Paddington Gold Operations comprises of the following key deposits: Enterprise, Janet Ivy, Bullant, Homestead, Tuart and Federal.

Federal open cut and underground.
The Federal deposit is located 12 km northeast of the Paddington Mill, situated within the Golden Cities camp area.

Mineralisation is hosted by granitoid lithologies and is controlled by a northwest trending fault zone. Gold mineralisation is associated with pyritic vein quartz, with vein density the dominant control on gold grade. Several plunging high-grade lodes within the broader lower grade mineralised envelope are interpreted, and future work will review the potential to extend these lodes.

Enterprise open pit and underground.
The Enterprise deposit is hosted by units of the Enterprise dolerite sill and comprises a breccia cap with underlying quartz stock work. Eight layers have been identified within the sill and identified as Unit 1 to Unit 8 (from depth to surface).

Gold mineralisation is characterised by multiple fault orientations, with the major ore envelope controlled by the intersection of a series of steep trending faults. High-grade gold zones are concentrated in steeply plunging linear zones that coincide with these brittle- ductile faults, and large areas of relatively lower grade mineralisation fill the gaps between the faults.

Homestead Underground.
The Homestead orebody comprises several mineralised high-grade veins (VN01, VN02 and VN03), within the north trending, steep, west- dipping Homestead shear zone. A series of oblique east-west to northwest trending veins, the Phantom and small 140 veins respectively, occur immediately east of the Homestead shear zone. At the northern limit of VN01, the Homestead shear zone is cut by a northeast trending fault structure which laterally offsets the main mineralised zone some 40 m to the west of VN01, which is referred to as VN03.

Two areas have been drill tested during the period, namely depth extensions of the Black Flag West Vein and a newly defined mineralised vein now called the Henning Vein.

The Henning Lode or Vein is a new discovery located in the footwall of the northwest trending, northeast dipping Black Flag West Vein. Orientation of the new vein is interpreted to be north-south trending and steep east dipping. The Henning Vein is characterised by massive to laminated vein quartz with a pyrite/pyrrhotite/galena/sphalerite sulphide assemblage, similar to other mineralised veins in the area. The vein averages approximately 1 m to 2 m in true width based on current data. Mineralisation has been intersected over a strike extent of 50 m to 100 m, and a dip extent of up to 150 m.

Tuart Open Cut and Underground Prospect.
The Tuart Prospect is located within the Mt Pleasant mine camp area, adjacent to the currently operating Homestead underground mine and the previously mined Green Gum open cut mine.

The Tuart deposit comprises a series of high grade quartz-carbonate-sulphide brecciated or laminated veins hosted within mafic volcanics. Supergene oxide mineralisation is developed in the regolith immediately above and/or adjacent to the primary veins. Mineralisation covers a broad area located to the northwest of the Homestead underground mine, and immediately west of the historically mined Quarters open pit and underground mine.

Janet Ivy.
Janet Ivy is located 33 km south of the Paddington Mill and 10 km west of Kalgoorlie, and was an open cut mine that delivered base- load ore to the mill by a dedicated haul road between 2011 and 2013. The deposit is a broad, strike extensive zone of mineralisation contained within felsic porphyry intrusive. Mineralisation is controlled by a vein stock work zone, individual fault-controlled veins, and pervasive wall rock alteration of the porphyry. Significant mineralisation extends over a 1.3 km strike extent and to an average vertical depth of 130 m to 150 m from surface, and remains open along strike and at depth.

Bullant underground.
The Bullant Project is located 40 km west of the Paddington Mill and was acquired from KMC during 2013. The underground mine is situated along the Zuleika Shear Zone, a highly prospective regional north-northwest trending structure. The Shear Zone is a broad ductile to brittle structural corridor contained within a mafic unit in the mine area. The Shear Zone dips sub-vertically to steep east dipping. Mineralisation occurs in up to four lodes (labelled the Main, East, West and Cross lodes) and is associated with biotitesilica-pyrite altered basalt and minor local quartz veining. Both the Main and East lodes remain open at depth and in various other positions around previously mined areas.

