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By F. F. Peng

An economic analysis for evaluating coal preparation in Appalachian Region is presented. A complete coal preparation plant is used to deter- mine the capital and operating costs. Using profit maximization as a decision criterion, an optimal process flowsheet for given coal characteristics can be selected among the process alternatives by a process-economic model. A deterministic analysis is used to calculate the discounted cash flow interest rate of return and project the selling prices of clean coal products. A probabilistic evaluation is further made to quantify the risk involved in obtaining the desired profit levels.

Jan 1, 1979

By Richard W. Kimball, Richard F. Coon

This paper describes drill and blast excavation and groundwater control measures at the Lake Mead Intake No. 2 project. The construction includes a deep access shaft, intake shaft, surge chamber, forebay chamber, intake tunnel, 22 well shafts and East Tunnel. Grouting ahead of the excavation face was used extensively during shaft and tunnel construction. Lake Mead Intake No. 1 was constructed in the early 1970’s under less severe groundwater conditions and this work was delayed by ground conditions and water control problems. Excavations for Lake Mead Intake No. 2 must be completed in 23 months to meet SNWA’s water delivery schedule.

Jan 1, 1999

By Chien-Tsun “C. T. ” Chu, Drupad B. Desai, Ron E. Redd

The 12,710-m (41,720-ft) Riverside Badlands Tunnel is located between the most active faults—San Andreas and San Jacinto—in Southern California. To accomplish the impervious final lining design and to accommodate the effects of earthquake ground motions, a new approach was developed and is prescribed in this paper. Two final lining options, welded steel pipe and prestressed concrete cylinder pipe, are considered for the tunnel, which will be excavated under groundwater and ground conditions from soft rock to hardrock at depths exceeding 244 m (800 ft). The buckling strength, serviceability, and structural integrity under seismic effects and other loads were considered in the design.

Jan 1, 1997

By R. K. McFarland, E. S. Diamant, L. Blake

A number of concepts for basing strategic missiles facilities deep underground have been developed within the defense industry. Recently, several contracts were let by the Air Force Ballistic Missile Organization to better develop system concepts for Deep Basing and Rapid Egress of Missiles from these facilities. A particular challenge of the Deep Basing Concept is the need for the excavation of egress tunnels or shaft from the deeply based facility to the ground surface, in a rapid and reliable manner. This Paper describes a conceptual MX-Deep Basing Facility, the technical issues associated with its design and construction, and potential means for achieving rapid egress from this facility. Manuscript not received in time for publication.

Jan 1, 1983

By Blagoj Golomeov, Boris Krstev

Nowadays, in the papers of authors in the area of flotation concentration, we can find several equations that describe the kinetics of flotation process as follows: Agar's equation, Klimpel's equation, Beloglazov's equation and Group of authors' equation (equation with two kinetic constants). This paper makes an attempt to determine the most appropriate equation for mathematical interpretation of kinetics of the SASA mine rougher Pb - Zn flotation.

Jan 1, 2002

By P. R. Bridenbaugh

The products of the coming decade will possess such stringent design criteria that it is unlikely today's monolithic materials will be able to meet them. The discovery, characterization and cost- effective manufacture of a whole new generation of highly engineered materials therefore have become essential requirements for participation in the materials marketplace of the 1990s and beyond. Meeting these challenges will require advances on a broad variety of scientific and engineering fronts, including: strengthened fundamental understanding of materials behavior; composite and laminate programs offering the compatible and synergistic combination of metals, ceramics and polymers; advanced engineering and structural design techniques; processing technologies capable of producing advanced materials efficiently; and, the development of new products taking advantage of the availability and cost-effectiveness of these highly engineered, advanced materials.

Jan 1, 1986

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 J. E. Warm

Florida’s ancient beach ridge sand deposits, mined for construction aggregate, are highly variable. Rinker Materials utilizes a small reverse-circulation drill rig to prospect and profile unconsolidated fine aggregate deposits more effectively and inexpensively than other drilling methods. Sample data is stored in a spreadsheet that calculates yield and volume. Rinker also uses a Trimble ProXR backpack GPS to locate boreholes in the field, track mine progression on a monthly basis, and to map restrictive features such as wetlands. Autodesk Land software is used to create detailed deposit maps and mine plans. Rinker believes that these practices have led to improved awareness of deposit characteristics and deposit utilization.

Jan 1, 2004

By V. R. Degner

Development of large mechanical flotation machines during the past fifteen years. This success was a contributing factor in recognizing the value in a systematic and rational means of optimizing the flotation circuit, where the preferred circuit arrangement is based on both economic and metallurgical performance considerations applied to a relatively small number of flotation machines. Flotation kinetics and effective pulp residence time models have been incorporated into a computer program, described in this paper, which has proven to be an effective analytical tool to quantitatively relate flotation process parameters, such as feed tonnage and grade, solids concentration, and reagent strategy, to flotation circuit arrangement, machine size and operating condition.

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 F. Wendling, G. M. Peixoto, J. A. M. Cano

A brief introduction is made on the existence of sulfides in the top gas of the Midrex Shaft Furnace, giving consideration to the operation of the furnace and the liberation of sulfur, as well as its consequential effects on the reduction process. The text shows a study of sulfur distribution in the pellet, emphasizing the importance of this distribution in relation to the liberation of sulfur during the reduction. A study was made to determine the sulfur compounds that exist in the pellets, showing ways of controlling the sulfur distribution and reducing its liberation during reduction.

Jan 1, 1991

By A. Geertsema

Introduction Gasification of coal has been practiced for many decades for the production of gas, fuels, chemicals and power. However it has only more recently started to get significant attention in the USA. In this review of the basics the features of gasification as compared with combustion is covered and the potential of increasing the conversion of coal via gasification is indicated. After dealing with the fundamentals of gasification a review of gasification technologies will be presented with an indication of the widespread international and more limited US use of this technology. In conclusion the attention will be directed at the future prospects of gasification.

