ORCID Profile
0000-0001-6755-2115
Current Organisation
Flinders University
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Publisher: Springer Science and Business Media LLC
Date: 26-02-2019
Publisher: American Chemical Society (ACS)
Date: 13-09-2017
Abstract: Acid and metalliferous release occurring when sulfide (principally pyrite)-containing rock from mining activities and from natural environments is exposed to the elements is acknowledged as a major environmental problem. Acid rock drainage (ARD) management is both challenging and costly for operating and legacy mine sites. Current technological solutions are expensive and focused on treating ARD on release rather than preventing it at source. We describe here a viable, practical mechanism for reduced ARD through the formation of silicate-stabilized iron oxyhydroxide surface layers. Without silicate, oxidized pyrite particles form an overlayer of crystalline goethite or lepidocrocite with porous structure. With silicate addition, a smooth, continuous, coherent and apparently amorphous iron oxyhydroxide surface layer is observed, with consequent pyrite dissolution rates reduced by more than 90% at neutral pH. Silicate is structurally incorporated within this layer and inhibits the phase transformation from amorphous iron (oxy)hydroxide to goethite, resulting in pyrite surface passivation. This is confirmed by computational simulation, suggesting that silicate-doping of a pseudoamorphous iron oxyhydroxide (ferrihydrite structure) is thermodynamically more stable than the equivalent undoped structure. This mechanism and its controlling factors are described. As a consequence of the greatly reduced acid generation rate, neutralization from on-site available reactive silicate minerals may be used to maintain neutral pH, after initial limestone addition to achieve neutral pH, thus maintaining the integrity of these layers for effective ARD management.
Publisher: AIP Publishing
Date: 10-2010
DOI: 10.1063/1.3484281
Abstract: A hydrothermal cell with 320 ml internal volume has been designed and constructed for in situ neutron diffraction studies of hydrothermal crystallizations. The cell design adopts a dumbbell configuration assembled with standard commercial stainless steel components and a zero-scattering Ti–Zr alloy s le compartment. The fluid movement and heat transfer are simply driven by natural convection due to the natural temperature gradient along the fluid path, so that the temperature at the s le compartment can be stably sustained by heating the fluid in the bottom fluid reservoir. The cell can operate at temperatures up to 300 °C and pressures up to 90 bars and is suitable for studying reactions requiring a large volume of hydrothermal fluid to d out the negative effect from the change of fluid composition during the course of the reactions. The capability of the cell was demonstrated by a hydrothermal phase transformation investigation from leucite (KAlSi2O6) to analcime (NaAlSi2O6⋅H2O) at 210 °C on the high intensity powder diffractometer Wombat in ANSTO. The kinetics of the transformation has been resolved by collecting diffraction patterns every 10 min followed by Rietveld quantitative phase analysis. The classical Avrami/Arrhenius analysis gives an activation energy of 82.3±1.1 kJ mol−1. Estimations of the reaction rate under natural environments by extrapolations agree well with petrological observations.
Publisher: Elsevier BV
Date: 2013
Publisher: Mineralogical Society of America
Date: 11-2011
DOI: 10.2138/AM.2011.3691
Publisher: Wiley
Date: 30-03-2007
Publisher: MDPI AG
Date: 26-05-2020
DOI: 10.3390/MIN10060485
Abstract: The aim of this study was to determine the reactivity of the chalcopyrite (112) surface under industrially relevant leaching conditions. Leaching of the chalcopyrite (112) surface was carried out at approximately pH 1 and in the presence of 0.01 M ferric or ferrous. The atomic force microscopy (AFM) and Raman microspectroscopy analyses suggested that the chalcopyrite (112) surface was relatively inert, with no formation of elemental sulfur observed over 42 days of leaching. In addition, it was found that the distribution of Fe-S and Cu-S bonds was always negatively correlated, as revealed by Raman analysis. This suggested that the breakage of the Fe-S and Cu-S bonds did not occur concurrently at a specific reaction site. The rate of variation of surface roughness, as reflected by AFM data, also suggested that leaching of the chalcopyrite (112) surface in the ferric or ferrous solution medium likely occurred more rapidly in the initial stage (fewer than seven days) than in the later stage (after seven days).
