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The B.R.G.M., through international experience gained over many years, has become very skilled in alluvial prospection, particularly for diamonds. The research laboratories within the B.R.G.M. have also been active in creating new mineral processing equipment,. some of which is directly applicable to such prospection. One such development, the mobile prospection unit, is described and -its application in mineral exploration is demonstrated by a consider- ation of the diamond search in Australia and the general exploration of the Massif Armoricain (France). Because this latter study was fundamental in the development of the concept of "mineral-geochemistry", and its application in mineral exploration, it is also briefly described.

Jan 1, 1980

Multi Torque Industries and Jadefoil have developed a safer, more efficient method of explosive protection, retention, placement, and constraint. In particular, this refers to advancements in airbag technology, where the system will offer an alternative to conventional gasbags and decking methods to provide a far more controlled and safer working environment. Airbags have provided operator control and reliability which has not until now been possible in this type of application. The benefits have been noted by current users and the advantages have provided an increase in productivity and significant savings in explosive waste. Obvious problems with gasbags lie in their instability in hot conditions where the danger is associated with gas canisters exploding with great force posing a significant risk to operators. Other problems associated with the decking systems currently on offer is the lack of versatility and operator control. The airbag systems give the operator full control to guarantee accurate placement, assured retention whilst boasting a quick operation of less than a few seconds for conventional void blocking, decking and plugging. One of the main advantages of the airbags is that the operator has full control over placement and retention force, therefore in wetter conditions where slippage can be a problem extra air can be added at the operatorÆs discretion to ensure a sufficient grip. Technical calculations coupled with experimental testing have demonstrated that an airbag will support the weight of a 30 m water column in an 89 mm hole at an initial bag pressure of 5 psig. Applications are increasingly growing whilst more customers embrace their use. Advancements such as the ability to deck in overhead holes, block voids in overhead holes at any depth, explosive retention in very wet conditions, longhole stabilisers to prevent hole closure and concertinaed liners reflect a dynamic potential for new technologies. All of these applications provide a decrease in explosive waste, an increase in operator safety, an increase in explosive protection, and an increase in productivity.

Jan 1, 2004

Many of the large refrigeration plants used in, the cooling systems on deep South African gold mines are situated on surface where they are exposed to seasonally and diurnally varying climatic conditions, and to a diurnally varying demand for cooling made by the mine. It has been traditional to accommodate the seasonal variation in climate by manual control applied to the plants at appropriate times of the year, and the plants have normally been specified to conform passively to the diurnal variations. This paper introduces new strategies for the active automatic control of the plants on a diurnal cycle, and shows that attractive benefits in energy and chilled water resource management can be accrued through the use of these strategies. The results have been derived through the modelling and simulation of a representative refrigeration plant.

Jan 1, 1985

The information age has arrived. In every aspect of life, at the end of the second millennium, computers and information technology have made significant inroads. In mining there has been huge growth in the use of digitally controlled systems. From resource evaluation to mine planning to daily operations, information is being acquired, analysed, modeled and presented, using state-of-the-art information technology. Explosives, too, have moved into the information age. Computer controlled trucks and manufacturing plants have been developed and are now a regular feature on many mine benches. The next challenge for the explosives industry as a whole is to integrate blast initiation with information technology. The benefits are there, both to the supplier and to the end-user. Much has been written in the past about the potential for blast improvement but there are other significant advantages to a digital initiation system. These include security from unauthorised use, stock control and minimisation, reliability through testability and ease of use to name a few. So why is it taking so long? Surely the complexity of an electronic initiation system is far less than that of mobile phones that have been around for a long time. The answer, it seems, lies in the level of new technologies that need to be developed. There are enormous technological hurdles to be overcome in order to put into the market a cost-effective, reliable, user-friendly electronic initiation system. The most significant of these are:Safely and reliably initiating an explosive from an electronic device powered by a small capacitor. Prior to the development of electronic detonators primary initiation of explosives was by shock tube spit or by passing large currents and voltages down a pair of wires. Electronic detonators do not have that luxury. For example the energy stored in a æBeethovenÆ exploder is more than 500 times greater than that available to an electronic detonator. Communicating to a multitude of devices over very long cables installed by miners in harsh conditions. The deployment of an electronic detonator system has been likened to building a large telephone exchange in the rain and getting it to work perfectly first time! New communications protocols needed to be developed and tested. Wiring and connection systems have to be designed to survive the mining environment. In spite of these technological hurdles most of the major explosives manufacturers have persisted with electronic initiation systems and we are now, in 1999, starting to see the results of these multi-million dollar efforts. At SMI we are often asked many questions about this technology. The remainder of this paper seeks to answer those most often asked. As with any business linked to information technology todayÆs breaking news is tomorrowÆs archive and we expect the rate of development and understanding to accelerate as these technologies become accepted by the global mining industry.

