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By E Amini, M Scott

Grade Engineering® involves the planning, integration and operation of coarse preconcentration techniques to reject uneconomic material as early as possible in the mining value chain to improve the quality of ore delivered to mineral processing activities. These preconcentration techniques include screening for natural and induced deportment of grade to finer size fractions during blasting and coarse breakage, sensor-based measurements of grade and mechanised sorting at particle or bulk scales and coarse gravity separation. Over the last decade, the Cooperative Research Centre for Optimising Resource Extraction (CRC ORE), with the support of its participants, has developed a framework for the holistic evaluation of economic and production impacts attributable to these preconcentration techniques. The framework combines the characterisation of preconcentration responses, geostatistical modelling, process modelling and simulation of downstream and upstream production impacts and the optimisation of strategic mine plans to quantify changes in net present value due to different preconcentration strategies. This framework has been applied to evaluate preconcentration techniques at numerous metalliferous operations and can also be used to quantify changes in the environmental metrics for energy, water and steel consumption and emission, tailings and waste rock production. This paper collates the results of these Grade Engineering® studies to show the range and magnitude of economic and environmental impacts attributable to preconcentration. The studies have shown that rejection of uneconomic material prior to mineral processing activities can have a pronounced improvement in energy, water and comminution steel productivity, emission intensity and the profitability of metalliferous mining.

Nov 10, 2020

By T Muzondo, C Prins, D De Vaux, R Schouwstra

The Mogalakwena Platinum Mine in the northern limb of the Bushveld Complex is Anglo American PlatinumÆs only open cast operation exploiting the Platreef. The Platreef, which extends along the basal contact of the Bushveld Complex, is geologically and mineralogically a much more complex orebody than the Merensky and UG-2 reefs. Changes in the footwall and the genesis of the Platreef translate into a number of rock types being present. These rock types vary in hardness and recovery potential and present challenges to metallurgical staff trying to optimise the concentrator. A true understanding of the implications of treating these rock types is required if the maximum value from this orebody is to be obtained.In order to more accurately forecast production and incorporate ore variation in the mine plan and comminution and flotation circuits, a geometallurgical approach to managing the operation has been used and is being further developed.CITATION:Schouwstra, R, De Vaux, D, Muzondo, T and Prins, C, 2013. A geometallurgical approach at Anglo American PlatinumÆs Mogalakwena Operation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 85-92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By V Matousek, A Sellgren, R Visintainer, G McCall

A 4-component model for settling slurry pipe flow has been previously described by Wilson et al (2006) and Sellgren et al (2014) to predict pipeline friction loss (hydraulic pressure gradient) over a range of slurry compositions: from fine to coarse particle size, narrow to broad particle size distribution, and low to high solids concentration. The method applies a weighted average of established pipeline models for various settling slurry flow regimes, according to the volume fraction of solids falling within the applicable size range for each model. Further development of the model was undertaken by Visintainer et al (2017a, 2017b), based on a comprehensive set of laboratory tests in 203 mm (8 inch) and 103 mm (4 inch) pipelines, and it was also adapted to the modelling of slurry pump performance derates. However, this work was all performed with solids having a specific gravity near 2.65, as is typical for many mineral processing and dredging applications. The goal of the present work is to test the applicability of these models for settling slurries having a higher solids specific gravity, as may often be seen in the mineral processing of iron ore deposits. To that end, a test program was carried out in a 103 mm (4 inch) pipe loop using various compositions of an iron ore product having a solids specific gravity of 4.75 and containing both coarse and fine solids. By screening and flushing operations, a range of particle size distributions were created having different proportions of the coarse and fine elements. In all, 19 tests were performed with d50 particle sizes ranging from 50 μm to 3.2 mm and delivered solids concentrations from 10 per cent to 43 per cent by volume. Particle size distributions varied from very narrow to very broad, with d85/d50 ratios ranging from 1.75 to 26. Pipeline pressure gradient and pump performance data were collected and used to test the applicability of the previously developed 4- component models and to propose improvements to the models for the handling of high-density solids.

