• Impact Minerals’ Playa One Sulphate Process successfully produces 4N HPA at Lake Hope
  • Larger scale production will now begin to demonstrate consistent quality to potential customers
  • Two other potential processing routes also being trialled which could reduce capital and operating costs


Special Report: Impact Minerals has used the proprietary and patented Playa One Sulphate Process to produce better than 99.99% (4N) high purity alumina (HPA) using mud sourced from its Lake Hope project in WA.

Lake Hope is unique deposit of clay which contains a resource of 3.5Mt at 25.1% Al2O3 for a contained 880,000t of alumina.

The unique nature of this deposit – such as its size, zero strip ratio, high-grade mineralisation at surface – means no on-site beneficiation is required and the kinetics of the metallurgical process are expected to deliver cost-effective mining and processing.

In fact, Impact Minerals (ASX:IPT) believes Lake Hope could be one of, if not the lowest-cost producers of High Purity Alumina (HPA) globally, possibly by a significant margin of up to 50%.

Its scoping study has estimated an operating cost of US$3,264/t (net of by-product) to produce 10,000tpa 4N HPA over an initial 25-year mine life, well below the Alpha HPA (ASX: A4N) and FYI Resources (ASX: FYI) reported costs of US$5,940/t and US$6,217/t, respectively.

Initial capex for the 10,000tpa operation at Lake Hope is estimated at $253 million. Other key financial metrics include post-tax NPV of $1.334 billion, IRR of 55% and annual cashflow of $174 million.

IPT can earn 80% in Playa One, which owns both the Lake Hope project and the processing technology by completing a pre-feasibility study, which is currently in progress and due for completion in late 2024.


HPA production process proven

The company has now proven that the Playa One Sulphate Process is capable of producing the desired 4N HPA from Lake Hope mud.

Notably, this underpins the scoping study and allows IPT to start producing larger quantities of HPA to demonstrate consistent quality to potential customers.

Preliminary discussions with potential customers have also indicated strong demand for 4N HPA.

While the success of the Playa One Sulphate Process is certainly encouraging, IPT has not put all its eggs into one basket and is exploring other possible routes to produce HPA from Lake Hope that could offer further reductions in operating cost and capital expenditure.

“The production of 4N HPA is a major milestone and exciting result for Impact and its shareholders as we have now shown that we can produce this high-value product, which commands prices of US$20,000 per tonne or more, from the mud in the top two metres of Lake Hope,” IPT managing director Dr Mike Jones said.

“It underpins the results of the scoping study, which showed an NPV8 of $1.3 billion for the project and, at less than US$4,000/t, possibly the lowest cost of production of HPA globally by a significant margin of up to 50%.

“In addition, we recently uncovered two 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 test work is positive, and we are looking forward to getting those results soon.”


Next steps

Besides initial test work on two alternative process routes, IPT also expects to finish in the current quarter with a report on the baseline flora and fauna surveys completed late last year.

Preliminary advice indicates minor adjustments need to be made to the proposed haul road corridor to avoid sensitive flora communities, though it is not expected to affect future mining operations.

Preparation for a mining lease application is also continuing and pending the final flora and fauna report.




This article was developed in collaboration with Impact Minerals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.