• Study shows Scope 1 and Scope 2 CO2 emissions per tonne of HPA from Lake Hope on par or lower than competing processes
  • Impact aims for zero carbon HPA with a renewable energy development scenario
  • Pre-Feasibility Study on schedule to be completed in Q4 this year


Special Report: Impact Minerals says its CO2 emissions will likely be ‘significantly lower’ than incumbent high purity alumina processing.

Scope 1 emissions relate to CO2 produced directly from operations and include the proposed mine, haulage of ore and the processing plant.

Scope 2 emissions relate mostly to CO2 produced from the energy used to power the company’s operations.

This latest study has shown that Impact Minerals’ (ASX:IPT) process would be on par or even much lower than emerging processes, especially under a 100% renewable electrical energy development scenario.


Competitive under two processing scenarios

The low emissions apply to both the Sulphate and Low-Temperature-Leach (LTL) processes that are being considered as part of the Pre-Feasibility Study (PFS) for the project – which is expected to be completed by the end of this year (and will up the company’s stake in the project via an earn in agreement to 80%).

Using the current Western Australian electricity supply, likely emissions are 4.38 tonnes of CO2 per tonne of HPA produced via the Sulphate process and 3.44 tonnes of CO2 per tonne of HPA for the LTL process.

Impact notes that this is competitive with traditional and emerging HPA production methods, with most of the world’s HPA production coming from the refinement of aluminium metal via energy-intensive processes that result in large amounts of toxic waste.

To date, both processes have produced HPA at greater than the benchmark purity of 99.99% (4N), and a key focus of the PFS will be to determine the preferred process as the project moves towards production.


Graph: Likely CO2 emissions for four different production methods for HPA: the incumbent alkoxide process; Alpha HPA, Impact’s proposed Sulphate and Low Temperature-Leach processes; & AEM who produce HPA in Canada using hydroelectric power. Source: IPT.


100% renewable energy on the cards

The largest contributor to the overall CO2 emissions from the project come from Scope 2 emissions from the electricity required to power the processing plant.

This has been modelled to come from the South West Interconnected System (SWIS), Western Australia’s main power source.

The SWIS is currently coal-powered and the emissions from this have been used in the main model, however, the WA Government is committed to making the SWIS entirely powered by renewables by 2030.

The company also believes there’s potential to power the process plant entirely by renewable energy in the future, so the study also modelled the CO2 emissions under a 100% renewable energy scenario.

This resulted in a further reduction in emissions for both processing routes to about 1.35 tonnes of CO2 per tonne of HPA – which would be on par with or better than the lowest known CO2 emissions for HPA production which is powered by hydroelectric power.

Moving forwards, Impact’s strategy for 100% renewable power is to build-out or contract-to-purchase a renewable energy supply for the processing plant.

This will be studied as part of engineering and financial modelling under the PFS.




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.