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By J Levett, O Rondon, I Glacken

Reporting Codes are not prescriptive on methodologies to report or classify Mineral Resource Estimation results, but the assessment of risk and uncertainty is required, and is likely to be increasingly important in future Code updates. The 2012 JORC Code indicates that relative confidence in tonnage-grade estimations should be considered for classification, and that there should be a discussion of relative accuracy and confidence levels in the Mineral Resource Estimate. These considerations are also relevant to the drill hole spacing required for various classification categories, along with other geological and data quality criteria. This paper summarises the theory, principles and current practice of various drill hole spacing analysis techniques for both achieving a desired level of resource categorisation and for optimising grade control or resource drill-out costs. The authors provide practitioners with a guide in their use to assess uncertainty and relative accuracy, as illustrated by a number of case studies. While all drill hole spacing studies rely on the assumption of consistency of the continuity model from current to future drilling, the range of methods available provide much more objective outcomes than previously adopted ‘rules-of-thumb’.

May 24, 2023

By Fink ST

Management requires up-to-date information on the activities of an enterprise in order to maintain control and to assist in decision-making and planning. In today's environment it is essential that this information is immediately available and in an easily assimilated format. If this is not the case, management is forced to make decisions based on intuition and past experience. At Mt Newman Mining Co, a computer application has been developed and implemented with the objective of providing this type of information to management. The Key Parameter Reporting System (as the application is known) allows for daily (constant) on-line capture of selected production statistics, safety statistics and free format textual comments relating to topics such as industrial relations, major maintenance and other pertinent news. Information can be retrieved,'and displayed or printed in either a tabular or graphical format. All senior managers have colour visual display units in their offices for immediate access to the system. Access to selected sensitive information is controlled. All company staff are able to retrieve unsecured information from the system via visual display units installed in all company Locations.

Jan 1, 1983

Iron formation-hosted iron ore deposits account for the majority of current world iron ore production and consist of three classes: unenriched primary iron formation with typically 25 to 45 wt per cent Fe; martite-goethite ore formed by supergene processes, with abundant hydrous iron oxides containing 60 to 63 wt per cent Fe; and high-grade hematite ores thought to be of hypogene or metamorphic origin overprinted by subsequent supergene enrichment with 60 to 68 wt per cent Fe.Individual iron ore deposits range from a few millions of tonnes to over two billion tonnes at >64 wt per cent Fe, although most are within the range of 200 to 500 Mt. In the Hamersley Province of Western Australia, martite-goethite ores are largely developed in the Marra Mamba Iron Formation, although high (>0.08 per cent P) phosphorous mineralisation is also well developed in the stratigraphically higher Brockman Iron Formation. Whilst the vast majority of high-grade microplaty hematite ore is best developed in the Brockman Iron Formation, this paper provides the first textural evidence of locally significant microplaty hematite mineralisation in the Nammuldi Member of the Marra Mamba Iron Formation, in the Chichester Ranges at the Christmas Creek, Cloud Break and Mount Nicholas prospects. Petrographic studies have identified a high-grade Fe texture composed of nanometre scale plates of hematite in mineralised sections of primary microplaty hematite deposits in the Pilbara and elsewhere, well below the normal depth of weathering or dehydration. The population of nanometre to micrometre scale hematite plates is interpreted to represent various stages of nucleation, crystallisation and progressive growth of hematite from the primary ore-forming fluid in areas that were once iron-rich carbonates or silicates in the BIF.

Jan 1, 2005

By K Clode, J Al-Shdifat, S Daykin

Planning for a circular economy allows for previously untapped market opportunities to be explored, resulting in new, innovative revenue generating opportunities, while also reducing environmental impacts. In particular, rare earth elements (REE) are in rising demand as they are key components of over 200 products across a wide range of applications (Xie et al, 2023) including renewable energy technologies. There is a geographical disparity in deposits, with China being the top producer, generating 70 per cent of global production in 2022 (Laboure, 2023). This single dominating source has created supply chain concentration and hence supply risks for other nations, providing a driver for finding alternative sources, such as mine-influenced water (MIW) and tailings. In this study, Isle presents a robust due diligence methodology for undertaking a global horizon scan into REE recovery technology, for a large mining company, from tailings decant water on a specific site. Previous studies of the tailings decant water at this site had shown potentially significant concentrations of both heavy and light REE, but challenges such as high flow, very low pH and high concentrations of iron had previously made recovery unfeasible. Due to these challenges, the horizon scan focused on technologies that had the potential for selective recovery, despite the challenges with water quality, and considered a range of Technology Readiness Levels (TRLs). This included an adsorption-based process that has the potential to selectively separate individual REE, and a polymer based selective flocculation technology.