Nov 8, 2021

By M Saghaeian, V Sheikhzadeh, R Hejazi

Mining dilution is one of the most important factors affecting the economy of mining projects. Instead of quantifying dilution in mining studies, it is common to assume a general dilution such as 5 per cent for massive deposits. Dilution increases the operating costs in the plant by increasing the tonnage of material to be milled. It prolongs the mine life by reducing plant’s effective capacity. It also reduces the feed grade. In most cases, lower feed grade means lower plant recovery. Dilution also increases the cut-off grade, which in turn reduces the overall ore utilisation of a mine. In this study has been investigated applying pre-concentration by dry magnetic separation for decreasing of dilution impact on reserve estimation and open pit design in low-grade iron ore mine. Based on the preliminary open pit design and assumption 3 per cent as dilution factor, the mineable ore in life-of-mine (measured + indicated) has been estimated with Fe = 25 per cent, SiO2 = 49.7 per cent. Based on the experimental test work on the ore, by dry low intensity magnetic separation of dry HPGR product grinding circuit, it is possible to remove diluted waste material and liberated gangue before concentrate plant, so that around 34 per cent rejected and Fe grade increase from 25 per cent to 33 per cent and by weight recovery 66 per cent. The results of the test work showed that this methodology could decrease largely the impact of dilution in the feed to the plant. It also slightly effect on the reducing of dilution factor impact for open pit design and optimisation and leads to increase the mineable tonnage in the low-grade magnetite iron ore mine.

Aug 24, 2022

By L Q. Amorim

The mining district of the Quadrilátero Ferrífero (QF) in southeastern Brazil contributes to 70 per cent of the Brazilian iron ore production, which reached 370 Mt in 2010. Traditionally, four iron ore types were mined in the QF region:1. soft haematite,2. hard haematite,3. friable ‘itabirite’ (the Brazilian name for metamorphosed banded iron formation), and4. canga (an indurated iron-rich crust).With the exception of the hard haematite, these categories derive from supergene enrichment of the Paleoproterozoic Cauê Itabirite. High current iron ore demand means that the QF high grade supergene ores will be depleted in a few decades. Consequently, several mining projects are being developed to exploit unenriched, fresh itabirite. Among them, the Mineração Usiminas Serra Azul project in northwestern QF is one of the most advanced. Four major itabirite types occur in the QF region:1. siliceous (or standard),2. dolomitic,3. amphibolitic, and4. magnetitic.The dominant type in Serra Azul region is a fresh siliceous itabirite, composed essentially of haematite, martite and quartz that averages 36 per cent Fe (51.5 per cent Fe2O3) and 47 per cent SiO2. The second type, the magnetitic itabirite, consisting of magnetite, martite, gruneritecummingtonite, quartz, dolomite, stilpnomelane, and subordinate haematite, is typically a strongly magnetic greenish banded iron formation with the iron grade varying between 25 and 35 per cent. Chemically, it differs from the siliceous itabirite due to the relatively high CaO, MgO and, consequently, high LOI contents. Together with supergene ores, fresh itabirites have been included in the ore reserves of the Serra Azul project. We anticipate that all the four types of fresh itabirite will be incorporated as ore in the QF region, causing a huge increase on the iron ore resources of the district, and representing enormous environmental and technological challenges for the local iron ore industry.

