Biotecnology For in-Situ Recovery of Uranium


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Turysbekova G., Altynbek A., Bektay Y., Mukanov E., Kalmukambetov A., Yalçın M. G., ...More

International Symposium on Advanced Engineering Technologies (ISADET), Kahramanmaraş, Turkey, 16 - 18 June 2022, pp.18

  • Publication Type: Conference Paper / Summary Text
  • City: Kahramanmaraş
  • Country: Turkey
  • Page Numbers: pp.18
  • Akdeniz University Affiliated: Yes

Abstract

Technology  of in-situ recovery (ISR) of uranium give opportunity for Kazakhstan to increase production 15 times from 800 ton in 1998 till  22 000 ton in 2013. This process is example of zero wastes technology.  Uranium in the ore body is usually presented as hexavalent (soluble) and tetravalent uranium (slightly soluble). To convert uranium into a soluble form, it is necessary to oxidize tetravalent uranium. Oxidation of tetravalent uranium was obtained by the formation of ferric iron at the expense of iron-oxidizing bacteria A.Ferrooxidans. Investigations showed the results of pilot tests at a uranium mine to oxidize ferrous iron oxidation  and to increase the redox  in  two  20 m3 a flow bioreactor bioreactors of new construction.  The redox of the leaching solution rose from 360 mV to 430-450 mV in bioreactors. The content of ferric iron increased from  0.1 g/l to 1.5 g/l and higher. Temperature of leaching solution was 10-140C in order to decrease cost for heating.  Concentration of uranium in the productive solution increased by 10-20 % without adding additional sulfuric acid. Test with additional sulfuric acid  give 40 % increasing of uranium in production solution. The costs of using the technology are 6-8 times lower in comparison with using chemical oxidizers (hydrogen peroxide).