Summary

Deposit type

• Vein / narrow vein
• Breccia pipe / Stockwork
• Hydrothermal

Summary:

eenstone Belt, which forms part of the Yilgarn Craton, a 2.7 Ga granite-greenstone terrain in southern Western Australia.

Gold deposits along the Norseman-Wiluna Greenstone Belt are hosted within a diverse range of rocks, including basalts and dolerites, fine to coarse-grained sedimentary rocks, and felsic to intermediate intrusives. Host rocks are commonly metamorphosed to greenschist or lower amphibolite facies. Gold mineralisation is typically structurally controlled, occurring within a network of shear zones proximal to major regional faults. The most important gold mineralisation styles are shear hosted quartz-carbonate bearing breccia lodes and associated quartz vein arrays, together with finely disseminated gold associated with zones of strong hydrothermal alteration. Alteration comprises silica or albite-rich zones, associated with ankerite, sericite, biotite or amphibole, together with pyrite, pyrrhotite or arsenopyrite as sulphide-bearing phases.

The most substantial go

Mining

• Truck & Shovel / Loader
• Sub-level stoping
• Longhole open stoping
• Room-and-pillar

Summary:

o both surface and underground mines.

Open pit
In open pit mining, access to the orebody is achieved by stripping the overburden in benches of fixed height to expose the ore below. This is most typically achieved by drilling and blasting an area, loading the broken rock with excavators into dump trucks and hauling the rock and/or soil to dumps. The overburden material is placed on designated waste rock dumps.

Extraction of the orebody involves a similar activity as in stripping the overburden. Lines are established on the pit floor demarcating ore from waste material and the rock is then drilled and blasted. Post blasting, the ore is loaded into dump trucks, based on a defined ‘dig plan® demarcating the position of the ore and waste boundaries post the heave and throw movement caused by the blasting, and hauled to interim stockpiles or directly to the crusher at the process plant, while the waste is hauled to waste rock dumps.

There has been no open pit mining at Agnew since 2012, but this will change in H2 2022 with Barren Lands Open pit planned to start.

Open pit mining will be by conventional drill and blast, with truck and shovel operations. Overall, the pits represent 4 % of the total reserve ounces for Agnew.

The open pits are seen as a consolidated approximate 12-month duration opportunity to ensure critical mass in mobilizing a contractor to complete all the open pits then de-mobilize. The drill, blast, truck and shovel equipment supplied will be supportive of mining the narrow orebodies with minimum dilution.

The open pits will be sequenced together to optimize the waste strip and expedite the ore to the processing facility. Agnew is not expecting to build significant stockpiles for future processing.

Mining in the Barren Lands open pit was completed in 2023 and portal development for the underground operations commenced.

Underground
For Agnew’s underground mines, access is through single or multiple decline haulages extending from surface portals. Horizontal and decline development at various intervals from the main decline, known as levels, extend laterally and provide access to the ore horizons for mining.

Once an orebody is accessed for mining (or stoping), production activities consisting of drilling, blasting, cleaning, ground support and transporting rock, which are carried out on a daily basis.

Broken ore is loaded straight from the stope face into trucks, using mechanical loaders, and hauled to the surface by underground dump trucks via the declines. Application of backfill or paste fill to the mined-out areas to support the ground is based on local conditions and is not always required in shallow underground mining areas.

Both Waroonga and New Holland are established mines with existing infrastructure. The Redeemer Complex is proximal to the historic underground, and includes establishment of a new portal, surface infrastructure, declines, and underground infrastructure.

Mining operations a

Comminution

Crushers and Mills

Summary:

Crushed product is fed from the fine ore stockpile and ground to 80 % passing 125 um using a two-stage closed circuit primary and secondary ball milling circuit with two overflow type ball mills and 1,200 kW motors.

In 2022, Agnew complete the mill crushing circuit replacement:

The construction of a new crusher was completed. It comprised a 3 Stage crushing plant. Additionally, a fine ore bin was installed for dust management within the crushing area. The mill throughput was increased to 1.4Mtpa, with future-proofing for up to 1.7Mtpa.

Beneficiation

• Gravity separation
• Carbon re-activation kiln
• Centrifugal concentrator
• Crush & Screen plant
• Concentrate leach
• Agitated tank (VAT) leaching
• Inline Leach Reactor (ILR)
• Carbon in pulp (CIP)
• Elution
• Carbon adsorption-desorption-recovery (ADR)
• Solvent Extraction & Electrowinning
• Cyanide (reagent)

Summary:

.35Mtpa capacity).

The plant capacity was increased to 1.35Mtpa at the end of 2022.

The gravity circuit comprises two 40" QS40 Knelson concentrators with dedicated InLine Leach Reactor for intensive cyanidation of the gravity concentrate.

The leach circuit is comprised of three air agitated Pachuca leach tanks each providing an effective volume of 4,100 m3. The adsorption circuit consists of six air agitated Pachuca adsorption tanks with an effective volume of 3,000 m3. Each adsorption tank is fitted with “V" style inter-stage screens and an airlift carbon advance system. Loaded carbon is recovered from the first adsorption tank via a vibrating loaded carbon screen. Loaded carbon from the adsorption circuit reports to the acid wash hopper where it undergoes a hot hydrochloric acid wash.

Acid washed carbon is loaded into a pressure Zadra elution column followed by electrowinning at approximately 130°C and 350 kPa. The elution column has a 3.0 t capacity and one elution is conducted each day. Barren carbon from the elution circuit is regenerated in a carbon regeneration kiln.

Gold sludge from both the gravity and electrowinning circuits is washed and filtered. The sludge is further refined through smelting and crude doré is poured. Gravity doré bars are approximately 90 % to 95 % gold whereas doré bars from the CIP circuit are dependent on ore feed characteristics and can vary between 65 % and 80 % gold. Doré is dispatched to the Perth Mint refinery for further processing into gold bullion.

Pipelines and Water Supply

Summary:

paste plant operations and potable water.

Mine dewatering is reused within the underground mine for dust suppression, the paste plant and to supplement process water. Return water return from the tailings storage facilities is the largest source of water for the process plant. A water supply of up to 4,900 kl/day is required for processing.

Additional water is supplied from the Fairyland borefield (located approximately 22km from the process plant) and the Daisy Queen borefield (located approximately 12km from the process plant), EMU borefield (approximately 2km from process plant) and the former Hidden Secret open pit at New Holland.

The current operation is utilizing 50 percent of the licenced allocation (3,377,980 kl/annum of 6,810,000 kl/annum) across three GWLs. 2 Gl/annum is required for mine make-up water requirements.

Commodity Production

Operational metrics

Personnel

Job Title	Name	Phone	Profile	Ref. Date
General Manager Operations	Craig Bradshaw			Apr 18, 2024
Vice President of Mining	Jason Sander	+61 (0) 8 9088-3801		Apr 18, 2024