Jul 11, 2011

Permeability and fluid pathways in fracture-controlled hydrothermal systems are governed by a dynamic competition between permeability-creation processes and permeability-destruction processes. Permeability evolution is coupled with the evolution of fluid pressure and stress states. Key permeability-creation processes are micro-scale to macroscopic fracture growth, and the generation of damage zones during co-seismic slip on faults or aseismic creep on faults and shear zones. The competing permeability-destruction processes include crack-healing and sealing, compaction and pore cementation. High rates of permeability destruction in hydrothermal systems require ongoing permeability enhancement to sustain high fluid fluxes and ore genesis.   In aseismic regimes, competition between permeability-creation processes and permeability-destruction processes can lead to continuous flow in deep level hydrothermal systems. However, in seismogenic regimes, rapid co-seismic permeability-enhancement is followed by progressive permeability-destruction in the intervening interseismic periods, and leads to episodic flow. The results of high pressure experiments are used to illustrate how pore fluid factors and stress states are dynamically coupled with permeability evolution in hydrothermal regimes. Particularly in the seismogenic mid- to upper crust, large changes in permeability during the seismic cycle govern relative rates of change of fluid pressure around active faults and shear zones. Rapid, post-seismic recovery of pore fluid pressures, relative to rates of shear stress recovery, leads to growth of hydrofracture networks prior to successive fault rupture events.   Pre-rupture hydrofracture networks do not develop where post-rupture fluid pressure recovery is modest relative shear stress recovery. At elevated temperatures, low rates of pore fluid pressure recovery relative to shear stress recovery promote ductile shear failure and grain-scale permeability enhancement within shear zones prior to rupture events.   The influence of pore fluid pressure cycling, shear stress cycling, and deformation processes in controlling the evolution of permeability, flow localisation, and flow anisotropy at the deposit scale are illustrated for mesothermal and epithermal lode gold systems.

Jan 1, 2005

By B P. Micke

Central Norseman Gold Corporation was established in 1935 and has been mining on the Norseman field in Western Australia since then. It is Australia’s longest continuously operating gold mining operation at nearly 80 years, although it has had its periodic challenges in the intervening years.Over the last 40 years, a series of open pit mines around the Dundas Goldfield have supplied lower cost mill feed to the Phoenix Mill at Norseman from time to time but this has largely come to an end for the foreseeable future. Now that underground ore sources are once again the principal mill feed, there are several challenges to be met for an ongoing profitable operation.During the last 20 years, there have been three different owners and this has affected the manner in which the operations were managed quite significantly. These differing approaches are contrasted and examined in some detail from both the operational and financial aspects.Planning of a downsized operation to ensure sustainable profitability in the future in a mining environment where there has rarely been more than two to four years of reserves ahead of the mill for planning purposes has been a significant challenge. Several of the options examined are described, including alternatives for future mine development.CITATION:Micke, B P, 2014. Managing the margin at Norseman, Western Australia – a case study, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 119–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By A Atkins

Six recent case studies were selected based on the eight main causes of mine disasters (Table 1; Quinlan, 2014) and where credible information sources, such as Royal Commission Reports, Coronial Investigations and textbooks, were available. The six case studies are listed below. Details are available via this link or the conference PowerPoint accompanying this paper. 1. Beaconsfield, Tasmania – 2006 Fall of Ground/Seismic Event (Chandler, 2009; Melick, 2007; Wright, 2012). 2. Bingham Canyon, USA – 2013 Manefay Slide (Ross, 2017). 3. Bronzewing, WA – 2000 Hydraulic Fill Inrush (Hope, 2002). 4. Brumadinho and Samarco, Brazil – 2015 and 2019 Tailings Storage Facility (TSF) failures (Bowker, 2019; Darlington et al, 2019; Demajorovic, Lopes and Santiago, 2019; Morgenstern, 2016). 5. Northparkes, NSW – 1999 Cave Air-blast (Bailey, 2003; Hebblewhite, 2003). 6. Pike River, NZ – 2010 Methane Gas Explosion (Macfie, 2013; Panckhurst, Bell and Henry, 2012.

May 5, 2022

By C R. Fountain, R J. Sinclair

The zinc industry is dominated by the electrolytic zinc (EZ) process. The EZ process has a low tolerance for impurities, resulting in tight concentrate specifications. Many mining companies sacrifice zinc recovery in order to meet smelter specifications. Some have ore-bodies that cannot be economically developed because too much metal has to be sacrificed, or it is just not possible to meet the specification. The BUKA Zinc Process (BZP) has been developed as a method of producing high-quality zinc from a wide range of concentrates. It can have lower capital and operating costs than the conventional zinc and lead production routes. Advantages accrue from increases in metal recovery during concentrating, smelting and refining; the elimination of most of the capital and operating costs associated with lead smelting; reduced transport costs; lower zinc refining costs; reduced refinery residue disposal costs; and reduced future environmental liabilities. This paper describes results of testwork that has been undertaken to demonstrate the viability of the BZP on both test rig and laboratory-bench scale.

