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By M Lovitt, T Hewitt

The extraction of drawbells in Lift #2 at Northparkes Mines E26 orebody was achieved by single shot blasting, enabled through the use of electronic detonators. This paper discusses the designs considered at the time of the feasibility study and the various changes made to these designs prior to and during the construction phase of the Lift #2 block cave. Operational issues encountered are highlighted, as are ways in which these were overcome. The amount of personnel utilised to mine the drawbells is also covered. Lists of design and operational considerations to be used for drawbell extractions have been included.

Jan 1, 2005

The Operation of the LAROX PF-50 Pressure Filter at 'Ellatzite-Med' Flotation Plant, Bulgaria The implementation of Larox pressure belt filter, type Larox PF-50 provided within 6˜8% moisture content of the produced copper concentrate, which allowed good market realisation. The start-up of the pressure filter in 2009 reduced the electricity costs several times and had a positive impact on the technological regime of flotation. This article reveals the investigation results from the operation of the pressure filter according to different situations (density of the pulp, time for filtration, pressure of the material, pressure of the drying air, time for drying with air and other factors). The investment made in the pressure filter application is a guarantee for the successful operation of 'Ellatzite' flotation plant, Bulgaria in the coming years.

Sep 13, 2010

By J Hadjigeorgiou

Narrow vein mining, as most types of mining, faces important geotechnical challenges. The specificity of geotechnical challenges in narrow vein mines stems from the nature of the deposits, which are often inclined, discordant and found within fractured rock or faults or in shear zones within country rock. This complicates the construction of representative geomechanical models and limits the applicability of several engineering design tools. Furthermore, in certain cases, the severity of encountered geotechnical problems is considerably greater in narrow vein than in wider orebodies. This paper provides an overview of geotechnical and other challenges in narrow vein mines with a focus on how these are currently addressed. Of particular concern is the use of manual labour working close to the mining face where there is greater exposure to geomechanical hazards. This review concludes with a particular emphasis on understanding the limitations of commonly used engineering tools and techniques to address geotechnical problems in narrow vein mines.CITATION:Hadjigeorgiou, J, 2012. Geotechnical challenges in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

This paper examines the complex interplay of deposit characteristics, mining plans, tailings disposal techniques and rehabilitation requirements on planning for mineral sands operations. All component parts of this mining cycle are interdependent and cannot be evaluated in isolation when optimising a mineral sands operation. This is most evident when projects are large-scale or involve resources that contain complexities such as high slimes content, consolidated hard band materials, acid forming materials and radioactive materials. Projects located in environmentally sensitive areas add further to the need for more stringent planning. This paper describes the analysis techniques adopted by Hatch to evaluate mining and tailings placement options for a dredging and floating concentrator system. The principles and methods used in the analysis are applicable to any mining system involving the complexities listed above. The focus of this paper is on the reconstitution of mined material as tailings and the impact of this process on mining schedules and tailings construction and placement options.

Jan 1, 2001

By R Rimmelin, C Vergara

Heap leach pads are composed of mined ore, usually crushed, disposed on liners to be processed with leach solutions, and the tail of the process is called “spent ore” which are then transported by conveyor belts to be disposed into dumps. It is often to observe stability problems in these dumps, that could affect the equipment working on it and the continuity of the whole mine process. These problems are related to an excess of water content at the spent ore, therefore the operational efforts are focused onto control this geotechnical parameter.This work presents the results of different geotechnical laboratory testing, using samples of spent ore of a mining operation in the north of Chile. In the last 10 years, 3 campaigns have been made to get samples. Valuable information was obtained to identify how specific operational/metallurgical factors could affect the geotechnical behaviour of the spent ore. Special attention is given to the decision to change the metallurgical process adding salt to the heap leach process and its impact to its hydraulic conductivity.Historically, the process has been based on the leaching of oxides and sulphides materials, in separate campaigns, in which it is possible to observe different geotechnical response in the spent ore generated. Recently, it was implemented a new process in which the materials are blended and salt is added, to improve metallurgical performance in terms of recovery. This change generate impacts in the dump, since the geotechnical parameters are affected; decreasing hydraulic conductivity in about one order of magnitude (explained by the salt added).Changes are shown in the geotechnical parameters of the spent ore, considering that the mining source is the same, and how the operational process and dump design are affected.CITATION:Rimmelin, R and Vergara, C, 2018. Geotechnical behaviour of spent ore – impacts of metallurgical factors, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 369–375 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By J C. Koppe, L Vieira

