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A parametric study of a longwall district climatic prediction and planning model

- Lowndes, I. S., Yang, Z. Y., Kingman, S. W., Silvester, S. A., Tuck, Michael

  • Authors: Lowndes, I. S. , Yang, Z. Y. , Kingman, S. W. , Silvester, S. A. , Tuck, Michael
  • Date: 2006
  • Type: Text , Journal article
  • Relation: Transactions of the Institutions of Mining and Metallurgy, Section A: Mining Technology Vol. 115, no. 3 (2006), p. 99-111
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  • Description: The present paper reports the results of a series of parametric and correlation studies that have been conducted on a longwall coal district climatic prediction planning model developed at the University of Nottingham. The results of these simulation exercises have been correlated against continuously recorded climatic survey data collected from longwall coal districts at two representative deep UK coal mines. The survey data used was continuously measured to record the climate across the longwall districts during both weekday production periods and weekend non-production periods. An analysis of the measured data was able to establish average dry and wet bulb temperatures, which characterised the climate within the workings during weekday production and weekend non-production periods. To determine the major contribution that the geothermal properties of the surrounding rock mass have on the heat transfer to the ventilating air stream, a series of climatic simulation and correlation exercises were conducted to establish a base line data set for these parameters during non-production periods. A second series of parametric and correlation exercises were conducted on the longwall climatic simulation model to identify the range of values to be taken by the parameters governing the contribution of heat transfer from the installed electrical machinery and cut mineral during the weekday production periods. It is concluded that these exercises were able to identify a base set of values for the model input parameters that enabled the longwall climatic models to satisfactorily replicate the climatic conditions experienced across two representative UK deep mine longwall districts during production and non-production periods. © 2006 Institute of Materials, Minerals and Mining.
  • Description: C1
  • Description: 2003001640

Comparison of fuel economies of high efficiency diesel and hydrogen engines powering a compact car with a flywheel based kinetic energy recovery systems

- Boretti, Alberto

  • Authors: Boretti, Alberto
  • Date: 2010
  • Type: Text , Journal article
  • Relation: International Journal of Hydrogen Energy Vol. 35, no. 16 (2010), p. 8417-8424
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  • Description: Coupling of small turbocharged high efficiency diesel engines with flywheel based kinetic energy recovery systems is the best option now available to reduce fuel energy usage and reduce green house gas (GHG) emissions. The paper describes engine and vehicle models to generate engine brake specific fuel consumption maps and compute vehicle fuel economies over driving cycles, and applies these models to evaluate the benefits of a H2ICEs developed with the direct injection jet ignition engine concept to further reduce the fuel energy usage of a compact car equipped with a with a flywheel based kinetic energy recovery systems. The car equipped with a 1.2 L TDI Diesel engine and KERS consumes 25 g/km of fuel producing 79.2 g/km of CO2 using 1.09 MJ/km of fuel energy. These CO2 and fuel energy values are more than 10% better than those of today's best hybrid electric vehicle. The car equipped with a 1.6 L DI-JI H2ICE engine consumes 8.3 g/km of fuel, corresponding to only 0.99 MJ/km of fuel energy. © 2010

A phi-model solution for the inverse position problem of calibrated robots using virtual elementary motions

- Sultan, Ibrahim, Wager, John

  • Authors: Sultan, Ibrahim , Wager, John
  • Date: 2001
  • Type: Text , Journal article
  • Relation: Inverse Problems in Engineering Vol. 9, no. 3 (2001), p. 261-285
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  • Description: It is central to the control of manipulators to calculate the set/sets of joint-displacements which correspond to a given spatial pose (position and orientation) of the end-effector. This problem, which is referred to as the inverse position problem, represents one of the most difficult mathematical challenges in the field of robotics, particularly when performed for calibrated robots (or robots with general structures). In such cases, closed form solutions are too impractical to implement and iterative solutions suffer from numerical singularities. In the present work a procedure is introduced to obtain multiple inverse position solutions for serial robotic structures. For calibrated robots, the procedure involves a simple iterative technique designed to ensure fast convergence and eliminate the occurrence of singularity. However, inverse position solutions for spherical-wrist manipulators will be obtained in a straight-forward non-iterative fashion. A published kinematic notation, referred to as the phi -model, was used to develop the system equations.

