Salt Lake Potash Ltd’s (ASX:SO4) (LON:SO4) pumping of initial brine extraction drilled into the paleochannel at Lake Way SOP Project in Western Australia has delivered flow rates of 18 litres per second with a consistent potassium grade of 7,100mg per litre.
The results, which were sustained over a 17-day delivery, are above the average flow rates used in the company’s bankable feasibility study (BFS) which demonstrated 8 litres per second and average brine grades of 6,100mg per litre.
Investors have responded positively with ASX shares up as much as 10% to A$0.50 intra-day and have risen from 30 cents at close on March 19.
Highlights value of paleochannel resource
Chief executive officer Tony Swiericzuk said: “Strong results from pumping our first brine abstraction bore validates work undertaken as part of the BFS and highlights the value of the paleochannel resource, which will be a significant contributor of brine supply to our ponds over the life of the project.”
The response to pumping observed in a monitoring bore 1.6 kilometres away indicates continuity of the aquifer, whilst brine samples also indicate a consistent grade within this zone of the paleochannel.
Two additional brine extraction bores have been completed along the paleochannel with pumping expected to commence in the near term.
In each case, the primary basal sand aquifer was encountered in line with the company's geological model prediction.
Paleo channel drilling
In April Salt Lake started drilling its first brine extraction bore into the paleochannel basal sands at Lake Way.
This bore was located at Pad 17 with two monitoring bores also drilled adjacent.
During the test pumping brine samples were taken every 24 hours.
Potassium and sulphate grades were consistent throughout, averaging 7,100mg per litre and 29,700mg per litre, respectively.
The 17-day duration of the test and constant pumping rate of 18 litres per second was sufficient to stress the aquifer and to model the long-term aquifer response to pumping.
In the months ahead SO4 will drill and test pump further brine extraction bores along the eastern side of Lake Way.
During May bores have been completed at Pads 8 and 21, with test pumping expected to be completed in the near term.