Search Documents

By Z Endut, T F. Ng, G H. Teh, J H Abdul Aziz

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Gold mineralisation at the Penjom gold deposit in the Central Belt of Peninsular Malaysia is hosted in structurally-controlled quartz-carbonate veins that display a variable degree of overprinting events under a ductile-brittle regime. Mineralised veins are categorised into two main types: shear and extension veins. Shear veins are interpreted as forming during the fold and thrust episode (D2 event) along the bedding and the Penjom Thrust ore zone. The shear veins are associated with discordant extension veins. In addition, NE- to NNE-trending splays and Penjom-Thrust-parallel reverse-dextral and locally NNW to N–S reverse-sinistral faults overprint earlier vein events, forming a new episode of extensional veins during the D3 event. This is mostly at the fault contacts of intrusives, either as shallow-dipping or vertical-sheeted stockwork or brecciated veins. At least two episodes of faulting comprising D4-D5 are evident, which postdates the main episodes of veining and mineralisation. This is indicated by a series of late episode N–S-trending sinistral and oblique to normal faults that transect and displace the Penjom Thrust and the folded footwall sequence at low angles, and are interpreted to be responsible for intensive vein deformation along the Penjom Thrust and displacement of the orebody. Structural interpretations of mineralised veins suggest that the veins were formed under a compressional to transpressional regime, with later post-vein displacement in a transtensional to extensional regime. Vein formation in response to deformation observed at Penjom reflects regional structural deformation within the Central Belt of Peninsular Malaysia and specifically along the Bentong-Raub Suture zone.CITATION:Endut, Z, Ng, T F, Abdul Aziz, J H and Teh, G H, 2015. Style of veins in Penjom gold mine, Malaysia – implications for gold mineralisation and structural episodes, in Proceedings PACRIM 2015 Congress, pp 507–514 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By A Valero, G M. Mudd

There is active debate and research around the most suitable indicators to assess the sustainability of mining. The most common approach is to report a range of data for a given mine site (or less preferably, a company total), such as inputs, outputs, benefits and potential costs. The most popular protocol in use (and growing rapidly) is the Global Reporting Initiative (GRI). However, these measures are numerous and still do not allow a single over-arching indicator to be developed. Other measures, such as known mineral resources over time, do not account for critical challenges such as declining ore grades, increasing wastes and poorer quality ores or more difficult mineralogy. By adopting a thermodynamic approach to sustainability, through the concept of æexergyÆ, it is possible to incorporate into a single measure the effective quality of mineral resources. Exergy involves the assessment of the minimum energy costs involved in producing a mineral resource with a specific chemical composition and concentration from common materials in the environment. The exergy of a mineral resource is evaluated from mineralogic composition, concentration (or ore grade) and, of course, quantity, by multiplying the unit exergies with the tonnes of the resource produced (or consumed). Since exergy is a thermodynamic quantity (ie energy or joules), it is additive across different minerals, such as iron ore to gold to copper or even oil and gas or coal û making it an ideal indicator to assess mineral resource sustainability at the industry scale rather than the individual mine scale. This paper briefly outlines the theoretical basis for exergy, and then presents a range of commodity case studies showing the application of exergy to the Australian mining industry. Overall, the usefulness of exergy is clearly demonstrated for use as a broad indicator of the sustainability of mineral resources at the national or even global scale.

Jan 1, 2009

By R G. Jeffrey

The Northparkes, Endeavour 26 orebody is a porphyry copperûgold deposit and comprises a moderately to well jointed rock mass characterised by gypsum veining, the intensity of which decreases with depth. The top 480 metres of the orebody is currently being mined by block caving, the undercut dimensions measuring 196 metres in length by 180 metres in width. Continuous caving was never achieved after the completion of the undercut thus cave inducement techniques were sought to maintain caving so as to safely sustain production. The use of hydraulic fracturing as a cave inducement tool was successfully trialled in December 1997 using existing exploration boreholes located midway up the current lift. Subsequent fracturing campaigns have enjoyed various degrees of success and have yielded in excess of seven million tonnes of ore at a significantly lower cost than conventional cave inducement techniques. Monitoring of both the hydraulic fracture system and the rock mass response has provided considerable insight into the geometry, growth and influence of hydraulic fracture networks above the Northparkes block cave, and has initiated additional research into the use of hydraulic fracturing in other mining methods.