The largest producing mines in the Paddington tenement package include the Enterprise open pit, Homestead underground and Bullant underground mines:
- Enterprise mine (Ora Banda Project) currently supplies the majority of the ore processed at the Paddington Mill and is supplemented by the small Wattlebird open pit mine, which commenced mining in mid-2014.
- Homestead underground mine (Mount Pleasant Project) includes the Black Flag West Vein which has been material in boosting mine grade and volume.
- Bullant underground mine, acquired through Norton’s takeover of KMC in April 2013.

Enterprise.
There is a conceptual Stage 4 pit, based on a higher gold price, and a conceptual underground project. The orebody is a south plunging (30° to 225°) brittle stock work in dolerite, fault bound to the north and south east-west trending faults. There is little oxide development and the mineralisation is bound at its upper surface by a very hard silicified sedimentary cap, which has impeded stripping in this area and precludes gravity-caving methods for any underground mine.

The geometry of the deposit results in extensive stripping before the orebody is intersected and an uneven ore production chedule.

The pit runs two fleets of trucks, a fleet of CAT793’s serviced by an EX3600 for waste stripping and a fleet of CAT 777’s serviced by an EX1900 for production.

Wattlebird.
The Wattlebird pit operation is in the Bullant area near the Bullant underground mine and shares some facilities with that operation.

The mineralisation comprises mineralised quartz veins developed in sheared pillow basalt between two ultramafic units. The mine was originally designed as a two-phase development, but a wall failure along a 40 degree dipping fracture (joint) on the haul road forced a rescheduling and redesign of Phase 2 to maintain production while recovering the Phase 1 section of the pit sterilised by the slip.

Mining is undertaken by a dry-hired fleet of CAT777 trucks serviced by an EX1600, with an anticipated move to smaller articulated trucks in the final months of the operation.

Homestead underground mine.
Homestead has historically exploited a shear system developed in basalt, mined on nominal 15 m levels using a derivative of the Avoca method and cemented waste fill. The waste filling technique is novel and involves cement being mixed at the tipping point in a loader bucket allowing rapid turnaround of stopes. The mineralisation occurs in shoots and appears to have a rheological and lithological control related to the iron content of the basalt, resulting in a “spotty dog” grade distribution.

Mine access is via a common portal, servicing a twin decline, one decline devoted to ventilation. The historically mined levels have exploited the steeply easterly dipping (85°) northern VN03 system and the southern VN01 system, the shear striking around 010°. This system is expected to continue down plunge. The Black Flag Vein occurs as a moderately dipping (65°) splay striking 100°, to the east of VN01/VN03 and Henning Lodes as a further ladder-vein developed on a shear splay to Black Flag, striking around 120°.

Bullant.
The Bullant mine was acquired from KMC in 2013 and has subsequently been extensively redeveloped by Norton. Mineralisation is developed in a biotite altered shear in basalt and is exploited to 600 m depth at 18 m to 23 m level intervals using similar methods to that at Homestead, with the variance being that Bullant utilises upholes rather than downholes.

The Paddington Mill uses conventional crushing and grinding (open circuit SABC); cyanide leaching, CIP adsorption, Zadra elution, gravity concentration gold recovery (with a Knelson concentrator and Acacia intensive leaching reactor), electrowinning and smelting.

Ore is delivered to the Paddington run of mine (“ROM”) pad by contract haulage, where it is arranged on source-specific fingers. ROM material is fed to a gyratory crusher (Allis Chalmers 42” x 65”, 300 kW, crusher gap 110 mm closed setting), in order to reduce the ore particle size to a P80 of approximately 120 mm. The capacity of the crusher is up to 1,000 tonnes per hour (“tph”) and operates for only 16 hours or less per day. The crushed ore is stockpiled on a 30,000 t capacity (8,000 t live capacity) stockpile.

