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By D R. Peacor, J L. Mauk

Dioctahedral clay minerals in the volcanic-hosted Golden Cross epithermal Au deposit, New Zealand, have been investigated by petrography, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy/analytical electron microscopy (TEM/AEM) to determine the nature of these minerals in a hydrothermal ore deposit. Heterogeneity in the distribution of dioctahedral clays is observed from the hand-specimen scale to the TEM scale, indicating that primary rock textures and fluid pathways (related to rock type, porosity/permeability and fluid/rock ratios), in addition to temperature, are important factors controlling the distribution. As the proportion of illite in mixed-layer illite/smectite (I/S) decreases, TEM observations show decreasing layer stacking order, parallelism of packets, and packet size, and increasing apparent porosity. AEM structural data show a corresponding decrease in AlIV, AlVI, and K+, and an increase in Si, Ca2+, and Fetotal. The observations of this study indicate that local dioctahedral clay mineral reaction progress is controlled mainly by permeability and structure, but that this is superimposed on a predictable, system-wide clay mineral distribution that is controlled by temperature and fluid/rock ratio.

Jan 1, 1999

By A Turichshev

The synthetic rock mass (SRM) approach for modelling jointed and veined rock has been at the forefront of caving geomechanics research for years. A well-constructed and calibrated SRM model can capture the full rock behaviour at a macroscopic scale. Traditionally, SRM technology employed bonded particle models (BPM) due to their ability to model rock’s response to loading without prior specification of behaviour. The SRM modelling process requires the BPM to simulate intact rock and the subsequent introduction of fractures or veins by changing bonding characteristics between the particles. However, bonded particle materials have difficulty reproducing both the compressive and tensile strengths of intact rock. This and other limitations of BPM have been the driving force in exploring the potential of grain-based (2D) and bonded block (3D) models (BBM).This paper reports on recent work exploring the applicability of both BPMs and BBMs in 3D to the modelling of intact rock. The advantages and limitations of both BPMs and BBMs are addressed based on the results of numerical simulations using the PFC3D and 3DEC distinct element codes. The preliminary results suggest that BBMs are better suited for simulating intact rock behaviour than BPMs. Ongoing work aims to better qualify the applicability of BBMs under different conditions. This has significant implications for our understanding of rock mass behaviour in a caving environment.CITATION:Turichshev, A and Hadjigeorgiou, J, 2016. Simulating intact rock behaviour using bonded particle and bonded block models, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 453–460 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Young D. R, Webb I. D

The hydro-chlorination of Fe2O3 and Fe304 has been investigated in the range 850-950¦C in order to elucidate the role of iron in the segregation process for nickeliferous laterites. The kinetics of Fe203 chlorination using 20% HC1 - 80% N2 gas mixtures is consistent with a single-stage structure control model, whereas Fe3O 4 exhibits a two-stage reaction mechanism. Oxygen potential measurements using a CSZ probe located above the bed and X-ray powder diffraction results confirm the proposed reaction scheme. When a serpentine nickeliferous laterite (1.03% Ni - 11.7% Fe) was chlorinated at 900¦C with a 20% HCl - 80% N2 gas mixture it was found that the iron oxide in the ore was extracted in a similar manner to the synthetic iron oxides. Also, it was found that the nickel extraction from the ore paralleled that of the iron and the tests indicated that for the major part of the extraction, the solid nickel species were in equilibrium with the gas phase. The recovery of nickel from laterite ores by the segregation process has been investigated by a number of workers and several extensive reviews of the literature associated with this field have been published (Iwasaki, 1972; Canterford, 1975; Wright, 1973).

Jan 1, 1987

By Teague JK, Read HW

The relationship between the maceral composition of coal and the strength of the coke produced from that coal has received a great deal of attention in recent years. Studies using two Bulli Seam coals, and blends of Bulli and Wongawilli Seam coals, from the Illawarra Measures of the Southern Coalfield of New South Wales were carried out. The optimum range of vitrinite was found to lie between 45% and 60% (mineral matter free). Above and below this vitrinite range coke strength deteriorated. I Coke strength indices increased with rank and the optimum vitrinite content increased with an increase in rank. These changes will require confirmation as trends by testing a third level of rank. It was noted that vitrinite content decreased with an increase in the specific gravity of separation of the coal. . T Use of- petrographic analyses will increase confidence in choosing coals for coking, provided the coals are well known. Such analyses offer the possibility of greater flexibility in coal purchases and the possibility of producing a marketable blend from coals, which have limited market potential. Critical base coals for blends can be conserved. Significantly more work is required before coal reserves can be utilised to optimum advantage. This work would require extension of-the studies discussed in this paper and, in particular, the testing of a wider range of rank.

