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By P. W. Harben

Jan 1, 1985

By G. R. Heffernan

"In the early 1970ssteelmakers worldwide were looking forward to many years of expansion and profitability. Huge government investments in Europe, the United Kingdom, Japan, Brazil, and Venezuela were committed in anticipation of growing market s based on long-term OECD forecasts. In 1973 the first OPEC oil shock occurred. Steel demand shrank. Restructuring became the buzz word of the day as billions of dollars in taxpayers' money was poured into eliminating excess capacity and labour. In the United States, where government help was not available, inefficient companies went bankrupt; capacity was cut to 100 million tons from 155 million tons. The industry throughout the industrialized world shrank. By 1979the world economy seemed back on track and a modest degree of optimism could be detected in the international steel fraternity. Then came the second oil shock. By 1982 the industry was in the midst of another shakeout. More bankruptcies, more rationalization, and fewer jobs resulted. In Canada some well-known companies came close to the brink as low prices and high interest rates took their toll. In the light of the turmoil in the steel market over the past 20 years an attempt to forecast the trends through to 2001 is intimidating.However, there are good reasons to be optimistic today about both markets and technology.An economic super power is emerging in western Europe as 1992 draws near. The creation of a single market of 320 million well educated and economically ambitious people has major positive implications for steel demand. The mega projects of the channel tunnel, a European network of high speed railways, and the London docklands are the forerunners of greater things. Still to come is another $200 to $300 billion by the year 2001 in identifiable major projects for highways, railways, airports, water and sewage systems. Add to that the demands of an increasingly affluent population for automobiles, appliances and housing. On top of all that place large increasing demands for electric power and you have a potential beyond anything seen during the 1970s and 1980s. In 1988 the EEC steel industry operated at 90% and in 1989 at 92% of effective capacity. A surge in spot prices indicated that 92% was close to the ceiling. This pace moderated in early 1990 but any slack will probably be taken up rather quickly."

Jan 1, 1990

By John C. Edwards

Several experimental programs were conducted at the Pittsburgh Research Center to investigate the level of mine fire detection and alarm capability possible using state-of-the-art technology. These programs involved comparison of the response and alarm time of optical and ionization type smoke sensors to smoldering and flaming coal combustion in a smoke chamber. Coal combustion experiments conducted in the smoke chamber demonstrated that a CO concentration of 5 ppm above ambient corresponded to an optical density of 0.022m1. For the four smoke sensors for which a continuous analog signal was available, a smoke sensor alarm was defined as the average background signal plus ten times the peak-to-peak noise. This alarm criterion resulted in the association of the alarm for three of the four sensors with a smoke optical density of 0.022m-1. and 0.033m-1 for the fourth smoke sensor. The smoke sensors used in the smoke chamber studies were incorporated into large scale diesel fuel fire experiments conducted under normal ventilation conditions in the Safety Research Coal Mine (SRCM) at the Pittsburgh Research Center. These experiments showed that a diffusion mode smoke sensor alarmed earlier than a diffusion mode CO sensor; and, based upon the measurement of the optical transmission at the location of a pump mode ionization type smoke sensor that a pump mode ionization smoke sensor alarmed at an average smoke optical density of 0.021m" for the twelve experiments conducted. A series of 30 and 330 kW diesel fuel fire intensity experiments were conducted under zero airflow conditions in the SRCM. It was determined that :(I) thermal sensors are inadequate at 30 m from a 300 kW fire;(2) a diffusion mode ionization smoke sensor can be more effective for mine fire detection than a diffusion mode CO sensor;(3) recommendations can be made for sensor spacing in a mine entry based upon the measured CO buoyancy induced spread rates along the mine roof and the time for a developing coal fire to ignite a conveyor belt.

