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By J. A. CoRGAN, J. A. DECARLO

The coal -carbonizing industry is recognized as one of our country's most essential industries , and this position has been achieved through its primary function as a source of supply of special fuels and chemical raw materials . When coal is carbonized at high temperatures in slot - type coke ovens in the absence of air , it decomposes into two main products cokę ... and crude gas . Of these , the more important is coke , a hard, strong, porous solid that remains in the oven after the volatile matter in the coal has been driven out by heat . The hot crude gas carries with it all. of the coke -plant products except coke and has a complex composition in the vapor: state . Its processing , to produce the four principal coproducts of coke (tar , ammonia , light oil, and gas ) , is accomplished by preferential condensation and absorption . Although the principal coproducts of coke tar , ammonia , and crude light oil - - gas, are of secondary importance , their

Jun 1, 1949

By Michael Samis

The real option valuation method is often presented as an alternative to the conventional discounted cash flow (DCF) approach because it is able to recognize additional project value due to the presence of management flexibility. However, these two valuation methods can be separated on a more fundamental level by their differences in risk discounting. Real option valuation applies the risk-adjustment to the source of uncertainty in the cash flow while the DCF method adjusts for risk at the aggregate level of net cash flow. This seemingly small difference is the reason why the real option method is able to differentiate between projects according to each project?s unique risk characteristics while the conventional DCF approach cannot. This paper provides an overview of the real options and DCF valuation frameworks and discusses the differences in risk discounting that exist between the two methods. Using grade-school mathematics, this paper clearly demonstrates how, with real options, a unique project risk discount can be calculated which is directly linked to the project?s unique risk profile. It also highlights why the DCF method fails in this regard and shows why a call to ?increase the Risk-Adjusted Discount Rate? is an incomplete solution at best. Finally, a heap-leach project and satellite reserve development project are valued with both techniques and the difference in investment conclusions is explained in terms of the risk-discounting concepts discussed here.

May 1, 2003

By Paul J. Sabatini

Between 2008 and 2009, more than 6,000, 23-m long deep mixing method (DMM) elements were constructed to support 124 concrete mats comprising the foundations for the process trains for an LNG facility. The Owner requested first-of-its-kind analyses and assessments to confirm the quality and reliability of the DMM foundation. This paper provides information on these assessments and the procedures used to ultimately conclude that a fit-for-purpose foundation system was constructed. During early phases of construction, several DMM test cores revealed nodules of unmixed clay in upper core samples. A comprehensive review of available DMM core information was undertaken. It was concluded that the amount of coring being conducted as part of the contractor?s QA/QC program should be increased to achieve a foundation system with the required level of reliability. Three-dimensional finite element analyses were completed considering various distributions of defects in the DMM elements and the effects of potential downdrag on DMM elements. Calculated mat settlements and mat stresses were compared to cases without defects in the DMM elements. Various distributions of loaded and unloaded mat areas and number and position (both in the subsurface and laterally) of defects were considered. Four (of the 124) mats were identified as potentially ?at-risk?. The settlement performance of these mats is currently being monitored and, to date, performance has been acceptable.

By R. K. Netolitzky

The Weedy Lake, Tower Lake, and Wedge Lake gold deposits illustrate contrasting styles and different ages of mineralization within the same district. The discovery of these deposits was the result of systematic exploration of gold occurrences noted during research of assessment files. The Weedy Lake and Tower Lake depo its reflect a late-stage gold mineralizing event. The e deposits developed along the same major structural break, and also display simi lar mineralogy and alteration patterns. Mineralization is developed in all the lithologies present. The Wedge Lake property, while having occurrences similar to the Weedy and Tower deposits. has the more important Twin Zone which best fits a volcanogenic exhalative model. The Twin Zone has a complex structural history without a recognizable alteration halo. The setting may be proximal to a hydrothermal vent. Mineralization is hosted within a mixed ulphide/oxide/silicate facies iron formation breccia. and the gold is intimately associated with arsenopyrite. The origin and age of the brecciation is key to understanding the mineralizing event. Traditional prospecting procedures in conjunction with conventional B-horizon soil geochemistry were instrumental in the Twin Zone and Weedy lake disco,•eries. Tower Lake was a prospecting discovery partially defined by previous drill programs. This deposit was also identified by B-horizon oil sampling.