Jan 1, 1998

By H Turrer, M Badawi, R Belissont, Y Foucaud, E Kleiderer, L Southavy, J Mesquita, Y Basselin

The Mont Reed iron ore deposit, owned by ArcelorMittal, is situated approximately 140 km southwest of the Mont-Wright mine in the southern region of the Labrador Trough, Canada. Acquired by Québec Cartier Mining (QCM) in the 1960s, the Mont Reed mining property has remained unexploited due to the complex nature of the ore in the area. However, during the last years ArcelorMittal’s R&D team has been dedicated to developing a process to beneficiate the Mont Reed ore and produce high-quality pellet feed suitable for direct reduction furnaces. Extensive research revealed that achieving a good liberation degree of particles required grinding the material below 75 μm (P80 of 53 μm). To find the most effective technology for this task, a detailed comparison between ball mill and vertical stirred mill grinding was conducted. Both grinding technologies underwent detailed testing in bench-scale experiments. The ground products were comprehensively characterised, including size distribution analysis and chemical analysis per size fraction. Additionally, liberation analysis was performed using an automated scanning electron microscope (SEM). To determine the grinding specific energy, a method previously developed at Samarco (Brazil) for fine grinding of iron ores was employed. Furthermore, magnetic separation and flotation tests were conducted on the ground products. After a thorough evaluation of all the results, it was observed that both ball mill and vertical stirred mill grinding produced samples with similar physical characteristics. However, the vertical mill demonstrated higher efficiency in grinding the material. To conclude the study, an economic evaluation was conducted for both options considering various factors. Overall, ArcelorMittal’s R&D team’s dedicated efforts have brought them closer to unlocking the potential of the Mont Reed ore deposit and paving the way for its future utilisation to the production of high-quality pellet feed.

Sep 18, 2023

By S Maritsa, E K. Chiw, S M. Masuka, ika, T Chisahwira

The challenges facing the iron and steel industry on a global scale include depletion of resources, excessive energy consumption and CO2 emissions. The demand for iron products in Zimbabwe is increasing due to massive infrastructural development like the expansion and improvement of mines, transportation systems and water reticulation systems. In Zimbabwe, cast iron is mainly produced from recycling scrap metals. However, there is currently a shortage of scrap, which has resulted in the vandalism of state-owned properties such as bus terminals and railway wagons and lines. Nevertheless, Zimbabwe is rich in limonite ores, which are idle, and it is the aim of this research that this ore be effectively used to produce feed for the blast furnace. The Blast furnace is still the dominant route for producing cast iron where sintering and coking processes are the main routes for preparing the Blast furnace feed. Sintering limonite ore fines produce a product of poor grade because of the high value of loss on ignition that has a negative impact on Blast furnace efficiency. Furthermore, the sinter plant and the coke making plant are a source of huge environmental pollutants. Since low-grade Zimbabwean coal fines are also available in abundance, they were used in the preparation of the composite materials ensuring maximum utilisation of this resource. Results showed that the limonite ore-carbon composite pellets sample with the binary basicity ratio (CaO/SiO2) of about 0.27 and coal addition of 2.5 wt per cent achieved above the minimum physical quality requirements for pellet of drop number of at least 4, a dry compression strength greater than 2.2 kg/pellet and an indurated compression strength greater than 250 kg/pellet. Limestone was used as the binder avoiding the addition of more impurities from bentonite since the limonite ore has a high SiO2 content of about 8.78 wt per cent.

Sep 18, 2023

The Grootegeluk coal beneficiation plant is situated near Ellisras in the Waterberg coal= field in the Transvaal, RSA. At this plant 15 million tons of coal bearing material per annum are beneficiated by means of two-stage heavy medium bath and cyclone plants. Because of the very low yield of 12 % coking coal product, run= ping costs are of the - utmost importance. For this reason extensive tests were carried out to establish the most effective crushing and bene= ficiation methods and suitable aquipment. At the second heavy medium separation stage, the near-gravity material (+ 0,1. g/cc) amounts to 45 % and daily plant performance ana=lysis is required to ensure acceptable plant efficiency. Beneficiation processes for the -0,5 mm coal originally considered were froth flotation, shaking tables, heavy medium cyclones and water- only cyclones. When the froth flotation route was decided upon, further test work was done to enable selection of the equipment most suitable for the particular requirements.