Jan 1, 1970

By A Lu, C Wang

The natural semiconducting mineral rutile and sphalerite exhibited highly photocatalytic activities on degradation of methyl orange under visible light irradiation. The isomorphous substitutions of host metal ions by foreign ions and other defect states in natural semiconductors altered the band structure, decreased the intrinsic band gap, and then made them very attractive for solar energy utilisation. Our study indicated that natural semiconductor minerals might be suggested as a new class of cost-effective and solar light-responsive photocatalyst.

Jan 1, 2008

By L Bergin, D J. Williams, S Islam, T A. Vangsness

The flooding of open strip coal mines in the Bowen Basin and Hunter Valley Coalfields of Eastern Australia has the potential to soften the spoil and floor materials to produce “mud”. This mud can act as a slip plane or weak zone when spoil is dumped into it, resulting in geotechnical instabilities. Once mud has formed, typical handling techniques include its costly removal by mechanical means, or its isolation and capping.There are little data available on the moisture state and shear strength of the capped mud. To investigate the effectiveness of isolation and capping, research has been conducted using a large slurry consolidometer (150 mm in diameter by up to 410 mm in height) to simulate capping in situ. Once consolidated, the mud was subjected to shear strength testing in a direct shear box measuring 60 mm by 60 mm by about 20 mm high. The shear strength of the consolidated mud was compared to that of competent, fresh spoil, a mixture of spoil and mud, and to completely degraded spoil (mud alone).These results have been used as inputs in stability calculations using the commercial computer program Slide 7.0, which demonstrates the strong influence of consolidation of the mud on overall low wall slope stability. The results provide insight into the design and construction of capping to isolate in-pit mud.CITATION:Vangsness, T A, Williams, D J, Islam, S, Smith, A and Bergin, L, 2018. Consolidation and shear strength testing and stability analysis of coal mine spoil degraded to mud, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 97–109 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Lauha E. A

The Goldstrike Mine is in Eureka County, Nevada, U.S.A., approximately 23 miles northwest of the town of Carlin. The mine is at the north end of the Tuscarora Spur of the Tuscarora Mountains at elevations of 5,300 feet to 5,950 feet. It is part of the Bluestar/Goldstrike subdistrict of the Carlin Trend, a northwest alignment of sediment hosted, disseminated gold deposits. The Carlin Trend includes over 15 major gold deposits with production, reserves and geological resources of approximately 65 million ounces of gold (Figure 1). In the Bluestar/Goldstrike subdistrict, there are seven major deposits; Betze, Lower Post, Post, Genesis, Bluestar, Purple Vein and Deep Star, plus numerous smaller deposits (Figure 2). Production, reserves and resources for the subdistrict are approximately 40 million ounces. Betze and Purple Vein are located on property controlled by Bamck Goldstrike Mines and Bluestar and Genesis on Newmont Gold property. Post, Lower Post, and Deep Star occur both on Barrick and Newmont Property.

Jan 1, 1991

Interest in the sampling of refined copper cathodes has heightened over the last ten years. This has followed the increasing importance of cathodes as the principle trading form for metallic copper. It has also been given impetus by recent trends for quality certification of manufacturing inputs, specifically the AS3900 and IS09000 series of standards.

Jan 1, 1976

By Paine G. G

The measurement of the fragmentation size distribution of a blast muckpile can be achieved directly by screening the entire muckpile. Screening of muckpiles in a production operation is generally not practical due to the logistics and time involved moving large volumes of rock through a screening plant. An indirect technique to assess blast fragmentation size distributions has been developed. This technique uses photographs of the blast muckpile taken at intervals during the excavation cycle. The images from the photographs are input to desktop computer software via a digitiser tablet. The software compilates the rock fragment sizes and calculates a size distribution. This paper discusses the technique and subsequent data analysis. Examples of the application of this technique for the assessment of comparative blast performance are given.

