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By R. P. Killmeyer, B. S. Gottfried, J. T. Wizzard

The US Department of Energy's Coal Preparation Branch has developed a computer program to calculate the performance characteristics of coal washing devices. This program uses specific gravity analyses of the clean coal and refuse streams as input, and generates dependent and independent performance criteria for the washer. Partition curves are internally represented in a functional form by a Weibull function. Comparisons are made between performance criteria calculated by hand and the performance criteria calculated by the program for 120 different dense medium cyclone tests. Results show that the computer program gives results in close agreement with hand-calculated values while greatly reducing the amount of time involved in performing the analyses.

Jan 1, 1984

By P. E. Hopkins

In speaking of the economic geology of southeastern Ontario, W. G. Miller and C. W. Knight1 say that "there occurs in southeastern Ontario a variety of minerals and rocks of economic value, probably as great as in any district of like size on the North American continent. Some of these deposits, including marble and trap, are inexhaustible. Others, including talc and iron pyrites, have proved to be of considerable economic importance. From time to time, during the last 50 years, the following minerals and rocks have been mined or quarried with varying success: gold, iron pyrites, zinc blende, copper pyrites, galena, mispickel, magnetite, hematite, talc, actinolite, mica, marble, ophicalcite, feldspar, fluorite, apatite, corundum, graphite and sodalite. All of the economic materials, with, the exception of fluorite, appear to be of pre-Cambrian age. The fluorite veins penetrate the Ordovician, Black River, limestone." Accompanying that report was an article by the writer on the Queens-boro Pyrite Area which includes one of the two working pyrite properties in southeastern Ontario. In the present paper will be given a brief description2 of all the known pyrite deposits in the area which may at some time possess an economic value, with fuller descriptions of the two working mines—The Canadian Sulphur Ore C,o.'s mine near Queensboro, and the Nichols Chemical Co.'s property at Sulphide. The earliest mining of iron pyrites in Ontario was done in 1868 on the Billings property near Brockville. The mines were closed down in 1879 under the assumption that they were exhausted. Many other

Jan 1, 1917

By Paul K. Krueger

SUMMARY Since 1970 the Federal Preparedness Agency has been using computer models to help establish the amounts of strategic and critical materials to be held in the National Stockpile. Fifty-three of these materials are metals or minerals. The following diagram shows the linkage of models used to estimate material requirements. [ ] The starting point for the models are estimates of the major components of GNP for some future period. These may be estimates purchased from a forecasting service or may be produced in-house. The projections are translated into industrial final demands using DITT (Demand Impact Transformation Tables), a system developed at FPA. Then using a version of the current Bureau of Economic Analysis input-output model, estimates are made of the gross output of each industry necessary to support the level and composition of GNP as specified by the macro-economic model.

Jan 1, 1977

By William D. Schwab

In the technical literature of 1965 and 1966, there were several papers about future power for mining and construction equipment. Most of these papers made the same predictions: •More power •Better reliability and durability •Ease of service and maintenance •Operating economy •The possibility of future environmental concern •The entrance of the gas turbine In the five years that have since passed, some of the 1965-66 predictions have at least partially come true, while others have not been fully realized. Actually the list still appears sound today. Priorities may have changed and details may be different, but the main points cover the requirements for future prime movers quite well.

Jan 1, 1971

By William Daly

THE application of artificial refrigeration, or air-conditioning, to the ventilation of deep, hot mines has long been a subject of interest to the operators of such properties. Artificial cooling of the air in theaters, railroad coaches, and various industrial plants has been so successful within recent years that it has been natural to assume that the adoption of similar methods would afford a ready solution to the difficult problem of mine ventilation. It should however, be obvious, that although there may be nothing technically impossible in the application of this process to mine ventilation there is a great economic distinction between the maintenance of a high standard of comfort for a large number of people in a relatively small space such as a theater and the cooling of air to improve working conditions for miners scattered throughout the extensive workings of a large mine. Many methods of air-conditioning have been considered by the management of the Anaconda Copper Mining Co. at various times, but until the development of the process to be described in this paper none has seemed economically practicable.