Sep 1, 2024

Gravity concentration of tin at Renison Limited uses tables and spirals to treat the various coarser fractions produced from sulphide flotation tailing. An acceptable final tailing cannot be made from one pass over the tables and spirals and therefore the tailing from these separators is reground and combined with the sulphide flotation tailing as the feed to the classification section. The gravity section became increasingly overloaded in the years preceding 1976 due to efforts to maximize tin recovery to the gravity concentrate. In April, 1976, two 2DSV Reichert cone concentrators in series were installed to treat the table and spiral tail- ing stream, prior to regrind, to scavenge a small tonnage of hard, coarse low tin grade material for rejection to final tailing. Gravity section loadings were decreased markedly, allowing operator attention to be directed more to table performance than to spillage collection. An increase in mill throughput of approximately 15% was possible following the commissioning of the Reichert cones. The cones are currently operated to make the minimum tonnage of tailing consistent with reasonable- gravity section loadings.

Jan 1, 1978

By K Watanabe

A relational database in which its complex contents can be navigated through a map interface (ie spatially enabling) is relatively a new concept yet attractive for geoscience fields. This concept is made possible using the new breed of geographic information system (GIS) that utilises component object model and relational database management system. Such sophisticated yet open and highly interoperable platform makes possible the integration of data management, analysis, and modeling processes into single workflow. Taking benefit of this technology trend, several initiatives emerge in geoscience to establish digital data models, such as the petroleum industry, the North America digital geologic map data model, and the ESRI geology data model. The mining industry unfortunately has not followed same paths due to the lack of data model and standards in its history. This paper presents an effort on establishing a digital data model for mining-related geoscience databases. The aim is to promote several standards by proposing a preliminary data model and demonstrating that the model is working for the mining business datasets. The case study is the island of Java, the western part of the Sunda island arc of Indonesia. Many types of datasets, such as geologic maps, topography, mineral deposits, structures, geochemical and geophysical data were dealt with and were transformed relational geologic databases of Java using the new Geodatabase geographic data model. Intelligent GIS tools were investigated for geologic applications, ranging from generic to specific purposes. Subtypes and domain were used to set up constraints, while topology rules and relationship classes were used to create links among data layers. The linear referencing system was used to model drillhole data. The current results show that the generic GIS and relational database can handle typical tasks related with mining business datasets. A preliminary data model is finally suggested.

Jan 1, 2004

By B J. Monaghan, R J. Longbottom, D J. Pinson, S J. Chew

Recycling steel plant by-products is a critical issue for achieving both environmental and economic sustainability of integrated steel plants. A key steel plant by-product stream is dust from basic oxygen steelmaking (BOS), which can be recycled back to the BOS vessel as iron units and to aid slag formation. The major limitations for its recycling are zinc and the uncertainty in zinc speciation of the dust. This uncertainty affects the amount of dust recycled and how it interacts with the slag during processing. BOS dust in stockpiles can undergo self-sintering reactions that oxidise the iron-bearing components. As this occurs, zinc (or oxide) may combine with iron oxides to form a zinc-iron spinel solid solution phase. Knowing which zinc-bearing species are present in the BOS dust is a key aspect in understanding and developing an efficient recycling process for the dust. To overcome difficulties associated with phase identification in the BOS dust (both fresh and selfsintered), particularly the magnetite-zinc ferrite spinel solid solution using X-ray diffraction (XRD) / scanning electron microscopy (SEM) / energy dispersive spectroscopy (EDS), high end characterisation tools, transmission electron microscopy (TEM) and Mössbauer spectroscopy, were also used. Such an approach allowed improved phase identification of key zinc- and iron-bearing phases that were not previously resolvable. The zinc in fresh BOS dust was mostly present as extremely fine separate particles of zinc oxide, attached to the iron particles. These extremely fine particles were <10 nm in size. Additionally, a small amount of zinc ferrite was also identified within the sample (most likely contained within a magnetite-zinc ferrite spinel solid solution). However, the zinc in the self-sintered BOS dust, was found to be present entirely in a magnetite-zinc ferrite spinel solid solution. While this spinel phase had been previously identified by XRD, it was not clear that it contained zinc. The Mössbauer results provided definitive evidence of zinc within the spinel phase.