Jan 1, 1990

By Nakajima A

Some attempts were made to recover uranium from aqueous systems by using various biosubstances including microbial biomass. Of hundreds species of microorganisms tested, extremely high uranium absorbing ability was found in Pseudomonas stutzeri, Neurospora sitophila, Streptomyces albus and Streptomyces viridochromogenes. In parallel to this research, various kinds of biomass and commercially available crude drugs were screened to measure their abilities to adsorb uranium. Of these biosubstances tested, high uranium adsorbing ability was observed in chestnut skin, Comi fructus, Geranii herba and Chaenomelis fructus. From these results it may be considered that the uranium adsorbing ability of these biosubstances is due to the following; the uranyl ion is co-ordinated by the polyphenolic compounds such as tannin existing in the biosubstances. Along with these fundamental researches, we have developed a new adsorbent, the immobilised persimmon tannin (kakishibu tannin), for uranium and thorium. This adsorbent can accumulate 1.71 g of uranium per gram of the adsorbent (14 mEq/g), and the uranium adsorbing capacity of this adsorbent exceeds by several times that of commercially available chelating resins (2 - 3 mEq/g). We attempted to recover uranium from uranium refining waste water by using the immobilised persimmon tannin. As a result, the immobilised persimmon tannin can recover trace amounts of uranium from uranium refining waste water containing 10 - 15 ppb uranium with high efficiency. Almost all of the uranium adsorbed onto the adsorbent can be desorbed by washing with 0.05 - 0.1 M HCl or H2SO4. Thus, the immobilised persimmon tannin can be used repeatedly in the adsorption-desorption Cycle.

Jan 1, 1993

By D A-F Batchelor

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.South-East Asia represents the world’s most productive tin province, mainly from placers. Kalimantan has been a major diamond producer, while in the 1980s a placer gold rush occurred in Indonesia and Malaysia. Reviewing extensive geological and mining data highlights phenomenal palaeo-environmental changes in the Sundaland region, interpreted to be responsible for generating ‘giant’ placers. Correlation of the Late Cainozoic stratigraphy has been facilitated from mine exposures and drill holes distributed throughout Peninsular Malaysia, the Indonesian Tin islands and Kalimantan, including contiguous marine areas with extensive shallow seismic profiling data. Knowing the association of rich placers with palaeo-environmental episodes and stratigraphical units has been helpful to facilitate their discovery. All three placer commodities responded similarly to region-wide landscape evolution following Mio-Pliocene high sea levels. Commencing with major regression, important stages comprised: a long period of landscape stability with deep weathering during the maximum Sundaland extent gradually rising sea levels/precipitation initiated slumping of mineralised regolith to form fans, later reworked by braided streams with aggradation (Old Alluvium); during episodic pluvial periods downcutting upgraded placers significant change occurred around Middle Pleistocene time with peneplanation and pedogenesis from Late Pleistocene time ‘modern’ fluviatile deposition (Young Alluvium) filled incised V-shaped valleys.Placer seams show systematic variation in stratigraphic position, in particular cassiterite especially occurs in the Old Alluvium (equivalent Upper Dahor Formation in Kalimantan). Gold is commonly richer in gravelly younger deposits, partly because of secondary precipitation within permeable alluvium. Reworked diamonds are predominantly concentrated especially in younger fluviatile alluvium.CITATION:Batchelor, D A-F, 2015. Conceptual exploration for tin, gold and diamond placer deposits in ‘Sundaland’ (Indonesia and Malaysia) by understanding the late Cainozoic stratigraphic context, in Proceedings PACRIM 2015 Congress, pp 499–506 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Mez W

the German ruining industry uses different residues for hackfilling and stowing. A hydraulic pipe conveying technology for these materials has shown advantages for the transportation into the mine. Pipeline conveying systems are able to bridge long distances, they save room within the underground workings and they save staff and costs. Absolutely necessary for successful use of the hydraulic conveying technology is the knowledge about the unusual non-Newtonian flow properties of solid/liquid mixtures like pastes and slurries. The flow resistance of these materials cannot be described easily by one viscosity. Owing to a yield point and a pseudo-plastic behaviour the viscosity changes with the shear rate and with the streaming velocity inside the pipe. Also these flow behaviours depend very sensitively on the liquid/solid-ratio, often so dramatically that gravimetric or volumetric dosing equipment is not in a position to control the production of backfill pastes. Quality changes of the solid raw materials (particle size distribution, density, mineralogical composition) lead to additional difficulties. The first experiences with hydraulic backfilling plants were troubled by plugged pipes. a bad backfill quality caused by unnecessarily high water content and high costs for chemical binders to solidify the backfill. The installation of viscosity controlled paste production leads to success with the hydraulic backfill technology. A development of the l)MT, a bypass pipe-viscometer, has been the key technology. The system is able to analyse on-line, difficult, sticky and abrasive substances and determine their non-Newtonian flow properties. Because the system measures real physical values it is in a position to pre-calculate process relevant parameters like the pressure drop of the backfilling paste in the conveying pipeline. Newer types of the viscometer system also measure the slurry density and calculate its composition. These systems have proven a success controlling backfill paste production plants. They offer it secure prevention of pipeline plugging and a production of high quality backfill pastes with a water content as low as possible.