Jan 1, 1987

By J W. Dong, Y M. Li, J L. Tian, Z H. Jiang

Electroslag remelting is widely used to produce various special steels, mainly because of its ability to provide high cleanliness and excellent homogeneity of ingot. Undoubtedly an optimal slag plays a key role in removing inclusions and enhancing the mechanical properties of a specific special steel. In order to improve the metallurgical performance of the slag in electroslag refining of die steel, a variety of slags have already been developed using traditional trial-and-error methods. Nonetheless, these slags may not be inherently optimal for the specific requirements of actual die steel refining processes. In this work, we have designed a CaF2-CaO-Al2O3-SiO2-MgO quinary slag system using genetic algorithms method aiming to remove the existing large size inclusions (D and Ds type) in high quality die steel. The comprehensive effects of five components (CaF2, CaO, Al2O3, SiO2 and MgO) were studied based on existing fundamental theory. The slag composition was screened considering the parameters such as melting point, electrical conductivity, calcium ion concentration, and appropriate viscosity etc. Furthermore, the candidate optimal slag was applied in the industrial production of die steel by electroslag remelting method. The detection results indicate that majority large inclusions (D and Ds type) have been successfully removed, showing significant advantage to traditional slags. This result has demonstrated the genetic method to be efficient and reliable. In addition, depending on the personalised demand of other steel and alloys, this method allows for the adjustment of the screening frameworks and processes to develop the candidate optimal slags. This method has not been reported previously in the field of electroslag composition design, and compared with the traditional trial-and-error method, the new method will save a lot of time and experimental costs.

Jun 19, 2024

By S Bluhm, LádeáOliveira, R Funnell

Taquari Vasouras potash mine (Vale Fertilizantes) has many interesting features including virgin rock temperatures of 50¦C at depths of 700 m. The mine has a relatively small shaft system with limited ventilation carrying capacity, which was not adequate to exploit the full extent of the deposit. This limitation was overcome by installing two large-scale recirculation systems with underground reconditioning centres. This paper describes this unique mine ventilation and cooling system and some of its history over the past two decades. The two controlled recirculation systems have been operating safely for some ten years and the use of large-scale recirculation has been a fundamental component in the increase of production and extending the mining further-and-further from the shaft centre. The recirculation systems have played a huge role in the mine profitability and comprehensively extending the mine life. The paper also discusses a number of novel design and operating features such as reverse running pumps for energy recovery. The underground chilled water system design required a number of special safety features in order to minimise the risk of water leakage since this could be catastrophic in a potash mine. This paper describes a good example of a mine in which the final ventilation and cooling system design ends up very different to what was envisaged at the greenfields stage.CITATION:Bluhm, S, Funnell, R and de Oliveira, L, 2013. Controlled recirculation and refrigeration at ValeÆs Taquari Potash Mine, in Proceedings The Australian Mine Ventilation Conference , pp 237-248 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By H F. Yu, S Ueda, J Diao, W F. Gu, Y Sasaki, H Qin

