Peninsula Energy Ltd (ASX:PEN) (OTCQB:PENMF) (FRA:P1M) is continuing to collect key data from the MU1A low-pH field demonstration at its flagship, 100%-owned Lance Project in Wyoming, US.
This information will be invaluable as the company progresses the Lance Project toward a return to commercial production.
The primary objective of the present low-pH field demonstration is to operate in an unmined area of the orebody and confirm the optimal operating conditions for Lance, as suggested from laboratory studies completed between 2017 and 2020.
As the scope of the 2019 FLT did not include a full assessment of uranium recovery, the additional field-scale evaluation was planned to provide more complete and definitive data for forecasting, modelling and an eventual return to production.
Once completed, the field demonstration will provide valuable data on the influence of this design criteria, which will in turn inform the design of the optimal commercial-scale production in-situ recovery (ISR) pattern.
Information invaluable
Peninsula managing director and chief executive officer Wayne Heili said “The decision to advance our capabilities and technical understanding of low-pH ISR through the operation of a well-designed field demonstration has been rewarded with the collection of a significant body of data.
“To date, the operations have helped inform us on areas for further focus, including rates of pH adjustment, acid consumption and the need to utilize stronger oxidants.
“This information will be invaluable as the company progresses the Lance Project toward a return to commercial production”.
Maximize uranium solubility
To date, the field demonstration has exhibited a trend toward consuming more acid than was modelled from the laboratory results and subsequently projected in the 2018 feasibility study.
While one of the demonstration patterns has arrived at the target pH of 2.0 S.U., it is taking more time than expected for the other two patterns to reach the recovery pH target.
The two lagging patterns are yielding a recovery pH of about 4.0 S.U. notwithstanding having sustained the objective flow rates and acid concentrations in the injection stream.
PEN will continue to closely monitor the progression of the system pH and will assess opportunities to optimise the process design at the completion of the field demonstration.
A recent series of laboratory tests focused on the importance of achieving and maintaining an adequate oxidation-reduction potential (ORP) to maximise uranium solubility.
Commercially available oxidants can be introduced to achieve ORP targets.
The field demonstration has allowed the company to evaluate the commercial potential of several oxidants.
An additional system for an alternative oxidant, hydrogen peroxide, as used in its laboratory studies, was developed and has recently been successfully commissioned.
Hydrogen peroxide has already proven effective in achieving the target ORP in the field demonstration injection stream and the company is confident that the required chemical conditions for uranium solubility can be established systemwide.
Ion exchange demonstration plant
Uranium solubility and production solution grades are expected to increase as the recovery stream approaches the target pH and oxidation levels.
When this is achieved, the ion exchange demonstration plant will be activated.
Peninsula Energy is also progressing technical evaluations related to the potential for application of membrane separation systems to enhance resin performance, which has the potential to significantly reduce downstream processing and operating costs.
A laboratory-scale test is planned on production solutions from the field demonstration.
A pilot demonstration based on the laboratory test results could be completed in conjunction with the continued operation of the field demonstration.
Next steps
Peninsula will continue to run the field demonstration for the foreseeable future as it generates valuable data related to the specific performance of the low-pH process at Lance.
It is expected that the field demonstration may now run for 18-24 months, an increase of around six months from the operating timeframe originally envisaged.