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OWING to two large falls of ground which resulted in serious accidents occurring towards the end of 1908, it became evident that the "open chamber" system then in use was unsuitable for the conditions existing in the Mount lVIorgan mine. It will be admitted that in all mining operation, the first consideration is the economy of the system adopted, combined with its safety and ability to give the desired output. A sectional system with square sets has been introduced into the mine, in which due attention has been paid to these factors. In this paper a brief description of this system will be given. An outline of those previously used will be ineluded, as it is necessary to understand the eonditions which existed in the mine at the initiation of the sectional system. Outside the actual mining methods employed, various points that might prove of interest will be touched on.The square set system of mining has been in use throughout the stopes in the gold ore in the upper levels of the mine since underground operations were started in Mount Morgan.

Jan 1, 1910

By R J. Holmes

An accurate knowledge of the chemical, mineralogical and physical characteristics of ores and mineral products that are mined, processed and traded is crucial to effective resource utilisation, plant design, process optimisation and finally quality control to ensure that contract specifications are met. However, all too often the responsibility for sampling is entrusted to managers and personnel who do not fully appreciate the significance and importance of collecting representative samples for analysis, and everyone seems satisfied as long as some material is collected and returned to the laboratory for analysis. Furthermore, sample stations incorporated into the design of new plants are often the first casualties when cost cutting exercises commence. This needs to change, because there is little point in accurately analysing samples if they are not representative in the first place. The resultant analyses can be next to meaningless and the effort taken to analyse such samples is to a large extent a waste of time and resources.Ultimately, a poor knowledge of the characteristics of ores and mineral products limits the ability of mining companies to optimise the life of ore resources and plant performance, and failure to meet final product specifications can have disastrous consequences, including price penalties and more seriously loss of sales contracts. It is high time that sampling is given the attention it deserves as the first critical step in the quality measurement chain.CITATION:Holmes, R J, 2013. The importance of sampling in the mineral industry, in Proceedings MetPlant 2013 , pp 34-49 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By G P. Taylor

Mining Lease SML 57 was registered to Mount Kasi on 5 January, 1995. The Mount Kasi gold mine is located in Vanua Levu, Fiji's second largest island and operated from 1932 to 1946 producing 261,000t of ore at an average grade of 7.5g/t Au. The deposit represents a structurally controlled style of high sulphidation copper gold mineralisation with peripheral low sulphidation mesothermal vein type gold mineralisation. The resource consists of 1,048,000 tonnes of residual soils (eluvium) containing 1.9 g/t Au at 0.5 g/t Au cut off and 1,240,000 tonnes of hard rock at 3.0 g/t Au and 1.0 g/t Au cut. 94 drill holes, 298 auger holes and 85 pits were modelled to outline the resource. 29% of the pits bottomed in mineralisation and it is likely the full thickness of eluvium has been understated. The pit is scheduled to produce 500,000 tonnes of ore per annum to yield 35,000 ounces of gold with an initial 2 years of eluvial ore followed by a further 2 years of hard rock ore. Total capital costs are estimated to be less than 10.0 million dollars with construction planned to commence in 1995. The likelihood of locating further ore is high.

Jan 1, 1995

The excavatability of the rock mass in a proposed open pit mine at Globe-Progress has been assessed. The rock mass was initially evaluated by determining variations in seismic velocity and by using the Revised Size-Strength Chart. These two assessments should be performed during the feasibility or early investigation stages of a project. A complete rock mass excavatability assessment using a suite of geological and geotechnical properties was then performed using three methods: RMR System; Modified Rippability Rating; and a productivity estimation method. These three methods should be applied during the investigation and design stages of a project. The preliminary assessments show that most of the open pit rock mass is expected to be rippable. The complete assessment differentiates weak, fair and good rock masses within the open pit. Weak rock mass exists along the Globe-Progress Shear zone, located along the northern and eastern pit walls and also in the western pit wall where the Chemist Shop Fault is located are both regions are expected to be diggable. Relatively weak rock mass also exists along the Globe-Progress Shear axial hinge. The Globe-Progress Shear limbs are generally fair to good rock where moderate to hard ripping should be expected.

