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By Eugene R. Palowitch

From the late 1880s to the present, the Appalachian region continues to be a dominant supplier of premium-quality coals. The region contains an estimated 93.4 Gt (102.7 billion st) of demonstrated reserves in Alabama, eastern Kentucky, Maryland, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia. Therefore, Appalachia will remain a source of quality coals for the metallurgical, export and utility markets. Figure 1 shows the annual production of coal in Appalachia and nationally from 1970 through 1993 (Energy Information Administration, 1994). During that 23-year period, annual domestic coal production almost doubled. Coal production from Appalachia increased at an average annual rate of only 0.7%. Coal production remained essentially constant at about 409 Mt/a (450 million stpy). Thus, Appalachia's market share decreased from 69.8% in 1970 to 47.2% in 1993 - a drop of almost one-third (Energy Information Administration, 1994).

Jan 1, 1995

By P. Bevilacqua, G. Ferrara

Hydrocyclones and other dynamic separators are normally fed with pulps consisting of water and solid particles. The solids usually consist of particles of different sizes, shapes and densities. Except in the special case of monocharacteristic particles, the particles are segregated by these differences in size, shape and density. Segregation is magnified by the high values of centrifugal acceleration in the hydrocyclones. This paper develops a segregation theory that indicates the major variables involved. Experimental data on segregation under different operating conditions for mixtures of magnetite and/or ferrosilicon and nonmagnetic minerals are reported.

Jan 1, 1997

By Karl W. Mote, R. K. "Ivan" Urnovitz

One of the Northwest Mining Association's guide-lines is: "If you always do what you've always done, you'll always get what you've always gotten." Another way of saying this is, simply, "when the road curves, don't refuse to turn." Our industry has been roundly criticized for living in the old political world, and, I believe, justifiably so. Until about 20 years ago, members of both houses of Congress deferred to specialists among their members for mining legislation. This was true for all public lands and natural resource issues, and were referred to as the mining bloc, or the timber bloc, or the ranching bloc. We felt safe, and to a large degree, were safe in the sense that western members of the US House of Representatives and of the US Senate understood the need for multiple use of public lands, and the need for the natural resources they supply. They also knew what it takes to stay in business and how to create the economic atmosphere that encourages private industry to find and provide the natural resources. Almost daily, members of our industry bemoan the destructive effects that current regulations, let alone new proposals, are having on American industry. And, there are some intriguing aspects for us to ponder. First, the specific complaint about the government is not regulation per se, but rather that the rules or policies don't make sense. We recognize that few understand our industry, but we have assumed that the government will rely on people experienced and knowledgeable in the area being brought under government controls. There was a time that this assumption was valid, but it is no longer true since we have entered the era of the professional regulator. Much like the MBA who believes that a professional manager can manage anywhere, the new breed of regulator sincerely believes that process is the key to developing effective regulations or programs. They reason the process virtually assures that all the pertinent facts will inevitably come to light and, after receiving appropriate considerations, will result in the proper decision being reached and implemented. Unfortunately, following the process also allows politics to play a new and greater role than ever before, since information based on what can only be called weird-science can now be presented to the professional regulator and accepted as fact. Regulators do not have the background to question the basic tenets of the conclusion being presented to them. To add insult to injury, testimony from people in the industry involved, intended to set the record straight, is too easily discounted as being merely self-serving. A second aspect is that the question of why the associations aren't doing more to stop poorly conceived legislative and regulatory proposals, or to counter the ever-increasing influence of the selfappointed public interest groups is being increasingly discussed. This is occurring despite the fact that there is a higher level of involvement and closer cooperation between the various associations than ever before. This raises a most important question: where are we going wrong? In the last 20 years or so, major changes have taken place. A new philosophy, taking advantage of the public's recognition of need to protect our environment, has swept through the nation, resulting in a whole new body of law enacted to assure environmental protection. We all acknowledge the need to prevent undue degradation during the course of mineral development, and we all consider ourselves to be responsible stewards of the land, because we live and work in the outdoors and know the importance of environmental protection. The changes in the federal statutes apply now to every aspect of mineral discovery, development, and production, and assure adequate reclamation of lands when we are done. Along with the positive changes, are a constant barrage of attempts to stop public land use, or stop mining, or stop any new economic development, ostensibly to "protect the environment," but often reflecting a hidden agenda of social reform. These types of extreme, irrational, and just plain impossible proposals are everyday occurrences, but we have not geared up to challenge all the proposals which could end mining. Instead, we did what we always had done. The road turned, but we didn't. And we wondered why those who had always protected mining weren't doing their job, and why we were having such limited success in reining in the regulators. The Congress had changed, the public demands had changed, the recognition of importance of natural resources had

