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By Filigenzi M. T

Stresses around mine openings at depth can cause the surrounding rock to fail, releasing stored strain energy. When this happens, the rock may literally explode or `burst' into the opening without warning. As mining progresses deeper into the earth, the possibility of seismic events and rock bursts increases. Researchers at the US Bureau of Mines (USBM) are currently studying seismic activity in three underground hard-rock mines in the United States: the Homestake Mine, Lead, SD; the Lucky Friday Mine, Mullan, ID; and the Sunshine Mine, Kellogg, ID. Waveforms from seismic events are recorded by personal-computer-based hardware and software. This information is archived and transferred from the mine sites to the USBM via modem communication links. Then, using USBM-developed software, the events are analysed to determine various parameters, including magnitude, frequency, and location. In addition, researchers are modelling the deep levels of the Homestake Mine using a finite-element code. These models generate stress and displacement values for a given loading condition. By studying material properties, in situ stresses, and seismic activity along with actual scope sequencing, researchers can make correlations between stresses induced by mining and the frequency and magnitude of seismic events. Information on seismic events coupled with results from finite-element analyses have increased understanding of rock mass behavior and the mechanisms that may lead to rock bursts. Optimisation of slope sequencing designs as a result of these studies could reduce rock burst hazards.

Jan 1, 1995

By Hindmarsh G

The colliery is owned by the BHP Collieries Proprietary Ltd., the principal shareholders being the Broken Hill Pty. Company Ltd. and Hebburn Limited.It is situated due west of Newcastle and 6 south-east of Cessnock, N.S.W., and is conneeted by 36 miles of railway to the port of Neweastle. Of this mileage, 3 miles are owned by the Company, 3 by Hebburn Limited, 9 by the South Maitland Railways Ltd., and 21miles by the Government Railways.The seam worked is known as the Main Greta Seam of the Greta Coal Measures and is on the southern slope of the Lochinvar anticline.At the shaft, the seam is 1190 ft. below the surface, and the section of the coal measures is:-Upper or Main Seam, . 24 ft. 0 in.Conglomerate and shale 70 ft. 0 in.'Middle Seam 8 in.Conglomerate 25 ft. 0 in,Bottom Seam 1 ft. 2 in.These lie between two marine measures, and are the lower coal series of the permo-carboniferous period.Only the upper seam is workable in this area, the lower seams being too thin for eompetitive working. The section of the workable seam at the shafts is as shown on Fig. 1.Unfortunately, only the lower 12 ft. 5 in. of the seam is saleable.

Jan 1, 1935

In Australia, current production of rare earth element (REE) minerals, monazite and xenotime, occurs as by-product from titanium-enriched placers and beach sands. Undeveloped REE resources are associated with carbonatites, alkaline igneous rocks, pegmatites, phosphorites, cemented fluvial sandstones, and uranium mineralisations. The REE are held within a range of minerals including silicates, phosphates, a1uminophosphates, carbonates, and oxides. The development of these REE resources may require new processing and extraction methods. The distribution of REE in the currently mined ore minerals, monazite and bastnaesite, does not match that requested by the market. Exploration for new REE resources should be focused on ores with more marketable REE distributions, particularly with heavy REE, neodymium, samarium, europium and yttrium enrichments. Such ores occur within alkaline igneous rocks, in laterites overlying carbonatites and alkaline igneous rocks, and in placers derived from low-grade regional and contact metamorphic sediments. Lateritic REE deposits may be easily and economically mined by shovel in open pits and are unlikely to require extensive crushing and milling. In addition, lateritic REE clay deposits may be processed by simple hydrometallurgicaltreatment mehtods.

Jan 1, 1991

By E Forbes, G V. Franks

"This study investigates the dual function of a temperature responsive anionic co-polymer of poly (N-isopropyl acrylamide) (PNIPAM) as a selective flocculant/flotation collector. PNIPAM is used for separating hematite from 50:50 mixtures of hematite and quartz, at a variety of particle sizes. The performance of PNIPAM in this system is compared to that of conventional flotation collectors: sodium oleate and sodium dodecyl sulfate. The results of the study demonstrate that anionic PNIPAM used at 50¦C (above the lower critical solution temperature (LCST)) is the most effective flotation collector for hematite particles in the size range between 10 and 20 ¦m. This is attributed to the increased probability of both particle/bubble collision and particle/bubble attachment through the formation of hydrophobic hematite aggregates. Anionic PNIPAM used at 50¦C also produced the highest hematite recoveries for very fine hematite particles (circa 1 ¦m). However this recovery was completely unselective. This lack of selectivity is partially attributed to the activation of quartz particles by PNIPAM, but is thought to mainly occur as a result of entrapment of quartz particles within the matrix of hematite aggregates.CITATION:Forbes, E and Franks, G V, 2013. Selective separation of hematite from quartz by flotation using a temperature responsive polymer, in Proceedings Iron Ore 2013, pp 381-390 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By D Giles