The main reason for the underutilisation of steelmaking slags is their instability, which is influenced by their complex phase structure. Recycling and sustainable steelmaking slag face challenges due to the presence of magnesium oxide (MgO), a crucial component in steelmaking slag. This study investigates the phase evolution of steelmaking slag during the cooling process with different MgO contents, using high-temperature experiments and FactSage™ software, ver 8.1, (by Thermfact/CRCT and GTT-Technologies) thermodynamic equilibrium calculations. X-ray diffraction (XRD) and scanning electron microscope - energy dispersive x-ray spectroscopy (SEM-EDS) analyses identified main phases in steelmaking slag, including Ca2SiO4 (C2S), RO (MgO-FeO solid solution), Ca2Fe2O5 (C2F), and Ca3SiO5 (C3S). The study reveals that RO phase increases as the MgO content increases. C3S precipitates from steelmaking slag with a 12 mass per cent MgO content at a reduced temperature of 1400°C. It is important to note that C3S remains in the steelmaking slag even after slow cooling. This may be due to the substitution of Ca2+ in C3S by Fe2+ and Mg2+ ions. Intriguingly, the precipitation of f-CaO in steelmaking slag with 10 mass per cent of MgO content occurred after one year, while there was no manifestation of f-CaO precipitation in the steelmaking slag with 12 mass per cent of MgO content even after one year. This discrepancy suggests a potential stabilising effect of an appropriate amount of MgO in steelmaking slag. However, it is crucial to emphasise that this inference lacks supporting data, necessitating further research to validate this hypothesis. The significance of this work is in uncovering the complexities of steelmaking slag behaviour, providing essential insights for optimising recycling processes. The research sheds light on the factors that influence the phase composition and stability of steelmaking slag, contributing to the utilisation of steelmaking slags, promoting environmental sustainability, and enhancing the overall efficiency of metallurgical processes in the current industrial landscape.

Jun 19, 2024

Any Australian who knows of the poverty of the early settlers in the first few years following the arrival of Captain Arthur Phillip with his "first fleet" at Botany Bay must feel proud of the progress that has been made in the 174 years that have elapsed since that momentous occasionGFor all its attractive appearance as reported by Captain Cook and Sir Joseph Banks, the shores of Botany Bay and of Port Jackson proved most ,inhospitable, and the accessible country surrounding them anything but suitable for sustaining the life of the small settlement. It is well known that during the first 15 or 20 years the hardy colonists and un-tfortunate convicts were close to starvation on several occasions and were only saved by the arrival of supply ships, which were dependent on the vagaries of wind and current, and the hazards of the uncharted seas they had to -navigate-.When Australia was little more than a miserable penal settlement, Great Britain was one of the great-powers of the world, and the U,.S.A. was an independent nation with a growing degree of prosperity that even then gave promise of its mighty awakening to become, as it has, a e.olossus of industry and commerce,-and the. leader in living standards of the world to-day.Australia, from such a shaky, and comparatively recent start, has risen to a position in which its living standards rank very high in comparison with those of most of the nations of Europe and America. Exact com-parisons are hard to fix because of the wide variety of factors involved .but the Institute of Pab?Lic Affairs .(Victoria) places Australia fifthin the world, excelled only by the U.S.A., Canada, Sweden and Switzerland. The next best after Australia are the United Kingdom, West Germany and France.How we achieved such a high standard of living is a vast subject for study but some of the economic aspects of our climb from abject poverty to a position of near affluence can readily be identified.

Jan 1, 1962

By G Harbort

The use of geological data for optimisation of operating plants has become a significant part of the modern process mindset. The underlying principle is to convert spatial geological data into metallurgical information to drive production and mine planning, blast design, blending strategies and plant set-up. Increasingly the process designer is required to interface with geological and mining staff to propose the best investment strategy for a project’s benefit.The geometallurgical model development for the Zafranal copper-gold project commenced in March, 2010, several months after the start of a major drilling campaign by AQM Copper Inc. The initial evaluation stage required review of historical Teck RC data to determine areas of metallurgical interest within the project. As drilling transitioned from RC to diamond drilling, core that was considered representative of the resource was selected and subjected to MLA mineralogy analysis. When coupled with sequential copper analyses this allowed calibration of an assay derived mineralogy model, allowing process concept options and a preliminary test program to be developed. This Phase 1 test program provided a preliminary process design, operating costs and anticipated concentrate grades and recoveries. Both this data and resource estimation were used to generate a preliminary Whittle pit optimisation based on maximising net smelter return, which in turn fed into a preliminary mine plan. The preliminary mine plan, in conjunction with geological logs and core results was used to develop a phase 2 metallurgical test program, where variability tests were conducted throughout the resource and composites formed to investigate specific years of the mine plan in locked cycle flotation. In addition comminution tests were modelled against geometallurgical domains allowing comminution components values to be calculated for 36?000 m of core. A flotation geometallurgical model was developed and incorporated into the resource model allowing concentrate grades and recoveries to be estimated on a block-by-block basis.

