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By George W. Parker

The ever increasing costs of labor and supplies have made it imperative that operators of open pits look for some way in which to cope with these increases. One of the most logical ways to increase the efficiency of an operation is by the introduction of larger haulage equipment, as generally haulage costs are the greater portion of the over all expenses. These larger haulage units require larger shovel units. In the late 1930's and the early 1940's large mining, quarrying and heavy construction operations had more or less standardized on the 4 to 6 cubic yard shovels. During this same period the haulage units were generally 22 to 27 tons. Some ten years ago 9 - 13 cubic yard shovels along with plus 50 ton haulage units were introduced by manufacturers in an effort to enable operators to decrease costs.

Jan 1, 1962

By David S. Smith

Almost nine years after the assertion of enormous and pervasive federal control over coal mines by means of the Federal Coal Mine Safety and Health Act of 1969, 30 USC Section 801 et seq, as amended by the Federal Mine Safety and Health Act of 1977 (which basically increases the punitive powers of government) a brief assessment of some of the underlying causes, present status, and possible alternatives to governmental control is appropriate. In a governmental system based upon the principles of democracy and the protection of individual freedoms and constitutional rights the ultimate mechanism for abrogation of these rights is the creation and exploitation of fear. Machiavelli in rendering advice concerning the power over men provided by fear stated, "... it is much safer to be feared than loved .. fear preserves (the government) by a dread of punishment which never fails." The Prince. Within the context of the assumption of control by the government over industries or segments of our population - popular fear provides a convenient and almost necessary mechanism for the avoidance by law or regulation of democratic principles. The popular fear of coal mines has been successfully exploited by various goal oriented groups in the past and most recently by a Congressional constituency with a vested interest in controlling the mines through regulation.

Jan 1, 1979

By David Wilson, T. V. Rao

INTRODUCTION The Alchem trona mine, owned and operated by Allied Chemical Corp., is located approximately 32 km (20 miles) west of the town of Green River, and 8 km (5 miles) north of Interstate 80 in southwest Wyoming. Trona, a naturally occuring sodium sesquicarbonate (NaCO3 • NaHCO3 • 2H2O), is used for the production of sodium carbonate (Na2CO3), commonly known as soda ash. Present annual US consumption of soda ash is approximately 9.07 Mt (10 million st), out of which approximately 7.3 Mt (8 million st) is produced from the Wyoming trona mines. About 44% of soda ash is consumed by the glass industry; 3 % by exports; and the remaining portion by paper, chemical, soap, textile, and nonferrous industries. Allied Chemical operates an underground mine at an average depth of about 488 m (1600 ft). There are three other trona mines in the area operated by FMC Corp., Stauffer Chemical Corp., and Texasgulf Inc. (see Fig. 1). Allied Chemical became interested in southwest Wyoming trona deposits in the early 1940s. Explora¬tion work was begun in 1959 with the acquisition of federal leases. Exploitation of the reserves began in 1968. Two shafts, one 6.1 m (20 ft) and another 3.7 m (12 ft), were completed prior to 1968. The 6.1-m (20-ft) diam service shaft is divided in half by a cur¬tain wall, with one half used for men and material and the other for ventilation as a return air shaft. During the period from 1968 to 1974, the 3.7-m (12-ft) shaft was used as production shaft with two 7.3-t (8-st) skips. Due to the increased demand for soda ash, plant and mine expansions were completed during 1974. Under this expansion, the material handling system capacity was increased by constructing a new 2721-t (3000-st) capacity ore bin, sinking a 6.1-m (20-ft) diam produc¬tion shaft, and installing a friction hoist with two 22.7-t (25-st) skips. The Alchem mine manpower is 484 employees and about 2.3 Mt (2.5 million st) of trona was produced during 1976. Three different mining systems are used at the Alchem mine: conventional, continuous, and longwall. Allied Chemical introduced its first longwall unit in 1973, which was also the first longwall system introduced in the Wyoming trona district. At present, four conventional, seven continuous, and two longwall units are in operation. This equipment is operated in ten production areas. GEOLOGY The bedded trona and trona-halite in the Green River basin of southwestern Wyoming is a major re¬source for the nation. There are 25 beds that exceed 0.9 m (3 ft) in thickness and underlie areas of about 2590 km2 (1000 sq miles). There are other minor beds that range in thickness from 0.3 to 1.2 m (1 to 4 ft). Allied Chemical's Alchem mine is located in bed 17. The trona bed numbering system starts at the lowest elevation and increases upwards. The trona beds are in the Wilkens Peak member of the Green River formation. The Green River formation was deposited in a lake that began in early Eocene as a large body of fresh water, shrank in size and became saline, and then became fresh water again. The sedi¬ment during the saline phase of the lake, which includes the trona beds, is called the Wilkens Peak member. The underlying freshwater lake deposit is called the Tipton member and includes a 25.9-m (85-ft) sand unit which is a high pressure, low permeability aquifer. The over¬lying sediment is called the Laney shale. The Green River formation is underlaid by the Wasatch formation and overlaid by the Bridger formation (see Fig. 2). The structure of the beds in the area of the Allied Chemical mine is mostly postdepositional asymmetrical folds of small amplitude. These folds range in size of 3 to 6.1 m (10 to 20 ft) to as much as 45.7 m (150 ft). The trend of the folds is northwesterly with the north¬east flank of the anticlines having a steep dip and the southwest having gentle dips. Trona bed 17 varies in thickness from 2.4 to 3.4 m (8 to 11 ft) over the 93.2 km2 (36 sq miles) holdings of Allied Chemical and is flat lying except for the rela¬tively minor folding and a negligible regional dip of about 0.017 rad (1°). Trona occurs naturally in several physical forms in the Green River basin, being both massive and crystal¬line. The trona ore in the Alchem mine is a fine-grained massive ore with a compressive strength of approxi-

