Zafranal represents a classic example of an Andean style porphyry copper, gold, and molybdenum deposit.

Porphyry copper-gold mineralization occurs within a large roughly east-west trending hydrothermally altered zone that is more than 7 kilometres in length and as much as 1.7 kilometres in width in a north-south direction. Copper occurs within veins and stockworks and as disseminations in both the Zafranal Main zone and Victoria deposits. At the Zafranal Main zone deposit, primary (hypogene) mineralization is overlain by zones of secondary enrichment mineralization. Copper mineralization has been categorized, based on copper solubility, into leached, mixed, oxide, supergene and primary zones.

Zafranal Main zone.
Drilling on the Zafranal Main zone has demonstrated continuous mineralization over a strike length of at least 2,500 m, widths of between 500 to 800 m, and over a vertical range of up to 1,000 m. The types of copper mineralization are described as follows:

Leached cap and secondary enrichment

The large altered and mineralized area at Zafranal has a subdued colour anomaly. The deposit has been intensely leached with a well-developed leached cap over the top of the supergene-enriched horizon at depth. Very little hypogene sulfide mineralization is present in outcrop, having been strongly leached and/or altered. At surface all forms of sulfides are absent except for occasional pyrite along with chalcopyrite in some more silicified rocks where acid ground waters could not invade the rock and oxidize and leach it.

The best supergene enrichment zone is generally associated with phyllic alteration consisting of a sericite + quartz + chlorite/biotite + clays + pyrite assemblage. The thickness of this zone can reach up to 150 m – averaging 75 m throughout the deposit – with grades up to 7% Cu.

Copper oxides of chrysocolla, neotocite, malachite and azurite generally occur above the main supergene enriched blanket and below the leached cap. This type of oxide copper mineralization is associated with an intense phyllic alteration (sericite + quartz + clays). Oxide mineralization can be up to 50 m thick. The leached cap itself is 30 m to 200 m thick. The copper-oxide zone defines former supergene enrichment zones (paleoblanket) preserved within the oxidized leach zone.

Primary sulfide mineralization

Hypogene mineralization occurs as veins, stockworks, and disseminations in the Zafranal diorite and microdiorite units. The Zafranal diorite at surface contains consistent background copper amounts (typically between 1,000 ppm and 1,500 ppm Cu) and typically presents the highest surface geochemical anomalies on the property. At deeper levels higher-grade hypogene mineralization is closely associated to the intrusive contact with the cross cutting microdiorite. The overlying enriched blanket is much smaller than the underlying hypogene mineralization, though with much higher grades.

Primary sulfide mineralization at the Main zone is hosted mainly by the microdiorite and the Zafranal diorite. This primary mineralization is related to a potassic alteration zone with a quartzsecondary biotite-chlorite assemblage. Chalcopyrite is by far the most abundant copper species here and occurs both as disseminations and in veinlets. A- type and B-type veins (quartzchalcopyrite-pyrite and quartz-chalcopyrite-molybdenite respectively) are abundant at Zafranal and average copper grades range from 0.15% to 0.5% Cu, locally increasing up to 1% Cu.

Victoria zone

Mineralization at Victoria is predominantly hypogene and occurs as a tabular body parallel to the main foliation, suggesting that it predates or is contemporaneous with the principal deformation event. Chalcopyrite occurs both as fine-grained disseminations and as patches associated with veins and stockworks. Mineralization within the Victoria zone measures approximately 900 m along strike and up to 500 m width and drilling encountered it down to depths of up to 400 m below surface.

To assess reasonable prospects for eventual economic extraction, it was assumed that the Zafranal deposit would be mined utilizing open pit mining methods under a conceptual scenario of 55,000 tonnes per day production using conventional flotation to produce a concentrate grading 28% copper with credit for gold.

The proposed Zafranal mine will develop two open pits (Zafranal Main and Victoria) with a combined area of 2.47 km2 . The final pits will be 2.6 km long and 1.0 km wide and shall reach a maximum depth of 554 m.

The Zafranal Main pit has two exits on the south side and two on the north side to provide access to the, primary crusher, stockpiles and waste dumps. The main pit is 2,500 m long in the east- west direction and 1,000 m wide in the north-south direction. The pit bottom is at 2,280 m elevation, at the western end. The highest wall is about 456 m on the northeast side. The total area disturbed by the main pit is about 250 hectares.

To the east of the Main Pit, a small Victoria Pit was designed 950 m long and 500m wide, with the pit bottom at 2,532 m elevation, the highest wall of 180 m to the north and with 47 hectares of disturbed area.

The concentrator associated support facilities and utilities will process run-of-mine (ROM) ore delivered to the primary crusher and produce a copper-gold concentrate for sale. The process encompasses crushing of the ROM ore, grinding, flotation including regrind, and concentrate thickening and filtration to produce copper-gold concentrate that is then transported by road for subsequent shipping to customers. The flotation tailings will be thickened prior to discharge to the tailings management facility (TMF).

The key criteria selected for comminution, flotation, intermediate concentrate regrind and final concentrate and tailings thickening are summarised below:

- Treatment of an average 55,000 dry metric tonnes per day (t/d) for 365 days per year.

- Sufficient plant design flexibility for individual treatment of either of the main ore types tested (whole resource is supergene 47% and hypogene 53%), as tested in the metallurgical test work program, at design throughput.

- Capacity to treat a maximum throughput of 2,915 t/h (63.7 kt/d) and a copper production rate of 20.5 t/h at 91.3% (8000 h/y) availability, based on a maximum head grade of 1.01% Cu.

The concentrator includes the following unit processes and facilities:
- Primary crusher and transfer conveyors
- Crushed ore stockpile and reclaim
- SABC grinding
- Flotation comprising rougher flotation, concentrate regrind, three-stage cleaning and cleaner scavenger flotation
- Concentrate thickening and filtration
- Concentrate storage and load-out
- Tailings thickening and water recycle
- Reagents mixing and distribution (including lime slaking, flotation reagents and flocculants)
- Grinding media storage and addition
- Water services (including raw water, fire water, gland water, cooling water and process water)
- Potable water treatment and distribution
- Air services (including high pressure air and low pressure process air).