By M. Onifade, B. Genc, P. O. Akinseye, M. Fourie, K. O. Said

Coal is mined by both surface and underground methods and its extraction is normally characterized by numerous hazards that can lead to catastrophic accidents, which result in devastating effects such as injuries or fatalities, damage to mining assets, and destruction of mineral resources. These hazards exist due to the ability of coal to support combustion and its association with toxic, flammable, and explosive gases. Underground coal mining entails higher safety risks than opencast coal mining, chiefly because of issues relating to mine ventilation and mine collapse. Furthermore, coal mine collapses mostly occur due to crumbling of mining supports, especially in room and pillar mining systems. To avoid such adverse occurrences, safety management systems need to be in place. This study reviews the various technological safety systems and principles that are used for safe-rescue and self-escape of miners in underground coal fires, particularly in South Africa, using data obtained from Mines Rescue Services in Carltonville, South Africa. The outcome of the review shows that practising safety culture has been given priority across many South African underground coal mines through setting up safety management systems and encouraging workers to stay committed to safety principles.

May 2, 2022

The various risk components to be addressed by explorers and project developers (and their investors) to minimise and/or manage the risk of Pacrim mineral investment are summarised to provide an overview of the issues involved and to set the scene. It then highlights the role of individual Mineral Industry Professionals (especially independent consultants) who are at the heart of any risk reduction or risk management strategy. The involvement of accredited qualified/experienced (competent) and reputable professionals is essential to produce realistic and reliable results that gain and maintain investor confidence. Today, high ethical standards as well as technical competence are sought by government legislation/licensing regimes and initiatives of professional bodies like AusIMM, MICA, Professions Australia, Council of Professions, etc. All attempt to regulate and guarantee reputable individual professional behaviour (particularly in the context of currently perceived high corruption levels in many Pacrim countries). Brief comment will discuss the usefulness of accreditation and ethics codes plus other specific codes (eg JORC/VALMIN and their international analogues in Canada, South Africa, etc) in reducing risks.

Jan 1, 2004

By I. V. Samarasekera, E. B. Hawbolt

A review of recent work being conducted at the university of British Columbia on the modeling of the microstructural evolution during the hot rolling of steel is presented. A mathematical model of heat transfer was developed to describe the thermal field in a slab during rough and finish rolling. The model for rough rolling, discussed in this review, also simulates the growth of oxide scale on the slab surface. To quantify the heat transferred from the slab to the work rolls, instrumented samples of MSI3O4 L stainless steel, 0,05 per cent carbon steel, and 0,05 per cent carbon steel with 0,025 per cent

Jan 1, 1995

By J. Markgraaff

Because composites offer new solutions to materials problems, they are currently the focus of intense research and development worldwide. However, the natural tendency of users is to remain with tried materials in every situation of material selection. This approach ignores the tremendous advances that have been made in composite materials and their application. These advances enable engineers to tailor composites to suit specific applications such as the demanding needs of mining and industry in South Africa. However, the application of composites, where new and improved components and products are needed or are being developed is often hampered by the limited knowledge and experience of the engineers concerned. This paper presents some of the basic information needed for an appreciation of the terminology, definitions, and properties of various types of composites. It also reviews recent developments in manufacturing technology and product development that may find application in local industries and mining.

Jan 1, 1996

By Ben E. Lusk

During the past five years, the surface mining industry in Appalachia has launched itself into a technological revolution, which has never been equaled during a similar period of time. Operators have begun to realize that effectively restoring land to a useful purpose, to the satisfaction of all concerned, has to start at the beginning of the operation and be an integrated part of it throughout. In order to insure continued mining in the mountainous areas, with protection of aesthetic beauty, things really have had to change. And so the new steep slope mining theory of "controlled placement" has been developed. Controlled placement is a broad term which means the placement of spoil in steep areas where its condition can be completely stabilized and revegetated. This includes the head of valley fill, mountain top removal, haulback, over the shoulder, block cut, and any other methods where the over-burden is technically delivered, hauled, or compacted, so that there is no adverse after effects when mining has been completed. [(Fig. 1)] Under controlled placement, our whole approach to mining has changed. Before any displacement of soil or uncovering of the coal seam transpires, a complete drainage system

