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By N Collins, A Woodley, A N. Danoucaras, C McCombe, N C. Kunz

Over the past decade, the mining industry has come to recognise the importance of water both to itself and to others. Water accounting is a formalisation of this importance that quantifies and communicates how water is used by individual sites and the industry as a whole. While there are a number of different accounting frameworks that could be used within the industry, the Minerals Council of AustraliaÆs (MCA) water accounting framework (WAF) is an industry-led approach that provides a consistent representation of mine site water interactions regardless of their operational, social or environmental context that allows for valid comparisons between sites and companies.The WAF contains definitions of off-site water sources and destinations and on-site water use, a methodology for applying the definitions, and a set of metrics to measure site performance. The WAF is comprised of two models: the input-output model, which represents the interactions between sites and their surrounding community, and the operational model, which represents on-site water interactions.Members of the MCA have recently adopted the WAFÆs input-output model to report on their external water interactions in their Australian operations, with some adopting it on a global basis. To support this adoption, there is a need for companies to better understand how to implement the WAF in their own operations. Developing a water account is non-trivial, particularly for sites unfamiliar with the WAF or for sites with the need to represent unusual features. This work describes how to build a water account for a given site using the input-output model, with an emphasis on how to represent challenging situations.CITATION:Woodley, A, Danoucaras, A N, McCombe, C, Kunz, N C and Collins, N, 2013. A robust methodological approach for mine site water accounting, in Proceedings Water in Mining 2013 , pp 335-342 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

Selection of mining methods, stope dimensions and stoping sequences is usually based on comparisons with other similar orebodies or rocktypes. Rock mechanics principles assist the process, which can be further improved by application of rock mechanics' models - in particular, computer based stress analysis techniques. These models vary in capabilities and potential application but, basically, can be subdivided into techniques which only model the surface of excavations, and those which model the total volume to be analysed. To address the wide range of geometries, stoping methods and sequences, and geomechanical environments at Mount Isa Mines, a number of models have been developed. By presenting examples of their actual and potential application it is demonstrated that appropriate use of these techniques will assist in the determination of mining parameters and improve ore recovery. Examples presented cover sequencing in tabular and massive orebodies, location of shafts and shaft pillars, and backfill and hanging-wall stability. It is concluded that surface techniques are more appropriate for regional analyses and volume techniques are more suited to analyses of detailed, local geometry. Colour computer graphics should be an integral part of data preparation, and results interpretation and Presentation.

Jan 1, 1986

By B A. Webler, P Su, P C. Pistorius

Advanced high-strength steels (AHSS) typically have much higher aluminium concentrations (by an order of magnitude or more) than conventional low-carbon aluminium-killed steels. The resulting lower oxygen activity at the steel-slag interface changes the kinetics and thermodynamics of steelslag reactions. Previous work showed that the rapid transformation of alumina inclusions to spinel inclusions, and spinel to periclase, occurs because of the relatively high concentration of dissolved magnesium. In this paper, experimental results on nitrogen removal by ladle slag are compared with predictions based on the available thermodynamic databases. As in previous work, the kinetics was modelled by assuming mass transfer control, with steel or slag mass transfer limiting. The results show that significant removal of nitrogen by steel-slag reaction is possible.

Aug 21, 2024

By N A. S Webster

The reaction sequences involved in the formation of iron ore sinter phases were determined using in situ synchrotron-based X-ray diffraction. Experiments were carried out using a synthetic sinter mixture containing 77.36 per cent Fe2O314.08 per cent CaO, 3.56 per cent Si.O2 and 5.00 per cent Al2O3 corresponding to a basicity of ~4. The alumina content represents the upper level of alumina concentrations measured in phases formed in industrially produced plant sinter. Data were collected during heating of the sample to 1350°C under an atmosphere of 0.5 per cent O2 in N2, equivalent to an oxygen partial pressure of 5 × 10-3 atm. This temperature was sufficientto ensure melting. Data were also collected on cooling of the sample back to room temperature to examine recrystallisation of phases from the melt.Results showed the sequence of reactions initially involved the formation of calcium ferrite phases C2F and CF. These subsequently reacted with the silica and haematite leading to the solid state formation of SFCA and SFCA-1. SFCA and SFCA-1 were the last phases to form in the system and were both stable up to ~1260°C. Above ~1260°C, melting of the SFCA phases and reduction of the remaining haematite occurred producing the assemblage magnetite + melt.During cooling, both SFCA phase types recrystallised from the melt initially coexisting with magnetite until secondary haematite formed. This is the fi rst study to demonstrate that both SFCA and SFCA-1 are precipitated from the melt during cooling of iron ore sinter. Future work will extend the range of compositions studied to examine the effect of basicity and alumina concentration on the phase assemblages as a function of temperature and oxygen partial pressure.

