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The borehole televiewer is a downhole geophysical logging device that produces continuous, oriented, 360¦ images of the drill hole wall. Two types of borehole images are currently being generated at the BHP Billiton Mount Whaleback deposit. The optical televiewer (OTV) tool captures a ærealÆ image of the borehole wall whereas an acoustic televiewer (ATV) generates an image through variations in physical borehole size, scattering the energy from an acoustic beam. Orientation of the resulting ævirtual coreÆ is derived through magnetometers and accelerometers, providing values within one degree for both inclination and azimuth. Downhole structures such as fractures, joints, foliations and bedding planes are selected directly off the borehole image, recorded and displayed in a 3D modelling package along side adjacent drill holes. Measurements are corrected from apparent to true dip and magnetic to true north. Strata-bound magnetic anomalies are identified and corresponding measurements excluded. The importance of borehole imaging increases substantially with its ability to integrate the OTV and/or ATV data with other forms of lithological and structural data. At Mount Whaleback, the borehole televiewer has been implemented to provide information for geotechnical exploration including structural analysis, lithological characterisation and rock-mass conditions. Within the large area in and around Mount Whaleback, drilling may intersect a number of different geological formations with various rock types and conditions. With the application of the borehole televiewer, reverse circulation drilling can provide information traditionally obtained by diamond drilling.

Jan 1, 2007

By Stille H

The choice between drill and blast and mechanical boring methods is often not obvious. There are several factors which may have a de- cisive influence on this choice, such as the geometry and length of the tunnel, site con- ditions and borability of the rock. Both the un- confined compression strength and the joint dis- tance have a considerable influence on the net penetration rate. Site conditions, rock quality and water conditions influence the utilization of the tunnel boring machine. The drill and blast method is normally less sensitive to devi- ations from assumed ground conditions.

Jan 1, 1987

By S A. Ravishankar, W Perez

Flotation is one of the main concentration processes to purify kaolin clay via the removal of naturally occurring impurity minerals containing Ti and Fe. Currently, there are two types of collector chemistries used in the industry to float coloured impurity minerals. These are traditional tall oil fatty acids (TOFA) and specialty hydroxamate (AHX) based collectors. AHX based collectors have long been known to be the most selective collectors to float Ti and Fe based coloured impurity minerals (CIMs) as compared to TOFA based systems. AHX based collectors provide, not only improved selectivity and simplified process, but also more importantly, make it possible to treat certain kaolin resources that do not respond to standard TOFA systems. However, the relatively higher cost of straight AHX collectors has restricted broader application of these collectors in kaolin clay and other oxide flotation applications for a long time. Recent technological advancements, in both making and formulating AHX products more economically, increased the usage of these collectors in kaolin applications. Modified AHX products offer more economical alternatives and process options to provide high purity kaolin clay products for specialty applications based on cost-performance criteria. In this paper, the flotation performance of a series of newly developed AHX formulations is provided along with the characteristics of AHX flotation in general. In addition, flotation performance of earlier AHX collectors is provided based on published literature as background data.

Jan 1, 2005

Most internationally traded iron ore resources are derived from multiple mine sites, transported to a port facility where they are blended and possibly further processed prior to shipping. Provided the proportion of contributions varies over a number of shipments an estimate can be made of the bias introduced by mine site sampling, analysis and materials handling systems, using zero-intercept multiple linear regression. Further regression applied to the residuals allows the error variances for the source mines to be estimated. Various sampling strategies are used by the industry. All have shipment-loading sampling on which payment or at least provisional payment is based. In most cases sampling prestockpile is used at mine sites to verify estimated production grades. Train grades are estimated from mine stockpile grades and in some cases train grades are verified by port input sampling. The methodology used is presented in this paper. Simulated data have been used and do not reflect the actual performance of any operator. The merits of the various systems and the implementation and potential limitations of our method are discussed more fully in a companion paper (Ziegelaar and Everett, 2010).