Jun 19, 2024

The Bellambi Coal Company Limited com menced longwall mining at South Bulli Colliery in 1965. At present it operates three long- wall units in two seams. Although results to date have been less successful than planned, it is apparent that this type of mining has tremendous potential in the particular conditions at South Bulli. Massive sandstone strata above the Bulli seam is the controlling influence on face conditions. The earliest equipment proved to be inadequate and the Company has progress- ively replaced and upgraded the roof supports and ancillary equipment so that the present units are capable of producing high and consistent outputs.

Jan 1, 1976

By H Q. Zhang, M C Chai, W Fu, H Y Chen, L M. Wei, Q J. Yang

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Fozichong deposit – located in the south-western segment of the giant Qinhang metallogenic belt, South China – is a large-sized lead-zinc polymetallic deposit. This deposit contains two main ore districts, termed as the Guyi ore district in the north and the Hesan ore district in the south respectively. We present an integrated data set on sulfide minerals, fluid inclusions and stable isotope (H-O-S-Pb) geochemistry to better understand the features and genesis of the Fozichong deposit.Field and paragenetic relationships indicate three mineralisation stages forming the early (Po+Sp+Gn+Ccp+Py+Di+Ep+Qtz), middle (Sp+Gn+Ccp+Py+Ep+Chl+Qtz) and late (Gn+Sp+Py+Qtz+Cal) sulfide assemblages respectively. Mineral chemistry – particularly S/Fe and Co/Ni ratios in pyrite, Zn/Fe, Zn/Mn and Zn/Cd ratios in sphalerite and Pb/Ag ratios in galena – indicates a magmatic association for the sulfide minerals.Quartz and calcite coexisting with the sulfide minerals of various stages host abundant fluid inclusions. Quartz in the early stage contains two- or three-phase CO2-H2O and liquid-rich aqueous inclusions, which have homogenisation temperatures of 162~365°C and salinities of 2.9~17.8 wt per cent NaClequiv, whereas quartz and calcite from the middle and late stages are dominated by two-phase, liquid-rich aqueous inclusions that have slightly lower homogenisation temperatures (153°C~320°C) and much lower salinities (1.0~6.0 wt per cent NaClequiv). Hydrogen isotopes (dD = -59‰~-41‰), analysed using fluid inclusion waters from quartz and calculated oxygen isotopes (d18OH2O = -5.47‰~4.00‰) for the equilibrated ore fluids, indicate that the ore-forming fluids may have been sourced from magma and mixed with groundwater in the late stages. Sulfide minerals have d34S values of 2.3‰~4.3‰, consistent with a magmatic-derived source for sulfur. Lead isotopes (206Pb/204Pb = 18.592~18.794, 207Pb/204Pb = 15.648~15.864, 208Pb/204Pb = 38.909~39.580) confirm that lead and, by inference, zinc were mainly derived from magmatic rocks, with subordinate contributions from sedimentary rocks.Various lines of evidence support that the formation of the Fozichong deposit has close genetic association with the granite porphyry intruded in the late Yanshanian period (106 Ma), and it can be classified as a magmatic hydrothermal type lead-zinc deposit. We propose that the Hesan and Guyi ore districts may represent the proximal and distal products of a magmatic – hydrothermal system respectively.CITATION:Fu, W, Zhang, H Q, Chai, M C, Yang, Q J, Chen, H Y and Wei, L M, 2015. Genesis of the large-sized Fozichong lead-zinc polymetallic deposit, Guangxi, south China – constraints from the sulfide mineralogy, fluid inclusions and isotope geochemistry , in Proceedings PACRIM 2015 Congress, pp 609–614 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By P Grouhel