Jan 1, 1982

By P. Ritsopoulos, A. J. Dentsoras

The objective of this paper is the development of a reliable simulation model for the operation and production capacity of an aggregates quarry. Based on this model, a computer program is introduced that provides the final production outputs according to the defined material gradation and machinery characteristics. The program takes into consideration all operational parameters that may be introduced by the user through the whole machinery network. As a result, all production parameters are properly updated. The structured simulation program can help detect production inefficiencies that result from design ineffectiveness. Additionally, the program can be used for the generation of alternative scenarios for future modifications of a plant's configuration. Finally, a designer can use it as a tool for obtaining optimum solutions concerning newly designed quarries. As a case study, a quarry operating at Heraklion, Crete, was examined. The application of the program to the plant produced a complete image of the quarry's input/output characteristics, along with some suggestions for improvements on certain production processes.

Jan 1, 1998

By Grover H. Emrich

Pennsylvania,, due to its location in the humid east, is fortunate to possess within its borders large quantities of water. Most of the State is drained by three major river systems-the Ohio, Susquehanna and Delaware. This abundant supply of surface water has been widely utilized throughout the State, but today other sources of water must be developed due to the increasing demands for water, die largest undeveloped source of water in Pennsylvania is ground water. Pennsylvania is also fortunate to possess extensive coal resources. These coal resources have contributed measurably to the development and prosperity of the States Coal and water's - two valuable resources - have been necessary for the development and industrialization of Pennsylvania, The State needs both resources but can no longer afford to develop one while adversely affecting or destroying the other, We are aware of the effect of coal mining on surface water, but coal mining can also materially affect subsurface water, This effect will according' to the local geologic conditions.