Jul 11, 2011

By J Emslie

Newmont AustraliaÆs Callie Underground Gold Mine is located on the Dead Bullock Soak Mining Lease, approximately 600 km NW of Alice Springs, NT, in the Granites-Tanami Goldfield. Dead Bullock Soak is part of NewmontÆs Tanami Operations, which also include the Granites Gold Mine and processing plant, Groundrush Open Pit and Tanami Mill. Callie is a world class Proterozoic gold deposit; production to date is in excess of 1.7 million ounces, with an additional Proved and Probable reserves at the end of 2002 of 10.8 Mt at 6.3 g/t. Gold mineralisation at Callie occurs in thin (1 - 30 mm) steeply dipping quartz-chlorite sheeted vein system that cuts across a 40¦ plunging folded sequence of medium to fine-grained metasediments. While the vein system is highly continuous, the gold distribution is highly variable and is controlled by the interaction of lithology, alteration, structure and vein density. The mineralisation is commonly coarse-grained and has a relatively high nugget effect, consequently the orebody is problematic to estimate and shows a high degree of sensitivity to drill hole density. Resource modelling at Callie is an example of a geologically driven model that has evolved with increasing data and understanding. Lithological and structural models are employed to define domains within which the grade estimation is undertaken using multiple indicator kriging. This gradual model evolution impacted greatly on the selection of the mining method. Uncertainty in the estimation of the orebody was a significant factor that led to sublevel open stoping with cemented aggregate fill being adopted as the mining method to improve extraction selectivity. Callie often shows strong positive reconciliation compared to the mill. The mine geologistÆs face the challenge of limiting the degree of underestimation of the core of stopes whilst ensuring that stope boundaries are not conservative. This can only be achieved through the mapping of subtle geological features in order to confirm the orebody model. The increased use of the geological mapping has improved our understanding of the controls on mineralisation and has been extended into the development of new models for near mine underground exploration.

Jan 1, 2003

By N Winkelmann

Underground coal heating is a significant hazard in some coal mines. The broad principles of how underground coal heatings occur is reasonably known, however the technique for locating the heatings in often inaccessible goaf has been proved to be difficult. Since 2002, CSIRO, with the support of the Australian Coal Association Research Program (ACARP) has been undertaking investigations to apply and develop innovative surface-based radon technique for locating the underground heatings in Australia. This paper presents the progress of the investigation.

Jan 1, 2005

By Hoberg H, Schneider FU

The stability of suspensions can frequently be controlled only by the use of supplementary polymeric agents. Such methods date back to the time of the ancient Egyptians, who used natural rubber as a deflocculant for carbon black in the manufacture of ink (Anon, EncyclopediaBritannica, 1968). Since the development of synthetic polymers in the 1950s they have been deployed in all manner of applications. Indeed the mining and paper industries as well as industrial or communal waste water treatment plants are largely dependent on flocculants which make a major contribution to the relief of the environment. As some of the polymers used are carried out from the process via purified water, problems can emanate from the application itself as long as no reliable data is available as to the exact whereabouts of the polymers and their impact on the biosphere. In order not to invade other systems, they would have to be biologically degradable which has not, until now, been confirmed (Blockhaus, Sequaris and Schwuger, 1991; Schumann, 1991). It has, however, previously been demonstrated (Hoberg et al, 1990) that when process water circulates in mineral processing operations, residual amounts of polymeric flocculants can have extremely adverse effects on the selectivity of flotation processes. The adsorption behaviour is consequently one of the most important considerations in the development of new polymers, the aim being to minimise the amount of non-absorbent matter. The objective of the investigations carried out on ampholitic synthetic polymers of high molecular weight to be reported on here was to permit the connection between settling index and adsorptivity to be characterised in greater detail. As the level of knowledge concerning flocculation and polymer adsorption in real systems is still limited in spite of numerous practical and theoretical studies in this field, the experiment was designed to be relatively broadly-based. As well as investigating various raw materials, an attempt was made to compile results on the influence exerted by different surface charges.

