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By K H. Esbensen

The Theory of Sampling (TOS) has contributed significantly to chemometrics by allowing data analysts to become more aware of total measurement uncertainty as total sampling error + total analytical error. This has allowed a new view on, for example, validation of multivariate data models and their performance. This keynote focuses mostly on the reverse perspective: how can chemometric multivariate data modelling be of help in an augmented sampling context? The basic principles of multivariate data analysis are presented and application examples are outlined from several areas in the geosciences to facilitate answers to the question posed, including a geochemical multivariate anomaly concept defined by a multivariate background model. Applications from geochemical prospecting, geochemical mapping, environmental chemistry and anthropogenic outlier recognition are outlined, as are the interdependent relationships between geostatistical modelling (variographics) of singular variables versus linear combinations of a multitude of variables, in chemometrics called scores. The potential synergy between chemometrics and TOS is far from exhausted at this time; much work remains.CITATION:Esbensen, K H, 2014. Theory of sampling in a multivariate perspective – what can chemometrics contribute?, in Proceedings Sampling 2014 , pp 7–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By D Tanzil, H Jones

Every mine will close! Charting a profitable course through mine operations to acceptable mine completion requires that risk and opportunity management planning of the mine life begin as early as possible in the life cycle. Management targets and metrics are required to identify and navigate the course to successful mine completion based on economic, social and environmental criteria. This paper outlines the application of The Metrics NavigatorÖ principles to the life cycle of a mine site. In general, metrics are required to make key strategic ideas apparent, transforming those ideas into a manageable set of quantitative measures that guide communication and decision making. For example, the chemical industry has established metrics that focus on the life cycle impacts of its products and eco-efficiency of their processes. Other industry sectors have focused attention on workplace and community well-being outcomes. These management metrics are necessarily organisation-specific, aligned to stakeholdersÆ expectations and the strategic outcomes sought, as well as the cause-and-effect relationships underlying key issues. Recently, the Global Environmental Management Initiative (GEMI), a consortium of multi-national companies, developed The Metrics NavigatorÖ. The guidance document provides a structured process for assessing and developing metrics for key environmental, social, and economic issues based on business and stakeholder perspectives. It incorporates best practices learned from the chemical and other industry sectors and has since been applied to develop metrics that guide life cycle strategies. The paper examines how the life cycle of a mine site could benefit from experiences in other industry sectors where sustainability metrics have guided strategy. It considers the potential application of The Metrics NavigatorÖ process to the life cycle of a hypothetical Australian mine site using the processes that have been successful in other industry sectors.

Jan 1, 2009

For the past five years the University of Queenslandhas, through its various workshops, been preaching to Australia that there was a potentially hazardous situation from earthquakes for urban Australia. A few people outside The University accepted this, but largely the warnings fell on deaf ears.The 1989 Newcastle earthquake changed that per-ception. The most important lessons to emerge from Newcastle were (i)the realization that in continental areas small earthquakes cause widespread damage:(ii)the local geology of an area is of great importance in the damage done by an earthquake.These two factors clearly indicate that, in the future, we must take far greater account of the "Urban Geology" of an area. This paper discusses the need for urban geology and its impact on seismic risk and compares that with the traditional methods of assessing seismic risk.

Jan 1, 1990

By Garland W

Access to geoscience reference informa- tion including mining and mineral processing has increased considerably in the last five years in Australia. This has been due principally to the use of computer-based information storage and retrieval systems. The main reference data base for the mineral and petroleum industries and disciplines in Australia is the Australian Earth Sciences Information System (AESIS), cooperatively developed and coordinated by the Australian Mineral Foundation (AMF). AESIS is created on the CSIRO computing network (CSIRONET) which has a CYBER 76 host computer located at the CSIRO Division of Computing Research (DCR) at Canberra. Data entry was until recently carried out by AMF using a dedicated line through the Adelaide CSIRONET node to the CYBER 76 interactive system. Data entry is now done directly at the AMF on a DEC PDP 11/44 mini computer that is also a host work station on CSIRONET. Data collection via magnetic tape media input from other computer-based systems is under development. The software used for data entry and management of the data base was developed by CSIRO CILES Systems Development Group. For public interactive online use the AESIS data base is transferred by tape to AUSINET - the Australian information net- work run by ACI Computer Services, Melbourne, where the data base is converted to a form suitable for the IBM STAIRS software. CSIRO facilities at DCR Canberra are used to produce computer type-set camera ready products and output in microform, on magnetic tape or as graphic display. Keywords: Earth sciences information, Computer applications, Information storage and retrieval, AESIS, Data bases, Australia.

