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By Michael Elliot-Jones

The fundamental competitive structure in world coal markets will be modified by the entry of such new participants as Colombia and the newer mines in South Africa. The US will, in most markets remain the swing producer, although a number of low cost US mines will continue to compete in world markets. Exchange rate swings will persist as a major hazard for coal exporters.

Jan 1, 1986

By J. L. Marchese

Belt conveyors face their applications life with a promise of constant abuse: heavy and rough products cascade onto the belting without let-up; caustic and abrasive materials such as salt and ore eat away at the cover; high temperatures, even open flame at times, sear and soften belting materials; and unyielding tension stretches and strains every belting component. The only defense against the applications onslaught is to follow the basic rules of proper handling, installation, and maintenance. Under the direction of qualified personnel (one responsible person, if possible), you can insure that conveyor belting begins operation in top condition.

Jan 6, 1980

By Gh. Crutu

This paper treats some aspects of the research completed on the impact of the waste generated in the production process of a chemical fertilizer, phosphogypsum, on crops and yields. The article starts with the basic data and the research methods, and continues with details about the research results on the heap waste of phosphogypsum and the soil from its vicinity along with the content in radioactive elements, humus, macro elements and mobile forms of heavy metals. Finally, the absorbtion of radioactive elements from the soil and the uranium concentration in the agricultural cultivations is presented.

Jan 1, 2006

By R. A. Lowe, P. B. Malla

Smectite is a common impurity in the kaolins of Georgia.This impurity is harmful to the low-shear rheology of kaolin slurries in concentrations as low as a few weight percent. The deleterious effect of smectite on the low-shear rheology is due to the swelling of the mineral. Montmorillonite containing clays were treated to precipitate a compact brucite layer {Mg(OH)2} in the interlayer region of the expandable layer silicate mineral. This treatment forms ahydroxy-Mg-montmorillonite with characteristics similar to chlorite. This treatment effectively reduces the swelling capacity of the mineral and improves the rheological properties of kaolin slurries contaminated with smectite impurities.

Jan 1, 1999

By R. J. McGregor, Deepak Malhotra

Engineers frequently encounter situations where decisions that are counterintuitive to the logically trained engineering mind are made because of other influences, whether they be financial, social, cultural, or environmental. Such influences can overrule the "logical" decision-making process. The aim of this book is to explore some of the nontechnical issues, which most engineers don't learn about in school, that can have a major impact in the mining industry. This chapter gives a brief overview of this volume and introduces the topics that will be addressed.

Jan 1, 2001

By H. Schultheis

The European Commission has launched in April 2002 the Thematic Network NESMI with-in the FP5 under Growth. NESMI stands for ?Network on European Sustainable Mining and Processing Industries? and will run until 2005. Within NESMI there are different ways to set up indicators and evaluate them throughout the NESMI Members. First analyses concerning the Demand and Competence within NESMI are developed. New focus points for analyses can be implemented into NESMI.

Jan 1, 2003

By D. R. Taylor, R. G. Goss

The use of clay granules as carriers for pesticides dates from the early 1940's and by the present day represents a business conservatively estimated at between 200 - 300 thousand tons / year in the U.S. alone. Aside from economic and specific target pest efficacy advantages, the use of clay granules as pesticide carriers also delivers a number of environmental benefits which will be reviewed. Topics to be discussed will include: 1) drift control (versus liquid sprays), 2) mobility (in the environment), 3) worker safety, and 4) transportation (spill) safety.

Jan 1, 1999

By T. S. Golosinski

Timely and efficient conversion from traditional to sustainable development of mineral resources requires that managers, engineers and other mineral industry professionals become familiar with the related techniques and methods. To fill this need the online Master of Engineering program has been developed at University of Missouri-Rolla. Designed primarily for mature students with an engineering or science background this program allows for specialization in several areas of sustainable development of earth resources. To accommodate mineral industry professionals working in remote locations all courses constituting the program can be taken online, without the need to attend the classes in person. The paper describes the program and discusses the experience gained during the first two years of program offering.

Jan 1, 2003

By Alfred G. Hoyl

The small miner and small mine have an important role to play in the finding, developing and production of our mineral resources. "Help, not hinder" must be our byword. We must push in every way we can devise to change the adversary position of government and environmental movements. We need the small mines and they must be encouraged, not hindered. Technically excellent and adequate equipment is available, and needed information is also available to the small operation. Environmental questions and problems must be fully considered regardless of the size of a mining operation.

Jan 1, 1987

By K. N. Hebbar, R. G. Reddy

Spent potliners (SPL) were declared hazardous waste under RCRA (K088) in July, 1990. The glass formation characteristics of the SPL was studied. The SPL glassy matrix were analyzed using X-ray diffraction and optical microscopy. Results showed that SPL can be fixed in a glassy matrix with the addition of sand and limestone. The optimum amounts of additives were determined for obtaining the best glass formation characteristics.