Jan 1, 1934

By Paul Levin

A coal preparation plant built with conventional materials only might be able to do an efficient job of preparing coal, but its maintenance costs would be high and emergency shutdowns frequent. To remedy this situation special materials are being used, either in original plant construction or for replacement of conventional materials. The special materials vary from high-strength and abrasion-resisting steels and stainless steel alloys to ceramics. They include hard surfacing welding rods, rubber refractories and some of the newer plastics, the merits of which are cited by the author. A coal preparation plant, limited strictly to the use of conventional materials-for example, mild steel, cast iron and ordinary rubber-could, no doubt, do an efficient job of preparing coal, but the high cost of maintenance and increasingly frequent emergency outages would soon force the operator to seek relief by introducing special materials such as alloyed steels, oil-resistant rubbers and hard-surfacing welding rods.

Jan 6, 1964

The 114th (New York) Meeting of the Institute will be held in the third week of February, 1917. The Committee on Papers and Publications has set Dec: 1, 1916; as the closing date for the receipt of manuscripts intended for this meeting. Manuscripts must be received by the Secretary on or before this date. If they are sent through members of the technical committee they must be sent to those committees enough in advance of the time to be forwarded and in the hands of the Secretary by the time specified. While Dec. 1, 1916, is the final closing date, it is a great advantage to get papers in as much before that time as possible as it enables them to be submitted in proof form to their authors. Papers received on or before Nov. 1, 1916, will, as far as possible, be published in the January Bulletin or earlier, thus giving good distribution among the members in advance of tile meeting. The Institute's records show that the discussion of papers is very rnuch better when they are distributed somewhat in advance of the meeting instead of in the Bulletin which goes out immediately preceding the meeting.

Jan 9, 1916

By Gustaf Ising

For relative gravity measurements, the author in 1918 described an instrument1 of which the essential part consists of a highly astatized, standing pendulum turning about a horizontal elastic axis. This type of instrument has been used recently in practical field work, therefore a description of its principle and technical development is given herein. Part I, describing the principle, is a direct translation of the original Swedish paper.1 Part II gives an account of the practical elaboration of the instrument, together with some description of measure-ments performed.

Jan 1, 1937

Before hostilities between the colonies and Great Britain began in 1775, most of the coal used in the northern colonies undoubtedly came from England, with some supplies for New England coming from Nova Scotia; in New York and Philadelphia the supply came from England with some from the Virginia mines. Table 4 shows data obtained from the Public Records Office, London, for the years 1768-1772. This table supplements Table 3, which records only a few shipments from Richmond in 1768 and 1769; as there was no coal shown in imports coastwise in 1769 in Table 4, and only two small shipments in 1769 in Table 3, there may have been a cessation of shipments then, for some reason not now known. In Table 5 are incorporated all the data in the first two, with a few earlier years, and an attempt is made to estimate the amount used during the period by allowing for coal exported. With the small total tonnages a carryover from one year to another makes a large difference in the annual figures, but over the period the result may be fairly indicative of the amount of coal used before the Revolution. According to present day ideas the quantity of coal used during that war was very small, but apparently it was badly needed for the manufacture of the small amount of munitions made in those troublous days. As Philadelphia was the leading city along the Atlantic coast, and as the southeastern part of Pennsylvania was the leader in making iron, as well as making rifles, it is natural that the first call for coal came from there. At first, procuring supplies such as coal, powder and sulphur was handled by a Committee of Safety, which later became a Council of Safety and later this committee's functions were turned over to a Board of War, functioning with the military organization of the colony. . The organizations of the several colonies were slightly different, but Pennsylvania, Maryland and Virginia followed this scheme generally. Later in the war the Congress began to make arms for the troops, and it is difficult now, with the few records available, to tell when the state functions ceased and those of Congress began. On December 5th, 1775, the Committee of Safety

