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By S Furman, M Caccetta, A Hacket, B McDonald, M A. Wells, D Lau

In 2004, the Western Australian Department of Industry and ResourcesÆ Burrup Rock Art Management Committee commissioned a number of independent scientific studies to evaluate the condition of rock art in the Burrup Peninsula near Karratha (Western Australia). These studies are evaluating the physico-chemical aspects of the effect of environmental modification on the visible appearance of the rock art. Because of the cultural significance of the sites, the research approach has been to employ non-destructive testing strategies and work in the field has progressed with respect for the importance of the area. This paper only reports the spectral mineralogy monitoring at each of the sites to evaluate whether changes in mineralogy are observed on rock surfaces. Reflectance spectroscopy is a non-destructive, in situ materials characterisation technique that provides information about the mineralogy. The minerals detected include haematite, kaolinite, chlorite, goethite, gibbsite and manganese oxides. Current results indicate that the surface mineralogy of the rock art has not changed in the last four years.

Jan 1, 2008

A broad zone of intra-plate volcanism occurs for some 3000 km along the E. Australian coastal regions, extending from far northern Queensland southwards to Tasmania, westwards to western Victoria, and into southeastern South Australia. The age range, taken over the whole region, extends from Eocene to Holocene. Wellman & McDougall (1974) recognised the occurrence of three distinct types of volcanic occurrences: (a) Lava field provinces, dominantly basaltic and commonly strongly undersaturated, but of variable size. Large lava fields are especially exemplified by the younger provinces in northern Queensland (e.g. Nulla, McBride), and western Victoria. (b) Central volcano provinces, in which a reasonably well defined volcanic edifice is discernable. Such provinces are built of mildly undersaturated to saturated mafic lavas, but are also characterised by felsic volcanism (and often substantial mafic and felsic intrusive phases). Examples are the Springsure-Minerva Hills province, the Tweed and Focal Peak Shields (southeastern Queensland to northeastern N.S.W.), and the Nandewars, Warrumbungles, and Canobolas volcanic centres (N.S.W.). (c) A single leucitite province in N.S.W. Wellman and McDougall (1974) were able to show that the central volcano provinces exhibit a remarkably regular southward age migration pattern, the calculated migration rate being 66 + 5 mm yr , and these authors interpreted this in terms of the northward passage of the Australian plate across a fixed 'hotspot' within the upper mantle. The leucitite province also fits this migration pattern. The lava field provinces apparently exhibit more erratic regional age distribution patterns, but Sutherland (1981) has interpreted the data in terms of a multiple 'hotspot' model. It is noted, however, that the youngest areas of volcanism (Pleistocene 1. Department of Geology and Mineralogy, University of Queensland, St. Lucia, Brisbane, Queensland

Jan 1, 1987

By Q Qian, M Karakus, J Wang, N Melkoumian, D Goodchild, Q Sui, C Wang

Probabilistic analysis is widely used in slope stability assessment because of its capability to take into account uncertainties associated with geotechnical parameters. There are, however, still many unresolved practical issues to the application of the method. One of these issues is the integration of assessments when multiple sets of fractures are considered for the entire slope. In the present study, this issue is addressed within the framework of Monte Carlo simulation. Probability of failure for pairs of fracture sets are assessed independently and the final assessment of the probability of failure for the entire slope is done using conditional probabilities. Prominent Hill open pit, in particular, the problematic fresh Bulldog shale formation, was used as a case study to test the method proposed. The SWEDGE program of the RocScience software package was used for the analysis.

Sep 26, 2011

This paper presents a method for estimating the strength and stability of model coal pillars with bedding planes (weakness planes) inclination. The strength of coal relative to the angular difference between the principal stress direction and bedding planes is considered. The failure behaviour of model coal pillars containing weakness plane inclination by using servo-control Schenck Machine are shown. Uniaxial and triaxial compressive strength of coal specimens are investigated, and test results indicated that the strength of coal pillars depends on the weakness planes inclination with respect to the principal stress direction. However, it is shown that with increasing confining pressure, the effect of weakness planes inclination on the strength of the coal specimens is reduced. An empirical method is given for prediction the compressive strength of coal containing weakness planes inclination. The results of this method are compared with the experimental results and Jaeger theory. Finally, three well-known empirical strength criteria were tested against the triaxial test data for coal containing weakness planes inclination.

Jan 1, 1995

By de Brodtkorb MK

Late Cenozoic ore deposits "Precious and base metal-rich" and " Sn-Ag-polymetallic"of Northern Puna are associated either with Middle Miocene dacitic volcanic-dome complexes or with Upper Miocene dacitic-andesitic volcanic centers. Ore mineralogies and their related volcanism are discussed. A strong link is observed between the Cenozoic Metallogenetic Province of Northern Puna and the Southern Bolivia Tin and Polymetallic provinces.

