Source:
p. 20
PPX (PPX Mining Corp.) holds 100% ownership of the Igor mining concessions, which are of the metallic type, through its wholly owned subsidiary Sienna Minerals S.A.C.
Deposit Type
- Porphyry
- Epithermal
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
Field evidence suggests that the Igor project mineralization belongs to the epithermal type of gold-silver deposit (Guilbert and Park, 1986). In general, epithermal gold-silver deposits are composed of structurally or stratigraphically controlled disseminations or veins that form in a shallow environment (less than or about 1.5 km) and are hosted by volcanic or sedimentary rocks. The mineralization is dominated by gold and silver but can contain variable amounts of copper, lead, and zinc.
Igor project mineralization occurs within four primary target areas: Callanquitas, Domo, Tesoros, and Portachuelos. Mineralization within the property often occurs at the transition zone from Chimú up into the Santa and Carhuez rocks. There is a spatial association of dacite porphyry dikes emplaced within structural breccias with both structural and manto-style mineralization.
The Callanquitas area, which is on the northwest side of the Igor anticline, is the focus of the current resource estimate and pre feasibility technical analyses. Domo and Tesoros, within the east and southeast sides of the anticline, respectively, have had limited drilling and both are areas of minor artisanal mining activity. Portachuelos is an exploration target on the southwest limb of the anticline on trend south of Callanquitas.
Callanquitas Veins
The Callanquitas veins (Callanquitas Este, Callanquitas Oeste and Cianuro) occur within a north-south striking zone of multiple, anastomosing to divergent faults that extends over a length of 2,400 meters. Individual veins can be up to 1.5km long with thicknesses between 0.2 to 8.2m. The Callanquitas structures are open along strike to the south and north and also at depth.
The Callanquitas mineralization is considered an intermediate-sulfidation type, consisting of mineralized structural breccias that originally contained variable quantities of pyrite, arsenopyrite, and minor chalcopyrite. These sulfide minerals were subsequently strongly oxidized to significant depths. The primary mineralized structures (Callanquitas Este and Oeste structures), are nearly vertical and steep westerly dips are common.
The structures cut through a sequence of sandstone, siltstone and quartzite. The silicified sandstone and quartzite units were more amenable to brecciation and therefore more favorable for migrating hydrothermal fluids and mineralization. The dacite intrusive rocks are generally argillically-altered and although the mineralized structures cut through the dacite, the general lack of brecciation and development of open-space renders the intrusions a poor host for mineralization.
Detailed underground mapping by PPX, along with a re-logging of early core holes, indicates multiple stages of veining, brecciation, alteration, and mineralization. The initial event appears to be emplacement of quartz veins within faults, followed by multiple stages of hydrothermal brecciation (“HBx”) with associated pervasive silicification, which was then cut by sulfide veinlets. The last stage is a fault gouge or tectonic breccia (“TBx”) usually occurring adjacent or cross-cutting the HBx. The highest gold grades are associated with the early quartz and HBx while increased silver occurs with the late-stage sulfide veinlets. The TBx is argillized and appears to be mostly post-mineral in the paragenesis, though it often contains low-grade gold in the range of 0.5 to 1.0g Au/t. Gold within the TBx is believed to be due to the presence of mineralized clasts within the argillized fault gouge, though there are exposures underground of TBx with oxidized veinlets that can assay up to multiple grams of gold. It is possible that there are multiple TBx events with early-stage faulting prior to the formation of silica-sulfide veinlets.
Drilling indicates that mineralization in the Callanquitas Este and Oeste veins occurs over a 1,400 meters north-south strike length and extends to depths of up to 500 meters below the topographic surface. Oxidation within the mineralized structures occurs to depths of 200 to 300 meters below surface. Ag/Au ratios are generally low (about 10:1) in the oxide portion of the deposit, but can increase to over 100:1 at the oxide-sulfide interface. The change in Ag/Au ratios is not just related to supergene enrichment, but also represents the occurrence of late-stage, silver-rich, silica-sulfide veinlets which cut the more gold-rich hydrothermal breccias.
Domo
Domo mineralization occurs within a zone of bedding-parallel mantos and perpendicular veins along the crest of the southeast end of the Igor Anticline. Gold and silver mineralization is controlled by a series of northeast-southwest trending faults and occurs as oxidized pyritic breccias with variable silicification.
Tesoros
Tesoros mineralization consists of gold-bearing veins, breccias, and mantos along a major north- northeast striking fault that has localized the emplacement of dacitic porphyries and pebble dikes.
