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The future of the United States (US) mining industry will be affected greatly by recent coal mining disasters. These have resulted in new legislation which will have an impact on mining economic costs as well safety and health of miners. This paper discusses the changes that new legislation and regulations are making to the industry and current research that is producing technologies to make mining safer and will likely impact the future of mining.

Jan 1, 2008

In recent years a number of explosive blends including ANFO, emulsion and watergel products have been used in a variety of ground types and applications. These `standard' explosives' technologies are not new, but out of the uses and applications, have sprung a new generation of tailored explosives that match the ground type and the operating environment. This is in stark contrast to the norm, where various patterns and loading configurations have traditionally been designed to accommodate the explosive. This paper discusses these tailored explosives and the explosives' technology behind why they work. Active tailoring of explosive formulations can save mining dollars while essentially leaving the explosive price unchanged. Tailoring explosives may lead to increased rock breakage, heave, digging rates; lower digging maintenance costs and in some cases replacing earth moving machinery altogether. Tailored explosives may have other benefits such as reduced over pressure compared with standard alternatives. The tailoring of explosive performance generally involves three major methods (other than changing the bulk density and sensitivity): (i) replacing fast burning reactants with slower burning reactants or vice versa; or (ii) leaving the explosive intact and diluting the entire explosive with slow burning or `inert' material; or (iii) changing the concentration of the fuel/oxidiser mix. When tailoring explosives for particular applications, authorising, testing, costing, manufacturing, and delivery systems must also be taken into account.

Jan 1, 1995

High-sulphidation (HS) gold, silver and/or copper deposits are generated in both the epithermal and the upper parts of the underlying porphyry environments over vertical intervals of up to 2 km. The HS deposits are generated in advanced argillic lithocaps, which are products of the absorption of acidic magmatic volatiles by voluminous groundwater systems. Mineralisation styles in HS systems reflect depth of formation as well as the interplay between structural, lithological and hydrothermal parameters. The deep parts of HS systems, at depths of >1000 m, are typified by disseminated copper¦gold mineralisation comprising digenite, chalcocite and covellite in pervasive advanced argillic as well as underlying sericitic alteration. In highly telescoped systems, suchmineralisation may overprint porphyry stocks and associatedquartz-veinlet stockworks. Intermediate levels of HS systems commonlycontain fault-controlled copper-gold mineralisation, typically as enargite in bodies of vuggy residual quartz, silicification and/or massive pyritic sulphide. The shallow parts of HS systems, at depths of The exploration focus is on four principal HS mineralisation styles: 1. copper (eg Chuquicamata, Monywa) or copper-gold (Wafi) in thedeep porphyry-hosted parts of systems preferably, in the case of thelatter, where supergene oxidation is limited and, hence, flotationmay be used for metal recovery,2. copper¦gold-bearing replacement mantos and pipes hosted bycarbonate wallrocks in the deep parts of systems (eg Bisbee),3. high-grade gold in late-stage veins or hydrothermal breccias thatoverprint the intermediate to shallow levels of systems (eg El Indio,Goldfield), and4. large, bulk-mineable gold deposits in the shallow parts of systemsthat were subjected to supergene oxidation, thereby permittingheap-leach treatment (eg Yanacocha, Pierina).To these preferred HS styles may be added the low-sulphidation veinor disseminated gold¦silver mineralisation that is commonplacealongside many HS systems (eg Victoria at Lepanto). * Originally published in the Proceedings of PACRIM æ99,published by The AusIMM.

Jan 1, 2000

By M Ben, P de Donato, M Kongolo

The extensive literature on sulfide flotation indicates that pyrite poorly floats under alkaline condition. Xanthate concentration has a positive effect on pyrite flotation, but above a pH of 11, pyrite seems to be strongly depressed, independently of the concentration in xanthate. In this investigation, aeration and xanthate concentration effects were studied for pyrite flotation conditioned at pH 11 with lime. Results presented in this paper include surface infrared analyses and pulp chemistry measurements which have showed that aeration had a dual effect on pyrite flotation. It induced pyrite surface activation by oxygen, and oxidation of ferrous iron to ferric hydroxides or oxyhydroxides species. It also favoured dissolution of CO2, leading to calcium carbonate precipitation and adsorption onto pyrite surface. Both CO2 dissolution and ferrous oxidation generated protons and decreased pulp pH. Pyrite flotation was observed to be effective with a statistical monolayer of xanthate that could be adsorbed as mixture of dixanthogen and metal-xanthate complex. Non-floated fractions showed high amounts of carbonate, and presence of hydroxyl iron sulfate (Fen(OH)m(SO4)p, xH2O) which have inhibited the hydrophobicity effect of adsorbed xanthate. Environmental desulfurisation could be improved by aeration control causing pyrite oxidation and pH decrease to reach optimal flotation condition with a relatively low xanthate concentration.

