Reward Minerals Ltd (ASX:RWD) is making progress on an engineering scoping study (ESS) with a new in-house laboratory work program to optimise reaction times of the company’s new potassium sulphate processing technology returning highly encouraging results.
The program has wrapped up, culminating in small-scale production of high-purity potassium sulphate (SOP) with a concentration of 53.7% K2O, 56.8% SO4 and less than 0.1% CI.
High-purity potassium sulphate
The SOP produced has been found to be 99.4% pure, with impurity levels well below typical export quality standards (100% pure SOP contains 54.05% K2O).
These results give Reward the momentum to continue the development of its newly discovered processing technology for the recovery of SOP from seawater and other high-sulphate brines.
Reward CEO Lorry Hughes said: “The results of this round of laboratory test-work have been very positive and we believe that our technical innovation has the potential to transform the company.
“To produce such high-purity SOP using readily available equipment and simplified processes could translate to significant reductions in capital and operating costs for commercial-scale operations.
“Estimates of these costs will be generated as part of the current ESS planned for completion mid-year.”
The process
The recent program aimed to optimise reaction times in the Reward Process to produce high-purity SOP (greater than 52% K2O) from seawater and other high-sulphate brines including Reward’s Kumpupintil Lake Resource brine.
It was a direct follow-up to previous Reward Process test-work, during which a more-than-50% first-pass extraction of K2O to the solid Syngenite salt was achieved from a seawater-derived brine.
For the current program, this brine was used with optimised reaction times and achieved 57% first-pass extraction of K2O to the solid Syngenite salt.
In operations, the residual Syngenite Reactor liquor will be recycled to the brine evaporation ponds for further SOP recovery.
Earlier test-work on the Kumpupintil Lake resource brine indicated the Reward Process method provided a first pass K2O recovery to Syngenite product of around 40%.
Importantly, the 40% recovery figure for brines of composition similar to that of the Kumpupintil Lake resource brine is possible without re-dissolution of pre-crystallised salts.
Satisfied that it has confirmed the robustness of the first order SysCAD Flowsheet and Mass Balance Model compiled in the last quarter of 2022, the company will now conduct an independently verified ESS, scheduled for completion by mid-year.
These results form part of the Australian patent application for the Reward Process. An international patent application is also in the works.
Next steps
Over the next two quarters, Reward will focus on:
- advancement of the Reward Process, international patent finalisation and licensing activities for third parties;
- advancing the ESS for the Kumpupintil Lake Project and seawater derived brines based on the Reward Process;
- engagement with solar salt, fertilizer and seawater desalination companies worldwide to discuss the application of Reward’s technology within proposed SOP developments for possible joint ventures; and
- receipt of results from Fortescue’s RC drilling program at the McKay Range Joint Venture in the northwest of Western Australia.