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The paper outlines the philosophies and the methods applied to resource estimation by North Flinders Mines Limited at The Granites. These are based on recognition of the prime importance of quality data, accurate geological perception of the deposit, and the judgement of the estimator. With reference to one particular deposit, East Bullakitchie, the series of resources statements published over a 5 year period is compared with the corresponding history of discovery and development. The comparison Illustrates:

Jan 1, 1990

By E Villaescusa, C Drover, I Onederra

Development face destress blasting is a construction technique in deep mining, which aims to prevent, reduce the frequency, or manipulate the timing of violent, stress-driven rock mass instability at the face. This paper presents a destress blasting design concept that was optimised for the specific rock mass conditions of a deep mine using the Hybrid Stress Blasting Model (HSBM) software. The design was then implemented in an area of the mine where stress-driven instability of the face regularly occurred during development. An adjacent tunnel was constructed in parallel without destressing, within the same rock mass conditions, as a control. The rock mass response to each excavation was quantitatively compared using high-resolution local seismic monitoring. Visual observations of the fractures created by destress blasting were also made. The analysis indicated that destressing reduced both seismicity and the rock mass stiffness ahead of the face. This was inferred from the spatial broadening of the development seismogenic zone and the typically significant reduction in the spatial density of seismic events. Seismic source mechanism analysis also indicated that destress blasting generated a much wider variety of failure modes than conventional blasting. Most seismic source mechanisms following destressing were associated with natural joint structures. A relatively small portion were consistent with newly created blast-induced fractures. The greater diversity of rock mass failure modes associated with destressing implied a lower potential for stain-energy accumulation within the rock mass at the face, and thus a lower risk of hazardous instability. Observations of visible rock fracturing indicated that the major principal stress influenced the damage intensity on natural geological structures within the destressed zone, and that numerical predictions of radial fracturing limits made by HSBM analysis were realistic representations of the real blasting performance.

Nov 29, 2022

By G McCullough, B Mutsaers, J Jessop

"*This is an abstract only* Geometallurgical initiatives have demonstrated considerable value to operations that have trialled them. However, it is extremely difficult for these initiatives to become properly embedded into the operations and for that value to be realised on an ongoing basis.This paper will explore some of the historical reasons why this is the case. Some of these reasons include the limited tools available to manage an integrated operation. These, in turn, have resulted from poor communications infrastructure, inadequate sensor capability and the way technical mining software has evolved over the last 30 years.This paper will then investigate how the evolution of technology in recent years can help overcome these constraints and compare progress with similar industries.CITATION:McCullough, G, Mutsaers, B and Jessop, J, 2013. Obstacles to embedding geometallurgy decision-making into operations and how to increase maturity of this critical capability, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 139-140 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By P J. Bangerter, J Pan

Optimising for Net Present Value (NPV) with a strategic optimiser such as COMET, Prober-E, Blaser or Minemax has hitherto lacked a dynamic method for analysing the so-called third-order outcomes (such as Carbon emissions) of optimisation within life-of-mine planning. Optimisation, per se, has natural effects on carbon emissions in a life-of-mine plan. Contemporary strategic planning employs a mathematical optimiser to make sense of non-linear data (ie a block model) and produces a best-NPV optimised mining schedule, within a set of constraints. The very act of optimisation influences emissions, and in a dynamic way.

Aug 2, 2023

By J Finlay, P Betts, D Milton, H Williams

The aim of this paper is to present an innovative method to help delineate potential target volumes for haematite-goethite mineralisation as opposed to more magnetic ores. This is achieved through interpretation and modelling (2.5D and 3D inversions) of ground magnetics and gravity surveys over the Koolanooka South prospect in Western Australia. The targets are assumed to be dense and weakly magnetic and hosted within banded iron formation (BIF) horizons. Geophysical interpretation (2D map) was performed using a variety of processed magnetic and gravity images (Betts et al, 2007) to determine the distribution of lithologies, to understand the structural architecture and to map out any anomalous areas of excess density (possibly indicating goethite alteration). The created geological map is used to build geological cross-sections (geometrically consistent) that were modelled (in 2.5 D) against both potential field datasets. The crosssections are consequently used as the framework to build a 3D geological model. The model defines 3D volumes of rocks including several BIF horizons. The distribution of densities and magnetic susceptibilities of the BIFs is inverted within the GOCAD«-VPmg environment to reduce the misfit between the response of the model and the observed gravity and magnetics. By combining the results of both petrophysical property distribution it is possible to map out (using classical GIS type queries in 3D) volumes of higher density and lower magnetic susceptibility.

