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By Wang SS, Frattaroll DR

In the development of novel sulfide collectors, especially for the low-lime and acid circuits, flotation of chalcopyrite, chalcocite, covellite and pyrite was studied with both new and commercially available S- containing collectors. The natural float- ability of sulfides, water quality, and redox potentials - all of which were considered im- portant in assessing collector strength and selectivity - were also investigated. Chalcopyrite exhibited the highest natural floatability. The response to most collectors, however, was chalcocite > covellite > chalcopyrite > pyrite. Water quality had a very significant effect on both natural and collector-aided floatability. De- ionized water and tap water had a flotation suppression effect compared with doubly- distilled water. Flotation results with single minerals are correlated with those for copper and pyrite from natural ores. Several novel collectors have now been developed for sulfide flotation in acid, neutral or mildly alkaline circuits. The results for four of these collectors, which have shown promise in commercial applications, are discussed in this paper.

Jan 1, 1986

By Just GD, Gillies ADS

There is an increasing need for reliable and comparable coal resource data and it is necessary to standardize the traditional classification procedures by quantifying the three basic evaluation criteria of economic feasibility, geologic assurance and recovery. For well documented deposits, geostatistical methods can consider- ably improve classification quality. A geostatistically based algorithm for classifying coal resources within the current Queensland and New South Wales codes has been developed. Application of the method in classifying resources from a number of seams exhibiting different structural characteristics is assessed. The method is found to give classification results which closely reflect the error associated with an estimate of resource quantities based on current sampling densi- ties. It requires a careful geostatistical analysis with emphasis on geological awareness. Resource category restrictions must be arbi- trarily assigned and remain constant for all deposits being compared. Engineering judgement is needed and interpretation may be required with isolated and peripheral blocks.

Jan 1, 1987

The mechanism of caving is of interest to the mining engineer only in areas where he is directly concerned. One area is surface subsidence which is outside the scope of this paper. Another area is at the face where coal is being extracted and where control of caving is of vital importance. Coal mining systems have been developed with many considerations in mind, but in this list of considerations, strata control has seldom been given much importance. Research is in progress in Australia to endeavour to determine an optimum sequence for coal extraction underground. As information becomes avail- able from this work it is hoped that appropriate methods of controlling caving in various strata conditions will be devised. When this is done, equipment may be introduced to permit the mining operation to proceed under optimum conditions for strata control, rather than devising a mining procedure to suit the equipment available and methods developed for other reasons.

Jan 1, 1974

By Munive L

As a result of commissioning No.5 B F, 2670m3 inner volume, in March 1972, the largest B F in Australia; new expertise in maintenance, furnace operating practices and design have been obtained. This experience has also been extended to the other furnaces. A series of operating problems were con- fronted; all parts of the furnace, including the hearth side walls and bottom,were adversely affected. In December 1977, serious hearth wall wear was detected at No.5 B F, and a potential hearth breakout was averted. Hearth wear in No.4 B F was discovered in March 1979, and emer- gency underhearth cooling was installed to reverse an extremely advanced hearth bottom erosion. Hearth behaviour of No.5 B F oampaign 1972-1978 and`No.4 B F campaign commencing 1972, has been studied and discussions on the causes, effects and measures undertaken to protect the hearths are presented in this paper.

Jan 1, 1981

L&M have been involved on the Shotover since 1980 when we joined Jack and Barney Ryan, who had started in 1972 with gold at $45 per ounce after a successful career as roading and demolition contractors in Christchurch. The first 85 tonne plant was a typical NZ trammel-riffle table plant with an armour plated hull for surviving Shotover floods, and was fed by a 53 tonne UH20 excavator. All this gear had to be carted in over the Skippers road on a small truck or sledge for the heavy loads. This operation was successful and generated the cash flow to sample the lower section of river and plan a second plant. To reduce fine gold losses this was planned to be a jig recovery plant and also included a vibrating screen which saved space and weight over a trammel. There are five flowlines of primary jigs and one secondary, followed by two Knudsen bowls for cleanup.

Jan 1, 1985

A variety of environmental financial assurance instruments are in use across the globe. This paper reviews some of the more common forms currently used in New Zealand, Canada, USA and Australia. In order to be effective, the form of assurance instrument selected needs to be aligned with a countryÆs specific environmental objectives, geography and political climates and also allow for a healthy investment climate. Industry and Government both have a strong interest in ensuring financial assurance criteria meet these objectives.   Recently Golder Associates have been involved in financial assurance assessments for various mining and quarrying companies across the South Island. Multiple stakeholders and regulatory agencies can make the setting of effective and fair financial assurance criteria a complex exercise for both regulatory agencies and industry.  The author relates experience gained in assessing financial assurance under current New Zealand legislation (RMA, 1991), effectively dealing with issues such as ôdouble bondingö and overviews potential approaches to dealing with transitional issues for historic and existing operating mine sites.