Jan 1, 2005

Alluvial gold grades are typically highly erratic. It is very often difficult to establish with confidence the in situ grades of reserve blocks due to the small number of pit or drill hole samples available, and their erratic values. Trends in grade are often obscure. Geostatical methods are inappropriate due to the extreme nugget effect found in alluvial gold field data. Classical statistics appear more suited to such data but require assumptions to be made regarding the nature of the population sampled. Recent developments in computer intensive non-parametric statistical methods provide a new approach to dealing with some of the above problems. These methods avoid making assumptions about the type of population distribution, usually through some kind of re-sampling scheme. The bootstrap procedure involves taking the estimate of interest and synthesising its population of by re-sampling the original data a large number of times (1000+), at random and with replacement. The synthetic population is then used to draw conclusions about the likely behaviour of the true population.

Jan 1, 1985

By Urie R. W

Fluidized bed roasting of copper concentrates from Mt. Morgan, Mt. Lyell, Mt. Isa, and Peko was performed in a 3 ft 6 in diameter, slurry fed, pilot plant roaster operated under autogenous conditions to produce calcines with desirable leaching properties. A 12 in. diameter, externally heated roaster, provided with a dry feed system, was also used.An account is given of important factors which influence roaster behaviour and performance, and the effects of operating variables on calcine composition and leaching properties are described. Due to copper ferrite formation, a maximum of approximately 50 per cent of the copper in the calcines may be in the form of CuO before the copper leach efficiency falls significantly below lOO' per cent. Recovery of gold by cyanidation of leach residues was consistently high and independent of roasting conditions.INTRODUCTIONIn traditional practice copper is produced by pyrometallurgical techniques when the ,copper minerals in the ore or concentrate are predominantly sulphides, and by hydrometallurgy when the minerals are oxidized. Copper smelting is most suited to large scale operations, and for many years small to medium size mines with sulphide orebodies have been interested ill; alternative processes.Since hydrometallurgical plants (ie. leaching and electrowinning plants) are essentially unitized, they may be scaled down in output without much loss in efficiency or increase in processing cost, and many proposals have been made for the application of this type of process following roasting of the sulphides to render the copper soluble. However, until the advent of fluidized roasting, it was not possible to control the roasting operations sufficiently precisely to produce calcines consistently of the required leaching characteristics.

Jan 1, 1961

By G Morgan, C Kemp

In December 2010, a trial of borehole radar technology was conducted to test the usefulness of the technique in better refining the position and geometry of narrow vein orebodies away from the primary data sources of drilling and mapping of development excavations. This paper summarises the reasons why the technique was applied, describes the testing methods selected and summarises the outcomes of the trial.Poor reconciliations of recovered metal from a section of an orebody at Jundee mine site, Western Australia, led to an investigation that identified insufficient understanding of the geometry of a narrow vein orebody as a potential cause. This orebody was situated between mapped development excavations and away from surrounding drill holes. Borehole radar was identified as a possible technique that could supply information on vein location and continuity away from other data sources allowing more accurate orebody modelling and subsequent stope optimisation.A borehole radar instrument (10 - 100 MHz frequency) was inserted into pairs of purpose-drilled boreholes on either side of relatively well-constrained mineralisation and the radar reflection data was collected. This process was repeated in five locations across the mine to represent the most common geological settings, lithologies and orebody varieties encountered at Jundee to determine the suitability of applying the technique in each of these settings. Collected, processed and interpreted radar data was compared to other geology data collected independently for verification and interpretation.Conclusions drawn from the analysis were that the technique could effectively determine the following features of the mineralised veins in the majority of test environments: geometry of veins, magnitude of offsets where structures intersect and orientations of planar structures with short strike length. The technique was very useful in selecting the appropriate structural interpretation where available data could lead to multiple, equally likely, interpretations.CITATION:Kemp, C and Morgan, G, 2012. Using borehole radar to refine orebody interpretations in a narrow vein gold deposit, in Proceedings Narrow Vein Mining 2012 , pp 121-130 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Real F, Carvalho P