Jan 1, 1965

By G. C. Tipper, A. P. Deane, A. G. Myers

SCHEME DESIGN London’s Heathrow Airport, as the world’s busiest international airport, is missing one vital aspect - a dedicated rail link which connects directly to the city. All this is about to change with the construction of Heathrow Express - a fast, high quality rail service between the airport and the centre of London. It was recognised in the mid 1980s that if Heathrow was to accommodate the forecast growth in passenger numbers and the resulting increase in road traffic, a dedicated airport rail service would be vital. The main access into the centre of Heathrow is via a road tunnel with a direct link to the M4 motorway. The airport has introduced a number of traffic management schemes, but these can only achieve so much benefit. Growth in air passenger traffic is predicted to continue at an average of 4% per annum well into the next century and it was clear that significant investment was needed. Heathrow Express at a cost of over £350 million will provide this when it starts its service in June 1998. The business case for the scheme is based on a rider ship of around 15% of air passenger traffic. The initial Heathrow Express service will be based on four trains per hour, up to 8 car train lengths, providing a high speed non-stop service between the airport and central London in just 16 minutes. Initially a joint venture between the British Railways Board and Heathrow Airport, by mutual consent of the two parties, Heathrow Airport recently purchased the British Railways Board share making this one of the largest private sector rail projects currently under construction in the UK. Leaving Paddington, the main rail terminus in West London, Heathrow Express trains will travel 12 miles on the newly electrified line to airport junction, north of the airport. At this point they will leave the mainline to enter a 5 mile tunnel section that runs underneath the heart of the airport. The railway companies are responsible for track work, signalling and electrification of the 12 mile main line section including a grade separated junction over the main tracks for the Great Western Railway which links London and South Wales. Heathrow Airport is re-

Jan 1, 1997

By George K. Martin

This paper deals primarily with roof bolting in Kentucky coal mines from January 1, 1949, through December 31, 1954, a six year period. The Consolidation Coal Co? (Ky.), a division of the Pittsburgh Consolidation Coal Co., began systemmatic roof bolting in November 1948 in Mine #204, Elkhorn #3 Seam, at Jenkins, Kentucky, After the efficiency of roof bolting had been proven by the Consolidation Coal Co., this procedure was adopted by other companies throughout the state. In December 1954, approximately 46.4 percent of Kentucky's total production of coal from underground mines was obtained from roof-bolted areas. Statistics in this report will show the progress made in roof bolting during the six years, in addition to the roof bolting being done as of December 31, 1955. Significant progress has been made in the coal mines of Kentucky in reducing the roof-fall fatality, rates, during the past several years by adopting systemmatic roof bolting. The ground work by the Consolidation Coal Co, (Ky.) in cooperation with the Federal Bureau of Mines was based upon the previous experience of the St. Joseph Lead. Cc, in its Southeastern Missouri Mines and The Tennessee Coal and Iron Division of the United States Steel Corporation. The author gratefully acknowledges the cooperation and assistance given by officials of the various mining firms using roof bolts, the Kentucky Department of Mines and Minerals, and the Federal Bureau of Mines in furnishing photographs and information.

Jan 1, 1958

By Y. J. Wang

The definitions of system pressure loss (mine head) and system resistance, which are traditionally associated with single-fan net- works, are applied to multiple-fan ventilation networks. The system characteristics -- relations among air power, pressure loss, air quantity and resistance -- are analyzed by introducing the concept of subsystems. These subsystems are associated with the fans located in a cutset of the network. For a multiple-fan network, the resistances for the subsystems and total system are dependent on the quantity ratios of the subsystems. In general the pressure loss of a subsystem or a total system does not vary as the square of the corresponding air quantity. If the quantity ratios of subsystems are all held constant, then the resistances become constant and the pressure losses are predictable from the quantities employing the "square law." The system resistance has a minimum value under the natural- splitting flow pattern. Being independent of the value of system quantity, the minimum system resistance provides a basis for comparing the different networks.