Jan 1, 1983

By S G. Li

Mine intelligent ventilation is an important guarantee to realise intelligent mining. It is the integration of the Internet of Things, big data, artificial intelligence, internet, cloud computing with ventilation technology, forming a complete ventilation system with intelligent perception, intelligent decisionmaking, intelligent emergency response and airflow control. In order to fully grasp the progress and trends of mine intelligent ventilation research in western China. The paper based on literature analysis and field application research, comprehensively expounds the main research and practical results of mine intelligent ventilation in western China, mainly analyses the development status of key technologies such as accurate and rapid determination of mine ventilation parameters, intelligent analysis and decision-making of ventilation and intelligent regulation of ventilation equipment, and introduces the field test or application of mine intelligent ventilation technology in western China. It lays the foundation reference for related research and improving the intelligent level of mine ventilation.

Oct 12, 2022

By C Morley, B Costello

In 2002 the Argyle Diamond Mine upgraded the process plantÆs recrush circuit to include a High Pressure Grinding Roll (HPGR), or High Pressure Rolls Crushers (HPRC) as they are termed in the diamond industry. HPGR have generated considerable interest over the last decade, though there are still technical/processing unknowns to its effectiveness as a primary diamond ore crusher.The upgrade of the Recrush circuit at Argyle Diamonds has gone a long way to answering some of the key questions, and thus it has reduced the unknowns to a level more acceptable to the industry.This paper focuses on the results from the HPRC at Argyle, in particular the performance of the studded wear surfaces, comparison of energy efficiency against traditional quaternary cone crushers and the resultant increased liberation. Issues that have arisen, including edge wear of the studded surfaces, will be discussed and the steps taken to reduce this issue are presented.

Jan 1, 2004

By Kuzmitch O, Morozov A

The main direction in the mechanisation in the mines of the Donbas and the USSR is long-face technology with complexes on the base of hydraulic supports. On the base of the 30 year old experience of exploitation of the coal clearing systems the serious data about the behaviour of the contained rock, display of underground pressure 'on longwalls and preparatory workings have been accumulated. Exploitation works in mines of the USSR are carried out at different depths: from 1000m to 1200m. There are 26 mines in Donbas, which exceed the depth of 1000m. It is the mines of Donbas, where is a rich experience of the exploitation of coal seams in various conditions. Besides, there are wide variations on the factors of the extraction thickness, depth of seam, angle of dip, occurrence of gas dynamics and others. In many scientific establishments, and in Donetsk Polytechnical Institute also, there are scientific research/results, which can be of interest for the coal mining countries.The volume of coal mining from longwall system-mechanised walls in Donbas became stable at the end of the 70s at level of 70 percent. All the efforts to increase this level have not given any notable results, not saying about the technical-economical data, which gradually deteriorate. It shows that positive progress in using the technology for the long walls is over and it is necessary to find new ways of mechanisation of coal winning.

Jan 1, 1991

By M McGeough

Following the success of calcrete sampling at Challenger, calcrete sampling has been widely adopted as the primary exploration technique for gold exploration, in the Gawler Craton. Calcrete is uniformly distributed over large areas and produces discrete gold anomalies. This allows drilling to focus on specific gold anomalous targets. However, despite widespread use of calcrete sampling, very little is known of the origin of calcrete in the Gawler Craton, and the link between calcrete gold anomalies and primary mineralisation. In an attempt to understand this association Lisa Gibbons recently completed an honours project at the Old Well Prospect approximately 45 km SSE of Tarcoola. Her work is part of a collaboration between CRCLEME, MESA and MIM Exploration. At Old Well, a calcrete anomaly (>10 ppb Au)covers an area approximately 7 km x 2 km with a peak value of 97 ppb Au. The study looked at the regolith as a whole, processes of its formation and nature of mineralisation within it. She was able to combine previous calcrete and drilling results with her own observations. The results from this study highlighted problems in relating surface calcrete anomalies to in situ gold mineralisation.