Jan 1, 2009

By K Brand, M J. Ind, M Rynhoud

Water management at a tailings storage facility (TSF) presents one of the major risks to the safe performance of the facility. International and domestic dam safety guidelines assess a dam’s hazard category based on the consequences of a dam failure and the subsequent downstream damage to the environment and communities.Often a rigorous risk assessment is undertaken during the design stages to identify and control hazards associated with water management through life-of-mine (LOM) phases. However, as experienced during the recent downturn in commodity prices, early closure of a mine can occur rapidly and unexpectedly. Although guidelines such as the Australian National Committee on Large Dams Incorporated (ANCOLD) recommend that one of the key objectives of integrated TSF planning is to ‘plan all phases of a tailing dam’s life to ensure adequate storage capacity including early closure ’ (Australian National Committee on Large Dams Incorporated (ANCOLD), 2012) this is often overlooked by owners who are focused on fulfilling the mine’s potential and early closure is not on their radar.CITATION:Ind, M J, Rynhoud, M and Brand, K, 2016. Life-of-mine spillway strategy – managing risk associated with surface water at a tailings storage facility, in Proceedings Life-of-Mine 2016 Conference, pp 209–211 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Wright S

Single pellets of mixed lead-zinc concentrate containing up to 20 % lead were roasted in the temperature range of 800-1100¦C. Variables studied included pellet size (from 9-8 to 3-2 mm diameter), gas flowrate past the pellet (from 0.05 to 5 ms t), composition of the atmosphere and the effect of additives such as zinc oxide and silica. After defined periods of time, the pellets were removed from the furnace, quenched and submitted for chemical, XRD, SEM and microprobe analysis. The oxidation of the zinc sulphide followed a shrinking core model. Temperature measurements showed that very high pellet temperatures were experienced at the start of an experiment but after 5-10 minutes these approached a constant temperature. The lead loss from the pellets was then constant with time. Thermodynamics predicted the presence of two bands of lead material in the reacted layer of the pellet. These were found in practice. The lead loss from the pellet occurred from the outer oxysulphate layer via the vaporization of lead oxide polymers. The vapour pressure of PbO, and the loss of lead, was dependent on temperature and bulk gas concentrations of SO2 and 02. At 1100¦C the addition of silica greatly reduced the loss of lead from the pellet. Physical factors such as pellet diameter and gas flowrate past the pellet affected the particle dynamics. These results were found to vary in accordance with the predictions of the Froessling equation.

Jan 1, 1989

By A Maier, M Goldner, C Gimber

Given the ongoing global crises of climate change and nature loss, with the World Economic Forum (WEF) identifying them as the top risks to global economies in terms of both likelihood and impact in the coming ten years (WEF, 2022), there is increasing, pressing demand for companies to demonstrate they understand their climate and nature related risks and look toward contributing genuine beneficial environmental outcomes. Within the mining industry, mine closure is the obvious field in which climate and nature positive strategy can be linked with operations. To do so, there is a need to challenge long-held assumptions around closure in the mining and regulatory context; particularly, to shift the focus from closing individual mines to considering regional opportunity generation and value creation.

Aug 2, 2023

By Perring CS, Barnes SJ

The nickel exploration boom of the late-1960s and early-1970s led to the discovery of numerous komatiite-hosted nickel sulphide deposits, associated with variably serpentinised bodies of olivine-rich cumulates. Subsequent research has shown the importance of volcanological processes to understanding the genesis of these deposits. Crucial developments have come through consideration of the fluid dynamics of magmas and magma-crystal mixtures, through observation of the dynamics and geometry of modern day basaltic lava flows, through application of theory and experimentation on the kinetics of crystal growth from magmas, and most importantly from extensive detailed field mapping of komatiitic sequences in the Yilgarn Block and elsewhere. From these studies has emerged a new integrated view of the volcanological setting of komatiite-hosted deposits, and a recognition that a complete continuum of deposit types exists. Nevertheless, komatiite associated magmatic nickel deposits generally fall into two overall types based on the nature of the sulphide ore. In the first type the bulk of the ore is either massive Fe-Ni-Cu sulphide or a variable mixture of massive sulphide and an ore characterised by olivine crystals in a continuous matrix of sulphide occupying between 30 and 75 per cent by volume of the rock (called Matrix Ore). Nickel grades of massive sulphide ore range from 2 - 20 wt% and those of the matrix ore generally fall in the range 1 - 5 wt% (average 2.5 wt%) Ni/Cu ratios of the sulphide fraction are generally >10.

