BIOLEACHING OF URANIUM PDF

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. Thus, during bioleaching, the pH of irrigating solution in the column will be increased. A technology that has not been considered thus far is the tank bioleaching of uranium concentrates. In China, bioleaching has been greatly improved bioleacuing uranium industry.

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This work was financially supported by National Plans Grant no. The cost can be reduced by this technology.

The other reason is that the bacteria can adapt more easily ov the leaching environment which contains high fluorine and other toxic ions after adopting extreme toxic iron environment in former column. The result demonstrates that the highest leaching of base metals is achieved at low pH values under high redox conditions where ferric iron remains in solutions [ 16 ].

After days of bioleaching, the uranium recovery was When the pH value of irrigating solution reaches over 2. For the bacteria culture and the PLS bioleahing irrigation solution changed in turns, the red curves of irrigation solution are more fluctuant than blue curve of PLS. Iron oxidizing bacteria are a good worker who can do this job.

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Continued Multicolumns Bioleaching for Low Grade Uranium Ore at a Certain Uranium Deposit

Bioleaching has lots of advantages compared with traditional heap leaching. In South Africa, uranium was produced as a by-product of gold production in the Witwatersrand Basin, but after the collapse of violeaching uranium market in the s, the uranium plants were mothballed and the uranium was retained in tailings storage facilities.

It improved the iron exchange system to recover uranium. Biopeaching bioleaching period, redox potentials increase and uranium concentrations are also increased as shown in Figures 5 and 6. In this paper, one of the biggest granite uranium deposits located in south China with high fluoride mineral is selected for study.

The company who owns this deposit needs a new technology to solve this problem. However, the peak of 4th column is the highest one and that biolexching the 3rd column is the second. In this type of system, one purpose is the increasing redox potentials of this system; the other purpose is that the iron oxidizing bacteria can grow in the column.

Before irrigation of the former column, the pH of PLS should be adjusted to 1. In recent years, there has been an upsurge in uranium exploration across the globe, driven by a renewed interest in nuclear energy and higher uranium prices.

Materials and Methods 2. In many cases, bioleaching is the most suitable process. World J Mic Biotech. Most of sixth valence uranium minerals are leaching because they can dissolve in acid normally. Author information Article notes Copyright and License information Disclaimer.

This indicates that once pyrite is leached; the surface area of those uraninite and coffinite minerals will be greatly increased.

However, some consumptive acid minerals in small fractures will be reacted more slowly. And then in the next bioleaching stage, acid consumption still increase slowly because some acid needs to be added in the bacteria domestication pond for pH adjustment and there are still some consumptive acid minerals in tiny fracture which are not reacted by acid in the former stage. Please review our privacy policy. For introduction of bacterial leaching process at uranium leaching can enhance the kinetics of leaching and strengthen its process, bioleaching has been paid great attention in uranium industry in recent years.

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After bioleaching period, redox potentials of PLS are significantly higher than the correspondence leaching solutions. In the s, Mintek undertook extensive research into the bioleaching of typical Witwatersrand uranium- and gold-bearing ores and concentrates.

When pH is lower than 1. Chemical and mineralogical composition of the ore sample used in column bioleaching.

Bioleaching of low-grade uranium ore using Acidithiobacillus ferrooxidans

This technology has been used in the production [ 23 ] or is still in the laboratory research stage [ 4 ]. The uranium recovery is highly leached A study of the bioleaching of a Spanish uranium ore. All of these characteristics were observed during the isolation of the strain used. 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.

Redox potentials of from 1st column to 4th column are presented in Figures 5 a5 b5 cand 5 d.