GoviEx Madaouela
On site at GoviEx's Madaouela project. Feature image courtesy of GoviEx

Dual-listed GoviEx Uranium has revealed that the results of a review study  to identify and assess opportunities to use membrane separation technologies to reduce the capital and operating expenses, at its fully-permitted Madaouela project, have been encouraging.

Niger – The study, performed by Synexus, also looked at increasing efficiency in the recovery of uranium and molybdenum using the membrane separation technologies.

“The potential operating and capital savings highlighted by the review, while preliminary in nature, are very encouraging and support our decision to undertake this assessment. This work underlines GoviEx’s strategy to focus on the optimisation of the Madaouela project,” comments GoviEx CEO Daniel Major.

The review considered five options whereby membrane separation could be potentially utilised in the process plant design as set out in the independent NI 43-101 technical report titled, “The Updated Integrated Development Plan for the Madaouela project, Niger”.

The five options described by the review are as follows:

  • Option 1 – to concentrate uranium and molybdenum, and recover sulfuric acid from the pregnant leach solution.
  • Option 2 – to recover ammonium carbonate, ammonium hydroxide and carry-over molybdenum from the molybdenum solvent extraction circuit strip solution.
  • Option 3 – to recover sulfuric acid and carry-over molybdenum from the molybdenum oxide filter filtrate.
  • Option 4 – to concentrate uranium and recover phosphoric acid from the loaded strip solution.
  • Option 5 – to recover sodium hydroxide and carry-over uranium from the sodium diuranate precipitation filter filtrate (or from the precipitation thickener overflow).

Synexus’ overall approach and methodology for the review was to use the existing process design information as set out in the technical report for the membrane test data simulation models, which were then used to assess membrane performance for each option.

“I am very pleased with the progress our team has made to date in exploring potential mine design and process optimisation opportunities for our Madaouela project. If these efficiencies prove to be fruitful, we will explore the possibility of applying them at our other fully-permitted Mutanga project in Zambia,” notes GoviEx executive chairman Govind Friedland.

Membrane separation could contribute to both capital and operating cost savings because of one or a combination of the following possibilities:

  • Smaller hydraulic capacity of downstream circuit(s) as membrane separation may reduce the volumetric flowrate advancing downstream by between 85% and 90%.
  • More efficient management of solution chemistry may optimise separation of uranium and molybdenum from the acid leach solution and from each other in the membrane concentration step.
  • The required capacity of the sulfuric acid plant may be reduced, directly because of acid recovery and reuse, and indirectly because of the reduction in acid used for pH correction.
  • Reagent consumption may be reduced, in addition to consumption of sulfuric acid, because of recovery and reuse, or because of the reduction in use for pH correction.

The results of the review indicate that the inclusion of membrane separation in the Madaouela project process design, as set out in the technical report, could potentially reduce operating and capital costs and hence improve project economics.

The results are preliminary in nature and require further technical studies; however, these initial results are of a significant enough scale as to support the inclusion of membrane separation in the next-stage feasibility study for the Madaouela project.

The review sets out a series of recommendations, including the following, for GoviEx to consider in determining the possible inclusion of membrane separation in the Madaouela project’s process design:

  • Assess membrane separation in more detail, considering integration and reuse of the membrane recovered solutions as part of the mass balance exercise above.
  • Perform membrane bench-scale tests to confirm recoveries, final concentrations achievable, solutes rejection profile, etc.; to obtain the necessary design information such as flux and operating pressure (specific to membrane selection and solution chemistry); and to update capital and operating cost estimates to feasibility study level.