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By B King

A large number of mineral deposits contain regions in which it is economically beneficial to extract ore both via open pit and underground mining techniques. Current industry practice lacks an effective means to establish the extent of the open pit and underground mining areas for an individual deposit. We present a mixed integer programming model for scheduling both the open pit and underground mine that can be used to create a holistic extraction sequence for a specific deposit. The model considers both spatial and temporal elements of the open pit and underground mines in order to maximise the net present value of the entire deposit, while adhering to its production, processing and block sequencing constraints. By doing so, we can schedule the open pit and underground in concert.CITATION:King, B, 2014. Modelling open pit and underground production scheduling in concert, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 369–374 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By H Fletcher

Iron Ore Holdings Ltd (IOH) is an emerging junior iron ore company that is actively developing projects in the Central and Western Pilbara region of Western Australia. IOH commissioned URS Australia Pty Ltd (URS) in mid-2008 to prepare environmental assessment documents for the Phil’s Creek Project, which was rapidly moving into the development phase. This project comprised a small open cut iron ore mine that was expected to deliver approximately seven million tonnes over a five year mine life.IOH faced several challenges in the environmental assessment process for the Phil’s Creek Project. Although the Phil’s Creek Project attained approval but has now been placed on hold, it is a useful case study to discuss these challenges and how IOH addressed them. Several important lessons were learned through this process that can assist other proponents in addressing environmental challenges in a constructive and proactive manner.One major challenge faced by IOH related to the endangered northern quoll (Dasyurus hallucatus). Another challenge was the unusually high species richness of troglofauna recorded within the project area, with several species initially known only from within the proposed pit footprint.Meeting and overcoming these challenges has provided IOH with an increased understanding of the level of input required for consultation with government departments regarding environmental assessments, and this should stand the company in good stead for developing future tenements. Challenges in regards to the environmental assessment process may be faced during future developments, but IOH’s experiences to date and the lessons learned from the Phil’s Creek Project, will help pave the way for successfully overcoming them.

Jul 11, 2011

By V Gau, L Overmeyer, M Kesting

Economically efficient mining processes can be significantly assisted by the implementation of sensor technologies for the detection of materials and boundary layers between materials inside the stratum. These sensors are meant to facilitate the machinery operator and illustrate furthermore the prerequisites in assisting tools towards fully automated mining equipment. Therefore, project æSensory Identification of Material Type and Detection of the InterfacesÆ (SIMT) aims at the integration of ground penetrating radar (GPR) and geoelectric sensor technology by endowing with them a bucket of a bucket wheel excavator. For this reason, a sensor bucket was developed and tested in the Inden Mine of RWE Power AG. The feasibility of integration and deployment of such sensor technology has been proven effective for the conditions of open cast mining. The main focus of current research lies on developing algorithms to analyse the acquired measurement data from the sensors to automatically detect layers and materials. A computer network receives the GPR and geoelectric measurement data as well as the positioning data of the sensor bucket. The positioning data mainly consists of GPS and encoder information, which is merged with the sensor data by using the UTC time stamp. With the aid of consecutive processes the relevant information will be extracted and provided to the user. The aim of SIMT is to replace material identification, traditionally carried out by the operator, by implementing a continuous operating interpretation system in mining equipment based on GPR and geoelectric sensor technology, resulting in more detailed information regarding the working face during an excavation. This detailed information provides an opportunity for efficient planning and controlling of selective mining of natural deposits, such as the process of lignite mining.

Sep 26, 2011

The results of the washing of coal are often presented by using Partition Curves. By analogy, it is possible to express the results of screening by using similar partition curves. As in the coal washing processes, this method determines the accuracy of screening and is also suitable for different separations depending on the difference in size distribu- tion. This method compares the effectiveness of two screening operations and forecasts the performances.

Jan 1, 1984

Strip mining offers the advantages of high productivity from both human and capital resources as well as high rates of production. Experience suggests that it will be advantageous to extend strip mining to the maximum pos- sible depth in order to minimize costs and maximize the recovery of the in situ coal reserves. Highwall and spoilheap stability pose significant problems. Deep working in strip mines is likely to produce a change from methods which are based upon the elevation of material followed by dumping, to methods involving elevation and horizontal transport. There is considerable scope for optimizing the types of machines and minimizing the amount of double handling.

