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Vitrinite reflectance forms the basis of a study of coal rank variation in two areas of the Upper Hunter Valley, New South Wales, on the northern margin of the Sydney Basin. A selective analysis procedure, based on samples rom twenty-two boreholes, has resulted in a small range of reflectance values for each sample and consequently a high degree of significance for calculated mean values. The patterns of rank distribution derived from these data have facilitated an interpretation of the rclative timing of coalilication and deformation in each area.This study provides support for the suggestion by several authors that there were at least two periods of folding in the tJpper Hunter Valley. In the Hebden-Ravensworth area, minor folding took place after most of the coalilication was completed.To the west, in the region of the Muswellbrook Anticline, coalification occurred during or after the formation of this major structure. Tectonic instability during deposition of the Singleton Super-Group, in the region of the Hunter-Thrust on the basin margin, is evidenced by rank variation suggesting differential subsidence across this zone.

Jan 1, 1980

By Martin B. Hudson, Daniel Brescia, Zhangwei Ning

Due to the complexity and sensitivity of surrounding environments, instrumentation and monitoring (I&M) is critical for many urban deep excavations. The objects to be monitored include shoring bulkheads, retained embankments, adjacent buildings and roads as well as underground utilities. However, there are also plenty of constraints on the implementation of I&M such as: congested site space, difficult access to instruments, coordination among multiple contractors, and installation permits for private or public properties. Because of these constraints, sometimes the implementation of the initially planned I&M is delayed, its scope is reduced, and/or the continuity of monitoring is interrupted. For these reasons, it is important to implement the I&M with robust and redundant capabilities while providing minimal interference to the project construction and schedule. This paper describes state-of-the-art I&M technologies including automatic motorized total station (AMTS) with camera and automatic leveling device, reflectorless AMTS and IoT- based wireless sensors based on a case study of an on-going deep excavation project. INTRODUCTION In urban environments, deep excavations requiring the construction of temporary shoring bulkheads are becoming increasingly common, with the associated need to provide protection of the surrounding built environment during construction. Protection of the surrounding environment requires planning, engineering, construction, monitoring, and excessive shoring movement mitigation. The I&M is a vital component of the deep shoring implementation. In public projects, geotechnical I&M is often placed within the general contractor’s scope, whereas the majority of deep excavations are privately undertaken. For those private developments, sometimes the developer contracts the geotechnical I&M directly with the project geotechnical engineer or by a geotechnical I&M specialist hired by the project geotechnical engineer. In either the public project or private development case, the effective deployment of the I&M system relies heavily on coordination and collaboration with the project contractor.

Jan 1, 2018

By A. G. Mayton

Vehicle vibration exposure has been linked to chronic back pain and low back symptoms among agricultural tractor drivers. The objectives of this study by the National Institute for Occupational Safety and Health (NIOSH) were to assess driver whole body vibration (WBV) exposures and recommend interventions to reduce the risk of back related injuries, particularly relative to vehicle jarring/jolting (the transient mechanical shock components of WBV). The methodology included collecting, from two independent samples, ?eld data and health and work history data of farm equipment operators. Data were collected during mowing, raking, baling, chiseling, tilling, and road travel for different model tractors. Spraying using a sprayer and shrub removal with a skid steer loader were also included. Based on ISO 2631 (1985), the American Conference of Governmental Industrial Hygienists, threshold limit values, presents 0.5 m/s2 as the action level recommended by the Commission of European Communities for overall weighted total RMS acceleration (vector sum for axes x, y, and z) [ACGIH, 2006. Threshold limit values and biological exposure indices. Cincinnati, OH]. WBV measured at the operator/seat interface exceeded this action level. The roughest rides and highest vector sum accelerations occurred with small utility tractor mowers (3.3 and 2.8 m/s2) and a skid steer loader (1.7 m/s2). Major ?ndings from health and work history data showed 96% of participants reported having to bend or twist their necks, although 24% reported neck symptoms. Sixty four percent of participating operators reported experiencing back symptoms (e.g., pain, aching, stiffness, etc.). Recommendations included: specifying a seat that ??better?? isolates operators from jars/jolts with new tractor purchases; maintaining the seat/seat suspension and replacing worn or damaged cushions with NIOSH tested viscoelastic foam padding; using larger diameter tires with radial ply instead of bias ply construction, particularly on small utility tractor mowers, to aid in attenuating ride ??roughness??; using a swivel seat to reduce the stress on the neck from bending or twisting; and improving efforts to educate owner/operators of the adverse effects of WBV exposures. Since the data presented in this paper were collected from two independent samples, the authors were unable to draw any correlations or etiological inferences from the study. However, results were compared and contrasted with other studies which included similar vibration measurements in agriculture.