In the recent years several new blasting technologies have come into use in surface mines. Electronic initiation, low-density emulsion explosives and modelling software are in regular use throughout the world. In Australia, these new technologies have achieved significant application, largely in open cut coal mines where more than 20 per cent of blasting is now conducted with electronic initiation systems. These new techniques have contributed to the vast improvement in blasting outcomes evidenced by increased recovery of saleable product and faster excavation rates. In large surface mines, OricaÆs unique combination of electronic initiation systems, bulk emulsion explosives and modelling software can be harnessed to target critical value outcomes. This includes targeting better fragmentation, increased ore uncovery rates and better wall stability û all adding to improved mining operation profitability. Orica Mining Services have combined these technologies into a set of offerings called Blast Based Services (BBSÖ). The paper describes applications of these new technologies and possible benefits in large surface mines.

Jan 1, 2007

By B W. Atkinson, J Docherty

An Australian Working Group has been compiling a guide for operators to use in order to improve the efficacy of their routine and non-routine sampling tasks within their coal preparation process. The guide focuses on unit operations within the process, and not conveyor belts or transfer stations that are adequately covered by the existing Standard ISO 13909.Representative sampling of unit operations is generally an after-thought following plant construction, whether that be a result of oversight, or more commonly, capital cost minimisation during initial construction. Minimising capital cost by avoiding adequate sampling systems is generally a poor decision, since the result is a process that cannot be adequately measured, meaning that it cannot be adequately managed and optimised.The use of the term ‘guide’ rather than ‘standard’ is intentional. Practical means of sampling unit operations within existing plants generally relies on a compromise between sample representativity (minimisation of bias) and sampling feasibility. The guide does not endorse poor sampling practice, but instead offers practical guidance to overcome, to the extent reasonably possible, real-life limitations.When it comes to sampling any particular process, it is almost always necessary to make a professional judgement as to whether or not the proposed samples are likely to be sufficiently representative such that the sampling will be worthwhile. Such judgement needs to be exercised by personnel who understand the principles of sampling, as they apply to the stream being sampled. There are many circumstances where available methods for sampling of a particular stream will be meaningless, and in such circumstances analytical data from that sampling will only serve to propagate poor decision-making.This paper outlines the approach for the guide, the areas it covers and the approaches adopted for different types of unit operations and associated equipment configurations.CITATION:Atkinson, B W and Docherty, J, 2017. A practical guide to sampling in coal preparation plants, in Proceedings Eighth World Conference on Sampling and Blending , pp 241–246 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By R Thompson, D Tulloch

"Wet-weather or 24×7 wet-trafficability is a commendable design objective for unpaved mine haul roads, but practically often difficult to achieve, due both to the road sheeting material selected, and also its breakdown under the action of traffic and environment. Accidents allied to wet-trafficability issues, either due to rain or often more commonly, over-watering of mine roads, is increasing and especially the loss of control or uncontrolled vehicle movements categorisation. The dominant system failure is that once vehicle control is lost, control cannot be regained.The friction supply, or ‘skid resistance’ of a mine haul road sheeting is critical to the safe operation of the road and data has to be collated concerning the variation of friction supply with sheeting material engineering or indicator properties. In the light of the paucity of data existing in this field, this paper presents the contributory research that informs the development of improved and validated unpaved mine road friction supply estimates, based on a number of mine site evaluations across a range of sheeting material types and characteristic parameters, leading to improved predictive models of friction supply.Results from this preliminary review will enable operators to assess their road sheeting materials, improve and validate unpaved mine road friction supply estimates. This will contribute to improved road design, management and 24×7 operability decisions and contribute to a reduction in heavy vehicle loss of control incidents on gravel-surfaced mine haulage roads.Citation:Thompson, R and Tulloch, D, 2016. What's Stopping You? The Role of Sheeting Material Selection in Safe Haulage Operations, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 253–264 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By J P. van Dijk, M Munro

Discrete vein modelling presents an innovative geology driven 3D modelling method for quantification of vein hosted mineral deposits, with far reaching potential for critical mineral supply and low impact resource extraction. By integrating key geological drivers with advanced discrete fracture network modelling, the DMX protocol (launched in 2019) converges to a more realistic representation of complex vein systems in three-dimensional space. The approach insights greater geologic reasoning in distributing mineral grades where vein boundaries are already defined. This presents a viable alternative to existing modelling and estimation methods and has important implications for mineral resource estimation and reporting. Further implications are discussed, where the enhanced understanding of complex orebody characteristics can potentially be used in optimising mining and mineral processing, supporting more sustainable and efficient mining practices.

