This technical report presents mineral processing and recovery methods for the Higginsville-Beta Hunt operation in the Eastern Goldfields of Western Australia, as of December 31, 2020.
Report context
This NI 43-101 technical report is dated January 29, 2021, with an effective date of December 31, 2020, prepared for Karora Resources Inc. The operation comprises the Beta Hunt mine, the Higginsville Gold Operations, and the Mt Henry Project, all located in the Eastern Goldfields of Western Australia.
Processing route
Process description
The processing facility at the Higginsville Gold Operation employs a conventional gold recovery circuit comprising crushing, grinding, gravity and intensive cyanidation, leaching and adsorption, carbon stripping, electro-winning, refining, and carbon regeneration. Tailings disposal completes the process.
Crushing and grinding
The process begins with a crushing stage followed by grinding. No further flowsheet details regarding specific crusher types, grinding mill dimensions, or circuit configurations are provided in this section.
Gravity and intensive cyanidation
A gravity concentration circuit is incorporated, with intensive cyanidation applied to gravity concentrates. No further performance data or design specifications are reported.
Leaching and adsorption
The ground material proceeds to leaching and adsorption stages for gold recovery from solution.
Carbon stripping, electro-winning, refining, and carbon regeneration
Loaded carbon is stripped of gold, which is then recovered via electro-winning and refined. Carbon is regenerated for reuse in the adsorption circuit.
Tailings disposal
Tailings from the process are disposed of to a tailings storage facility. No design or performance details for the tailings storage facility are provided.
Plant services
Supporting plant services are included in the process facility but are not described in detail.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Gold recovery | Reported as plant performance data | Historical operating data |
Project website: https://www.westgold.com.au/gold-operations/southern-goldfields/beta-hunt
*Note: No specific recovery percentage values are provided in the cited source material. The report notes gold recoveries are discussed in Section 17.2.1 but does not present numerical recovery data in the available text.*
Technical qualifications
This report is based solely on the original technical report markdown evidence provided. The following limitations apply:
- No flowsheet details, performance specifications, economics, ownership information beyond the named company, current operational status, or external links are available from the source material.
- The mineral processing section (Section 17) describes the process route but does not provide detailed design parameters, equipment specifications, or numerical performance targets.
- Historical operating data for plant performance is referenced as Section 17.2.1 but no numerical values are included in the report.
- Testwork data is not presented in the processing sections of the provided evidence.
- This is a single point-in-time report with an effective date of December 31, 2020, and does not represent current operational status.
Source: NI 43-101 Technical Report, Higginsville-Beta Hunt Operation, Eastern Goldfields, Western Australia, Report Date: January 29, 2021, Effective Date: December 31, 2020, Sections 17.1-17.2.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here in October 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
Beta Hunt Mine — 2019 Preliminary Economic Assessment
Beta Hunt Mine — 2019 Preliminary Economic Assessment
| Company | RNC |
| Date | 2019 |
| Region | Kambalda, Western Australia |
| Commodities | Gold, Nickel |
| Mine Type | Open Pit |
| Throughput | 1.3 Mtpa |
| Status | Operating |
Executive Summary
This Preliminary Economic Assessment outlines the recovery methods for the Beta Hunt Mine, operated by RNC. Historically, the mine utilized toll milling through third-party facilities in the Kambalda region. In June 2019, RNC acquired the Higginsville Gold Operation, which includes a 1.3 Mtpa gold mill and associated infrastructure. Since this acquisition, all gold mineralization from Beta Hunt is processed through the Higginsville Mill, located approximately 80km from the mine site.
The gold processing circuit at Higginsville is a conventional Carbon-in-Leach (CIL) system featuring quaternary crushing and ball milling. A gravity recovery circuit utilizing a Knelson concentrator and Acacia high intensity leach reactor treats the cyclone underflow separately to produce bullion. The overflow from the mill cyclones proceeds to the leach circuit, where pregnant solution is treated via carbon adsorption, acid wash, elution, and electrowinning before smelting.
Nickel mineralization continues to be processed via toll milling agreements with BHP at either the Kambalda Nickel Mill or the Leinster Mill. These facilities use conventional flotation style nickel concentrators. While the original agreement with BHP allowed processing until 2023, recent amendments have been required to accommodate processing at the Leinster Mill due to the Kambalda Nickel Concentrator being on care and maintenance. Tailings are currently deposited in the exhausted Fairplay East open pit, with plans to transfer to alternate open pits or a four paddock tailings storage facility.
