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As world demand for various minerals increases the mining industry in its endeavour to satisfy this demand will, eventually,look to the extraction of orebodies which previously may have been uneconomical to mine. These orebodies may be of two types. Firstly, new low grade orebodies and secondly, remnant sections of previously mined orebodies. Some of the factors relative to remnant mining operations are discussed and the potent- ial of remnant mining in providing an important contribution to future world metal production is considered.

Jan 1, 1975

As world demand for various minerals increases the mining industry in its endeavour to satisfy this demand will, eventually,look to the extraction of orebodies which previously may have been uneconomical to mine. These orebodies may be of two types. Firstly, new low grade orebodies and secondly, remnant sections of previously mined orebodies. Some of the factors relative to remnant mining operations are discussed and the potent- ial of remnant mining in providing an important contribution to future world metal production is considered.

Jan 1, 1975

By Hopkins G. M F

Intensive exploration of the Archaean ultra mafic sequence bordering the Kambalda dome has resulted in the discovery of at least ten dis- tinct areas of nickel sulphide mineralisation subsequent to the initial drill intersection in January, 1966. Sulphide ore reserves to June 30, 1972 were 19.36 million tonnes at 3.3% nickel after mining of 3.0 million tonnes at 3:7%,nickel since production commenced in March, 1967. About 75% of contained nickel metal reserves occur in sulphide concentrations located at the base of the-ultramafic sequence, in contact with underlying meta-tholeiitic basalt. The remaining reserve occurs in concentrations of sulphides within the ultramafic sequence, usually within 100 metres of the underlying contact and typically in proximity to contact mineralisation. These hanging wall orebodies are smaller, contain significantly lower con- centrations of sulphide, and generally exhibit higher Ni:S ratios than underlying contact ore- bodies. The majority of contact sulphides concentr- ations form narrow, elongate, north north-west trending bodies, closely coincident with fault bounded depressions in the contact. Detailed study of the Lunnon Shoot ore environment in- dicates that it was a locus of crustal failure during, and subsequent to, emplacement of ultra- mafic rocks. Resultant structures parallel and

Jan 1, 1973

By C Sylvestre

For the last 50 years, traditional safety management has improved safety performance by: • Fixing the environment (eliminating the hazard). • Improving the system (more/less rules, procedures etc). • Making safety more conscious (more/better interactions about the importance of safety). Although these approaches certainly have merit, and may be part of an overall solution, they are not enough to prevent many modern-day incidents. Today, these three approaches are used more than before, and are used better than ever before. Yet, workplace fatalities in Australia have stagnated from 2013 to 2019, as have the number of incidents, even serious ones. In the USA, workplace fatalities have increased by 15 per cent in the same period.

May 5, 2022

By G Bignall, I Chambefort, A B. Christie, A J. Rae, M P. Simpson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Key indicator hydrothermal alteration minerals formed from fluids of known fluid composition (neutral versus acid pH) and temperature have been mapped for New Zealand (NZ) geothermal fields by visible/near-infrared (VNIR) and short wave infrared (SWIR) reflectance spectroscopy. Smectite, interstratified illite-smectite and illite formed from neutral pH fluids have zoned distributions with higher temperature illite (>220ºC) in and around the upflow of chloride waters and low temperature smectite (<150ºC) on the margins (eg Ohaaki, NZ). In adularia-sericite epithermal deposits, Au-Ag veins are similarly surrounded by zoned clays, with mineralised veins enclosed by illite (eg Martha, NZ) or occurring at the illite/illite-smectite boundary (eg Favona, NZ). Reflectance spectroscopy is also highly effective in identifying minerals formed from acid fluids; both steam-heated acid-sulfate waters (eg kaolinite and alunite at Rotokawa, NZ), or magmatic-hydrothermal fluids (eg pyrophyllite and topaz at Ngatamariki, NZ). These same alteration minerals commonly show zoned distributions in high sulfidation epithermal deposits (eg Rodalquilar, Spain) and in lithocaps associated with porphyry deposits (eg Lepanto, Philippines). Thus reflectance spectroscopy permits the rapid identification of key alteration minerals that can be mapped at a high sample frequency and used as vectors towards mineralisation.CITATION:Simpson, M P, Bignall, G, Rae, A J, Christie, A B and Chambefort, I, 2015. Mapping hydrothermal minerals in New Zealand geothermal fields using reflectance spectroscopy (VNIR-SWIR) and application to mineral deposit exploration , in Proceedings PACRIM 2015 Congress, pp 243–248 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The celebrations which took place in 1986 to mark South Australia's Jubilee 150 served to focus attention on all aspects of the State's heritage. Until that time the sites and relics of South Aus- tralia's early mines had been generally neglected. Marked by the ruins of enginehouses and littered with the remains of the massive technology of the Industrial Revolution, these sites have now been recognised as containing the threads of a fascinat- ing story. In the early days of settlement the economy of the Colony was based on land and farming. Droughts caused periods of economic depression which were alleviated by chance discoveries of gold, lead, silver, and copper ore. Some of the mines which were opened on the copper deposits were the largest in the world at that time and their names well-known throughout mining circles. Working by hand with primitive equipment, the early miners excavated vast networks of shafts and stopes often extending to great depths: at Moonta- Wallaroo Mines for example workings extended to 860 m below ground. Because of the presence of underground water, mining to these depths would not have been possible without the Cornish pumping engine. Operated by steam power these massive engines and their associated equipment were transported from Cornwall by clipper and delivered to the mines by bullock cart. At this time the engines were at the peak of their devel- opment and, although expensive to import and install, they were highly reliable: the engine oper- ating Hughes pump at Moonta worked continu- ously for sixty years without a major breakdown.