Jan 1, 1986

By S Azam

Coal is a vital energy source and source of carbon for metallurgical applications, contributing significantly to the world economy. Coal mining and processing involve multiple processes that generate Respirable Coal Mine Dust (RCMD), one of the primary sources of health hazards for coal workers. Since 2000, the rate of Coal Workers’ Pneumoconiosis (CWP) has continually increased in the U.S, with severity of the cases also worsening. Increasing evidence shows that exposure to RCMD in coal workers is a high-risk factor for lung cancer, which causes more deaths than the following three major cancers combined in the US Recent observations show an increased incidenceof CWP or other lung diseases, particularly among young miners in the Appalachian basin. The CWP prevalence in Appalachia is four times higher than the national average. Although various regulations are in place, the resurgence of such disease among coalminers demands additional efforts to better understand all the possible facets of coal dust toxicity, taking insights from current interdisciplinaryresearch efforts. One such important field is the interaction of coal dust with moisture in underground mines. Although moisture is prevalent and dynamic in an underground mining environment, it has never been evaluated for its impact on modifying the toxicity of coal dust and transport or flow behaviour. However, research conducted in atmospheric sciences in the past decade makes it clear that moisture in the atmosphere can significantly alter the behaviour of mineral dust. This paper is a part of research aimed at understanding how moisture interacts and alters the characteristics of coal dust. Such insight is crucial in understanding the potential toxicity of coal dust and developing mitigation technologies.

Oct 12, 2022

By Lawrence S. O’Rourke

Pricing for tantalum raw materials experienced explosive increases in the period 1978-1979, and-similar declines over 1980-1982. The causes for this are examined. Negative effects on the industry are highlighted. Analysis is provided of subsequent structural changes within the industry which minimize probability of future pricing excursions. Data on markets, sources of material, and outlines of concentration and extractive processes are reviewed. The conclusion is reached that expanded sources, future flat demand, and a broader international base of industry participants are principal forces in this restructure. Flat demand is reviewed as a function of increasing application of tantalum, but in more cost effective forms. This is driven by technical advance, notably in electronics applications.

Jan 1, 1986

By C. E. More

Some observations on 'ancient' mining at Phalaborwa C. E. MORE. B.A. (Pretoria) (Visitor) A brief account is given of historical references to the Phalaborwa area, the first being to the mountain of copper and iron sought by Francois de Cuiper in 1725. These are followed by a description of several finds in the area, which are related to finds described in the literature and to Bantu tradition on the subject. Phalaborwa is one of the earliest known mining sites in the Republic of South Africa, Loolekop having been a mining centre, as shown by carbon-14 dating, since 770 A.D.

Jan 1, 1974

By Alexandre Alex) J. Bredikhin

"DISCLAIMER: the statements presented herein are those of the author and do not necessarily represent the views of US DoD or its Components.ABSTRACTProgress on the $750M lock project on the Monongahela River was derailed by discovery of large anomalies in the 6.5-7-ft dia. drilled shafts of the new river wall foundation. The anomalies were located 45 to 50’ below the top of the wall at the critical shaft-to-wall interface, and ranged in thickness from several inches to 2-plus feet. A Specialty team, comprised of representatives from the contractor, the Government, and structural design consultants, was formed to evaluate the extent of the problem and the impact on the new lock wall. With no standard method in place, the Government took the lead to develop acceptance criteria for the repairs while the contractor took the lead to identify the repair means and methods. The Government developed a detailed Quality Control plan to capture and document all of the repair data and to approve each shaft repair in a timely manner. This paper provides an overview of the anomalies encountered and the need for repairs; discusses the details of the repair plan; and provides details on the unique quality control measures employed to verify the repairs. By developing and adhering to a detailed quality control plan, the structural integrity of all of the shafts was successfully restored.INTRODUCTIONThe new Charleroi Locks Project is currently under construction by the U.S. Army Corps of Engineers (USACE) in Pittsburgh, Pennsylvania. In the region, the Corps of Engineers is modernizing the series of locks and dams on the Monongahela River. One facet of this modernization is replacement of the existing Locks #4 (aka Charleroi Locks) located upstream of Pittsburgh, Pennsylvania with new and larger capacity locks. The relative location of the project is shown on Fig. 1. The original construction of twin locks (56’x720’ & 56’x360’) and the fixed-crest dam was completed in 1932, with lock walls supported on timber pile foundations. The fixed crest dam was replaced with a gated dam in the 1960’s. The existing lock is undersized and in poor condition and thus needs to be replaced. The project requires the construction of the new river chamber adjacent to the existing land chamber which must remain operational to navigation throughout the construction. In order to accomplish this, the lock walls need to be constructed in the wet. The river wall was constructed using two construction methods referred to on the project as “cofferbox” and “non-cofferbox” construction."

