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The success of the In-Plant dust collection at the Albion Reid Quarry Plant situated at Para Hills, South Australia, is discussed in the light of co-operation at the design stage with particular emphasis on the duct- work and filter design. Other dust control facilities at the Plant are mentioned.

Jan 1, 1976

By H R. Watling, W van Bronswijk

Of the various copper sulfides in the EarthÆs crust, chalcopyrite is by far the most common. This mineral is also the most difficult to leach, with hydrometallurgical extraction processes characterised by prohibitively slow kinetics. While a number of processes, including leaching at atmospheric pressure and temperature, pressure leaching at higher temperature, and bioleaching of concentrates in stirred tanks and whole ores in heaps have been demonstrated to some extent, there is currently no full-scale unit process for the hydrometallurgical extraction of copper from chalcopyrite ores. Titan Resources NL operated a test bacterial heap leach at Radio Hill, Western Australia in 2001, to extract nickel and copper from a mixed sulfide ore that contained significant amounts of chalcopyrite, pentlandite and pyrrhotite. A proprietary mixed bacterial culture was used to inoculate the heap, and the nickel and copper were precipitated from the resultant solution as mixed hydroxides. Although 65 per cent of the copper from the Radio Hill heap was eventually recovered, the rate of extraction followed an unexpected trend, as the initial rates of copper recovery were much slower than column tests had suggested. It was postulated that this was due to dissolved copper precipitating as covellite or chalcocite in the most poorly aerated zones within the heap, ie furthest from the aeration pipes at the base. It was further hypothesised that the lack of oxidants (oxygen, ferric iron) and the likely inactivity of bacteria in these areas limited the re-dissolution of such secondary copper precipitates. In this study the above hypothesis was tested in column experiments using the same mixed sulfide ore and a synthetic leach solution. One set of columns was aerated and another set was operated without aeration. Results showed that precipitation of copper occurred regardless of whether the column was aerated or not. The results suggested that pH of the leach solution played a significant part in the precipitation of the copper. Further column tests revealed this to be the case. These results are described here in detail.

Jan 1, 2004

By G Lane, S Morrell

The design of the 12 m diameter SAG mill installed at the Cadia Hill Mine in New South Wales followed after two years of extensive laboratory and pilot plant testwork. The testwork showed the Cadia ores to be hard and competent necessitating the use of both a variable speed SAG mill drive and pebble crushing. The grinding power requirements for the SAG mill was based on engineering in-house grinding software, pilot plant data and simulations using JK SimMet software. Surveys of the SAG mill operation during the first four weeks showed the feed size distribution, transfer size and pebble rate to be lower or less than those for which it was designed. To compensate for the lower pebble rate, the SAG ball load was increased. This resulted in the total comminution circuit power being some 0.5 kWh/t higher than predicted. The JK SimMet SAG model has been modified to take account of these variations.

Jan 1, 2000

By D C. McPhail, S L. Rogers, J Brugger

Using iron- and sulfur-oxidising bacteria to catalyse the breakdown of sulfides that host the gold is an important biological method for the pretreatment of refractory gold ores. Following this biological treatment a combination of chemical and physical methods are used for leaching (such as the cyanide process) and concentration (such as carbon-in-pulp or electrowinning) of gold. Although these methods are well accepted by industry, they harbour limitations in the processing of low-grade refractory ores, and regulatory agency/public acceptance of cyanide use. Thus, it is beneficial to industry to develop environmentally friendly, cost-efficient leaching and concentration techniques that are based on micro-organisms. This may soon be possible by adapting the results of recent regolith geoscience research, which has shown that micro- organisms are capable of driving a biogeochemical cycle of gold dispersion, transport and reconcentration in the supergene environment. The indigenous microbiota in biologically active soil microcosms from a number of Australian sites are capable of solubilising up to 80 wt per cent of the gold contained in these materials during 50 days of incubation. Studies using molecular microbial techniques have shown that a metallophilic bacterium, Ralstonia metallidurans, is present in biofilms on gold grains from a number of Australian sites. R metallidurans is capable of actively accumulating gold from solution, suggesting that the bacterium may contribute to the formation of secondary gold grains and nuggets. Identifying the biochemical and physiological pathways that lead to the dispersion and accumulation of gold in regolith, and quantifying the reaction kinetics of these processes may thus lead to the development of industrial bio-processing capacities for gold-containing ores.