Jan 1, 1991

By Joseph B. Gillenwater

Miss Gertrude Carey lived next to us in Martinsburg, West Virginia for several years. She was a retired school teacher. She was also a cousin to Messers Dan and Joe Baker who owned and operated Standard Lime and Stone Company, a predecessor of Martin Marietta Corporation. She-was well acquainted with the Baker family and their history. Here is one of the legends she told my wife, Jean, and me. The Bakers were originally Tanners. They had a tannery near Frederick, Maryland. There were several boys in the family and when they were grown each man had specified responsibilities. Will Baker was assigned the duty of locating, buying, and transporting tanbark and lime. As he traveled through Maryland, Virginia, Pennsylvania, and West Virginia to locate and buy tanbark, he also talked the farmers out of some pieces of lime, which the farmers had produced in holes dug and filled with layers of limestone and wood. Will Baker took the lime and soaked a piece of hide in the milk of lime. If the lime did not spot the hide, Will Baker would get the farmer to burn some lime for him, and further tests would be made. If these tests were good - the Bakers bought the land. They eventually discovered that the limestone that would make lime that wouldn't spot the hide would also be suitable for producing steel. They began producing lime just outside Harpers Ferry, West Virginia in pots and upright kilns. That stone too small for the kilns was just perfect for railroad ballast. Now you know how "Baltimore Blue Bloods" got together!!

Jan 1, 1979

By Peter V. Avotins

During last year's AIME meeting in New Orleans, Deepak Malhotra and I were discussing some of the topics that would be presented in this Symposium. It seemed appropriate that along with papers on specific reagent and flocculant types, we should address research management aspects of new product development. This development is a long, arduous task that requires a significant technical and fiscal commitment by the chemical company and potential users. A flow chart depicting the research process is shown in Figure 1. The sequence of events are plotted on an undefined time line. Our experience has shown that it takes 3-5 years to complete a typical reagent development project. A new project starts with an idea of how to do something better. The ideas range from relatively simple product modifications to opportunities created by technological change. An example of this is the use of flocculants in tailings operations to close the water recycle loop. The change was brought about by the need to conserve water and comply with environmental statutes. The result was the development and wide-spread use of synthetic polymers to help in solid-liquid separation. More recently the ups and downs of oil prices have led to development of coal water slurries as an alternative to fuel oil. The slurries contain high levels of chemicals (up to 3%) to insure proper stability and burn characteristics. There are technical changes under way right now that may lead to ideas for other new products. One exciting source of new technology is the ability to manipulate genetic material of microbes to select for specific capabilities. This has evolved by leaps and bounds over the past 5 years. Biologically assisted leaching and removal of wastewater impurities are two possible end uses. I'm sure that there are many others. The ideas can originate anywhere and are often half-baked at first, but to lead to new products they must be refined to provide project definition and eventually a research plan. A chemical ,development project cannot be started without approval to commit the company's resources. The internal selling job is often very difficult. The company must see clear financial benefits in order to launch efforts that may not pay off for many years. It is critical to project the total market, profitability, eventual market share, and timing of introduction of the new product. There is much uncertainty in this and the research manager is often skating on thin ice to retain his credibility. Once we obtain support from upper management, the research team is assembled to start the project. The teams generally consist of organic chemists, research metallurgists, and technicians. They have access to analytical scientists and technicians for surface and analytical chemistry. The projects are often augmented by help from university staff and consultants. This is particularly true where there is a need to develop fundamental understanding of the technology in addition to synthesis of chemicals. The project now proceeds along two lines. First, there is an emphasis on understanding the prior art. Extensive literature and patent searches are undertaken to provide research leads and to keep from "reinventing the wheel" and infringing on someone else's patent. The scientists and technologists are qualified to conduct computer-assisted library searches. This process usually uncovers 80-90% of the relevant information. The remainder is very much harder to get and requires the help of professional library search staff with scientific backgrounds. Along with literature searching, the team begins synthesis of new compounds. These are screened by use of techniques such as microflotation or filtration in a Buchner funnel. The scientists are looking for the direction of response as they modify structural features . Inevitably, a large number of candidates reach the next stage, a laboratory bench test. At this point it is possible to set up a research plan and use project management techniques to monitor progress. The bench tests are conducted in larger equipment, usually requiring 100-1000 grams of test substrate. Typical laboratory flotation tests are run in Denver or Wemco cells.