Jan 1, 1942

By completing a double-track railroad cut-off, involving a large volume of cut and fill, in addition to a half-mile bridge spanning an important French river, engineers in the zone of the Services of Supply have opened up a route by means of which hours of valuable time are being saved in transporting men and materials to combat areas. Its most valuable feature is that it provides a means for by-passing a certain city where several, French railroad lines converge and where, consequently, congestion of traffic has been responsible for delayed train movements. To avoid a double-track turnout, which would have involved a cross-over cutting one of the French tracks, the two track connections of the cut-off are taken off from opposite sides of the French right-of-way. This involved running one of the new lines of the cut-off out from the main line track on a fill to a point where it could be brought back and over the French track on a steel girder bridge. Beyond this bridge the two tracks of the cut-off converge and straighten out in the standard type of double-track construction. The new cut-off is about 5 3/4 mi. (9 km.) long and has required 160,000 cu. yd. of cut (122,329 cu. m.) and 414,000 cu. yd. (316,527 cu. m.) of fill. In the biggest continuous fill a-yardage of 180,000 has been placed; the road-bed in this section-being-about 40-ft. (12 m.) above the original ground surface. The bridge portion of the cut-off, 2190 ft. (667.5 in.) long, is made up of ninety-nine 14-ft. (4.3 m.) timber spans and sixteen 50-ft. (15.3 m.) steel girder spans. This is the longest bridge which engineers of the American Expeditionary Forces have built in France. The timber spans are supported by pile trestle bents, while the longer steel girders rest on clusters of 43 piles. Two pile drivers of the steam-hammer type worked from each -end of the bridge toward the center of the river, while a drop hammer worked westward from the shore end. In this structure nearly two thousand piles 50 ft. or so in length had to be driven.

Jan 12, 1918

By H. G. Doll

A new electrical logging method is described which measures the resistivity of small volumes of material near and behind the wall of the bore holes. The very small electrode systems used are supported in the face of the flexible insulator pad of appropriate dimension maintained in contact with the wall. The measurements are recorded simultaneously with two different electrode spacings. This method provides a very detailed record of the formations and particularly of the permeable beds traversed by the bore holes. The application of MicroLog to the location of permeable zones within compact formaltions, such as limestone, and to the determination of the amount of sand existing in sequences of thin shale and sand streaks is discussed. The possibility of quantitative determination, providing a step toward the evaluation of formation porosity and mud cake thickness, is also examined. Field examples illustrate the essential features of the method. INTRODUCTION In conventional electrical logging, the spontaneous potential (SP) log is used to delineate the permeable beds, and the resistivity logs are used primarily to provide indications concerning the fluid content of the beds. When the formations are much more resistive than the mud, as happens, for example, in limestone fields, the SP currents are short-circuited by the more conductive mud column, with the result that the SP log is quite rounded. In that case, the SP log generally gives the approximate location of the permeable formations but it cannot be used for an accurate determination of the boundaries of each permeable bed.' Solutions for the problem of obtaining a better determination of the permeable beds in limestone fields were developed from two angles. One approach consisted in improvements to the logging of the SP, as given by Selective SP logging and Static SP logging. These new methods, which have been described in an earlier paper,' give good results when the mud is not too salty, but they are still in a somewhat experimental stage, mostly because the development efforts have lately been concentrated on another approach to the problem, i.e., the MicroLog.

Jan 1, 1950

Jan 1, 1934

By E. V. Given

Designing a tailing dam is a major step toward fully integrated mill operation. In the case of large concentrators considerable planning is necessary, and the site of the tailing disposal area may very well dictate the location of the concentrator itself. Before a suitable location can be selected several pertinent factors should be investigated: estimated life expectancy of the mine and, if possible, approximate total tonnage; knowledge of daily mill capacity; and the possibility of future mill expansion. In addition, the area should be able to store tailing for many years and, from a cost and maintenance stand- point, gravity flow will probably be desired.

Jan 7, 1959

By Dennis V. D’Andrea, Larry R. Fletcher, Peter G. Chamberlain

The evaluation of potential in situ copper leaching deposits requires a thorough examination of the geologic, mineralogic, hydrologic and physiological characteristics of the ore body. The decision to develop the deposit is made with these data along with leaching properties, estimated copper recovery, and economic analysis. A test blast followed by pilot leaching can a so be used for further evaluation and to reduce uncertainty regarding the deposit's potential. This report describes a number of ground characterization techniques that can be used to evaluate potential deposits. Field methods include geologic mapping, groundwater hydrology, core drilling, geophysical logs, permeability testing, and in-situ stress measurements while laboratory tests include assaying, mineralogy, leaching, rock physical properties, size analysis, and computer simulation.