During the development of the Neves-Corvo Underground Copper Mine, since 1981, inflow of water has been encountered in the mine workings, which consist of a ramp from surface 5 km long, a shaft 575 m deep and access crosscuts through the massive sulphide orebodies of Neves, Corvo and Graga, which are three of the four known deposits up today. Mine-hydrological studies have established the main characteristics of the hydrological system and its evolution in space and time. In a geological setting of low permeability rocks of Paleozoic age, tectonically affected by thrusts and faults, this has involved consideration of the relation with surface and ground water as a result of mine dewatering processes. The hydrological systems are described and summarized in this paper together with the techniques employed to study their origin and evolution, namely hydrochemistry, thermometry, piezometry and isotopic tracers.

Jan 1, 1988

By J Coward, S Bulatovic

There are currently two operators producing oil from the surface-mineable portions of AlbertaÆs oil sands (Syncrude Canada Ltd and Suncor Inc) and two other companies are proposing to enter the industry (Albian Sands Energy Inc in 2002 and True North Energy LP in 2004). Tailings from the two current oil sands plants contain approximately 220 000 tonnes per year of TiO2 and approximately 80 000 tonnes per year of zircon. This represents approximately six per cent of the worldÆs TiO2 consumption and approximately nine per cent of the worldÆs zircon production. With the commissioning of plants by Albian and True North, and the announced expansion of plants by Syncrude and Suncor, it is expected that these tonnages could quadruple in the next ten years. All of these operators have at least 50 years of reserves even at these expanded production rates. The occurrence of heavy minerals in AlbertaÆs oil sands has long been known and is well documented in the literature. There have been a number of attempts to produce market-grade products from this resource and the results of this work have been quite mixed. Typically, researchers have used the normal mineral dressing techniques of the industry and have found the mineral assemblage does not respond to these techniques all that well. This has led to the widely-held suspicion that there must be some difficult metallurgical problems associated with this resource. There are three main problem areas that have created difficulties for previous researchers:the bitumen coating on the sand grains; secondary mineralisation such as pyrite, siderite and calcite; and a high proportion of aluminosilicates (approximately 25 per cent) that have the same gravity, electrostatic and magnetic properties as other minerals in the heavy mineral suite. Recent work by Lakefield Research shows that these problems can be largely overcome with some novel approaches. The bitumen can be removed by washing with a solvent in the presence of a demulsifier; the pyrite can be removed by flotation; and the titanium and zircon minerals can be separated by selective flotation followed by conventional electrostatic and magnetic separation.

Jan 1, 2001

By Blake W

Based on preliminary computer model simulations and stability analyses, both longi- tudinal and transverse, large dimension, cut- and-fill rooms were designed for the parallel dipping ore layers at Kamoto mine. Full scale testing of the designed rooms showed that the rooms are stable and that the rock behavior is predictable. Ordinary waste rock was selected as the filling material because the fill was found to carry little load.

Jan 1, 1973

By Davidson JR, Napier-Munn TJ, Kojovic T

A research program was conducted to determine the relationship between operating conditions and medium losses in Mt Newman Mining's Beneficiation Plant. It was found that major medium losses were adherence losses and losses fran the overflow from the water recovery cyclones. Operating density and medium blend were found to have a significant effect on the medium consumption. Viscosity was thought to be the underlying factor. This viscosity problem was overcame by adding dilution water to the cyclone spigot discharge to reduce viscosity. The result was a reduction in medium consumption of 25 percent under normal operating conditions. Keywords:- Heavy Medium, Viscosity, Medium Carposition

Jan 1, 1987

The development of the Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves is a significan step towards informing the financial community and the public about the future profitability and risks of investing in resource companies. The Code is also important from the accountants' point of view because it provides them with a well-defined bash for assigning costs or attributing value to the assets of resource companies and hence improving their financial reports. Although reporting to the public is ultimately the responsibility of management, accountants, like geologists, are frequently required to provide information for inclusion in these reports. Jr the last ten years, there has been a considerable refinement in the reporting of mineral resources which can be attributed mainly tc the progress made towards developing the Code. It seems tha the classification and terminology that the geologists have developed are widely used in the annual reports. However, little progress has been made by accountants in improving the financia information. The purpose of this paper is twofold: (a) to outline briefl) some of the major problems in accounting and reporting fo; mining companies and; (b) to examine the potential contribution of the Code in solving those problems.