Jan 1, 1975

The use of scrapers in mining and earthmoving operations is not new; in fact they are one of the earliest methods of bulk earthmoving. A single machine, which can load, haul, and dump material with a minimum of ancillary support is a highly productive and cost-efficient method of earthmoving. In recent times scrapers have been unpopular due to perceived problems and operational limitations, but the last couple of years have seen a resurgence in the use of scrapers in the Bowen Basin as a primary prestripping tool. The main operational limitation of scrapers is the economic operating range. Maximum productivity and lowest cost per bcm is achieved on short leads, as the lead distance increases the cost per bcm quickly reaches and then overtakes that of an truck-excavator fleet. The geometry of a ætraditionalÆ coal mine does not readily allow short leads for prestrip fleets due to the nature of dragline stripping operations. The strip arrangement means that material has to be taken around the end of the pit, meaning a longer haul distance than the actual point-to-point distance between load and dump. This can be alleviated by using pit bridges, however these can cause spoil problems for draglines if not properly planned and have been avoided by many mines. Due to the economic haul distance limitation of scrapers, truck-excavator fleets have become the normal method utilised. Currently more geologically complex mines are opening up, which do not allow traditional down-dip strip mining to occur. Cross-dip mining methods allow for short leads between prestrip loading and dumping areas, hence scrapers and bulk doze are realistic alternatives to a truck-excavator fleet in the prestrip environment. Keeping the lead distance to a minimum a fleet of 657Æs can move material at a very low cost. The other main operational limitation of scrapers is the type of material that can be economically excavated. Hard material can lead to damage to the bowl, free-flowing sand will not readily stay in the bowl leading to reduced load factors. Ripping the material with a dozer prior to excavating can lead to improved loading time, and greatly reduced GET consumption. When considering scrapers for prestrip operations a number of things must be considered: is the lead distance within the economic haul distance? should twin power (push-pull) or single power (dozer pushed) scrapers be used? do I need to rip, what should I rip with? what ancillary support is required? is there another system already available on-site which is currently under utilised? This paper considers the parameters under which large twin power scrapers are the most effective way of undertaking prestrip operations.

Jan 1, 2003

By Pollard D, Meadows N

The presence of impurities which are electropositive to zinc in acid zinc electrolyte causes changes to deposit morphology and reduced current efficiency. Glue may be added to control some impurity effects, but assaying for animal glue concentration is difficult and seldom done. Measurement of the activation overpotential for zinc deposition by cyclic voltammetry is used in some plants to monitor electrolyte quality and control glue additions.The deposit morphology and current efficiency of zinc deposition from commercial electrolyte were investigated for various glue additions in the presence of increased levels of antimony. Cyclic voltammetry was investigated as a method of optimising glue additions in the presence of antimony.Scanning electron rnicroscopy showed deposits characteristic of the impurity element present and the glue addition rate. Cyclic voltarnmetry measurements showed some correlation between current efficiency and activation polarisation potential. The importance of using tankhouse electrolytes where results are to be related to tankhouse operation was noted.