Fuel cycle CO2-e targets of renewable hydrogen as a realistic transportation fuel in Australia

- Boretti, Alberto

  • Authors: Boretti, Alberto
  • Date: 2011
  • Type: Text , Journal article
  • Relation: International Journal of Hydrogen Energy Vol. 35, no. 5 (2011), p. 3290-3301
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  • Description: The claim of catastrophic man made climate change or global warming through anthropogenic CO2 has presently focused the interest on the tailpipe emissions of CO2 per km, with recent legislations obsessively targeting these emissions of CO2 with defectively implemented procedures. With a variety of different propulsion solutions (electric, hybrid electric, hybrid mechanic, conventional) and different fuels (Diesel, Petrol, alternative fossil, alternative renewable) available in the near future, a more comprehensive approach based on the full fuel cycle, and eventually also the full life cycle of the vehicle appear to be necessary. The paper is a contribution to trigger further improvement to currently implemented procedures. The paper discusses the CO2 emission data in the present form, some simple but effective measures to improve the accuracy of the data collection procedure, and propose results of fuel cycle CO2-e analysis of vehicles with electric and thermal engines having different fuels. Vehicles with advanced internal combustion engines and power trains fuelled with Diesel may reach CO2-e values of 100 g/km in Australia. Use of bio-ethanol in these vehicles may deliver in Australia a significant reduction of CO2-e emissions to values below 36 g/km. Emission factors for Victoria are presently 1.23 kg CO2-e/kWh for the purchased electricity and vehicles powered by electric motors will need a significant reduction of this indirect CO2-e emission to become competitive. Values below 0.5 kg CO2-e/kWh are needed to make electric cars competitive with Diesel cars while values below 0.1 kg CO2-e/kWh are needed to make electric cars competitive with bio-ethanol cars. Compared with all these alternatives, renewable hydrogen may possibly compete with Diesel when produced with renewable energy sources and made available at the pump for less than 0.1 kg CO2-e/MJ of fuel energy, and with bio-ethanol if produced and distributed at a cost below 0.02 kg CO2-e/MJ of fuel energy.

Fine coal recovery utilizing landfill-derived liquids

- Hall, Stephen

  • Authors: Hall, Stephen
  • Date: 2002
  • Type: Text , Journal article
  • Relation: International Journal of Surface Mining, Reclamation and Environment Vol. 16, no. 1 (2002), p. 40-47
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  • Description: Liquid effluents that arise in the landfilling of municipal solid wastes, both leachate and gas condensates, can replace some or all of the conventional coal flotation reagents. The waste management industry currently must treat these effluents, to destroy contained organics, prior to their discharge to the environment and hence they are available at no cost, or even with "dollars attached". These landfill-derived liquids contain valuable short-chain fatty acids (e.g. valeric and caproic acids) that act as both frother and collector in flotation processes. They can be further concentrated by membrane filtration to reduce the transport costs of such liquids and the ease of their use in coal recovery systems. This paper will discuss how these liquids are formed in landfills, their typical compositions and how they can be employed to recover fine coal. Data from both conventional flotation feeds (-0.5 mm) and column flotation feeds (-0.1 mm) is presented.
  • Description: 2003000130

Stoichiometric H2ICEs with water injection

- Boretti, Alberto

  • Authors: Boretti, Alberto
  • Date: 2011
  • Type: Text , Journal article
  • Relation: International Journal of Hydrogen Energy Vol. 36, no. 7 (2011), p. 4469-4473
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  • Description: For the most part, gasoline engines operate close to stoichiometry because of the high power density and the easy after treatment through the very well established three-way catalytic converter technology. The lean burn gasoline engine suffers major disadvantages for the after treatment still requiring aggressive research and development to meet future emission standards more than for the lower power density compensated by the better fuel conversion efficiency running lean. Hydrogen engines are usually run ultra-lean to avoid abnormal combustion phenomena and possibly to avoid the emission of nitrogen oxides without the difficult non-stoichiometric after treatment. While the ultra-lean combustion of hydrogen may reduce the formation of NOx within the cylinder but makes the power density very low, the only lean combustion of hydrogen requires after treatment for NOx reduction. The suppression of abnormal combustion in hydrogen engines has been a challenge for the three regimes of abnormal combustion, knock (auto ignition of the end gas region), pre-ignition (uncontrolled ignition induced by a hot spot prior of the spark ignition) and backfire (premature ignition during the intake stroke, which could be seen as an early form of pre-ignition). Direct injection and jet ignition coupled to port water injection are used here to avoid the occurrence of all these abnormal combustion phenomena as well as to control the temperature of gases to turbine in a turbocharged stoichiometric hydrogen engine. © 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Bicentennial gold 88 endowment: The university of Ballarat international geological excursion to New Zealand, 2006