Jan 1, 1999

The emerging discipline of ægeometallurgyÆ is not new but is becoming increasingly recognised as a discrete and high-value activity that reflects an ongoing commercial and cultural trend towards more effective mine site integration and optimisation. The AMIRA International P843 æGeMIIIÆ project (Geometallurgical Mapping and Mine Modelling) is a major new cross discipline research collaboration designed to provide support for this emerging industry trend. The project is currently supported by 18 global mineral companies and involves collaboration between the CODES Centre of Excellence (University of Tasmania), JKMRC and BRC (University of Queensland) and CSIRO Exploration and Mining. These groups represent recognised research excellence in the fields of economic geology, automated core logging, advanced microscopy and process mineralogy, mineral processing, mine planning and resource optimisation. The needs and challenges of geometallurgy as an integrated activity will be outlined together with the ongoing contribution and aims of the AMIRA P843 æGeMIIIÆ project. The main emphasis is on development of predictive geometallurgical indices for key processing performance parameters that reflect inherent geological variability. The ultimate aim is to provide predictive indices of geometallurgical performance that can be confidently embedded into resource models and used for risk-defined mine planning and optimisation.

Jan 1, 2008

By S Brunt

A new elution process has been developed for the recovery of gold thiosulfate from ion exchange resins. This is a synergistic system which utilises a base eluent, such as nitrate or trithionate, along with an additive that improves the elution of gold. The use of the additive enables lower eluent concentrations to be adopted, as well as weaker eluents such as chloride. With the chloride + additive system, complete gold elution can be achieved within 12 BV when utilising an eluent flow of 5 BV/h. When the eluent flow is reduced to 2 BV/h, complete elution is achieved within 8 BV. Similar results are obtained when using nitrate or trithionate as the base eluent. A copper pre-elution process has also been developed, whereby the majority of copper can be stripped within 5 BV prior to gold elution. This method is a significant improvement on the ammonia + oxygen pre-elution previously suggested. The development of a new analytical procedure based on ion chromatography with UV detection is also described for the quantification of polythionates in leach solutions and loaded on resins. This enables analysis to be carried out for resin-in- leach type processes where the polythionates are being formed in solution and simultaneously adsorbed onto the resin.

Jan 1, 2007

Full aerodynamic design development of the proposed fans for the enlarged primary ventilation system at Mount Isa Mines Limited was initiated before tender specifications were prepared. Theoretical and analytical design studies were made of many possibilities to determine the optimum proposal. Major considerations were efficiency, simplicity, standardization, and mechanical feasibility. Model testing and experimental work covered blading design, inlet shape, diffuser and tail fairing dimensions, instrumentation requirements, ancl noise studies.Theoretical and predicted performance estimates were prepared for the three 20 ft diameter vertically mounted axial flow fans.