Jan 1, 1998

The geologic settings, geochemistry of host rocks, mineralogy and metal values in modern back-arc volcanic-hosted massive sulphide (VHMS) mineralisation are very similar to those in many ancient polymetallic VHMS deposits. The geology, distribution and styles of seafloor mineralisation in modem back-arc basins, especially the eastern Manus and Lau Basins, southwest Pacific, are compared to VHMS deposits in the Mount Read and Mount Windsor districts of Australia . Based on exploration and research in modem back-arc settings, geologists are now observing the direct analogues of the polymetallic VHMS deposits currently being exploited in ancient back-arc volcanic belts throughout Australia and the world.

Jan 1, 1995

By Wright S, Jorgensen F. R A

The reaction between lead sulphate and a number of base metal sulphides (galena, sphal- erite, chalcopyrite and synthetic pyrrhotite was studied as a means of desulphurizing lead sulphate containing fumes and residues to levels acceptable as ISF feed. The reactants were mixed with 50% zinc oxide to act as a "basket" to contain the molten products of the reaction and pressed into small briquettes 20 mm in diam. Factors such as temperature, time and the composition of the atmosphere were investigated. Using the PbS/PbS04 system as an example it was shown that the reaction became rapid above 800¦C and that both sulphur dioxide and oxygen in the atmosphere were detrimental to achieving low sulphur in the product. In an inert atmosphere all the sulphides when roasted for 1 h at 1000¦C gave results corresponding to the elimination of more than 95% of the sulphur in the reactants. Leach plant residues were considered for use as the "basket" material. It was shown that the residual sulphide and sulphate components of the residues underwent similar reactions to those experienced by the pure systems.

Jan 1, 1987

By P Holt, M Allen

On the first of July, 2012, the Australian GovernmentÆs Clean Energy Act commenced. From this point, a price of $23/t of CO2-e will apply to facilities that trip the liability threshold. This first part of this paper concentrates on the mechanics of the Clean Energy Future legislation and how it will be applied to the mining and mineral processing industry.The second part of this paper contains analysis of the data presented for typical mine operations. Methodologies for constructing a carbon strategy are also presented. This will entail determining what the objectives of the carbon strategy are, and defining what the strategic priorities for a business should be. An action plan to address the risks identified from the Clean Energy Act is also developed as part of the strategy.Details such as the advantages and disadvantages of opting into the carbon price scheme for liquid fuels are shown. Other considerations such as the ability to acquire permits through the carbon farming initiative or through overseas clean development mechanism projects are explained.CITATION:Allen, M and Holt, P, 2012. Implications of the carbon price and developing a carbon strategy, in Proceedings International Mine Management 2012, pp 105-114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By P González, J Videla, E Córdova, I Gottreux

Currently, underground mining of deeper massive deposits with lower grades, harder rock conditions in high strength environments, entails difficulties in caving, fragmentation and seismicity of the orebody.So far, the use of preconditioning (PC) with hydraulic fracturing (HF) has shown positive results in terms of seismic response and caving performance, while PC combined with explosives aims to weaken the rock mass, causing an additional effect on fragmentation.In particular, mines commonly referred to as ‘supercaves’, operated by caving methods, have the need to integrate mine to plant processes, where rock fragmentation appears as a key tool. In fact, it implies making mining and comminution processes more efficient to the plant and for mines, it justifies the search of innovative solutions in drilling and blasting techniques to precondition the rock mass. The following paper aims to show the feasibility of numerical blast modelling to weaken the rock mass using explosives, mainly through sensitivity analysis applied to designs to minimise bias and uncertainty in the results. It is shown how the presence of structures, their geometry and in situ stresses influence or interfere with the PC method being used.From the work, it is concluded that better knowledge on the application of explosives weakening allows specialists to strengthen numerical models associated with every design and therefore previously validate their applicability, helping to understand complex phenomena such as the propagation of mechanical waves in non-elastic heterogeneous media. In this sense, it is understood that while there are studies (Sanchidrián, Segarra and López, 2006) showing that the transfer of energy in the rock mass could be even greater in a confined environment, the more competent rock mass and higher in situ stresses interfere mostly on the effectiveness of a technique using explosives.CITATION:Gottreux, I, Córdova, E, González, P and Videla, J, 2016. Preconditioning modelling and explosives effectiveness in block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 683–688 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By S M. Jowitt, G M. Mudd