Jan 1, 2008

By Moresby J. F

Segregation roasting was used to recover more than 85 per cent of copper from crushed, minus 14 mesh refractory furnace-lining bricks. A plus 14 mesh fraction: which was high in copper, could be recycled directly to the smelter, giving an overall recovery of approximately 90 per cent. An oxidation roast at about 700°C was necessary, before segregation roasting, to convert copper sulphides and copper metal to sulphates and oxides. Withsegregatron temperatures in the range 600°-650°C the quantities of solid carbon and NaCI required are 2-5 per cent and 1 per cent respectively. P.V.C. coating from scrap copper wire can be used instead of NaCl as asource of hydrogen chloride for the segregation reaction.

Jan 1, 1978

By James Ransford Dankwah

This work investigates the effect of waste plastics addition on the reduction of iron oxide by sawdust. Composite pellets of iron oxide containing sawdust (SD), high density polyethylene (HDPE) and blends of SD/HDPE were fired under argon in a horizontal tube furnace at temperatures between 1300 and 1500 °C. Reduced samples were weighed after 10 minutes of reduction and the extent of reduction was calculated from the measured oxygen contents of the compact. The results showed improved extent of reduction when SD was blended with HDPE. The highest extent of reduction was achieved at SD:HDPE ratio of 2:3.

Jan 1, 2014

There are many ways to classify structural slurry wall elements, but the DFI committee chooses to limit these descriptions to three functional requirements, namely: design function, plan configuration and type of panel reinforcement. (See Figure 1 in Part IV for panel classification). Slurry walls can function as: 1. Curvilinear or linear elements for temporary and/or permanent structures to resist lateral forces transferred from the ground, water, earthquakes and various surcharge loads. 2. Load bearing elements in various plan shapes to resist vertical forces. 3. Combination Elements to resist combined forces under conditions 1 and/or 2. For example, elliptical shafts with various openings for tunnels and conduits have been commonly used for deep excavations.

Jan 1, 2005

By D. E. Kirby

The electrochemical reduction of AlC13 was investigated as a process for the production of aluminum. An externally heated, single-compartment cell with a rammed refractory lining was used with molten KCl-NaCl-AlC13 electrolyte. Aluminum was deposited qt 700° to 760° C with a current of 100 to 200 amperes on a molten aluminum cathode. Chlorine was evolved at a graphite anode and collected and measured to provide a quantitative evaluation of the AlC13 reduction. Aluminum was removed from the cell by siphoning or ladling. Granular AlC13 was added periodically to replenish that depleted from the electrolyte. Concentrations of 7.5 to 17.5 percent AlC13 in the electrolyte were optimum for operation. Anode current efficiencies of 83 to 85 percent were attained, using anode current densities of 5.9 amperes per square inch and an anode-cathode distance of 4 inches. The chemically bonded, alumina liner was resistant to attack by aluminum and chlorine but susceptible to erosion at the surface of the electrolyte. Titanium diboride proved suitable for the electrical connection to the molten aluminum cathode. Aluminum of a purity equal to or better than 1100 series metal was electrowon continuously from commercial AlC13 for a period of 4-1/2 months.