Publisher: Elsevier BV
Date: 02-2017
Publisher: Elsevier BV
Date: 10-2008
Publisher: MDPI AG
Date: 28-08-2015
DOI: 10.3390/MET5031566
Publisher: Elsevier BV
Date: 2019
Publisher: International Union of Crystallography (IUCr)
Date: 26-03-2010
DOI: 10.1107/S0021889810006990
Abstract: A flow-through cell for hydrothermal phase transformation studies by in situ and time-resolved neutron diffraction has been designed and constructed. The cell has a large internal volume of 320 ml and can operate at temperatures up to 573 K under autogenous vapor pressures ( ca 8.5 × 10 6 Pa). The fluid flow is driven by a thermosyphon, which is achieved by the proper design of temperature difference around the closed loop. The main body of the cell is made of stainless steel (316 type), but the s le compartment is constructed from non-scattering Ti–Zr alloy. The cell has been successfully commissioned on Australia's new high-intensity powder diffractometer WOMBAT at the Australian Nuclear Science and Technology Organization, using two simple phase transformation reactions from KAlSi 2 O 6 (leucite) to NaAlSi 2 O 6 ·H 2 O (analcime) and then back from NaAlSi 2 O 6 ·H 2 O to KAlSi 2 O 6 as ex les. The demonstration proved that the cell is an excellent tool for probing hydrothermal crystallization. By collecting diffraction data every 5 min, it was clearly seen that KAlSi 2 O 6 was progressively transformed to NaAlSi 2 O 6 ·H 2 O in a sodium chloride solution, and the produced NaAlSi 2 O 6 ·H 2 O was progressively transformed back to KAlSi 2 O 6 in a potassium carbonate solution.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.NUT.2017.10.017
Abstract: To determine dietary patterns (DPs) and explain the highest variance of vitamin B A total of 2173 adolescents who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for the vitamin B intake analysis (46% boys) and 586 adolescents for the biomarkers analysis (47% boys). Two non-consecutive, 24-h, dietary recalls were used to assess the mean intakes. Concentrations were measured by chromatography and immunoassay testing. A reduced rank regression was applied to elucidate the combined effect of food intake of vitamin B and related concentrations. The identified DPs (one per vitamin B intake and biomarker and by sex) explained a variability between 34.2% and 23.7% of the vitamin B intake and between 17.2% and 7% of the biomarkers. In the reduced rank regression models, fish, eggs, cheese, whole milk and buttermilk intakes were loaded positively for vitamin B intake in both sexes however, soft drinks and chocolate were loaded negatively. For the biomarkers, a higher variability was observed in the patterns in terms of food loads such as alcoholic drinks, sugars, and soft drinks. Some food items were loaded differently between intakes and biomarkers such as fish products, which was loaded positively for intakes but negatively for plasma folate in girls. The identified DPs explained up to 34.2% and 17.2% of the variability of the vitamin B intake and plasma concentrations, respectively, in European adolescents. Further studies are needed to elucidate the factors that determine such patterns.
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 10-2013
Publisher: MDPI AG
Date: 17-03-2017
DOI: 10.3390/MIN7030042
Publisher: Elsevier BV
Date: 07-2015
Publisher: MDPI AG
Date: 19-06-2017
DOI: 10.3390/MIN7060105
Publisher: MDPI AG
Date: 10-08-2016
DOI: 10.3390/MIN6030083
Publisher: American Chemical Society (ACS)
Date: 03-10-2018
Abstract: The aim of this study was to test the performance of a novel method for acid rock drainage (ARD) control through the formation of Al(OH)
Publisher: Optica Publishing Group
Date: 22-05-2014
DOI: 10.1364/OME.4.001213
Publisher: Elsevier BV
Date: 09-2017
Publisher: International Union of Crystallography (IUCr)
Date: 15-03-2012
DOI: 10.1107/S0021889812002300
Abstract: A large-volume single-pass flow-through cell for in situ neutron diffraction investigation of hydrothermal crystallization processes is reported. The cell is much more versatile than previous designs owing to the ability to control independently and precisely temperature (up to 673 K), pressure (up to 46 MPa), flow rate (0.01–10 ml min −1 ) and reaction-fluid volume (≥65 ml). Such versatility is realized by an innovative design consisting of a room-temperature and ambient-pressure external fluid supply module, a high-pressure reaction module which includes a high-temperature s le compartment enclosed in a vacuum furnace, and a room-temperature and high-pressure backpressure regulation module for pressure control. The cell provides a new avenue for studying various parameters of hydrothermal crystallizations independently, in situ and in real time at extreme hydrothermal conditions ( e.g. supercritical). The cell was successfully commissioned on the high-intensity powder diffractometer beamline, Wombat, at the Australian Nuclear Science and Technology Organisation by investigating the effect of pressure on the hydrothermal pseudomorphic conversion from SrSO 4 (celestine) to SrCO 3 (strontianite) at a constant temperature of 473 K and flow rate of 5 ml min −1 . The results show that the increase of pressure exerts a nonlinear effect on the conversion rate, which first increases with increasing pressure from 14 to 20 MPa, and then decreases when pressure further increases to 24 MPa.