Jan 1, 1986

By Antoni Kalukiewicz

From 1997 through 2000, a team of Polish experts headed by the author studied the prospects of mining newly discovered emerald deposits in Afghanistan. This article describes the scheme for mechanization of the mining operations, along with improvements made to the ventilation facilities and lighting. The required equipment was flown to Afghanistan and the Afghan miners were trained in machine operation and maintenance.

Jan 1, 2005

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 H. S. Rathor

NTPC (National Thermal Power Corporation), a multi-unit organization, is generating 26% of India’s total power. This power is produced from its 14 coal based stations and 7 gas based stations. NTPC is entering into the business of power-distribution, power-trading, setting up of coal mines and diversification in non-conventional energy sector as well. For achieving the goal of the country “Power for All” NTPC has taken a giant stride by entering into Hydro Power generation which is also the cheapest and the cleanest renewable source of energy. In its pursuit for excellence, 800 MW Koldam Hydro Power Project is NTPC’s first venture in hydro sector. In Koldam, hydropower potential will be harnessed by constructing a 163m high earth and rock fill dam in a narrow gorge at upstream end of Bhakra reservoir. The river diversion is envisaged through two parallel, 14m finished diameter ‘horseshoe’ tunnels of length 901m and 934m at village Kian on the right bank, where the river forms a 180° loop. The diversion tunnels are designed to accommodate a flood of 6500m3/sec, taking into account the maximum probable discharge of 200 years return period. The tunnels pass through dolomite and limestone rock formations. The excavation of tunnels was done with drill and blast method. The excavation was attempted from both inlet and outlet faces. During geological investigation a rock fault was located at the outlet area. The location of the fault was such that it was passing through the edge of the Tunnel-1portal and around 30m away from the face of the Tunnel-2 portal. The quality of the rock at Inlet was also poor. To save the portals from slips, excavation of the tunnels was planned to start after the completion of the open excavation and its support system both at inlet and outlet. The tunnel excavation at inlet was envisaged by approaching the tunnels’ portal by constructing a road through 540EL bench and meeting the inlet portals on the upstream end, which would have been ready by mid2003, only after completion of the open excavation and its support system. To save time and cost, it was felt necessary to modify the planning by starting the tunnel excavation simultaneously along with open works both at inlet and outlet. The excavation at the inlet face of the tunnels started in December 2002 after rerouting the approach road to inlet portals through haulage road on the downstream and similarly Tunnel-1 at the outlet was started in the low cover area before completion of open area works. Thus the tunnel—heading excavation was started nearly 06 months early with the change of methodology.

