Better than 99.99% (4N+) high-purity alumina (HPA) has been produced from the metallurgical processing of lake clays from Impact Minerals’ (ASX:IPT) Lake Hope project.
The 4N HPA was produced via a proprietary and patented metallurgical process, called the ‘sulphate process, which is owned by privately held Playa One.
The $34.37 million market capitalisation company says the recent results add further momentum to Impact’s ongoing Prefeasibility Study (PFS) at the Lake Hope Project in Western Australia, which is progressing on schedule and due for completion late this year.
Impact Minerals Managing Director Dr Mike Jones says producing 4N HPA is a ‘major’ milestone and ‘exciting’ results for the company as it has now demonstrated that it can produce this ‘high-value’ product that commands prices of US$20,000 per tonne or more.
As this news service previously reported, the sulphate process underpins the recent Scoping Study, which demonstrates an net present value (NPV8) of $1.3 billion for Lake Hope and an estimated operating cost to produce 4N HPA up to 50% lower than anyone else globally, at less than US$4,000 per tonne.
Jones says: “We have also optimised the Playa One sulphate process and have already started batch production of HPA to demonstrate consistent quality to our potential customers.
We have discovered from our marketing that there is very strong demand for this high-value product, so we will continue progressing the Prefeasibility Study as quickly as possible.
In addition, we recently uncovered 2 other possible process routes to produce HPA from these remarkable clays, which may offer yet further reductions in operating cost and capital expenditure if our initial testwork is positive, and we are looking forward to getting those results soon.”
A full run of all 5 stages of the sulphate process is currently in progress to demonstrate production of HPA in bulk at a consistent purity to satisfy end-user requirements.
As part of the ongoing metallurgical research, Impact Minerals Project Manager and Director of Playa One Roland Gotthard has uncovered other potential pathways to HPA which may offer a simplified low-temperature flowsheet that may ‘significantly’ reduce reagent and energy costs compared to the sulphate process.
Impact says 2 processes are showing promise. Results from initial testwork on one process are due shortly, while the second process is due at the start of Q2 2024.
Further, the company also expects to release a report on the baseline flora and fauna surveys completed in late 2023 this quarter.
A report on the baseline flora and fauna surveys completed in late 2023 is expected in the current quarter. Impact notes that preliminary advice is that minor adjustments to the haul road corridor may be required to avoid sensitive flora communities.
This will not affect mining on the lake, the company adds.
Impact Minerals is a mineral explorer focused on its ‘extensive’ tenement holdings covering a 4,000km-square area within Australia.
The clays at Lake Hope occur in the top 2m of two small salt lakes on E63/2086 in a deposit containing about 880,000 tonnes of alumina (Al2O3) in various minerals. The deposit comprises indicated (88%) and inferred resources (12%) of 3.5 million tonnes at an average grade of 25.1% alumina.
Impact says the lake clays contain a unique combination of naturally extremely fine-grained minerals, which delivers significant cost advantages to the mining and processing of the ore to produce HPA.
The clays are free-digging and require no crushing, screening or other on-site preparation, and it is envisaged that the clay will be trucked offsite to a pre-permitted industrial site, most likely either in Kalgoorlie or Perth.
As of 31 December 2023, the company had $2.098 million cash and cash equivalents at hand, according to its latest quarterly report.
Write to Aaliyah Rogan at Mining.com.au
Images: Impact Minerals