Jan 1, 2007

Coal exports are forecast to grow strongly, so that coal is likely to remain very important to Australia for the foreseeable future. However there is no sign that prices or profitability will rise of their own accord. Therefore the intense squeeze on costs will continue for the foreseeable future. This will mean lower manning, more outsourcing and probably an increasing rate of company attrition. As well, the political pressure from the greenhouse debate is only going to intensify and the pressure on the Federal Government after Kyoto is likely to be irresistible.

Jan 1, 1998

An intensely sheared and mineralized zone occurs in the quartz dolerite greenstone (or younger greenstone) mass on the western limb of the Kalgoorlie syncline. This zone comprises the western part of the Golden Mile and has produced the greater part of the 33,000,000 oz of gold produced to date from the main mining belts. A study of the general geological and structural features suggests that the lode shear system will continue southward on a pitch similar to that of the main syncline. Although payable ore has been found recently further to the south, the expectation of large quantities extending southward from the present mining areas is problematical.INTRODUCTIONUntil the late 1930's the principal mining activities in the western lode system were centred on three major ore-shoots formed on the No. 4, No. 3 and to a lesser extent on the No. 2 lode shears (Fig. 1). With the gradual reduction of grade in depth on these main ore shoots, increasing attention was paid to the "Minor Lode" system of lode shears known to exist in the same area. A large quantity of payable ore was found on these "Minor Lodes" particularly in the central part of the mining area. In recent years more attention has been given to exploration in a southerly direction.ROCK TYPES AND STRUCTURESThe western system occurs on the western flank of a dragfolded, south pitching syncline. The rock succession consists of Black Flag sediments overlying the younger greenstone horizon which overlies the fine grained older greenstone horizon. The axis of the syncline is regarded as a tight infold of the overlying Black Flag sediments. This infold has been faulted and intruded by albite porphyry resulting in the formation of a composite body of slates...

Jan 1, 1964

The widely accepted concept of mineral resources are that they are finite - mining therefore being intrinsically unsustainable. Yet the modern global mining industry continues to grow production at strong rates - how can this be? In reality, mining is a complex industry, starting with exploration, development, operations and then rehabilitation and closure. A recent major study of Australia has shown that for most mineral commodities, exploration continues to find new deposits, or expand resources at existing mines. In parallel, however, there are a number of key 'mega-trends' which are growing in their importance - declining ore grades (or quality), increasing tailings and waste rock volumes, the need for deeper mining, more refractory ore types, increasing energy inputs and higher unit energy costs, increasing pollution issues and, of course, not to forget greenhouse gas emissions issues. This paper will present a detailed case study of the ultimate sustainability of the Australian mining industry - showing long term historical data sets on ore grades, waste volumes and economic resources and placing these trends in light of major twenty-first century issues such as energy supplies (especially Peak Oil), climate change and existing and emerging land use conflicts (eg agriculture versus mining). Australia is a critical case study in the sustainability of mining, as it is a major global exporter of numerous commodities, and this is expected to continue to underpin the ongoing industrialisation of countries such as China and India. The ultimate question begs - can Australia actually meet this fundamental challenge, or will our resources run out, or will we be constrained by environmental issues such as climate change, land use or perhaps water? Rather than a mere optimist's or pessimist's view, this paper will present a range of hard data which underpins the debate about the sustainability of mining this century: ultimately, we cannot assume that the patterns of past mining will continue to work in the future. The sustainability of mining continues to hang in a precarious balance.

