Reward Minerals Ltd (ASX:RWD) has welcomed favourable results from its recent engineering scoping study (ESS) which examined the potential for recovering high-purity potassium sulphate (sulphate of potash or SOP) from seawater-derived brines in northwest Western Australia.
Commercially viable
The study, in collaboration with Bechtel Australia Pty Ltd, pointed to the commercial and technological feasibility of recovering 100,000 tonnes per annum (tpa) of SOP using this new processing technology, called the ‘Reward process’.
This study considered sourcing ‘Bitterns’, a byproduct from existing seawater solar salt operations between Carnarvon and Port Hedland.
Bitterns are generally discarded or stockpiled and are in abundant supply – a big bonus for the commercial viability of the project.
Capital expenditure is estimated at A$198.2 million, with an operating cost of around A$273 per tonne SOP.
The ESS serves as a preliminary assessment for Reward to evaluate further technical studies and potential joint ventures with third-party solar salt and SOP companies.
Despite the positive outlook, the company cautions that further evaluations are needed and there is no certainty that the outcomes of the ESS will be achieved. What’s more, future development may require a funding range of A$187-374 million.
Partnerships and patents
The company plans to proceed with a pre-feasibility study (PFS), considering potential partnerships for funding and development.
It has also lodged Australian and international patent applications to protect the technology.
Reward CEO Lorry Hughes had a lot to say about the study which has defined "the world's most ESG-friendly SOP potash project".
“The completion of a world-first evaluation of high-purity SOP production from seawater solar salt reject brines using the Reward Process is another important milestone not only for the company but for some solar salt and SOP producers globally.
“The study was completed with process engineering support from independent engineering group Bechtel under the guidance of Reward’s in-house team of chemical and engineering experts in the very specialised field of SOP brine developments.
“The low estimated operating cost of $301/tonne SOP on a FOB basis reflects the simplicity of the Reward Process and potentially positions the project favourably at the low end of the global cost curve.
“As the Reward Process does not utilise the prohibitively costly and complicated flotation method for separating potassium salts from magnesium salts, the overall capital requirements are competitive compared to existing and developmental flowsheets.
"A significant proportion of the capital cost estimate is required for construction of nearly 500 hectares of lined evaporation ponds.
“We believe there will be opportunities to reduce these costs subject to the specific location, land availability etc.
“The technology can also be adapted to recover high-purity SOP from other high-sulphate brines such as those contained within the company’s KP project.”