Jan 1, 1998

By M Jones

The past 100 years the mining industry can be characterised by a focus on increasing financial returns often to the detriment of social, human, manufactured and environmental capitals. Despite the sustainable development principles promoted by the International Council on Mining and Metals (ICMM), the Equator Principles and the African Mining Vision, which should have enhanced project promoters’ ‘licence to operate’ within a host community or nation, the industry has often failed to integrate proven innovations and best practices that enhance sustainability outcomes for mineral resource projects. This failure has led to delays, the abandonment of projects, with value destroyed for promoters, governments, host community and investors.The paper will outline the application of proven innovations, Enterprise Optimisation (EO), and Sustainable Operations (SUSOP®), during the pre-feasibility phase of a project. By determining the value of each capital before and after the application of proven innovations, the presentation will outline how and where value can be created across all five capitals over the life of a project or operation.The paper will demonstrate how the application of proven innovations significantly transforms the value-proposition of a mineral resource project or operation by generating additional value across all of the five capitals, reducing project risk, thus generating value for all stakeholders.CITATION:Jones, M, 2015. Fundamentally transforming the economic and sustainability signature of mining assets, in Proceedings Third International Future Mining Conference, pp 169–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By B Lumsden

During periods of high metal prices and strong metal demand tailings retreatment can be economic. Most tailings retreatment operations are technically challenging, low margin operations, because the easily recovered mineral has already been removed, therefore, process improvements can potentially yield large economic benefits. The Hellyer tailings dam was owned by Intec Ltd and contained 10.9 million tonnes grading 2.8 per cent zinc, 3.0 per cent lead, 88 g/t of silver, 0.16 per cent copper and 2.6 g/t gold. In November 2006 the Polymetals Group, as operator, restarted the Hellyer plant to retreat these tailings. Within a few months the operation had stabilised and Polymetals was meeting budgeted targets of throughput, metal recovery and concentrate quality. Polymetals and Intec then investigated methods that would improve the metallurgical result for this difficult to treat tailings. Since the tailings are fine-grained with 80 per cent <45 ¦m, magnetic aggregation of the paramagnetic sphalerite was evaluated. Magnetic aggregation of an oxidised tailings feed has not been tested before, nor had the technology been available when Hellyer ore was originally processed. Extensive statistical test work showed magnetic aggregation of the sphalerite fines in the zinc cleaner circuit increased total zinc recovery. The increase in the mean zinc recovery with magnetic conditioning was 3.63 per cent, at a statistical level of confidence of 97.8 per cent, and at the same mean zinc concentrate grade.

Jan 1, 2009

By J P. Jona, S R. Poulson, C H. Gammons

Spatial and temporal trends in water chemistry in the acidic (pH ~2.6) Berkeley Pit lake, Butte, Montana, can be explained by a newly developed iron-cycling model. Key elements of this model include: subaqueous oxidation of pyrite and other metal sulfide minerals by dissolved ferric iron, producing Fe2+ as a by-product; re-oxidation of Fe2+ to Fe3+ in the epilimnion, assisted by A ferrooxidans; precipitation of secondary ferric minerals (schwertmannite, jarosite) in the epilimnion; and replenishment of the Fe3+ concentration of the hypolimnion by seasonal lake turnover and gravitational settling and re-dissolution of ferric precipitates. Pyrite oxidation rates were approximated by using published rate laws and information on the Fe3+ concentrations (~5 mmol) of the Berkeley Pit as a function of depth. The results indicate that subaqueous pyrite oxidation may be releasing as little as 6 + 106 or as much as 600 + 106 moles of H+ each year to the lake; the large range reflects uncertainty in calculation of the specific surface area of pyrite in the flooded pit. This helps to explain the observation that the pH and metal concentrations of the Berkeley Pit have not improved with time since mine flooding began in 1983. Vertical cycling of ferric iron in the pit lake permits pyrite oxidation to continue in deep water, even in the absence of dissolved oxygen. This hypothesis is supported by preliminary stable-isotope data.

