Uranium operations look to improve performance

Peninsula Energy Limited has formally submitted a request to the Wyoming Department of Environmental Quality (WDEQ) to amend its existing permit to allow the use of a low-pH recovery solution at the Lance uranium project in Wyoming, USA. This is expected to increase recovery rates and improve the cost profile of the project. Meanwhile, a study has highlighted the potential of membrane separation to improve economics at GoviEx Uranium's Madouela project in Niger.

The WDEQ Permit to Mine for the Lance project currently authorises the use of alkaline and oxidant solutions, generated by mixing native groundwater with carbon dioxide and/or sodium bicarbonate and gaseous oxygen, at the in-situ leach (ISL) project. However, the deposit has proved to be only moderately amenable to these alkaline solutions since uranium recovery began at the Ross Permit Area in December 2015, and recovery rates remain below targeted levels.

Madouela economics

The use of membrane separation technologies could potentially lead to savings in both operational and capital costs at the Madouela uranium project in Niger, a study commissioned by Vancouver-based GoviEx Uranium has found.

The review of five options where membrane separation could potentially be used at the fully permitted uranium and molybdenum project was carried out by Synexus Pty Ltd. Although the initial results are preliminary in nature and require further technical studies, GoviEx said the initial findings were "of a significant enough scale as to support the inclusion of membrane separation in the next-stage feasibility study" for the project.

"If these efficiencies prove to be fruitful at the Madaouela Project, we will explore the possibility of applying them at our other fully-permitted project: the Mutanga Project in Zambia," GoviEx Exeuctive Chairman Govind Friedland said.

During the first quarter of 2018, the Lance project produced 43,638 pounds U3O8 (19.8 tU), Subiaco, Western Australia-based Peninsula announced on 6 April. This was an increase of about 12% on the previous quarter. Tests using mildly acidic solutions have previously shown greatly increased recovery, with solution grades over 10 times higher than the 22 mg per litre achieved in actual alkaline operations.

Peninsula started the process to amend the licence and permits for the in-situ leach (ISL) project last year, after laboratory tests showed greatly increased recovery using a mildly acidic rather than the alkaline mining solution. The company in November 2017 issued for public review a White Paper which summarised the results of the tests, which used sulphuric acid at low concentrations of 1.5% or less.

A successful transition to low pH operations could align the operating performance and cost profile of the Lance project with current industry-leading global uranium production projects, Peninsula said, adding that 96% of the 77 million pounds of uranium produced worldwide by ISL methods in 2015 came from facilities using low pH lixiviants.

The proposed change to low pH operations at Lance would require no oxidant and improve ground water restoration, the company said, with laboratory tests and modelling indicating that groundwater can be fully restored to the currently approved values after using low-pH solutions.

Peninsula CEO, Wayne Heili, said the submission of the amendment request by Peninsula's wholly owned subsidiary, Strata Energy Inc. was the culmination of many months of research, extensive test work and analysis aimed at "greatly enhancing" the uranium recovery process at Lance.

The WDEQ will now carry out a comprehensive review of the amendment request, including analysing the test results and inviting public comments.

Researched and written
by World Nuclear News