Institute for Mineral and Energy Resources publications

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Now showing 1 - 20 of 42

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A duality of timescales: short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave-Albany-Fraser Orogen
(Elsevier, 2015) Tucker, N.; Hand, M.; Kelsey, D.; Dutch, R.
Abstract not available
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A model study of copper rougher recovery optimisation at PT Freeport Indonesia
(Australasian Institute of Mining and Metallurgy, 2007) Grano, S.; Akroyd, T.; Mular, M.; Nelson, M.; Mill Operators' Conference (9th : 2007 : Fremantle, Western Australia); Institute for Mineral and Energy Resources
A fundamental model, which considers the subprocesses of particle collection by bubbles in flotation, is applied to two comprehensive flotation surveys in the rougher stages of C3 concentrator, PT Freeport Indonesia. The flotation surveys focused on the collection of: • cell-by-cell and size-by-size metallurgical, • cell hydrodynamic, and • pulp and surface chemistry information. The two surveys were conducted at significantly different feed tonnages, giving rise to significantly different feed particle size distributions, pulp densities and mean pulp residence times. A series of model simulations are performed with the aim of quantifying changes in copper recovery, on both a size-by-size and unsized basis, with changes in values of the hydrodynamic parameters and hydrophobicity of the copper sulfide mineral. This was carried out in an effort to identify the most promising route to increase overall copper recovery in roughing. It was found that by increasing the hydrophobicity of the copper sulfide mineral surfaces it became possible to optimise cell hydrodynamics, which targeted increased fine (-12 μm) copper sulfide mineral recovery but without adversely affecting coarse (+150 μm) copper sulfide mineral recovery.
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A Study of Detachment of Model Coarse Particles from Bubbles Using a Novel Electro-Acoustic Technique
(Engineers Australia, 2009) Xu, D.; Ametov, I.; Grano, S.; CHEMECA (37th : 2009 : Perth, Australia); Institute for Mineral and Energy Resources
In this paper, a detachment of particles from bubbles was investigated using a novel electro-acoustic technique. The experimental setup consisted of a loudspeaker connected to a computer through an amplifier. A teflon capillary tube was attached to the membrane of a loudspeaker. A bubble-particle aggregate on the other end of the capillary tube was subjected to vibration when the sinusoidal signal of fixed frequency and amplitude generated by the computer was transmitted to the loudspeaker. The critical amplitude of particle detachment was determined at a fixed frequency (50 Hz). The detachment experiments were conducted using model quartz particles of various size and hydrophobicity. Results showed that particles (600-850 m) with high contact angle (90 degree) required high amplitudes for detachment from bubbles. In contrast, quartz particles with low contact angle (49 degree) exhibited the considerably lower critical detachment amplitude. The critical detachment amplitude was related to the stability of bubble-particle aggregates. The results of electro-acoustic experiments correlated well with the outcomes of corresponding bench flotation tests.
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An assessment of activated carbon cloth microporosity change due to chemical activation
(Pergamon-Elsevier Science Ltd, 2010) Badalyan, A.; Bromball, R.; Pendleton, P.; Skinner, W.; Institute for Mineral and Energy Resources
Controlled modification of micropore volumes of samples from the FM1-series of activated carbon cloth can be achieved via selective oxidation: strong caustic treatment leads to an increase in volume, while peroxydisulfate treatment leads to a decrease in volume. Pore volume increases are determined to be due to inorganic content leaching, determined via XPS analyses, developing small primary micropores for the least activated carbon cloth (FM1/250) and a widening of the pore width for the most activated carbon cloth (FM1/700). All cloths exhibited Type I nitrogen adsorption isotherms both prior to and post oxidative treatment. © 2009 Elsevier Ltd. All rights reserved.
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Analysis of uncertainties in manometric gas-adsorption measurements II: Uncertainty in alpha S-analyses and pore volumes
(Academic Press Inc Elsevier Science, 2008) Badalyan, A.; Pendleton, P.; Institute for Mineral and Energy Resources
We describe procedures to propagate the uncertainty in adsorption data and alpha(S)-values to generate uncertainty in apparent primary, secondary, and total micropore volumes for porous activated carbons exhibiting Type I and IV character. The alpha(S)-data are interpolated from selected non-porous reference material (NPRM) adsorption isotherm data with some adsorbents exhibiting surface chemistry quite different from and some similar to that of the porous adsorbents (PA). We show that a statistically constant apparent total micropore volume can be determined independent of the NPRM surface chemistry. In contrast, NPRM surface chemistry appears to influence our ability to identify unequivocally the filling and condensation ranges of micropore filling, leading to statistically different apparent primary and secondary micropore volumes.