Jan 1, 1995

By T P. Hynes

Submarine tailings disposal is conceptually an attractive option for managing reactive mine wastes in coastal regions by virtue of reduced sulfide oxidation under a water cover and no infrastructure to maintain after mine closure. However, the lack of detailed knowledge of metal leaching, dispersal of fine tailings and biological impacts in the marine environment has led to no operating permits currently in effect in Canada. Detailed chemical and ecotoxicological assessments at two historic copper mine sites (Little Bay and Tilt Cove) in the north coast of Newfoundland with tailings disposed in an estuarine to shallow (=100 m) marine environment have demonstrated reduced reactivity of sulfidic tailings when submerged under water. Only non-acute toxicity is detected in biota inhabiting the immediate vicinity (A review of another historic shallow marine tailings operation in the southern tip of Vancouver Island (Jordon River) with a high-energy setting also reveals problems with unconfined tailings dispersal and temporal biological impacts. Documented studies at two deeper (140 - 360 m) marine tailings disposal operations at the northern tip of Vancouver Island (Island Copper) and northwestern coast of British Columbia (Kitsault) again illustrate imperfect predictions of tailings re-suspension and dispersal. At these sites, bioaccumulation of tailings-derived metals appears to be minimal. There is evidence of rapid re-colonisation of the tailings surface by benthos but of different species than the original population. Integrating these observations with reported metal fluxes and biological diversity associated with submarine hydrothermal vents, the risks and benefits of deep-sea (>1 km) tailings disposal are discussed. To determine if submarine tailings disposal in deep, confined basins on the seafloor is environmentally friendly, detailed multi-disciplinary research incorporating physical, chemical, biological and toxicological components will be indispensable.

Jan 1, 2003

By R Skirrow, E Bastrakov, A Mauger, P

A new rapid spectroscopic core and chip logging and imaging system developed by CSIRO was evaluated by PIRSA and GA on a wide variety of mineralised properties in South Australia, including the Emmie Bluff, iron oxide copper-gold-style prospect on the Stuart Shelf. During a three-month campaign in South Australia in 2003 the system logged over 50 000 metres of core from the State Core Library, company prospects and mines. The new system uses automated core tray handling, continuous visible and infrared spectroscopy, and digital imaging, to characterise and identify dominant mineral species on core, chips and pulps, at spatial resolutions of ~1 cm (spectral data) and ~0.1 mm (image data). The system can log up to 1000 m of core per day and several thousand metres of drill chips. Mineralogy is pre-interpreted using specialised identification software trained on a selected suite of minerals showing characteristic absorption features within the measured spectral range. On core from the Emmie Bluff iron oxide copper-gold prospect, 470 km NW of Adelaide and 80 km SSE of the Olympic Dam Cu-U-Au deposit, the spectral mapping system was able to characterise a number of alteration zones enveloping the sub-economic Cu-Au mineralisation. These consist of distal white mica phases showing decreasing Al content towards mineralisation, a zone of increased iron oxide content in the hangingwall to mineralisation, and a zone proximal and coincident to Cu-Au mineralisation that is enriched in chlorite with variable Mg/Fe chemistry. Additionally the results show background spectral characteristics that mimic the magnetite distribution.

Jan 1, 2004

By Misra A

The development of roadways in underground mines in Autralia is by conventional continuous miner technology. The rate of development achieved using this technology is improved by modifications to this technology using additional equipment such as surge cars or decreasing roof bolting time.Development rates achieved with this technology compare with developing technologies such as high capacity continuous miners, continuous transportation and simultaneous cutting and bolting systems such as the Kemcol Beaver. Pillar dimensions have an effect on the rate of development.'

Jan 1, 1991

The recommissioning of the plant at Mary Kathleen involved several distinct phases. The previous plant process was modified significantly, the plant capacity was increased by the addition of new equipment and the exist- ing equipment was in most cases overhauled. This equipment was either reused in its original duty or relocated. Maintenance requirements after the plant was cmommissioned were high because of the amount of modified equipment and also because some old items of equipment were deliberately not overhauled during recommissioning. The equipment that was overhauled has operated reliably. However some new equipment has not been as satisfactory.

Jan 1, 1978

By J Tsiklieris, O Turner

Suppliers of products and services have a pivotal role in sustainable development in the mining and minerals industry. Reputable suppliers know their products and services, and the industry, and have unique knowledge of these in relation to their customerÆs needs. Petroleum hydrocarbon suppliers, in particular, impact upon a mineÆs sustainability because of the extensive reach of petroleum hydrocarbons into the mining and minerals life-cycle. The petroleum hydrocarbon life-cycle is a useful framework to enable engagement between supplier and customer on the issue of sustainability. The life-cycle starts with supply of fuels, lubricants and services at the mine, through to plant operation and maintenance, transport of mined products, ship loading, and finally through to mineral processing and other downstream value-adding. There are barriers to leveraging supplierÆs capabilities which have to be overcome before the industry will gain the potential benefits from such supplier engagement.