Mar 1, 2010

By R F. Sandenbergh

Due to environmental considerations, mineral processing plants are increasingly recycling water to decrease the impacts of wastewater on environment and the depletion of fresh water resources. Industrial experience has shown that increasing recycling water in flotation typically negatively impacts the recovery and selectivity, especially in the selective flotation of minerals from complex sulfide ores. The major reason for the reduced selectivity is typically the inadvertent activation of sphalerite or pyrite by the heavy metal ions (HMI) in solution. These HMI are often produced during milling and flotation and absorbed by other minerals. In the normal flotation pH value range (8 - 10), these HMI are often in the form of precipitates or complex ions that may re-appear in solution or become active should conditions favour this. In this paper, microflotation, batch flotation and XPS surface measurement were used to investigate the use of HMI absorbents additions to the pulp to improve flotation selectivity of a complex sulfide ore. It has been demonstrated that HMI removal does improve flotation selectivity by facilitating more effective depression of the sphalerite. Microflotation and XPS surface measurements have shown that HMI absorbents compete with sphalerite to absorb HMI, and thus reduce the surface concentration of HMI on those sulfides. The practical use of HMI absorbents in complex sulfide ore flotation is also discussed.

Jan 1, 2005

By P Murthy, Z Guan, P Townson

In this paper, we introduce a methodology to optimise mining equipment operation in terms of the conflicting concerns of productivity and availability. We also introduce the concept of damage points and equipment dutymeters. These provide the mine management with tools to monitor the success of such optimisation. Since we have quoted the results of an on-going Australian Coal Association Research Program (ACARP) project, the apparent focus of this article is on draglines. However, the concept is equally applicable to other equipment. Mining is the type of business that requires a large investment in capital infrastructure and equipment to produce a product that is sold at a relatively low unit cost. In such a business, the key to competitiveness lies in achieving the full realisation of capital investment ie sustained production at high levels. Some of the concepts outlined in this paper are essential components of this picture.

Jan 1, 2000

By J Col, D La Rosa, W Valery, A Jankovic

Metso Minerals Process Technology Asia-Pacific and South America (MMPT) has been working with operations around the world to increase their efficiency through æMine-to-MillÆ or Process Integration and Optimisation (PIO) projects. These projects have delivered significant improvements in mine efficiency, mill throughput and reduced operating costs at mines around the world. The MMPT methodology involves rock characterisation, site auditing, data collection, modelling/simulation and implementation of integrated operating and control strategies on site. This results in significant benefits to the operations û for example, 5 to 20 per cent increases in concentrator throughput have been measured. MMPTÆs rock characterisation utilises simple and inexpensive measurements that can be performed by trained site personnel. The advantage of these measurements is that a large amount of data can be collected in a very short timeframe, as the samples do not require shipping to an outside laboratory. Typically, a PIO project starts with a site visit to perform blasting and process audits, collect high quality data including measurements of run-of-mine fragmentation and survey data around all crushing and grinding circuits. These measurements are combined with rock characterisation and the definition of strength and structure domains to model the complete production chain. Site-specific models of the blast fragmentation, crushing, grinding and flotation processes can then be developed. This proven methodology has applications ranging from greenfield projects to long-standing operations with AG/SAG or conventional grinding circuits. Process improvements can be higher mining productivity, higher mill throughput, decreased overall operating costs and higher flotation or leach recovery. This paper discusses a recent application of PIO conducted at a large open pit operation in South America and emphasises the potential that every operation has to ædo more with what they haveÆ.

Jan 1, 2007

By T Baard, A Pieters

This paper deals with the design and implementation of a 17 MW (nominal) surface cooling installation at Impala Platinum No 14 shaft located in Rustenburg, North West Province, South Africa.The cooling requirements included the installation of a surface ammonia refrigeration plant complete with the storage of hot and cold mine service water for underground use. It was also necessary to install a surface bulk air-cooling facility, which cools 400 kg/s of ventilation air going to the underground workings. Primary cooling is to the surface bulk air cooler. The cooling duty of a surface bulk air cooler is heavily dependent on the ambient wet-bulb temperature. Because of the daily wet-bulb temperature variation in this part of the world, use was made of a cold thermal storage facility of four million litres. The excess chilled water is stored during the night, for use by the main drilling shift during the day. This keeps the refrigeration machines as close as possible to full load during the summer, thus maximising the use of the capital expenditure. This paper discusses the control philosophy used to maximise the cooling output, as well as the thermal process. The project consisted of two phases resulting from the underground development phases of the mine. The first phase started in January 1999 and was commissioned by the end of the same year in record time. The final commissioning of the second phase took place at the end of 2002. The most difficult part of the construction phase was the tunnelling of a subsurface air duct from the bulk air cooler to the operating vertical shaft. This was done without disruption to the hoisting of men, material and ore in the shaft. Owing to the size of the refrigeration machines, the ammonia quantities involved and the application on a mine (no ammonia can go underground, either in the service water or in the mine air) special precautions had to be taken. South Africa has developed high standards for ammonia refrigeration plants used on mines, which will be partially dealt with in this paper.