- Carey, Stephen

  • Authors: Carey, Stephen
  • Date: 2007
  • Type: Text , Journal article
  • Relation: AusIMM Bulletin Vol. , no. 6 (2007), p. 81-82
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  • Description: The University of Ballarat organizes international excursion for its undergraduate geology students to provide them an opportunity to learn and gain international experiences of geology. The university previously organized an excursion of New Zealand in November-December 2006 to provide students knowledge about plate boundary and gold mineralization. The excursion was sponsored by Oxiana Limited, the Bicentennial Gold 88 Endowment, Newmont Australia Limited, and Castlemaine Goldfields Ltd. The excursion was planned for 17 days and visit to the Taupo Volcanic Zone, Kaikoura, The Waipara, Mt Cook and the Tasman Glacier, Macraes gold mine, Otago's silcretes, Queenstowm, and Milford Sound. More information about 2006-excursion can be found on the website at http://www.ausimm.com.au/main/education/award-bice-gold-php.

Inverse geometric design for a class of rotary positive displacement machines

- Sultan, Ibrahim

  • Authors: Sultan, Ibrahim
  • Date: 2008
  • Type: Text , Journal article
  • Relation: Inverse Problems in Science and Engineering Vol. 16, no. 2 (2008), p. 127-139
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  • Description: Inverse design techniques in the area of fluid mechanics are normally conducted for continuous flow turbomachines rather than positive displacement devices. However, the work in this article is concerned with a class of rotary positive displacement device referred to as the limaçon-to-limaçon machine. The rotors and housings of these machines are manufactured of limaçon profiles, and are likely to suffer from interference if the rotors are not carefully profiled. Published literature indicates that solutions proposed to tackle the interference problem in these machines will adversely affect their efficiency figures. This notion motivated the work presented in this article, which first introduces the relevant mathematical models of the limaçon-to-limaçon machine and then uses these models to construct an inverse geometric design problem formulation. The proposed model has been coded in a computer program that utilises a Marquardt-Levenberg technique to converge to the required geometric parameters. Case studies are presented at the end of the article to verify the validity of the proposed inverse design model.
  • Description: C1

Vehicle driving cycle performance of the spark-less di-ji hydrogen engine

- Boretti, Alberto

  • Authors: Boretti, Alberto
  • Date: 2010
  • Type: Text , Journal article
  • Relation: International Journal of Hydrogen Energy Vol. 35, no. 10 (2010), p. 4702-4714
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  • Description: The paper describes coupled CFD combustion simulations and CAE engine performance computations to describe the operation over the full range of load and speed of an always lean burn, Direct Injection Jet Ignition (DI-JI) hydrogen engine. Jet ignition pre-chambers and direct injection are enablers of high efficiencies and load control by quantity of fuel injected. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the spark-less pre-chamber of the DI-JI engine, where it mixes with the air entering from the main chamber and auto-ignites because of the high temperature of the hot glow plug. Then, jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. Engine maps of brake specific fuel consumption vs. speed and brake mean effective pressure are computed first. CAE vehicle simulations are finally performed evaluating the fuel consumption over emission cycles of a vehicle equipped with this engine. © 2010 Professor T. Nejat Veziroglu.
  • Description: The paper describes coupled CFD combustion simulations and CAE engine performance computations to describe the operation over the full range of load and speed of an always lean burn, Direct Injection Jet Ignition (DI-JI) hydrogen engine. Jet ignition pre-chambers and direct injection are enablers of high efficiencies and load control by quantity of fuel injected. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the spark-less pre-chamber of the DI-JI engine, where it mixes with the air entering from the main chamber and auto-ignites because of the high temperature of the hot glow plug. Then, jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. Engine maps of brake specific fuel consumption vs. speed and brake mean effective pressure are computed first. CAE vehicle simulations are finally performed evaluating the fuel consumption over emission cycles of a vehicle equipped with this engine. © 2010 Professor T. Nejat Veziroglu.