Ore and quick lime added to the ore conveyor is fed to the SAG mill at a rate of 350 tph to 480 tph. The SAG mill (Morgardshammer, 8.0 m x 3.95 m, 3.8 MW, fixed speed) uses 125 mm diameter balls as grinding media at an average 10% to 12% charge volume. Water is added to the mill to keep a charge density of 60% to 85%. The SAG mill discharge screen size is 8 mm. The -8 mm stream is diverted to a cluster of cyclones. Material at +8 mm from the SAG mill discharge screen is sent to a pebble crusher (Hydrocone H6000 Pebble Crusher, nominal gap 8 mm to 12 mm) at a feed rate of 40 tph to 90 tph. The P80 of the feed to the pebble crusher is approximately 60 mm while the P80 of the pebble crusher product is 15 mm to 20 mm. The pebble crusher product is fed back to the SAG mill.

The grinding circuit has a cluster of 14, 500 mm Cavex Cyclones (130 mm polyurethane vortex, 102 mm ceramic spigot). Eight of these cyclones are used at any one time. The cyclone feed rate is 1,600 m3/h to 2,000 m3/h and the feed densities are nominally 60%. The operational pressure is 180 kPa to 200 kPa. Cyclone overflow and underflow densities are 33% to 37% and 74% to 78% respectively.

The cyclone overflow is fed to a ball mill (rubber lined Marcy ball mill, 5.03 x 8.50, 3.8 MW, fixed speed). Density of the charge is kept at 74% to 78% by water addition. Balls (65 mm diameter) and recycled SAG mill balls are used as the grinding media, whose levels are kept at around 33% of charge volume. The size of the ore is reduced to a P80 of less than 106 µm. The ball mill discharge trommel screen size is 10 mm.

Fine gold not recovered by gravity is leached in an alkaline cyanide solution. The feed slurry is thickened to 50% to 52% solids in a 30 m high rate pre-leach thickener. The cyanide concentration is maintained at around 200 mg/L to 300 mg/L and the dissolved oxygen at 10 mg/L to 20 mg/L. Oxygen is produced by a 3 tonnes per day (“tpd”) pressure swing oxygen plant. The leach circuit has one leach tank with 6 hours of residence time and three carbon in leach (“CIL”) tanks with 18 hours of residence time.

After leaching and CIL, the slurry is pumped to two parallel trains of five smaller CIP tanks (360 m3 each), which are used purely for carbon adsorption. The carbon concentration in the tanks is kept at 8 g/l to 12 g/l, with a total residence time of around 6 hours to 8 hours per train. The total carbon residence time is approximately 10 days and the average carbon loading is 1,000 g/t Au. The total carbon inventory is 130 tonnes to 150 tonnes.

Two batch Zadra pressure elution circuits each capable of processing 7 t of carbon per day are used in the elution stage. Carbon is initially soaked in cold 3% to 4% hydrochloric acid (HCl) solution for the removal of cations. The elution circuits run at a temperature of 135°C and a pressure of 400 kPa. The elution solution is made up of 3% caustic and 1% cyanide. The residence time in the elution stage is 18 hours. The barren solution from the elution has less than 20 mg/L gold, whereas the barren carbon has less than 80 g/t gold.

Barren carbon is regenerated in a 500 kg/hr horizontal kiln (Ansac) at 680°C to 700°C. Regenerated carbon is sent to the last tank in the CIP.

There are four electrowinning cells. One of the cells is used for electrowinning of gold from the Acacia reactor pregnant leach solution, while the remaining three cells (currently only two cells) are used in the electrowinning of gold from the elution stage loaded solution.

Electrowinning sludge is dried and then smelted into doré bars containing approximately 65% to 90% gold and 9% to 25% silver. These bars are transported to the Perth Mint Refinery to be refined to a purity of 99.99% gold.