One common problem for blasting in iron ore mines with significant weathering is the occurrence of large blocks of hard rock mixed with softer material. This situation causes a problem for blasting design and sometimes produces large boulders of rock that require a secondary blasting, as well as excavation difficulties. To minimise this situation, geophysical techniques were used to identify the hardest material amid the weathered material. To study the problem, seismic, ground penetrating radar (GPR), electrical resistivity and induced polarisation (IP) methods were used in an intensely weathered Brazilian iron ore deposit. The methods of GPR combined with IP, resistivity and seismic showed to be effective in modelling the contrast among hard, friable materials and soil. The results were used to improve the geological model and create more favourable conditions for the subsequent blast design. The blast design based on geophysical/geological models resulted in significant improvement in the fragmentation of the iron ore. This was achieved by the adoption of a specific drilling pattern for a given geological situation. With the new specialised blasting design the formation of boulders was eliminated.CITATION:Vieira, L and Koppe, J C, 2015. Geophysical techniques applied to blasting design, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 289–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By A Finch, C Pridmore

The Cosmo Project falls within the Archaean to Palaeo-Proterozoic Pine Creek Orogen, one of the major mineral provinces of Australia.The Cosmo Deposit is interpreted to be a series of steep north-west-plunging gold mineralised vein, breccia and shear systems within the tight Howley Anticline and hosted within interbedded siltstones, mudstones, banded iron, phyllites, dolerite sills and greywacke.A folded environment poses a number of technical challenges, particularly for estimation.Handling of tightly folded and in some cases narrow domains might include subdomaining for orientation, omni-directional three-dimensional (3D) estimation within constrained domains or software-enabled unfolding/un-wrinkling procedures (transformation of the data and estimate space into a two-dimensional environment). Each technique has its own unique set of advantages and disadvantages.A further method (one applied at Cosmo) is where the estimation parameters (specifically search and variography orientation) are modified in a frequent or ‘dynamic’ sense to suit the orientation of the domain whilst maintaining 3D space. Control of the resource estimation orientation can be done in several ways, including the use of sectional panels of a specific size or, alternatively, orientation sector divisions. The sector approach provides some significant reductions in processing time over the panel technique and could be applied in a number of software packages.Three-dimensional ‘dynamic’ interpolation reconciles well with production data from Cosmo, whilst the sector method provides a practical technique that can be executed without the complications of transformation or the need for labour-intensive orientation subdomaining and with acceptable resource estimation run time.CITATION:Finch, A and Pridmore, C, 2014. Dynamic interpolation – estimation in a folded environment at the Cosmo Deposit, Northern Territory, Australia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 107–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R Saha, D Barry, C Mawdesley, O Bertoli