Publisher: MDPI AG
Date: 30-05-2017
DOI: 10.3390/MIN7060089
Publisher: American Chemical Society (ACS)
Date: 16-09-2019
Abstract: The aim of this study was to determine the combined effect of galvanic interaction and silicate addition on the dissolution of pyrite, the major contributor to acid and metalliferous drainage (AMD). Single (pyrite, sphalerite, and galena)- and bi-sulfide (pyrite-sphalerite and pyrite-galena) batch dissolution experiments were carried out with addition of 0.8 mM dissolved silicate for comparison to previously published data. The pyrite dissolution rate was reduced by 98% upon silicate addition at pH 7.4 with little effect at pH 3.0 and 5.0. The effect of galvanic interaction on reducing pyrite dissolution decreased with increasing pH and was greater in the presence of sphalerite than galena. In contrast, the effect of silicate addition increased with increasing pH and was greater in the presence of galena than sphalerite. The greatest combined effect was at pH 7.4, with <0.1% of pyrite leached in both bi-sulfide systems. Silicate addition also significantly reduced the dissolution of sphalerite or galena (by 10-44%, except at pH 3 for the pyrite-sphalerite system). These results suggest that silicate addition, for reducing both pyrite dissolution and metalliferous drainage, may be applicable at a broad pH in mixed sulfide systems.
Publisher: Elsevier BV
Date: 04-2009
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 03-2015
Publisher: Mineralogical Society
Date: 04-2011
DOI: 10.1180/MINMAG.2011.075.2.279
Abstract: The accurate measurement of trace element concentrations in natural sulphides by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been limited by the lack of matrix-matched calibration standards. The synthesis of a standard, IMER-1, by incorporating four minor and 34 trace elements into a chalcogenide glass matrix Ge 28 Sb 12 S 60 is reported here. Chemical analysis by electron probe microanalysis (EPMA), LA-ICP-MS, solution ICP-MS, and inductively coupled plasma-optical emission spectroscopy (ICP-OES) confirmed the excellent homogeneity of major elements (1-σ relative standard deviation (RSD) % for S, Sb and Ge) and acceptable homogeneity of most trace elements (1-σ RSD %). The standard was validated by analysing trace-elements concentrations in three geological pyrite specimens using IMER-1 as the calibration standard and comparing the results to previously reported values also determined by LA-ICP-MS but using a different calibration standard. STDGL2b-2. The results suggest that IMER-1 may be an appropriate calibration standard for LA-ICP-MS analysis of trace elements in natural sulphides.
Publisher: Elsevier BV
Date: 09-2007
Publisher: Elsevier BV
Date: 09-2007
Publisher: Elsevier BV
Date: 06-2016
Publisher: MDPI AG
Date: 28-02-2022
DOI: 10.3390/NANO12050810
Abstract: The recyclable utilization of waste biomass is increasingly important for the development of a sustainable society. Here, the sawdust-derived activated carbon (SD-AC) has been prepared via a convenient H3PO4-based activation method and further trialed as an electrode for use as a high-performance symmetric supercapacitor. The as-prepared SD-AC possesses a hierarchically porous structure with micropores (0.55 nm) and mesopores (2.58 nm), accounting for its high specific surface area of 621 m2 g−1, with a pore volume of 0.35 cm3 g−1. Such a hierarchically porous structure can offer a favorable pathway for fast ion penetration and transportation, enhancing its electrochemical performance. As a result, the SD-AC electrode exhibits a maximum specific capacitance of up to 244.1 F g−1 at 1.0 A g−1, a high rate capability (129.06 F g−1 at 20 A g−1), and an excellent cycling performance, with 87% retention over 10,000 cycles at 10 A g−1. Of particular note is that the SD-AC-based symmetric supercapacitor achieves a maximum energy density of 19.9 Wh kg−1 at the power density of 650 W kg−1, with a long-term cycle lifespan. This work showcases the recyclable utilization of waste biomass for the preparation of high-value activated carbon for efficient energy storage.
Publisher: Elsevier BV
Date: 10-2010
Publisher: American Chemical Society (ACS)
Date: 28-01-2021
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 10-2019
Publisher: American Chemical Society (ACS)
Date: 02-04-2018
Abstract: Although the acid generating properties of pyrite (FeS
Start Date: 2012
End Date: 2012
Funder: Australian Synchrotron
View Funded ActivityStart Date: 2014
End Date: 2014
Funder: Australian Synchrotron
View Funded ActivityStart Date: 2017
End Date: 2019
Funder: National Natural Science Foundation of China
View Funded ActivityStart Date: 2014
End Date: 2017
Funder: Australian Research Council
View Funded Activity