Jan 1, 2005

By Jerry Grott

Southwest Salt Company is solution mining the Luke Salt Body of probable late Miocene age. The discovery hole, from which the first core was recovered, was drilled in 1968. The deposit was encountered at a depth of 880 feet, and the bit was still in salt at the bottom-hole depth of 4,500 feet. The solar ponds, developed on land formerly dedicated to agriculture, have an annual capacity of about 90,000 tons. Because land values are very high, mining rates and procedures are governed by the need for near-saturated brine to minimize land requirements. Because of the frequency of dust storms, the salt operation uses a unique wet-harvesting method. Most inventory is kept in the ponds under brine and harvested only a few days before shipment. Studies of the nature of crystal growth and the distribution of windblown and brine impurities led to the development of procedures for processing salt of high chemical purity and low insolubles content. Chemical purity exceeds that of most salt produced in fuel-fired evaporators. Salt is shipped from Phoenix as tar east as west Texas and as far west as central California. Occasional shipments have been made to Hawaii and Alaska.

Jan 1, 1987

By John R. Wright

This paper reviews the increased use of mechanization in order to develop lateral headings efficiently and economically. Particular emphasis is placed on the role of the Electric-Hydraulic Drill Jumbo in achieving this goal. Also, the use of modified mining equipment to suit various operating conditions is discussed.

Jan 1, 1981

By Laura McNally

In 2006 McNally International Inc. in a Joint Venture partnership with Aecon Constructors was the successful bidder on two York Region Tunnel Projects: Bathurst Collector/Langstaff Trunk Sewers; and YDSS Interceptor Sewer 19th Avenue Project. These projects comprise a total of 13 kilometres of 2.74 meter finished diameter tunnels and are both part of the York Durham Sewer System (YDSS). Both contracts require the use of EPB tunnel boring machines with a precast concrete segmental liner. The following provides an overview the two projects.

Jan 1, 2008

By M. E. Lewellyn

A lower moisture content for a clean coal product means increased Btu content, or increased yields at the same Btu content, and lower operating costs. The conventional surfactant-based dewatering aids effeciently lower the moisture content but often the presence of residual surfactant in the filtrate and recycle water causes problems downstream. ACCOAL-DRI 1000, a surfactant-based dewatering aid, was developed to solve this problem by minimizing the downstream effects while efficiently lowering the moisture content. The theory of the use of surfactants in filtration will be discussed as well as the development and field evaluation of this new product.

Jan 1, 1988

By Ronald Allum

Arizona leads all other states in the value of gemstones produced with an annual production which exceeds $3,000,000. Gemstones are an important component of the mineral wealth of the State. Turquoise, peridot, chrysocoll a, petrified wood, fire agate and crystallized mineral specimens are among the gemstones commercially mined. Numerous additional deposits are operated by hobbyists. The State's reputation as a source of gemstones and specimens for the collector and lapidary adds to the economy of the State by attracting tourists. Production of gemstones further adds to the State's economy through employment in the value added gemstone processing industries and by employment of Native American craftsmen.

Jan 1, 1988

By D. Robert Weir

The pioneers in pressure hydrometallurgy have provided a solid foundation during the past four decades. The pressure techniques are now capable of being used to push back the frontiers in the winning of metals. Pressure hydrometallurgy has been used to meet the objectives of extracting metals; purifying metal solutions, recovering metals; and rendering waste streams acceptable for disposal to waste repositories and the environment. Some examples of each of these functions are briefly reviewed. The applicability of pressure techniques to the recovery of precious metals is discussed.

Jan 1, 1985

By M. C. Roberts

Currently, mineral producers are suffering through a major downturn in prices for their products, even though it has only been a few years since they were enjoying high prices. From an historical perspective, the current situation is another of the cyclical down-turns that often reoccur every 5 to 7 years or so. This paper uses time trend decomposition techniques to identify the cycles and statistical methods to find the duration of these cycles for a variety of mineral prices. Given some idea of how long and severe these cycles typically are, the mining industry can better plan to weather the downturns and take advantage of the upturns. For example, timing investments in new projects to take advantage of the cyclical upturns can dramatically improve project profitability.