Jan 1, 1993

By E Garbarino, P Molina, V Badino

Given the ever increasing quantity of construction and demolition waste (C&DW), one of the most challenging issues presently facing policymakers and public administrators in Italy concerns how to organise and manage collection and recycling and to understand whether and to what extent recycled aggregate can complement natural building aggregates in a sustainable supply mix (SSM). The paper presents the results of a research aimed at analysing energy and environmental implications of the C&DW recycling chain in the administrative territory of Provincia di Torino in northern Italy. In respect of a population of about 2.25 million inhabitants, the annual production of C&DW in the area under study is 1.8 Mt. A combined geographical information system (GIS) and Life Cycle Assessment (LCA) model was developed, paying attention to the geographical location, land use, transportation network and avoided landfill: crucial issues for sustainable planning and management. Around 90 recycling plants were classified according to the size, typology (stationary, semi-mobile and mobile) and physical- mechanical characteristics of the recycled aggregate. Under different assumptions relevant to the delivery distance, and considering the typology and grade of recycled aggregate, as well as local availability of natural aggregates, it was possible to evaluate the geographical coverage of aggregates demand and to use LCA in order to identify and quantify energy and environmental indicators.

Jan 1, 2009

By E Kabwe, E Chanda, M Karakus, S Akdag

The Convergence Confinement Method (CCM) is one of the frequently used methods that considers the ground response to the advancing tunnel face. The CCM analytical solutions represent stress relaxation on circular tunnel walls in a rock/soil media. The CCM analytical solutions is based on circular tunnel geometry and consider a hydrostatic stress field in a homogeneous isotropic rock mass condition. However, noncircular tunnel geometries, non-hydrostatic stress field, staged excavation process in a discontinuous anisotropic non-linear rock mass conditions are usually ignored in these analytical solutions. In this paper, we investigate the performance of the existing CCM analytical solutions developed for elastic and elastoplastic ground behaviour for circular tunnels. For this purpose, a finite difference analysis is conducted to compare the analytical results with the results obtained from Finite Difference Method (FDM) for a chosen rock mass condition. Results obtained from the investigation shows that floor, crown and wall displacement are 30%, 10% and 23% more, respectively, in a horse-shoe relative to a circular tunnel. This indicates that the application of analytical formulation tailored for circular tunnels would lead to inaccurate quantification of wall convergence in horseshoe-shaped tunnels. CITATION:Kabwe, E, Karakus, M, Chanda, E and Akdag, S, 2018. Investigating the tunnel closure using convergence confinement method and 2D plane strain finite difference analysis, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 152–159 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By D Duan

In this study, aimed at two kinds of ore (lump ore and iron ore fines) and four types of Australian iron ore resources (haematite iron ore, Mara Mamba iron ore, limonite iron ore, and mixed iron ore, such as Newman, MAC, Yandi and Pilbara iron ore), the physical and chemical properties and high-temperature properties were investigated in detail, to master their behaviour and effects in sintering, blast furnace, and non-blast furnace processes. Then, according to the individual properties of Australian iron ores, Chinese domestic iron ores and Brazilian iron ores, etc, the optimisation of ore-proportioning for sintering, blast furnace, and non-blast furnace processes was studied based on the interaction of the individual iron ores and their complementary properties, and the corresponding tests were carried out. The test work results indicated that this method not only improved the technical and economic indexes of sintering, blast furnace, and non-blast furnace processes, but also increased the addition of Australian iron ore. All of these provide the theoretical basis and technical support for highly effective use of Australian iron ore resources in iron and steel enterprises in China.