Sep 5, 2011

The Que River and Hellyer polymetallic massive sulphide ore bodies are located 3 kilometres apart in the Cambrian Mount Read volcanics of Western Tasmania. Both deposits are classic examples of the Kuroko volcanogenic style. Base and precious metal rich hydrothermal solutions rose through a deep fracture system and vented on the sea floor, causing sulphides to accumu- late in adjacent topographic lows. Together the preproduction geological resource is approximately 23 million tonnes at greater than 18% zinc plus lead, with economically significant silver and gold. Exploration by Aberfoyle in the Mount Read volcanics com- menced in 1970. Que River was discovered in 1973 following a comprehensive data review, a regional stream geochemical survey and a helicopter-borne electromagnetic survey. Production began in 1981, and the mine is currently producing 300,000 tonnes per year. The ore is sold to the Electrolytic Zinc Company of Aus- tralasia Ltd mill at Rosebery. Ten years of extensive geological mapping, soil geochemistry, and induced polarisation, combined with continual study of the Que River orebody and its host rocks, formed a strong frame- work for the discovery of the Hellyer deposit, which was found as a result of drilling .a subtle time domain electromagnetic anomaly in 1983. Hellyer is currently being mined at a rate of 250,000 tonnes per year, with the ore being concentrated at Aber- foyle's converted Cleveland tin mill. Treatment of 1 million tonnes per year will begin in early 1989 at a new mill located near the Hellyer site.

Jan 1, 1988

By R Wedmaier

Henty Gold Mine is an underground operation producing 100 000 ounces of gold per annum. The original mining method used was flatbacking with paste fill. However, a non-entry method û uphole benching û was introduced in 1998 to recover the deteriorating crown pillars. Initial challenges were encountered, including poor drilling accuracy, difficulty in charging holes and poor rise performance. These challenges were overcome by a Continuous Improvement Team, consisting of mining engineers, supervisors and miners. Following this, the Team implemented further changes aimed at reducing ore loss and dilution. A second area addressed by the Team was development blasting, where innovative detonator technology known as the ExelTM DevelDetTM was introduced and rapidly accepted by the operators. Continued use of the ExelTM DevelDetTM resulted in a number of benefits, such as easier bogging, less perimeter damage, faster charging and hook-up and decreased wastage. Finally, improvements were made in the area of explosive handling, where competency-based training of operators was conducted and manual handling of ANFO has been significantly reduced by the introduction of the MiniMoverTM into the underground magazine.

Jan 1, 2001

Many persons hold the opinion that the metal indus- ries are fortuitous and that the occupation is one of sordid toil, and altogether a kind of business requir- ing not so much skill as labour. But as for myself, when I reflect carefully upon its special points one by one, it appears to be far otherwise. So wrote Georgius Agricola in 1556. He could have been espousing the sentiments of an indus- trial archaeologist investigating mining sites in 1986. South Australia has a very rich legacy from its industrial past-especially in the area of its mining history. Industrial archaeology, which is part of the broad field of archaeology, is concerned with the material and documentary remains of this industrial past. This includes the products and processes of manufacturing, industrial, technolog- ical and engineering activity and their relation- ships to people and the environment. `Archaeology' immediately conjures up the image of excavations in Greece or Eygpt. Excavation however is only a part of archaeological methodology. Industrial archaeology utilizes documentary historical rec- ords combined with field survey techniques (both above and below ground) to create a composite picture of the past. Interest in our recent past has burgeoned in Australia in the last few years. This interest manifests itself in many ways-the unprecedented popularity of Australiana and col- lecting, the plethora of Australian historic films, the growth of the National Trust, local historical societies and genealogical research. Fortunately these trends have been reflected in academic and legislative circles. Various univers- ities, institutes of technology and colleges of advanced education run courses in aspects of cul- tural resource management and conservation of the historic environment. These courses are com- prised of archaeology, architecture, geography, his- tory, materials conservation, museum studies, and national parks management and planning.

Jan 1, 1987