Portachuelos
Portachuelos lies along the southern extension of the Callanquitas structure zone in an area where the north-south Callanquitas structures, and also the northeast-trending Domo structures, trend to the south and southwest into the western portion of the Huevo de Condor dacite porphyry stock. It is an early stage exploration target which is currently the focus of PPX exploration drilling.
Mining Methods
- Cut & Fill
- Drift & Fill
- Backfill
Summary:
The Igor mine will be accessed via two declines and a system of internal ramps.
The modified cut and fill mining method will start by mining all the capital development on alevel including the decline, station levels, and raises. After the capital development for a level is complete, the access drive will be mined from the station level to the ore drive at a -12.5% grade. The ore drive runs along strike of the orebody. After the ore drive is mined out, the first lift will be mined by drilling up holes into the back and blasting down. The material will be moved out of the drift via an underground loader and trucks. After the first lift is mined out, the ore drive will be filled with waste rock via an underground loader and trucks. The access drive will then be adjusted to access the first lift. This process will continue until the sill pillar is reached .
The level layout consists of a decline, level station, exhaust raise, intake raise, level access, ore drives, and stopes. The raises will also be used as a material pass system. The access drift is designed at -12.5% grade. The access drift will be adjusted upwards after each lift is mined and filled. The resulting access drift will be at +12.5% grade. The decline is also designed at -12.5% grade.
All mining, including production and development, will be done by mining contractors who will provide the required mobile equipment.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
.......................
|
21" x 32"
|
|
1
|
Cone crusher
|
.......................
|
|
|
1
|
Vertical shaft impact crusher (VSI)
|
.......................
|
|
|
1
|
Summary:
Three stages of crushing are planned for the Callanquitas mineralized material prior to agglomeration and stacking on the heap-leach pad.
Primary Crushing
The ROM ore will be transported in trucks of 15m 3 with a net load of 20 tonnes, and this mineral will be discharged both in the coarse hopper and in the coarse stockpile depending on the availability of storage. The capacity of the ROM hopper will be 100 tonnes wet, and by means of a lower feeder the ore is discharged into a vibratory grizzly with 50mm opening (minimum). The oversize material will feed to a 53.34 centimeters by81.28 centimeters jaw crusher and the undersize or screened material will fall to a conveyor belt No. 1. The jaw crusher has been selected to operate with a set opening set of 38 mm. The product of the jaw crusher will fall to conveyor belt No. 1.
Both the jaw crusher product and the grizzly undersize with 65% minus 25mm will go to a 1.524 meter x 4.88 meter vibrating screen of a single deck with a 19mm opening. The +19mm oversize returns, through conveyor belt N°2, to the 0.91 meter cone crusher. This unit works with a 19mm discharge opening and the crushed ore product of the conical crusher, whose granulometry is 60% minus 19mm, will unload to the conveyor belt N°1, joining with the product of the jaw crusher and undersize of the grizzly, to enter the vibrating screen again.
Fine Crushing
Discharge from the vibrating screen will be 100% less 19mm and it will enter a vibrating sieve N°2 of 9mm mesh. The oversize from vibratory sieve N°2 enters the vertical tertiary impact crusher (“VSI”), which discharges a product of 100% - 0.9525cm. This fine product falls to conveyor belt N°3 that joins with vibrating screen N°2 and both products go to the agglomeration system. The feed conveyor will include a conveyor belt weight meter for measuring material throughput.
Crushed-Ore Stockpile and Conditioning
The crushed product from the crushing circuit will be stockpiled with a radial stacker. Two loading stations with hoppers and belt feeders will receive stockpiled material with the use of a front-end loader and discharge into a transfer conveyor. The transfer conveyor will discharge into a trommel for mixing leach material with cement and lime. Lime will be added directly to the crushed product reclaim conveyor. A 70 tonne lime silo with a reclaim device and screw feeder will allow metering the lime into the conveyor.
Processing
- Filter press plant
- Smelting
- Heap leach
- Merrill–Crowe
- Cyanide (reagent)
- Sodium carbonate (reagent)
Flow Sheet:
Summary:
The process plant design considers a heap-leach operation for the LOM. A two-stage development is considered for the heap-leach operation: stage 1 is for mining and treating oxide ores at the rate of 350tpd and stage 2 will mine and heap-leach at the rate of 500tpd. In this evaluation, there are no provisions to implement grinding facilities for treating material from the mine. The estimated reserves are 1,030,000 tonnes, establishing a project LOM of 8.6 years. The process design considers gold and silver recoveries by cyanide heap- leaching of 80% and 33%, respectively.