Jul 11, 2011

By D Giddings, S A. Silvester, S Pickerin

Underground fires represent a constant threat to the safety of underground personnel. Miners in the immediate vicinity may face intense heat, blinding smoke, toxic fumes, fall of ground and other direct effects of a fire. However, the vast majority of victims never actually see the fire, and are overcome either by deadly fumes in the ventilating current or by asphyxiation. The mine ventilation system, which maintains a sustainable atmosphere to the working places, can transport products of combustion with equal efficiency. Miners who are remotely situated from a fire may be forced to evacuate considerable distances, through dense smoke and fumes, or even become cut-off from escape. Additionally, miners may become confused by unfamiliar ventilation characteristics caused by fires. Conveyor belts are widely used for transporting minerals in mines as well as in many other industrial situations. Because they contain large amounts of polymeric materials their use in certain environments, especially coal mines, but also in steel works, power stations and other enclosed areas must be controlled to minimise the fire risk. Over last nine years there have been 60 fires in underground mines in the UK alone and that of these, half have been associated with conveyors. This paper summarises the results obtained from a recent research project that has developed a preliminary computational thermal and fluid dynamic model to represent the spread of flame along a typical conveyor belt used in UK deep coal mines. The results of these models have been calibrated against a series of experimental tests performed within a surface fire test gallery. An improved knowledge of the burn characteristics and rate of release of the products of combustion from conveyor belt fires will assist in the development of better fire detection and fire fighting techniques.

Jan 1, 2005

By A Winchester, D Grant

The massive 1100 Orebody in Mount IsaÆs X41 Copper Mine has been extracted over the last 40 years form north to south utilising sublevel open stoping methods.De velopment has continually stepped ahead of production to provide access to new primary stoping blocks. The remaining secondary pillars contain stopes with one, two or three fill mass exposures and were constrained by access requirements and stope extraction turnaround time.The remaining southern mining areas consist of large 40 m wide by 300 to 400 m long east-west transverse pillars that have been left to provide access for ventilation and service requirements. Three large transverse cross-cuts or transverse pillars û 4180 x/c, 4010 x/c and the Panel pillar now remain. The 4180 x/c was the last major transverse pillar to be successfully broken.This transverse pillar is being extracted in a retreating sequence, creating 3SLOS stopes due to the surrounding backfilled stopes.In recent years the extraction of the first, and most critical, stopes in the transverse pillars have resulted in large changes to the induced stress field. This paper describes the extraction of the 1.1 million tonne stope P418 in the 4180 x/c pillar.T echnical challenges that were faced and how they were overcome to allow for the successful extraction of the stope are described.Critical to the success of the P418 stope extraction were the rehabilitation methodology used; extraction strategy modifications to address deteriorating ground; mass firings with multiple directional changes; managing the exposure of backfill of variable strengths; and geotechnical monitoring prior to, during and after extraction.

Jan 1, 2005

By A Wanninayake, E Novello, I Gillani

A residue storage facility (RSF) was designed to cater for Davidson Creek Area and Robertson Range Area operations under the FerrAus Pilbara iron ore development project in the Pilbara Region, Western Australia. Annual ore production was about 15 million tonnes over a period of up to 15 years. The RSF was designed to handle a tailings production rate of 2.2 Mt/a over the project life with ability to be expanded at a later date. The composition of tailings was predominantly -45 ¦ material with some spiral reject material. The fraction of solids was expected to be between 40 per cent and 50 per cent solids by weight.The RSF was designed as an above ground storage facility, integrating with a mine waste dump planned close to the selected RSF site. This integration helped to increase the stability of the RSF embankment and to reduce the construction cost. The main source of construction material for the remaining part of the RSF embankment was selected to be mine waste. The RSF was designed to be constructed in stages by considering the availability of mine waste according to the mining schedule. The use of mine waste for construction of RSF embankments has several benefits over use of borrowed material. These include less construction costs and less disturbances to the environment, by minimising borrowed areas and waste dump footprints.CITATION:Wanninayake, A, Novello, E and Gillani, I, 2013. Effective use of mine waste in the design of a residue storage facility, Pilbara region, Western Australia, in Proceedings Iron Ore 2013 , pp 39-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By J Rutter, E Amini, D La Rosa, N Beaton, M Scott, F Faramarz, L Keeney