Jan 1, 1996

By T R. Stacey

South Africa has a long history of rockbursts, some 100 years. During this time much research and many developments have taken place in the country to limit the occurrence of rockbursts, and to mitigate their effects. In this paper I shall present a personal view of what I consider to be important achievements, and contributions made. Some of these are: planning of stope layouts, and the use of strike barrier pillars; recognition of energy as a key factor, the use of the energy release rate ERR as a layout planning criterion, and development of MINSIM for calculation of ERR and stope planning; sequential grid stope layouts; use of backfill for stope support; and, development yielding support elements, and dynamic testing of stope and tunnel supports. The record shows the establishment of a rock engineering research powerhouse over a 40 to 50 year period and, unfortunately, the complete breakdown of this capability in the subsequent 10 years. CITATION:Stacey, T R, 2018. A personal review of South African rockburst research, experience and lessons learnt, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 5–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By G K. N Subasinghe

"In the design and operation of mineral processing plants, knowledge of the variability of ore properties and that of the expected metallurgical performance within the orebody is of great importance in order to avoid both production constraints due to inadequate design and less than expected metallurgical performance during operation. Of the many properties that determine the performance of downstream separation processes, such as flotation, gravity separation and leaching etc the liberation characteristics are of primary importance.Current methods of evaluating liberation characteristics of ores such as the use of Mineral Liberation Analyzer (MLA) and QEMSCAN techniques are expensive and suffer from the drawback that these tests are performed on comminuted particles at a given grind size and/or samples of product streams. This problem could be overcome by developing predictive models of liberation that can predict the grade distribution of comminuted products at any grind size based on texture of the parent rock. This paper discusses a procedure that has been developed to predict liberation using information obtained from a sample of the parent rock such as drill core, based on Barbery’s liberation models. The required characteristic statistical functions have been evaluated from image analysis techniques using scanning electron microscope (SEM) images of the parent rock and narrowly sized comminuted particles. Such information can then be used in a predictive model to predict or explain the variability of metallurgical performance at various grind sizes used in future operating plants. The model will predict not only the valuable mineral liberation but also gangue liberation, which will be useful to those who are looking to remove liberated gangue from comminution circuits.CITATION:Subasinghe, G K N, and Dunne, R, 2016. Predictive Model of Mineral Liberation for Geometallurgical Applications, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 347–350 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By G V. R Goodman, G J. Chekan, J M. Listak

The extraction and transport of coal from underground coal mines can result in significant liberation of coal and/or silica dust into the mine atmosphere. Mine operators have long used ventilating air as a primary means of diluting generated dust, removing dust from the working faces and preventing dust from reaching the minersÆ working environment. As production levels have increased, mine operators continue to be challenged in maintaining dust concentrations below compliance levels. The need for maximising the effectiveness of available ventilating air in conjunction with other effective controls, such as water sprays and dust collectors, continues to be critical to the long-term health of mine workers. The National Institute for Occupational Safety and Health (NIOSH) has conducted full-scale laboratory and mine-site research to evaluate improved application of dust controls for both longwall and continuous mining methods. A summary of recent research results and recommended practices will be provided.

Jan 1, 2005

By C Slaughter, J C. Tien

Commonly held ideas about effective training have long emphasised the importance of realism. Realistic training builds better experience among the trainees and a better perspective on the training material, making training more effective. While great strides have been made in this realm for mine safety and mine rescue training there are still areas that can be improved. One possible area is the expanded use of a mine fire simulation program where the migration of gases and smoke can be realistically displayed in an emergency, and outcomes varied as different conditions are being simulated. The use of mine fire simulation software potentially allows for the creation of more realistic scenarios in that smoke advance rates can be measured and recreated in evacuation scenarios, or that gas readings in mine rescue training can be dynamically and realistically changed to show the effect that time has on the fire scenario.CITATION:Slaughter, C and Tien, J C, 2015. The potential use of mine fire simulation software as an enhancement for mine safety and mine rescue training, in Proceedings The Australian Mine Ventilation Conference, pp 285–290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By J-P Franzidis, E V. Manl, K Runge

