King River Resources has successfully trialled its streamlined high-purity alumina, or “HPA” processing route, utilising a readily available aluminium feedstock, to create an HPA precursor product. Metallurgical test work is currently underway on both this new precursor and the Speewah precursor to deliver a 4N HPA product at 99.99 per cent pure alumina.
4N HPA is used in a range of emerging technologies from mobile phones and LED lighting to lithium-ion batteries.
The main outcome from King River’s latest test work is that the “KRR processing route” can be used on a variety of feedstocks which will allow a processing facility to established and operate as a stand-alone facility apart from the proposed mining operation at Speewah.
King River is currently looking at the viability of constructing a 4N HPA plant in Perth, where access to infrastructure and resources would reduce the company’s capital and permitting requirements. Such a plant would provide an early path to cash flow, eliminate the need for an acid plant adjacent to the developing Speewah operations and help fund the transition into mining and production at the massive deposit.
Its ongoing metallurgical test work and production planning is part of King River’s feasibility study over its Speewah Dome high purity alumina project in the Kimberley region of Western Australia.
The Speewah Dome project is located 110 kilometres south-west of Kununurra on the eastern margin of the Kimberley. According to King River, the project hosts Australia’s largest vanadiferous titanomagnetite deposit, weighing in at 4.7 billion tonnes at 0.3 per cent vanadium pentoxide, 3.3 per cent titanium oxide and 14.7 per cent iron.
In something of a usual twist, the deposit contains high levels of both alumina and magnesium. The high alumina content, weighing in at around 12.5 per cent, can be used to create high purity alumina, or “HPA” product bringing into focus the production pathway that will likely provide the foundation of the company’s upcoming pre-feasibility study, or “PFS”.
Much of King River’s PFS is now complete with CSA global and Como Engineers having already tabled their respective mining and engineering studies.
The company’s ongoing hydrometallurgical studies have delivered a stream of improvements to the planned HPA processing path. This includes the simplification of the purification circuit to produce an HPA precursor that uses only ‘Crystallisation’. It is a two-phase process with the primary phase involving crystallisation of the feedstock to produce a crude aluminium product. This product is then put through a two-stage recrystallisation process that produces the HPA precursor, with very low impurity levels.
This innovation eliminates the need for a secondary ion exchange circuit and delivers substantial cost savings across the entire mining cycle through improved recoveries and reduced mining and processing rates.
King River has now turned its attention the next stage of the circuit with test work on the calcination of the HPA precursor at 1250 degrees Celsius to create a ‘4N’ HPA product at 99.99 per cent pure alumina.
The company’s metallurgical test work to produce a 4N HPA is entering its final stages. A model is now being developed to build an integrated HPA operation in Western Australia utilising the Speewah operations, and other potential sources, to provide a feedstock to a stand-alone processing plant in Perth.
Ongoing results from King River’s PFS are expected in the coming weeks.
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