Jan 1, 1983

By M. A. Kaufman

In this paper I will attempt to present an up to date review of the type of exploration' that has previously been carried out in Alaska, discuss some of the more significant past producers and recent discoveries, and suggest some approaches to future exploration. Hopefully this information may be of some use to those parties tempting to evaluate Alaska's non ferrous, non placer, metal potential or contemplating initiation of exploration in the state. II. SUMMARY AND CONCLUSIONS Past production of non ferrous metals from lode deposits in Alaska has been meager considering the size of the state. Since there have been no major lode mines operative in Alaska since World War II, and since logistical conditions vary throughout the state, it is not possible to generalize with respect to mining costs in Alaska as compared to those in other areas. There seems to be little question, however, that a major deposit situated in a reasonably favorable location' could be profitably operating at present. Host of the known metal prospects in Alaska were discovered by early gold prospectors prior to World War I. From World War I through World War II exploration consisted chiefly of surface prospecting by prospectors on a diminished scale, as compared to the early gold rush days, drilling of some prospects by the U.S.B.M,, and occasional mine or prospect evaluations by mining companies. From the end of World War II to the present time, there has been a generally steady increase in exploration by mining companies consisting chiefly of prospect and district evaluations, large scale aerial reconnaissance programs in search of color anomalies, and regional drainage geochemical surveys. The post World War II increase in mining company exploration has not been matched by an increase in conventional surface prospecting.

Jan 1, 1972

By L. F. McHugh

Molybdenum conversion operations discussed in this paper encompass all major operations commercially used to upgrade molybdenite concentrates to various refined products. More emphasis is placed on discussion of key pyrometallurgical unit operations. These operations conducted at Metec include roasting, sublimation, and hydrogen reduction

Jan 1, 1986

By Carl F. Austin

The subject of strata control in mining can be approached from both static or loading concepts or from dynamic or impulsive loading concepts. The fracture process itself appears to be primarily a dynamic process as is the gross creation of fractures through the use of impact, stress wave passage or in more general terms, the use of explosives. This paper presents experimental results which indicate that the understanding of the fracture behavior of rock that has been, established in the open literature is not always appropriate. In particular, the results of this experimental program have shown very interesting differences between the formation of fractures in rock and the formation of fractures in other materials such as metals and plastics which are often used as models for rock behavior studies Fracture patterns and causes of dynamic fracturing in various rock and artificial materials are presented.

Jan 1, 1965

By Henry Chajet

Good morning, it is truly an honor to have been invited to speak before you today Before I begin my update on MSHA's activities, I?d Like t o quickly say a few words about the American mining congress and its mission in Washington, AMC is a national trade association representing most of the producers of the nation's metals, nonmetals and coal, we also represent the manufacturers of mining equipment and supplies and the financial and consulting institutions which service the mining industry. It is the diversity of our representation which gives us our greatest strength in our petitioning efforts, the administration and the members of congress know that an AMC position is the result of the careful consideration of a vastly diverse group of mining concerns. Our president, Al Overton, perhaps has the best description of AMC when he speaks of us as "the mining industry's eyes and ears and its collective voice in Washington."

Jan 1, 1981

By J. C. Agarwal

A significant portion of the, coal mined by U. S. Steel is beneficiated to upgrade the quality of the resultant coke to meet blast-furnace requirements. Primarily because of degradation from modern mechanized mining methods, a considerable quantity of the coal to be beneficiated is in the 1/4-inch by 100-mesh size range. In the cleaning plants, this coal is usually cleaned on concentrating tables and then mechanically dewatered in solid-bowl centrifuges to 9 to 14 percent water. At some plants, to further decrease the amount of water shipped with coal, and to improve the coking characteristics of the coal at its destination, mechanical dewatering is followed by thermal drying. At U. S. Steel's-Alpheus preparation plant at Gary, West Virginia, approximately 50 percent of the total coal produced is in this fine size range, and two fluidized-bed dryers are used for the thermal drying step. The two fluidized-bed dryers are 14 feet in diameter and were designed by the Dorr-Oliver Company. Although the original design called for a rate of drying equivalent to 37 tons, of moisture per hour, presently they are removing twice that amount. This paper describes, the major problems encountered' in operating these dryers at the present, high capacities and how they were overcome.

