The Kundana Operation hosts several deposits spatially associated with the Zuleika Shear Zone (‘ZSZ’), a NW/SE trending structure stretching more than 250km, separating the Ora Banda and Coolgardie Domains.

Typically, deposits within the ‘ZSZ’ are comprised of narrow, high grade quartz veins, hosted within smaller shear structures formed at the contacts of the Archaean Greenstone stratigraphy’s belonging to the two domains.

Strike extents for each of the deposits are controlled by late-stage NNE trending sub-vertical structures, exhibiting varying amounts of dextral offset.

In total, the Kundana area is known to host more than 5Moz of gold, including the deposits Raleigh, Rubicon, Hornet and Pegasus.

The Raleigh deposit is hosted within the Strzelecki Shear, located at the stratigraphic contact between Andesite/Intermediate Volcanoclastic and Gabbro, with varying amounts of interflow sediment.

The main lode comprises a laminated quartz vein up to 2m true width and dipping 70º west, grading on average 55gpt Au. Gold is typically associated with sphalerite and galena.

The deposit is well defined with drilling showing economic mineralisation extending up to 750m below surface.

The Rubicon, Hornet and Pegasus deposits are all hosted within the K2 Shear, located at the stratigraphic contact between Intermediate Volcanoclastic and the Victorious Basalt, with varying amounts of Centenary Shale.

The main lode comprises several mineralising events which can be distinguished by the presence of laminated or brecciated quartz, and differing amounts of galena, sphalerite, arsenopyrite and pyrrhotite.

Vein grades typically average 25gpt Au for the main lode with the structure varying in thickness from 0.5-4m and dipping 80º west. Several hangingwall lodes with varying orientation have also been identified and exhibit localised ore grades.

All three deposits remain open at depth, with drilling and underground development identifying distinct highgrade zones plunging to both the north and south.

Kundana employs the method of underhand long hole bench stoping with paste fill. This method is used to ensure that high extraction rates of the orebody are achieved as the orebody can grade from 5.0gpt to +31gpt plus. This mining method also assists with minimising any future stress impact on the Operation.

Ore drives are mined along the strike of the orebody following the high grade laminated quartz vein. Once the strike ore drive is completed a vertical rise is established and extraction of the ore between two levels is commenced. The ore body is significantly narrower than the Kanowna Belle ore body with stope widths typically in the order of 1.0m to 2.5m wide. Once a stope panel has been mined, typically 15-18m along strike a paste fill barricade is erected and the stope void is backfilled with paste fill (reconstituted mine tailings, sand, cement and water). The paste fill is reticulated from surface via steel pipe work and delivered in to the stope as a thick slurry. Over a period of 1-2 days the paste fill cures and hardens which then allows the next stope void to be extracted. This process continues until the entire level has been mined out.

All mining operations are operated by Northern Star Mining Services.

The crushing circuit is a simple single stage circuit with a 240t capacity ROM bin feeding a Jaques double toggle 60x48 (185kw) crusher at a 420tph crushing capacity. The crushed ore, nominally minus 125mm reports to a 20,000t partially-covered coarse ore stockpile with a live capacity of about 1,000t.

This product is then reclaimed by an apron feeder and two vibrating feeders located under the stockpile and discharged onto a conveyor belt. The crushed ore is then conveyed to the grinding circuit.

The grinding circuit comprises an ANI Products 7.32m x 3.35m SAG mill operating in closed circuit with a Metso Nordberg HP200 recycle cone crusher and an ANI Products 4.72m x 7.01m Ball mill in closed circuit with cyclones. The SAG mill has a grate discharge and is steel lined, while the Ball mill has a trommel screen discharge and is rubber lined. The SAG mill has a variable speed drive with a range of 10 to 12 rpm, while the Ball mill has a fixed speed drive at 14.0 rev/min (72% of critical). The installed power for the SAG and Ball mills is 2,850kW. The grinding circuit throughput is currently around 240 – 250tph.

Pre-leach classification is achieved using a hydro-cyclone classifier circuit consisting of a cluster of 18 x 250mm cyclones that are fed from a central distributor. Only eight to nine of the cyclones are operated at any one time depending on volume of slurry in the milling circuit. Three of the cyclones in the cluster are dedicated to feed the Knelson gravity concentrator during the free milling ore campaigns. The cyclones are operated at a feed pressure of 110-130kpa.

For the free milling ore, the cyclone overflow stream reports directly (via a vibrating trash creen) to a 17m diameter high rate thickener.

The Kanowna Belle processing plant is a complex and versatile plant that includes separate circuits for processing free-milling and refractory gold ores. The processing plant treats ores from both the Kundana and Kanowna Belle Operations through separate processing circuits and produces gold bullion as the final product for both ore types. All of the Kundana mines yield a “free-milling” ore, where the gold is readily available and recoverable in a conventional CIP circuit.

The thickened slurry is pumped to the leaching and adsorption circuit where the recoverable gold is extracted by cyanidation. The cyanidation circuit is a traditional CIP circuit that consists of three leach tanks and six subsequent adsorption tanks. Oxygen is injected into the first two leach tanks by injection down the agitator shaft and also by injection into a Multimix Injector system installed within a pumped, recirculating slurry stream. Oxygen is injected into the third leaching tank via a single ox ........