Jan 1, 2003

Teleseismic travel time residuals measured on 600-1000 km seismic arrays across the Rio Grande and East African rifts provide evidence for upper mantle low velocity zones beneath each rift of velocity contrast 6%-8%. Refraction studies show thinning of the crust below the rift axes. Regional uplift which extends hundreds of km either side of the axes, is isostatically compensated by negative density contrast at depth. Since the refraction argues against compensation by thickened crust, compensation in the upper mantle low velocity zones is suggested. Temperature effects alone can not explain the reduced velocities. Generation of a few percent of partial melt is the most probable source of the reduction. A passive extensional mechanism is investigated for the Rio Grande rift in which hot asthenosphere intrudes the lithosphere raising its temperature and generating moderate melting. It requires less than 1% extension to explain the melting but a prodigious 26% to raise the temperature from a pre-rifting continental geotherm to the solidus. Geological estimates find that extension is less than 10% over the uplift zone. Such a mechanism is possible only if the prerifting lower lithosphere geotherm lies closer to the solidus than that of stable continent. This is supported by the observed high heat flow in the Rio Grande rift uplift region which, given the long time constant for thermal diffusion, reflects elevated temperatures at depth well in advance of the onset of rifting.

Jan 1, 1987

This paper covers only the energy uses of natural resources and does not deal with non- energy uses, which in 1975 were of the order of 10 per cent of the total consumption of energy resources. The United Nations `J' Series of Statistics ex- presses each of the various forms of energy in terms of its coal equivalent in metric tonnes and this basis is followed in this paper. One tonne of black coal (referred to as tce) has been taken as the equivalent of the following. 29 X 109 joules or 27.5 X 106 Btu 0.68 tonnes or 4.8 barrels of crude oil 750 cubic metres or 26.5 X 103 cubic feet of natural gas 1 ò5 to 3.3 tonnes of peat or lignite (world average 2.54; Victorian brown coal 3 0) 8055 kWh (at 3.6 X 106 joules or 3412 Btu per kWh at 100% efficiency) 2660 kWh at 33% efficiency of generation 50 grams of uranium present in natural uranium reactors (see note later under nuclear energy) 0.8 grams natural uranium in breeder reactors Nuclear and hydro electricity are expressed as the coal equivalent required to produce, at 33 per cent efficiency, the same amount of electricity. In other words, electricity produced by these sources is converted to its coal equivalent at the rate of 2660 kWh = 1 tonne coal.

Jan 1, 1978

By M I. Pownceby, M A. Rhamdhani, D M. Fellicia, S Palanisamy, R Z. Mukhlis

The trend of global copper production has prospectively increased over time. Based on typical mined ore grades, 1 t of copper ore generates approximately 6–10 kg of copper, which requires much energy, usually in the form of metallurgical coke. Copper production using carbon as a fuel and reductant contributes up to 0.3 per cent to global greenhouse gas (GHG) emissions. As a result, research into decarbonisation processes applicable to reducing low-grade copper sulfide ores, copper oxides, electronic wastes and other alternative complex Cu-rich materials has increased. Alternative fuels for reducing carbon-rich emissions in pyrometallurgical copper processing include methane, ammonia, biomass, solar and wind power, but in recent times increased focus has been on hydrogen as a potential fuel and reducing agent for materials such as oxidised copper scrap, Cu2O/CuO and Cu-rich slags/e-wastes. From a thermodynamic perspective, hydrogen exhibits a significantly more negative standard Gibbs free energy (ΔG°) than copper oxide making it a suitable reductant and the exothermic thermal effect from reaction between hydrogen and Cu2O/CuO may be used to control process parameters. These characteristics renders hydrogen an ideal gas for reducing copper oxides and copper-containing slags/e-wastes. This review article assesses previous research on utilising hydrogen for producing and refining copper from primary and secondary feed materials.