Jan 1, 1977

By William Connell

NFPA 502, Standard for Road Tunnels, Bridges and Other Limited Access Highways establishes minimum fire protection and fire life safety requirements for road tunnels, bridges and other roadways where access by emergency responders is physically limited. The 2008 edition of NFPA 502 represents the Technical Committee?s consensus of current best practice for fire protection and life safety requirements for road tunnels, bridges and similarly limited access highways. Research of national and international test programs, design guidelines and regulating standards was per-formed and considered in an effort to establish a singular, comprehensive document representing a recognized base threshold of fire safety in these type facilities. This paper provides an overview of the more significant revisions including the application of fixed fire suppression systems, guidance on tenable environment, protection of structure and dangerous goods transport.

Jan 1, 2008

By D. S. Yantek, R. J. Matetic, A. K. Smith, E. D. Thimons, J. Srednicki

In a 2007 report to the U.S. Congress, the Office of Mine Safety and Health Research of the U.S. National Institute for Occupational Safety and Health (NIOSH OMSHR) stated that built-in-place refuge alternatives (BIP RAs) provide significant advantages over mobile refuge alternatives. At present, the requirement to locate refuge alternatives within 305 m (1,000 ft) of working faces makes BIP RAs impractical in most coal mines. BIP RAs would be practical if three issues are addressed: (1) allowing BIP RAs to be located at greater distances from the working face, (2) developing a reliable process for the design and approval of BIP RA stoppings that meet the 0.1-MPa (15-psi) design criteria, and (3) developing systems that reliably deliver breathable air to the refuge alternative. In 2015, NIOSH OMSHR conducted a study of these three issues and issued a report. In the report, justification was provided for allowing the placement of BIP RAs at greater distances from the working face than the currently mandated 305 m (1,000 ft), guidelines were developed that could be used by industry when submitting BIP RA stopping design applications for approval which are patterned after the Mine Safety and Health Administration guidelines for coal mine seal design applications, and insights were provided into options for providing a reliable supply of clean, breathable air to BIP RAs. This paper presents a summary of the study’s findings and also addresses issues discovered during the building and designing of a BIP RA that OMSHR researchers constructed in NIOSH’s Experimental Coal Mine in Pittsburgh to research the testing and improving of BIP RAs. These issues include several issues related to the delivery, distribution and exhaust of ventilation air to the BIP RA and some general construction issues that require further investigation.

Jan 1, 2016

By Osamu Iida

Since 'start-up of the larger Mitsubishi Continuous Copper Smelting Process in 1991, furnace relining campaign was gradually prolonged to once every 2 years according to deregulation of governmental boiler inspection. On the other hand, in 1998 Naoshima smelter embarked on an intermediate strategic expansion plan to strengthell its international competitiveness. As part of this plan, modifications were implemented in the copper smelter designed to increase output of anodes from new charge source to 270,000 tpa. In May 1998, treatment of dried neutralized residue was started in C furnace, and during the shutdown for brick relining in April 1999, intensive modifications to the boilers as well as the installation of new spray coolers for furnace off gas treatment were implemented. Finally, the new larger oxygen plant was commenced its operation in May 2000 and the expansion was achieved around 30% increase of anode production from original design.

Jan 1, 2001

By Joe Price

Canada?s energy future will increasingly depend on a supply of light, sweet crude oil derived from the Athabasca oil sands deposit of North-eastern Alberta. Billions of dollars are being spent on the construction of new and expanded mine and bitumen extraction plants, in situ recovery facilities, pipelines, upgrading installations and all the infrastructure needed to support these projects. The success of the existing operators has also inspired new players, anxious for ?a piece of the action? to come forward with exciting project proposals of their own. None of this investment and spin-off economic activity would be taking place today if events had unfolded differently in this part of the world some one hundred million years ago. The accumulation of sand in rivers, estuaries and in the near-shore marine environment created the great reservoirs that host the enormous oil deposits these projects are designed to exploit. Mine operators of all stripes will likely agree that there are few good ?geological surprises?. With specific reference to oil sand deposits, the geological history determines the distribution of sand, silt and clay bodies, which in turn controls the ore grade. Important design factors including everything from stable pit slope angles to tailings properties reflects events that took place millions of years before. An understanding of the sequence of events that resulted in deposition and preservation of the sediment and oil are important to sound design for both mining and in situ facilities. A geological history of the region is described. Site-specific examples from Syncrude?s operating mines are used to illustrate some of the geological factors that can present design challenges.