Jan 1, 1970

Train services through the Channel Tunnel linking Britain and France where scheduled to be fully restored in February 2009 following several months of repairs after a major fire in the tunnel on Sept. 11, 2008. A lorry caught fire on a shuttle train carrying heavy goods vehicles bound for France through the 50-km- (31-mile-) long northern tunnel. The fire, that spread to other vehicles, raged for about 16 hours. The extreme temperatures of up to 1,000º C (1,832° F) caused extensive damage to about 600 m (2,000 ft) of the 7.6-m- (25-ft-) diameter tunnel?s concrete lining, approximately 11 km (7 miles) in from the French entrance. The Channel Tunnel operator, Eurotunnel, awarded the repair con-tract, estimated to be between ?50 to 60 million, to a consortium of Freyssinet, Eurovia Travaux Ferroviaires (ETF) and Vinci Energies. Freyssinet was appointed to look after the civil engineering works, while ETF would be responsible for track and overhead wire restoration and Vinci Energies responsible for other equipment. The technique of hydrodemolition, which uses high-pressure water jets to remove concrete from various structures, was specified as the method to remove the fire damaged concrete. Freyssinet subcontracted the concrete removal to the specialist hydrodemolition and industrial cleaning contractor Philip Lasserat.

Jan 1, 2009

By Zhuo Chen, Jun Zhou, Jiemin Zhou

Samples of the reacting suspension particles were taken from the reaction shaft of a commercial flash furnace at different heights. The processes of matte and slag formation and morphology of the samples in the shaft were observed and analyzed. Variations of matte and slag composition in the shaft were investigated. By analyzing the samples taken from the settler at different locations, settler processes were studied such as slag formation, agglomeration and separation of matte-slag phases, Fe3O4 reduction, copper-in-slag reduction etc. In accordance with the characteristic of matte and slag formation the flash furnace can be divided into 6 functional regions, and a mechanism model called as “Micro bath process” is proposed for matte and slag formation in a commercial flash furnace. INTRODUCTION During flash smelting, concentrate particles scattered in the reaction shaft complete their oxidation reactions in suspension. The droplets produced fall into the settler beneath with a small amount of un-melted solid particles, agglomerate and separate into matte and slag layers which are tapped out from their tap holes separately. With respect to the extent of slagging reaction in the reaction shaft, there isn’t any commonly accepted understanding in literature (Kimura, Ojima, Mori & Ishii, 1986; Kemori & Kondo et al.,1988; Kemori, Denholm & Kurokawa, 1989; Fagerlund &Jalkanen, 2000). Some assume that the slagging reaction in the shaft can be ignored and some propose that all slag is produced in the shaft. With regards to the characteristics of the physical-chemical changes of concentrate particle in the reaction shaft, although there are some research results reported from pilot scale and commercial scale experiments (Kemori, Ojima & Kondo, 1988; Hagni, Vierrether & Sohn, 1988; Jorgensen, Taylor, Dickinson & Stevenson, 1992; Swinbourne, Simak & Yazawa, 2002; Kivinen & Tuominen, 2005), they are generally limited themselves to theoretical analysis and calculations. No studies are published concerned with the processes of matte and slag generation in the shaft, quantitative analysis of the processes, variations of matte and slag composition and morphologies of the melts along the axis of the shaft, etc.

Jan 1, 2019

Support design in jointed or blocky rock masses is often approached by the use of either 'rules of thumb', rock mass classification systems such as the Q-system (Barton, Lien and Lunde, 1974) or RMR (Bieniawski, 1973) or conventional wedge analysis. Generally, this requires that a number of key simplifying assumptions are made and the support system is designed to cater for either a mean, most likely, or worst case scenario depending on the risk tolerance. The design block size is often a major uncertainty and often a worst case block size based on excavation span is used. Thompson and Windsor (2007) state that it is inappropriate to base support designs on the excavation size as these size blocks rarely occur if discontinuity trace lengths are considered. Probabilistic keyblock methods can be used to determine the most likely design block sizes. A methodology is presented whereby JBlock software (Estherhuizen, 1996) is used to estimate potential block sizes as part of the support design process. Using information such as the spacing, orientation and length of discontinuities, it is possible to simulate blocks in the walls of an excavation (Esterhuizen and Streuders, 1998). Keyblock analysis methods (Goodman and Shi, 1985) are used to evaluate whether blocks are removable and whether the chosen support will be sufficient to ensure stability. Data from two mines is used to demonstrate how probabilistic keyblock analyses can be used in support design. Discontinuity data was used to generate 10 000 removable blocks and the design block size statistics were determined. For one mine this information was used to scale blocks in a conventional. Unwedge analysis whilst for the other mine, the point estimate method (Harr, 1987) was applied. The choice of appropriate design acceptance criteria in terms of factor of safety and probability of failure is also considered.