Jan 1, 1988

By L Chaffey, M Buckland

The minerals industry has enormous potential to positively contribute to sustainable development and many leading companies have concluded that their long-term success is directly linked to their ability to leave a lasting positive legacy. While there are many examples of success, there have been failures as well and much work has been done in recent years to define the role of the minerals industry in sustainable development and identify the key elements for success. In the past, our sector could point to the taxes and royalties it paid, the exports it generated and employment it created and felt confident that its contribution would be recognised and duly acknowledged. This is no longer the case. Critics of the industry have highlighted resource-rich countries that have failed to capitalise on their resource wealth and have arguably lower standards of living than their resource-poor peers û the æresource curseÆ hypothesis. Recent research has done much to clarify the factors that contribute to a countryÆs success or failure and all stakeholders in the industry now need to include these learnings in their approaches going forward. We know that our long-term success relies on embedding a company- wide approach to sustainable development into all aspects of our business operations. In this paper we highlight BHP BillitonÆs experience in the development and implementation of policies and systems designed to enhance our contribution to sustainable development. We detail the business drivers for excellence in this area and the key external codes and initiatives that have shaped our approach. The values-based BHP Billiton Charter, Sustainable Development Policy and associated Health, Safety, Environment and Community (HSEC) Management Standards are central to our approach. Implementation is reviewed through our HSEC audit program. One area in which we have placed particular emphasis is our approach to community development. BHP Billiton has a corporate target to contribute one per cent of its pre-tax profit on a three year rolling average to voluntary community programs. As our profit stream has increased with the minerals boom this is approaching an A$100 million commitment. In our paper we detail how we are working to ensure we maximise the value of this contribution for our communities and our shareholders.

Jan 1, 2006

By S Joyce, Z Agioutantis, D van Zyl, D Shields

Over the past 15 years, the mining industry has begun to incorporate the concepts of sustainable development and sustainable mining practice across the life cycle of mineral operations. This requires addressing economic issues, community impacts and concerns and environmental protection, and is captured in part by the phrase ‘design for sustainability’ (McClellan et al, 2009). Over the same period, the industry has seen a gradual decline in ore grades for many mineral commodities. As a result, large volumes of tailings and mine waste rock are being produced around the world, and it is expected that the annual production volumes of these materials will increase, even if there is not a significant change in the demand for materials.Another related thread of change has been the realisation that societies need to move away from linear economies (raw materials, production, consumption, disposal) towards more circular ones. This will help societies become more resource efficient, which is defined by the United Nations Environment Programme as reducing the total environmental impact of the production and consumption of goods and services, from raw material extraction to final use and disposal. The goal is to create more with less and deliver greater value with less input. Circular economies require thinking in terms of the waste hierarchy (reduce, reuse, repurpose, recycle, recover, landfill).The challenge is that the waste hierarchy was originally designed to address embodied mineral content in products rather than mine waste and tailings generation. It will need to be reconsidered in a mine life cycle context, focusing on a value-based conception of waste (Van Ewijk and Stegemann, in press).In parallel to these changes, it has remained an imperative in the mining industry to dispose of these waste materials as economically as possible while protecting the environment. Single handling of these materials has been the main target, which reduces the life cycle costs of their management but may make reuse of waste and tailings technically more difficult or economically infeasible.This presentation explores a rethinking of the large volume earthen material waste issue at mines. The underlying theme is that some or all of these materials can be valuable resources for the future that can positively contribute to sustainable development. These resources can offer economic gains to firms, communities and societies; contribute to environmental well-being; enhance social interactions with the previously mined landscape if handled properly; and, with proper policies in place, reduce governance commitments. Each of these topics will be briefly explored. This will be followed by a discussion of approaches to manage design and operations to allow future resource recovery.CITATION:Van Zyl, D, Shields, D, Agioutantis, Z and Joyce, S, 2015. Waste not, want not – rethinking the tailings and mine waste issue, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 7–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

The first stage in process design for coal preparation is a study of the coal seam and its associated features followed by an examination of the mining method to.be employed and the coal market requirements. Normally benefication is based upon the differences in relative densities of the coal constituents and asso- ciated ash forming components. Since initial liberation is obtained at a relatively large particle size, the size to which coal is crushed is more subject to the market requirements than to liberation studies. It is possible to estimate energy requirements for comminution and recoveries and product grades can be cal- culated following the interpretation of standard laboratory tests. Numerous units are available for the separation and concentration of the components of run of mine coal in- cluding jigging, dense media separators, and for the finer particle size fractions, flowing film separators, dense media cyclones and froth flotation.

