Peninsula Energy's low-pH in-situ field demonstration yields further improved uranium results

Peninsula Energy Ltd’s (ASX:PEN) (OTCMKTS:PENMF) (FRA:P1M) low-pH in-situ recovery (ISR) field demonstration at the flagship Lance Project in Wyoming, US, has yielded further improved production results.

The pH and free acid concentration of the recovery composite stream has reached target levels and with an Oxygen Reduction Potential (ORP) level consistent at around 400 mv, PEN believes the recovery stream appears to be sufficiently close to the target range of 450 to 600 mv to support higher uranium production grades.

Results meeting targets

Speaking to the update, managing director and CEO Wayne Heili said: “In reviewing the results of the field demonstration over the past few weeks, it is clear that the learnings-based adjustments implemented at Lance were well thought out and appropriate.

“The composite production stream pH and free acid levels are now meeting our control targets and importantly, the uranium solution grade has responded with a strong improvement.

“Information gained during the demonstration operations will be applied to the commercial low-pH approach as the company progresses the Lance Project toward a return to production.”

Increased uranium grade

The recovery composite stream uranium grade has recently increased to approximately 40 ppm and is trending toward continued improvement, compared to the uranium concentration of between 20 and 25 ppm in mid-May.

Achieving and then maintaining the correct operational pH and ORP for the process solutions is critical to successful low-pH ISR uranium operations.

With the pH and free acid target now achieved, the rate of acid addition has been reduced to a rate sufficient to maintain current levels.

As previously reported, a change in the type of oxidant utilized has delivered significant improvement in the injection and recovery stream ORP levels.

Uranium capture – ion exchange

The success of ion exchange (IX) processes is concentration driven and the system technical performance is known to improve with increasing uranium grades.

A pilot-scale IX system has been online since March.

The performance of the IX has improved with the upward trending uranium concentration and it is achieving loading results that are consistent with typical levels for low-pH lixiviant applications.

Peninsula Energy has also continued evaluating several alternative uranium capture/recovery process options which may improve upon standard ion exchange performance.

Evalutations of two proprietary innovative concepts have been advanced with completed desktop evaluations.

A laboratory benchtop assessment of one technology has been planned to be completed in July.

If successful, the testing may be advanced to pilot scale demonstrations that could be run in conjunction with the current field demonstration.

These advanced technologies have the potential to significantly enhance downstream processing performance while reducing operating costs.

Story by ProactiveInvestors