Browsing by Author "Babij, T"

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    Microbial ecology of Rum Jungle III : leaching behaviour of sulphidic waste material under controlled conditions
    (Australian Atomic Energy Commission, 1981-12) Babij, T; Goodman, AE; Khalid, AM; Ralph, BJ
    The discharge into river systems of acid and heavy metals generated by leaching of sulphidic waste materials at the abandoned opencut uranium mine at Rum Jungle Northern Territory is causing continuing pollution of the surrounding environment. The maximum effects of acid and microorganisms on samples from the overburden dump material under defined and controlled environmental conditions were assessed using reactor systems. These samples came from the overburden dump resulting from the mining of White's orebody. Similarly the stability of tailings material under conditions of flooding and increasing acidity was determined. At ph 2.5 metals in White's dump material were solubilised by acid attack only whereas at pH 3.5 bacterial activity (principally that of Thiobacillus ferrooxidans) generated acidity and contributed significantly to metal release. Under microaerophilic conditions Thiobacillus ferrooxidans continued to effect metal release from the ore but did not produce further acidity. If White's overburden is returned to the acidic flooded opencuts complete solubilisation of the material will occur. The exclusion of oxygen from the dump will not necessarily stop bacterially catalysed leaching processes. Under highly aerated and agitated flooded conditions the tailings material was not active except for copper release of about 2 g kg -1 ore at pH 4.0. The only deleterious element released by increasing acidity was copper which was 100 per cent solubilised at pH 2.5. Uranium was always lss than 3 mu g kg -1 ore and lead was detected only at pH 2.5. Indigenous leaching bacteria did not develop.