May 1, 2003

Over the past 12 years screening of materials has undergone a dramatic change in both the types and materials used in screen mats and the quality requirements of the finished product. With the main thrust now on quality and a cleaner product a different approach was needed in the operation of sizing screens. New screen mats with many different aperture configurations have been developed using rubber and plastics.to replace the traditional screen mat of woven wire or punched plate.

Jan 1, 1984

By Y. P. Malhotra, JE. C. Carter

"Syncrude's overburden removal requirement ranges from 20 million to 30 million bank cubic metres per year to meet tarsand demands for the production of 129,000 barrels of synthetic crude oil per day. The economic tar-sand lies beneath a variable thickness of overburden materials, composed of silts, clays, some sands of lacustrine origin, wind-deposited sand dunes, and out-wash sands and gravels.For the removal of overburden, Syncrude commissioned its own mobile equipment fleet in January 1981. This fleet consists of two Demag 241 hydraulic shovels, ten Titan 33-15B trucks and support equipment. Prior to this, all overburden removal was being carried out by contractors.This paper presents an overview of overburden removal at Syncrude, with particular reference to the performance of its own fleet.IntroductionThe Syncrude Tar Sands Plant was officially opened on September 15, 1978. After an expenditure of approximately $2.26 billion, the second and the largest commercial tarsands plant was on stream toward a permit production rate of 129,400 barrels of synthetic crude oil per day. The Syncrude Plant, a joint venture of six oil companies, the federal government and the Alberta government, is a major step forward toward the goal of Canadian energy self-sufficiency.The Mildred Lake operation of Syncrude Canada Ltd. Is located 40 km north of Fort McMurray and 480 km northeast of Edmonton in the Province o f Alberta.Synthetic crude oil leaving the plant is a blend of two-third s gas oil and one-third naphtha. The two streams combine in a pipeline and flow to Edmonton. The product takes six days to make the journey, arriving at four locations in the city Imperial's Strathcona Refinery, Gulf's Edmonton Refinery, the Interprovincial pipeline terminal and the Trans-Mountain pipeline terminal. Each Syncrude owner receives a share of oil equal; to its percentage of ownership in the project. At the present time, the oil is being utilized by Canadian refineries from Vancouver to Montreal."

Jan 1, 1983

By Harry E. LeGrand

Most mine operations are hampered to varying degrees by excessive inflow of water into mines or scarcity of water for processing the materials. These internal problems are compounded in many cases by such external hydrological problems as lowering of ground-water levels in areas outside the mine properties, subsidence of ground surface, adverse geochemical changes, and pollution. The development of a mine below the water table disturbs the natural ground-water system, causing a convergence in the flow of water from a surrounding area. The mine becomes the apex of a depressed cone in the water table. The fact that mines are commonly located in complex and somewhat anomalous geologic environments prevents an idealized treatment of the mine as a well that would be similar to a water well in a homogeneous aquifer having isotropic conditions. Yet, adherence to some principles of ground-water behavior is helpful when combined with an understanding of the local geology. A program calling for an appraisal of all pertinent hydrological conditions prior to mining and during various stages of development should supply adequate information for mine officials to anticipate difficulties and to allow for corrective measures. Before and during mining operations there should be a mine hydrology framework and plan, in which there is continual upgrading of such considerations as anticipated actions, consequences of actions, remedial plans, and contingencies.