Jan 1, 1996

Removal of As(III) and As(V) in Aqueous Solution There are toxic arsenical species such as As(III) and As(V), and arsenious species have specially strong toxicity. The strong toxicity causes contamination of groundwater and water pollution for the semiconductor production process. This study is concerned with the removal of As(III) and As(V) with various kinds of Mg/Al layered double hydroxides (LDH) containing CO32-, SO42-, Cl- and NO3- as interlayer anionic species. The anion exchange property is different from the kind of layered double hydroxides and the Mg-Al-NO3-LDH is superior in the anion exchange property of As(III) and As(V) due to the nature of nitrate ion existing in the interlayer. The pH condition suitable for As(V) removal is 7.1 or more. If the initial conditions such as 10mg/dm3 of As(V) concentration, 7.1 of pH, 1 m3 of amount of solution and 99 per cent of removal are fixed, the required amount of Mg-Al-NO3-LDH is 0.27kg for two step-batch operations. The As(III) is suitable to oxidize to As(V) before the removal processing.

Sep 13, 2010

By J Bresnahan, D Kepert, R Murray, R Neroni

Stratigraphy of the Hamersley Province in Western Australia, featuring alternating units of banded iron formations and shales with contrasting electrical properties in a mostly gently undulating shallow-dipping layered geometry, is particularly favourable to airborne time-domain electromagnetic mapping techniques. Manipulated vertical cross-sections of modelled conductivity obtained from laterally constrained one-dimensional inversion of SkyTEM304 data enable the exploration geologist to interpret weathering profiles, shallow-dipping stratigraphy and steep structures, all of which are crucial aspects of bedded iron ore deposits genesis models.The Cobra Project is located 14 km east of the NNW-trending Menindee Fault Zone, which defines the western margin of the Hamersley Province, Western Australia. The region comprises an extensive plateau of Brockman Iron Formation cut by a series of horst and grabens with a regional dextral strike-slip component. The 150° striking horst and grabens and associated 060° striking conjugate faults have approximate frequencies of 400 and 2000 m, respectively, and control the bulk of the iron mineralisation. Syn to late 150° trending dykes in part intrude the faults.In the Cobra region, elucidating the structurally dislocated stratigraphy without closely spaced drilling is very challenging. Geological mapping is hindered by the paucity of mappable stratigraphic markers within the banded iron formations and kinematic indicators. Airborne magnetic and remote sensing data sets highlight the dense lineament network, but provide limited assistance in quantifying relatively small apparent displacements, or distinguishing faults from dykes with reasonable confidence.Interpretation of modelled conductivity cross-sections generated from laterally constrained one-dimensional inversion of airborne electromagnetic method (AEM) data offers invaluable insight where the quality of mapping or drilling is wanting. Subsequent targeted field checking and infill drilling validated the geological model interpreted from the integration of these data sets.The AEM technique alone cannot decipher the complex geological environments often present in the Hamersley Province but can facilitate effective iron ore exploration by focusing precious field time and assisting structural and stratigraphic interpretations in areas with sporadic and shallow geological data.CITATION:Murray, R, Neroni, R, Kepert, D and Bresnahan, J, 2017. Using airborne electromagnetics to solve a structurally complex geological puzzle in the Hamersley Province, Western Australia, in Proceedings Iron Ore 2017, pp 269–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By D N. B Skinner, R L. Brathwaite, M S. Rattenbury