Jan 1, 1963

By E. A. Noble

In the Western Coal Region, successful reclamation of surface-mined areas includes the protection of groundwater sources. To accomplish this, a complete understanding of the geohydrology of the affected area is imperative. Successful mine design also calls for careful attention to geohydrology. Because the Western Coal Region is semi-arid land used mainly for farming and grazing, groundwater is a particularly sensitive topic. It is especially sensitive where the lignite scheduled for mining is itself the aquifer supplying the farms and ranches. Such is the case throughout much of the Western Coal Region, particularly where there are no near-surface sand and gravel aquifers that are commonly found in the glaciated portions of the Region. Just as mining can adversely affect groundwater supply, so can groundwater adversely affect mining. Mine flooding and highwall instability are examples of this. But, mine operators must realize that procedures they use to remedy geohydrologically-related mining problems can have a dramatic effect upon ground- water conditions in areas adjacent to the mine. A logical precaution is to require the acquisition of complete baseline data prior to making the first cut. We recommend that the mining plan not only incorporate the reclamation plan, but that they be developed as one plan.

Jan 1, 1976

By Henning E. Soderberg

Yesterday, air pollution was somebody else's problem -- today, it is everybody's problem. The coal industry with thermal coal drying, is aware of their problem and the necessity of doing an acceptable job; however, there is much to be said as to how good a job is required and what performance limits should be set up. American Air Filter Company has been one of the pioneers in the solution of the thermal coal dryer dust problems, Because of high moisture content, products of combustion and occasional temperature surges, only wet collection has been considered as the practical approach. Our first installation goes back some 12 years with a total to date of 29 Individual wet collectors, each, fabricated of suitable corrosion-resistant material, at 14 operating plants. To eliminate a potential air pollution problem, a performance requirement of not more than approximately one-quarter (1/4) grains per cubic foot in the dust collector discharge was used. In nearly all installations, operating performance surpassed requirements, but discharge stacks were not entirely free of discoloration. However, plant nuisance and air pollution complaints were eliminated. This satisfactory performance was accomplished by medium priced wet dust collectors operating at a 4-6" W.G. pressure drop with cater drain requirements of about 1 gallon of drain water per 1000 cubic feet of air exhausted.

Jan 1, 1962

By P. Michael

Proponents of geomorphic mine land reclamation have criticized current reclamation practices in the coal fields of steep-sloped Central Appalachia as too narrowly focused on civil engineering principles and neglectful of the functional and aesthetic benefits of reclaiming mine sites in ways that mimic natural landforms and drainage patterns. They observe that current mining and reclamation practices are radically transforming the mountain-and-valley terrain into gigantic flat plateaus and, in doing so, disrupting the beauty and ecology of the natural landscape. Instead of designing and constructing linear or planar surfaces and unvarying slope gradients during the reclamation process, they recommend ?landforming,? i.e. the adoption of curvilinear, compound slope forms that blend well with the surrounding physiography and represent the result of naturally stabilizing geomomorphic processes. The authors feel that the concept of geomorphic mine land reclamation is sound, however, its application to the Central Appalachian coal fields faces significant--albeit not insurmountable--challenges. They include: (1) existing reclamation enforcement regulations that are focused on civil engineering principles and not explicitly supportive of geomorphic methodologies; (2) regulatory agencies? current intent to limit the down-gradient reach of excess spoil fills in order to allay disruption or burial of natural streams; (3) actual or perceived increases in reclamation costs; and (4) the challenge of designing and constructing ?natural? landforms that are mature and stable in an otherwise youthful, erosional landscape.