Jun 1, 2010

By A Tinnelly

Land disturbed by alluvial gold mining should be restored to a capability or productivity as good as that which existed prior to disturbance.   Effective rehabilitation requires detailed planning prior to mining and must also be closely integrated with the mining operations.   The main constituents of a rehabilitation plan: description of existing site conditions, choice of final land use, establishment of final landform, water management and erosion control, soil reconstruction, revegetation and management of rehabilitated land are briefly described.

Jan 1, 1989

By S L. Barbour

Measurement of the net percolation from the base of a cover system into the underlying waste material is a key component of a cover system monitoring program. The units of measure (ie a percentage of precipitation or rainfall) are simple to understand for all stakeholders, which increases the importance of obtaining representative net percolation values. In general, lysimeters are used to measure net percolation across the cover material-waste material interface; however, the design of lysimeters for cover system monitoring programs in the mining industry have typically not considered fundamental aspects of lysimeter design. Lysimeter design is typically thought of as being conceptually simple, when in reality the design, installation, and operation of lysimeters is often counter-intuitive, due to the complexities of flow through unsaturated soil systems. This paper puts forward a methodology for lysimeter design while also presenting the fundamental design variables that should be considered. Lysimeter design for differing climates, cover materials, and waste materials is discussed. Finally, the performance of lysimeter designs previously installed in the field at sites in Australia, Canada, and the United States are subjected to numerical modelling to determine whether net percolation is being measured properly.

Jan 1, 2003

Most of the world' s continental' shelves are .primarily . esozoic-Tertiary phexicmena. Those ,of south,eap- ern Australia are' no exception, although cam-plicated by possible TTmelon-seed" type block upthrusts in the region of the Bass Strait (e.g. King Island, Wilson's Promontory etc.) These terraces represent the progressive infilling and seaward. outgrowth of enormous volumes of tern g_enous sediments into the marine environment. Asa consequence they constitute the preferred habitats, of, petroleum.The Gambier ,sub-basin forms part of the southern Australian-continental terrace where it opposes the (3000 fathom), Jeffrey deep. The'purpose of'this paper is to discuss its nature, structure,_ and developmental history in re-lation to its oil prospects.

Jan 1, 1962

By J L. Mauk

Golden Cross is a volcanic-hosted, low-sulfidation, epithermal Au-Ag deposit in the Hauraki Goldfield. Irrespective of the rock type (andesite versus dacite), hydrothermally altered wallrocks are enriched in K, Rb, As and Sb around Au-Ag mineralised veins of the Empire vein system and stockwork. Sodium and Sr are strongly depleted around these veins, whereas Mg and Fe are locally depleted. Calcium and Si display mixed behaviour, varying from unchanged to depleted to enriched. Other elements including Al, Ti, Mn, Zr, Y, and Nb show little change or are immobile during hydrothermal alteration. Element enrichment and depletion trends are directly related to the degree of alteration and the alteration mineralogy. Addition of K and Rb and converse loss of Na and Sr in intensely altered wallrock surrounding veins corresponds to the replacement of igneous plagioclase by hydrothermal adularia. Sodium and Sr occur in moderately altered rocks on the margins or in æhard barsÆ that contain plagioclase. Locally, elevated Si concentrations and depletion of Mg adjacent to the Empire vein system reflects intense silicification of the wallrocks and the replacement of mafic minerals by quartz rather than by chlorite. The geochemical zonation patterns at Golden Cross are very similar to those at the McLaughlin deposit California, and shallow levels of the active Broadlands Ohaaki geothermal system. Therefore, determination of K, Na, Rb, Sr, and Ca enrichment and depletion patterns provides insight into alteration intensity and mineralogy that is complimentary to traditional trace element analysis of As, Sb, Hg, Au, Ag, Zn, and Pb used in the exploration of shallow level (< 500 m) epithermal Au-Ag deposits.