Kriged estimates are not typically calculated on blocks substantially smaller than the sample spacing (eg the Standard Mining Unit or SMU). Moreover, the sample spacing for quality variables is often much greater than the SMU size. For short to medium term planning decisions, the shorter term variability in the quality variables is a key economic consideration in defining, setting and meeting coal product specifications.Global uncertainties can be calculated using Drill Hole Spacing Analyses (DHSA). However, knowing the precision of a variable for a one or two year production volume is usually not adequate for variables with low spatial continuity that may fluctuate significantly over daily, weekly, SMU, or shipment volumes.Is there a feasible, reasonable and valid geostatistical method to model the uncertainty of coal quality variables on blocks substantially smaller than the drill spacing (say on the SMU)?The validity of using co-kriging variances, calculated on SMUs to characterise local uncertainty, was tested using a suite of conditional simulations generated for several quality variables for BHP’s Blackwater operation. The conditional simulation results were used as a benchmark against which the results derived from the kriging variances could be compared.The agreement between the kriging and simulation methods for thickness is excellent, with much closer correlations than for the quality variables. Typically, the kriging variances give very reasonable approximations to the simulation-based uncertainties, although there could be some systematic discrepancies which may become much more critical if a classification is to be based on a thresholding of the SMUs relative uncertainties.CITATION:Mawdesley, C, Barry, D, Bertoli, O and Saha, R, 2017. Local uncertainty benchmarking – a coal case study, in Proceedings Tenth International Mining Geology Conference 2017, pp 43–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By L Cain, C Every, S Mirlatifi, J Ashley

This paper presents a geographic information system (GIS) based method for the prediction of ground movement and the associated impact on existing buildings and structures due to tunnelling in the North West Rail Link (NWRL) project. The NWRL is a priority rail infrastructure project for the New South Wales (NSW) Government and includes 15 km of twin tunnels between Bella Vista and Epping, which will be Australia’s longest rail tunnels. The NWRL tunnels will be constructed in an urban environment where the prediction of ground movements induced by tunnelling and the associated impacts to existing structures must be assessed in the early design stages of the project. An assessment process was developed using GIS able to respond to design changes.An iterative GIS analysis methodology was developed to generate ground settlement contours and identify impacted buildings and structures in response to multiple changes in tunnel alignment during design development stages. The GIS analysis undertook to rapidly provide detailed and accurate parameter information including tunnel depth from surface, tunnel separation, diameter and sample point proximity to the tunnel and assess ground movement contours along the project alignment. Determination of the ground surface settlements were based on empirical methods proposed by Peck (1969) and Mair (1993). The control parameters and the relationship between damage categories and risk classifications for impact assessment were based on Burland, Broms and de Mello (1977), Rankin (1988) and Boscardin and Cording (1989) methods.The GIS-based ground movement impact assessment approach adopted for the NWRL project demonstrates an efficient, iterative and robust approach and could provide an initial framework for other similar tunnelling projects where rapid design changes and early understanding of tunnelling impacts are required to bring greatest benefit to all stakeholders.CITATION:Mirlatifi, S, Cain, L, Ashley, J and Every, C, 2014. An iterative geographic information system based approach for the assessment of tunnelling impact to existing buildings and structures, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 647–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By D Connelly

Magnetite orebodies generally means mining lower grade iron ores, crushing and grinding with significant energy costs in processing and the capital costs being significantly higher than for direct shipping ores (DSO). Overseas, the mining and processing of magnetite ores has a long history of production due to the lack of DSO deposits. This raises the question as to why the new magnetite projects have been so problematic and also whether there is a future for the long list of potential magnetite projects in Australia.The quality of the magnetite concentrate product is superior to most DSO products and the magnetite contains energy benefits when converted to hematite in sintering or pelletising. The industry’s hopes for new projects have been dashed and questions are being raised as to the financial viability of such projects.A comparison of Grange Resources Savage River, Arrium’s Project Magnet, the Sino Iron Project and Gindalbie’s Karara Iron Project is used to understand the differences between the projects and why some are more successful than others.CITATION:Connelly, D, 2015. What is the future for magnetite projects in Australia and why have some of the new projects been so problematic?, in Proceedings Iron Ore 2015, pp 107–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By L D. Munro, S A. Jackson

This paper provides a logical approach to developing a TSF design concept through: • Identifying key properties of tailings and containment structures; • Reviewing underlying principles for effective operation; • Showing how these apply to select an appropriate TMS; and • Demonstrating how to align the TMS to site-specific constraints and TSF design. This approach follows a path of rigorous data analysis independent of discharge parameters (whether low-density slurry, paste or cake disposal) to select the most cost-effective and sustainable approach for any given material or site.