Jan 1, 1973

By J. M. Mutmansky, R. A. Jankowski, M. A. K. Mohamed

"SYNOPSISKnown health hazards associated with the breathing of respirable dusts, particularly silica dust, during mining are becoming a great concern in many parts of the world. The search for effective and low cost dust control methods for underdeveloped countries will help in improving the productivity and keeping the mine environment safe. This article addresses the problem by providing suggestions concerning the easiest and most cost effective methods to control respirable dust in mining and mineral processing operations. INTRODUCTIONMedical BackgroundLung diseases caused by dust in mining operations have been recognized by mankind since the time of the Roman Empire. The writings of Pliny the Younger on natural history reported on maladies associated with dust in mining in the first century AD. However, no significant advances in controlling the lung diseases of miners came about for many centuries. The effects of mineral dusts were further described by Georgius Agricola in his sixteenth century book on mining (Agricola, 1556). After the appearance of Agricola""s book, lung diseases were more readily recognized, but the nature and severity of the ailments associated with mineral dusts could not be readily interpreted.In 1896, the discovery of x-rays by Roentgen advanced the diagnosis of lung diseases and the knowledge of what causes these diseases. In addition, the discovery allowed medical personnel some method of judging the extent and severity of the lung diseases in human beings. During the ensuing years, the term 'pneumoconiosis' became the common term to describe any of the diseases of the lung in which dust particles deposited in the lungs caused fibrous tissue and loss of some of the respiratory function. However, little in the way of social remedies for the diseases resulted until much later. Society was still not ready to act decisively to reduce the causes of lung disease due to the dusty conditions in the work place.Social action against lung diseases did not occur in the United States (US) until the 1930s. At that time, a tunnel driven through a sandstone mountain near Gauley Bridge. West Virginia, caused the death of several hundred workers due to acute silicosis, a severe form of pneumoconiosis caused by silica (Seaton, 1975). Dust conditions in this tunnel were quite bad, causing many of the workers to be subjected to extremely high silica dust concentrations. The severity of the disease in many of the workers became known to the public and prompted the US Congress and many of the states to enact laws to reduce the dust levels."

Jan 1, 1998

By Marcela Morvová, Mário Janda, Morva Imrich

"The possibilities of greenhouse gas mitigation using various methods are brought out. The special case of utilization of mixture of CO2 with other greenhouse gases in a synergetic way inside non-thermal plasma based system is described in detail.Measurements on pilot system comprising pyrolysis chamber as alternative energy system (production of hydrogen and liquid tar) were made for various biomass and waste as the input material. The exhaust from this system was treated with non-thermal plasma gap suitable for up to 650Nm3/hour of exhaust gas flow. Condensable portion of exhaust is liquefied in distillation unit; produced hydrogen is stored on-line inside nano sized carbon of our own production.The CO2 removal efficiency varies depending on exhaust composition between 45 to 98%. Other oxides as CO, NOx, SOx and several hydrocarbons and VOC are also removed. The main product connected with CO2 removal is a solid powder of proteinoid nature. There exist strong probability, that precursor of the origin of life on the Earth from primary atmosphere were formed in the similar way as it is present in the electric discharge system used. Our system is equipped with on-line as well as ex-post analysis of all forms of products. We have also developed a system for recuperation of all forms of produced heat. It is stored inside as latent heat of waxes.IntroductionNatural greenhouse effect on the Earth is caused mainly by water vapour with the average absolute concentration about 4%. Other gases able to absorb long-wave radiation and thus this causing greenhouse effect are CO2, CH4, N2O, halocarbons and as precursors ozone and NOX. Some of them we produce and introduce into atmosphere in large quantities during production of energy and in transport. This factor leads to permanent increase of average temperature of air, sea and oceans, so called global warming.Nowadays large amount of data exists showing that the temperature of Earth in the last 150 years has been continually increasing. It represents about 03°C per ten years and the most of climatologist believe, that the increased concentration of greenhouse gases in the atmosphere is responsible for this effect.The most important greenhouse gas is carbon dioxide CO2. Majority of CO2 emissions comes from electric power stations working with fossil fuels, cars and industry. Burning of fossil fuels contribute up to 80% to world wide anthropogenetic emissions of CO2."