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Assessment of chloramination control strategy based on free-ammonia concentration
(IWA Publishing, 2009) Motzko, S.; Fabris, R.; Badalyan, A.; Henderson, R.; Chow, C.; Vitanage, D.; Institute for Mineral and Energy Resources
A new approach of using free-ammonia measurements as the basis of a control strategy to optimise a chloraminated water distribution system was tested in a laboratory evaluation. A test rig with a newly developed low level on-line free-ammonia analyser was constructed to investigate two different control configurations, the currently used feedback and the proposed feedforward. The results of this trial showed that only using the free-ammonia analyser for feedback control is not ideal due to its inability to detect chlorine overdosing situations. Better results regarding the maximum yield of disinfectant residuals when using the feedforward configuration were observed, and free-ammonia concentrations below 0.065 mg/L were consistently achieved.
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Benchmarking the flotation performance of ores
(Pergamon-Elsevier Science Ltd, 2012) Muganda, S.; Zanin, M.; Grano, S.; Institute for Mineral and Energy Resources
A porphyry copper ore containing chalcopyrite as the principal copper bearing mineral, and pyrite as the only other sulphide mineral, was treated in batch flotation tests under well defined physical conditions. The size-by-size flotation response was benchmarked against established calibration curves to infer an operational contact angle of the sulphide minerals as a function of particle size. The inferred operational contact angle values of the sulphide minerals were validated by independent measurements of contact angle on the concentrates and, in the case of chalcopyrite, by an indirect approach using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). Recovery, flotation rate, and inferred operational contact angle increased with collector addition across all size fractions, with the intermediate and coarse size fractions benefitting the most from increased collector addition. The directly measured and inferred operational contact angles were in reasonable agreement, with an R ² value of 0.7 across all size fractions. There was good agreement between the advancing contact angle values determined using ToF-SIMS and those calculated from direct contact angle measurement on the 53-75 μm size fraction for the case of chalcopyrite. A method for benchmarking flotation response has been developed, which may lead to better flotation process diagnostics and modelling. © 2011 Elsevier Ltd. All rights reserved.
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Characterization of the Khamaseen (spring) dust in Jordan
(Pergamon-Elsevier Science Ltd, 2009) Abed, A.; Al Kuisi, M.; Abul Khair, H.
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Compressional intracontinental orogens: ancient and modern perspectives
(Elsevier B.V., 2014) Raimondo, T.; Hand, M.; Collins, W.
Abstract not available
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Copper and molybdenite recovery in plant and batch laboratory cells in porphyry copper rougher flotation
(Science Press, 2008) Ametov, I.; Grano, S.; Zanin, M.; Gredelj, S.; Magnuson, R.; Bolles, T.; Triffett, B.; International Mineral Processing Congress (IMPC) (24th : 2008 : Beijing, China)
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Dependence of MILD combustion on fuel-air injection pattern within a recuperative furnace
(University of Queensland, 2009) Craig, R.; Dally, B.; Mi, J.; Australian Combustion Symposium (2009 : Brisbane, Qld.); Institute for Mineral and Energy Resources
A MILD combustion furnace was used to examine the feasibility of both counterflow and co-flow firing of reactants: natural gas (91.4% CH4) and air. It was found that the stability of MILD combustion under the counterflow conditions is highly sensitive to the momentum ratio of fuel to air ejecting into the furnace and that the present furnace geometry does not lend itself to this flow configuration. For most of the counterflow conditions studied, the exhaust gasses contained unburned hydrocarbons as well as high levels of CO and H2, implying that fuel short circuiting was occurring inside the furnace. In contrast, the co-flow firing configurations, especially with premixing of the reactants, have proven to work extremely well. Very low emissions of CO, H2 and NOx were recorded for a variety of equivalence ratios and firing rates.