Jan 1, 1995

By Tien H. Wu, Pinnaduwa H. S. W. Kulatilake

The concepts of conditional probabi1ity and geometrical probability are used to establish a relation between the probability density of the trace length and the probability density of the discontinuity diameter. The discontinuity is represented as a thin circular disc. A numerical solution scheme is used to obtain the probability density of the disc diameter from the probability density of the trace length. An example was used to illustrate the possibly large difference between the mean discontinuity diameter and the mean trace length.

Jan 1, 1986

By P. J. L. Nel

The paper describes several successful concepts used in the sinking of shafts on the Elandsrand Gold Mine. The concepts enabled the shaft sinking time to be reduced as well as the period in which development would normally take place to establish initial ore reserves.

Jan 1, 1981

By N. B. Greninger, M. J. Sapko

The US Bureau of Mines conducted, through joint funding with the Colorado Mining Association, large scale oil shale rubble fire tests to investigate flammability characteristics and different methods of extinguishment. Ignition of large rubble piles was easily accomplished. Foam blankets could be used to control surface flames. The results of these large scale tests confirmed that water was effective but not particularly efficient in extinguishing deep seated oil shale fires. It took up to 1.7 times as much water to extinguish afire as anticipated on the basis of a simple cooling model, assuming 100% utiliza-

Jan 1, 1991

By A. C. C. Pacheco, L. C. Bertolino, M. L. Torem

On account of geological characteristics, Brazil is a country of large deposits of high quality kaolin, with the larger ones being located in its northern region. In the last years, kaolin beneficiation and production area is receiving great investments, aiming at a high quality kaolin production to be used in the paper industry, mainly intended for the foreign market. After the conclusion of expan- sion programs and with the advent of new production areas, Brazil is very soon expected to come in second place in the kaolin world production ranking.

Jan 1, 1998

By R. Matikainen

Since the Brundtland Commission in 1987, the use of natural resources has been an issue of global concern. Minerals are among the most important Earth resources and will definitely be essential for the development of societies also in future. Increasing scientific effort is needed not only to discover new deposits, but also to promote resource management in ecologically and socially sound way. Sustainable resource management is essentially a multidisciplinary challenge of developing life-cycle analysis and recycling of non-renewable resources from local to global scale. It offers great opportunities for geological surveys not only in EU, but all over the world to contribute positively to the welfare and sustainability of societies.

Jan 1, 2003

By James G. Sack, Donald G. Wieland, James H. Meinholz

The paper will describe the $1.7 billion Milwaukee Program. Past contracting practices of the Milwaukee Metropolitan Sewerage District are discussed. To minimize costs and claims, the MMSD has implemented some recommendations from Better Contracting for Underground Construction. Currently implemented are: full disclosure of subsurface data including interpretations, the deletion of disclaimers relating to subsurface information, use of the federal Differing Site Condition clause, payment for mobilization. Also considered was the recommendation concerning Wrap Up Insurance. The MMSD shares and allocates certain designated risks through the Contract. A claims handling methodology has been developed and used on this major construction program.

Jan 1, 1983

By Shuyu Qin, Shujiang Sun, Jingfu Zhao

The three key parameters of mine fires are local airflow velocity, temperature and oxygen concentration. According to the theories of seepage in porous media, heat transfer and heat dispersion, mathematical models were constructed based on the three parameters. The models can be used for early prediction of mine fires and for estimation of the level of spontaneous combustion. Proper use of the models can assist in preventing and controlling mine fires. KEY WORDS: airflow velocity, temperature, oxygen concentration, numerical modelling, mine fire prediction.

Jan 1, 1993

By Joe Hudson

The successful heap leaching of tailings as illustrated in the two photographs below, requires special provision. These will be enumerated in the presentation. The two illustrations show the project as it evolved. Note the bermed pads and the conveyor materials handling system which provides for agglomeration of the feed material.

Jan 1, 1998

By K. D. Allen, M. J. Blattman

The problem of measuring the amount of rock removed during a given time interval is faced by most mining operations. Many methods have been developed with varying degrees of success, dependent upon the mining method and the availability of usable data. The Rosebud Mine has been in production for nearly two years, employing several techniques to estimate monthly production from underground production stopes. The use of three-dimensional solids generated from survey data has greatly improved the reliability and confidence of monthly production reports. The authors will summarize the methodology currently being utilized at Rosebud.

Jan 1, 1999

By Daniel P. Farjeat, Hector A. Canseco, Juan M. Schmitter

Since the early sixties, tunneling in the soft clay of Mexico City, has been done with the aid of open face shields and recently with compressed air. The use of pressurized shafts up to 1.5 kilograms per square centimeter, (147 kilo pascals) with vertical locks to launch the shields, have been used in two cases. After advancing almost 200 meters of tunnel, the same vertical locks were transformed into horizontal locks, to continue the work. Due to the high decompression times involved, it was necessary to install long locks, using the tunnel itself as part of the system. This article describes those cases.

Jan 1, 1981