Jan 1, 2000

By C DahnTr-Lindqvist

The Kiruna mine produced about 19 Mt processed iron ore in 1999 using sublevel caving. General failure in the hangingwall has been widely studied and its mechanism is rather well understood. Failure in the footwall is more recent and not perfectly explained. Plane shear failure and Hoek and BrayÆs circular failure charts were successfully used to match the first surveyed failure surfaces. The footwall is not free yet but covered by a caved waste rock abutment whose exact behaviour is poorly known. Based on new field data and numerical models (FLAC), the following paper presents recent improvements in understanding the Kiruna mineÆs footwall failure process.

Jan 1, 2000

By M D. Uttarwar, R R. Yerpude

India is the world’s third-largest producer of coal and is endowed with the fifth-largest coal reserves in the world. Surface mining straddles the entire domain of the Indian coal mining industry, yielding over 88 per cent of production. With continually rising domestic demands, it has to shoulder the responsibility of sustaining the requisite increase in coal production and chasing commensurate stripping targets. Such an ambitious task calls for the deployment of smart technologies. In such a demanding situation, cast blasting of overburden has emerged as a promising alternative for enhancing production and productivity of dragline pits.The cast blasting technique reduces stripping costs significantly as it utilises the chemical energy of explosives in place of mechanical energy to move large volumes of overburden quickly. Proper application of cast blasting not only reduces overall mining costs but also increases coal production. This paper investigates and evaluates the potential of the cast blasting technique, with special reference to dragline pits employing the rehandle method of extended bench. The economic feasibility of the technique is also ensured under different scenarios so that considerable benefits would accrue to the individual surface coalmines. To underline the efficacy of the technique, different cast blasting models have been formulated under a range of operational and economic scenarios that resemble present day practices in India. In order to test for economic variability in the application of the technique, a risk analysis of all the formulated cast blasting models is performed using net present value.CITATION:Uttarwar, M D and Yerpude, R R, 2015. Potential of the overburden cast blasting technique in Indian surface coalmines – a modular approach and its financial implications, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 655–664 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J Player, R de Vries, E Villaescusa, R Hassell

Concerns regarding the uncertainty of stope dilution at MMG Dugald River Underground Mine led to a trial stoping program to acquire full-scale comprehensive geotechnical information and to test the validity of the geotechnical and mining parameters. Given that stope production drilling and blasting is a key parameter that influences dilution a detailed stope blast vibration project was implemented. The stoping trial consisted of 19 stopes, a combination of both sublevel open stoping and longitudinal and transverse stopes, of which five were monitored for blast vibrations.The blast vibration project utilised 20 triaxial geophones and five triaxial accelerometers installed in the hanging wall of five monitored stopes. For each stope fired, full blast waveforms were recorded along with detailed information of the blast design. Analysis of the blast vibrations used the Holmberg-Persson approach, with potential damage determined by the relative (Holmberg-Persson) K values.The project identified the benefit of parallel, breakthrough slot holes in reducing blast vibration damage. The results show that radial rings toeing or stabbing into the stope wall lead to higher vibrational energy yield which contributed to increased overbreak. Hanging wall overbreak, by comparison, with parallel, breakthrough blastholes with 1 m standoff, combined with lower density explosive charging (0.8 EP) and increased delays limited blast vibration damage. A number of ring burdens from 1.4 m to 2.5 m were monitored with no difference in terms of energy yield being identified. Changes to the stope drill and blast design are suggested to better control the large blast vibrations and recommendations from this project have been implemented into future mine design and planning.CITATION:Hassell, R, Villaescusa, E, de Vries, R and Player, J, 2015. Stope blast vibration analysis at Dugald River Underground Mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 221–232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By R K. A Taylor