The Institute of Geological and Nuclear Sciences Ltd has carried out a mineral resource assessment of the Coromandel region, one of the most mineral-rich regions of New Zealand. The assessment focussed on metallic minerals and clays, because these are the main commodities that have potential for increased production and export from the region (and from New Zealand).   Three steps were used in the assessment: 1) development of mineral deposit models, 2) comparison of the models with regional geology, structure, geochemistry and past mineral production to estimate the number of undiscovered mineral deposits, and 3) application of grade-tonnage models to determine the quantity and value of the known and undiscovered resources. In step 1, descriptive and grade-tonnage mineral deposit models were developed for 11 different types of mineral deposits: ò     Low-sulphidation andesite-hosted epithermal Au-Ag ò     Low-sulphidation rhyolite-hosted epithermal Au-Ag ò     High-sulphidation quartz-alunite epithermal Au ò     Porphyry Cu-Au-Mo ò     Andesite-hosted polymetallic veins adjacent to mineralised porphyry stocks ò     Zn-Pb-Ag skarn ò     Cu-Ag skarn ò     Hot spring Hg ò     Shoreline placer Ti ò     Rhyolite-hosted halloysite clay ò     Volcanic-related kaolinite clay   Step 2 was aided by a geographic information system (GIS) assembled from a number of digital spatial data sets including: a digital elevation model, an aeromagnetic map (from open file mining company data), a geological map (from the GNS QMAP project), location of areas of hydrothermal alteration, locations of mineral deposits (from the GERM database), stream sediment geochemical analyses (from the REGCHEM database), and a lineament map derived from satellite remote sensing data and the digital elevation model.   Based on May 2001 commodity prices, potential resources estimated for the 11 mineral deposit and grade-tonnage models total NZ$22 806 million for the metallic minerals, NZ$1000 million for halloysite clay deposits and NZ$57 million for kaolinite clay deposits.

Jan 1, 2001

The Effect of Ionic Strength of Plant Water on Valuable Mineral and Gangue Recovery in a Platinum Bearing Ore from the Merensky Reef

Sep 13, 2010

Seam correlation in the central Rapahoe Sector (Greymouth Coalfield) can be enhanced by detailed lithostratigraphy and chronostratigraphy. Rewanui Coal Measures are overlain comformably by lacustrine, deltaic and fluvial strata, and this upper contact can be located using lithological and geophysical log character. The Cretaceous-Tertiary Boundary (KTB) occurs near the top of Rewanui Coal Measures and has been identified palynologically in 16 drillholes. The Rapahoe Sector can be subdivided into two palynostratigraphic domains which adjoin along a basement normal fault which was downthrown to the north during coal measure deposition. The KTB provides an isochronous surface which is independent of the lithostratigraphic datum. Using the KTB as a datum, the æUpperÆ, æMainÆ and æSubmainÆ seams can be reliably correlated throughout the southern and central Rapahoe Sector. Similarly, the æSubmainÆ seam can be correlated with æcÆ seam of the Strongman Mine area, though other Strongman seams are absent from the central and southern Rapahoe Sector.

Jan 1, 1996

By G C. Bolton

Experiments were conducted to access the feasibility of removing zinc from lead slag by sulfation or chlorination or both. Gaseous sulfation with sulfur dioxide and oxygen released only 50 per cent of zinc even under the most severe conditions. Sulfation with concentrated sulfuric acid by a fast-leach process released 95 per cent of zinc while pug-roasting released a maximum of 78 per cent of zinc. Chloridization with NaCl in the presence of sulfating gas released 50 per cent of zinc, while direct chlorination with chlorine gas and oxygen released 85 per cent of zinc and 100 per cent of lead in a chloride condensate containing little impurities.

Jan 1, 1980

This paper highlights the agricultural sector's primary concerns with mining in New Zealand: the information gap, land rehabilitation and compensation. It suggests how these issues can be resolved between the competing land uses in the interests of New Zealand.