Coastal rock fall hazard identification, Barwon Heads, Victoria

- Dahlhaus, Peter, Muller, B., Miner, Anthony

Slope stability analysis using deterministic and probabilistic approaches for poorly defined stratigraphies

- Ghadrdan, Moshen, Dyson, Ashley, Shaghaghi, Tahereh, Tolooiyan, Ali

  • Authors: Ghadrdan, Moshen , Dyson, Ashley , Shaghaghi, Tahereh , Tolooiyan, Ali
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 7, no. 1 (2021), p.
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  • Description: The stability of slopes directly affects human lives, the environment, and the economy. Inaccurate geological profiles within numerical slope stability models can lead to potentially catastrophic consequences when model conditions do not appropriately reflect real-life stratigraphy. In cases where localised deposits are prevalent, probabilistic methods are often necessary to accommodate for unknown or poorly defined stratigraphies. Currently, there are no commercial geotechnical software packages that simulate probabilistic constitutive behaviour of materials within finite element methods for large-scale stratigraphic analysis. Instead, commercially available probabilistic methods such as the random limit equilibrium method are incapable of incorporating non-linear constitutive soil behaviour. For this reason, advanced constitutive models are seldom coupled with probabilistically varying soil layers or spatially variable soil parameters. The objective of this research is the implementation of a simplified method for probabilistic stratigraphic analysis within a commercially available FE environment, providing a technique to assess the effects of stratigraphic uncertainty on slope stability. The proposed method is presented, highlighting the impact of localised thin layers of soft material as well as their frequency and location on the slope of an operational open-pit mine. The significance of these stratigraphic effects is presented through a case study of Australia’s second-largest open-pit mine, at which the stability of a collapsed coal slope is analysed. To improve the reliability of the finite element method for slope stability assessment, the Monte Carlo approach has been incorporated to consider varying shear strength distributions for models incorporating advanced constitutive behaviour. Thicker probabilistically generated deposits of silty material resulted in increased slope Factors of Safety. Similarly, greater proportions of silty deposits within a predominantly clayey interseam produced larger safety factors than slopes without localised thin silty layers. Stratigraphic analysis indicated that the Factor of Safety was most sensitive to localised silt layers at depths greater than 83 m below ground level. © 2020, Springer Nature Switzerland AG.

Modelling auto ignition of hydrogen in a jet ignition pre-chamber

- Boretti, Alberto

  • Authors: Boretti, Alberto
  • Date: 2010
  • Type: Text , Journal article
  • Relation: International Journal of Hydrogen Energy Vol. 35, no. 8 (2010), p. 3881-3890
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  • Description: Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. © 2010 Professor T. Nejat Veziroglu.

Properties of aged mixed nickel-cobalt hydroxide intermediates produced from acid leach solutions and subsequent metal recovery

- Jones, Andrew, Welham, Nicholas

  • Authors: Jones, Andrew , Welham, Nicholas
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Hydrometallurgy Vol. 103, no. 1-4 (2010), p. 173-179
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  • Description: Synthetic mixed nickel-cobalt hydroxide precipitates (MHP) were produced containing varying levels of Ni, Co, Mn, Mg, Al, Fe, Cr, Cu, Zn and Si to understand and characterize the ageing processes and subsequent nickel and cobalt leach recovery. Precipitates were monitored over a 12 week period using X-ray diffraction (XRD), scanning electron microscopy (SEM) and leach tests in ammonia-ammonium carbonate solution. Manganese and cobalt incorporation into MHP was beneficial for subsequent nickel recovery; most likely preventing or slowing nickel-magnesium hydroxide formation. High magnesium MHP generally lowered subsequent nickel recovery due to its stability and slow leaching kinetics. Between 94-100% Ni and 84-100% Co were leached from nearly all high magnesium MHP precipitates after soaking in the leach solution for 72 h, except for the precipitate containing about 5% Al which only recovered 87% Ni and 61% Co. An XRD of this precipitate showed that it was much more amorphous than any other MHP whilst the XRD of the leach residues revealed a magnesium-aluminium hydrotalcite structure. Both nickel-magnesium hydroxide and hydrotalcite-like structures appear to inhibit nickel and cobalt recovery because of their slow leaching characteristics. © 2010 Elsevier B.V.
  • Description: 2003008226