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Diagenetic and epigenetic alteration of Cretaceous to Paleogene organic rich sedimentary successions in northwestern Jordan, typical of the western margin of the Arabian Plate
(Gulf Petrolink, 2009) Dill, H.; Kus, J.; Abed, A.; Sachsenhofer, R.; Abul Khair, H.; Institute for Mineral and Energy Resources
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Effect of grinding media on the activation of pyrite flotation
(Pergamon-Elsevier Science Ltd, 2010) Peng, Y.; Grano, S.; Institute for Mineral and Energy Resources
In previous study, it has been found that the grinding conditions have a great effect on the flotation of chalcopyrite and galena as well as their separation from pyrite (Peng et al., 2003a,b). In this study, the effect of the grinding conditions on the activation of pyrite by Cu²⁺ and Pb²⁺ were investigated. Based on flotation behaviour, EDTA (ethylene diamine-tetra acid) extraction, pulp potential measurement and electrokinetic study, it is found that the activation of pyrite flotation by Cu²⁺ and Pb²⁺ involves different mechanisms. Reduction of copper(II) to copper(I) and the formation of new copper sulphide phases are responsible for the activation of pyrite flotation by Cu²⁺. This is an electrochemical process. However, adsorption of lead hydroxide on pyrite surface is principally responsible for the activation of pyrite flotation by Pb²⁺. The effect of grinding media on the flotation of pyrite activated by Cu²⁺ or Pb²⁺ is through the change of pulp potential and iron oxidation species emanating from the media. The iron oxidation species from grinding media is electrostatically repulsive with respect to copper-activated pyrite and therefore, reducing conditions produced by mild steel medium promotes pyrite flotation in the presence of Cu²⁺. However, iron oxidation species from grinding media is electrostatically attractive with respect to lead-activated pyrite and therefore inert grinding medium favours pyrite flotation in the presence of Pb²⁺. This study provides a clear picture of how to increase or decrease pyrite flotation through a smart selection of grinding media. © 2010 Elsevier Ltd. All rights reserved.
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Effect of iron contamination from grinding media on the flotation of sulphide minerals of different particle size
(Elsevier Science BV, 2010) Peng, Y.; Grano, S.; Institute for Mineral and Energy Resources
In a previous study, it was found that iron contamination from grinding media played a dominant role in depressing galena and chalcopyrite flotation (Y. Peng, S. Grano, D. Fornasiero, J. Ralston, Control of grinding conditions in the flotation of chalcopyrite and its separation from pyrite, Int. J. Miner. Process. 69 (2003) 87-100; Y. Peng, S. Grano, D. Fornasiero, J. Ralston, Control of grinding conditions in the flotation of galena and its separation from pyrite, Int. J. Miner. Process. 70 (2003) 67-82). In the current study, the effect of iron contamination on the flotation of galena and chalcopyrite on a particle size basis was investigated. It was observed that fine galena and chalcopyrite (- 10 μm) were affected by iron oxidation species emanating from grinding media to a much greater extent than intermediate size fractions (+ 10-53 μm), and that grinding conditions had a more pronounced effect on fine galena flotation than fine chalcopyrite flotation. Mechanisms were investigated by rest potential measurement, ToF-SIMS analysis, mineral dissolution study and zeta potential measurement. It appears that fine particles (- 10 μm) are more easily oxidised than intermediate particles resulting in a higher concentration of metal oxidation species. Oxidation of galena and chalcopyrite enhances adsorption of iron oxidation species at pH 9 by electrostatic interaction. Fine oxidised galena has a stronger affinity for iron oxidation species than fine oxidised chalcopyrite. © 2010 Elsevier B.V. All rights reserved.
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Effects of surface functional groups of activated carbon on adsorption of triclosan from aqueous solution
(Inderscience Publishers, 2009) Fang, S.; Pendleton, P.; Badalyan, A.; Environmental Research Event (ERE) (10 Dec 2006 : Sydney)
We report adsorption of triclosan by using activated carbons as a potential method to improve the discharge water purification process. Commercially available activated carbons, P1300, Picazine HP and Hydrodarco C, display different levels of affinity for triclosan from aqueous solution. Surface chemistry of these adsorbents were modified via reduction, oxidation and nitridation, to improve and better understand the adsorption process. The adsorption capacity was greatly influenced by surface group changes, with a decrease in relative affinity on oxidation. Nitridation enhanced the amounts adsorbed over the thermally reduced samples. Surface analysis via X-ray Photoelectron Spectroscopy (XPS) helped us identify the introduced surface functional group changes. Overall, nitridation resulted in an increased basic character of the surface exploiting the Lewis acidic nature of triclosan when it is dissolved in solution. The surface chemistry modified adsorbents suggest that adsorption from solution is a viable methodology for triclosan control during wastewater treatment.