The growth in production of beneficiated ilmenite products has been one of the most significant trends in the titanium feedstock industry over the past 30 years. In this period, the production of titanium slag and synthetic rutile has grown five-fold to the point where these products represented 56 per cent of total feedstock production in 2000. Additional production capacity is being proposed as the core component of new feedstock supply projects presently under consideration. A high proportion of these products is based on technologies for which the inherent quality of the is an essential factor. Location specific factors also play a large part in determining the cost of production. As the demand for such products grows, and the availability of favourably located sources of ilmenite of suitable quality declines, it can be expected that existing beneficiation technologies will become increasingly constrained. Existing beneficiation technologies, and those which have been developed, but are not yet commercially applied, are reviewed. Future issues which are likely to impact on the cost effectiveness of these technologies, or the quality of final products, are identified. These factors suggest directions for development of ilmenite beneficiation technologies to achieve economic production of the quality of feedstocks which will be demanded by the TiO2 pigment industry in the future.

Jan 1, 2001

By J Hutchings

An essential component to the management of any process is the measurement of key parameters, used to monitor, control, and provide the feedback necessary for improvement. This paper discusses how data collection and analysis can provide a better understanding of the blasting process, as well as additional control and improved outcomes.The drill and blast process involves the generation and use of information at a number of levels. Comparison of historical parameters and results provides a starting point for the development of ongoing blast designs and a baseline against which future results can be compared. The collection of data during implementation provides a quality assurance/quality control (QA/QC) function where potential defects (such as under-drilled or over-charged holes) can be rectified prior to firing. Actual quantities and production rates allow the development of realistic plans and schedules, rather than using inaccurate estimates and targets that lead to unscheduled changes to equipment paths. Over?the past several years there have been a number of technological advances in data collection technology. Drill monitoring instrumentation on blasthole drills provides location information and feedback on rock properties as drilling occurs. Hand held ‘data logger’ technology has also overcome the challenges of working on the bench, such that blasthole measurements can be collected and forwarded directly to the explosive truck. Mine sites are becoming wireless network-enabled allowing the seamless data transfer from the field back to the office, in near real time, as that information is collected. Great strides have also been made in the development of drill and blast software systems which are more user friendly, and yet provide far greater capability to manage the quantity of data generated. The blasting process is critical to the overall mining process and the delivery of a successful blast outcome requires that the blasting process be ‘in control’. The measurement of key parameters can provide the data with which to measure and maintain control of blasting, and allows the validation of performance improvement measures and identification of improvement opportunities.

Nov 8, 2011

By H R. Pein

"The Corridor Sands deposit is situated approximately 190 km north east of Maputo, Mozambique adjacent to the paleo-mouth of the Limpopo River. This deposit is one of the worldÆs largest known economically viable resource of titanium, accounting for approximately one third of the global resource. As part of the pre-feasibility and feasibility study for development of the Corridor Sands project, various geological and geotechnical investigations were undertaken, selected results of which are presented in this paper. These investigations have enabled a detailed understanding of the material characteristics of the orebody as well as the tailings materials, such as the fines, to be developed. These material characteristics have had a significant impact on the selection of the mining and disposal methods currently being implemented."