Jan 1, 2004

By Olden WH

A scheme is presented whereby the complexities of design and operation of a hydraulically powered coalmine support are modelled using the finite element method. This enables predictions to be made of the interaction of the support with its environment in a variety of operating conditions. The model is a two dimensional representation. The modelling scheme was applied in two case studies. In the first, the performance of a four leg support was uprated by increasing the front leg force. The finite element model enabled changes in overall support performance to be verified. In the second case study, the change in lateral force developed by a two leg support was assessed with changes in support operating height and floor foundation stiffness. The modelling scheme is capable of further development with the possibility of extending the model into three dimensions and the addition of control elements that would enable an actual mining sequence to be Represented.

Jan 1, 1992

The implementation, during recent years, of the concept of distributing chilled water to improve cooling at the working faces represents a very important innovation for the mining world. In a logical extension to that concept it has been recognized that distribution of the cooling water at high pressure would provide a potential source of energy for driving water powered hydraulic machinery such as rockdrills, water jets for moving rock, and support props, in the workings. With this in mind, the Research Organization of the Chamber of Mines of South Africa is pursuing the development of such a dual system that will provide cooling in a deep mine and, at the same time, drive hydraulic machinery. A comprehensive design of such a system has been completed and has shown the concept to be entirely feasible technically using technologies currently available. A pilot system is working in a mine shaft 2000 m deep giving a pressure of 20 MPa at the bottom of the shaft and distributing the cold water into the workings at a pressure of 17 MPa. The system shows considerable potential for improving existing mining methods and will open the way for the development of new mining methods for deep mining operations.

Jan 1, 1986

Cannington is a Broken Hill type deposit discovered by BHP Minerals, now BHP Billiton, in 1990. The deposit is located south east of Cloncurry, Queensland, Australia. The deposit occurs in the Eastern succession of the Mount Isa Inlier within the Soldiers Cap Group. The mineralisation is interpreted to be confined to two limbs of a synform wrapped around a core amphibolite. The silver, lead and zinc mineralisation is zoned within silicic and mafic units. There is a strong association between silver and lead. The combination of mafic and silicic zoning, differing relative grades of silver, lead, zinc and iron, the relative position of the mineralisation on the synform limbs and differing metallurgical performances have resulted in the identification of ten different ore types, four of which are currently extracted. Ordinary Kriging (OK) is used as the resource estimation methodology for the silver, lead and zinc mineralisation. This modelling approach has performed quite well for resource reporting and long term mine planning. However the limitations of this modelling technique to adequately provide information on a local stope scale has lead to the geological staff to consider alternatives to this approach. Limitations of the current modelling method apply to both the geometry of the orebodies and the grade variability. Since early-2000 the Cannington geologists have been experimenting with modelling both the distribution of the mineralisation types using Probability Field conditional simulation (PF) and the distribution of grade using Sequential Gaussian Simulation (SGS). This approach to local modelling of mineralisation type and metal grades using conditional simulation (CS) has undergone a full evaluation by comparing grades estimated for stopes using both the (OK) resource model and conditional simulation (CS) models. The mine planning staff have used the CS derived models, and have found improvements in grade predictions over the currently utilised Ordinary Kriging û derived resource model.

Jan 1, 2003

By L Reynolds

The portable infrared mineral analyser (PIMA) was trialled to determine the extent and intensity of any hydrothermal alteration halo associated with gold mineralisation in the Hyde-Macraes Shear Zone (HMSZ) of the Otago Schist.   Twelve diamond drillholes through the HMSZ were analysed with the PIMA at a sample spacing of 1 m. The drillholes were selected on two traverses along the line of strike and down-dip of the mineralisation in and around Panel 2 of the Frasers underground development.   The study showed that the Hangingwall shear of the HMSZ has a more distinctive infrared signature in intersections with high grades. The Hangingwall shear in these drill holes is defined by a shift in the wavelength of the Al-OH absorption feature from ~2220 nm to <2210 nm. This shift is attributed to a change in the mineralogy from phengite to muscovite. Overprinting this trend in some of the drillholes is the presence of the 2210 nm Al-OH absorption feature, ascribed to kaolinite. Kaolinite also tends to be present in numerous other regions of the schist above the Hangingwall shear associated with steeply dipping faults and foliation parallel joints. In drill holes with low grades the Hangingwall shear does not exhibit any obvious infrared signature.   At the scale of study, the PIMA does not provide evidence for an alteration halo associated with hydrothermal mineralisation above the Hangingwall shear. Possible tectonic movement may have displaced any alteration halo that once existed, away from the zone of mineralisation. For this reason, PIMA apparently cannot be used for predicting the location of the Hangingwall shear during exploration drilling. However, the study did show that the PIMA could define the Hangingwall shear when the rocks were sufficiently altered and mineralised.

