Membrane Study delivers cost savings to Etango
Bannerman Resources Limited this week said that the Etango Membrane Study has been completed successfully, delivering substantial reagent/operating cost reductions along with forecast capital savings, the final quantum of which is to be confirmed in the Etango Definitive Feasibility Study Update (DFS Update).
In an announcement on the SENS platform, Bannerman said the membrane test work undertaken successfully demonstrated the ability of the nano-technology to recover acid for re-use and upgrade the uranium concentration in the solution almost ten-fold.
“The testwork on solution coming from the ion-exchange (IX) circuit demonstrated that a volumetric recovery of 90% was achievable. This further resulted in over 80% of the acid being recovered, along with a corresponding decrease in the volume of neutralisation chemicals required. This confirms that Ion Exchange (IX) with nano-filtration (NF) is favourable to Solvent Extraction (SX) at Etango for both economic and operational reasons. The data obtained through the Membrane Study also provides
valuable input into the DFS Update, which is being progressed through 2018,” the company said in the statement.
According to Bannerman the bulk of the potential savings achieved from using membrane technology are from recovering the majority of the acid for re-use, the consequential reduction in neutralisation chemicals and the reduced equipment size following the membrane plant (given downstream solution volumes are now reduced by
The Membrane Study tested the effectiveness of five different membrane types on two different solution streams, both generated from the Etango Heap Leach Demonstration Plant: Concentrated eluate stream from an ion exchange (IX) process; and Pregnant Liquor Stream coming directly from the heap leach circuit (ie without an IX circuit).
According to the company, the best results were achieved through applying nano-filtration to the concentrated eluate stream, utilising a membrane type that optimally trades-off capital cost of acid-resistance durability in the membranes.
Iron removal was evaluated on the concentrates to remove iron and other entrained species, prior toyellow cake precipitation, confirming the viability of using magnesium oxide (MgO) and/or sodium hydroxide (NaOH) to reduce iron contamination with minimal uranium precipitation.
Subject to confirmatory testwork, it is expected that the precipitated iron can be re-used in the leaching circuit,further reducing operating cost, they added.
Meanwhile, the extent of forecast operating cost reductions and capital savings will be known following definitive engineering associated with the DFS Update, which is now further enhanced by the quality of data produced by the Membrane Study.
Bannerman´s Chief Executive Officer, Mr Brandon Munro, said, “The amenability of the Etango Project to recent advances in established nano-filtration technology is an exciting outcome that further confirms the robust economics and low technical risk of the Etango project. Our technical team undertook the Membrane Study diligently and comprehensively, utilising the unique advantages Bannerman´s Heap Leach Demonstration Plant offers, in particular the access to industrial-scale uranium bearing solution generated from the Etango orebody.”
“I am delighted that this success further enhances Etango, both economically and operationally, as a world-class, highly-advanced and strategically important uranium project,” he concluded.