Jan 1, 2000

Hydraulic backfill is generally retained in stopes using permeable barricades. Mitchell et al (1975), Mitchell (1992) and Grice (1989) have shown that under normal drainage conditions, barricades experience low levels of loading. Cowling et al (1988) have also shown that barricades are susceptible to piping failures if excess water has ponded on the upper backfill surface and if leakage of backfill from the barricades has occurred. During 1997, six hydraulic backfill barricades failed in four different Australian mines. Fortunately, in each case, the quantity of backfill slurry released was small, and no injuries to personnel nor damage occurred. Detailed investigation of two of the incidents showed that the primary cause of failure could be attributed to the delivery of excess quantities of transport water from the low-density slurry. For each of the incidents investigated there was evidence of the development of piping failures, which resulted in hydrostatic loading conditions on the barricades from the ponded water on the upper backfill surface. The circular failure surfaces in the barricades were characteristic of the application of point loading conditions. This paper discusses the circumstances that led to these incidents and analyses the modes of failure. The standards for the safe operating of hydraulic backfill systems are reviewed along with requirements for ongoing management and control. The design requirements of barricade construction are analysed and some appropriate guidelines introduced.

Jan 1, 1998

Because of the coincidental location of orebodies and population in Australia, the mineral sands industry has been subjected to numerous land use conflicts, resulting in the sterilisation of strategic ore reserves and a severe downturn of activity in the eastern states. All tiers of government of various political persuasions were responsible for the decisions leading to this sterilisation. As such, it became a community response to intense land use pressure along an attractive and popular coastline. The resultant high public exposure of the industry has placed it in the forefront of developments in rehabilitation technology. In eastern Australia, the industry has operated in a wide range of ecosystems, many with conservation values. Rehabilitation ech- niques have been developed to suit these varied conditions, and much of this technology is now widely adopted throughout the mining industry. Land use considerations in Western Australia are somewhat different to those of the eastern states. Nevertheless, the same basic principles of rehabilitation apply with modification to suit local conditions and land use objectives. The development of rehabilitation in both Eastern and Western Australia is reviewed, and the direction of future trends is indicated.

Jan 1, 1986

The excavation of sandstone of generally medium strength for the Liverpool Link Line by Dosco Mark 2A Roadheaders has demonstrated the versatility and good performance of road- headers in suitable rock formations. A description is given of the strata traversed by the tunnels together with descriptions of equipment and crews, excavation sequences, operating difficulties and the results achiev- ed. In addition tunnel construction is des- cribed for a difficult section where there was only O.Sm clearance between invert and a four lane vehicular tunnel below, and O.5m clearance between tunnel crown and a century old sewer above.

Jan 1, 1976

Most publicity about the copper industry nowa- days is focused on the adequacy of ore reserves and on excessive mining capacity. These concerns, stemming from public awareness of actual and poten- tial shortages and oversupplies, relate to production rather than consumption. Perhaps the reason for this one-sided view is that copper is thought of as a commodity which is conspicuously traded in world markets, rather than as one of many industrial materials that serve today's rapidly changing tech- nology. Copper differs from other widely traded com- modities in that its real cost of production has pro- gressively increased since World War II. The reasons for the increase are identifiable by analyzing operations in one of the world's large producing centres, the copper province of Arizona. Another respect in which copper differs from some other com- modities is that increases in demand occur less auto- matically in the case of copper than they tend to in commodities whose consumption is more directly related to population growth. The copper industry's current inability to generate and attract needed investment capital is attributable to these differences between copper and other com- modities; it suggests that the concept of copper purely as a commodity is outdated. The key to the problem is better integration between the activities of copper producers and users. Depending on cir- cumstances, integration takes various forms- for example, investment tied to long-term sales con- tracts between producers in developing countries and consumers overseas; common ownership of pro- ducing and manufacturing facilities in industrialized

