The Araguaia Project comprises of Araguaia Nickel Project (HZMA) and the Glencore Araguaia Project (GAP). HZMA is centred approximately 07°54’S and 49°26’W. GAP contains the VDS licence and is centred at 7°03’S and 49°21’W.

The target mineralisation at the HZMA and GAP Project is characteristic of typical nickel laterite deposits formed in a seasonally wet tropical climate, on weathered and partially serpentinised ultramafic rocks. Features of nickel laterites include:
1) The nickel is derived from altered olivine, pyroxene and serpentine that constitute the bulk of tectonically emplaced ultramafic oceanic crust and upper mantle rocks.
2) Lateritisation of serpentinised peridotite bodies occurred during the Tertiary period and the residual products have been preserved as laterite profiles over plateaus/amphitheatres, elevated terraces and ridges/spurs.
3) The process of formation starts with hydration, oxidation, and hydrolysis, within the zone of oxidation, of the minerals comprising the ultramafic protore.
4) The warm/hot climate and the circulation of meteoric water (the pH being neutral to acid and the Eh being neutral to oxidant) are essential to this process. Silicates are in part dissolved, and the soluble substances are carried out of the system.
5) This process results in the concentration of nickel in the regolith in hydrated silicate minerals and hydrated iron oxides; nickel and cobalt also concentrate in manganese oxides. The regolith hosting nickel laterite deposits is typically 10 m to 50 m thick, but can exceed 100 m.
6) Concentration of the nickel by leaching from the limonite zone and enrichment in the underlying saprolite zones is also common. Leaching of magnesium +/- silicon causes nickel and iron to become relatively concentrated in the limonite zone. Nickel is released by re-crystallisation and dehydration of iron oxy-hydrides and is slowly leached downwards through the profile, both vertically and laterally, re-precipitating at the base with silicon and magnesium to form an absolute concentration within the saprolite.
7) The degree of the nickel concentration and the detailed type of regolith profile developed is determined by several factors including climate, geomorphology, drainage, lithology composition, and structures in the parent rock, acting over time.
8) A typical laterite profile contains three distinct horizons (limonite, transition and saprolite).

A nickel laterite deposit profile at HZMA typically consists from surface to bedrock of:
* A Soil Horizon – 0.6 m to 1.6 m average thickness.
* Ferricrete Horizon (including unconsolidated and cemented types, iron cap and pisolites) – 0.6 m to 4.3 m average thickness.
* Limonite Horizon (red and yellow types) – 7.5 m to 11.6 m average thickness.
* Transition Horizon (upper plastic, green and brown types depending on the ratio of nontronite, goethite and manganese minerals) – 3.2 m to 6.3 m average thickness.
* Saprolite Horizon (earthy, rocky and silicified types) – 5.2 m to 10 m average thickness.

The lithological facies description for GAP is slightly different to those used for HZMA and include:
- A Soil Horizon – 0.2 m average thickness.
- Ferricrete Horizon (dark brown to red) – formed by aggregated pisolites (iron oxyhydroxides) that are often very hard and porous.
- Limonite Horizon (dark brown, red and yellow types) – comprises loose pisolites, red limonite, yellow limonite, red tapa and orange tapa.
- Upper Saprolite – green tapa converts to orange-brown transitional.
- Lower Saprolite (light green) – comprises green tapa and saprolitic serpentine holding remants of the original rock texture with abundant amorphous silica and iron hydroxides.
- Silicified saprolite and fault zone (white to purple, pink to grey) – contains talc,
silicified saprolite and silcrete.
- Bedrock facies (grey to green to purple tored) – includes friable weathered harzburgite rock with blocks of unweathered hard rock, harzburgite and silexite which is silica rich breccia of green magnetic material.
- Other facies – includes gabbronorite/weathered gabbronorite (brown to yellow), mafic saprolite (yellow-brown) and metasediment (light yellow to grey).

The seven deposits in HZMA are: Vila Oito East (VOE); Vila Oito (VOI); Vila Oito West (VOW); Jacutinga (JAC); Pequizeiro West (PQW); Pequizeiro (PQZ), and Baião (BAI).

The deposits in HZMA are heterogeneous as far as lateritic facies distribution is concerned. The average thickness for the limonite facies ranges from 7.5 m to 11.6 m, while maximum thicknesses vary from 23.9 m to 45.0 m. The saprolite horizon shows similar average variations while the total thickness is highly variable.