Oxide ore will be crushed in three stages and then processed in a heap leach operation that will utilize a single, multiple-lift and multiple-use leach pad. The planned operation requires 8,000m 2 of leach pad space for the first two years of operation at a nominal feed rate of 350tpd. After the second year, the leached material will be reclaimed and placed as backfill in the mine. Concurrent with this recl ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| 80 |
Gold
|
Head Grade, g/t
| 4.1 |
Silver
|
Recovery Rate, %
| 33 |
Silver
|
Head Grade, g/t
| 104.08 |
Projected Production:
Commodity | Product | Units | LOM |
Gold
|
Payable metal
|
koz
| 107 |
Gold
|
Metal in doré
|
koz
| 108 |
Silver
|
Payable metal
|
koz
| ......  |
Silver
|
Metal in doré
|
koz
| ......  |
Gold Equivalent
|
Payable metal
|
koz
| ......  |
Operational Metrics:
Metrics | |
Daily ore mining rate
| 350 t * |
Ore tonnes mined, LOM
| 1,030 kt * |
Total tonnes mined, LOM
| 1,242 kt * |
Daily processing capacity
| 350 t * |
Daily processing rate
| 350 t * |
Tonnes processed, LOM
| 1,030,000 t * |
Annual processing rate
| 126,000 t * |
* According to 2018 study.
Reserves at December 3, 2018:
Mineral Resources are tabulated on a gold-equivalent (“AuEq”) cutoff grade of 2.0g AuEq/t.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Oxide
|
8,000 t
|
Gold
|
4.56 g/t
|
1,000 oz
|
Proven
|
Oxide
|
8,000 t
|
Silver
|
32.3 g/t
|
8,000 oz
|
Proven
|
Oxide
|
8,000 t
|
Gold Equivalent
|
4.74 g/t
|
1,000 oz
|
Probable
|
Oxide
|
1,022,000 t
|
Gold
|
4.09 g/t
|
134,000 oz
|
Probable
|
Oxide
|
1,022,000 t
|
Silver
|
104.6 g/t
|
3,437,000 oz
|
Probable
|
Oxide
|
1,022,000 t
|
Gold Equivalent
|
4.66 g/t
|
153,000 oz
|
Proven & Probable
|
Oxide
|
1,030,000 t
|
Gold
|
4.1 g/t
|
136,000 oz
|
Proven & Probable
|
Oxide
|
1,030,000 t
|
Silver
|
104.1 g/t
|
3,445,000 oz
|
Proven & Probable
|
Oxide
|
1,030,000 t
|
Gold Equivalent
|
4.66 g/t
|
154,000 oz
|
Measured
|
Oxide
|
109,000 t
|
Gold
|
5.32 g/t
|
19,000 oz
|
Measured
|
Oxide
|
109,000 t
|
Silver
|
61.7 g/t
|
215,000 oz
|
Measured
|
Oxide
|
109,000 t
|
Gold Equivalent
|
5.59 g/t
|
20,000 oz
|
Indicated
|
Oxide
|
1,361,000 t
|
Gold
|
4.67 g/t
|
204,000 oz
|
Indicated
|
Oxide
|
1,361,000 t
|
Silver
|
113.4 g/t
|
4,962,000 oz
|
Indicated
|
Oxide
|
1,361,000 t
|
Gold Equivalent
|
5.17 g/t
|
226,000 oz
|
Measured & Indicated
|
Oxide
|
1,470,000 t
|
Gold
|
4.72 g/t
|
223,000 oz
|
Measured & Indicated
|
Oxide
|
1,470,000 t
|
Silver
|
109.5 g/t
|
5,177,000 oz
|
Measured & Indicated
|
Oxide
|
1,470,000 t
|
Gold Equivalent
|
5.21 g/t
|
246,000 oz
|
Inferred
|
Sulphide
|
269,000 t
|
Gold
|
2.97 g/t
|
26,000 oz
|
Inferred
|
Oxide
|
344,000 t
|
Gold
|
4.58 g/t
|
51,000 oz
|
Inferred
|
Sulphide
|
269,000 t
|
Silver
|
159.1 g/t
|
1,378,000 oz
|
Inferred
|
Oxide
|
344,000 t
|
Silver
|
124.6 g/t
|
1,376,000 oz
|
Inferred
|
Sulphide
|
269,000 t
|
Gold Equivalent
|
3.68 g/t
|
32,000 oz
|
Inferred
|
Oxide
|
344,000 t
|
Gold Equivalent
|
5.13 g/t
|
57,000 oz
|
Corporate Filings & Presentations:
Document | Year |
...................................
|
2021
|
...................................
|
2020
|
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|
2020
|
...................................
|
2019
|
...................................
|
2019
|
Pre-Feasibility Study Report
|
2018
|
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