Análise de múltiplas variáveis no fechamento de mina: estudo de caso da pilha de estéril BF-4, Mina Osamu Utsumi, INB Caldas, Minas Gerais

Nóbrega, Flávia Andrade; Lima, Hernani Mota de; Leite, Adilson do Lago

doi:10.1590/s0370-44672008000200014

Cited by 18 publications

(12 citation statements)

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“…Moreover, ecologic characterization of microorganisms involved in oxidative dissolution of metallic sulfides is also extremely important for understanding the perturbations in natural environments resulting from acid mine drainage (Kock and Schippers 2008;Yang et al 2008;Rowe et al 2007). Acid mine drainage in a uranium mine is relevant because of its environmental impact and neutralization cost (Nóbrega et al 2008).…”

Section: Introductionmentioning

confidence: 99%

“…This mine was commercially explored by the Ore Treatment Unit (UTM) of Brazilian Nuclear Industries S/A INB (Garcia 1989) from 1982 to 1995, after which the operations were suspended, leaving INB responsible for remediation of the area. Legal procedures for remediation of the area and facility decommissioning are under way (Nóbrega 2007). The main environmental problems in UTM uranium mine include acid drainage (1,414,851 m 3 year -1 ) from the pit mine, waste rock (89,120,000 t) and tailing dam (Cipriani 2002;Benedetto et al 2005).…”

Section: Introductionmentioning

confidence: 99%

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Environmental assessment of water from a uranium mine (Caldas, Minas Gerais State, Brazil) in a decommissioning operation

et al. 2010

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The present study was carried out in a uranium ore mining area located in Caldas, in the southern region of the state of Minas Gerais, Brazil. The present study was undertaken to evaluate the ecologies of populations of the bioleaching microorganisms (Acidithiobacillus ferrooxidans and A. thiooxidans) in effluents from mining companies containing sulfides and associated radionuclides, and to assess the physico-chemical and radiological uranium mining impact on surface water quality. Water samples collected from eight points were analyzed chemically and microbiologically. In water samples from points in the region called the pit mine-waste rock piles, high average oxide-reduction potential value (429-525 mV), high ferrous ion concentration (0.72-12.56 mg L -1 ), low average pH value (3.37-3.47) and highest average population densities of A. ferrooxidans (59-2,551 MPN mL -1 ) and A. thiooxidans (833-6,359 MPN mL -1 ) were detected. These findings indicate that these points are the main places of acid mine drainage and biolixiviation action in the Ore Treatment Unit (UTM). The study reported here also found that water quality in the point considered a link between the UTM and the environment was degraded. These points should be considered as critical sites in the event of a decommissioning act. The average concentration values of fluorite (10.60 mg L -1 ) and manganese (10.49 mg L -1 ) in the water samples of treated effluents are above the limits permitted by law. Long-term utilization of these waters is considered to be unhealthy for the local environment and humans.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Environmental assessment of water from a uranium mine (Caldas, Minas Gerais State, Brazil) in a decommissioning operation

et al. 2010

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“…More recently, numerical models for simulating water flow and relevant geochemical processes in the site (Franklin, 2007) and alternatives to mitigate the impacts caused by the WPR4 (Nóbrega, 2007) were investigated in the area. Also, previous studies made a hydrogeochemical investigation of the Antas River, in order to verify the contamination in water courses downstream the mine, and the natural attenuation was considered responsible for mitigate the contamination from effluent releases in the area (Lamego et al, 2009).…”

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confidence: 99%

Radiometric Evaluation in a Uranium Mine under a Decommisioning Processs

Ferreira¹,

Filho²,

Rodrigues³

et al. 2012

EER

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Mining activities generate several impacts. Besides the environmental damages, the exploration of radioactive minerals, such as uranium and thorium, is responsible for another kind of problems and concerns. Radioactive materials can remain dangerous for long time periods, what requires radioprotection measures in order to protect the health of the workers and the public in general. This work shows the results of a radiometric survey done in a uranium mine that is under a decommissioning process, in the southeast region of Brazil. The results show that there is potassium and radium in almost the whole region called Waste Rock Pile number 4, where tons of wastes are deposited. However, the radiation values are under the permissible limits for workers, although the place can not be considered as a free area, according to the Brazilian rules.