Typical limonite facies laterite contains 0.78% Ni, 0.11% Co, 2.4% Cr2O3, less than 2% MgO, 36.5% Fe and 19.7% SiO2. The underlying transition material typically contains 1.20% Ni, 0.05% Co, 11.7% MgO, 18.3% Fe and 44.3% SiO2. The underlying earthyrocky saprolite typically contains 1.29% to 0.92% Ni, 0.04% to 0.03% Co, 18.3% to 27.0% MgO, 14.8% to 9.7% Fe, and 41.8% to 42.2% SiO2.

Jacutinga (JAC), Vila Oito West (VOW), Vila Oito (VOI), and Vila Oito East (VOE), covers an area of approximately 10 km2.

Pequizeiro and Pequizeiro West. Three northwest trending mineralised bodies cover an area of approximately 3 km2 in this area.

A large prominent hill between Pequizeiro (PQZ) and Pequizeiro West (PQW) demarks the intersection of three fault zones. The hill is composed of massive silica with pervasive iron oxide within the fault zones.

The Baiao area contains three separate ultramafic bodies, the largest being Baião, and covers an area of around 8 km2.

A steeply dipping, silica filled fault zone is located along a north-northwest to southsoutheast trending ridge in the north-eastern part of Baião and reaches up to a width of 250 m. The direction of the fault zone changes to west-northwest to east southeast further north of the ridge. A 200 m wide fresh ultramafic outcrop is located within the rupture zone that is constrained between two steep northeast-southwest trending cross-cutting faults.

The western part of Baião is limited by a zone of massive silica and silicified sedimentary rock, almost 1 km wide. Steeply dipping structures trend north-northeast to south-southwest and northeast-southwest trending. These major trends are dislocated by cross-cutting faults. Contrary to the other cross faults in Pequizeiro and northeast of Baião, these are northwest-southeast trending and filled by silica instead of iron-oxide.

The VDS deposit is orientated north-northwest to south-southeast and is approximately 4,000 m long and has an average width of 800 m. The deposit is enclosed on the west side by faults that dip between 30° and 60° to the east. On the east side the deposit is enclosed by meta-sediments.

With the exception of quartz and gibbsite (trace amounts), all other species identified in this study carry nickel. Sixteen nickel-bearing minerals were quantified by EPMA. The richest nickel-bearing species are nickel-serpentine and two variations of asbolane; low manganese asbolane and low nickel-cobalt asbolane. These three species carry an average of 4.8%, 12.0% and 3.5% nickel. However, there is a relatively minor amount of asbolane present. The majority of nickel within VDS is hosted by nickelserpentine, chlorite, iron-montmorillonite, antigorite and oxide species.

Nickel grade drops slightly in very coarse size fractions due to an increase in antigorite content, and a corresponding drop in other species such as chlorite and ironmontmorillonite. Antigorite carries an average of 0.95% Ni, whereas the chlorites and iron-montmorillonites have nickel grades between 1.4% Ni and 1.74% Ni.

Seven mining pits identified for HZMA and one for GAP through a process of pit optimisation using costs, and process recoveries. All eight pits were designed through a standard process of pit optimisation, waste dump design and pit design.

Each of the deposits is proposed to be mined with typical truck and excavator mining.

The proposed process is a single line 0.9 Mt/a RKEF installation, producing approximately 16.4 kt/a nickel as FeNi.

Calcining
The material flowing directly from the dryer to the kiln feed conveyor belt plus when required any reclaimed material from the kiln feed bin will then be combined with reductant coal of <12.5 mm size from the crushed coal storage bin. A weightometer on the ore feed will govern the addition of coal which is controlled by a variable speed rotary valve according to pre-set values and having feedback control to the ore feed rate. It is noted that coal ash is assumed to report to the ore. The kiln feed thus prepared will be conveyed to the kiln feed chute.

The three main physical and chemical processes occurring in the rotary kiln are as follows: drying, calcining and pre-reduction.

The hot calcine at the kiln discharge will pass through a high-temperature screening device for removing any oversize material that may cause blockages in downstream equipment. This will be a trommel with a nominal 60 mm mesh opening (but will include features for a variable setting). Normally it is expected that all or most of the material will pass the trommel. The undersize material will then be discharged into a refractory-lined bin, from where it will be extracted through a transfer chute into a refractory-lined, 15 m 3 container, which will be located on a transfer car. The key equipment associated with the calcine transfer and furnace feed systems are described in a subsequent section.

The kiln off-gas is conveyed to the electrostatic precipitator at approximately 300°C. Collected dust will be pneumatically conveyed to the dust recycling bin at the secondary crushing plant. Clean off-gas will be partially recycled to the coal milling facility to assist drying, and the balance will be discharged to the atmosphere.