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Factors affecting froth stability in mineral flotation and implications on minerals recovery: A case of study
(GECAMIN Ltd, 2008) Zanin, M.; Gredelj, S.; Grano, S.; International Mineral Processing Seminar (5th : 2008 : Santiago, Chile); Casali, A.; Gomez, C.; Kuyvenhoven, R.; Institute for Mineral and Energy Resources
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Flotation behaviour of fine particles with respect to contact angle
(Inst Chemical Engineers, 2012) Chipfunhu, D.; Zanin, M.; Grano, S.; Institute for Mineral and Energy Resources
The flotation behaviour of methylated quartz particles of different size, but within the size range from 0.2 to 50μm, and varying contact angle, was probed in a mechanical flotation cell. Results suggest that particles of a given size need to possess a minimum critical contact angle (θ crit) for flotation to occur. This behaviour is shown not to be solely dependent on fine particles having lower collision efficiency with bubbles, but rather due to a combination of low collision efficiency and particles not having enough kinetic energy at collision with bubbles to form the three phase line of contact and initiate the attachment process. In the particle size range investigated, the critical contact angle increases with a decrease in particle size. © 2011 The Institution of Chemical Engineers.
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Flotation behaviour of sulphide mineral size fractions with controlled contact angle
(Engineers Australia, 2008) Muganda, S.; Zanin, M.; Grano, S.; CHEMECA (36th : 2008 : Newcastle, Australia); Institute for Minerals and Energy Resources (IMER)
The flotation response of chalcopyrite has been characterized as a function of particle size and advancing contact angle. The advancing contact angle of individual size fractions was manipulated to different values, measured using the Washburn technique. A flotation feed sample was constituted from the individual size fractions. Parameters such as frother concentration, impeller rotational speed, and superficial gas velocity were the same in each flotation test. The chalcopyrite sample, in the absence of any steps to intentionally manipulate the contact angle, displayed advancing contact angles which varied with particle size fraction. In the presence of a standard thiol collector, the advancing contact angle was also particle size dependent, with the -20 micron fraction displaying the lowest contact angle. Flotation tests showed that the chalcopyrite size fractions above 20 microns floated independently of each other, and that the flotation response was the same for the same particle contact angle and size fraction across different flotation tests. The flotation response was characterized by the maximum recovery at infinite flotation time and the distributed rate constant, assuming a single floatable fraction existed within each size fraction. When the distributed and undistributed rate constants were compared, the latter gave a greater dependency on contact angle as it took into account the non-floating fraction. The two rate constants converged at high advancing contact angles as the non-floating fraction approached zero. Further work on mineral floatability characterization will lead to the development of calibration curves of rate constant against particle size and contact angle, a tool that could be used to benchmark flotation response.
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Flotation Rate Constant Prediction for Metal Sulfide Particles
(AusIMM, 2005) Ralston, J.; Fornasiero, D.; Grano, S.; Duan, F.; Akroyd, T.; Centenary of Flotation Symposium (2005 : Brisbane, Queensland); Johnson, G.; Institute for Mineral and Energy Resources
We have determined the experimental rate constants for chalcopyrite particles floated from a complex sulfide ore and compared them with those calculated using a recently developed flotation model. The model incorporates contributions from the efficiencies of collision, attachment and stability between particles and bubbles, as well as their frequency of collision. For these calculations, the contact angle of the chalcopyrite particles in the ore was obtained independently using a surface spectroscopic approach. The calculated flotation rate constants were in good agreement with the experimental data and able to reproduce the characteristic maximum in flotation rate constant for particles of intermediate size. The values of bubble velocity and turbulent dissipation energy derived from these calculations are relatively low and may well correspond to mean values of these parameters inside the flotation cell. We have extended this approach through the application of a property based model to an operating plant, with a satisfactory outcome.
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Free chlorine analysers: a user's selection guide
(Australian Water Association Inc, 2009) Badalyan, A.; Holmes, M.; Chow, C.; Vitanage, D.
Selecting new instrumentation for integration into water quality monitoring programs is fraught with uncertainties and potential pitfalls. An evaluation methodology for assisting water managers and operators to make the correct choice of an online free chlorine (FC) analyser based on key performance parameters is presented. Eight amperometric and one colorimetric online FC monitors were evaluated against 15 metrological parameters (response, delay, rise and fall times, linearity, limit of quantification, day-to-day repeatability, the effect of interferences, etc.) according to the procedure outlined in the two standards: ISO Standards 8466-1 (1990) and 15839 (2003). The test results were compared with the analysers' technical characteristics supplied by their manufacturers. In general, colorimetric systems performed better than amperometric systems, with the latter experiencing significant interference from the pH of water which was not adjusted during tests. All analysers performed within manufacturers' claimed limits for some metrological parameters, whereas for other parameters their performance was not adequate. It is strongly encouraged to perform evaluation tests under conditions similar to those in the field before purchasing a monitor.

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