Jan 1, 2005

By J E. Powalisz

"The application of automated sampling techniques can help to provide a representative sample of process fluids and slurries that provide data for controlling process, custody transfer and quality assurance and quality control purposes.The automation of sampling provides a more consistent and reliable sampling process and eliminates many of the human-induced errors. Automated sampling can also provide a higher degree of safety in the plant/processing environment as well as better bottom-line results.Automated, fixed volume samplers can provide a very representative sample by integrating many small ‘grabs’ of sample from a process. Automated samplers can be controlled in a variety of ways to optimise the sampling process, including:cycle ratedwell timetotal volume.Properly selected and applied, an automated sampler can effectively isolate the operator from the process fluid during sampling and, to a great degree, during sample container collection.A variety of materials of construction, including seals, are available to handle demanding mining applications. Alloy 625, alloy 2205, AL6XN® and even certain plastics are used successfully in mining slurry applications.This paper explores the application of automated, fixed volume, batch style samplers in copper/nickel and gold processing, specifically pregnant leach solution and extraction fluids.Several specific field applications are discussed, including process installation details, hardware and operation.CITATION:Powalisz, J E, 2014. The application of automated samplers in copper/nickel processing, in Proceedings Sampling 2014, pp 35–42 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 29, 2014

 Increasing concern about the impact of alluvial mining discharges on the water quality of some West Coast rivers lead to a joint West Coast Gold Miners Associate, Trade and Industry funded study by Water Technology (NZ) Ltd. The objective of the study was to assess the treatability of West Coast alluvial gold mining discharges and to develop simple treatment systems which could be effectively adapted to a variety of sites in the region.   The approach was to apply standard water treatment techniques to field situations using low cost technology. Initially the various types of alluvial gold mining operations were identified then after preliminary site investigations and laboratory studies were carried out, site pilot plants were set up. The results of the trials particularly those using chemical aids were encouraging and it was found that chemical aid performance was largely dependent on the degree of mixing at and downstream of the chemical addition point. Design alterations to settling pond configurations in conjunction with optimised chemical addition yielded dramatic results in the form of reduced effluent turbidities.   A generalised approach to effluent treatment was developed and some of the specific 'mix and match' requirements were identified for different types of sites. The general conclusion is that improved physical treatment combined with good plant management and operation and (where necessary) chemical treatment, will produce water of acceptable discharge quality.

Jan 1, 1989

The N3500 orebody is the northern continuation of the 3500 orebody at Xstrata Copper's Enterprise Mine and occurs at a depth of 1.3 to 1.8 km. At the nearby S3500 orebody, extreme deformation was observed in access drives where there was a high number of bedding planes per metre combined with either graphite or talc infill. The observed failure mechanism was largely controlled by the geometry of the inclined bedding submitted to high horizontal stresses. Due to the anisotropic strength and deformation behaviour of the shale rock mass, traditional isotropic methods of geomechanical property estimation based upon GSI are not appropriate. A numerical modelling approach, based upon the distinct element codes UDEC (2D) and 3DEC (3D), has been developed to accurately simulate the failure mechanisms and deformation observed in the initial infrastructure surrounding the N3500 orebody.