Jan 1, 2017

Arthur Jarman, Sydney, New South Wales, Australia (communication to the Secretary*):—All designs for modern metallurgical and chemical laboratories should provide each student's desk with a hood or cupboard for the removal of fumes, but I doubt the advisability of placing air-baths and similar apparatus close to the hot plate. It seems to me that unless the draft be exceptionally strong the fumes from ordinary wet assay work will corrode the iron-work of the fittings, in which case the baths would have to be removed to a general desk in order to lighten the work of the laboratory attendant. Since the laboratory described by Mr. White has been in use for two years, I should like to ask if any inconvenience has resulted from this corrosion. If not, it is certainly an important improvement to have the air-baths and similar apparatus placed on the student's desk. The hoods described by Mr. White are supplied with a good draft by means of a fan, which gives them a great advantage

Jan 1, 1905

By Dennis W. Leonard

Let us begin our discussion by looking at historical and current levels of sales of both natural and synthetic zeolites on a world-wide basis. Due to the understandable reluctance of some companies to disclose sales data, some estimation has been necessary regarding the tonnages and values shown in Table 1. We are confident, however, that they are within acceptable limits, especially the numbers referring to natural zeolite.

Jan 1, 1979

By Stuart Coutts

"This paper presents an overview of the author’s experience related to the assessment of the base capacity of straight shafted and enlarged-base bored piles in sand. A design approach based on CPT qc is described which has been calibrated using a database of load tests. The importance of correct installation techniques with instrumentation are illustrated and a discussion is presented on the current use of high strain dynamic testing to validate compliance with design. An example of a recent project with high quality instrumented load test data illustrates the close match to the proposed best practice approach and also highlights the importance for consideration of the effects of stress relief for deep foundations installed in deep excavations.1 INTRODUCTIONContinuous Flight Auger (CFA) piles are the bored foundation pile of choice for sand deposits across Australia. The evolution of the determination of the base resistance of CFA piles has been shaped by available investigative techniques, calculation methods, and calibration of designs with laboratory and field testing. The Cone Penetration Test (CPT) has been widely used in Western Australia (WA) where the test has been commercially available via multiple contractors for more than 25 years. On the East coast, the adoption of CPT testing has been slower with a transition from traditional Standard Penetration Testing (SPT) still occurring. Dynamic pile load tests are often used to derive parameters. The influence of pile installation on performance is commonly misunderstood and is an important element on any discussion of pile capacity for CFA pile types. The interface between the base of the constructed pile and the in-situ soil has an influence on capacity such that a poorly constructed pile base will have limited (if any) contribution to pile performance within the normal working range, generally within a 10 mm movement. The research presented in this paper pertains to CFA piles (no drilling fluids) and enlarged base piles constructed using CFA techniques under drilling fluids such that clean pile/base interface is targeted. Developments in modern piling equipment and instrumentation allow the pressure and volume of delivered concrete/grout to piles to be accurately monitored at various stages of installation such that repeatable ‘best practice’ can be achieved. The changes in soil conditions that occur due to the disturbance of the install technique are also important.Although the results of this research are likely applicable to bored piles, the interface between the pile and in-situ soil (shaft and base) need to be considered for various installation techniques. The effects of stress relaxation (due to removal of soil above pile base and adjacent shaft), time to concreting, and the zone of disturbed soil around the pile shaft are paramount.2 INSTALLATION CONSIDERATIONS The pile mix (concrete/grout) and interface with the in-situ soil are also an important consideration. For example, coarse grained, poorly graded, dry, clean sand will be partially permeated by most pile mixes; such that the influenced soil will be enhanced and in instances the overall effective pile dimensions increased. Permeation of the disturbed zone of a pile or anchor shaft along with scale effects (Lehane 2009) can have significant effect on shaft capacity and shaft frictions significantly exceeding expected are not uncommon based on ‘theoretical’ dimensions. Advancements in mix technology and mix techniques also have a large influence on the pile/soil interface. The ability of the piling rig and augers to excavate a plumb and gauge hole can also have a large influence on the zone of soil disturbed adjacent the constructed pile with a resulting influence on capacity."