Sep 1, 2024

By S K. Panda, M A. Van Ende, S Chatterjee

Tata Steel Netherlands (TSN) aims to reduce its CO2 emissions by 35–40 per cent by 2030 and become CO2 neutral by 2045. A first step to reach these targets is via the utilisation of an Electric Arc Furnace (EAF), which will run on a mixture of high proportion of Direct Reduced Iron (DRI) and scrap. For an EAF operation, optimisation of slag chemistry is important to achieve the right mix of basicity (for refining especially dephosphorisation), foaming, volume (rate) and refractory life. Slag composition and rate can vary widely depending on the process variables like charge mix, charge composition, feeding rate, oxygen lancing, external carbon injection/addition, fluxing and refractory erosion/corrosion. Moreover, it is important to note that the slag composition and rate are ‘transient’ parameters and change throughout the heat. This makes all the dependent phenomena and/or outcomes transient as well. To describe all these effects simultaneously and be able to realistically simulate the EAF operations, a validated dynamic process model is important in the absence of real plant data. In this study, a validated dynamic EAF process model based on the concept of Effective Equilibrium Reaction Zone (EERZ) has been utilised to analyse the impact of high DRI industrial scale EAF operations on the transient slag characteristics – including slag volume (rate), composition, phases, solid fraction and viscosity. Simultaneously, the model is able to predict the impact on steel and offgas characteristics. Case studies were performed with 70 per cent DRI:30 per cent scrap mix considering both low and high-grade DRI. Both melting and refining aspects of the process including continuous feeding, arcing program, carbon addition, fluxing and oxy-lancing were considered.

Jun 19, 2024

By Cunningham CG

Many epithermal gold-silver deposits areknown to occur in the Neogene-Quaternary volcanic complex of the central Andean region of southern Peru, northern Chile, western Bolivia, and north-western Argentina, an area of about 300,000 km2 where these volcanic rocks constitute the dominant cover. Some of the gold-silver deposits were mined during Spanish colonial times, as early as the 16th century,- whereas others were not discovered until the 19th and 20th centuries. The extraordinary gold-silver potential of this young volcanic complex, however, was not recognized until the 1970&apos;s when the phenomenal increase in gold and silver prices stimulated new exploration. New discoveries were made, chiefly in southern Peru and northern Chile, of high-grade ores in old mining districts and large low-grade ore bodies, both in old districts and in new areas having no history of mining activity. Many additional gold and silver deposits remain to be discovered within and beneath the young volcanic complex of this region.

Jan 1, 1990

Zinc concentrates from the newer mines and from proposed developments provide both opportunities and processing challenges to the conventional roast-leach electrowin smelters. These concentrates are often characterised by low iron, elevated silica, possibly high manganese, and levels of elements such as germanium which may cause concern. In addition, environmental constraints on residue disposal are forcing significant changes to some smelter practices. Iron in concentrate, and the resulting environmental impact of residue disposal are now major questions. However, normal concentrate tariff structure provides a disincentive against smelters taking high grade concentrate and oxide fume. Processing technology to cope with these changes is reviewed, as is de-watering and materials handling of ultra-fine concentrate. Within a few years, such fine concentrates will account for up to 1 000 000 t/y of contained zinc. New processing technologies including novel transport methods, siliceous leach circuits, manganese removal cells and front-end smelting will become significant in zinc smelting.

Jan 1, 1993

By M Liang, C Putzmann, D Gokaydin

The mining industry faces numerous challenges in swiftly evaluating and exploiting new mineral deposits to meet the escalating demand for critical minerals and metals. These challenges necessitate the adoption of innovative techniques and technologies to expedite development cycles and facilitate the efficient exchange of knowledge and expertise. Traditional mineral exploration methods rely heavily on data governance, visualisation tools, and expert interpretation skills, often operating in isolation and limiting the integration of valuable data and knowledge (Lindsay and Perrouty, 2019). To address these integration challenges and bridge the industry’s knowledge gap, the concept of a digital twin offers a holistic solution (Ahn, 2021; Nagovitsyn and Stepacheva, 2021).