Jan 1, 1987

By Kershaw M. G

At the Risdon plant of the Electrolytic Zinc Company of Australasia Limited, impurities toxic to the electrolytic production of zinc metal, notably arsenic and antimony, have traditionally been coprecipitated when precipitating iron as ferric hydroxide. With the development of a new lead/zinc mine at Elura, New South Wales, it was anticipated that the concentration of impurities, particularly arsenic, in the zinc sulphide concentrates treated at Risdon would increase. This suggested that an increase in the capacity of the iron purification step in the Risdon plant would be required to cope with the higher input of these impurities.Laboratory investigations showed that the additional capacity would be achieved, either by a large increase in the amount of iron used as the "collector" in the process, or by a two-stage process. The latter approach was preferred as a increase in the amount of iron precipitated would lead to much higher operating costs and overloading of the existing equipment.In the two stage procedure, acidic iron bearing solution is added to solution feeding the first stage and most of the arsenic removed from solution when iron is precipitated from solution by neutralisation with limestone. Mter separation of the precipitated solids, acidic iron bearing solution is added to the solution, and remaining arsenic removed almost completely following neutralisation by limestone.This paper describes the laboratory and pilot plant results and the plant modifications required. Abrief account is also given of the operator training and acceptance in the use of the digital control facilities installed in the new plant.The new plant is working well and good solution purity is being maintained despite a substantial increase in the concentration of impurities in the raw materials.

Jan 1, 1990

By D Jones

The development, piloting and engineering design of an innovative water treatment system for process water produced by a uranium mine mill are described. The process incorporates lime/carbonate softening (Stage 1), reverse osmosis (Stage 2) and biopolishing (Stage 3) to produce water of quality suitable for release to the receiving environment. Comprehensive performance data are presented for each stage. The unique features of the proposed process are: recycle of the lime/CO2 softening sludge to the uranium mill as a neutralant; potential use of power station off-gas for carbonation; and the potential recovery and recycle of ammonia from the RO reject stream.

Jan 1, 2003

By A Olshina, C Willman, D Moore

GeoScience Victoria has completed quantitative assessments of undiscovered gold endowment in the northern parts of the Bendigo and Stawell Zones. The under cover area in the Bendigo Zone (10 000 km2) is likely to contain approximately 1000 t and at least 290 t of gold in undiscovered mesozonal orogenic gold deposits. For the under cover area in the Stawell Zone (30 000 km2), the estimates are approximately 1200 t and at least 200 t of undiscovered mesozonal orogenic gold. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By J Q. Shi, M Karakus, Y Liu