Jun 19, 2024

By P Dare-Bryan

Many mines have an interest in improving fragmentation at their sublevel caving operations in order to produce better ore recovery, lower dilution and less overbreak. The primary requirement for the extraction phase is to understand and optimise the flow of the fragmented rock in the rings including interactions with the caved material. Rock fragment formation is critically controlled by the blasting phase and can potentially be improved by optimising the dynamic energy distribution throughout the ring through the crafting of explosive charging, priming position and initiation timing. The modelling of fragmentation and damage due to explosive loading of complete rings is inherently and irrevocably a three dimensional problem that is difficult to address. We have therefore initially utilised an analytical code to predict vector peak particle velocities and energies that are restricted to the plane of a ring. Dynamic energy distributions based on common timing and priming practice have been compared with other possibilities using conventional pyrotechnic detonators as well as initiation designs based on accurate electronic detonators. The energy distribution can be quite subtly tailored to increase energy in appropriate regions or to decrease energy in the brow region for example to potentially reduce instability and the probability of misfires. We have also recently developed the capability to efficiently model particle flow using four-sided polygonal elements. Despite the 2D limitations of such a model this results in more realistic fragment interaction and stacking than can be achieved using conventional rigid circular elements. Modelling of a typical sublevel caving ring utilising these elements activated by the correct dynamics offers considerable potential for understanding the influence of the blasting energetics and timing on the complex flow and extraction process.

Jan 1, 2005

By B N. Noller, J C. Ng, S L. Bruce

Mining activities can result in the transfer of harmful elements, including arsenic and lead, into the environment. In Australia, one of the potential future uses of rehabilitated mine land is to stock grazing animals. Elemental uptake is dependent on bioavailable fraction for adsorption upon exposure. Bioavailability data are generally lacking in order to provide realistic health risk assessments relating to harmful elements from mine tailings in Australian conditions. Another key component of risk assessment is the ability to estimate a realistic exposure, or dose rate, of the tailings to the grazing cattle over a set period of time. Hence, we aimed to conduct grazing trials directly on rehabilitated tailings facilities in order to provide valuable in situ information on heavy metal dose rates and associated accumulation. For the laboratory-based evaluation of comparative bioavailability, groups of cattle were fed five days a week on a normal diet spiked with mine tailings or soluble pure salts of target elements (eg sodium arsenate, sodium arsenite and lead acetate) for about eight months. For the field validation, cattle were allowed to graze directly on rehabilitated tailings facilities over a similar length of time. Blood and a biopsy of the muscle and liver were periodically collected to monitor arsenic accumulation. At necropsy, blood, muscle, liver, kidney and other saleable tissues were measured for arsenic concentrations. Although this study was focused on arsenic, lead and other metals were also measured. Predictive models for arsenic and other metals have been established to calculate the maximum grazing duration without the risk of exceeding specific food safety guidelines. The outcome of this study is a predictive model for maximum beneficial use of certain rehabilitated tailings for cattle grazing where grazing activities do not impact on the integrity of the tailings dams.CITATION:Ng, J C, Noller, B N and Bruce, S L, 2014. A predictive model for beneficial use of rehabilitated mine tailings for grazing cattle after mine closure, in Proceedings Life-of-Mine 2014 , pp 563–572 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D Hart

In 1944 some ten or so pieces of legislation impacted on the mining industry. Today in excess of 80 in one way or another apply to the Northern Territory miner. This paper will look at the nature of the legislation that has been introduced and the reasons for its introduction. During the Second World War the mining of resources such as iron, tin etc for the war effort set the platform for the subsequent expansion of the industry in the post-war years. Thereafter, the change in attitudes over the years that have resulted from a more conscious public and more responsible governments and developers associated with the recognition of the legal rights of others and the threat of litigation, will be traced. With a major review of the Northern Territory Mining Act currently in progress, this paper will view ANZMEC's foreshadowed preference for a National Code and the NT's intent of drawing some commonalities with other states of Australia to achieve this aim. Finally, the questions of over-regulation and whether existing legislation is complete will be addressed. From this it is foreshadowed how legislation may develop during the lead into the 21st century.