Website: https://en.wikipedia.org/wiki/Beta_Hunt_Mine
Report Date: 2019
Region: Kambalda, Western Australia
Project Status: Operating
Commodity: Gold, Nickel
Throughput: 1.3 Mtpa
Mine Life:
Mine Type: Open Pit
Ore type:
Western Australia Operations – Eastern Goldfields — 2020 Technical Report
Western Australia Operations – Eastern Goldfields — 2020 Technical Report
| Company | RNC |
| Date | February 2020 |
| Region | Kambalda, Western Australia |
| Commodities | Gold, Nickel |
Executive Summary
This technical report outlines the recovery methods for the Beta Hunt project located in the Kambalda region of Western Australia. Historically, gold mineralization from Beta Hunt was toll milled through various third-party mills. However, in June 2019, RNC purchased the Higginsville Gold Operation, which includes a 1.3Mtpa gold mill, infrastructure, and a tailings storage facility. Since this acquisition, all Beta Hunt gold mineralization is processed through the Higginsville Mill.
Nickel mineralization is processed differently, purchased and processed by BHP at either the Kambalda Nickel Mill or the Leinster Mill. These facilities utilize conventional flotation style nickel concentrators. The agreement with BHP allows for processing until 2023, with recent amendments allowing processing at the Leinster Mill after the Kambalda Nickel Concentrator was placed on care and maintenance.
Processing Overview
- Gold Processing: Toll milling historically; currently at Higginsville Mill (1.3Mtpa).
- Nickel Processing: Flotation at Kambalda or Leinster Mills via BHP.
- Smelting: Kalgoorlie Nickel Smelter (historical), Leinster Mill (recent).
Website: https://www.juniorminingnetwork.com/junior-miner-news/press-releases/674-tsx/krr/72918-rnc-minerals-announces-filing-of-ni-43-101-technical-report-for-previously-announced-beta-hunt-gold-mineral-reserve.html
Report Date: February 2020
Region: Kambalda, Western Australia
Project Status:
Commodity: Gold, Nickel
Throughput:
Mine Life:
Mine Type:
Ore type:
Lakewood Mill at Kalgoorlie Treats Beta Hunt Ore Through Gravity and CIL
Karora's 2024 technical report on its Higginsville-Lakewood operation describes the 1.0 Mtpa Lakewood plant, bought in 2022, with contract crushing, a ball mill with twin Knelson concentrators and a leach-CIL train.
The Lakewood mill is an operating gold processing plant at Kalgoorlie in the Eastern Goldfields of Western Australia, about 65 km north of the Beta Hunt underground mine. Karora Resources Inc. bought the 1.0 Mtpa mill in July 2022. It became one half of Karora's Higginsville-Lakewood operation, alongside the 1.6 Mtpa Higginsville mill about 80 km south of Beta Hunt. The technical report, effective September 30, 2023 and dated January 4, 2024, updates resources and reserves for the operation and describes both mills. At Lakewood, toll treatment campaigns had declined because Beta Hunt ore kept the plant supplied, and throughput held at about 115 t/h while ramp-up projects continued.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Lakewood mill capacity | 1.0 | Mtpa | Conventional CIL plant |
| Throughput | About 115 | t/h | Consistent, ramp-up ongoing |
| Crushed product size | 10 | mm P80 | Contract mobile crushing |
| Trommel aperture | 16 | mm | Removes scats and reject balls |
| Trash screen aperture | 0.80 | mm | 1.5 m x 3.6 m |
| Gravity screen aperture | 3.25 | mm | Two screens |
| Gravity concentrators | 2 | Not applicable | Knelson XD30 |
| Leach tank | 1,546 | m3 | 12.8 hours design residence |
| CIL tanks | 7 | Not applicable | 2,337 m3 total, 20 hours |
| Leach pH target | 9.6 | Not applicable | Cyanide up to 260 ppm |
| Carbon kiln temperature | About 700 | °C | LNG fired |
| Gold recovery since January 2022 | 91.4 to 95.7 | % | Average 93.8% |
| Average reconciled head grade | 1.76 | g/t Au | Head grade 1.76 to 2.26 g/t |
| Average tails grade | 0.15 | g/t Au | Lakewood |
Overview
Lakewood is a conventional carbon-in-leach (CIL) plant. A crushing contractor reduces the ore to 10 mm. A grate discharge ball mill in closed circuit with cyclones grinds it, and two Knelson concentrators take gravity gold from the cyclone underflow for intensive cyanidation in an Acacia reactor. The mill product is screened for trash and leached in one oxygenated tank before passing through seven CIL tanks. Loaded carbon is stripped by pressure Zadra electrowinning, and both the Zadra and Acacia gold are smelted to bullion in the gold room. Tailings pass a screen and are pumped to the tailings storage facility.