Predicting the spatial distribution of rock mass properties in cave mining is a critical challenge. In this study, we introduce a novel machine learning-based model to advance our comprehension of rock behaviour. This model specifically focuses on the spatial distribution of rock mass and mechanical properties, a crucial aspect of our understanding of rock mechanics. Our model is inspired by the recognition that neighbouring information serves as crucial prior knowledge for predicting the spatial distribution of these properties, wherein closer neighbours are likely to exhibit similar characteristics. To effectively capture and model these neighbour relationships, we design a neural network-based model to map the spatial locations within the data set into a new highdimensional space. Within this transformed space, we utilise Euclidean distance to identify N neighbours. Leveraging these neighbours, we introduce a straightforward yet highly effective approach—label propagation—to construct a graph that illustrates neighbour relationships. This graph not only facilitates the prediction of the spatial distribution of rock mass properties but also offers a measure of uncertainty for these predictions. We validate the proposed method using a real rock data set and showcase its efficacy in capturing intricate relationships and distributions within rock properties, enabling precise predictions across diverse spatial scales. Our results underscore the potential of machine learning-based approaches to revolutionise the field of rock mechanics, providing valuable insights applicable to geotechnical engineering, mining, and other sectors where an accurate understanding of rock properties is paramount. This model has direct practical implications, offering a new tool for geotechnical engineers and mining professionals to enhance their understanding and prediction of rock properties, thereby improving safety and efficiency in their operations.

Sep 1, 2024

By B K. Hebblewhite, G Sharrock

The strength and deformation properties of a rock mass are important parameters influencing the design of civil and mining excavations or structures. The mechanical behaviour of jointed rock masses are controlled by the characteristics of discontinuities and the strength of intact rock bridges between discontinuities. To date, analytical, empirical and experimental methods have not captured the key mechanisms controlling the mechanical properties of actual rock masses with non-persistent joints. The emergence of the synthetic rock mass (SRM) in 2007 provides a promising approach for this purpose. In this paper a rock mass with non-persistent joints is analysed with the SRM model based on PFC3D. The influence of joint geometrical parameters on the uniaxial compressive strength (UCS), rock mass deformation modulus (Em) and failure mode is studied. Joint parameters include joint orientation, persistency, spacing and step angle. Prismatic numerical samples with dimensions 300 mm × 150 mm × 50 mm were generated and a sensitivity analysis of each joint parameter on UCS and Em was undertaken. The results show that of the parameters tested, joint orientation has the greatest influence on UCS. Minimum UCS occurs when the angle between the major principal stress and joint surface is approximately 60°. The joint step angle was found to have a significant effect on failure mode and a joint step angle of 90° is the most favourable joint orientation for step-path failure. The importance of joint step angle is highlighted in the discovery of a failure mode bifurcation point at joint step angles of 60° and 90° for joint orientations of 75° and 90°, respectively. For these parameters the failure mode transitions from block rotation to a new failure mode where the coalescence of cracks results in the formation of new small regularised blocks.

Sep 26, 2011

By W Dodson

Major ions, d18O and d2H and Carbon-13 concentrations in groundwater from 30 bores near an open pit iron ore mine were used to better understand the chemical evolution of groundwater in the aquifer. The relatively depleted d18O and d2H isotopes of groundwater from various depths suggest that groundwater is recharged from intense rainfall events, with little evaporative effect. The 300 to 500 mg/L increase of major ions relative to that of rainfall is due to evapotranspiration of rainfall during recharge. Geochemical mass balance modelling suggests that the evapotranspiration of rainfall during infiltration through the unsaturated zone varies over six fold from 20 to 130. This coupled with the dissolution of CO2 from the unsaturated zone and partial dissolution of carbonates and gypsum from Tertiary sediments and carbonates from the Wittenoom Formation accounts for the current major ion, d18O and d2H distribution in groundwater. Despite the relatively dissected morphology and steep hydraulic gradient the results of this study highlight the dominance of vertical flow relative to horizontal flow. The study also shows the dominance of rapid recharge by significant rainfall events as an important component of the water budget for east Pilbara aquifers.

Jan 1, 2009

The author reviews design evaluation theory and existing optinustion tools and then describes how these have guided recent developments in Whittle Programming's strategic mine design package: Four-X. A new package - Reserve Estimator is also d

Jan 1, 1998

A study of the bacterial oxidation of naturally occurring high-purity sulphide minerals (FeS2, Fel_xS, CuFeS2, Cu2S) has been conducted using a mesophilic strain of T. 6ejtAooLcdcth4. As well as metal analyses and solution pH, partitioning of sulphide sulphur into elemental sulphur and sulphate ion has been monitored. Partially oxidised sulphide substrates have been characterised at regular time intervals by X-ray diffraction methods and extra-cellular organic compounds reporting into leach solution have been identified by'thin layer chromatography. The results indicate that the S¦/SO4 2 partitioning of the sulphide substrates is independent of cell inoculum size and initial pulp density and varies with solution pH, Eh, leaching time and mineralogical properties of the individual sulphide minerals. The signifi- cance of results for applications in selective flotation, coal desulphurisation and agglomera- tion has been outlined.