Jan 1, 2010

By John E. Husted

Universities have education as their primary purpose. This appears to be an innocuous statement with simple meaning. In an age of conflicting semantics, however, cords and meanings are often lost or changed. The term education is often broadly expanded to encompass any form of learning process, or the accumulation of knowledge, and even to the beneficial application of knowledge to man's problems, hence one find that education in universities is not solely the formal process of texts, lectures, recitations, and testing by a batch process known as class room teaching. Despite critics of education batch is spelled with an "a", instead of an "o" - at least we hope so If one defines teaching as causing to learn, then the learning objectives may necessitate a variety of approaches within the teaching concept and research is among those favored at the graduate and some undergraduate levels. Research has been among the glamour words and certain fields such as oceanography and space science have had more than their share of glamour. Unfortunately, industrial mineral research has not had the competitive drawing power of enamoring students of the "note" generation in terms of glamorous accomplishment. Research today usually requires sophisticated equipment and such equipment is expensive, both for initial purchase and operation. Again, administrations, be they industrial, government, or academic, usually require

Jan 1, 1970

By H. E. Grand

The purpose of this paper is to outline briefly some basic principles of ground- water hydrology that have application in mine hydrology. The development of a mine below the water table pleads for accurate values to answers of hydrology problems. Such problems involve both an inflow of water without adequate drainage facilities and a deficiency of water for the required use. Methods which give acceptable quantitative values for the solution of many ground-water problems depend on rather simple geologic structures, characterized chiefly by isotropic rocks of considerable areal extent. Unfortunately, mining operations are likely to be centered where isotropic rocks are not present. Consequently, methods that attempt to show values of the storage and transmitting capacity of rocks in mining areas must be applied with caution. In spite of complex geology and apparent uniqueness of individual mines and quarries, adherence to some concepts of ground water used by -hydrologists in the study of behavior of wells should be helpful to mine operators, The work of the Ground Water Branch of the U.S. Geological Survey through its history has been confined largely to the study of ground water as a resource, In view of the increasing number of problems relating to drainage of mines, the Branch started an investigation of mine hydrology in 1945 under the direction of W.T. Stuart, Mr. Stuart and other workers are making detailed studies of specific mine areas. In the present paper an attempt is made to synthesize some facts about ground water into usable form for the typical mine operator. Mining operations that extend below the water table disturb the natural hydrologic regimen, Prior to development, the water table slopes away from the site of a mine in at least one direction, but as soon as development begins and water is removed from the mine, the mine becomes the apex of a depressed cone in the water table, causing a convergence in the flow of water toward the mine. The behavior of the cone of depression, as it tends to deepen and increase in areal extent when the mine deepens, is related to the rate of withdrawal of water necessary to keep the mine dry. The significance and nature of the cone of depression in the vicinity of pumped wells has been studied by ground-water hydrologists for years, but the cone caused by pumping water from mines has generally been less systematically appraised.

Jan 1, 1958

By L. D. Hartzog

A pilot plant investigation of a semi-autogenous mill - ball mill circuit is described. The plant was operated with minus eight-inch diabase as feed material to the semi-autogenous mill. The semi-autogenous mill recycle screen underflow was put to a ball mill in closed circuit with a cyclone. An operating Work Index of 13.3 to 14.9 was obtained with the pilot ball mill. This Index is substantially in agreement with the scalped feed laboratory Work Index for 15.3 for recycle screen underflow. The Bond Index of the diabase was 15.8. Thus, one may use the scalped feed laboratory Work Index to size semi-autogenous grinding plant ball mills.

Jan 1, 1974

By Theodore Balberyszski

The gradual depletion of high-grade sulphide mineral deposits has turned the attention of the mineral industry to the recovery of metals from the oxides and silicates. Anionic (fatty acid) and cationic collectors have in some cases made flotation of non-sulphides possible, although in general, flotation of oxide ores is not as yet an economic process. Consequently, many attempts have been made to sulphidize the surface of the relevant oxide mineral and thus make it amenable to flotation. (1) (2) (3) In recent years, Bautista and Sollenberger(4) have investigated the conversion of a number of oxides to sulphides by reacting them with molten sulpur. This paper presents the results of investigations carried out at the School of Mineral and Metallurgical Engineering at the University of Minnesota to study the flotation characteristics of some sulphidized minerals. It is divided into two parts; Part I describes the sulphidization of a number of oxides and a silicate, and Part II presents the flotation behavior of the products of sulphidization.

Jan 1, 1968