Bulk Sampling and Test Pit Program Completed at the Lake Hope HPA Project, WA

A significant bulk sampling and test pits program has recently been completed at Impact Minerals Limited’s (ASX:IPT) flagship Lake Hope High Purity Alumina (HPA) project located 500 km east of Perth in Western Australia. The program is a critical component of the Pre-Feasibility Study on Lake Hope, which is currently underway following a positive Scoping Study on the project that indicated the project may be the lowest-cost producer of HPA globally by a significant margin (ASX Release 9th November 2023).

Impact has the right to earn an 80% interest in the Lake Hope project by completing the Pre-feasibility Study (ASX Release 21st March 2023).

A total of 5.5 tonnes of material was collected from twenty-five bulk samples taken from test pits across West Lake and East Lake, which host the alumina deposit at Lake Hope. The deposit contains a resource of 3.5 million tonnes at 25.1% alumina (Al2O3) for a contained 880,000 tonnes of alumina, of which about 88%, or about 775,000 tonnes of alumina, is in the higher confidence Indicated Resource category (ASX Release 19th June 2023).

Impact confirms that no new information exists, and all modifying factors remain the same as at the time of the first publication of the resource.

In addition, earthworks for access tracks and drill pads for water bores for groundwater monitoring were also completed.

Managing Director Dr Mike Jones said: “This bulk sampling program marks another significant milestone in our journey towards the production of High Purity Alumina (HPA) from Lake Hope and caps off a very busy and successful nine months since acquiring the rights for this exceptional project.

In that time, we have completed a maiden resource statement, obtained heritage clearance from the Ngadju First Nations people, completed most of the first phase of metallurgical test work using the unique Playa One sulphate process, and completed a Scoping Study. The results of that study were outstanding and demonstrated the potential of Lake Hope to produce HPA at a cost much less than any other supplier globally, and this has given us the confidence to progress the pre-feasibility study aggressively. The bulk samples will set us up for the forthcoming stages of development, which will include the commissioning of a mini-pilot plant once the initial test work is completed.

Our focus for 2024 will be to complete the PFS, which will include setting up the mini-pilot plant and, in particular, producing HPA in bulk for potential customers and off-take partners. As part of this strategy, we have already started reaching out to key groups in the battery and LED market, and the demand is there. We look forward to a watershed year for Lake Hope, Impact and its shareholders”.

About the Bulk Sampling and Earthworks Program

Impact commissioned Pinnacle Site Services to undertake an earthwork and bulk sampling program. A backhoe was used to refurbish the existing access track to the site, construct access tracks to the lakes and a drill pad for a water monitoring bore.

A total of 5.5 tonnes of aluminous mud was collected from 25 pits, 13 from West Lake and 12 from East Lake (Table 1 and Figure 1). Ground conditions during excavation of the lake surfaces were excellent, with the mud hard, dry and easily dug. Groundwater was absent in most excavations, likely due to the dry summer conditions, which emulate the three-yearly summer mining campaigns proposed in the Scoping Study (ASX Release 9th November 2023).

A number of the sample sites were left open for geotechnical studies on the performance of the mud with respect to slope stability and groundwater levels, both of which will be monitored over the next 12 months before rehabilitation.

These ground-disturbing activities were enabled after successful Aboriginal Culture and Archaeological surveys were completed in July with the Ngadju Native Title group (ASX Release 27th July 2023). The survey identified no sites of cultural or archaeological significance, which is critical for Impact lodging a Mining Lease Application.

Update on the Pre-Feasibility Study

Impact has continued to progress the Preliminary Feasibility Study on Lake Hope.

The Baseline Flora and Fauna Survey data collection process is complete, with a final report due early in Q1 2024. Once received, the results will be used to finalise the location of mining lease boundaries and infrastructure corridors. A Mineralisation Report, a critical requirement of a mining lease application, has been completed, and the application will be lodged as soon as practicable in Q1 2024.

The metallurgical test work has progressed to final purification testing, with preliminary results expected in January 2024 (Stages 4 and 5 of the Playa One Sulphate Process, ASX Release 18th October 2023). Design of the by-product circuit and re-design of acid and reagent handling strategy is underway to investigate options for reduced capital and energy costs. A comprehensive test work regime is under design to inform a mini-pilot plant configuration, with quotes being sought.

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