Electro-osmotic and hydraulic flow rates through kaolinite and bentonite clays

- Jayasekera, Samudra

  • Authors: Jayasekera, Samudra
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Australian Geomechanics Vol. 39, no. 2 (2004), p. 79-86
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  • Description: The objective of this paper is to discuss the effects of electrokinetics on the rate of flow of water through some low penneable clay soils. Experiments were carried out on test specimens prepared by compacting commerciully available kaolinite and sodium bentonite clays. Using falling head penneability tests, hydraulic conductivity values of these clay soils were determined. Subsequently, the experiments were repeated under different electric gradients to assess the effects of electrokinetics on the rate of flow. The flow characteristics were evaluated using the rate of electrooslllotic flow of water Q, (em'/s), coefficient of electroosmotic penneability k, (cm'lY/s), coetlicient of water transport etliciency k; (cm'/Amp/s). The test results suggest that the rate of flow of water through low penneable clay soils is significantly increased by some orders of magnitude due to the application of a direct current. This flow increase appears to be more pronounced for clays that have lower hydraulic conductivity values. It is noticed that electroosl1lotic penneability is independent ofclay type while the voltage gradienl has minimal effect on electroosmotic rate of flow for the tested clay soils.
  • Description: C1
  • Description: 2003000716

100th volume editorial

- Muir, David, Welham, Nicholas, Osseo-Asare, K.

Effects of electrokinetic treatments on the properties of a salt affected soil

- Jayasekera, Samudra, Mewett, John, Hall, Stephen

  • Authors: Jayasekera, Samudra , Mewett, John , Hall, Stephen
  • Date: 2004
  • Type: Text , Journal article
  • Relation: Australian Geomechanics Vol. 39, no. 4 (2004), p. 33-46
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  • Description: This paper presents experimental results of a study undertaken to investigate the effects of electrokinetic treatments on selected chemical and physical properties of a salt contaminated (saline) soil. The study was conducted as a laboratory scale pilot project using locally available saline soil samples. The soil was subjected to an electric gradient by passing a direct current between inserted electrodes. After certain electrokinetic treatment periods, the properties of the soil were evaluated. The experimental data reveals that electrokinetic techniques could offer a low cost. rapid solution to treat saline soils. The removal efficiency of sodium ions was found to be greater than 90% within a relatively short time period of 14 to 30 days, using low current and voltage systems. After 14 to 30 days, the degree of salinity and sodicity decreased to a very low or negligible level. The unconfined compression strength of the soil increased by between 30 % to 100% in 30 days of electrokinetic treatment indicating the improvements in the physical properties, especially in the stress-strain characteristics of the soil. The liquid limit (LL) and plastic limit (PL) increased at the cathode.
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  • Description: 2003000726

Modification of the properties of salt affected soils using electrochemical treatments

- Jayasekera, Samudra, Hall, Stephen

  • Authors: Jayasekera, Samudra , Hall, Stephen
  • Date: 2007
  • Type: Text , Journal article
  • Relation: Geotechnical and Geological Engineering Vol. 25, no. 1 (2007), p. 1-10
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  • Description: In this project, an in situ soil treatment technique using the principles of electrokinetics was tested using laboratory experimental models in order to identify the potential of this approach in modifying and reinstating the physical properties of salt affected soils. Experiments were conducted in the laboratory using saline-sodic soils collected from two salt affected regions in central Victoria, Australia. Soil specimens were compacted in glass tanks to reproduce in situ density and in situ water content. Using mild steel electrodes inserted into the soil, a direct current was passed through the soil under a constant potential gradient of 0.5 V/cm for a period of 14 days. In separate experiments, distilled water and a saturated lime solution were introduced to the soil via the anode over this experimental period. It was observed that the soil dispersion, otherwise known as soil sodicity (measured as ESP - Exchangeable Sodium Percentage and SAR - Sodium Absorption Ratio) decreased by up to 90% in most regions of the soil between the electrodes. The compressive strength of the soil increased in excess of 100% with electrokinetic treatment alone while the lime-enhanced electrokinetic treatment led to an almost 200% strength increase. The liquid limit and plastic limit of the soil increased causing the plasticity index to decrease, indicating increases in soil compressive strength and workability. These results indicate the potential of this technique for improving the physical properties of salt affected soils both effectively and efficiently, and in particular gives hope for the remediation of salt affected land for infrastructure management and development. © Springer Science+Business Media, Inc. 2006.
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  • Description: 2003004772