The observed dusting rate in the rotary kiln in pilot plant testing was quite low, of the order of 0.5% of kiln feed. Nevertheless, for the purposes of design, a dust rate of 10% of new ore feed (dry basis) will be adopted. As regards kiln temperatures, for the purposes of design, a target temperature of 875°C for the kiln discharge calcine and 850°C for the calcine feed to the furnace will be adopted here. This selection of kiln temperatures allows for good conditions for achieving the required levels of pre-reduction, yet also ensures that the calcine in the kiln will not exceed high temperatures where the onset of sintering could occur.

Smelting
The furnace considered in the present updated PFS is a circular furnace having an 18 m internal hearth diameter for the processing of calcine obtained from treating the HZMA and GAP Project ore at the rate 0.9 Mt/a (dry). Figure 17.7 shows a crosssection of a typical cylindrical electric furnace. Final selection of the furnace design will have to be reviewed in a trade-off study during the next phase of the project, and potentially if required, comparing a circular furnace with a rectangular furnace.

The calcine feed arrangement will include two calcine transfer cars with each car holding two calcine containers. After filling, the calcine transfer car will move to the lifting position, where a dedicated lifting tower (one per car) will lift the container to the top of the furnace feed bins. It has been determined from the energy balance that the specific power consumption is approximately 480 kWh per metric tonne of calcine. On this basis, the required power rating for the furnace will be approximately 49 MW for smelting 102.7 mt/h calcine. This power consumption is calculated based on a slag tapping temperature of 1,550°C and a metal tapping temperature of 1,490°C.

The hot calcine, containing the required level residual reductant from coal introduced with kiln feed, will be temporarily stored in the furnace feed bins, which will be strategically positioned in order to obtain a suitable distribution on side-wall banks of the charge inside the furnace. Hot metal is then transferred to the refining bay. Slag will be tapped via tapholes located approximately diametrically opposite the metal tapholes; tapped slag will be granulated with water and removed to the slag storage area. Any slag fines remaining will settle in an appropriately designed settling tank, and will be reclaimed by front-end loader and also transported to the slag storage area. The required level of side wall cooling in the region of the molten slag layer will be effected by water-cooled copper elements specifically designed for this particular duty.

The various hot calcine discharge transfer points will also have a dedicated (secondary) ventilation system. De-dusted gases collected from the metal and slag tapping locations will be used for cooling the primary off-gas, and then undergo the similar handling steps.

FeNi refining
Crude metal will be tapped at 1,490°C via one of the two tapholes into a preheated ladle. Furnace metal contains trace elements including carbon, phosphorous, silicon and sulphur that are removed during the refining step.

Slag produced by the oxygen-blowing stage will be removed from the surface of the metal by a skimming machine and tilting of the ladle. With the oxidising slag removed, the melt will then be deoxidised with FeSi and aluminium, and a lime-rich basic slag will be formed for the desulphurisation process.

Dissolved oxygen and temperature are key parameters to be controlled and, under favourable conditions, calcium-silicon (CaSi) cored aluminium wire will be injected well into the metal bath to speed up the desulphurisation process. At the end of the cycle, slag will be skimmed off and a metal sample will be taken. Should the analysis match the required specification, the ladle will be submitted to a final heating stage to a temperature of 1,630°C before metal granulation. Should the metal specification not be achieved, a further slag is formed and skimmed off prior to the final heating stage followed by granulation. During the refining process, the oxidising slag will be granulated with water, or allowed to cool naturally, while the reducing slag will be collected and cooled in slag ladles and transferred to a dedicated area. The slower cooling step permits easier breakage of the slag, and facilitates recovery of any entrained metal.

Metal granulation and product conditioning
The ladle containing the refined metal nominally at 1,630°C will be transferred to the granulation facility and will be positioned on a movable platform by the overhead crane. The metal will then be discharged through a sliding gate installed at the bottom of the ladle at a controlled flow rate generally in the range of 1 t/minute to 1.5 t/minute into the first of two water tanks (to contain about half the metal in the ladle), then followed by the second tank containing the balance. The tanks are equipped with strategically located high pressure water nozzles for achieving the correct sizing of the product at the required hot metal flow rate of granulation.

The granulated metal contained in the two holding tanks will then be hoisted by the overhead crane when granulation is complete and transferred to the dewatering bin/screen, and then fed to the rotary dryer. The dried material will then be screened into product sizes as required by the market. The sized material will be bagged or transferred to a stockpile for dispatching. If there are any size fractions of <2 mm, this product is not usually accepted by clients and