Jan 1, 1980

By William F. Haddon, Phillip J. Maddex

Marco Polo brought the first borax to Europe late in the 13th century. It was especially treasured then for one of its many qualities-that of working with gold as a soldering flux. Georgius Agricola in 1556 gave it the name chrysocolla (which the Moors called borax)-literally, "gold glue." Deposits of borax have been elusive and widely scattered-first found only in Tibet and Italy, and, in 1836, at Iquiqui, Chile. Dr. John Veatch made the first California discovery in 1856 while examining a mineral spring east of Red Bluff. This "Borax Lake" soon supplied 90% of U.S. demand, but flooding and other production problems caused the scene to shift from Borax Lake to Little Borax Lake and then to Nevada in 1871. Early transportation was by "Twenty-Mule Teams."

Jan 1, 1971

By Wilbur T. Stuart

THE increased demand for iron ore has necessitated a re-examination of ore-bearing lands on which the presence of water previously has indicated hazardous and expensive operating conditions. In view of the importance of iron ore production to the national economy and defense, the Ground Water Branch of the U. S. Geological Survey, in cooperation with the state of Michigan, began a study of mine drainage in the Iron River district in 1945, and later extended the work to the Marquette district. The purpose of these studies was to define the principles involved in the movement of surface and ground water toward the mined areas, with the hope that the information obtained in the research would lead to the development of methods of water control and to a reduction in the total mining costs.

Jan 12, 1951

By W. N. Lacey, D. F. Botkin, B. H. Sage

JOULE-THOMSON coefficients for two natural gases were determined at pressures up to 600 lb. per sq. in. throughout the temperature interval between 70° and 310°F. From these primary data and available information relating to the isobaric heat capacities of the components at infinite volume, the heat capacities of these gases were computed throughout the above-mentioned range of pressures and temperatures. The enthalpies of the gases were computed as a function of state and the results compared with values obtained by several methods of prediction currently available. The results are presented in graphical and tabular form.

Jan 1, 1942

By Walter E. Heinrichs

Since World War II exploration geophysics has derived its scope from the following factors: first, the usual post-war interest in exploration to rebuild war-depleted reserves; second, the impetus supplied by the uranium prospecting boom; third, increased demand for natural resources due to the Korean War; fourth, the discovery of substantial metallic ore by geophysical means in Canada, the U. S., and other countries; and, finally, continuing discoveries of commercial oil by geophysical methods throughout the world. The past year's national business slump has severely curtailed mining exploration in general and correspondingly has brought about even greater reductions in applied geophysics in mining. Petroleum exploration, conceived and executed on a broader statistical basis than mining, has kept up its geophysical programs relatively well, although domestic work has been substantially reduced.

Jan 7, 1959

By John T. Schamaun

Recent applications of explosives and blasting agents to rubble rock have led to requirements for more elaborate design and analysis methods. In most blasting uses, it is necessary not only to fracture the rock, but also to move the broken rubble in a predictable manner. Many in situ extraction techniques require rubblization to take place in a confined region where rock motion is a predominate factor in creating a permeable broken bed. In this paper, two analytical methods are presented which describe the large rubble motion during blasting. These methods provide the blast designer with a tool for evaluation and further refinement of blasting patterns and timing sequences. In both these methods, the rock medium is represented by a series of discrete, discontinuous regions. The use of discontinuous techniques rather than the classical continuum methods, results in better approximations to the rubble motion. These regions are set in motion by pressure loads from the explosive. The motion of these regions is then calculated numerically using interaction laws between regions in contact. The basis for these models or methods is presented along with the background for selecting explosive pressure loads and rock mass material behavior. Typical examples, including both cratering and bench blasting geometries, are discussed which illustrate the use of these models to predict rubble motion. Such engineering representations appear to provide a practical method for use in predicting rubble motion and a tool for design evaluation of blasting in confined geometries.

Jan 1, 1984

In accordance with the usual custom, manuscripts to be presented at the next meeting of the Institute must be in the hands of the, Secretary before July 1, 1917. Manuscripts to be properly distributed in advance of the meeting must be in the hands of the Secretary before June 1, 1917. At the last meeting of the Institute 45 papers were presented, and 42 of them were actively discussed. This experience makes us believe that advance distribution is the best possible means of getting a good discussion of papers and of securing for them the interest of the members of the profession. It will be impossible, however, to give the papers proper distribution if they bare not received before June 1, 1917.

Jan 4, 1917