Nov 25, 2010

By F. -J. Wodopia

Sustainability of energy supplies has been an issue of general interest for a long time. Whilst in the past the continuous productive use of natural commodities was in the fore, its compatibility with the environment and climate and ultimately also social aspects have recently gained more and more attention. Today many discussions focus on the climate compatibility of individual options to act. Fossil fuels, in particular coal and lignite, are generally challenged because coal use makes a significant contribution to global man-made CO2 emissions. The drastic increase in the consumption of fossil fuels is not explained by the fact that coal utilisation technologies are not or cannot be sustainable but rather by the growing world population and the endeavours numerous national economies trying to catch up economically. Coal is the world’s No. 1 fuel and, in the view of many experts, will keep this position also in the foreseeable future. The access to its deposits plays a significant role for the economies of the emerging countries. Consequently the aspects of energy security and economic efficiency need to be considered at eye level with climate compatibility. In Germany, however, the public acceptance of fossil fuels and of large industrial projects is in the focus of attention.

Jan 1, 2011

By M A. Lund, C D. McCullough

In Australia and worldwide, open cut mining has become increasingly common over the last few decades through changes in excavation technology and ore economics. However, such operations frequently leave a legacy of open mine pits once mining ceases. Pit lakes will then form in mine pits that extend below the water table when dewatering operations cease. Pit lake waters are typically contaminated with metals, metalloids, saline or acidic/alkaline and rarely approach natural water body chemistry. Physically, pit lakes have unique bathymetries, are often strongly wind sheltered and have very small catchments. Nevertheless, pit lake waters often constitute a vast resource but of limited beneficial use (due to water quality issues); with a potential to contaminate regional surface and ground water resources. Water in pit lakes has the potential to be useful for a range of purposes in the Australian context of characteristic hot, dry climate and relatively few natural water bodies. Consequently, pit lakes can be seen to represent either a significant liability or a water resource to mining companies and regional communities. However, the lack of knowledge on pit lakes continues to hinder their proper management. This paper summarises the limited information currently available on water quality associated with Australian pit lakes. Information on pit lake occurrence, distribution and water quantity and quality is not nationally collated and requires immediate and ongoing attention from both mining companies and regulating authorities. Lack of a readily available database for pit lake occurrence, distribution and water quality fails to realise the potential for these water resources by both mining companies and Australian communities. Lack of access to pit lake quantity and water quality data may also lead to failure to manage this significant source of mining environmental risk.

Jan 1, 2009

By W. Barnett

The Limpopo Metamorphic Belt is a complex geological terrane with at least three major deformational events. Tectonically juxtaposed lithology, open to isoclinal folding, crosscutting and re-activated shear zones and metamorphic gneisses and schists make pit slope design and maintenance a risky business. Venetia diamond mine?s Cut 3 is planned to reach 360 m by 2011. The difficult rockmass created problems in the original pit and a new more comprehensive slope design was necessary. Nearly 9 km of geotechnical drilling were undertaken to produce a new geological model and provide geotechnical information near the final Cut 3 face. All existing data from the pit were brought together into a database. SRK Consulting were brought into the project to audit the process and provide most of the manpower for the data analysis. Existing failures were back-analysed and the geotechnical domains identified. Analyses of only the southern domains are discussed in this paper. Geotechnical engineers can design slopes at any angle, but it is up to the managers at the mine to decide what risk they are willing to accept in a slope design. Once the issue of risk was discussed and settled in respect of the consequences of failure, each of the main geotechnical domains were analysed to produce a slope design at5% probability of failure with 15% above the first ramp. A risk assessment of the design was then undertaken to determine what risk the design placed on the equipment, personnel and the profitability of the overall mining operation. The risk assessment indicated minimal risk to the operation. One of the main assumptions of the final design is that the pit slopes will be dewatered. A project was immediately put in place to determine a groundwater model for the mine and to thereby determine the best dewatering procedure. However, it should be obvious that it is practically impossible to prevent benches from getting briefly saturated with water during storm conditions. It was therefore necessary to look specifically at supporting the crests of the ramps in the problematic southern domains to guard against the possibility of crest failure during heavy rains. The data available were re-analysed toward this objective. Spiles were recommended as the most cost-effective support system, and a probabilistic approach was used in the design. The final design has a 5% probability of failure, and the analyses indicate a strong sensitivity of the required spile spacing to the strength of the reinforcement material that will eventually be used. The pit slope parameters derived as per the discussion in this paper have just begun to be implemented at Venetia Mine.