Jan 1, 1994

By P Collier

From 1972 until 1989 when operations were suspended Bougainville Copper Limited (BCL, owned 53.58 per cent by Rio Tinto Limited) operated a large open pit mine and processing facility at Panguna on Bougainville Island, Papua New Guinea producing copper concentrate containing significant quantities of gold and silver.BCL has a stated vision of recommencing operations at Panguna. In 2008, Rio Tinto, on behalf of BCL, conducted a multi-disciplinary study to assess the technical and financial viability of redeveloping the Panguna operation. One of the key outputs of the study was a Joint Ore Reserves Committee (JORC) Code compliant mineral resource statement based on the existing block model and fundamental data, archived since mine closure. Historical data (including the resource block model and drill hole data) was recovered from computer archives by a former Panguna mine employee familiar with the various obsolete data formats, thus maintaining an unbroken chain of custody of the data by Rio Tinto since operations were suspended. No additional data were collected as part of this study.The extensive data and documentation archive facilitated a sufficiently detailed evaluation of the fundamental data and model to support an updated resource statement. Table 1 of the JORC Code was used to guide the model validation process.Reconciliation of blasthole and metallurgical plant data with the reserve model, indicated that the copper and gold drill hole composite database was significantly biased towards underestimation in several key domains due to a combination of the following: mineralisation loss during core loss, core loss (minor), vertical drill holes failing to intersect sufficient subvertical mineralised fractures and veins, drill hole spacing too wide, and variable diamond drill hole core size. The resource model evaluation was based on three material types (all previously mined at Panguna), that were defined based on cut-off grade and rock type parameters: direct feed ore – material for delivery directly to the plant, preconcentration and screening ore – subeconomic material beneficiated to produce fines of economic grade, and waste. Three pit shells and designs were generated based on three separate sets of economic parameters. These economic parameters were also used to assign material types to the block model. The three resulting models were then evaluated against the corresponding pit shells.Classification of the resource was approached conservatively due to the inherent bias in the drill hole data. Consequently only Indicated and Inferred resources were tabulated.The study highlighted the importance of maintaining detailed documentation pertaining to resource estimates and operational history, particularly reconciliation, and the value that can be added by a simple, low-cost data compilation exercise.

Aug 22, 2011

In classical drill and blast underground mining methods, especially narrow vein operations economic quantities of broken ore can be left behind following normal mucking operations on the stope floors. The ore left behind can have significant economic value and if not collected can be lost forever. This paper reviews techniques for cleaning this material from stopes that have been used in the past and reviews possible modern techniques that can be applied to ensure this valuable material is removed from the stopes.

Aug 1, 2010

By M R. Asef

Although generation of environmentally harmful hydrogen sulfide is considered to be related to sour gas fields, sweet gas reservoirs and waste fluids, travertine springs and geothermal fields may also produce acid gas (H2S and CO2) under certain conditions. The potential parameters influencing such a possibility need to be fully investigated to evaluate the extent of the consequences and predict hydrogen sulfide generation accordingly. Reports on hydrogen sulfide production at different regions and fields were gathered worldwide for the cases when some of them did not have such a problem previously. In order to inspect different aspects of these case studies, some other regions with no hydrogen sulfide content were selected as control. In all cases water samples were taken carefully for chemical analysis in the laboratory. Besides, mineral compositions were characterised in some cases for better evaluation. In order to give a thorough prospect of hydrogen sulfide production, a geochemical model was prepared. In situ engineering geological conditions, especially pressure and temperature, were assigned in the model to investigate the possibility of H2S generation using PHREEQC software. The results of modelling revealed that although many similarities existed between mineral compositions of the cases, certain formations were particularly prone to hydrogen sulfide generation. For better evaluation, important exchangeable cation ratios such as potassium/sodium, calcium/magnesium and ion proportions like sulfate and chloride were calculated as trends of the formations. As expected, the model could successfully monitor a higher ratio of SO42- and Cl- in potential H2S generator formations. Wide variation in percentage of HCO3- was considered as a secondary observatory parameter for better estimation. In addition, it was noticed that higher anion content created an environment ready to absorb any cations and this makes H2S generation easier. Finally, using correlations between predictors and estimators for low depth and deep samples defined the degree of effectiveness for every sample.

Sep 26, 2011