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“…Uranium was discovered in the area in 1948, geological research commenced in 1964 and mining in 1982. This mine then became the first to produce yellow cake (concentrated of uranium) in Brazil (Nóbrega et al 2008). The deposit is hosted in Mezozoic alkaline volcanic, subvolcanic and plutonic rocks, usually containing uranium, thorium and rare earth elements (Ulbrich 1984).…”

Section: Introductionmentioning

confidence: 99%

“…The deposit is hosted in Mezozoic alkaline volcanic, subvolcanic and plutonic rocks, usually containing uranium, thorium and rare earth elements (Ulbrich 1984). The mine was closed in 1995, but the demand for acid mine drainage (AMD) treatment is still around 300 m 3 /h (Nóbrega et al 2008), so it requires on-going efforts and investment. For this reason, this mine is a good case-study for investigation of rare earth elements (REE) in mining effluents.…”

Section: Introductionmentioning

confidence: 99%

Removal of lanthanum, cerium, europium and holmium from water by co-precipitation with iron and aluminium (hydr)oxides

Barcelos¹

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Effluents from mining activities may have high concentrations of trace elements such as arsenic, rare earth elements (REE) and actinides, mainly in areas where acid mine drainage (AMD) occurs. Use of lime to neutralise AMD also promote co-precipitation of iron (Fe) and aluminium (Al) (hydr)oxides, increasing the removal of trace elements from water. This study aimed to evaluate the efficiency of Fe/Al (hydr)oxides co-precipitation to remove lanthanum (La), cerium (Ce), europium (Eu) and holmium (Ho) from water under laboratory conditions. Two sets of experiments were performed with individual REE solutions containing Eu and Ho. In these cases, Fe(II) and Al sulphates were used at different Fe:Al:REE molar ratios. Two other sets of experiments with Fe(II) and Fe(III) sulphates were performed in a mixed REE solution containing La, Ce, Eu and Ho. To coprecipitate Fe/Al (hydr)oxides, pH's were raised to 9.0 and 6.0 with 5 mol L-1 KOH solution. Soluble contents of Fe, Al and REE were periodically measured in supernatants aliquots. Precipitates were collected at the end of the 60-day incubation period and, then, oven-dried, sieved and characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The stability of REE in precipitates was also assessed by BCR sequential extractions. All treatments presented high REE removal efficiency from water at pH 9.0, but significantly lower at pH 6.0 for Fe(II) treatments. Magnetite precipitation was favoured by lower contents of REE and Al, whereas goethite and lepidocrocite were favoured at higher contents. Segregated phases were not detected for Eu and Ho, but lanthanite and cerianite precipitated at high amounts of La and Ce, respectively. For mixed REE treatments, the mineralogical phases precipitated were mostly poorly crystallised. The presence of magnetite was associated to higher REE stabilities, whereas lepidocrocite decreased the stability as measured by BCR extractions. The presence of segregated phases as cerianite resulted in increased Ce stability, but presence of lanthanite decreased La stability in precipitates.

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Análise de múltiplas variáveis no fechamento de mina: estudo de caso da pilha de estéril BF-4, Mina Osamu Utsumi, INB Caldas, Minas Gerais

Abstract: The Osamu Utsumi Mine of the Indústrias Nucleares do Brasil (INB), located in Caldas/MG, extracted and processed uranium from 1982 to 1995, after which, operations

Cited by 18 publications

References 1 publication

Environmental assessment of water from a uranium mine (Caldas, Minas Gerais State, Brazil) in a decommissioning operation

Environmental assessment of water from a uranium mine (Caldas, Minas Gerais State, Brazil) in a decommissioning operation

Radiometric Evaluation in a Uranium Mine under a Decommisioning Processs

Removal of lanthanum, cerium, europium and holmium from water by co-precipitation with iron and aluminium (hydr)oxides

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