Reward Minerals Limited (ASX: RWD) has received highly positive results from the latest laboratory work programme to optimise reaction times of specific technical stages of Reward’s new Potassium Sulphate processing technology.
An Engineering Scoping Study (ESS) progress update and new in-house laboratory work programme supported by an independent engineering firm and an external laboratory for check qualitative analyses.
The results provide Reward with strong encouragement to continue development of its newly discovered processing technology for the recovery of Potassium Sulphate (K2SO4 or SOP) from seawater and other high-sulphate brines.
The results of this round of laboratory testwork have been very positive and we believe that our technical innovation has the potential to transform the company,” CEO, Lorry Hughes, said.
“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 recent programme aimed to optimise reaction times of critical unit operations in the Reward Process to produce high-purity SOP (>52% K2O) from seawater and other high-sulphate brines including Reward’s Kumpupintil Lake (KP Lake) Resource brine.
It was a direct follow-up to previous Reward Process testwork whereby +50% first pass extraction of K to the solid Syngenite salt [K2Ca(SO4)2.H2O)] was achieved from a seawater derived brine of composition (11.5g/l K, 350g/l TDS, 1.26 SG)2.
For the current programme, this brine was used with optimised reaction times and achieved 57% first pass extraction of K to the solid Syngenite salt. In operations the residual Syngenite Reactor liquor will be recycled to the brine evaporation ponds for further SOP recovery.
A portion of the Syngenite was then leached with water. The filtrate was evaporated to produce high-purity SOP crystal product, with composition (53.7% K2O, 56.8% SO4, 0.1% Ca and <0.1% Cl). The SOP produced is very high quality (99.4% pure) with impurity levels well below typical export quality products.
Earlier testwork conducted on the KP Lake Resource brine indicated that following evaporation of Resource brine to K saturation point of (ca. 45g/l K) treatment with Gypsum via the Reward Process method provided a first pass K recovery to Syngenite product of around 40%. Importantly, the 40% recovery figure for brines of composition similar to that of the KP Lake Resource brine, is possible without redissolution of precrystallised salts.
Now that Reward has confirmed the robustness of the first order SysCAD Flowsheet and Mass Balance Model compiled in the December Quarter 20223, it will undertake an independently verified ESS, currently scheduled for completion by mid-year.
The results from abovementioned laboratory testwork are essential data in the Australian Provisional Patent Application (Application Number – 2022902277) covering the Reward Process. The application was originally submitted on 11 August 2022 with new data to be submitted prior to 11 August 2023 to complete the International application.
Next Steps
Over the next two quarters the company will focus of the following key activities;