Jan 1, 2010

By George Gardner

The rapid growth of highwall mining in the Appalachian coalfields has resulted in unique safety concerns. Due to the concentration of activity at the base of the highwall and the potentially destabilizing influence of the mining process, proper mine planning and continual monitoring of the ground conditions is essential to ensure a safe and productive operation. This will also help to minimize the need to recover equipment that has become entrapped underground, and the subsequent hazards associated with a recovery operation. Adequate geotechnical site investigation and rational design methods should enable mine planners to properly account for the site-specific conditions that influence web and abutment pillar, roof, floor, and highwall stability. This paper examines the growth of highwall mining, provides a general overview of the various safety concerns, and reviews the modes of highwall failure as they relate to a highwall mining operation. Gcotechnical considerations that should be taken into account before and throughout the mining operation are emphasized. The importance of closely examining and monitoring highwall conditions for subtle signs of highwall instability will be discussed.

Jan 1, 2002

By D Michaelsen, S Miller

The Grasberg Mine is a copper and gold open pit mine operated by PT Freeport Indonesia (PTFI) and located in the high equatorial mountains of the Indonesian province of Papua. The climate is alpine/subalpine with little seasonal variation in temperature or rainfall. The daily average temperature ranges from about 2¦C to 14¦C and the annual rainfall in the vicinity of the mine and overburden stockpiles is about 4000 mm to 5000 mm. Mining of the Grasberg open pit will continue until 2014 at which time approximately 2750 Mt of overburden will have been produced. Current overburden production rates are 200 Mt per annum. The current mill rate is 230 000 t/day from the Grasberg pit (190 000 t/day) and the underground operations (40 000 t/day). The acid rock drainage (ARD) issues associated with overburden from the Grasberg operations were identified early in the mining operation. Almost all overburden placed to date has been Potentially Acid Forming (PAF). Laboratory testing has identified four main overburden types: limestone and non-acid forming (Green waste), PAF low capacity (Blue waste) and PAF high capacity (Red waste), and Heavy Sulfide Zone (HSZ), which contains greater than 20 per cent pyrite. Waste type block modelling indicates that at least 30 per cent of the overburden production from 2003 to the end of Grasberg pit operations will be limestone. Strategies are being developed to maximise the beneficial use of limestone through strategic blending and placement for ARD mitigation and control.

Jan 1, 2003

By Dhanesh Chandra

In this symposium, research in the area of energy conversion is presented. This symposium has special significance, as we honor three prominent scientists from hydrogen storage research and development field. In this symposium, the majority of papers presented by international scientists and engineers are in the area of hydrogen storage. Other energy conversion papers include magnetic materials, superconductors, and thermal energy storage materials. Recent developments in light-weight high gravimetric hydrogen density hydrides have led to potential use of hydrides for onboard automobile and other applications. This, of course, is significant from environmental concerns of CO2 and other emissions from the current use of carbon based fuels in automobiles. Thus, it is becoming increasingly important to switch to cleaner alternative fuels such as hydrogen [1]. The Challenge of Vehicular Hydrogen Storage as potential hydrogen energy carriers for vehicular applications, with a driving range of approximately 300 miles, require ~5-13 kg of hydrogen stored on-board. In the United States, Centers of Excellence have been established in metal hydrides, chemical hydrides, and carbon-based materials, and abundant scientific and industrial research is being carried on metal hydrides; only some of the current research from the Centers will be reported here. The European commission, Japan Institutions, and others also have numerous hydrogen storage programs in progress. Several international collaborations have also begun between IEA and IPHE scientists to accelerate the progress of development of practical hydrides. A summary of the abstracts is included in this overview.

Jan 1, 2006