Jan 1, 2006

By Isobel Clark

The four papers in this session illustrate two different directions in which computer graphics seem to be developing. The first of these is in the handling and storage of geological information. The increasing use of micro-computers with limited storage facilities has seen a concomitant increase in the need to store geological data in as efficient a form as possible. It has also seen a recognition of the particular types of data which are used in a geological or mining analysis. Unlike many other fields, observations of drill cores, geological interpretations, structure and many other variables require storage in a readily accessible form. The authors of two papers in this session deal directly with Geological Information Systems. They discuss the setup, the specification of such systems, and the practical uses of the systems once in operation.

Jan 1, 1989

By R. J. Miller

The current US national commitment to expanding the human presence into the solar system will clearly require major facilities in Earth orbit or possibly on the Moon. Such facilities will need large amounts of materials for structural modules, life support, propulsion and shielding. The heavy transportation costs in fuel required to lift materials from the Earth's surface make a terrestrial-based space system inherently inefficient. A more cost-effective approach would be to provide as much of the required materials as possible from other bodies in space not having the high cost of Earth launch. This paper identifies potential targets for space-based resource utilization, constraints on exploitation and relative benefits of various sources.

Jan 1, 1994

By S. N. Groudev

Intensive uranium mining activities at the Curilo deposit in Bulgaria has caused widespread contamination over a wide area. A number of receptors including soils and watercourses as well as the ecosystems in the area have been severely affected. Even today, 10 years after the cease of activities, acidic waters generated from the abandoned mining works, the low-grade ore and waste dumps contaminate soil, surface- and groundwater. The present paper describes in general the environmental status of the wider Curilo area and examines the potential of preventive and remedial measures that can be applied in situ to rehabilitate the site and restore the ecosystem. The main rehabilitation technologies examined include modification of the acid generation potential of the pollution sources, treatment of the acidic drainage by means of a natural wetland and in situ bioremediation the of contaminated soils. Finally, a number of efficient indicators are proposed so that the rehabilitation potential at Curilo and similar heavily contaminated sites is assessed.

Jan 1, 2003

By Robert C. Dunne

Nearly one third of Australia's total gold product is produced in the Kambaloa - Kalgoorlie - Leonora Goldfields. There are presently some 25 gold mines in the area with the possibility of another six plants being constructed in the next year. Details of the gold extraction techniques used on these mines will be discussed and certain innovative technologies and problem areas will be highlighted.

Jan 1, 1998

By John Turner, David Carey

The Robbins Mobile Miner demonstrates the successful combination of hard rock excavation technology and the latest electronic control technology. The mobile miner, a partial face hard rock tunneling machine, features a fully integrated control system relying on a Programmable Logic Controller (PLC). This PLC controls all functions: tramming, steering, boom swing, cutting depth, conveyor operation, air scrubbers, hopper loading and unloading, etc. The machine is fully instrumented allowing the PLC to monitor the results of all commands on a continuous basis, to record data, to evaluate developing problems, or to shut the machine down if necessary. The paper describes the development of the Robbins - Pasminco automated mobile miner and early testing at Pasminco Mining's Broken Hill Southern Operations, New South Wales, Australia.

Jan 1, 1993

By R. J. Wesely

It is obvious from recent events in The Peoples Republic of China that a major effort is underway to increase trade with the Western World. The production of Gold contributes to China's ability to participate in international trade and consequently they place a high priority on increasing gold production. Many of the operating gold mines in China contain refractory ores which to date have not been efficiently treated. Figure 1 illustrates the description and location of some of the major gold mines in China. Recognizing that the technology necessary for the economic treatment of this ore has been developed in the United States and other Western Countries, China has begun to seek assistance in evaluating several potential projects. This paper will examine the recent history and current trends in developing a refractory gold treatment project in China.

Jan 1, 1993

By R. Markovic

The objective of this research study was the investigation of heavy metal removal from wastewaters of the "SARAKA" stream by using low-cost materials. These wastewaters flow into Krivelj River and through the network of existing rivers into regional water reservoirs. Sawdust, cardboard and fly ash were used as reactive materials in laboratory studies. Sawdust was obtained from oak and fir-wood while fly ash from heating station Bor, bitter-oak and oak. Experiments were carried out using real Saraka stream wastewaters and the degree of removal for iron, copper, manganese and zinc was investigated. The content of these heavy metals in Saraka stream wastewaters was under the limit of III and IV class of water (Law on Water - Official Register of the Republic of Serbia). Parameters such as flow rate of water, pH and effluent volume, contact time between water and reactive material, etc, were monitored during the experiments. All used materials give satisfactory results for iron and other heavy metals removal; the highest degree of removal was obtained by using fly ash.

Jan 1, 2006

By Edward J. Miller

Explosions and fires are without a doubt two of the most feared occurrences in modern underground mines. When they result in loss of life or substantial property damage, they usually gain world-wide media attention and have, on occasion, provided the impetus for legislative action. The very involvement of the Federal Government in mining was the result of a series of explosions which resulted in the loss of hundreds of lives. Fortunately, explosions of this magnitude are rare. Fires and explosions of lesser consequence are, however, more common and their severity may be more a matter of luck than anything else. The publicity which these events receive is usually restricted to the area immediately surrounding the mine and a1 though MSHA and sometimes the state prepare reports of their investigations, the general mining community is quite often aware of the circumstances surrounding these occurrences. This paper will discuss some of these "lesser" explosions which have occurred recently. These explosions have sometimes occurred in sealed or otherwise inaccessible areas of the mine involved, where conventional ignition sources such as electrical power were not present.

Jan 1, 1987