Jul 1, 2021

After the last world war, management tended to change from an acquired skill more associated with experience than formal training, to a specific widely-recognised specialism requiring an involved formal education process.That process, of necessity, required the development of business schools, M.B.A. courses -indeed the setting up of professional chairs to deal with the intricacy of general management development.Management research burst forth bringing forward new and exciting theories which developed new techniques, tools and terms.

Jan 1, 1985

By A Woodley, N C. Kunz

A mine site water balance is important for communicating information to interested stakeholders, for reporting on water performance and for anticipating and mitigating water-related risks through water use/demand forecasting. Gaining accuracy over the water balance is therefore crucial for sites to achieve best practice water management and to maintain their social license to operate. For sites that are located in high rainfall environments the water received to storage dams through run-off can represent a large proportion of the overall inputs to site; inaccuracies in these flows can therefore lead to inaccuracies in the overall site water balance.Hydrological models that estimate run-off flows are often incorporated into simulation models used for water use/demand forecasting. The Australian Water Balance Model (AWBM) is one example that has been widely applied in the Australian context. However, the calibration of AWBM in a mining context can be challenging. Through a detailed case study, we outline an approach that was used to calibrate and validate AWBM at a mine site. Commencing with a data set of monitored dam levels, a mass balance approach was used to generate an observed run-off sequence. By incorporating a portion of this observed data set into the calibration routine, we achieved a closer fit between the observed versus simulated data set compared with the base case. We conclude by highlighting opportunities for future research to improve the calibration fit through improving the quality of the input data set. This will ultimately lead to better models for run-off prediction and thereby improve the accuracy of mine site water balances.CITATION:Kunz, N C and Woodley, A, 2013. Improving the accuracy of mine site water balances through improved estimation of run-off volumes, in Proceedings Water in Mining 2013 , pp 267-272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By P Micale

Geological data provides the foundations for the mining value chain. It is used to underpin the modelling and planning and consequently optimise downstream business decisions. However, it is often forgotten or taken for granted. End users often assume the data to be sound without verification. Geological data can be considered a company’s number one asset. Subsequently, the storage, use and management of this data need careful curation and time invested in preserving and protecting it. An established polymetallic mine with 20 000 drill holes could have a data replacement value in excess of $500M at 2020 prices, excluding labour and salary costs. The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (the ‘JORC Code’) provides guidelines for Public Reporting. Within the code, Table 1 requires discussion around the different types of geological data, its collection and use. What is needed is additional details regarding the validation and integrity of the geological database. A comprehensive guideline specifying minimum geological standards for geological databases has been developed. This expands on the critical points outlined in Table 1 of the JORC Code. This guideline can be used by companies where geological databases are managed in-house or used to assess these services’ outsourcing. This guideline will ensure that geological data is reliable and unadulterated and can be used with confidence. Using this guideline will assist in preserving the investment of geological data in the mining value chain

Mar 22, 2022

By A Muhairini, M Eggers, J Smith, H Baxter

Detailed geochemical analysis of cored and non-cored drill hole data was used to characterise and model the Cenozoic detrital valleys of several deposits within the southern Pilbara region, Western Australia. The purpose of this modelling was to better characterise and understand the relationships between the various geotechnical units comprising mixtures of rock and soil for the purposes of slope stability and depressurisation studies.This paper presents data from several valleys where geological, geomorphological and climatic processes have resulted in the deposition of heterogeneous detrital rock and soil sequences. Seven primary detrital units are recognised as occurring within all the valleys studied, suggesting that the geological processes involved in the erosion and deposition of the units were widespread. Geochemical assessment of cored and non-cored data suggests correlatable geochemical signatures can be recognised for each of the units; however, local variability in the groundwater history of individual valleys is demonstrated by late-stage carbonate precipitation recognised both in the core and through the geochemical signatures, which has resulted in alteration of the parent rock/soil material. This paper discusses how the carbonate alteration may lead to improvements in rock/soil mass strength of a clay unit by comparing laboratory strength test samples of the same parent material with varying degrees of precipitate alteration to those with no discernible carbonate alteration. Following from this, correlations with geochemical assay results have been derived, whereby zones of more favourable strength conditions may be modelled through assessing areas of analogous geochemistry.The paper demonstrates how geochemical assessment can lead to improved geotechnical and hydrological modelling for a detrital valley system without the need for significant coring and laboratory testing. This in turn leads to improved confidence in the slope design and depressurisation recommendations for a slope.CITATION:Baxter, H, Eggers, M, Muhairini, A and Smith, J, 2015. The effect of carbonate alteration on detrital mass strength and implications for geotechnical slope design, in Proceedings Iron Ore 2015, pp 429–436 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By T Sprague, D Pateman