Nov 25, 2010

By T Raynlyn, S Hapugoda, V Nunna

The predominant phase in most Marra Mamba, channel iron deposits and detrital iron ore deposits is goethite. Goethite abundant iron ore fines tend to have complex mineralogical associations and fine dissemination of gangue material. These ores are typically challenging to process using conventional beneficiation methods. With declining ore grades, there is a need to develop new processing routes for low-grade goethitic ores/fines.Comparative process amenability studies were carried out using two different processing options to recover iron with low alumina and silica content from a low-grade goethite-abundant iron ore fines (-2 mm) sample from the Pilbara region of Western Australia. The first option involved dehydroxylation at 350°C and 400°C, followed by grinding dehydroxylated samples to 100 per cent passing 106 µm and magnetic separation. The second option was processing raw sample by gravity separation using a Floatex density separator. The performances of the two processes are discussed in terms of the iron grade-recovery responses, and an optimal processing route is proposed based on the findings from these tests.CITATION:Nunna, V, Hapugoda, S and Raynlyn, T, 2015. Process amenability studies on goethite-abundant iron ore fines, in Proceedings Iron Ore 2015, pp 165–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By S J. Henderson

Pumped co-disposal of coal processing waste was promoted in the 1990-2000s as a low-cost highperformance alternative to tailings dams. In particular it would avoid high up-front capital for rejects trucks and dam embankments, and would produce a combined waste deposit with better geotechnical properties than either coarse rejects or tailings. Overall, the promise was not delivered; in particular, upon discharge the waste segregated by size, and operators responded by moving the coarser waste to contain the finer waste. In consequence, not only did design analysis lag behind construction, but some of the initial expectations persisted with the result that analyses did not fully represent what was occurring on the ground. After more than twenty years inspecting, designing and tending Co-Disposal Areas (CDAs), it is apparent that they are essentially upstream constructed tailings dams with some more favourable aspects but also a few unique quirks. Although waste management technology has moved on somewhat, the high cost of changing CHPP waste circuits means that most mines with pumped codisposal will continue to discharge mixed waste slurry into CDAs. It is therefore worthwhile to share some lessons in the hope of promoting sounder design, operation and rehabilitation. These include: • Discharged waste does not form a homogeneous wholly competent deposit but instead comprises materials ranging from sandy gravel to silty clay with the distribution determined by movement of the discharge and decant structures; • CDAs circulate and contain a lot of water; • As a result of the first two points, some areas of the CDA comprise saturated fine waste that is no different from tailings and, like tailings, often behaves in an undrained manner; • Seepage is inevitable and desirable because strength improves as water is removed. However, stability is strongly impacted by pore pressures and in design these need to be rationally rather than optimistically considered; • As CDAs are built to about 40m or higher, strength-deformation characteristics of the foundation become more important; • Even if geomechanically stable, CDAs will need covers to prevent salts and acids from reaching the surface; and • Erosional stability of the cover material(s) will probably dictate maximum slopes for rehabilitation.

Jul 1, 2021

By E P. O’Dwyer

Segment and gasket lining in tunnel boring machine (TBM) tunnels; and sheet membrane lining systems in driven tunnels are robust waterproofing systems each with a proven history of performance in Australia and further afield. Where an interface between these two systems occurs, the potential for costly failures is vastly increased and additional attention to detail is required in design, planning and construction. TBM cross-passages represent the most common occurrence of this interface, with steel compression flanges and neoprene gaskets being the typical means of connecting the waterproofing systems. There is a large variance in both detailing these flanges and associated outcomes, which makes this an area where there is room for improvement within the industry.The paper will look to tease out the various issues associated with this interface and how they can be dealt with efficiently with appropriate design measures, robust planning and carefully controlled construction methods.The paper will also look to review the new technologies and systems currently being put forward as potential alternatives, including an epoxy tape system, which has recently been successfully trialled on a project in Europe under high-pressure head.CITATION:O’Dwyer, E P, 2014. The challenge of waterproofing cross passages in segmentally lined tunnel boring machine tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Ferreira

To speed up multivariate geostatistical simulation it is common to transform the set of attributes into spatially uncorrelated factors that can be simulated independently. One decorrelation method is the method of minimum/maximum autocorrelation factors (MAF), where a two structure linear model of coregionalisation is assumed. The transformation decorrelates the theoretical model exactly, but the actual data are only approximately decorrelated. The MAF transformation can therefore be seen as a special case of a non-orthogonal approximate diagonaliser of a set of symmetric matrices. A more general approach for approximate joint diagonalisation (AJD) has been developed in the context of blind source separation. For these AJD algorithms no assumptions are made beyond symmetry of the individual matrices and so they can be applied to a family of experimental semivariogram matrices. In their application there are no restrictions on the number of structures in the linear model of coregionalisation (LMC) thus removing one of the conditions placed on the subsequent modelling of the spatial structure of the factors. In this paper the general background for the U-WEDGE AJD method is presented. It is shown that the U-WEDGE method achieves better spatial decorrelation than the MAF method. The factors derived from U-WEDGE are simulated using conditional turning bands simulation and then backtransformed to attribute space.