Jan 1, 2006

It is difficult to evaluate exploration properties in a manner that is transparent, repeatable and easily re-calculated to cater for different geological interpretations, but the risk-based assessment methodology, the Geological Risk Method, developed and described by Lord et al (2001) attempts to satisfy all these criteria. This paper examines a case study example based on valuations of exploration projects conducted by SRK Consulting using this methodology, and describes some of the advantages and limitations of the method.

Jan 1, 2007

By K Knorr

Desktop X-ray powder diffraction using a D2 PHASER equipped with fast linear detector was performed on several iron ore and mill scale samples. Data were analysed using cluster analysis and Rietveld quantitative phase analysis. The quantitative mineralogy of both materials could be established. Thus the input is provided for understanding the energy consumption and the CO2 emission during iron production. Furthermore, tabletop XRD allows to distinguish iron ore from mill scales and to quantify their mixtures.

Jul 11, 2011

By J Addai-Mensah, M Adam, W Skinner, J Begelhole, K Quast

Granulation of iron ore fines into robust granules is critical to successful sintering and blast furnace operations in iron and steelmaking. Iron and steelmakers desire iron ore granules with high strength, uniform size distribution and low fuel consumption to enhance efficient sintering operation. Unlike hematite ore, magnetite concentrates do not granulate easily at low binder dosage to yield coarser granules due to the absence of nucleus particles. This motivates the present study to harness the complementary properties of hematite ore to enhance granulation of magnetite concentrates via blending. The current state-of-the-art in hematite and magnetite blend granulation is reviewed, along with granule property limitations. Preliminary experimental work on granulation of hematite and magnetite blends as a precursor to sintering is reported.CITATION:Adam, M, Addai-Mensah, J, Begelhole, J, Quast, K and Skinner, W, 2017. Enhancing magnetite concentrate granulation by blending with hematite ore, in Proceedings Iron Ore 2017, pp 17–24 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By A Turns

In a survey conducted by symplexi with underground miners in Australia; 78 per cent of participants believed that ‘safety’ is all about people. If ‘safety’ is about people, then is the mining industry focusing on the wrong thing? It would be fair to say that the mining industry is heavily systems focused. Companies develop a safety management system and use this to show regulators that they comply with legislation – however, that is only half of the picture.

May 5, 2022

By S Hapugoda, J R. Manuel, M J. Peterson

Microindentation testing using the square–pyramid–shaped Vickers indenter is a well-established technique to determine the microhardness of minerals and materials. However there is a paucity of published microhardness data from Fe ore samples. It is acknowledged that an iron ore’s particle mineralogy and texture is critical to its processing properties, and it is therefore considered that the microhardness of different mineralogical/textural types may also relate to these properties. Mineral microhardness potentially provides inputs to the modelling of breakage characteristics during comminution, as well as the relationship between mineral chemistry and microhardness, and mineral microporosity and microhardness. Microhardness can be determined as single crystal microhardness, for more coarsely microcrystalline samples, or as ‘aggregate microhardness’ for cryptocrystalline or finely microcrystalline samples.Variations in the texture and mineral chemistry of common Fe ore minerals (eg martite and microplaty hematite, ochreous and vitreous goethite etc) are well established and this study provides microhardness data on different textural forms of Fe (oxyhydr)oxides from a variety of different Fe ore deposits. The data indicated that in general, the mineral grain size, microporosity and texture were the main influences on Fe (oxyhydr)oxide microhardness. There were no apparent systematic variations between microhardness and minor element mineral chemistry, with the possible exception of Al content in goethite (for goethites with Al content >0.5 wt per cent), and for goethite total element contents >90 wt per cent (determined by electron probe microanalysis, EPMA). Higher Al concentrations and lower total element concentrations in goethite EPMA analyses correlated with lower goethite microhardness. Microporosity and grain size were more important than texture to hematite microhardness. Different textural forms of dense hematite (eg martite, recrystallised interlocking hematite and specular hematite) with similar grain size exhibited comparable microhardness. Microhardness values for hematite and hydrohematite with little or no evident microporosity were also similar, whereas more porous forms of martite, microplaty hematite or hydrohematite exhibited lower microhardness.CITATION:Peterson, M J, Manuel, J R and Hapugoda, S, 2017. Microhardness testing of hematite-goethite Fe ores – implications for their textural characterisation and geometallurgy, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Stope back conditions in the cut-and-fill stopes at New Broken Hill Consolidated Limited often deteriorate to such an extent that, because conventional rockbolts are not able to maintain safe working conditions, square-set timber is installed. An attempt to eliminate this costly procedure has involved the use of long grouted rockbolts using high tensile prestressing wire. These bolts were developed in conjunction with the prestressing engineers of BBR (Aust.). This form of support has improved the back conditions, maintained safe working conditions, and delayed the introduction of timber in a number of stopes.Production from these stopes has been maintained at its previous level (at a rate approximately double that of a comparable timber stope).