We present plate tectonic reconstructions, showing that porphyry-type ore deposits are spatially and temporally linked to ridge subduction. A reconstruction of the Peruvian subduction system reveals an immediate metallogenic response to the arrival of the Nazca Ridge at the subduction trench, followed by southward migration of the zone of metallogenic activity due to the lateral migration of the zone of ridge subduction. A similar pattern is recognised in central Chile , where the spatio-temporal distribution of giant ore deposits coincides with the arrival of the Juan Fernandez hotspot chain at the subduction zone. We conclude that there is a spatial and temporal link between ridge subduction and ore deposit formation, with high metal fluxes concentrated in zones of ridge subduction. Thus, the recognition of tectonic patterns associated with ridge subduction can provide insights into predictive mineral discovery by enhancing our ability to predict the position of large mineral deposits in other modern and ancient orogens. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By G Billing a, D Gribble, E Hall, D Varga

The theoretical benefits of electronic detonators have been reasonably well documented. To support this, a practical comparison was made between the performance of the standard shock tube system, NONEL, and a high precision electronic system, HotShotÖ, at the Sunrise Dam Gold Mine. The expected benefits from electronic detonators to Sunrise Dam were identified prior to the trial. Based on these, a number of objectives were set to demonstrate the value of the HotShot system. These are an improvement in fragmentation leading to an increase in productivity, less oversize rehandling, increased throughput and more uniformity in muck pile movement. To maintain the integrity of the trial, the nominal timing of the shots was kept exactly the same, thereby restricting any performance improvements to the precision of the electronics. Accordingly, adjacent shots were chosen with consistent geology. Video footage was taken of the blasts and vibration monitoring was carried out by fixed geophones throughout the mine. Spot heights of the muck pile swell were taken immediately after the blast and heave profile graphs were generated for comparison. Video footage was taken for a period of three hours for both shots to analyse cycle times of the excavator and trucks. PITRAM data was also collected for analysis. As far as practicable, the ore was taken to the same finger on the run-of-mine (ROM) pad to assist in single sourcing for the crusher and to allow oversize to be separated out. From specific metrics taken during the trials, it was shown that the expected improvements due to the high precision timing of electronics were realised in all areas.

Jan 1, 2007

By Lindner E, Bosio M

South Australian coals are all low in rank and generally poor in quality, with difficult combustion characteristics. This circumstance makes the selection of a fuel source for future power generation difficult, requiring careful study and detailed analysis of the various alternatives. Combustion characteristics can have a significant effect on plant design and costs, and need early attention in any exploration and evaluation programme. The physical location of the deposits, often remote from established infrastructure and centres of population, is also a major factor in the ultimate cost of power at the poirl use.

Jan 1, 1977

The products of the steel tube industry play an important part in the production,' transrzission and refining of oil. Steel tube manufacturing is already well established in Australia and supplies the petroleum industry with its requirements" within the .present limitations of the various tube plants., With the discovery of oil in commercial quantities in this country, the steel tube industry could be expected to extend its scope to cover a much wider range; of oil country tubular goods, line pipe and refinery. Tubing.

Jan 1, 1962

By Richardson G. W, Yap L. C

Friction rock stabilisers (FRS) are the most common steel-based ground reinforcement used in underground mines in Western Australia. As with any other steel-based product used in underground mines they are susceptible to corrosion, particularly under aggressive minewater and mineral conditions. Because of their thin-wall tubular construction and large surface area, the potential damage resulting from corrosion is considered to be more severe for this type of reinforcement than for other forms of reinforcement made of solid steel bars. Because of the obvious safety problems which may result from corrosion, both mine operators and regulators have raised concerns regarding the long-term effectiveness of FRS installed in underground mines in Western Australia. Although corrosion has been recognised as an important safety issue, the controls of corrosion in varied underground mining environments has not been well understood. To improve the understanding of the corrosion behaviour of FRS, the Department of Minerals and Energy has initiated a research project focused on the mechanisms and extent of corrosion attacks, and their influence on the effectiveness of the reinforcement. This paper describes the research project and presents the interim results achieved To-date.