"The mining industry is the source for the vast majority of the metal, mineral and energy resources we use on a daily basis. New deposits are discovered over time and are developed into mines before being rehabilitated – a sequence that when repeated can help contribute to the noble notion of ‘sustainable development’, despite the generic concept of mining being the unsustainable consumption of non-renewable resources. The scale of the modern mining industry is immense – from iron ore and coal to base and precious metals, modern mines are sometimes hundreds or thousands of times bigger than their long lost historic ancestors. We also live in a world with emerging and increasing demands for so-called technology metals (aka ‘critical’, ‘e-tech’ or ‘specialty’ metals) that are needed to feed the rapid growth in renewable energy (especially solar photovoltaic panels and wind turbines), consumer electronics, sophisticated military technologies and super alloys, amongst other uses. These elements include the rare earth elements, indium, germanium, tellurium, rhenium, selenium, gallium and many others, most of which had few or no known uses in the recent past. Although the mining industry has been successful in developing ever larger mines and increasing the scale of production, the key issues underlying the future of the industry are declining ore grades, increased tailings and waste rock generation, the presence of toxic or other impurities, balancing the economics of primary and secondary products, stricter environmental conditions, more difficult exploration, increasing community expectations, as well as the processing of more complex or refractory ores, let alone the recent volatility in world commodity markets. Here, we synthesise our recent research on many of these various issues, focusing on the need to link all areas within the mining chain from mineral resources through mining to environmental performance in order to ensure we obtain the most out of our modern mining effort. The paper presents a unique and detailed assessment of the sustainability challenges and opportunities facing modern mining – and geometallurgical thinking is at the heart of this conundrum.CITATION:Mudd, G M, Jowitt, S M, 2016. From Mineral Resources to Sustainable Mining – the Key Trends to Unlock the Holy Grail?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 37–54 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

By O C. Aitken

Mining project developers are committed to taking on all the challenges and obligations of financial risk management. It is interesting that our current models of project finance have not changed markedly in principle for some 700 years, yet the rules which prepare the way for effective project assessment and subsequent loan management still do not seem to be well understood by project or corporate developers. Probability and gravity fill the opposing trays of the golden balance of financial risk. Understanding the relationship between these opposing, but intimately related elements is critically important for successful risk management. It is important to move beyond the qualitative approach and use quantitative methodologies to measure the financial impact of the occurrence of each major risk. We live in a world where the only constant is change and thus it is not surprising that a bankerÆs life is still governed by assessing, measuring and pricing risk. Banks are attracted to funding well managed companies with strong cash flow projects. But we are more risk averse compared with the credit appetites of late last century. This attitudinal shift has resulted in tougher term sheets for the early 21st century, encompassing more conditions, warranties, undertakings and stronger cash sweep provisions. Banks require well balanced portfolios to achieve an acceptable spread of risk, thus there is a more restricted market for small company lending than that available to large multi-project corporate entities with less concentrated risk profiles. Because of this focus, junior company debt finance remains comparatively expensive and especially so for more challenging geographical and political environments.

Jan 1, 2004

The smelting of the Broken Hill lead concentrates at the Broken Hill Asso,ciated Smelters produced, among other products, approximately 4,900 ounces of gold and 8,800,000 ounces of silver during the year ending June 30th, 1938. The following table shows the actual amounts of gold per ton of lead concentrate produced during this period at the important mines. The total gold in the period is calculated from the number of tons of lead concentrates produced, and by comparison with the production' of silver, shows thatthere is no constant relation between the amounts of gold and silver.The fact that no gold is seen during milling, even when gravity concentrating tables are employed, signifies that the gold does not occur as occasional coarse particles.Further, as the values increase considerably in the flotation slime, it can be inferred that the gold occurs as minute inclusions in one or more of the minerals in the lead concentrates.The four most abundant minerals in the lead concentrate are galena, zinc blende, chalcopyrite, and...

Jan 1, 1940