Jan 1, 1981

Delhi Australian Petroleum Ltd., acting as operator for the joint interests of Delhi and Santos Ltd., has been engaged in petroleum exploration in the western Great Artesian Basin since 1958.Extensive airborne magnetometer, gravity meter, reflection and refraction seisomograph, and surface geological surveys have been carried out. Results of the surveys have considerably altered the concepts of the geology of the area.Seven exploratory wells have been drilled in the area. Results of the drilling have established the presence in the subsurface of previously unknown Paleozoic sediments which are capable of generating hydrocarbons.Production of oil or gas has not been achieved, but each phase of the exploration programme has resulted in progressively establishing the basic conditions necessary for the discovery of commercially profitable accumulations.INTRODUCTIONDelhi Australian Petroleum Ltd. commenced operations in Australia in 1958. They have subsequently been engaged in systematic exploration for oil and gas, acting as operator for their partner, Santos Limited. The methods and techniques employed are those used throughout the petroleum industry. The results of the exploration programme contribute to a better understanding of the basic geology, and concomitantly a firmer analysis of the petroleum producing potential, of the western Great Artesian Basin.Each phase has progressively enhanced the gross geological interpretation of the area with regard to favourable conditions for the generation and accumulation of hydrocarbons, but the stage has not been reached where productive potential is definitely established.Exploration status in 1958Basin configurationIn 1958 knowledge of the pre-Jurassic stratigraphy of the geographically defined western Great Artesian Basin...

Jan 1, 1964

By M Berry, F MacCorquodale

The ownership, management and employment structures operating in the Australian minerals industry have dynamically evolved during the last 30 years. One of the most dramatic changes, from an exploration and mining geology perspective, is the reduction of in-house geological expertise and an ever increasing reliance on contract and consulting services.For all companies - big and small - two key issues resulting from these changes are the management of core geological intellectual property (IP) and competitive advantage. This is because there are less experienced geologists at exploration and mine sites, there are fewer head-office technical service teams to support mine sites, exploration teams are smaller with less specialists employed, and there is an ever-greater dependence on contract and consulting services.This paper reviews and explores these issues with an industry-wide geological context, then provides a case study of how Newcrest Mining Limited (Newcrest) has dealt with these issues in exploration. Newcrest has grown from a one-mine company with an Australian exploration focus, to a large global company with multiple operations and an extensive international exploration portfolio. NewcrestÆs management of its geological IP and competitive advantage has evolved as the company has grown and responded to market conditions, including its internal restructuring in mid-2013.CITATION:Berry, M and MacCorquodale, F, 2013. Managing geological intellectual property and competitive advantage - Newcrest Mining LimitedÆs experience, in Proceedings World Gold 2013 , pp 37-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By R J. Goldfarb

Reduced intrusion-related gold deposits have become a new, low-grade, large-tonnage exploration target during the last decade. The best recognized examples of such deposits are recognized throughout the Tintina Gold Province of the northern North American Cordillera. Because such examples may have many features in common with orogenic gold deposits, such as anomalous Bi, W and Te, low salinity and CO2-rich ore fluids, and a spatial/temporal association with igneous rocks, confusion and controversy have now become commonplace in classification of many gold deposits formed along convergent margins. The best discriminators of IRGS are likely to be their: +        regional location in deformed shelf sequences on the inboard side of a series of accreted terranes and within terranes that also contain important tin and (or) tungsten deposits; +        local spatial association of gold ores with cupolas and contact aureoles of relatively reduced, alkaline-leaning, and volatile-rich plutons; +        post-deformational timing of gold deposition; +        extremely low sulfide content (commonly <1 vol %) of ores within igneous bodies and the outward zoning, through proximal skarns and to distal base metal-rich veins, from the causative pluton; and +        low grades (<1 g/t Au) of auriferous sheeted vein systems in pluton cupolas.