Jan 1, 1974

Development of New Comminution Testing Methodologies for Geometallurgical Mapping of Ore Hardness and Throughput The emerging discipline of 'geometallurgy' is becoming increasingly recognised as a discrete and high-value activity that reflects an ongoing trend towards more effective mine site integration and optimisation. Constrained sampling that reflects and defines inherent ore body variability is a key geometallurgical requirement. This requires use of larger numbers of low-cost physical testing which can be applied to small sample volumes suitable for defining natural variability. The AMIRA P843 'GeMIII' project (Geometallurgical Mapping and Mine Modelling) is a major industry-supported research initiative designed to develop new tools, methods and protocols to support geometallurgical integration. As part of this integrated research a new more rapid low-cost comminution test (GeM Comminution index) has been developed which can be employed as a front line tool for geometallurgical mapping purposes and predictive throughput modelling. The test has been designed to be inserted into routine assay sample preparation and is based on constrained jaw crushing protocols linked to analysis of resultant size distributions. Extensive validation and modelling has shown the GeM Comminution Index (Ci) is correlated with the Drop Weight index A*b and Bond Mill Work Index (BMWi). Large scale trials have been conducted within a commercial assay laboratory to demonstrate and optimise incorporation of the Ci test into routine sample preparation protocols. While Ci based estimates of A*b and BMWi are not as precise compared to larger volume more expensive test-work, the ability to undertake large numbers of tests typically in a systematic down-hole manner, provides a high level of data support through adjacency. A Ci based approach is highly suitable for variability mapping, domaining and selecting large composite samples for more precise testing. Within the context of the AMIRA P843 project this forms part of an integrated work flow designed to support geometallurgical integration. The development of a comminution test linked to routine assay sample preparation represents significant value adding to a process that in most cases is already going to be carried out. This paper introduces the Ci test concept and application to geometallurgical testing for throughput modelling

Sep 13, 2010

By Gillies A. D S, Lee A. H

Water is an integral component of a mining operation. To-date water management has received a low profile in the overall management of mining operations. To cost effectively meet the requirements of government environmental legislation the man

Jan 1, 1994

By Corbett GJ

Epithermal gold-silver deposits occur in young volcanic terrains where post-mineral cover commonly impedes the search for mineralisation. At the Togi Project in Honshu, Japan, a complex mineralised system is largely covered by post mineral volcaniclastics. A combination of high resolution electrical resistivity surveying and detailed airphoto interpretation has, with close geological control, enabled synthesis of structural and alteration characteristics of the Togi geothermal system, in turn permitting ranking of the prospects for drill testing.

Jan 1, 1990

By O S. Maluleke

In some deposits valuable heavy mineral quality is poor due to increased mineral surface coatings from higher slimes and more competent sand orebodies. Mineral surface coating can include silica or aluminium rich clay minerals and iron based minerals that render the final product quality off-specification, in this case specifically ilmenite and zircon. Conventional physical beneficiation processes such as magnetic separation, electrostatic separation and gravity separation are not able to remove these surface coatings. Surface dependent separation techniques such as electrostatic separators are affected by these coatings which hinders the rejection of non-valuable mineral from product. Attrition scrubbing is the most commonly used technique to reduce surface coatings, using mechanically induced particle to particle interaction, abrasion and shearing.In many cases it is a challenge to measure the surface removal efficiency of these scrubbing units. Elemental analysis techniques (ie X-ray flourescence) (XRF) in a multi mineral environment are unable to measure surface impurity reduction with enough precision. Mineralogical analysis (in this case Qemscan®) has constraints in terms of sample preparation with highly coated particles being plucked out during block polishing. This paper suggests a combination of laboratory separation techniques coupled with elemental analysis to evaluate the surface removal efficiency. Three different types of feed materials were used to analyse the efficiency of surface removal using production attritioner scrubbers. This approach relates the downstream beneficiation plant’s expected performance with that of the attrition scrubber’s scrubbing efficiency.