Jan 1, 1967

By C Nucifora, M Landers, J Jones, G Maddocks, K Mandaran, A Forbes, W Wilson, S Newman

Glencore’s Mount Isa Mines Limited (MIM) operates the Mount Isa open cut and underground copper (Cu) and zinc-lead (Zn/Pb) mines near Mount Isa in Queensland, Australia. Tailings from processed Cu and Zn-Pb ore is contained in a 1,315 ha shallow (< 35 m deep) multi-cell valley fill tailings storage facility (TSF). Static geochemical testing conducted by MIM over the life of mine (LoM) verifies that the Cu, and Zn-Pb tailings has a wide range in sulfide content and diverse mineralogy with significant acid neutralising capacity (ANC) in some samples. The tailings are predominantly classified as potentially acid forming (PAF) using static analytical methods. Kinetic leach testing using free draining columns and humidity cell tests simulating tailings placed on the surface of the TSF suggest that the tailings samples are likely to remain non-acid forming (NAF) for 10 to 40 years under aerial exposure, and much longer than this under saturated conditions within the TSF. During this period of weathering, as ANC is depleted, the neutral pH drainage may contain elevated concentrations of some elements including sulfate, manganese and zinc. Only when the ANC is depleted would the tailings then begin to produce acid drainage. CITATION:Mandaran, K, Jones, J, Nucifora, C, Maddocks, G, Landers, M, Forbes, A, Wilson, W and Newman, S, 2018. Mount Isa Mines Rehabilitation Materials Sampling and Analysis program for closure planning, in Proceedings Life-of-Mine 2018, pp 138–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Moore A. J

Blasting in mines in an urban environment can be conducted safely and within regulatory vibration limits by careful attention to detail and the application of correct techniques. Factors affecting blast vibration are described using surface and underground mining examples. An understanding of these factors provides an essential base for effective planning and operational control. Techniques are described for assessing and predicting vibration levels and the presentation of data for planning purposes such as environmental impact statements for new projects and the protection of buffer zones around existing operations.

Jan 1, 1997

Powercoal Pty Ltd operates eight underground coal mines in New South Wales and produces coal for both domestic power stations and the export market. Approximately 40% of total production is from continuous miners. Over the past five years, place change mining methods have been introduced to improve productivity from continuous miners. This has involved utilising the existing coal clearance system from the continuous miner to the ratio feeder using trailing cable shuttle cars.By late 1996 average productivity at Cooranbong Colliery using this system had plateaued at 800 tonnes per eight hour shift. A number of factors were identified to increase average productivity to 1500 tonnes per eight hour shift. An improved coal clearance system was one of the factors identified.

Jan 1, 1998

By M T Roche

The Cannington deposit is one of the largest accumulations of silver-lead known. Located 135 km southeast of Cloncurry in North West Queensland (Figure 1), Australia, the deposit is currently in the feasibility stage of its development. The deposit is named after the nearby Cannington Pastoral Property which runs some 25 000 sheep on 'downs' country. The investigations of the Cannington deposit are carried out under the authority of Mineral Development Licences 139 and 144 and Exploration Permit for Minerals 6788, Answer Downs. Exploration for Broken Hill Type (BHT) silver-lead-zinc deposits in the Mt Isa region has been undertaken by The Broken Hill Proprietary Company Limited's Minerals Division (BHPM) since the early 1980s following in-house research which showed that the Eastern Succession of the Mt Isa Block exhibits characteristics which were favourable for hosting BHT

Jan 1, 1994

The Palaeozoic succession of Victoria contains one of the world's major gold provinces with a total production of 2500 tonnes of gold. Larger deposits, including Bendigo (over 800 tonnes Au), are related to Ordovician slates and greywackes, but a wide range of metamorphosed sedimentary and igneous rock types are host to significant gold deposits. Most, if not all, deposits demonstrate structural control, although the controlling structural features are variable between deposits: a majority of deposits comprise quartz veins. It is suggested here that a major factor in making Victoria such a gold-rich province might be a particularly high geothermal gradient in central Victoria during the Tabberabberan orogeny (360-380 my). This generated auriferous metamorphic fluids from underlying successions (?Cambrian) which migrated upwards along active structural pathways. One cause of gold deposition appears to have been fluid reduction by carbon, but other methods are suspected. This model is considerably simpler than the plethora of syngenetic, granite magmatic and lamprophyre-related models that have been proposed recently, but is in basic agreement with Cox et al. (1983). Exploration models for similar gold deposits both within Victoria and elsewhere should take account of the negligible evidence for a major syngenetic contribution to Victorian gold production, and the lack of any clear genetic relationship to particular igneous rock types. A real opportunity exists for new deposit types not identified by the early prospectors.

