Furthermore, control tests were performed to demonstrate the effect of A. ferrooxidans in uranium bioleaching process and showed that the addition of this . PDF | This review describes the involvement of different microorganisms for the recovery of uranium from the ore. Mainly Acidithiobacillus forrooxidans. initial work on uranium bioleaching in the early s was taken to prevent oxidation rate of iron that may affect uranium’s microbial leaching.
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This is good for the iron exchange system to recover the uranium. For comparison, a single column test is conducted at the same time. The irrigation is powered by a peristaltic pump.
When pH is lower than 1.
A review of the bacterial leaching in the treatment of uranium ores. This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This indicates these ores contain lots of fluoride mineral. However, the peak of 4th column is the highest one and that of the 3rd column is the second.
In the leaching progress, they can be oxidized by ferric iron or O 2 of the solution [ 13 ].
Journal of Nanomaterials
In acidification stage, therefore, the acid concentration should be decreased as well. Sample volumes of liquid were extracted periodically and the pH and redox potential Eh were measured.
Articles from Indian Journal of Microbiology are provided here courtesy of Springer. This system can increase the uranium concentration of PLS. However, the fluoride content 1.
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Thus, the recovery of 4th is greater than that of 3rd column, and that of 3rd is greater than 2nd column and so on. By this technology, the leaching time can be shortened and the recovery of minerals can be improved and the production costs can be reduced.
Uraninite reacts with ferric sulfate to produce soluble uranyl sulfate and ferrous sulfate: Biotechnology As near-surface oxide orebodies are depleted, mines are having to process deeper sulfide ores that are lower in metal grade and metallurgically more complex.
Published online Mar 9. Under these circumstances, the precipitation of both goethite and jarosite-type basic compounds will not occur in the next bioleaching stage and the bacterium will grow in the column as bacteria are adapted to this pH and the culture from the irrigating solution PLS of pH adjustment.
Moreover, the acid consumption of the 1st column and that of the 2nd column are very similar. The uranium recovery is highly leached The ratio of the internal diameter of the column to the height of ore is important for the leaching solution percolates more efficiently.
Continued Multicolumns Bioleaching for Low Grade Uranium Ore at a Certain Uranium Deposit
Because the first column is the initial column in this type of system and the acid amount of PLS from the 1st column is small, the irrigating solution of 2nd column needs to add more acid for pH adjustment using PLS from the 1st column. During bioleaching period, redox potentials increase and uranium concentrations are also increased as shown in Figures 5 and 6. Support Center Support Center.
In China, hard-rock-type uranium such as granite-type deposits are using heap leaching widely in industry. Back-scattered electron image by EPMA before leaching. During this experiment, both redox potentials of irrigating solution and PLS are measured in each day.
As near-surface oxide orebodies are depleted, mines are having to process deeper sulfide ores that are lower in metal grade and metallurgically more complex. These type of precipitations are difficult to be dissolved by strong acid and that will decrease the permeability of the column [ 12 ].
It has been established that this ratio must be greater than 4 and not in excess of 20 in order to avoid any effects of the wall [ 910 ]. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. Afer d of leaching, the last column was unloaded out of this system and a new column was added in. In the acidification period, there occurs a uranium concentration peak.
Figure 6 a shows the uranium concentration of PLS with different column in bioleaching stage.
After days of bioleaching, the uranium recovery was This uranium ore belongs to a low grade type. This work was financially supported by National Plans Grant no.