"The Gosowong Gold Project is owned and operated by PT Nusa Halmahera Minerals (PT NHM), an Indonesian company 75 per cent owned by Newcrest. It is located on Halmahera Island, in the North Maluku Province of the Republic of Indonesia, approximately 2450 km north-east of the national capital, Jakarta (Newcrest, 2017).Kencana is one of two underground gold and silver mines at the Gosowong Operation where ground conditions vary from competent to very poor. Development headings occurring in poor rock mass conditions require high capacity ground support including long tendon cable bolts. Manual installation of cable bolts in these development headings has been a time consuming process due to borehole collapse, blockages requiring subsequent re-drilling and a minimum eight hour grout curing time interval. The installation of cable bolts including the setting, plating and tensioning can impact the critical path for development heading advance resulting in development cycle delays.A review was conducted by PT NHM on current industry practices for alternatives to manual cable bolting. PT NHM subsequently approached Minova to assist with the development and trialling of self drilling anchors (SDAs) installed using jumbos with a rapid setting pumpable resin, CARBOTHIXTM. A series of system development trials were conducted and a reliable bolting system was developed utilising the existing jumbo drilling fleet with minimal required modifications.The system developed was a ‘one pass’ bolting process to install and grout SDAs using a two component resin with a remote, mechanised system. Improvements achieved from the system include: eliminating hole closure issues and more immediate support in poor rock mass effectively reducing personnel exposure to poor ground conditions by removing the requirement to access the drive backs reducing grout set time with full installation times for 6 m SDAs averaging 25 min.The resin grouting system has now been successfully implemented to effectively manage areas of poor ground conditions and to accelerate advance rates in high priority headings.CITATION:Pateman, D and Sprague, T, 2017. Development and implementation of a long tendon bolting system utilising resin grouting technology, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 79–84 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

By J Rutter, D Francois-Bongarcon, M Federov, N Odiar, M Scott

There are two fundamental methods for metalliferous sensing of primary crushed ore available for deployment at operations. These methods can be classed as surface measurement techniques (including XRF, LIBS, NIR, SWIR) or penetrative/semi-penetrative measurement techniques (including PGNAA, PFTNA, GAA, MR). While the individual sensing technologies exploit different physical phenomena to measure metal content, penetrative sensor measurements of grade are often regarded to be superior to surface measurement techniques due to the much larger sampling volume penetrative techniques provide. Surface sensing techniques often utilise simpler, established technologies that have considerable benefits in the speed of analysis, capital costs, ease of deployment, social license to operate and operational safety. This paper investigates whether surface sensing techniques achieve adequate sampling representativity of primary crushed rock mass to provide economic benefit over penetrative sensing technologies for bulk ore sorting applications. The paper details the methodology used to assess whether surface XRF measurements change throughout various stages of comminution, and increased surface exposure, from primary crushed ore (top size of -175mm) to finely crushed product for assay (top size -2mm). The methodology was applied to 2 ore mineralisation styles, across variable metals and grades, to identify any associated opportunities and limitations to surface sensing techniques. The results assist in developing a method to determine if surface sensing and measuring via XRF is an adequate representation of the rock mass for bulk ore sorting applications and identify any associated limitations in particle size distribution, mineralisation or natural deportment strength to guide suitable application of surface sensing techniques.