Jan 1, 2000

By Pat Wilmoth, Joseph P. Gildner, Dan Nowak, Shane Yanagisawa, Don Z. Painter, Gordon F. Revey

Frontier/Traylor is presently completing construction of twin tunnels for the Tri-County Metropolitan Transit District of Oregon’s (Tri-Met) westside lightrail system. The tunnels are each 4,550 m (14,935 ft) in length and 6.48 m (21.29 ft) in diameter. The 1/3 of each tunnel was driven from the west portal using drill and blast methods and the remaining 2/3 was driven from the east portal using a TBM. The paper describes: The difficulties encountered by the TBM mining the weathered Columbia River Basalts. The execution of drill and blast work despite challenging ground conditions, stringent noise and vibrations specifications, and public relations problems. The excavation and lining of the Washington Park Station 79 m (260 ft) below the park zoo.

Jan 1, 1997

By M. C. Roberts

Metal producers are now suffering through a major downturn in prices for their products even though it has only been a few years since they were enjoying high prices. From an historical perspective, the current situation is another of the cyclical downturns that often occur every five to seven years. This paper uses time-trend decomposition techniques to identify the cycles and statistical methods to find the duration of these cycles for a variety of metal prices. Given some idea of how long and severe these cycles typically are, the mining industry can better plan to weather the downturns and take advantage of the upturns. For example, timing investments in new projects to take advantage of the cyclical upturns can dramatically improve project profitability.

Jan 1, 2003

By Guillermo P. Selas

Perhaps this is the first time that an analysis of the industrial minerals panorama has been made in Mexico for that type of commodities. Because the non-metallic minerals lack the glamour of the metallic minerals and are usually of less unit value than metallics, a comparative study of these commodities has seldom been attempted. Sulphur, fluorite, barite and few others are an exception. Consequently, the statistics on the lowest per unit value industrial minerals, such as limestone, dolomite, gravels, sands, etc., are usually scarce and not always accurate. The following, then, will be an attempt to show a general status of the industrial minerals in Mexico with due reservations regarding volumes and values. According to Kruger (1971), this group of minerals surprisingly very little known, and called non-metallics because the lack of metallic luster, is the largest group of the mineral kingdom. It constitutes perhaps 75% of all the mineral varieties. For the most part, these minerals are compounds of common acids, sulphides, hydroxides and two elements carbon and sulphur. The list of non-metallic minerals is therefore very long. It includes the borates, carbonates, chlorides, fluorides, nitrates, phosphates, silicates, sulphates and less commonly arsenates, chromates, molybdates, sulphides, tungstates and vanadates. The latter group and many of the oxides are sought usually for their metal content.

Jan 1, 1974

By C. Ottergren

A process does not have higher capacity than what can pass through its bottleneck. Acknowledging this, and with the goal to optimize production at a minimum investment, one can use existing equipment, modify the process flow and make a few strategic capital investments. Automatic setting regulation is a technology that allows balanced crusher performance matching minute changes in feed material characteristics. The system makes it possible to utilize the crushers fully at all times. It also continuously and completely compensates for manganese liner wear.

Jan 1, 1999

By A. C. Lordi

Present industrial plant design is influenced by motivators beyond the usual powerful one, creativity, on which Consultants thrive. The respected, although annoying, ever-present Return on Invested Capital becomes even more significant with anticipated escalation. Government regulations are having an increasing influence as air and water protection, sound and electrical safety requirements must be met And more recently, the increasing cost and uncertain availability of energy sources are having a revolutionary affect on plant design. More than ever before, the Consulting Engineer is faced with requirements and restrictions which tax even the most original thinkers -- and the result is good. This paper includes a brief review of recent trends in Cement Plant Engineering Design.

Jan 1, 1975