Extraction of uranium in caustic sludge from the production of nuclear fuel components by countercurrent dissolution and acid curing

Journal of Radioanalytical and Nuclear Chemistry - The uraniferous caustic sludge (UCS) produced in the production of uranium fuel components was hardly to leach directly, due to its very low-grade...     

Selective extraction of uranium from uranium–beryllium ore by acid leaching

Journal of Radioanalytical and Nuclear Chemistry - Both uranium and beryllium are very important strategic metals and have been applied to many fields, such as nuclear industries, atomic energy,...     

Removal of high concentrations of NO3− from nuclear industrial wastewater by using a fixed-bed bioreactor

In this work, a down-flow fixed bed anaerobic biofilm reactor filled by biological ceramsites were prepared to remove the high concentration of NO₃^? (>?20 g/L) from nuclear industry wastewaters. The effects of hydraulic retention time, the concentration of NO₃^?, the molar ratio of C/N and temperature on the removal efficiencies of NO₃^? were investigated. The results showed that the removal rate of NO₃^? with the initial concentration of 6 g/L can reach 99% or more by controlling the hydraulic retention time at 0.75 h, the molar ratio of C/N at 1.5 and the temperature over 18 °C. In the process, the NO₂^? was not accumulated, and the autotrophic denitrifying bacteria grow well in anaerobic biofilm reactors, proving a usable method for removing the high concentration NO₃^? from nuclear industrial wastewaters.

     

Mechanism analysis on synergistic leaching of uranium from pyrite oxidized by Acidithiobacillus ferrivorans

Journal of Radioanalytical and Nuclear Chemistry - Low-grade uranium ore, which was challenging to be treated economically by conventional methods, can be treated by uranium leaching by bacteria....     

Characterization and uranium bioleaching performance of mixed iron- and sulfur-oxidizers versus iron-oxidizers

In order to develop and apply mixed iron- and sulfur-oxidizers in uranium bioleaching, the characteristics of a mixed iron- and sulfur-oxidizing consortium (Consortium ISO) were comparatively investigated versus an iron-oxidizing consortium (Consortium IO). The results showed, the Consortium ISO exerted stronger oxidative ability and acid-producing ability than Consortium IO did. The synergy of sulfur-oxidizers and iron-oxidizers could change the structure and properties of the passivation substance, and work positively for eliminating the accumulation of passivation substance. In the bioleaching process, the uranium bioleaching experiments showed the recovery percentage of uranium reached 99.5% with Consortium ISO, 6.3% more than that of Consortium IO.

     

Efficient adsorption of uranium (VI) from aqueous solution by a novel modified steel slag adsorbent

Journal of Radioanalytical and Nuclear Chemistry - Using steel slag as a raw material, a new type of adsorption material has been prepared by acid modification method. The preparation conditions of...