Jan 1, 2005

By X Yang, B Wang, L Liu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Huoqiu iron ore field in north-west Anhui province is located in the south-east margin of the North China Craton and hosts large iron resources. Orebodies are hosted in Neoarchean amphibolite facies metamorphic rocks, forming silicon-iron bands from north to south. The area is dominated by an Early Precambrian basement consisting of Neoarchean grey gneisses, amphibolites and metasediments. The gneisses are similar with assemblages of Trondhjemite-Tonalite-Granodiorite in compositions and intercalated with amphibolites. Igneous zircons from gneisses and amphibolites have U-Pb ages of 2.86 and 2.75 Ga respectively, which are interpreted as the crystallisation ages of their protolith. Zircons from amphibolite and gneiss have eHf(t) values of 2.4–15.5 and -3.0–1.5 respectively. The tDM2(Hf) model ages of the gneiss range from 2.87 to 3.14 Ga, which is consistent with tDM1(Hf) ages of amphibolite (2.84–3.16 Ga). The U-Pb-Hf isotopes thus confirm that the gneisses were generated by partial melting of amphibolite. Two granites produce two group Hf isotopic compositions. The older one (1916 ± 42 Ma) has eHf(t) values and tDM1(Hf) ages of -9.4–3.4 and 2.24–2.71 Ga respectively, whereas the younger one (1823 ± 41 Ma) shows a large variation in eHf(t) values of -18.1–12.5 and tDM1(Hf) model ages of 1.73–2.92 Ga. Geological and geochemical characteristics indicate that the Huoqiu banded iron formations are a Superior-type iron formation rather than an Algoma-type as previously considered.CITATION:Yang, X, Liu, L and Wang, B, 2015. Study on the Huoqiu banded iron formation, West Anhui Province, East China , in Proceedings PACRIM 2015 Congress, pp 649–656 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The pyrite-sphalerite-galena and barite orebodies at the Rosebery mine are concordant with the shale host rock and have been deformed into one system of folds with an associated axial plane cleavage. The folds are tight and overturned with east-dipping axial planes. Folds in the sulphide ore are commonly disharmonic, particularly between adjacent bands of different composition.Concentric style folds occur in the competent bands, e.g. pyrite-rich bands. Similar style folds are predominant in the less competent sphalerite-galena-rich bands and also in the shale of the host rock. The trends and plunges of the fold hinge-lines are variable but axial planes are of reasonably constant orientation throughout the mine area. The folds in the orebodies are of limited axial extent, approximating to conical folds, and are arranged in en echelon patterns. The fold system was possibly formed in one period of folding by heterogeneous strain that may have been caused by the presence of a mass of tectonically mobile sulphide ore. Lineations parallel to the ore/host rock contacts appear to reflect movement between the ore and the host rock during folding.

Jan 1, 1972

By I Halikia, T Lilis

Lead smelter slags, produced during the last century in quantities ofmillions of tonnes at Lavrion, Greece, have recently been used in theconstruction of Lavrion harbour. In order to evaluate the geochemicalstability of slags and assess their environmental impact on the aquatic environment, a detailed study on lead leachability under conditions that simulate subsea environments was carried out. Leaching experiments using magnesium chloride solutions under mild temperature conditions were conducted and the effect of main parameters on lead solubility was examined. Furthermore, kinetic analysis on the experimental results was performed. Based on the results, lead dissolution increases by increasing the reaction time, magnesium chloride concentration in the bulk solution and temperature, whereas it decreases by increasing the slags particle size. The reaction order was found to be approximately 0.5 at the initial extraction stages and the activation energy value from the Arrhenius plot was estimated to 29.8 KJ/mole. Diagnostic equations applied to all the experimental data reveal that lead dissolution is mainly controlled by diffusion through the ferrosilicate matrix of the slag particles, which is in accordance with the low activation energy value. The JanderÆs diffusion equation [1-(1-a)1/3]2=kt was proposed as the equation representing the reaction of lead dissolution from slags using magnesium chloride solutions.