Jan 1, 1975

Maintaining and improving the economics of open pit mining in the future requires understanding of the characteristics of open pit mining that are different to other mining or business activities, designing mines in the first place to be less susceptible to changes in these important characteristics, and adopting strategies which yield reliable returns despite unforeseen change. Planning and production personnel require guidelines and performance standards that are based on sound economics not solely on production criteria. The guidelines adopted for long-term implementation must assume a declining price for mineral products along with declining real costs, with research efforts directed at development of both evolutionary and revolutionary ideas aimed at implementation. Decision-making must focus on risk and probability criteria rather than just simple return-on-investment criteria, and the approach for management of personnel must support the higher level of communication essential for fast decision-making in the new environment of continual change.

Jan 1, 1992

By D Corley, J Moore, M Grant, A, W R

Resource estimates are the corner stone of technical and investment decision-making. Prior to mining, resource estimation uncertainty has the greatest potential to lead to poor investment decisions, despite a significant component of resource estimation uncertainty being unknowable at this critical stage in the mining cycle. This presents a conundrum to the resource geologist in terms of risk evaluation and resource classification. Ahead of mining, there is normally considerable focus on drill hole spacing analysis to determine the ‘optimal’ drill hole spacing, taking grade and geological continuity into account; cost-benefit analyses balance improved resource definition against cost; the law of diminishing returns and the exponential cost increases acting together as spacing is reduced. Typically, a lower limit to the drill hole spacing is identified. After completing the resource drilling to an agreed spacing, resource estimation is then undertaken. At this point it is common to attempt to bracket the resource estimation uncertainty. In many cases conditional simulation is used, based on a modelled, but largely assumed, variogram model. It is also assumed that the histogram of the available drill hole sample data is representative of the in-ground mineralisation. The purpose of this paper is not to diminish the importance of drill hole spacing and simulation studies, but rather to illuminate an important aspect of estimation uncertainty that, although previously recognised, is typically overlooked – the question of how representative the available data set is in characterising the true (but unknown) distribution of mineralisation. To do this, we lift the lid on one of OceanaGold’s former operations, the mined-out Globe Progress Mine, by resurrecting a high quality, close-spaced, reverse circulation (RC) grade control data set. The Globe Progress Mine is within the West Coast Region of New Zealand, it was closed and transitioned to rehabilitation in 2016 and is now known as the Reefton Restoration Project. The exhaustive Globe Progress grade control data was used to repeatedly ‘redrill’ the deposit by extracting 35 m × 35 m spaced subsets from the original 5 m × 5 m spaced grade control data. Utilising closely spaced grade control data removed the need for assumptions regarding short range continuity, which are necessary with forward-looking analyses that are based upon broader spaced resource drilling. The extraction process used a nearest neighbourhood algorithm, repeatedly moving the origin in 5 mE, or 5 mN increments. Individual resource estimates were then completed for each of the extracted drill hole data sets (49 in total) as well as a grade control estimate based upon the exhaustive data set. Whilst the data unpinning each of the 49 estimates changed, the geological assumptions, variography, and modelling parameters remained constant. This approach was taken to isolate the impact of changing the input data. The 49 estimates were then compared against each other and the grade control estimate. The mean of all 49 sensitivity estimates was close to that of the grade control estimate in terms of contained gold, tonnes and grade. Whilst it is acknowledged that the grade control estimate itself is subject to some degree of estimation uncertainty, the close match between the average of the 49 estimates and the grade control estimate suggests that the resource estimation methodology is reasonable and appropriate. Whilst this comparison is important, the focus of this study is on the component of estimation uncertainty related to the underlying data, and this is reflected in the spread across the estimates. The spread across the 49 global estimates (highest to lowest) for this particular Mineral Resource Estimation Conference 2023 | Perth, Australia | 24–25 May 2023 142 case study was found to be significant (approximately 20 per cent in grade and metal) and that is attributable solely to the underlying data. This exercise quantifies a component of the estimation uncertainty that is inherent to all drill hole data and is distinct from the uncertainties associated with modelling methodology choices, sample and subsample quality and drill hole spacing-related interpolation uncertainty. Importantly, this uncertainty is unknowable prior to mining; we can only directly compare the resource drill hole data against grade control data after mining has taken place. For the case study, approximately 65 per cent of the estimates fell within 5 per cent of the grade control estimate for contained-gold, suggesting that for many projects the histogram of drill hole data is unlikely to differ noticeably from that of the in-ground resource. However, about 15 per cent of the estimates in this study differed by more than 7.5 per cent, suggesting that a not-insignificant proportion of estimates will be materially compromised. Whether or not the available drill hole data is representative comes down to the ‘luck of the draw’ and cannot be known at the time of resource estimation. Given the challenge of attempting to evaluate forward-looking estimation uncertainty, a component of which that can only be quantified retrospectively, what should we do as resource geologists? What are the implications for risk evaluation, resource classification and reconciliation? Furthermore, without rigorous post-mining data checks, resource geologists may conflate suboptimal modelling with the shortcomings of the underlying data. An example of this problem is discussed in the following section.