Jan 1, 2007

In 1969, Queensland Mines Limited obtained two large Prospecting Authorities in Arnhem Land, Northern Territory, Australia. The Nabarlek uranium deposit containing some 12 000 t of U308 was discovered on one of these in June 1970. Mining and stockpiling of this deposit were completed in 1979 and processing to yellowcake, which commenced in June 1980, is expected to occupy an 8-10 year period. The continuation of exploration, essential for the company to become a longer- term producer, was inhibited in 1972 by a Federal Government "freeze" on exploration in Aboriginal Reserves in the Northern Territory. Subsequently, the procedure for explorers to gain access to exploration areas in Aboriginal land was radically changed by the proclamation of the Aboriginal Land Rights (Northern Territory) Act 1976. As a result of this Act and the associated administrative policies adopted by Governments, Queensland Mines Limited has not yet regained access to the exploration areas it formally held in the early 1970's.

Jan 1, 1986

Cut and fillstoping using hydraulically placed mill tailings has become an essential feature of stoping operations in Kalgoorlie. ' Approximately 30 per cent of the total production is currently mined by this method. Fill is prepared by thickening or cycloning and is gravitated or pumped underground. The average pulp density is 70 per cent solids by weight, Recent cost reducing innovations are the use of steel passes, corrugated iron manways, polythene film sealing, and the replacing of vertical cement lined pipes with boreholes. TTTTTI rvr T Trim r l1TT

Jan 1, 1964

Optimising drill performance has always been a primary goal of drilling and blasting managers. Improving drilling rates and utilisation will ultimately drive the cost per foot or metre downward. Additionally, more consistent production will ensure shovel or dragline performance goals are met and the chances of machine idle time is minimised. Over the past 20 years, many studies have examined rotary drilling factors and performance issues. In most cases a common theory points to energy input versus drilling output. Indexes such as specific energy and total work energy have been -developed to quantify the drilling process. As general engineering principles dictate, energy is required to drill rock by overcoming compressive and shear strengths. Concurrently, the greater the energy input, the faster the penetration output. Therefore, by examining the basic drilling energy parameters, optimisation is possible. The principles of rotary drilling are driven by five factors. When optimised individually and as a system, drill performance will improve. Most recent studies all agree that a performance relationship exists between bit load, bit rotation, and hole flushing. Additionally, proper bit selection and most of all, the operator, can have a tremendous effect on drill productivity. By analysing these factors and establishing the best case scenario, an overall drilling system can be engineered to match the mining characteristics. Furthermore, by balancing these factors, a lower cost will be achieved through increased production rates, maintenance costs, and effective drill utilisation.

Jan 1, 1995

Cataclysmic or flood-like release of gas-charged brines, hydrocarbons and slurries accompanied widespread mineralisation of Upper Devonian environments. These are well represented in the Canning and Burdekin Basins of Western Australia and Queensland respectively.The Burdekin Basin provides particularly instructive vein structural sequences. These fall into organic residue to carbonate paragenetic sequences which are known elsewhere to record progressive decarboxylation. Fibrous veins indicate overpressure in fractures with organic residues, acids and gas derivatives driven to overlying groundwater flows. This combination of large flow rates and potent organic mineralisers led to extensive arsenical rare-metal mineralisation which is similar to that concentrated in Upper Devonian extinction horizons of the Canning Basin. Organic-residue mineralisation appears concentrated by certain hvdrostructures and targeted upon particular species. These controls need to be understood to guide modern management stragegies for mineralised organic and nitrogenous wastes.

Jan 1, 1990

By Rongqing Q, Tiancong Z, Yiyuan L

The influence of pulp density, ferric ion concentration and particle size on the tank bioleaching of two kinds of refractory gold concentrates are discussed. The chemistry and mechanism of the bioleaching process are also presented. The relationship between oxidation of sulphides, liberation of enclosed gold and gold cyanidation are discussed. The consumption of NaCN could be reduced by alkaline treatment of bioleached residues prior to Cyanidation.

Jan 1, 1992

The crushing and concentration of ores, as Herbert Hoover commented in a footnote in De Re Metallica, stretches back at least 6000 years. During those years there have been continuing changes and improvements in mineral processing technology. It has expanded greatly in its ability to handle different types of minerals, and lower grade and more complex ores. Australia will be dependent on the mineral industry for the fore- seeable future and there will be continuing demands on the mill opera- tors to improve the technology with regard to efficiency, flexibility and costs. These demands will be met successfully in the future as they have been in the past. This Mill Operators' Conference is an important forum for assessing our present position and planning for the future.

Jan 1, 1988