Jan 1, 1990

By G Hancock, J Lowry, T Coulthard, W Erskine, M Saynor

An important part of planning for the rehabilitation of uranium mine sites is the ability to assess the geomorphic stability of the final landform, over time frames ranging from decades to millenia. Depending on the environmental conditions, erosion features such as gullies may incise into containment structures, potentially leading to the exposure and transport of encapsulated radioactive material. Further, erosion may lead to increased sediment loads and the transport of other mine-related contaminants off-site and into downstream waterways. While erosion may be monitored and assessed over the short term (years to decades), the longer-term behaviour (centuries to millennia) of such landscapes is not within any meaningful human management time frame. Landscape evolution models (LEMs) can provide information on soil erosion rates at decadal or centennial scales over large spatial scales, and evaluate the sensitivity of these processes to environmental changes. However, an important issue associated with the use of models is the ability to assess the reliability and accuracy of the model. In this paper, the CAESAR-Lisflood LEM is tested for its ability to predict soil erosion from a series of 30 m × 30 m experimental plots specifically constructed for this purpose on a trial rehabilitated landform at the Ranger Uranium Mine in the Northern Territory, Australia. Model predictions of bedload and suspended sediment loads from the erosion plots were compared with field measured observations collected over four wet seasons from the trial landform. Once calibrated for the specific site hydrological conditions, the predicted sediment yield – specifically, bedload – demonstrated an excellent correspondence with the field data. However, longer-term simulations of ten years identified an exhaustion effect in sediment yield from the landform. These latter results indicate that a weathering function needs to be incorporated into CAESAR-Lisflood to ensure confidence that the CAESAR-Lisflood LEM will be able to correctly predict the long-term evolution of a rehabilitated landform once it has been?constructed.CITATION:Lowry, J,?Saynor, M,?Erskine, W, Coulthard, T and Hancock, G, 2014. A multi-year assessment of landform evolution model predictions for a trial rehabilitated landform, in Proceedings Life-of-Mine 2014 , pp 67–80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By M Fewings

This paper casts a light on the sometimes murky world that lies between base metals product æout the gateÆ, and money in the bank. Whether your base metals are leaving the mine as a refined product, or as an ore or concentrate, the generally accepted method of value determination is a London Metal Exchange price, usually measured at some point after the material has left your control. In this paper, the structure and operation, regulation and the reasons for the use of the London Metal Exchange are explored. In addition, the risks and opportunities that terminal market pricing provides to mine managers are explained, with particular reference to hedging. The paper also deals with the structure of the sales contract, including management of shipping issues, agreement of delivered quality, documentation and administrative issues. The selection of counterparties, the role of traders in the market and the growing influence of China and India as base metal consumers and competitors are also addressed.

Jan 1, 2006

By Bailey S, Avraamides J

Laboratory-scale experiments were conducted in a mechanically stirred aeration vessel to determine the rusting abilities of aerated water in the presence of various catalysts compared to the industrially used ammonium chloride. The catalysts used were tartaric acid and citric acid, firstly by themselves, and then in later experiments mixed with ammonium chloride. From these experiments it was found that leaching of iron from reduced ilmenite in the presence of either tartaric acid or its sodium salt was much slower than in the presence of ammonium chloride. Citric acid or its sodium salt also give a slower rate of leaching than the ammonium chloride system, but citric acid and its sodium salt mixed in equal proportions produced a rate of leaching approximately twice as fast as the standard ammonium chloride system. When tartaric acid was mixed with ammonium chloride the leaching rate was found to be equivalent to the leaching rate of the same amount of ammonium chloride alone, thus indicating that tartaric acid made no contribution to the leaching in this svstem_