May 24, 2023

By Ritchie AS

The principles of chromatographic and electrophoretic separations are described in simple non-mathematical language. Brief details of the analytical procedures and of equipment are given. Partial analyses of rare earth elements in monazites from four localit- ies in New South Wales are compared with analyses from other localities. The presence of uranium in two of the monazites is recorded. The occurrence of rare earths in nature is outlined and its geological significance is indicated, A low capital cost method of analysis of rare earths in monazites is Introduced.

Jan 1, 1972

By D R. Anstey

The mining of magnetite iron ore in Western Australia will generate large volumes of waste rock and tailings over many decades. The need to dispose of these materials will result in massive waste landforms that will require significant planning and management. The formation of comparable man-made landforms is relatively common, as exemplified through past practice in gold and iron ore (haematite) mining. Unfortunately, the performance of these landforms, with respect to long-term stability (erosion resistance), the release of low pH seepage water and aesthetic impact, has commonly been disappointing and environmental legacies have been created as a result. Lessons that have been learnt from past, large mining operations indicate that there is a need to rethink the methods of waste disposal and landform development applied to magnetite mining. The environmental compliance criteria applied to magnetite mines for the storage of tailings and waste typically include minimising dust generation (particularly as the tailings and mine waste may contain asbestiform minerals), control of silt, minimising visual intrusion and management of potentially acid forming materials. In addition, the climate of Western Australia and the paucity of both surface and groundwater in the vicinity of the magnetite mines frequently necessitate water consumption to be minimised. This paper discusses the potential to co-mingle magnetite mining waste streams in a variety of ways to concomitantly satisfy the environmental compliance criteria and the operational requirements of the mine. These methods include co-mingling of coarse tailings and waste through dry-stacking, deposition of tailings as a paste, co-disposing of all wastes to form an integrated landform and the co-mingling of all waste streams to produce PasteRockTM (a blend of tailings paste and crushed waste rock). The paper demonstrates how these techniques can be applied to the magnetite mining industry to provide better outcomes than might be achieved using more conventional techniques, currently employed in large-scale mining operations.

Jan 1, 2009

Hydrometallurgy has a history of over 300 years with copper leaching and cementation having been exploited in Spain as far back as 1670. Since then, hydrometallurgy has become an integral, expanding branch of extractive metallurgy. This paper reviews major developments in hydrometallurgy over the past century with emphasis on recent commercial developments and their impact on the mining and metals industries. The environment in which these developments has taken place has changed significantly in the past two decades and many factors, often non-technical, have emerged as constraints on the operation of existing plants and the expansion and development of new hydrometallurgical operations. Finally, a number of possible new developments that will shape the future of hydrometallurgy in the new millennium are discussed, particularly as they relate to the assimilation of technical advances in other areas of science and engineering. The impact of current trends in the education of hydrometallurgists and the provision of research in support of these future developments is also addressed.

