Acid rock drainage and radiological environmental impacts. A study case of the Uranium mining and milling facilities at Poços de Caldas

Fernandes, Horst Monken; Franklin, Mariza Ramalho; Veiga, Lene H.S.

doi:10.1016/s0956-053x(98)00019-1

Cited by 47 publications

(35 citation statements)

References 9 publications

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“…The earlier work of Beneš and Strejc (1986) showed that for pH lower than 6 the sorption capacity of several minerals drops dramatically to become mostly nil at a pH of around 3. This is a well-known phenomenon in studies of the acid drainage products of uranium mill tailings (e.g., Fernandes et al, 1995Fernandes et al, , 1996Fernandes et al, , 1998Landa, 2003;Abdelouas, 2006). The leaching of uranium mill tailings and associated metal oxides ores by acidic waters at pH from 2 to 5, remobilize large quantities of radionuclides creating an important environmental problem.…”

Section: Depletion Of Radium and Lead Isotopesmentioning

confidence: 98%

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

et al. 2012

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Section: Depletion Of Radium and Lead Isotopesmentioning

confidence: 98%

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

et al. 2012

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“…The process generates a radioactive sludge and presents a high consumption of lime [4,5]. Although chemical treatment can provide effective remediation of AMD and it is relatively simple, it has the drawback of generating a large volume of sludge for disposal in addition to high operating costs.…”

Section: +2mentioning

confidence: 99%

“…Although chemical treatment can provide effective remediation of AMD and it is relatively simple, it has the drawback of generating a large volume of sludge for disposal in addition to high operating costs. According to Fernandes et al [4] in terms of cost versus effectiveness analysis, neutralization process can not be selected as a permanent solution to the problem of Poços de Caldas.…”

Section: +2mentioning

confidence: 99%

Uranium recovery and manganese removal from acid mine drainage

Ladeira

Gonçalves

2008

WIT Transactions on Ecology and the Environment

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This work is aimed at the selection of an appropriate adsorbent for uranium and manganese present in acid mine water drainage. The pH of the acid water is around 2.7, the uranium concentration is in a range of 9-15mg/L, the manganese concentration approximately 170mg/L and the sulphate concentration is near 2000mg/L. The uranium in this solution, where sulphate is present in high levels, is basically in the form of UO 2 (SO 4 ) 3 -4 and the manganese is in the form of Mn +2.The removal of these elements has been studied using activated carbons, gibbsite, zeolite, apatite and biological adsorbent. Among all adsorbents tested, the biological material was the one which presented the best performance taking into account the necessity of removing Mn and U simultaneously. The maximum adsorption capacity varied from 10 to 14 mg U.g -1 and 83 to 123mg Mn.g -1 . The results, obtained by column experiments, showed that the sulphate had a deleterious effect on the uranium recovery by the biological adsorbent. Mn removal was increased with the increase of pH from 2.6 to 7.0. Adsorption of these elements by activated carbons, gibbsite, zeolite and apatite was lower if compared to the biological material.

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“…Chemical treatment can provide reasonable remediation treatment for AMD, however, it has been contested, both technically and economically, due to its high operational and environmental costs incurred from the formation of large amounts of sludge which need to be disposed of [4,5]. In general, the removal of Mn (II) is carried out through the addition of lime, which demands an excessive consumption of reagent as a result of high pH values required for its precipitation [3].…”

Section: Introductionmentioning

confidence: 99%

“…In general, the removal of Mn (II) is carried out through the addition of lime, which demands an excessive consumption of reagent as a result of high pH values required for its precipitation [3]. Even so, after the precipitation, the solution free of manganese cannot be discarded, as it generally has a pH above 10.0 [4]. Another difficulty related to the process of precipitation is the timeconsuming kinetics in the formation of stable precipitates.…”

Section: Introductionmentioning

confidence: 99%

The use of limestone, lime and MnO₂in the removal of soluble manganese from acid mine drainage

Aguiar

Xavier

Ladeira

2010

WIT Transactions on Ecology and the Environment

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Acid mine drainage (AMD) is one of the main environmental issues faced by the mining industry. The acid mine water generally contains metals above the permissible discharging levels. Manganese is particularly present in this effluent and its removal is notoriously difficult due to its high solubility over a wide range of pH. While most of the metals precipitate at a pH below neutrality, the pH necessary for manganese precipitation is very high, above 10. Most systems that effectively remove this element from mine waters use the oxidation of Mn (II) followed by precipitation at an elevated pH. Precipitation consumes a great amount of lime, which implies high operational cost. Besides, the process generates a large amount of sludge containing metals which have to be disposed of. The objective of this study is to optimize the removal of manganese by using a laboratory prepared acid solution and an acid effluent from Poços de Caldas uranium mine (Brazil), in order to achieve the Mn permitted level for discharging (<1mg/L) and to reduce the amount of sludge generated. The precipitation process has been studied using lime, limestone and a nonconventional catalyst/adsorbent (MnO 2 residue). The results obtained showed that both lime and limestone are effective in the removal of Mn in a pH higher than 10. However, there is a slight difference between the two reagents and lime shows a better performance. The volume of precipitate generated by the addition of lime was 50% smaller than that obtained when limestone was used. The use of the non-conventional material made the removal of almost 100% of the Mn possible as the concentration of manganese was reduced from 140mg/L to <1mg/L at a pH near neutrality (6.8 to 7.2). The final effluent complies with the recommended value for manganese discharge.

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Acid rock drainage and radiological environmental impacts. A study case of the Uranium mining and milling facilities at Poços de Caldas

Cited by 47 publications

References 9 publications

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

Uranium recovery and manganese removal from acid mine drainage

The use of limestone, lime and MnO₂in the removal of soluble manganese from acid mine drainage

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Acid rock drainage and radiological environmental impacts. A study case of the Uranium mining and milling facilities at Poços de Caldas

Cited by 47 publications

References 9 publications

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

Radium depletion and 210Pb/226Ra disequilibrium of Mar^|^iacute;taro hydrothermal deposits, Los Azufres geothermal field, Mexico

Uranium recovery and manganese removal from acid mine drainage

The use of limestone, lime and MnO2in the removal of soluble manganese from acid mine drainage

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The use of limestone, lime and MnO₂in the removal of soluble manganese from acid mine drainage