Jan 1, 2001

By E R. Ramanaidou, M A. Wells

Asian steel mills are demanding iron ore with specific chemical, mineralogical, metallurgical and environmental properties to warrant that the ore is of the greatest quality. As a result, a toolkit of analytical techniques becomes important. Hyperspectral analyses of iron ore cores and chips using a HyLogging™ system are now routinely undertaken by BHP Billiton Iron Ore in Western Australia for banded iron formation-hosted iron ores and channel iron deposits to better characterise their iron ores. Objective information can now be expanded by adding new sensors. The current HyLogging™ system provides point analysis reflectance spectra and a red–green–blue high-resolution image, while recent developments, such as hyperspectral imaging using the Corescan system, now provide full spectral image and surface topography. The addition of Raman spectroscopy provides the ability to detect and quantify quartz and magnetite (or maghemite) and cross validate hyperspectral information on hematite and goethite and aluminium substitution in the iron oxides. Micro-X-ray fluorescence mapping also adds chemical information appropriate for cross validation with the aforementioned methods. This paper demonstrates the value of combining these techniques for an optimum characterisation of iron ore.CITATION:Ramanaidou, E R and Wells, M A, 2015. A new toolkit for iron ore characterisation, in Proceedings Iron Ore 2015, pp 587–590 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Waterhouse J. D, Harris B. M

This paper briefly describes the construction in 1979/80 of a 70m deep trial open pit coal mine near Bowmans S.A. and describes more fully the hydrogeological aspects of the exercise. The primary purpose of the Trial Pit was to provide a large sample (700 tonnes) of coal for combustion tests to be carried out in West Germany and the United States of America. Consideration was given to obtaining the sample of coal by drilling and by shaft sinking as alternatives to open pit methods. It was expected that economic mining of the deposit on an operational scale could only be achieved by open cut methods and it was recognised that major uncertainties existed in planning such a mine in the deep unconsolidated multi-aquifer deposit. It was therefore elected to obtain the bulk sample by constructing a trial open pit, which would be closely monitored to provide as much data as possible for future planning of a full scale mine. The dewatering of the Trial Pit was achieved using 26 deep pumping wells, assisted in the later stages by several hundred well points. This was probably the largest dewatering project currently in operation in Australia.

Jan 1, 1981

The Mt Sinivit gold project is located approximately 50km SSW of Rabaul in the Baining Mountains of the Gazelle Peninsula, East New Britain Province. The deposits were discovered in mid- 1983 and form part of a larger 26km long zone of variably aurif- erous quartz veining. There are no surface indications or previ- ous records of any prospecting activity or production from the region. The Mt Sinivit deposits consist of a series of oxide and sulphide reserves and resources contained in the Wild Dog (South- ern, Central and Northern oxide zones; Northern sulphide zone) and Kavursuki veins. The proposed exploitation of the oxide reserves by a series of small-medium sized open pits has been fostered by the PNG Department of Mining & Petroleum (DMP) as part of a government policy to encourage the development of a small-medium sized mining industry in the country. The aim of this paper is to document the steps and procedures involved in obtaining the grant of a Mining Lease emphasising the time and the expenditures required during each step of the approvals process for the Mt Sinivit project.

Jan 1, 1997

State ownership of minerals results in domestic legislation regulating mining operations. The mining industry today is dominated by a number of transnational companies, each subject to internal and external pressures for a more responsible approach to resource management. Thirty to 40 major companies are responsible for the bulk of the worldÆs mineral production with the balance coming from state-owned, second tier and junior companies and from artisanal miners.Mining companies operating within competitive commercial environments formerly focussed on mineral production. Companies worked to standards and expectations then current which largely failed to recognise the impact of mining activities on community interests. The mining industry acquired a reputation for arrogance, and for placing profitability ahead of issues considered equally or more important by local communities. Current perceptions continue to reflect disquiet about industry attitudes towards traditional land-owners and access to their lands, to environmental contamination, handling and storage of waste materials, utilisation of water and electricity, and to rehabilitation of worked out areas. Major international mining companies concerned at continuing criticism sponsored a series of initiatives with the objective of providing guidance on working harmoniously within the community. Industry commissioned studies, performed through the agency of disinterested parties, resulted in May 2002, in a Declaration being issued at an International Conference in Toronto. The Declaration was based on, but did not reflect all of the recommendations of the MMSD Report, æBreaking New GroundÆ.This paper considers whether benefits would result from the negotiation of a legally binding and enforceable international protocol encompassing the objectives of the MMSD report or the Toronto Declaration. It attempts to identify the problems associated with implementing and enforcing international mining law, should it be introduced. Aspects of mining operations having cover under customary international law are reviewed, as are rights, obligations and remedies for breaches of national mining law. Conclusions are drawn based on established procedures relating to implementing international agreements. The continuing ability of mining companies to operate within communities will result from each satisfying the communityÆs expectations rather than by complying with largely unenforceable legislation.