Jan 1, 1900

By William Seymour, L. D. Schmidt

"FOREWORDAmong many problems created by World War II, the question of supplies and distribution of raw materials is of outstanding importance. One of the most critical of these raw materials is fuel, and of the fuels coal is of primary importance. The normal consumption of coal has increased greatly owing to the increased tempo of industry in general. It has been necessary to divert much of the fuel oil, gasoline, etc., ordinarily used for industrial and domestic purposes, to supply the enormous demands of mechanized warfare. Coal must be provided to replace this fuel. Furthermore, the enormous increase in the production of steel has increased the demand for coking coals to a critical point.The Solid Fuels Administration for War is encouraging the use of anthracite fines in the production of byproduct coke for blast furnaces for three reasons. First, the production of anthracite for domestic use; is hampered by the inability to find a market for the fines incidental to the production of domestic sizes. Second, the shortage of low-volatile coking coal is acute, and any action that will decrease the quantity of low-volatile coal required will relieve the situation. As will be seen in this report, there is some promise that use of anthracite fines in coke-oven mixes will lower the amounts of low-volatile coal required. Third, utilization of those anthracite fines will tend also to alleviate the general fuel shortage. It has been the privilege of the Bureau of Mines to cooperate with the Solid Fuels Administration in the technical problems involved."

Apr 1, 1945

By Peter Grawenhof

In steel mills universal joint shafts, slipper spindles and gear spindles are used to overcome the design- and process- related offset between the axis of the motors and the work rolls. At the roll side the available space for the couplings is limited by the minimum work roll diameter. This leads to extremely high loaded components of the universal couplings especially at the roll side joints. Furthermore modern steel mills continuously strive to roll larger plates and materials with increased strength. This requires drive solutions with even higher torque capacity. For these applications conventional design joints are not sufficient anymore. Even alternative solutions such as hybrid- or offset- designs fall short. Therefore the companies Voith and BUMA Engineering developed together the new GearLink drive concept in close cooperation with the Voestalpine Grobblech GmbH. A completely new combination of universal joints and gear couplings offers an up to now unique solution enabling the use of 1,35- times bigger joint with a 2,5- times higher torque capacity and a 20- times longer lifetime. The GearLink system was first time successfully taken into operation at Voestalpine Grobblech in December 2013 and is up to now working without issue.

Aug 16, 2017

By James C. Duchon

The use of extended workdays (regular shift lengths of 10 or 12 h (hour), while still maintaining a 4O-h workweek) in mining operations is attracting growing interest in the United States. There is very little doubt that extended workdays is a very popular alternative among the work force because of the significant increase in days off, including weekends, especially when compared with traditional rotation schedules of working seven straight shifts or having only one weekend off every 4 to 6 weeks. However, there are some serious concerns by management, workers, unions, and various governmental policymakers that working 10-or 12-h days may create an added risk of accidents and health problems. The U.S. Bureau of Mines reviewed the literature studies related to the safety and performance issues of extended workdays. This report presents a summary of those findings. The studies examined in this review are divided into three sections: (1) laboratory, (2) field, and (3) accident and injury analysis. In general, results are inconclusive. Studies have shown both positive and negative effects. It is concluded, therefore, that in industries such as mining where accidents are a serious concern, special measures and evaluation in the use of extended workdays be considered.