Sep 26, 2011

By K Saito, M Hasegawa

In steelmaking processes, it is known that P2O5 in dephosphorisation slags often exists in solid solutions between Ca2SiO4 and Ca3P2O8, <C2S-C3P>SS, and thus the solid solutions play an important role in the dephosphorisation reaction. Hence, the knowledge of thermochemical properties, ie phase relations and activities of components, in slags containing <C2S-C3P>SS are necessary for the effective removal of phosphorus from hot metal. In this study, the P2O5 activities in <C2S-C3P>SS were measured through the gas equilibrium method. In the present experiment, oxide samples were equilibrated with Cu-P liquid alloys at 1573 K under a stream of Ar + H2 + H2O or Ar + H2 + CO2 gas mixture in which oxygen potential was fixed and then equilibrium phosphorus concentrations in the Cu-P alloys, [mass%P]Cu, were analysed with ICP-OES.

Aug 21, 2024

By R J. Thompson

In truck-based hauling systems, the mine haul road network is a critical and vital component of the production process. As such, underperformance of a haul road will impact immediately on mine productivity and costs. Operations safety, productivity and equipment longevity are all dependent on well-designed, constructed and maintained haul roads. With the advent of autonomous haul trucks, the haul road itself becomes all the more critical to the success of these type of operations; not only in relation to mine operators requirements for safer and more efficient and predictable haulage systems, but also in response to autonomous truck manufacturers’ requirements for a more predictable and controlled operating environment. This paper presents a brief summary of the state-of-the-art in surface mine road design and then proceeds to examine the design and technological challenges associated providing a safe, predictable and affordable road for autonomous mine haul trucks. The paper serves as a basis for evaluating the contributions that enhancements in road design and management can deliver to autonomous mining operations, an initiative that also has scope for adoption within the operating life of many mines, haul roads and haul trucks.

Nov 22, 2011

By A M. Ebbels

"Underground mine scheduling decision-making has been based on production requirements, equipment productivities and the mine planner’s instincts on the best scheduling strategy for the mine to optimise the net present value (NPV) of a project.In the last few years, innovative software has been developed to optimise underground schedules based on NPV. The schedule optimisation tool (SOT) allows the user to set up scenarios based on grade, metal content, capital and operating costs.This paper discusses the results of two case studies undertaken using the SOT software to optimise the NPV of the projects.In each case study, the SOT software has been applied in two ways:using the original mine planner’s scenario and determining whether the NPV could be improved by changing resource capacitieschanging the scheduling goals to determine whether a different mining strategy would have a better NPV outcome.The outcomes of the case studies demonstrate that the mine layout and design were contributing factors to the overall improvement of the NPV and that SOT has a more noticeable impact on the NPV of projects where less sequence constraints are required, such as geotechnical sequencing and access development.CITATION:Ebbels, A M, 2016. Optimising underground mining strategies, in Proceedings Project Evaluation 2016, pp 60–65 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By A Tsoy

This abstract describes long-term mining schedule optimisation approach that may be suitable for complex marginal projects and is based on modern scheduling techniques. CITATION: Tsoy, A, 2018. Strategic mine schedule optimisation, in Proceedings Complex Orebodies Conference 2018, pp 91–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Nixon J

Open pit mining began in 1978 at the Woodlawn base metals deposit. For its ten years as an open pit the mine was financially unsuccessful as a combined result of difficult metallurgy and industrial unrest. In 1985 CRA bought out two American joint venturers with a view to going underground and a prerequisite to expending capital on developing an underground operation was to improve the industrial climate, work practices and mining methods.Following feasibility work, continuous production from the underground mine began in 1986 using mechanised cut and fill methods and a workforce trained under a multiskilling program. Men with no previous underground experience were trained by supervisors with backgrounds as miners to undertake all the work that is required with increases in skill levels being rewarded with increases in pay.

Jan 1, 1992