Dry mechanochemical conversion of SrSO4 to SrCO3

- Setoudeh, N., Welham, Nicholas, Azami, S. M.

  • Authors: Setoudeh, N. , Welham, Nicholas , Azami, S. M.
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Journal of Alloys and Compounds Vol. 492, no. 1-2 (2010), p. 389-391
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  • Description: The effect of milling time on the dry conversion of celestite, SrSO4, to SrCO3 using sodium carbonate in a planetary type ball mill was investigated. After milling, the powders were leached in distilled water at room temperature and the solids then washed with 1 N HCl to separate the products. X-Ray diffraction analysis showed that SrSO4 started to transform to SrCO3 within 10 min of milling and the extent of conversion increased with milling time reaching >90% after 30 min. A <99% conversion of celestite to SrCO3 was obtained in 30 min by increasing the molar ratio of Na2CO3:SrSO4 to 1.3:1. © 2009 Elsevier B.V. All rights reserved.

Grab sampling for underground gold mine grade control

- Dominy, Simon

  • Authors: Dominy, Simon
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Journal of The South African Institute of Mining and Metallurgy Vol. 110, no. 6 (2010), p. 277-287
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  • Description: Geologists in some underground gold mines collect grab samples from broken ore piles or trucks as a method of grade control. It is often known as muck sampling. Generally, the goal of grab sampling is to try and reconcile the mined grade at the ore source to the predicted grade and/or predict the mill feed grade. The mass of the sample collected is limited by health and safety issues, as well as by the capacity of the laboratory to process the samples within a given time frame. In general terms, grab sampling is known to be problematic because samplers tend to oversample the fines, and/or pick out high-grade fragments; surface sampling of piles does not test material within the pile; muck piles in development drives/faces are likely to be zoned due to the blasting sequence; high or lowgrade material may preferentially segregate in the pile during mucking; the five per cent mass reject size of the material in muck piles is very large from underground blasting; some correlation usually exists whereby the larger fragments are enriched or depleted in the critical component of value; and the average error made in estimating the true stockpile grade is likely to be high. The method is prone to chronic fundamental sampling, grouping and segregation, delimitation, and extraction errors. Substantial warnings must be given about the use of grab sampling for grade control in gold mines. The method may appear to work sometimes, which can be attributed to a fine gold particle sizing and more disseminated distribution. As with all sampling methods, its appropriateness must be determined by ore characterization and heterogeneity testing to ensure the method suits the ore type. © The Southern African Institute of Mining and Metallurgy, 2010.

Ball milling induced reduction of SrSO4 by Al

- Setoudeh, N., Welham, Nicholas

  • Authors: Setoudeh, N. , Welham, Nicholas
  • Date: 2011
  • Type: Text , Journal article
  • Relation: International Journal of Mineral Processing Vol. 98, no. 3-4 (2011), p. 214-218
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  • Description: The reduction of celestite concentrate to SrS using Al has been shown to be induced by mechanical activation. A thermodynamic appraisal showed that the reaction between SrSO4 and Al is highly exothermic and should be self-sustaining. XRD analyses showed that reaction started only after milling for an induction time of 30-35 min, after induction only product peaks were present. Increasing milling time up to 60 min had no significant effect other than refining the crystallite size. The aluminium product was not Al 2O3 as expected but mixed phases such as Sr 3Al32O51, SrAl4O7 and SrAl2O4 which were thought to be formed by an adventitious oxidation process. © 2010 Elsevier B.V. All rights reserved.