Jan 1, 1995

By Amelunxen R, Finch JA

Flotation columns represent an important addition to flotation practice. Columns have largely replaced. conventional machines in molybdenum cleaning in Canada. Columns have been successfully tested on bulk copper/molybdenum cleaning at Gibraltar Mines Ltd. A rougher cleaner/scavenger cleanercombination was shown to be capable of giving higher grades and recoveries compared with three stages of conventional cleaning. A control strategy for the columns has been developed. An interaction between gas hgldup and wash water rate has been exploited to control performance.

Jan 1, 1985

By Thimons E. D, Derick R. L

In early June, 1986, a fire of unknown origin erupted in one of several main entries of a coal mine located in southwestern Colorado. The fire was aggressively fought with high-expansion foam. As a result of several strategic decisions, the fire appeared to be held in-check. Unfortunately, sufficient quantities of foam were unavailable and as soon as the foam was depleted, control of the fire was lost. To prevent further damage and the possibility of an explosion, all entries to the mine were sealed.

Jan 1, 1988

The long continuing controversy over the Origin of fusain, whether it is a product of primeval forest fires, or of special conditions of weathering (including bacterial decay) of the vegetal debris concerned prior to, burial, has now been extended, to include the possibility that fusain is a product of the coalifaction process subsequent to deposition, so that doubt may reach even to its time of formation.The conflicting views on this point are summarised in the following quotations from two recent publications (my italics in each quotation):1. "Recent observations made in peat and brown coal deposits in Australia, England and Germany strongly suggest that practically all fusain is formed by coalifaction after deposition and 'preliminary compression. In deposits of advanced brown coal rank, it normally takes the shape of pieces of wood compressed parallel to the bedding plane; and some fragments consisting partly of fusain and partly of vitrain exhibit the same amount of compression throughout. This would seem to indicate fusinisation after burial, as hard brittle charcoal would be crushed, or else retain its original irregular shape if strong enough to withstand pressure.In some immature deposits, however, where cover is of a hydrostatic nature rather than a vertical compressionar force, occasional pieces of fusinised wood showing very little flattening are present, but such immature deposits seldom contain the proportion of fusain found in higher rank coals. In view of this, and the possibility of introduction of charcoal into peat deposits, it is felt that a small amount of the fusain in coal may represent wood charred before burial, but most of it almost certaInly originated as a product of fusinisation after burial" (Dulhunty, 1948, p.14).

Jan 1, 1953

By J Moncrieff, P Bellairs

The Black Star Open Cut is located immediately adjacent to the township of Mt Isa and is situated in the middle of extensive pre-existing infrastructure including two concentrators, two smelters, a wet fill plant and two shafts. At any one time there are in excess of 500 people working on the surface within an industry-accepted 600 m exclusion zone from Black Star blasts. Apart from the surface operations there are also the underground operations including the lead mine (closed in December 2005) and the Enterprise and X-41 mines that must clear for all Black Star blasts. The application of industry standard blasting exclusion zones (600 m) was risk assessed as imposing operationally prohibitive constraints which could cause significant business interruption due to the logistical challenges required to ensure that all personnel from surface plants were evacuated for each blast and potential for lost production whilst these personnel were not operating the plant. In was therefore an imperative for the blast exclusion zone to be reduced. This was achieved by the: use of a QA/QC team to ensure that relevant drill and blast implementation is within an acceptable tolerance (KPIs) from design; use of high-quality stemming material called HMR, which is a by- product of the concentrating process and is generally sized at -14 mm with very little fines; implementation of appropriate training and support to Black StarÆs own blast crews, reinforcing the need to achieve the designed amount of stemming in every hole; and provision of appropriate support from Black StarÆs management for additional resources to ensure that every blast achieves design within the KPIs but especially in high-risk areas. The blast exclusion zone was successfully reduced after monitoring the flyrock results from more than 176 blasts. Black Star Open Cut now maintains a minimum blast exclusion of 200 m in critical areas; however, general blasting currently uses a 250 m exclusion as this provides additional risk management whilst still minimising the logistics associated with clearing and securing the slightly increased area.

Jan 1, 2007

By Watsford R. M S, Hutton R

Following the delineation of significant extra ore reserves during 1990, the decision was made to expand production from 350,000 tonnes of run of mine ore per year to initially 600,000 tonnes increasing to 750,000 tonnes per year. The existing plant consists of a conventional three stage crushing plant followed by a heavy medium separation plant that produces a product prior to grinding. Grinding is conducted in three stages of ball mill in series. Alternatives examined for expanding production included: aò SAG mill - ball mill circuit replacing the secondary and tertiary stages of crushing, the heavy medium plant and the existing ball mills; and, upgrading of the existing circuit configuration.