Over recent years a number of techniques have been developed as part of the Australian Minerals Industries Research Association (AMIRA) P9 project to represent mathematically or measure directly subprocesses occurring in flotation cells. These include the determination of a:machine parameter (bubble surface area flux, Sb); froth parameter (froth recovery, Rf); entrainment and drainage parameters; and ore floatability parameter (Pi). A cost-effective methodology was developed for using these techniques to derive models of flotation circuits. This methodology was applied to derive a model of the flotation circuit at the Western Mining Corporation (WMC) Ltd Mt Keith Nickel Concentrator. The model was used to simulate a number of minor circuit flowsheet changes, the results of which are discussed in this paper. One year later, a second study of this plant was conducted. In this second study, data were collected while operating the plant in the flowsheet configurations that were simulated from the model developed from the first study. The results obtained from the second study showed reasonable agreement with the trends predicted from the first study model; discrepancies can be explained in terms of the model assumptions. This suggests that this simple circuit modelling methodology can be useful in assisting plant engineers to optimise flotation circuits.

Jan 1, 2000

The issue of fine coal and tailings dewatering has become of increasing concern to many coal preparation operators, both in Australia and overseas due to a variety of factors. Increasing mechanisation and mining of thinner seams over the past decades has resulted in an increasing amount of fines generation while increasing international trade in coal and tighter environmental constraints on tailings disposal have resulted in the production of these same fines to be an increasing problem. However, technology to date has not always been able to supply a cost-effective solution to the handling of these fines in an efficient and environmentally benign manner. This paper will review the key issues associated with the dewatering of fine coal and tailings, will describe the major current practices and constraints, and finally will indicate alternative technologies that may have to be considered in the near future. For the purpose of this paper, "fine" coal is described as that material less than 0.5 mm in diameter (as this is the most common cutpoint between various plant circuits in Australian practice), although the technological constraints are very much dependent upon the fraction less than 45 micron. The amount of minus 0.5 mm material fed to plants varies, depending upon the type of coal and mining operation, but in Australia may range from less than ten per cent to greater than 30 per cent of the feed in higher rank coals.

Jan 1, 1991

By D Gerrard, J Begelhole, J Gerber

The Iron Magnet deposit has been mined since 2007 when Arrium (then OneSteel) commissioned the magnetite concentrator to supply feed to the pelletising plant in Whyalla. The concentrate quality requirement for the customer required consistent product with minimal variability. In the early stages of operation, it was identified that the feed variability introduced significant changes in the concentrate quality, which was outside the acceptable customer limits.In 2011, a geometallurgical regression model was developed that allowed for the estimation of concentrate quality produced from the feed material. This was based on a laboratory-scale Davis Tube Recovery (DTR) test performed on the feed material. The objective of the project was to characterise the raw ore in the pit to allow for blending prior to crushing. By blending the feed to the concentrator, minimal concentrate quality variation within the plant was achieved. The orebody was divided into geometallurgical classes, called ore types, based on the mineral texture and magnetic mass recovery. Each geometallurgical class consisted of material with similar metallurgical performances. For each individual blast pattern, the ore was grouped into the geometallurgical classes and a composite sample was created. The composite sample was put through the laboratory-scale DTR test and the results were used to estimate the metallurgical performance of the material.The characterisation process and feed pile build methodology was applied in early 2013 and went through an optimisation and streamlining phase. Since the implementation of the geometallurgical characterisation process, the plant has seen a significant reduction in concentrate variability and measurable throughput gains. The characterisation process has also increased the amount of material that is now classified as ore.CITATION:Gerber, J, Gerrard, D and Begelhole, J, 2015. Geometallurgy of the South Middleback Ranges magnetite deposit – predicting plant performance from the pit, in Proceedings Iron Ore 2015, pp 555–560 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By R Valenta, A Littleboy

Geological heterogeneity is one dimension of complexity in mining. Significant effort is put into developing an understanding of this complexity so it can be used in resource estimation, mine planning and economic modelling. However, over the decadal lifespan of a mining venture, many other dimensions add to the complexity of a mining operation. These include: technological evolution, market fluctuations; investor confidence; social norms; local expectations; and ecosystem functionality. As with geology, these factors are all heterogeneous, uncertain, time varying and represented through sparse and incomplete datasets. Recent work (Valenta et al) is beginning to show us how these risks correlate in different global settings. By analysing data relating to known, but as yet undeveloped copper deposits, this work (the complex ore body database) is demonstrating that it is the combination of issues (both price sensitive and non price-sensitive) that determine the viability of a deposit for extraction in the 21st century.CITATION: Littleboy, A, Plint, N and Valenta, R, 2018. Mining as a complex system: do we need a new model?, in Proceedings Complex Orebodies Conference 2018, pp 41–43 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