Jan 1, 1978

By M Laxman, A Kundu

After multiple tailings dam failures in recent times, the owner organisations have made increased efforts to step up the governance systems to industry best practise in the design, construction and operational management areas. The measures include but are not limited to, site investigation, rigorous peer review (both internal and external), certification through appropriately qualified personnel and improvement in operational management practises. While a lot of focus is on design and operational practices, the construction stage requires adaptation (both in terms of materials and approved design) and immediate decision making on site. Work undertaken in these areas is mostly irreversible and sometimes poses serious threat to the future TSF raise/ expansion planning and may lead to reduced life of the TSF and additional risk to the Owner.This technical paper will discuss some challenges and highlight the importance of appropriate processes to achieve a successful construction regime. The process will include a robust quality control/ quality assurance process, a team of designer-constructor-owner with suitable skills and technical understandings and robust documentation of the entire construction process from day 1 to the completion of construction.CITATION:Kundu, A and Laxman, M, 2018. Robust construction and quality assurance culture for tailings storage facilities – equally important as robust design and review practice, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 111–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

Selection of mining methods, stope dimensions and stoping sequences is usually based on comparisons with other similar orebodies or rocktypes. Rock mechanics principles assist the process, which can be further improved by application of rock mechanics' models - in particular, computer based stress analysis techniques. These models vary in capabilities and potential application but, basically, can be subdivided into techniques which only model the surface of excavations, and those which model the total volume to be analysed. To address the wide range of geometries, stoping methods and sequences, and geomechanical environments at Mount Isa Mines, a number of models have been developed. By presenting examples of their actual and potential application it is demonstrated that appropriate use of these techniques will assist in the determination of mining parameters and improve ore recovery. Examples presented cover sequencing in tabular and massive orebodies, location of shafts and shaft pillars, and backfill and hanging-wall stability. It is concluded that surface techniques are more appropriate for regional analyses and volume techniques are more suited to analyses of detailed, local geometry. Colour computer graphics should be an integral part of data preparation, and results interpretation and Presentation.

Jan 1, 1986

By T DePetris, B B. Beamish

There has been a gradual increase in the volume of internationally traded thermal and coking coal, with emphasis on blending of coals rather than single coal usage. New Zealand can take advantage of this situation, especially with its low ash and sulphur content coals. However, there is a need to clarify the thermal and coking behaviour of these coals as they relate to other market players, to benefit both the consumer and supplier. The high volatile matter contents of New Zealand coking coals are due to their high vitrinite content, which causes them to demonstrate stronger coking properties over a wider rank range than Gondwana coals. These same high vitrinite levels appear to correspond with lower initial softening temperatures than for Gondwana coals of similar rank. Preliminary results using thermogravimetric analysis also suggest that New Zealand high volatile bituminous coals can be used to substitute for higher rank Gondwana coals in combustion processes.

Jan 1, 1994

Although forty-seven years have passed since the by-product coke oven made its successful commercial appearance, it is only during the past fifteen or twenty years that this system of coal carbonisation has advanced rapidly to its present position ofabsolute supremacy.Early designs of by-product ovens proved more or less faulty, and the coke produced was so inferior to coke made in beehive ovens that there was a natural hesitancy on the part of coke producers to invest large sums of money in installations of by-productovens of doubtful utility-more especially in view of the fact that beehive ovens could be erected cheaply and operated by non technical labour for the production of high-grade coke under the most variable conditions of trade.Surely and steadily designers brought forward by-product ovens of improved type, coupled with more efficient apparatus for the recovery of by-products, but still the industry lagged, due almost entirely to the insistence on the part of coke users that the qualityof ordinary beehive coke was vastly superior for metallurgical operations to the best coke produced from by-product ovens. So deep rooted was this prejudice that only the passage of time could eradicate it. That it has successfully done so is strikingly illustratedin the following statistics:

Jan 1, 1928

By R Robinson

Modem occupational health practice can be described as the fitting of work to the individual and each individual to his job; perhaps a non-traditional way to view occupational health. This two-component description is achieved through the development of programs to implement and monitor specific job procedures, from the monitoring of unwanted exposures to contaminants to the auditing of mine sites. This paper is about such programs. Some attempt must be made to evaluate the effectiveness of the program and several performance indicators which are intended to measure the effectiveness of such a program are offered.

Jan 1, 1994