Jan 1, 2001

THIS bulletin presents all analytical and lest methods regularly used by Bureau of Mines laboratories for characterizing coal and coke. To provide better service to coal producers and consumers, the scope of this bulletin has been expanded to include important test methods used to evaluate coal properties for commercial processing. The methods described will prove valuable to all persons interested in analyzing and testing coal and coke.

Jan 1, 1967

By Daniel P. Lathrop, Leslie C. Taylor, William L. Fourney

Except when the target is on the surface, e.g. a tank track, the most important loading mechanism from a buried charge on a target above it is the impact of soil propelled at the target by the expanding gas from the explosion. Detonation of a shallow buried explosive generally yields an unstable interface between the rising soil and the air which appears to be the result of Richtmyer-Meshkov instability. Irregular “fingers” of saturated sand extend into the air above a more generalized dome of soil. These fingers move at a much higher velocity than the material between them at smaller stand off distances. As a result, the local load on the target at positions on the target at the same distance from the charge may vary by 50% or more from shot to shot or even within a single shot. This variation requires a large design safety factor to assure the integrity of design of mine-resistant vehicles.

Jan 1, 2009

By Horst Pöchhacker

The largest structure along the Tauern highway section between Salzburg and Villach is the 6.4-km-long Tauern Tunnel. The major geotechnical problems that came up surprisingly while driving the headings of that tunnel and their successful solution form the content of this article. A detailed discussion is presented of the special construction methods developed by systematic application of the principles of the New Austrian Tunneling Method with which even very heavily squeezing ground with large excavation areas can be mastered reliably and economically.

Jan 1, 1976

By F. W. Wood

ORIGINAL experimentation in specially designed arc-melting furnaces and a comprehensive review of technical literature have helped with an understanding of electric arcs as used in metallurgical applications. Results relevant to the distribution of electric potentials and currents, temperatures, pressures, the consumption of electrodes, the identities of particles participating in electrical conduction, and the modes and mechanisms of discharge are presented and discussed. Present knowledge of high-current arcs is insufficient to test pertinent theoretical suggestions. However, the chief doubts concern the identities and the liberation or formation of current-carrying particles. It seems that either (1) novel formulations of existing concepts are needed, or (2) essentially new concepts must be recognized to explain observations. An analysis of the situation has led the authors to favor the latter possibility and to suggest the existence of supplementary conducting particles. The conduction of current by the streaming of charged agglomerates is postulated. Another outgrowth of analysis is an equation for the arc potential as a function of current densities in the arc. In lieu of conclusions, the potentialities of practical applications and specific needs for fundamental clarification are summarized.

Jan 1, 1965

By M. S. Prithvi

Over the decades, mine and mineral processing plant operations for the most part, have been found to have had adverse impacts on the environment. At the same time, mineral processing and mining operations produce mineral products that are indispensable to modern society. Thus, the sector has desirable and undesirable attributes simultaneously. The situation presents itself as a contradiction (i.e.) the mineral processing and mining operations are wanted by society, and at the same time unwanted by society. The existing methods of addressing the issues raised above have evidently not been very successful in reducing the opposition to new projects and to the related activities such as land acquisition. This paper attempts to show the relevance and applicability of TRIZ for addressing the issue. TRIZ, or Teoriya Rezheniya Isobretatelski Zadach, is a Russian acronym meaning Theory of Inventive Problem Solving. TRIZ is a powerful tool that can be usefully applied to resolve such contradictions, using resources usually available within the system of interest. Accordingly, this paper introduces the issue background, followed by an introduction to some key concepts of TRIZ such as the 40 principles, separation principles and directed evolution. The paper goes on to apply the 40 principles to two case studies. The results show that TRIZ could be a useful tool to generate potentially innovative and sustainable approaches. Its most appropriate position would be as a supplement to current decision-making procedures, and as a validation tool to review existing solutions for possible improvements. Keywords: minerals, environment, TRIZ, contradiction, resources

