Akademik Veri Yönetim Sistemi
International Symposium on Advanced Engineering Technologies (ISADET), Kahramanmaraş, Türkiye, 16 - 18 Haziran 2022, ss.18
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).