Jan 1, 2004

By K Jupp, T J. Howard

Cliffs Natural Resources Pty Ltd (CNR) operates iron ore mines in the Koolyanobbing region of Western Australia, about 50 km north of the town of Southern Cross. Ore is trucked from three geographically isolated sources to the crusher at Koolyanobbing, where it is blended before and during crushing. Lump and fines products are produced and railed to Esperance for ship loading and export to Asian customers. CNR is examining alternative processing paths, from mining to ship loading, with the aim of improving efficiency and reducing costs. Modifications to the system must be consistent with potential future expansions and maintain the low inter-shipment grade variability on which CNR prides itself and has built a strong relationship with its customers. In searching for the optimum process design, many options from mine face to ship loading must be evaluated and compared. Pilot plant studies are infeasible, while complex mineralogical interactions, competing goals and numerous possible system configurations limit the applicability of theoretical analysis. It was therefore concluded that simulation modeling would provide the confidence to take the next step into production trials. This paper describes techniques applied at CNR to simulate grade variability resulting from potential process design changes. The simulation models are easily run Excel-based modules, with each module representing a different part of the process. The modules use extensive Visual Basic macros driven by Excel's user-friendly interfaces. Presentation of the results is enhanced by Excel's excellent graphical capabilities. The simulation software stores and graphically presents time-stamped data from a run, enabling detailed analysis of different process configurations. Final success of a simulation run is measured by inter-shipment variability (standard deviation and process capability) and in-process ore tonnages. Meaningful results from the simulations require the initial input data contain the same correlations present in the real production environment, between the mineral components, production linkages and across time. The data also have to allow simulation of potential changes to mining method and introduction of new pits into the blend. Mining data from the real operations under study are therefore used, with average grades and variability adjusted to match potential future development proposals. It is also necessary to filter out medium and long-term variations from the production data as this variability is best controlled through the conventional medium to long-term mine planning process, not by the process design being studied. The filtering was carried out using a Fourier transform technique, which is described.

Jan 1, 2009

By F Diaz, G Hovestadt, B Friedrich, D Latacz, M Sommerfeld

The metallurgical sector significantly contributes to the global carbon footprint and encounters the challenge of developing more sustainable production methods. This study introduces novel approaches aimed at reducing CO2 emissions within the industrial sector, some of which have been developed up to the demonstration scale. In two case studies, urban waste from the agricultural sector (corn, olives, coconut etc) and waste electrical or electronic equipment (WEEE) recycling residues (shredder light fractions (SLF)) were subjected to thermal treatment. The resulting materials were then used as substitutes for conventional fossil-based reducing agents in both the copper and ferroalloy industries. Furthermore, hydrogen was employed at different scales to assess its efficacy as a reducing agent for recovering metal oxides from fayalitic copper slags. Our findings reveal promising prospects and defined specific challenges for the integration of these alternative reducing agents in the industry. The synergistic use of pyrolysed SLF, bio-coke, and hydrogen presents a viable pathway to significantly diminish CO2 emissions while simultaneously improving the sustainability of the metallurgical sector.

