A mineral resource update for the Beatons Creek gold project in the Pilbara region of Western Australia, incorporating new drilling data and PhotonAssay techniques.
Report context
This technical report presents an updated Mineral Resource estimate (MRE) for the Beatons Creek gold project, held by Beatons Creek Gold Pty Ltd and, in certain circumstances, beneficially held by Nullagine Gold Pty Ltd, both wholly owned Australian subsidiaries of Novo Resources Corporation. The effective date of the report is June 30, 2022, with an issue date of December 16, 2022. The report supersedes the previous preliminary economic assessment dated effective February 5, 2021. The project is located west of the town of Nullagine in the East Pilbara Shire, Western Australia.
Processing route
Process description
The Golden Eagle processing plant includes a comminution circuit with a single-stage jaw crusher of approximately 400 t/h capacity and a single-stage semi-autogenous grinding (SAG) mill of 6.7 m diameter by 5.65 m effective grinding length with a 4 MW motor and a grinding capacity of 180–190 t/h to 150 µm. Gravity gold recovery is achieved via centrifugal (Knelson) concentration and an intensive cyanidation leach (Acacia) reactor. Leaching occurs in two tanks, followed by seven carbon-in-leach (CIL) tanks, with oxygen addition in the first three leach tanks. Tailings is thickened to 55% solids prior to disposal in a tailings storage facility with return of decant water. Stripping of loaded carbon is in a split AARL column. Gold recovery is via electrowinning cells.
Historical operating data
Between August 2021 and April 2022, three separate fresh bulk processing trials of material from the Grant’s Hill mining area were processed through the Golden Eagle plant. A single fresh trial in August 2021 (Batch #1: 100% Grant’s Hill fresh) was complemented by two additional oxide blended trials in March and April 2022 (Batch #2: 80% and Batch #3: 53% Grant’s Hill fresh). Overall throughputs for the three trials averaged around 207 t/h, approximately 10% less than the recorded oxide throughput. Batch #1 comprised 38,208 t at a reconciled head grade of approximately 1.8 g/t Au yielding approximately 2,034 oz Au, with a recovery of 93.6%. The gravity recovery component during the trial was approximately 56%.
During production, 2.51 Mt of dominantly oxide with some fresh mineralization (approximately 160,000 t), at 1.17 g/t Au was fed to the Golden Eagle processing plant. This contained 94,148 oz Au, with 87,313 oz Au recovered. The global recovery during this period was 92.7%, with 55% recovery from the gravity circuit.
Metallurgical testwork
Six HQ diamond drillholes were drilled in 2018 to provide fresh mineralization samples for testwork on material from Grant’s Hill and South Hill. Comminution testwork showed fresh material is competent, with an average Bond ball mill work index for Grant’s Hill of 18.8 kWh/t. SAG mill comminution test data indicated that the fresh mineralization is moderately competent with an average A*b of 47.8 and a range of 38.0 (hard) to 56.6 (soft). Testwork also showed that the fresh mineralization is abrasive with an average Bond abrasion index value of 0.26. Three-stage gravity recoverable gold (GRG) test recovery was high at 94.6% and 89.0%, respectively, for the M1 and M2 mineralized conglomerate composites. The average 24-hour leach extraction for all six tests on Grant’s Hill samples (regardless of grind size) was 93.3%. The single stage GRG test recovery was 61.3% and 69.8%, respectively, for the South Hill CH1 and CH2 composites. The average 24-hour leach extraction for all six tests on South Hill samples (regardless of grind size) was 60.1%.
Nine HQ diamond holes were drilled in 2022 to provide fresh mineralization samples for metallurgical testwork on Grant’s Hill and Edwards materials. Gravity and kinetic cyanide leach tests were conducted on 23 interval composite samples along with three GRG samples that contained multiple interval samples. A single grind size of P80 -150 µm was used with and without carbon addition. Three-stage GRG tests were conducted on three composites. Composites GRG01–03 returned overall GRG recoveries of 78.3%, 85.4% and 87.6%. Overall gravity and CIL extractions ranged from 56% to 98%, with an average of 87% for a 24-hour leach. The recovery results were weighted by sample representivity (based on MRE tonnages) to generate an overall recovery of 91%.
Key reported parameters
| Parameter | Unit | Design / Estimate | Actual / Testwork |
|---|---|---|---|
| Jaw crusher capacity | t/h | 400 | , |
| SAG mill diameter | m | 6.7 | , |
| SAG mill effective grinding length | m | 5.65 | , |
| SAG mill motor power | MW | 4 | , |
| Grinding capacity (to 150 µm) | t/h | 180–190 | , |
| Average throughput (fresh trials) | t/h | , | ~207 |
| Bond ball mill work index (Grant’s Hill fresh) | kWh/t | , | 18.8 (avg) |
| A*b (Grant’s Hill fresh) | , | , | 47.8 (avg); range 38.0–56.6 |
| Bond abrasion index (fresh) | , | , | 0.26 (avg) |
| Three-stage GRG recovery (M1 composite) | % | , | 94.6 |
| Three-stage GRG recovery (M2 composite) | % | , | 89.0 |
| Three-stage GRG recovery (GRG01–03 composites) | % | , | 78.3, 85.4, 87.6 |
| 24-hour leach extraction (Grant’s Hill) | % | , | 93.3 (avg, 6 tests) |
| 24-hour leach extraction (South Hill) | % | , | 60.1 (avg, 6 tests) |
| Average overall gravity and CIL extraction (2022 testwork) | % | , | 87 |
| Weighted overall fresh recovery (for RPEEE) | % | 91 | , |
| Batch #1 fresh trial recovery | % | , | 93.6 |
| Global production recovery (oxide-dominant, 2021–2022) | % | , | 92.7 |
| Production gravity recovery component | % | , | 55 |
Project website: https://novoresources.com/news/beatons-creek-operational-update/
Technical qualifications
Mineral Resources reported in this technical report are not Mineral Reserves and do not have demonstrated economic viability. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues; however, no issues are known at this time. The quantity and grade of reported Inferred Mineral Resources are uncertain in nature and there has been insufficient exploration to define these Inferred Mineral Resources as an Indicated or Measured Mineral Resource; furthermore, it is uncertain if further exploration will result in upgrading Inferred Mineral Resources to an Indicated or Measured Mineral Resource category.
Key risks for the Fresh Rock Expansion include the extended timeframe required for assessment under Part IV of the EP Act if the Minister for Environment upholds the appeal against the EPA decision not to assess the mining proposal, and demonstrating that potentially acid forming waste rock material will not result in impacts to the Priority 1 Public Drinking Water Supply Area underlying Beatons Creek. The report notes that all PAF waste is proposed to be encapsulated and fresh rock pits backfilled to re-establish pre-existing surface water drainage, requiring the majority of all waste generated to be rehandled.
The QPs consider the PhotonAssay technique suitable for the estimation and classification of Mineral Resources according to the CIM Definition Standards (2014) and associated Best Practice Guidelines (2019). This MRE is one of the first to be estimated based dominantly on samples assayed via the PhotonAssay technique.
*Source: NI 43-101 Technical Report: Mineral Resource Update, Beatons Creek Gold Project, Nullagine, Western Australia, effective June 30, 2022.*