Jan 1, 1999

By D Brooks, S Gunn, T Perkins, J Siliezar

Ernest Henry Mining (EHM) is a copper, gold and magnetite mining and processing operation located 38km north east of Cloncurry. The EHM ore body has an average grade of 0.9% copper (chalcopyrite), 0.5g/t gold and 22% magnetite.Open pit mining commenced in March 1998, but EHM transitioned to underground mining in December 2012, extending the life of operations beyond 2024. The underground mine currently produces up to 3Mt/year of ore, hauled up a decline by truck. This figure shall double in 2014 with the completion of a 1000m shaft. The EHM Concentrator has a nameplate capacity of 10Mt/year. In June 2011, Xstrata Copper acquired the Mount Margaret resource to supplement underground production and utilise the full capacity of the Concentrator. The Mount Margaret Mining (MMM) operation was established to develop the five deposits making up the resource by way of open pit mining.Copper concentrate is produced by the EHM Concentrator via grinding, flotation and dewatering circuits. The grinding circuit comprises a SAG and ball mill in a closed AB configuration. Flotation consists of a rougher train, regrind and three stages of cleaning, with the tail from the first stage reporting to the tailings thickener.The mineralogy of the MMM ores is complex, comprising fine textures of active pyrite, copper oxides, native copper, clay and secondary copper sulphides. This paper provides an overview of the metallurgical test work completed to forecast the performance of the MMM ores through the EHM Concentrator and identify flow sheet modifications for maximising copper recovery and producing a saleable concentrate. A discussion of the challenges experienced in the plant to date follows.CITATION:Gunn, S, Siliezar, J, Brooks, D and Perkins, T, 2013. Adapting the Ernest Henry Mining concentrator to process the Mount Margaret ores, in Proceedings MetPlant 2013 , pp 347-370 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By H Thanasekaran, J Kohmuench, B Seaman

To achieve an efficient separation in the flotation process, valuable particles need to be selectively segregated from the gangue while utilising a minimum number of flotation stages. TodayÆs existing flotation technologies are effective for fine particle size classes; however, limitations due to particle buoyancy and bubble-particle detachment restrict the effectiveness of traditional flotation approaches on coarser particles. As a result, flotation circuits are generally configured to process only fine particle size classes in order to maximise recovery in the primary stages. Eriez has invented a novel flotation technology, the HydroFloat, which overcomes these limitations by carrying-out flotation in a dense, fluidised-bed medium allowing for the recovery of coarse particles (>0.250 mm). Over the last 15 years, this technology has been successfully applied to industrial minerals with several full-scale units installed to recover particles up to and exceeding 3 mm diameter in primary flotation circuits. This paper includes discussions on the history of this technology, process theory, existing applications, and a review of recent sulphide-based laboratory test work conducted for Newcrest mining and others. Benefits of this approach, such as improved recovery, low energy consumption and reduced reagent addition will also be reviewed.CITATION:Kohmuench, J, Thanasekaran, H and Seaman, B, 2013. Advances in coarse particle flotation - Copper and gold, in Proceedings MetPlant 2013 , pp 378-386 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Predicting the future is a task that should always be delegated. If that is not possible, then stating your views confidently, but retrospectively, is preferable. Hindsight encourages clarity of thought and sharpens perception. When all else fails one can look back into history and see the trends, evaluate the current situation and project it a little way into the future - in this case 10 years. In exploration the rate of change has been increasing over the past 20 years. With expected developments in technology, legislation, and their sociological impacts, we will see such rapid change over the next decade as to make us uncomfortable, unless we are prepared for it.   The social obligations of our industry also have changed enormously over the past 20 years and are still changing. This will lead to further changes in the way we conduct our business if we wish to stay in business. As exploration technology improves, a further dimension is added by the expectations of the communities in which we operate. This extra dimension needs to be quantified so that we not only keep up with current developments but also get ahead of the game. This paper is based on the New Zealand experience, some of which will be familiar to mineral explorers in other countries.

Jan 1, 1997