Jun 19, 2024

By S R. Williams

There is a sense of geometallurgy being new; a new methodology for mining project development and improved operational strategy. One of the main challenges that any ænewÆ technology faces is a validation of the value and the need to produce case studies. However, producing case studies can often be problematic particularly given the long cycle from mineral deposit project, through feasibility and construction to stabilised operation of a mine.However, the roots of geometallurgy go back quite some time. Successful practices with geometallurgy can be seen from as early as the 1980s. Many times those practices were not called geometallurgy but something else and, in other cases, what can be seen are various components of the geometallurgical ævalue chainÆ.This paper will analyse a selection of published past practices from a geometallurgical perspective to demonstrate the value realised from the application of this methodology. The paper will then make some general comments on where this history of work in geometallurgy has lead us to and what are the challenges today for the geometallurgical effort.CITATION:S R Williams, 2013. A historical perspective of the application and success of geometallurgical methodologies, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 37-48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By G Gopinath, R Balachander, H S. Venkatesh

This paper describes in detail the controlled blasting adopted and the measurements undertaken for the successful excavation of large twin tunnels under a shallow cover for a six-lane highway project in India. The tunnels are D-shaped, each 15 m in diameter, and the cover between the tunnels and the existing railway track was about 14 m. These twin tunnel tubes were characterised by two separate three-lane carriageways for each direction of traffic, and were planned with about 25 m of reinforced cement concrete (RCC) portals at the entrance and exit of the tunnels. The major challenge of the project was the blasting of tunnels in rock below an operating railway line. As the tunnels approached the area below the railway line, the ground vibrations were monitored vertically above the blasting faces and on the railway track sleepers. Vibration intensities between those generated from tunnel blasting and those from the movement of the trains were compared, and it was found that the vibrations from blasting were lower than those from the moving trains. Though the permissible level of ground vibration based on the Indian Standard (IS) code happens to be 70 mm/s, the maximum charge per delay was calculated restricting this limit to 50 mm/s. This ensured that the vibrations in the vicinity of the railway tracks never exceeded the prescribed limit of 70 mm/s. The surface ground settlement before and after the blasts were also measured using an optical levelling instrument, which confirmed that there was no significant impact on the surface movements due to blasting. Extensometer readings inside the tunnels showed that there was no deformation in the tunnel. These twin tunnels are now operational and are providing faster connectivity with safety.CITATION:Gopinath, G, Venkatesh, H S and Balachander, R, 2015. Controlled blasting for twin tunnels with a shallow cover under an operating railway line, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 801–808 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Recepoglu O, Tolun R, Yavasoglu N, Bulutcu AN

Scheelite was floated from a low-grade (0.28 per cent W03) calcitic (96.30 per cent CaCO3) scheelite ore using oleoyl sarcosine as collector and alkylated 8-hydroxyquinoline as modifier. Compared to oleoyl sarcosine alone, the grade and the recovery of scheelite concentrate were increased from 8.07 per cent to 33.54 per cent and from 55.1 per cent to 73.4 per cent, respectively. Infrared studies with pure calcite and scheelite minerals showed that while alkyl oxine is adsorbed on the scheelite surface, it is not adsorbed on the calcite.

Jan 1, 1993

By C McCamley

"The requisite for maintaining optimal carbon concentration levels in a carbon-in-leach (CIL) circuit is of paramount importance in the prevention of gold losses. The process’s ability to recover gold from the aqueous phase is primarily dependent on the carbon loading profile of the CIL train.Newmont Boddington Gold (NBG) have over 2015 tested the Mintek online carbon concentration wmeter (C2 Meter) suitability for effective carbon concentration measurements in their CIL circuit compared to the standard method where the readings are taken twice a shift by the operations staff. The C2 meter works by passing a 1MHz ultrasonic signal through a slurry containing carbon where there is a relationship between the carbon concentration and the attenuation of that signal.It also highlighted another area where the C2 meter could be implemented at NBG whereby the instrument can be as a cautionary device for carbon losses in place of carbon safety screens.Citation:McCamley, C, 2016. Continuous Carbon Concentration Measurement at Newmont Boddington Gold, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 207–212 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016