Oct 5, 2011

By A Penney, M J. Pascoe, R M. Stephenson

The empirical McCracken and Stacey stability and risk assessment method has been in use for more than 20 years to assess geotechnical stability issues for raise bored shafts. The methodology has been applied with various levels of success. Increasingly, trends in mining and civil tunnelling have been towards larger diameter, single pass, raise bored shafts to rapidly provide means of ventilation, material movement (ore passes), or emergency egress. Identifying and assessing potentially problematic zones before raise boring commences can allow for appropriate risk-based decisions on construction, or to investigate alternative solutions. The implementation of a proactive solution to raising through an identified weak zone is preferred to the application of an engineered solution to an area subjected to substantial instability or failure. Methods for investigating potentially problematic areas are discussed in this paper based on AMC’s benchmarking data. Proactive investigation programmes resulting from these investigations are also discussed. Previous publications discussing the benchmarking data have concentrated on Australian case studies. Increased efforts and recent updates have been made to expand the database to include international case studies. This has provided further refinement of lower bound ‘raise bore rock quality index’ (QR) values, and various rock mass parameters for stability assessments. CITATION:Penney, A, Stephenson, R M and Pascoe, M J, 2018. Raise bore stability and risk assessment empirical database update, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 434–445 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By F M. Weir, M Fowler

A discrete fracture network (DFN) approach involves numerical modelling that explicitly represents how defects may be spatially distributed through a rock mass. A DFN is a 3D realisation of the ‘smaller scale’, non-deterministic defects; it is not an attempt to model larger, deterministic structures that should be identified as part of an engineering geology model. The approach utilises structural data in stochastic analyses to give a range of possible models that provides a tool for visualisation and analysis of a rock mass and indicates the potential large-scale slope or tunnel performance and stability.Stochastic fracture modelling for rock mass characterisation has significantly advanced over the past 25 years. With recent improvements to field data collection and computational power, it has become recognised internationally as a valuable tool for modelling some geomechanical problems encountered when designing excavations in fractured rock masses.This paper provides an introduction to the DFN approach, particularly the necessary input parameters and derivation of these from typical structural data sources, such as boreholes or scan line mapping. Of particular importance for engineering applications is validation of the simulated fracture network and techniques for doing so are discussed here.CITATION:Weir, F M and Fowler, M, 2014. An introduction to discrete fracture network modelling and its geotechnical applications, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 435–444 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

This paper reviews recent advances in geophysical tools for mineral exploration. It does not restrict comments to methods which are usually applied in the tectonically active belt surrounding the Pacific Ocean, where geophysics has often been secondary to geological prospecting (eg visual recognition of surface alteration) and drainage geochemistry; but considers geophysical tools applied to a broader range of both deposits and terrains. For example, the subdued topography of much of Australia and Canada has lent itself to the development and extensive application of airborne methods. In Australia, deep weathering and transported cover have necessitated the use of geophysical methods to not only detect anomalies but also to map and understand basement geology. This same weathering has caused specific problems, particularly for electrical methods, but recent improvements in instrumentation, processing and visualisation have largely overcome them. A great deal of geophysical data is now being collected by government agencies, often from the air, and made readily available to explorers. In several Australian states it is free, often on line, and in almost all cases it is relatively cheap. These regional data sets are often augmented by more detailed local surveys in areas of interest. Although æanomaliesÆ are still important much more is being done with the high quality data which is now available The results are used for geological mapping, to test geological hypotheses, to construct detailed 3D geological models and, together with fluid flow modeling, to predict optimum locations for mineralisation.

Jan 1, 2004

By M Berry, F MacCorquodale

The ownership, management and employment structures operating in the Australian minerals industry have dynamically evolved during the last 30 years. One of the most dramatic changes, from an exploration and mining geology perspective, is the reduction of in-house geological expertise and an ever increasing reliance on contract and consulting services.For all companies - big and small - two key issues resulting from these changes are the management of core geological intellectual property (IP) and competitive advantage. This is because there are less experienced geologists at exploration and mine sites, there are fewer head-office technical service teams to support mine sites, exploration teams are smaller with less specialists employed, and there is an ever-greater dependence on contract and consulting services.This paper reviews and explores these issues with an industry-wide geological context, then provides a case study of how Newcrest Mining Limited (Newcrest) has dealt with these issues in exploration. Newcrest has grown from a one-mine company with an Australian exploration focus, to a large global company with multiple operations and an extensive international exploration portfolio. NewcrestÆs management of its geological IP and competitive advantage has evolved as the company has grown and responded to market conditions, including its internal restructuring in mid-2013.CITATION:Berry, M and MacCorquodale, F, 2013. Managing geological intellectual property and competitive advantage - Newcrest Mining LimitedÆs experience, in Proceedings World Gold 2013 , pp 37-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013