Jan 1, 1991

By Hinton A. T

Three, and possibly four, distinct types of quartz-vein associated gold mineralisation are recognised in New Zealand. They are: epithermal, schist-hosted, metagreywacke-hosted and metamorphic core complex associated types. Each has a unique geological environment and structural regime which has provided the gold source, scavenging mechanism, emplacing mechanism and geometry. Each has a characteristic suite of associated metals and trace elements. The first three types form economically important gold deposits while the fourth type have been historically worked for gold and base metals. Intense exploration is currently being focussed on all four types.The epithermal type is typified by the extensive vein systems of Martha Hill, Karangahake and Golden Cross and numerous smaller examples. The veins were deposited in a near surface active volcanic environment from deeply circulating hot water. Their structure is tensional, veins are vertical-to sub-vertical and have limited depth. Their geochemistry is identical to that in active felsic hydrothermal centres in the central North Island. Major minerals are gold, pyrite, arsenopyrite, galena, chalcopyrite, sphalerite and argentite.

Jan 1, 1990

By Cunningham DA

Plant based on the New Jersey refluxing process has been installed at the Cockle Creek Works of Sulphide Corporation Pty. Limited to refine portion of the zinc output from the Imperial Smelting Furnace. Refining of impure zinc is effected by distillation in two stages in vertical columns compris- ing a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage the volatile elements (zinc and cadmium) are distilled from impure metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content. The resultant zinc has a purity in excess of 99,995 per cent zinc. The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basis grades of zinc.

Jan 1, 1969

Over the past seven years, a combination of New Zealand-, Australian- and German-led research voyages using the research vessels Tangaroa, Southern Surveyor, and Sonne respectively, have revolutionised our understanding of the Kermadec-Tonga arc-backarc systems. This convergent margin is the most seismically-active subduction zone system on Earth with convergence rates steadily increasing northwards from the Hikurangi Trench to ~250 mm/year at northern Tonga. In combination with the intra-oceanic setting, factors potentially producing magmatic, tectonic, and hydrothermal variability in this system include an increase in potentially subductable sediment northwards along-strike, intersection of the Louisville Ridge (hot-spot chain) and Osbourn Trough (paleo-spreading centre) with the arc at ~25¦S, and the possibility of Samoan (hot-spot) plume ingression in the northern Lau Basin. The bulk of the magmatism is submarine; whereas only a few emergent (some transient) volcanic islands exist, about 80 submarine volcanic centres of significant size (>1000 m above surrounding sea floor) are present between White Island in the south to north of Tafahi in Tonga. About 35 per cent of these centres are hydrothermally active. Important petrogenetic features of the volcanic rocks along this arc system are the abundance of rhyolite (some quartz-amphibole-bearing), and the outcrop of primitive olivine-clinopyroxene-phyric basalts in satellite cones of the major edifices. Many of the edifices consist of complex caldera systems. Eruptions from and degradation of these edifices were probably tsunamigenic. Many of the hydrothermal systems developed within the edifices are likely destroyed during the sector collapses which are the characteristic edifice degradation mode. There are three backarc spreading systems along this margin: the Havre Trough, Valu Fa-Eastern Lau Spreading Centre, and the nascent Fonualei Rifts. The latter are particularly notable in having captured the entire suprasubduction zone magmatic flux for a distance of about 150 km, shutting down the adjacent volcanic front arc volcanoes.

Jan 1, 2005

As an indication of the overall quality for the three periods the expected run of mine ashes are given. Operating Period R.O.M. Quality Years 1 - 4 22.0% Ash (db) Years 5 - 14 18.8% Ash (db) Years 15 - 20 17.3% Ash (db) The size distribution of the coal was found to be generally as predicted in the 1980 study. However the ash, particularly in the smaller fractions, was found to be higher due to the previously mentioned friable nature of contaminant material. Following evaluation of this additional information, the proposed washery design was reconsidered. Three basic process schemes were examined. 1. A jig with two-stage heavy medium cyclones and spirals for treatment of three different size ranges. 2. A heavy medium vessel, two-stage heavy medium cyclones and spirals for the different size fractions. 3. A jig for initial treatment of the total feed (that is all sizes) with single-stage heavy medium cyclones and spirals for rewashing of the intermediate and smaller size Fractions.

