Browsing by Subject "Froth flotation"

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    Mitigating acid rock drainage risks while recovering low-sulfur coal from ultrafine colliery wastes using froth flotation
    (Elsevier, 2012) Mbamba, C Kazadi; Harrison, S T L; Franzidis, J-P; Broadhurst J L
    Ultrafine coal wastes contain sulfide minerals, particularly pyrite, which oxidize and give rise to acid rock drainage (ARD) resulting in extensive and prolonged contamination of local ground and surface waters. Currently, mining operations emphasise an end-of-pipe approach to ARD management using costly chemical or biological treatment techniques, which do not address the long term problem of achieving sustainable closure solutions within the resource lifetime. Eliminating ARD potential before waste disposal would have a major beneficial impact on water quality and facilitate long term closure solutions. Recovering a saleable coal product would be an added economic incentive. This paper presents the results of an investigation to establish the feasibility of a two-stage flotation process to produce: (i) a low-volume sulfide-rich concentrate, (ii) a high-volume benign (low sulfur) tailings, and (iii) a coal concentrate. Laboratory-scale batch flotation experiments were carried out using an oily collector to float coal from samples of coal ultrafines and a xanthate collector to recover acid-generating sulfides. The results of acid generating potential tests (both static and biokinetic) indicate that a low-sulfur tailings with low ARD potential may be produced, together with a coal ultrafine concentrate stream with a low ash content.
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    Mitigating the generation of acid mine drainage from copper sulphide tailings impoundments in perpetuity: A case study for an integrated management strategy
    (Elsevier, 2010) Hesketh, A H; Broadhurst, J L; Harrison, S T L
    Acid mine drainage (AMD) is one of the most serious and pervasive challenges facing the minerals industry. Current philosophy in sulfide tailings management takes an end-of-pipe approach which is yet to be shown to be sufficient to prevent post-closure impacts from AMD and guarantee “walk-away” status. An improved, integrated approach to tailings management and AMD mitigation is proposed, whereby conventional tailings are separated with the use of flotation into a largely benign tailings stream and a sulfide-rich product. The key features of this conceptual approach are outlined and partly demonstrated for the case of porphyry-type copper sulfide tailings. The significance of this approach is that it provides a basis for the identification of opportunities for the development of new process designs incorporating waste management systems for mitigating AMD in a manner consistent with the principles of cleaner production and sustainable development.