Anglo American’s Los Bronces copper mine in Chile has been conducting detailed assessments investigating value adding options for their asset. The mine has conducted several detailed Mine-to- Mill and Grade Engineering studies to investigate increased throughput and head grade and to quantifying the impact of these approaches across the life of mine. CRC ORE has two key technologies namely Grade Engineering and the Integrated Extraction Simulator. These two technology suites have been combined to understand the technological landscape and associated value drivers suitable for application at Los Bronces. Detailed ore characterisation test work was conducted to:  measure and spatially model the propensity of ores to naturally deport and  develop customised blast models for Mine-to-Mill and Grade Engineering evaluation The outputs of this work were utilised to develop a block model populated with a range on new Grade Engineering and blasting parameters suitable for scenario analysis. To facilitate scenario analysis a high-fidelity value chain model of the Los Bronces operation from blasting to concentrate production was built in IES. IES was combined with sophisticated analytical tools such as Neural Networks to develop and reconcile a fully integrated value chain. The value chain model made it possible to simulate in IES all available blocks in the block model to predict throughput and grade changes for different strategic scenarios. The scenario analysis was run across 24 strategic combinations of Mine-to-Mill and Grade Engineering and comprised several million simulations. The scenarios investigated each technology independently and jointly to provide an attributed block model that can feed forward into technoeconomic modelling to determine optimal execution strategies for the mine. This paper presents the first published study combining Grade Engineering and IES to provide mass simulation capability to investigate strategic options for a mining asset.

Nov 10, 2020

The Electrolytic Refining and Smelting Company of Australia Limited (ER&S) operates a copper smelting and refining plant and is situated close to the heart of the highly industrialised area of Port Kembla. In March, 1982 the Company entered into an undertaking with the State Pollution Control Commission (SPCC) to monitor ambient levels of sulphur dioxide (S02) gases present in the atmosphere in the surrounding urban area. Despite the use of a 200 metre high stack for dispersal of the smelter waste gas stream at ER&S, two local suburbs, Warrawong and Primbee were experiencing on occasions high ambient concentrations of S02 resulting in discomfort to local residents. In late March 1982, ER&S installed a highly advanced S02 monitoring system to continuously monitor the levels at Warrawong. The system was extended to include S02 monitoring at Primbee in November 1982, and further extended in June 1983, to include an input of meteorological data. Initially the system was designed to monitor and react to high concentrations of S02 at either of the two monitoring stations. Currently however, refinement is taking place to allow a predictive nature to be built into the system such that it not only reacts to an adverse situation but can predict weather patterns likely to cause high concentrations and thus avoid these events. The entire system is still undergoing a growth and development period, however the results obtained to date are pleasing to both the Company and the SPCC.

Jan 1, 1984

By C Li, K McDonald an, T Nicholson, C Brown

The relative reactivities of chars prepared from different coal samples at temperatures in the range 500 to 1150¦C were determined by measuring the rates of metallisation of a standard ilmenite concentrate. The results have been interpreted in relation to different measured physical and chemical properties of the chars. Char reactivities were found to correlate with the maximum specific surface area (SSA) of the chars, obtained from plots of SSA versus temperature. Weathering of coal samples gave higher reactivities which correlated with higher SSAs. Experiments using recycled chars showed that the high internal SSAs developed during earlier reduction reactions provide no benefit in terms of increased metallisations. The important role of char hydrogen contents in controlling low temperature metallisation rates was demonstrated. Chars prepared from different rank coals had the same hydrogen content when prepared at the same temperature. Ilmenite metallisation rates had a linear dependence on the hydrogen content of the chars. Large differences in the slopes of the metallisation versus H2 content curves for different chars were interpreted in terms of SSA variations and catalysis of the gas reactions by dispersed metallic iron particles in the chars. A simple test based on magnetic separation of the char was shown to give an indication of enhanced reactivity due to contained metallic iron.

Jan 1, 2001

By García B., Wolff E.