Jan 1, 1996

By C McGuire, W Harris, S Arsenault, D Witow, B Rogers

Mining deep orebodies is increasingly becoming the norm as the ‘easy’ orebodies are depleted. Deep ore mining requires significant ventilation and cooling infrastructure to not only meet regulatory requirements for air quality but also to achieve acceptable workplace temperatures with the higher strata rock temperatures and increased auto-compression. At the same time, advances in battery equipment technology are turning the possibility of a battery powered fleet into reality. The switch from a diesel fleet to a battery powered fleet offers several positive opportunities for the design and operation of a deep mine.The potential to reduce ventilation and cooling requirements due to battery powered equipment results in significant cost savings for mine development and infrastructure. Battery powered fleets are not subject to the same dilution requirements associated with diesel fleets thus allowing lower ventilation rates. At the low ventilation volumes possible with a battery powered fleet, surface refrigeration plants are limited with respect to the amount of cooling that can be delivered to the workface. Considerations for calculating the optimum air flow and cooling requirements are presented. Considerations for locating the refrigeration plant are also discussed. This paper presents these opportunities and considerations; including a case study comparing the ventilation and cooling system design with a diesel fleet versus battery fleet for a planned mine in Northern Ontario, Canada.CITATION:Harris, W, Arsenault, S, McGuire, C, Rogers, B and Witow, D, 2017. Diesel to electric – creating a positive paradigm in underground ventilation and cooling, in Proceedings Australian Mine Vent Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

The Dizon open pit mine of Benguet Corporation in western Central Luzon, Philippines has yielded some 182 000 t copper, and about 26 000 kg gold and 48 000 kg silver as by products since it started operation in November 1979. The 140 million tonne orebody is associated with a small quartz diorite porphyry stock emplaced in volcanic rocks on the basal slope of a stratovolcano complex as stockworks, fracture fillings and disseminated sulphide mineralization averaging 0.43% Cu, 0.93 g/t Au and 2.5 g/t Ag. Intense hydrothermal alteration accompanied the mineralization that developed fairly distinct mineral assemblages within and around the intrusive. Post-ore volcanic activity later gave birth to an upward-flaring diatreme which broke out south of and adjacent to the orebody and partially destroying it. Subsequent volcanic activity buried the mineralized area along with the rest of the stratovolcano's surrounding slopes under a thick deposit of pyroclastic and laharic debris. Erosion eventually removed the volcanic cappings over Dizon and also exposed the quartz diorite porphyry stock which might have resulted in the truncation of a sizeable section of the Dizon deposit. The chain of stratovolcanoes that comprise southeastern Zambales range hugging the southeastern edge of the Zambales ophiolite is part of a west-facing volcanic arc that extends for some 300 km along the western margin of central and southern Luzon whose development has been correlated to the subduction in the Manila Trench located off the west coast of Luzon. Prominent WNW-trending lineaments that cut across the ophiolite appear to be splays of the Philippine Fault whose intersection with the Mt. Pinatubo stratovolcano complex might have localized the emplacement of a number of intermediate stocks along with the gold-rich porphyry copper mineralizations associated with some of them.

Jan 1, 1987

The New Zealand microcontinent is relatively well endowed with gold deposits; its past gold production per unit area of 3.2 kg/km2 ranks high on a world scale. Total recorded production (1857 - 1986) is about 854 000 kg and most of this gold was mined between 1861 and 1920. There has been a strong revival in gold exploration and mining since 1979, with exploration expenditure of around $15 million per annum and a declared gold production in 1986 of 1265 kg (886 kg in 1985). In addition to numerous alluvial gold recovery plants working small to medium sized deposits (mainly in Westland and Otago), there are five medium to large projects that have started production (Martha Hill), or have reached advanced stages of construction (Grey River dredge), permitting (Golden Cross and Macraes) or exploration (Globe-Progress). This summary paper is taken from reviews by Brathwaite et al (1986) and Brathwaite (1988).

Jan 1, 1988

The Gympie Province is a unique tectono-stratigraphic unit which does not fit into the overall palaeogeographic pattern of the New England Fold Belt (NEFB), and part of it has been proposed as an exotic terrane more closely linked to New Zealand. From E to W the Gympie Province comprises 6 distinct units which can be evaluated as suspect or exotic terranes.

Jan 1, 1990

The Tregoora Gold Project is centred around the old Mitchell River Antimony Field located 100 kilometres west-northwest of Cairns, North Queensland. The project is currently the subject of a joint venture between Strategic Minerals Corporation N.L. and Hawk Investments Limited.Historical BackgroundThe Tregoora area was first prospected for antimony and gold around 1890. During the periods 1905 to 1914 and 1937 and 1944 approximately 100 tonnes of antimony and an unknown quantity of gold were won from a number of small mines the principal one being the "Retina". A strong increase in the demand for antimony in the early 1970's resulted in renewed exploration activity in the region and the re-development of the Retina Mine. Despite the intermittent interest in the region for antimony it was not until 1984 that the potential of the area for hosting gold resources was realised with the delineation by Strategic Minerals Corporation N.L. of a significant gold deposit now referred to as the Black Knight.

Jan 1, 1986