Modern Mining June 2019

MINING News

Tiris project delivers first samples of yellowcake

a low capital cost (approximately US$45 million) and rapid project development and construction. The study envisages that Tiris would produce 10,7 Mlb of U 3 O 8 over a 15-year mine life. In the early years of the project, production of 1,0 Mlb/a is anticipated from high-grade areas of the deposit. The process flowsheet adopted for the study begins with wet drum scrub- bing and two stages of wet screening to allow rejection of up to 80 % of the original plant feed as essentially bar- ren waste. The remaining 20 % of fine, enriched pulp will go to standard alka- line leaching followed by ion exchange in a NIMCIX reactor. Uranium will then be stripped from the NIMCIX resin to gener- ate a pregnant solution for precipitation as ammonium diuranate (ADU). After a dewatering step in a centrifuge, the precipitate will be calcined and dried to uranium oxide for packaging and trans- port to customers. 

Sahara Desert has required commitment and stamina from our dedicated techni- cal team. This yellowcake production is a key part of the Tiris DFS and will assist in marketing studies and progression of our financing discussions.” The Tiris project is based on a major greenfields uranium discovery with 49 Mlb U 3 O 8 in current resources from 66 Mt at 334 ppm U 3 O 8 . The project has several natural attributes which result in low capital and operating costs. These include shallow, flat-lying, surface min- eralisation (only 1-5 m deep) within unconsolidated gravels and the fact that the uranium ore can be simply upgraded (wash and screen) by up to 700 % to 2 500 ppm. No grinding is required which makes for major savings. The conceptual 1 Mt/a operation described in the Scoping Study on the project (which was completed in 2014) is designed to take full advantage of these unusual characteristics, whilst providing

Aura Energy, listed on the ASX and AIM, has announced that as part of the Tiris uranium project Definite Feasibility Study (DFS), it has produced its first samples of yellowcake product. Tiris – which Aura is hoping to bring into production next year – is located in Mauritania. Importantly, the yellowcake produced is regarded as ‘saleable’ with impurity lev- els in the product within the acceptable levels relative to the ASTM standards. The UO 4 yellowcake was produced during the Aura test work phase being con- ducted in the Australian Nuclear Science & Technology Organisation (ANSTOMinerals) laboratories. The precipitation test work will continue with further optimisation of the product planned in the next stage of work at ANSTO Minerals. Peter Reeve, Aura Energy’s Executive Chairman, said: “The production of yellow- cake is a true milestone for Aura Energy’s push to achieve producer status. To achieve yellowcake production from our site in the

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