relatively monotonous quartzite and arenite of the Soraya Formation, a detailed understanding of the structural geology of the Antilla deposit is still under development. However, current genetic interpretations for the Antilla deposit place an emphasis on structural features at regional and local scale as mineralization controls.

The main mineralization types or zones are similar to many other porphyry deposits. The zones found at Antilla are primary sulphide, secondary sulphide, and oxide in the leached cap overlying the deposit. The secondary sulphide zone forms a relatively continuous, tabular chalcocite-enriched blanket that generally ranges from 60 to 120 metres thick. Borehole ANT-36-08 intersected a secondary sulphide zone 243 metres thick before encountering primary sulphide-style mineralization at 278 metres. The average thickness of the secondary sulphide zone is 92 metres.

The secondary sulphide zone is overlain by a leached cap that has an average thickness of 55 metres and generally ranges from 0 to 75 metres thick. The leach cap appears to thicken to the north and to the west where borehole ANT-64-08 encountered leached cap to a depth of 274 metres. It is interpreted that much of the leached cap overlying the main and southeastern portion of the secondary sulphides has been eroded bringing the secondary sulphide mineralization nearly to surface in some locations. The tabular secondary sulphide and leached cap zones are underlain by lower-grade primary sulphide mineralization. The depth extent of the primary sulphide mineralization is not known as it has only been tested by five or six boreholes.

Main Porphyry is weakly mineralized and is known to flank the primary and secondary sulphides and oxide zone to the east and west and at the northwest corner.

A discontinuous veneer of gravel, sand, talus, and colluvium overlies the deposit. Overburden ranges in thickness from 0 to 53 metres, averaging 12 metres. In addition to the mineralization zones, a very small zone of weak exotic-type or remobilized copper oxide mineralization has been found in overburden exposed in a road cut at the bottom of the hill slope, overlying the secondary sulphide blanket.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityProductUnitsAvg. AnnualLOM
Copper Payable metal M lbs 46787
Copper Cathode M lbs 48819

Operational metrics

Metrics
Daily ore mining rate 20,000 t *
Daily processing rate 19,944 t *
Daily processing capacity 20,000 t *
Annual mining rate 16,952 kt *
Annual ore mining rate 7.3 Mt *
Annual processing rate 7.3 Mt *
Stripping / waste ratio 1.38 *
Waste tonnes, LOM 163,439 kt *
Ore tonnes mined, LOM 118,667 kt *
Total tonnes mined, LOM 294,868 kt *
Tonnes processed, LOM 118,667 kt *
* According to 2018 study.

Production Costs

CommodityUnitsAverage
C1 cash costs Copper USD 1.51 / lb *  
C2 total cash costs Copper USD 1.82 / lb *  
Assumed price Copper USD 3.05 / lb *  
* According to 2018 study / presentation.

Operating Costs

Currency2018
OP mining costs ($/t milled) USD  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2018 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 552.7
Transportation (haulage) costs $M USD 4.2
G&A costs $M USD 89
Total OpEx $M USD  ......  Subscribe
Mining Taxes $M USD  ......  Subscribe
Income Taxes $M USD  ......  Subscribe
Total Taxes $M USD  ......  Subscribe
Royalty payments $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 5% $M USD  ......  Subscribe
Pre-tax NPV @ 10% $M USD  ......  Subscribe
Pre-tax NPV @ 7.5% $M USD  ......  Subscribe
After-tax NPV @ 5% $M USD  ......  Subscribe
After-tax NPV @ 10% $M USD  ......  Subscribe
After-tax NPV @ 7.5% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
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Required Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNamePhoneProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 11, 2018
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Jan 15, 2024

Aerial view:

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