Jan 1, 1994

By M Gasparon, J Harris, T Baumgartl, D J. Williams, M Edraki, P A. Kirsch, D Rowe

RISKGATE, an Australian Coal Association Research Program-funded (ACARP) initiative, has been designed to assist the Australian coal mining industry in improving minimum standards for safety performance, efficiency, operating practice and training. The online system is innovative in that it is built upon a foundation of industry expert knowledge gathered through action research workshops, which is further supported by a broad array of industry, academic and technical resources. In operation, RISKGATE offers a continuum for knowledge transfer and communication of current practice in risk identification, assessment and management in the coal mining industry. The primary mission of RISKGATE is to focus industry attention on prioritising control management as a way to achieve acceptable risk.A Coal Mine Tailings Dam Module has recently been added to the RISKGATE suite. The key risk, or initiating event, associated with coalmine tailings dams is catastrophic failure of the dam, leading to the release of tailings and water. This can occur due to geotechnical instability of the dam itself or of its foundation, overtopping and erosion of the dam, and piping failure of the dam itself or of its foundation. Coalmine tailings dams are also prone to seepage into the foundation and through the dam, particularly during operation when large volumes of water are discharged with the tailings. The most significant risk associated with seepage is the release of potentially contaminated water to the environment. Contamination can take the form of elevated salinity, acidity and dissolved metals. Run-off from coalmine tailings can cause erosion and can also potentially contain contaminants. Desiccation of the tailings surface can result in dust generation and dispersion.The paper presents the background and context of the RISKGATE project, the need for the addition of the RISKGATE Coal Mine Tailings Dam Module, and a description of the developed module, including the five initiating events considered, their causes and associated preventive controls, and their consequences and associated mitigating controls. This paper concludes with a discussion of the ways in which Australia’s coal mining companies are starting to apply the RISKGATE body of knowledge at their sites, which will flow onto the management of their tailings dams.CITATION:Williams, D J, Kirsch, P A, Gasparon, M, Baumgartl, T, Edraki, M, Rowe, D and Harris, J, ?2014. Application of RISKGATE to coal mine tailings dams, in Proceedings Life-of-Mine 2014 , pp 219–230 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Margaret Anne Stephenson

Today, in Australia, it is increasingly common to see agreements between Indigenous peoples and resource companies being achieved generally as Indigenous Land Use Agreements or agreements pursuant to the ?right to negotiation? process under the Native Title Act 1993 (Cth). Despite progress in this area, resource development on Indigenous lands is not without its challenges for both the resource proponents and the Indigenous parties. History demonstrates that resource development on Indigenous lands has produced struggles between the traditional owners of the land and the resource proponents. In Australia their relationship is generally defined by issues of access to land and assuring continued access to the land for the life of the project. In this context, divisions in Indigenous communities often emerge. The proposed resource project can have the effect of polarising members of an Indigenous community. It may be regarded by some traditional land owners as an advantageous opportunity for the community and by others as a hazard to country and culture. The process of agreement making has proved not only a test for the Indigenous community but also for the resource proponent. In this paper we undertake a contemporary case study of a proposed Australian resource related-development project on Indigenous lands. This project involved a multi-billion gas hub precinct proposed at James Price Point in the Kimberley region in Western Australia. The James Price Point proposal produced a litany of challenges for all parties. The traditional owners faced fundamental social and human rights issues, including a minority opposition to the project, the project's potential cultural heritage impact, the threat of compulsory acquisition of their native title interest by a State government due to an initial failure to settle an agreement, a fracture of their unsettled land claim and a minority rejection of the agreement ultimately reached. Additionally, the ?green? lobby also rejected the proposed gas hub on environmental grounds bringing the green lobby into direct conflict with both the traditional owners in favour of the project and the resource proponent. Ultimately, Woodside announced its decision not to proceed with the proposed gas precinct at James Price Point, in April 2013. In this paper we analyse the complexity of the James Price Point gas hub negotiations with the traditional owners which resulted in an Agreement that promised to deliver substantial benefits for the Indigenous communities. We question why such a favourable and beneficial agreement for the Indigenous community also produced the plethora of challenges and concerns and we consider how future negotiation processes could be better structured to avoid the difficulties that have confronted Indigenous land owners and resource proponents alike.

Aug 1, 2013

By S A. M Crawshaw, J A. B Fortune

Trackless battery powered haulage vehicles have been in operation in British coal mines principally for longwall face transfer and personnel transportation. Changes within the industry have resulted in the introduction of room and pillar coal mining methods and the introduction of increasingly heavier longwall roof supports This has resulted in the introduction of: • Battery powered coal haulage machines, which, without the need for trailing cables, increase productivity within room and pillar mining. • Battery powered longwall shield haulers which are capable of carry ing the heaviest shield supports currently being utilised within the British coal mining industry. The conventional machines have been adapted from an American design to meet the requirem ents of European legalisation. This has seen the- emphasis being placed upon the supplier with the European M achinery Directive being introduced, necessitating the assigning of a 'C E ' m ark to each vehicle. Battery vehicle technology has advanced to meet the demands of the ever changing market and will no doubt he further adapted to meet the requirement of the British coal mining industry.