Jan 1, 2000

By R M. Yanamandra, S K. Tripathy, N Mangadoddy, P Sudikondala, P Ankireddy

Spiral concentrator is one of the most commonly used gravity concentration devices in mineral processing. The particles are classified based on their specific gravity and size. The present work analyses the experimental and numerical investigations of the water flow field, such as fluid depth and free surface primary velocity of two high gravity spiral concentrators at different flow rates. The measurement techniques use a flow depth gauge and flow visualisation technique adapting lycopodium powder as the tracer. Flow features in terms of liquid depth and primary velocity at the free surface of the flow are captured across the trough in two different high gravity spirals. A highspeed motion camera with an imaging frequency of 5400 frames per second and 768 × 768 pixel resolution is utilised to track the tracer particles in the liquid flow on the dark surface background. Further, the two-phase flow is studied numerically on high gravity spirals based on the volume of fluid (VOF) approach utilising the RNG k-ε model and Reynolds Stress Model (RSM) for predicting the fluid flow on trough surfaces such as water depth and free surface primary velocity. The CFD predictions of the flow field for the two spirals are attempted to validate against experimental data. The high gravity spiral concentrators show lower flow depths and free surface primary velocities but steep velocities on the outer trough zone compared to that of low gravity spiral concentrators (conventional coal spirals). Among the computationally tested high gravity spirals, higher pitch and higher secondary slope design shows greater flow characteristics.

Aug 24, 2022

By L MacDonald, D Molver, D Pepper

Increasing contamination/impurity levels (including arsenic, antimony, mercury etc.) of concentrates is an issue of global commercial and health / environmental significance. With increasing environmental pressures at smelters, penalties for contaminants in concentrates continue to rise, accompanied by lower reject limits. There is a strong incentive for miners to investigate alternative means to remove contaminants in order to increase the value of complex ores and concentrates. This paper discusses the global problem of contamination in complex ores and concentrates, how the Toowong Process technology is a potential solution to this problem, and the opportunities this technology brings to the business of dealing with deleterious elements. CITATION: MacDonald, L, Molver, D and Pepper, D, 2018. The Toowong process for treatment of complex ores, in Proceedings Complex Orebodies Conference 2018, pp 119–121 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Stanton RL

Stratiform lead-zinc mineralization in the Soldiers Cap Group and Kuridala Formation of the Mount Isa Inlier is closely associated with iron-rich sedimentary units or "iron formation", and has many similarities to the Broken Hill deposit in New South Wales. Both the Soldiers Cap Group and the Kuridala Formation have been intensively explored for deposits of this type since the early nineteen- seventies. A mineralized belt of at least eight significant prospects has been identified, of which the Pegmont deposit is the largest and best known example. In most cases the mineralized horizons contain banded galena and sphalerite within a gangue of predominantly quartz-garnet- pyroxene-amphibole rock, sometimes containing a variety of other metamorphic silicates, and apatite. Chemically, the mineralized horizons are distinguished by higher than usual levels of one or more of total Fe, MnO, CaO and P205. Interpretation of patterns of mineral- ization within the belt is based on the Pegmont deposit, where a model of base metal sulphide deposition within restricted basins of iron-rich chemical sediment has been developed (Stanton and Vaughan, 1979). Broadly, the model envisages the deposition of higher grade lead-rich mineralization in the basin centre position, lower grade zinc- rich mineralization in a basin intermediate position, and much weaker copper-rich mineralization in a basin edge position. These three positions reflect a laterally continuous arrangement of silicate microfacies within the original iron-rich sediment.

Jan 1, 1984

Traditional techniques for extracting pillars in thick underground coal seams in India are reviewed. Problems encountered are principally control of roof strata and low recovery. Recently developed mechanized methods and projected newer techniques are discussed.

Jan 1, 1986

I would like to build on the keynote address given by Peter Stoker to the Fourth International Mining Geology Conference (2000) entitled æThe Role of the Mine GeologistÆ. He concluded that à the important aspects of the professional contribution of a mine geoscientist to a mine operation include: The geoscientists prime task is to maximise the profitable extraction of the ore deposit on which they are working û that is to add value. They must maintain and develop their own expertise. By ensuring a truly professional approach to all they do, they will provide the best service to the community, to their company or client, their shareholders and their family or close associates. In that process they will also assist in protecting themselves in this increasing litigious world. I intend to build on these points and, in particular to expand on what it really means to take a truly professional approach to mine geology. Mine geology is different from other forms of geological practice. As a mine geologist you are the advocate for the orebody. After all the orebody is the one thing that is unchangeable.

Jan 1, 2003