Jan 1, 1984

By Q Zhou, Y Ma, J Zhu, R L. Frost, P Yuan

A series of organoclays with different surfactant arrangements were prepared by ion exchange. The resulting organoclays were investigated using a combination of characterisation techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric measurement (TG) and N2 adsorption-desorption. In the present study, the pores within the organoclays were discussed on the basis of the micro- structural parameters, including BET-N2 surface area, pore volume, pore size, surfactant loading and distribution. The results show that both BET-N2 surface area and pore volume decrease from low to high packing density of the surfactant as the average pore size increases. Two basic organoclay models were proposed for hexadecyltrimethyl- ammonium bromide (HDTMAB) modified montmorillonites: 1. the surfactant mainly occupied the clay interlayer, and2. both the clay interlayer space and external surface were modified by surfactant. This study demonstrates that the pore structure of the resulting organoclays has a significant influence on the sorption efficiency and mechanism of p-nitrophenol onto the organoclays.

Jan 1, 2008

By Davies C. E

At present the source of virgin iron for steel produced in New Zealand is titanomagne- tite extracted from titaniferous beachsands. Some of these beachsand deposits contain extractable quantities of ilmenite as well as titanomagnetite and both minerals represent challenging sources of vanadium and titanium products in addition to iron. This study looks at some theoretical aspects of smelting these ores directly with coal rather than with electric power, and takes into consideration the properties of the raw materials, the thermodynamics of possible process routes and the background of the economics involved.

Jan 1, 1980

By Totterdell JM

The Permian-Triassic Bowen Basin and the Jurassic-Cretaceous Surat Basin evolved in a backarc tectonic setting behind an active convergent plate margin in eastern Gondwana. Several extensional (Early Permian; Eocene) and contractional (mid- Permian; Early Triassic; Middle-Late Triassic; early Late Cretaceous) intraplate deformational events are recognised in the basins. These can be correlated with similar events in the New England Orogen that was being deformed in the Late Permian- Late Triassic as a foreland thrust belt. The intraplate deformations were probably the consequence of plate interactions, including the accretion of terranes, at the ancient active plate margin, remnants of which now occur in New Zealand.

Jan 1, 1995

The role of marketing in the development of a new project will be affected by political, commercial and technical pressures. Marketing success will be determined by the ability to predict and react to tomorrow's environment. In the Australian coal industry there is an emerging transition from production to marketing orientation. As a result, greater technical awareness of customer needs will be required. In particular, the industrial product nature of coal markets will need to be recognised. Greater attention will also need to be paid to product options and quality in mine planning. Marketing personnel will become more involved at every phase of the development of a new mine.

Jan 1, 1983

In the Illawarra District of New South Wales, Mines were traditionally developed from the seabord. The advantages were close access to the working faces and a minimal depth of cover. Travelling times to the working faces have become prohibitive in many cases due to progressive westward development of the mines. As a result, additional vent- ilation shafts were sunk to service existing mines and new mines were established west of the Illawarra escarpment. Mining operations west of the escarpment are now being conducted at an increasing depth of cover and can be effected by gas related problems such as high seam gas emission rates and gas outbursts.

Jan 1, 1983

By D Akis, A Clark

The Lihir gold operation, located in the New Ireland Province of Papua New Guinea (PNG), approximately 900 km north of Port Moresby, was commissioned in 1997 under the management of the Lihir Management Company, a subsidiary of Rio Tinto. This management period ended in 2005 with Lihir Gold Limited (LGL) becoming self-managed. LGL is now the largest listed company in PNG and a top tier mining company in Australia. The focus of the operation since 2005 has been to take advantage of strong market conditions to increase cash flow while driving operating costs into the lowest quartile of gold producers. During this period production has increased through capital expansions, most notably with the addition of a flotation circuit, and through culture change and efficiency improvements. The next step forward for the Lihir operation is a major plant upgrade to increase production to an average of around one million ounces per annum by matching the ore processing rate to the ore mining rate. The key benefits of this project will be the addition of approximately 240 000 ounces per annum of gold production, the access to an additional one million ounces of gold and the ability to meet all stockpiling requirements. The Lihir operation has come out of the boom period in a strong position, is undertaking a major upgrade at a time when prices are low and labour is available, and will be positioned to take advantage of future opportunities as they arise.

Jan 1, 2009