The pellet qualities primarily depend upon the thermal profile and gaseous environment during induration. During the induration of the pellet, it undergoes physical as well as chemical changes. Physical changes are mostly due to sintering and chemical changes are due to carbon burning inside the pellet. The effect of carbon on sintering is investigated on a single pellet scale using an optical dilatometer. Sintering is a complex process that involves transportation through various mechanisms. Sintering is quantified in terms of sintering ratio and the kinetic parameter, exponent ‘n’, under isothermal conditions is deduced using the power law equation. The value of n can be used to estimate the sintering mechanism at different isothermal temperatures. Also, the activation energy is calculated using the empirical Arrhenius equation. The activation energy of 0 per cent coke and 1 per cent coke-containing pellets are 531.0 kJ/mole and 552.6 kJ/mole respectively. The order of magnitude of activation energy suggests the same mechanism in both cases. Although the mechanism of sintering is the same, 1 per cent coke-containing pellet sinters more at any isothermal temperature.

Jun 17, 2024

By Whiteman P. C, Stacey G. S, Hunter G. D

Processing of lead-zinc and copper ores by Mount Isa Mines Limited produces large quantit- ies of concentrator tailings waste which is pumped as a slurry to special dams where the solids are allowed to settle and dry out. These areas are unattractive and show no signs of encroachment by plant life even though the surfaces of some dams have remained undisturbed for more than a decade. During 1970 Mount Isa Mines Limited commenced a long term research program in conjunction with the Department of Agriculture, University of Queensland to deter- mine possible methods of establishing a plant cover on this material. Research has defined the major factors limiting plant growth in the tailings medium. Modification of the edaphic conditions through fertilizer inputs, particularly of phosphorus and nitrogen, and alteration of "soil" physical properties by incorporation of mulching mater- ials, provided conditions which allowed plant growth. The outstanding "soil" amendment treatment was incorporation of fly ash, a waste product of the company's coal fired power stations. A range of crop and pasture species have been selected which have grown well with adequate irrigation under the amended conditions in the field. Further research is assessing a range of native plant species and agronomic techniques to provide a stable plant cover on the tailings dams.

Jan 1, 1974

Blasting is an essential component of most mining operations, and is used to reduce the rock mass to a workable size distribution, as well as to create stable openings and pit walls. Frequently, there is little difference between the designs of blasts to achieve these two functions, though more advanced operations have developed different designs for these very different functions. To assist in the appreciation of how blasting practices can impact on the stability of rock openings and pit excavations, this paper reviews the role of high pressure explosion gases on final block stability. It is assumed that the stability of all surface and underground excavations are, to a greater or lesser extent, controlled by the interaction between discrete rock blocks. Typically, these blocks will be defined by either natural, or excavation induced, jointing.

Jan 1, 1999

By R N. Lamb, A N. Buckley

Experiments have been carried out to establish whether time-of-flight secondary ion mass spectrometry (ToF-SIMS) is able to differentiate monolayer and multilayer coverage of thiol collectors on sulfide minerals. The systems investigated were those for which x-ray photoelectron spectroscopy is able to provide an independent determination of the extent of coverage, and included diethyldithiophosphate (DTP) and 2-mercaptobenzothiazole (MBT) on chalcocite, DTP on Ag2+MS prepared by sulfidising metallic silver, and isobutyl xanthate (BX) and MBT on galena. For monolayer adsorption of MBT on chalcocite, peaks from MBTû but not Cu(MBT)û ions were evident. For multilayer coverage, Cu(MBT)2û ions were clearly present, notwithstanding the fact that other data had identified the principal multilayer species as Cu(MBT). For adsorbed DTP on copper and silver sulfides, DTPû and metal(DTP)Hû peaks were observed for monolayer and multilayer coverage. Although the multilayer species was expected to be predominantly metal(DTP), metal(DTP)2û ions were evident for multilayer (but not monolayer) coverage. For the PbS/BX system, intact Pb(BX)2 or Pb(OH)BX ions were not detected for multilayer coverage, although Pb-containing ions heavier than PbBX were. Indeed, for all the systems studied, ToF-SIMS was able to differentiate monolayer from multilayer coverage. In general, however, the SIMS evidence alone might not be sufficiently definitive to effect the differentiation. In the case of collector adsorption on copper and silver sulfides, if the multilayer species detected had been the metal monothiolate only, and had not involved the formation of some metal dithiolate, then ToF-SIMS might not have been able to provide an unequivocal differentiation of the two coverage conditions.

Jan 1, 2005