Jan 1, 1986

A novel problem-solving exercise for undergraduates is described which is directly relevant to production supervision. It is based on the fictitious Metwin Plant which produces refined metal from sulphide concentrates via a hydrometallurgical route with six unit operat- ions. Students are given details of the chemistry, process engineering and normal operating conditions. They are also given min- imum data for the Plant when it is operating with a fault. By requesting further data, for which they are 'charged', the students must diagnose the fault. The responses of students to the exercise are described. The data were produced by computer simul- ation of steady state operation under normal and various faulty conditions. The development of this program was an educational experience for the author and it stimulated new interest in metallurgical process engineering.

Jan 1, 1984

The geotechnical factors controlling the design of the open pit slopes of the Pasminco Century Mine near Lawn Hill, Queensland are presented below. Pasminco Century is a stratiform shale hosted zinc deposit in the Lawn Hill Formation that is overlain in part by the Thorntonia Limestone Formation. Both the mineralisation and overburden is located within a competent rock mass such that intact rock strength and discontinuity spacing is generally sufficient to prevent large-scale slope failure by breakage through the rock mass. Rather, overall slope stability issues are dominated by the major discontinuities within the rock mass. The deposit is located in a structurally complex regime, it consists of a synclinal basin which is truncated by easterly striking normal faults through its centre and northern and southern limits and by an unconformity on its eastern and western margins. Deposit geometry and slope stability is further complicated by small-scale folding, a pattern of northeast and southeast striking subvertical faults and north easterly dipping thrust faults with their associated fault emplaced blocks of Lawn Hill Formation in the overburden. The large size of the deposit requires a staged mining approach with the excavation of both final pit walls around the external sides of each stage and interim pit walls along the internal boundaries between adjacent stages. The deposit geometry and major discontinuities control not only the final pit wall design but also interim wall location and orientation, excavation sequence and in some stages the excavation schedule. Two and three-dimensional limit equilibrium stability analyses were conducted using both deterministic and probabilistic approaches to determine appropriate pit wall design criteria and to select a suitable excavation sequence and schedule.

Jan 1, 2000

Mining had a very considerable effect on the country's development. The visual evidence remaining is an integral part of New Zealand history. Early mining for manganese and copper in the 1840s was succeeded by alluvial gold rushes. These gave way to hard rock extraction, hydraulic elevation and dredging. Coal mining dating from the 1850s was fairly widespread. Other minerals were obtained on a small scale. Manufacture of mining' machinery stimulated industrial engineering enterprises. Schools of mines played a significant part in advancing technical skills and several remain as museums. Surviving mine structures and site relics are part of the industrial heritage signifying the technological and economic development of a small isolated nation. Some of these are described. Identification, recording and preservation where practicable is advocated.

Jan 1, 1990

By M Fisher, P Bradley, D Rogers

New England Antimony Mines has operated the Hillgrove Gold Plant at Hillgrove in New South Wales since 1969, producing stibnite and arsenopyrite products by selective flotation. Gold is present in the ore as fine free gold, gold associated with stibnite and gold associated with arsenopyrite, with some ten to 20 per cent of the gold reporting to the antimony stream and 35 - 50 per cent reporting to the arsenopyrite stream. Opportunity to process the arsenopyrite concentrate for onsite recovery of the gold values to improve upon the ten per cent recovery achieved by conventional cyanidation was recognised and subject to comparison with biological oxidation, roasting, nitric acid oxidation, low temperature oxidation (Activox«) and conventional pressure oxidation. Following further testwork and a feasibility study, a 7500 tonnes per annum concentrate feed pressure oxidation autoclave circuit was constructed at Hillgrove and commissioned in October 1999. The plant has operated at the close to design capacity since commissioning whilst optimising various operational and metallurgical aspects. The last three years has seen the process achieve an overall gold recovery of greater than 90 per cent for oxidised concentrates.

Jan 1, 2002