Mond gas-producer tar, and, in fact, all tars obtained from the retorting of coal where steam and air are admitted to the retort, are of entirely different chemical composition to the ordinary coal tar made in the gas or coke works. These tars contain none of, the aromatic hydrocarbons - benzene, toluene, naphthalene, and anthracene, sought after by the ordinary coal-tar refiner.The distillation of Mond tar shows it to consist of phenols of high molecular weight, unsaturated hydrocarbons of high gravity and low viscosity, paraffin wax, and resinous substances of whose composition little is known.The physical properties of Mond producer tar are also peculiar. It has a "short," granular texture when cold, which might be likened to candied honey. It "dries" (hardens) when exposed in thin layers to the air, and, for a coal tar, it cannot be considered sticky. This latterò property, combined with the short texture, prevents its being used successfully for road-making or macadamizing.The drying properties and the paraffin wax contained in: this tar cause it to hold up large percentages of water, probably in the form of emulsion. When containing as much as 10% to 15% moisture it appears to be quite dry.

Jan 1, 1918

By K C. Corin, C T. O’Connor

In recent years it has been shown that the concept of using partial molar excess Gibbs energy (G̅ex) to explain the behaviour of collectors in the recovery of minerals can be usefully applied to explain flotation performance. Fundamentally this is because hydrophobicity of a mineral particle on which a collector is adsorbed may be strongly related to the fact that the alkyl chain associated with the collector behaves in the same way as any hydrocarbon would in an aqueous medium. This hydrocarbon-water system represents a classical non-ideal mixture, and such mixtures are quantified thermodynamically by determining the activity coefficient of the hydrocarbon moiety of the collector and hence its G̅ex in the mixture. It has been shown that G̅ex is a more rigorous indicator of the contributions of various alkyl groups of a collector than HLB (Corin and O’Connor, 2014) and was also able to explain aspects of froth behaviour (Harris and O’Connor, 2017) and hydrophobicity (O’Connor, 2021). The present paper is aimed at extending the above concepts in two different ways. Firstly, a study is undertaken of a range of results previously reported in which various reagents containing different alkyl groups were analysed in terms of their effect on contact angle and their performance as flotation reagents in terms of recovery. These results sustain the previous observations that there is a robust positive relationship between hydrophobicity as indicated by flotation recovery and contact angle and G̅ex of the alkyl group associated with the collector. Secondly, on the basis of the observation that increases in G̅ex are indicative of increases in the hydrophobicity of the mineral particle-collector aggregate, a study was undertaken to examine the effect of ions typical of electrolytes in water as well as the effect of the presence of alcohols and of pH on G̅ex of the collector alkyl group. In the former two instances the absence of any correlation between G̅ex and recoveries supported the proposition of the respective authors of these studies that the major effect of these electrolytes and added alcohols may be on particle–bubble attachment rather than on the hydrophobicity of the mineral/collector in the aqueous system. On the other hand, the effect of pH on G̅ex correlated reasonably well with changes reported in the literature on the effect of pH on recovery and contact angle.

Aug 24, 2022

S. A. Tomich (Consulting Geologist, Perth) : I would like to commend Mr. Haycraft on his presentation on the economic geology of the North End of Kalgoorlie. This is an intriguing area which is in the Kalgoorlie field but not of it, inasmuch as it is separated spatially from the main Golden Mile by the Golden Pike Fault. Mr. Haycraft has stressed the differences-the mineralogical and structural differences of economic significance between the two areas.I would like to ask whether he is satisfied that the lithological sequence in the North End is the duplicate of that in the main Golden Mile area irrespective of the postulated effects of erosion, and more specifically whether there is any chance that the quartz-dolerite-greenstone of the North End may be in any way dissimilar from the quartz-dolerite-greenstoneof the Golden Mile which is tellurude bearing.J. A. Haycraft: In relating the quartz-dolerite in the Hannan's North-Mount Charlotte area back to the Golden Mile, we find some quite close similarities. Although the rocks are similar they are not necessarily one and the same.At Mount Charlotte we have three varieties of dolerite- a coarse-grained gabbroic dolerite on the eastern side of the orebody, the host rock medium grained and on the western side, a fine grained dolerite. Further west we have an amphibolitic variety of quartz dolerite.Recent drilling south of the Golden Pike fault on the Enterprise No. 20 level had indicated a remarkably similar sequence of rocks. We drilled west through a wide section of medium grained rocks into a fine grained rock and then into amphibolitic quartz dolerite before intersecting the Golden Pike fault. Williamstown dolerite was located west...

Jan 1, 1965