King River Resources’ (ASX:KRR) HPA project gathers steam with recent developments

Image Source: Company Website


  • High Purity Alumina has made to the critical minerals’ list of the Australian Federal Government.
  • King River Resources is on a roll with six campaigns demonstrating the production of >5N purity Aluminium Salt Precursor 1 compound.
  • Testwork is advancing further to define a new process route for the production of 4N HPA, which is potentially more economical and environment-friendly.
  • The company plans to continue laboratory testwork to evaluate different scales of 4N HPA production to further reduce the capital and operating costs.

King River Resources Limited (ASX:KRR) is committed to tapping the opportunities associated with the processing of its 5N (99.999%) purity Type 1 Precursor for the battery manufacturing industry. The current focus is on advancing the Company’s Definitive Feasibility Study (DFS) for the Type 1 Precursor Production Plant. Type 1 Precursor is an aluminium salt, which is used in lithium-ion batteries.

The Company continues to explore various routes to develop a process design for the production of 4N category HPA products, which are more economical as well as environment-friendly. HPA is a high-purity form of aluminium oxide (Al2O3) used in the manufacturing of LEDs, semiconductor wafers, scratch-resistant glass, and coating on the separator sheets in lithium-ion batteries. 4N represents the purity level of the product, which is 99.99% in the case of 4N.

Related read: King River Resources’ (ASX:KRR) ‘green’ process flowsheet to focus on speciality metals at Speewah

HPA – A critical mineral witnessing robust demand

High Purity Alumina (HPA) has been included in the list of critical minerals by the Australian federal government. The government has plans to position Australia as a global powerhouse in the critical minerals industry and capitalise on the country’s robust resources sector.

The government has also allocated AU$200 million to the Critical Minerals Accelerator Initiative to support the projects that are strategic in nature and accelerate their development and further investments into such projects.

Moreover, market investigation for 4N HPA end-users has shown rising demand for Australian products.

The Company’s initiatives are well aligned with the government’s initiative and current market trends for the HPA.

Related read: King River Resources (ASX:KRR) repeats high-purity Type 1 precursor results, shares jump

New process route to make 4N HPA

Source Certain International (SCI) is conducting laboratory testwork to define a new process route for manufacturing 4N HPA. SCI is making modifications to the initial process on which the Pre-feasibility Study (PFS) was based. Work is underway to implement and fine-tune the process to re-evaluate the PFS design.

Besides that, KRR is working on the protection of the intellectual property (IP) associated with the newly developed process.

Latest work repeats high purity results

Campaign 6 of the laboratory pilot plant resulted in >99.999% purity for Precursor 1. To date, all the six campaigns have demonstrated production of >5N purity Aluminium Salt Precursor 1 compound.

 SCI used an industrial chemical compound as a feedstock for the production of Type 1 Precursor Aluminium salt product. The salt was produced using the ARC process and assayed using the ICP-MS and ICP-AES methods.  

Related read: King River Resources’ (ASX:KRR) first half marked by major strides at HPA and gold projects

SCI ran four analyses on the Campaign 6 batch to improve the result. The >99.999% purity result is an average of the four repeat assays.

Assay result for Type 1 Precursor from Campaign 6 (Image source: Company update, 19 April 2022)

Next steps

KRR will continue the laboratory testwork and the results will help in evaluating different scales of 4N HPA production. The Company is also looking for ways to further lower capital and operating expenses.

The focus will be on scaling up the DFS plant by applying these advancements to the HPA circuit. The DFS design is based on the findings of the PFS, and the next stage of designing will involve removing equipment and process stages that are not required any longer, making it economical.

Engineering and financial modelling studies are also underway to modify and scale up the Precursor plant design to manufacture 4N purity HPA at a scale appropriate to market demand while minimising CAPEX and OPEX for a viable operation.

Also read: Inside King River Resources’ (ASX:KRR) quest to supercharge gold exploration

KRR shares were trading at AU$0.028 midday on 19 April 2022. The Company has a market cap of AU$46.6 million.



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