Jan 1, 1991

By Valenta R. K

Copper-gold deposits associated with iron oxide rich rocks (ironstones) form a distinctive and significant ore association which occurs widely, but not exclusively, in the Proterozoic. The ironstone association is geochemically distinct from the BIF-hosted gold association (Phillips and Groves, 1983). Not only is the former association higher in its copper and commonly uranium, FEE, ¦bismuth, molybdenum contents, but also the ironstones in many cases do not originate as chemical sediments. Although both associations form in metamorphic environs, they reflect differing tectonostratigraphic settings and with consequent differences in ore-forming fluids and ore-forming mechanisms. This paper discusses the nature and origin of the ironstone-related copper-gold association, with particular reference to the Tennant Creek district in northern Australia, and emphasises the two stage origin of mineralisation. The genetic model developed has significant implications for other ore-bearing environments.

Jan 1, 1990

By R Ashworth, S J. Hall

During trials which began in May 2005, traditional steel dump bodies for transporting iron ore on 220-tonne haul trucks at a Labrador iron ore mine were compared to a novel rubber suspended dump body. Loads were measured and compared over some 93 700 loads, representing more than 20 Mt transported. Maintenance costs and downtime were also measured over the course of the trial, which lasted nearly one year. This paper outlines the parameters and results of the trials. Parameters measured included payload and production improvements, carry-back reduction, downtime due to body maintenance, and wear on the floor of the suspended dump body. These parameters were then compared to those for conventional steel dump bodies in use at the mine, and conclusions were drawn. The resulting comparisons were significantly positive in favour of the new suspended dump bodies, confirming that each truck could haul an additional 41 000 tonnes per year, that downtime hours could be considerably reduced, and that body availability and service life can be extended through use of the suspended dump body. There was also a high level of operator acceptance of the suspended dump bodies due to less loading shock and a smoother ride.

Jan 1, 2007

When Matthew Flinders entered in his log `This land forms the South side of the large bight; and besides projecting beyond the coast line, and being a little higher than usual is remarkable for having some reddish cliffs in it, and deep water near the shore', he was commenting on the deposit of bauxite at a place now known as Weipa. This sighting took place on 9 November 1802, and probably represents the first direct entry in Australia acknowledging a potential mineral deposit. Flinders, of course, had no idea as to what he was looking at, nor did he land to determine its content. If he had, he probably would have had no idea of the substance, and even less knowledge of its use. Nothing further was done to this for about 150 years.

Jan 1, 1993

The object of this paper is to show in some detail the mining challenges that have been presented and overcome during the successful development of the main exhaust ventilation drive that will service the Ballarat East mine during its 20+ year lifespan. Topics to be discussed in this paper include the ground support regimes employed, the ground conditions encountered during construction, how the heading was recovered after falls of ground and the effectiveness of geotechnical probe drilling at Ballarat.

Jan 1, 2006

By Oxenford R. J

An important rutile-ilmenite-zircon bearing sand deposit was discovered by local farmers at Eneabba, 300 km by road north of Perth in 1970. These heavy minerals occur in a series of ancient strandlines and associated dunal deposits at elevations from 85 m to 170 m above the present sea level and are situated,30 km inland. The strandlines were deposited on wave- cut platforms in an ancient bay bounded by Mesozoic sediments during a series of regress- ions from a high sea level, probably during late Tertiary or early Pleistocene times. The immediate source of the heavy minerals in the Eneabba deposit is a widespread low content of those minerals in the nearby Mesozoic sedi- ments. The high-grade southern portion of the Eneabba deposit has been closely drilled and is now being prepared for production by Allied Eneabba.Pty. Ltd., a subsidiary of Allied Minerals N.L. This part of the deposit is 11 km long and up to 2.5 km wide. It is characterised by little or no overburden and the average depth of mineralisation, bounded by a 2.5 per cent heavy mineral cut-off, is 12 m. The water-laid strandline deposits at the base of the mineralisation are generally high grade, ranging from 20 to 60 per cent

Jan 1, 1973

By M Coulthard, J Rivalland, K Dugan

Prior to 2001 Yallourn Mine has pumped approximately 1000 Megalitres of water per annum from aquifers beneath the mine floor in order to control aquifer pressures that were thought to have an influence on mine floor and permanent batter stability. In 2001 one of the deep aquifer pumps was shut down for five months in order to measure the aquifer recoveries. Prior to the shutdown a UDEC model was created in order to predict what level of recovery in the aquifer pressures would be critical to mine stability. The shutdown showed that the aquifer levels recovered and stabilised at levels that did not threaten the stability of the mine. The aquifers recovered to levels below the critical levels identified in the UDEC model.

Jan 1, 2003