Beta Hunt ore reaches Lakewood by truck. It is classified and stockpiled by grade but is not usually blended.
Key Process Stages
Crushing
Oversize on the ROM pad is broken with a loader or excavator, and a rock breaker handles anything too large for the primary grizzly. The contractor runs mobile jaw and cone crushers and screens to produce a 10 mm product, which a radial stacker places on the ground. A front-end loader feeds the crushed ore through a belt feeder to the mill feed conveyor, and a Ramsey belt scale measures the tonnage.
Grinding and classification
Crushed ore, process water and cyclone underflow enter the ball mill feed chute. The mill runs in closed circuit with a hydrocyclone cluster. A 16 mm trommel on the discharge trunnion removes oversize ore and reject balls, which go to a scats bin, protecting the cyclone feed pumps and reducing wear on cyclones and slurry equipment. Cyclone overflow passes a 1.5 m by 3.6 m trash screen with 0.80 mm openings to remove oversize particles and plastic before leaching.
Gravity and intensive cyanidation
Cyclone underflow is screened on two gravity feed screens at 3.25 mm. Oversize returns to the cyclone feed hopper. Undersize feeds two Knelson XD30 concentrators, which run all the time. Their concentrate goes to a ConSep Acacia CS1000DM intensive dissolution module, and the pregnant solution is electrowon in a ConSep CS1000EW cell in the gold room.
Leaching and adsorption
The leach train has one 1,546 m3 leach tank followed by seven CIL tanks of 2,337 m3 combined. All tanks have dual down-pumping impellers on 55 kW drives. Oxygen can be injected into the first three tanks, with a high shear injector pump recirculating into Tank 1, which takes the first cyanide dose. Cyanide at 30% strength is added through a flow meter and control valve to the leach feed box or the first CIL tank. Design residence is 12.8 hours in leach and 20 hours in adsorption, at a pH target of 9.6 and up to 260 ppm cyanide. Haycarb activated carbon moves counter-current from the last tank to the first, and loaded carbon is pumped from the first CIL tank to elution.
Elution, refining and regeneration
Pressure Zadra elution strips the carbon, and electrowinning plates the gold onto steel wool cathodes. The cathodes are washed, and the gold concentrate is dried and smelted to bullion. Acacia gold is recovered and smelted in the same way. An LNG-fired horizontal kiln reactivates the barren carbon at about 700 °C before it returns to the circuit.
Tailings and services
Slurry from the last CIL tank passes a 0.8 mm tailings screen. Trash and carbon fines go to a self-draining bin, and the undersize is pumped through a polyethylene line to the tailings facility. The Citect control system watches line pressure for blockages or pipe failure. Process water is a mix of bore water, Lakewood tailings return water and water from Kalgoorlie Consolidated Gold Mines. Clean water and potable water are trucked in from Kalgoorlie, and power comes from the local grid.
Additional Interesting Data and Summary
Lakewood recovered between 91.4% and 95.7% of the gold from January 2022, averaging 93.8%. Reconciled and assayed head grades differed by less than 5%, and tails averaged 0.15 g/t gold.
The Higginsville mill, built in 2007 and commissioned in 2008, uses a similar flowsheet. It has four crushing stages, a 4.90 m by 6.77 m overflow ball mill, a Knelson XD40, one leach tank and six 1,000 m3 CIL tanks. It treats open pit ore from around Higginsville together with Beta Hunt underground ore. Its recovery also averaged 93.8% over the same period, at a reconciled head grade of 2.47 g/t.
Key Processes
- Contract mobile crushing to 10 mm
- Ball milling in closed circuit with cyclones and a 16 mm trommel
- Twin Knelson gravity concentration with Acacia intensive cyanidation
- Oxygen-assisted cyanide leaching in one tank
- Counter-current carbon adsorption in seven CIL tanks
- Pressure Zadra elution and electrowinning
- LNG-fired carbon reactivation
- Tailings screening and pipeline disposal
Source: NI 43-101 Technical Report, Higginsville – Lakewood Operation, Eastern Goldfields, Western Australia, September 30, 2023.
Project website: Lakewood Mill