Sep 1, 2024

By P Moarefvand, M Osanloo

The anticipated economic life of the mine, which defines the rate of mine production, is dictated initially by the design capacity of the mill/concentrator and the production capacity of the mine relative to the grade and tonnage of ore that can be encompassed by the pit design. A small pit will result in smaller investment and cash flow; in contrast, a larger size of pit will increase capital investment and annual revenue. Since open pit mine design and long-term production sequencing are essentially based on three-dimensional block models, changes in block dimensions leads to different mine sizes, and therefore changes in the mine life. The physical characteristics of the deposit, such as reserve tonnage and ore grade, affect the expected future revenues from the mining project, and consequently they affect the life of the mine. Large blocks will increase the recoverable ore reserves and production rates and hence increase the mine life. This paper discusses the effects of the block dimension on the commercial ore reserve, grade-tonnage curve and its effect on the production rate, ultimate pit size, mining cost and consequently the mine life. The result shows that block height is the most effective parameter governing the economical life of the mine.

Sep 26, 2011

By D Connelly

The Iron Road Limited Central Eyre Iron Project (CEIP) area, located on the Eyre Peninsula of South Australia, covers extensive Archaean iron formations that occur as coarse-grained magnetite bearing gneiss. The cumulative strike length, estimated from aeromagnetic data, is at least 95 km.The project is located in a grain growing area 185 km west of the existing iron ore and steel making operations of OneSteel at Whyalla. A narrow gauge railway built to transport agricultural products to the deep-water port of Port Lincoln, 175 km to the south, traverses the project area. A number of well-serviced rural townships are located nearby. Current activities include resource expansion drilling, extensive metallurgical test work, community consultation and a Prefeasibility Study (PFS) that commenced in April 2010.The PFS has encompassed the Central Eyre Iron Project, comprising the three significant iron occurrences (Warramboo, Kopi and Hambidge) and was completed in early 2011. Extensive test work programs and metallurgical modelling confirmed viable process options for the project, using simple off the shelf processing technology.Preconcentration by coarse cobbing yielded promising results, and is the key to reducing not only the capital expenditure but also the operating cost, in particular the power cost, which is the highest operating cost component of a magnetite benefi ciation plant. The ore is also amendable to high pressure grinding rolls (HPGR) processing. This offers a potential for further reduction of the energy requirements.Test work also confirmed that a high grade blast furnace quality concentrate (~68 per cent Fe) can be produced at a relatively coarse grind (P80 106 µm).

Jul 11, 2011

By V Rodríguez, M Hormaza, R J. Romañach, C Pinzón-de la Rosa

The authors have presented their ideas for developing a powder sampling device in the I-Corps™ program sponsored by the National Science Foundation (NSF). This is an intensive customer discovery program developed to increase the economic impact of the research sponsored by NSF.The I-Corps™ program requires performing at least 100 interviews with potential customers in various industries. These interviews are essential to establish the need for a particular product or solution, and identify potential commercialisation partners and competition. The interviews have revealed the absence of Theory of Sampling (TOS) principles in many companies. The interviews are designed to identify the difficulties associated with current sampling practices that do not meet TOS principles.The I-Corps™ program is a significant challenge for scientists who often avoid discussing a concept in fear of losing their research idea. The program teaches how to obtain information without releasing the important intellectual property related to a product development idea. The I-Corps™ methods have been used to discover the prevailing ideas on sampling in various industries.I-Corps™ also teaches how to present ideas to investors; another significant challenge for a scientist. We are currently learning to present sampling and TOS to investors and business development experts, and will share some of these experiences.CITATION:Pinzón-de la Rosa, C, Rodríguez, V, Hormaza, M and Romañach, R J, 2017. Theory of Sampling meets the National Science Foundation I-Corps™ program, in Proceedings Eighth World Conference on Sampling and Blending , pp 351–354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017