Sep 1, 2012

By P. J. Sylvester, D. H. C. Wilton, R. I. Wheeler, M. A. E. Huminicki, D. Evans-Lamswood

"Systematic characterization of the mineralogy of massive sulfide ore deposits can provide valuable insights into ore genesis and metallurgical processing that would not be apparent otherwise. We describe a method wherein (1) normative mineral abundances are calculated from whole-rock chemical assays using an algorithm, (2) the results are cast in block models, (3) the results are then verified with automated image analysis of a subset of samples prepared as grain mounts by backscattered electron imaging and X-ray mapping on a scanning electron microscope, and (4) those verified results are integrated with textural data determined by optical microscopy.The technique is applied to the magmatic Ni-Cu-Co sulfides of the Ovoid orebody, based on geochemical assays of 3175 whole-rock samples. Three principal ore zones are defined in the Ovoid. Type I ore occurs in the center of the deposit; it is magnetite-rich and pyrrhotite-poor with intermediate contents of pentlandite and chalcopyrite. Type II ore surrounds Type I ore and is pentlanditechalcopyrite- rich with intermediate contents of pyrrhotite and magnetite. Type III ore occurs at the base and along the outer periphery of the northern part of the orebody; it is pyrrhotite-rich and chalcopyrite- poor with an intermediate content of pentlandite, and a low-to-intermediate content of magnetite. La caractérisation systématique de la minéralogie des gîtes de sulfures massifs peut fournir des indications précieuses sur la genèse des minerais et le traitement métallurgique qui ne seraient pas disponibles par d’autres méthodes. Nous décrivons un procédé par lequel (1) un algorithme est utilisé pour calculer l’abondance de minéraux normatifs à partir d’analyses lithogéochimiques, (2) les résultats sont exprimés dans des blocs diagrammes, (3) les résultats sont par la suite validés par analyse d’image automatisée sur un microscope électronique à balayage en électrons rétrodiffusés et par cartographie en rayons X sur des échantillons constitués de grains montés en résine, et (4) les résultats de cette validation sont combinés aux données texturales obtenues par microscopie optique.Cette technique est appliquée aux sulfures magmatiques de Ni-Cu-Co du gisement Ovoïde, en utilisant les analyses géochimiques de 3175 échantillons de roche totale. L’Ovoïde comprend trois types de minerai. Le type I est situé au centre du gisement; il est riche en magnétite et pauvre en pyrrhotite avec des quantités intermédiaires de pentlandite et de chalcopyrite. Le minerai de type II entoure le minerai de type I et est riche en pentlandite et en chalcopyrite avec des quantités intermédiaires de pyrrhotite et de magnétite. Le minerai de type III se trouve à la base ainsi qu’à bordure externe de la partie nord du gisement; il est riche en pyrrhotite et pauvre en chalcopyrite, avec un contenu intermédiaire en pentlandite et une quantité faible à moyenne de magnétite."

Jan 1, 2012

By J. R. Kastler

It becomes my pleasant duty to call the meeting to order. This is our fiftieth regular meeting. And the session we are opening today, I am sure: will be as interesting and informative as those in the past. These gatherings present a fruitful opportunity for an exchange of experiences and ideas that will aid all of us in our work in the various segments within the coal industry. Walter Johnson and his Program Committee have arranged a wonderful program for us; Walter, due to his standing in the industry and his large acquaintanceship with the leaders of the industry, has really gone to town in bringing outstanding speakers and personalities to deliberate with us in our proceedings. A lot of things have happened since we last met; in the operating end, and in safety we have made marvellous headway, but we have slipped badly in the marketing end. However, I am sure the messages and discussion you will hear will point out ways and means of overcoming at least some of our difficulties. Before we get on with the program, I want to thank our hard working Secretary, Fred Whiteside, who, by the way, is a charter member of the Institute and has attended every one of the fifty meetings we have held; and the various committees who have been meeting for the past several months and who have arranged this fine program you are to hear. I hope all of you enjoy the convention; the business as well as the social sessions.

Jan 1, 1954