Nov 10, 2020

By D McCoy

Titanium feedstocks are the building blocks of the titanium value chain. They can be mined directly, as is the case for ilmenite, leucoxene and rutile, or manufactured from ilmenite by extracting various quantities of non-TiO2 components from the ore by chemical and/or thermal processes.While feedstocks can be grouped into categories of materials with similar characteristics, they are essentially unique products from very different mining locations around the world. In fact, no two feedstocks are exactly the same. As such, the variations between the available feedstocks, in combination with the permutations in processing technologies to turn the feedstocks into titanium pigment or metal, mean that choices between feedstocks are specific to the location in which they are utilised.In this paper, the authors examine the key requirements of titanium feedstocks to the TiO2 pigment and metal sectors. Apart from the well known differences between feedstock choices for the sulfate and chloride process, the more opaque considerations in feedstock sourcing are examined.

Oct 5, 2011

By H Wang, D Wang

Mine dust is the most serious occupation hazard in coalmines. And many coal workers suffer from pneumoconiosis because of long-term inhalation of respirable dust. Reducing the dust concentration of workplaces by effective technical means is an important way to prevent coal worker’s pneumoconiosis (CWP). In order to overcome deficiencies in existing dust control technology for underground mining, especially the disadvantage of water spray technology mounted on roadheaders or continuous miners, the authors developed an integrated dust suppression technology utilising foam for fully mechanised heading faces. This paper presents an overview of the principles, materials, equipment and application of this technology. Among these, a jet type foaming device and a green foaming agent were developed, which can realise the goal of efficient preparation of foam. In addition, an arc fan nozzle used for foam spraying was invented, which can effectively cover and enwrap the dust produced by the roadheader at the cutting point and achieve the goal of efficient utilisation of foam. This dust suppression application of the proposed foam technology was investigated on fully mechanised heading faces. The results show that the dust concentration was cut down significantly with a dust suppression efficiency of greater than 85 per cent, an increase of over 30 percentage points compared to the water spray system. This study demonstrates that this foam technology can play an important role in dust suppression on fully mechanised heading faces, which provides an important method to improve the working environment and protect coal workers’ health.CITATION:Wang, D and Wang, H, 2015. Technology of dust suppression by foam for fully mechanised heading face, in Proceedings The Australian Mine Ventilation Conference, pp 177–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By B Young

Variable bench heights, interaction with underground workings and a steeply dipping orebody are challenges faced daily by geologists at Xstrata Zinc’s Black Star Open Cut (BSOC) Zinc/Lead/Silver mine in Mount Isa, Queensland.BSOC has been in operation since late 2004 and was developed to extract the surface extents of the Zn/Pb/Ag mineralisation mined in the underground lead mine. To date many large scale stopes and extensive development drives have been intersected and successfully mined. The stratigraphically hosted orebodies strike in a north-north westerly direction, dipping ~75° west. Ore production from the pit is currently at 4.5 Mt/a.Historically, sampling was conducted using a multiple spear technique from blasthole cuttings. This method proved to be relatively reliable when blasting benches at a consistent height, but a requirement to vary bench heights to safely collapse and then mine through underground workings reduced sample representivity to unacceptable levels.The purchase and commissioning of a production rig which had been converted for reverse circulation (RC) has allowed for the flexibility of a small rig, with the capacity to easily drill 48 m holes while ensuring sample quality. Sample quality is not the only benefit of introducing RC grade control. By collecting grade control data well in advance, informed decisions can be made by planning, drill and blast and mining departments weeks beforehand, rather than hours before firing. Additionally, seeking operational value to offset higher drilling costs has proved positive with benefits including increased confidence in orebody wireframes, accurate tonnage and grade for proceeding five benches along with the ability to representatively test metallurgical response on a tight grid spacing.

Aug 22, 2011