Jan 10, 1996

By D. K. Crampton

ON giving thought to the subject of this paper, my first reaction was that many and striking changes have come about as a direct result of the war. However, more careful analysis indicates that few, if any, of these changes can be wholly attributed to it. The actual situation is that all these changes were conceived and most of them at least partially executed in re- cent prewar years, it remaining the role of war to achieve results in a fraction of the time that might normally have been taken, lacking its driving impulse. The further discussion will therefore be with the premise that the individual changes have been greatly hastened rather than directly and primarily caused by any war conditions. Co-operation among copper alloy producers on production problems is agreed to be much worth while. The industry was too long noted for jealousy and secrecy as to equipment, methods, and even materials produced. Gradually, a more open and co-operative policy evolved but even just prior to the war the interchange of ideas was relatively cautious and limited. The need for a great increase in production in record time fostered a more co- operative attitude; exchange of ideas and experience concerning all phases of production increased tremendously to the benefit of the individual participants and thus the war effort, too. This more united effort has undoubtedly led to many specific improvements in process or equipment and these in turn to more rapid and economical operation than could have taken place on an each-for-himself basis.

Jan 1, 1944

By Thomas E. Marshall, Patrick A. Kinek, Gerald L. Finfinger

The purpose of this investigation was to evaluate the integrity of the existing shutoff valves and actuators used under high-temperature conditions in the Bureau of Mines' horizontal borehole methane drainage pipe- line system and to determine the potential for improvement in the system. In the field tests, both fire-safe ball valves and standard brass ball valves were initially subjected to a 30-min pan fire without thermal protection. Neither valve could maintain line pressure beyond 11 min in a fire that reached temperatures between 500° and 700° C. Based on the test results, it was concluded that the brass ball valve used in the Bureau's methane drainage pipeline system can be retrofitted with an inexpensive "fire bag" to substantially increase its integrity under mine fire conditions.

Jan 1, 1986

By D. J. Bowen

"Abstract -The Great Dyke extends for 540 km along strike, to unknown depth, and varies in width from 3 km to 11 km. Rb/Sr age determinations gives values of approximately 2470 Ma.The Dyke consists of a variety of mafic and ultramafic rocks, many altered to serpentinites. These include, from top to bottom, successions of gabbro/norites, pyroxenites, peridotites/harzburgites, and dunites/picrites.The layers dip in from either margin, steepest at the edges (20°) and flattening toward the central sections. Four separate complexes are present. From north to south these are termed the Musengezi, Hartley, Selukwe and Wedza Complexes, and are described as 'boat-shaped' or 'pig-troughed'. All are similar in petrological sequences. Physiographically, the Dyke is spectacular in the north, where as a mountain range it meets the Zambezi Escarpment. Elsewhere in the central parts there is little surface expression and wide open treeless vleis. Dyke rocks cut through granite and schist belt terrain and are termed 'The Magnesia Belt'.Vast mineral resources exist. These include chrome, asbestos, platinoids, nickel, copper and gold. Up to eleven chrome seams numbered from top to bottom occur in the lower ultramafic sequences. Seams are narrow at 10 cm to 30 cm but of high grade. The platinum occurs 10 m to 40 m below the norite/pyroxenite contact.A 60 m wide zone of Light Sulfide Mineralization (LSM) of Jess than 1% sulfides extends from the lower gabbronorites into the upper pyroxenites. In this LSM, four enriched zones carry up to 5% sulfides. The most widespread is termed the Main Sulfide Zone (MSZ), below which is No. 2, No. 3 and No. 4 Sulfide Zones. The MSZ carrying pyrite, pyrrhotite and chalcopyrite is a multi­ element ore with components of PGE (Pt-Pd-Rh), nickel, copper and cobalt, and gold and silver.Extensive exploration programs have been carried out and the intention is to begin large-scale mining. However, with Russia supplying metals to the western markets, South Africa's cutback on production, and an end to the Cold War, delays have arisen."

Jan 1, 1994