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By George H. Cook

(Read at the Wilkes-Barre Meeting, May, 1877.) AT first sight this subject seems to belong to pure theoretical geology, but examination will soon show that it has important practical and economic interest to the mining engineer. The conclusion that all the northern portions of our country, as well as of the eastern continent, have, in the later periods of geological history, been covered with a thick bed of ice, is now accepted by geologists. This bed of ice, except in its greater magnitude, was like the modern glaciers of the Alps, and other mountains which extend above the line of perpetual snow. The marks it has left upon the surface show that it was comparatively thin on its southern. edge, but that its thick¬ness was much greater a little further north, and that it was several thousand feet thick at its heaviest parts. This variation of its surface would give it a descending slope towards the south, and cause the mass of ice, like a semifluid substance, to move in that direction.

Jan 1, 1878

By James A. L. White

Of the natural elemental surfur deposits of the world, volcanic deposits are not only the most spectacular, but probably the most widely distributed. As defined for the purposes of this paper, volcanic sulfur deposits include those associated with all phases of volcanic activity, including eruptive flows, and fumarolic and hot spring deposits. The line of demarcation between the latter and sedimentary deposits is not always clearly defined. Although volcanic sulfur has played an important role for centuries, serving as essentially the only source of sulfur, currently it is considered as purely marginal material. Volcanic deposits were relegated to this position by the advent of Frasch sulfur into world markets, which established sulfur prices and annual production levels with which volcanic sulfur cannot compete, Since early in the 20th century commercial interest in volcanic deposits of sulfur has been high only when premium markets are available. This occurred in the early 1950s and is the case at present. Considerable effort is currently being expended to establish new producers of volcanic sulfur, and to expand current operations or reactivate previous ones.

Jan 6, 1968

By Karl Cohen

The question of attainment of competitive nuclear electric power is of interest to uranium producers because the rate of attainment of this goal determines the date when there will be a solid, non-political, domestic uranium market. It is a burning question to those of us in the civilian nuclear power business, because our entire business future hinges on how well, and how soon, we can make electricity from nuclear reactions at prices comparable to electricity from coal. For an idea of the magnitudes involved, consider that the first fuel load of the Dresden (Illinois) nuclear power station, plus spares, will be about 90 tons of 1.5 pct UO2. This requires about two-and- a-half times as much natural uranium oxide feed to the diffusion plant, or 225 tons. This, in turn, represents about a month's production from the nearby Uranium Reduction Co. mill. Note also that the 180,000 kw electric output of the Dresden station will be about 0.1 pct of the national electric generating capacity in 1960.

Jan 12, 1958

By J. M. Lohr

THE characteristics and uses of thermocouples of platinum and the platinum alloys being so well known, this paper will be confined to base-metal couples. During the past decade, there has developed a strong demand for thermocouples made of metals cheaper than the platinum alloys, and suitable for industrial heat measurements. Much research has been clone but only a very limited number of alloys have been found to possess the necessary characteristics for general technical use. In the development of thermocouple alloys it is necessary to consider the following points: The electromotive force and temperature relations; permanency or constancy; reproducibility; manufacturing difficulties; durability; and accuracy in use. The electromotive force developed by the thermocouple should increase with the rise of temperature according to some definite law. It is desirable that the electromotive force should vary directly with the temperature difference of its junctions, in other words, giving a curve linear or nearly so. It is also desirable that the resulting electromotive force be as large as possible for any given range of temperature, thereby insuring greater accuracy of readings.

Jan 9, 1919

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 7, 1917

By Donald E. Scheck, Da-Rong Chou

The application of geostatistics to coal reserve analysis is discussed. One problem in particular, the selection of the optimum locations for exploratory drill holes, is considered in detail. A new interactive program to help the geologist determine the best locations is described and applied to a specific property. The steps in the process are described and then illustrated using a mine's actual data. First, a variogram is selected based on graphical displayed information from the known sample data. Kriging estimates are made for the region of interest and the blocks within the region. The location of future exploratory drill holes is selected based on the criterion of minimizing the region estimation variance for a given number of exploratory holes. The least number of exploratory holes required to meet a specified upper limit on the regional variance is also determined. The computer generated recommendations for the exploratory drill holes are compared to a manually prepared drilling plan. The post- drilling analysis of the results is compared to the predicted values.

Jan 1, 1983

By Charles E. Packard

Many coal producers have been faced recently with the problem of arranging their production facilities to accommodate recent trends in the transportation of their product. Each operator is normally faced with a different problem requiring a system to meet his specific needs. It may be that he would be required to load a seven or eight thousand ton integral train each day which would naturally call for a large storage pile, high loading rate, accomplished in a minimum of time On the other hand, it may be that he is faced with furnishing coal to make up one-half of a unit train that is to be assembled twice a week. Whether the problem is large or small, many considerations must be given to each specific problem to be certain that the proper scheme is applied. The operator actually has several choices as to what type of storage and loading facilities he may consider. The storage pile, for instance, may be open type, conical in shape, kidney-shaped, or long and wedge-shaped. It may also be enclosed by steel or concrete

Jan 8, 1964

The following rules, upon approval by the Board of Directors, shall serve as guides in the practical applications of the Bylaws for the operation of the Institute and have the full power and effect of Bylaws, however, these rules may be changed, modified, re¬pealed or amended when deemed necessary by the Board of Directors Any change or alteration of these Rules shall be published in the Journals of the Institute within three months after such alteration is adopted ARTICLE I-ORGANIZATIONS OF THE INSTITUTE Section 1-Societies Rule 1-Governing Body Each Society shall form its own governing body composed of an Executive Committee, or similarly designated executive body, duly elected officers, and a Nominating Committee for the nomination of Institute officers as provided by the Bylaws of AIME and of each Society approved by the Board In all correspondence and printed matter the Society Boards of Directors shall be specifically identified For ex¬ample, the Mining Board of Directors or the Board of Directors of the Society of Mining Engineers Using simply the "Board of Directors" could cause confusion

Jan 1, 1960

I HAVE already described to you many kinds of fusions and fires and still have many to describe if1 am to guide you, as I intend, among the operations of these processes. In all these, quantities of charcoal and various kinds of it must be handled continually and it therefore seems to me necessary to tell something about charcoal for aiding you in these processes. Without it artificers could scarcely bring their works to an end, because it is the food that nourishes the fire both for smelting and for softening the metals, or for calcining or drying things out. [61] It is a very powerful means and not only is its fire used for many more works than other fires, but it is also essential. Although there are many other things that make fire and would make it, I do not know of any that are better adapted for this purpose, or that can be more easily procured in large quantities, than wood and charcoal. For, as you can see, very great forests are found which make one think

Jan 1, 1942

By D. N. Sutherland

The cassiterite flotation circuit at the Renison concentrator has operated with increasing levels of automatic control since late 1981. The circuit operates at high levels of recycle which make it difficult to control manually so that the initial control strategy was to stabilize the mass flows around the circuit prior to circuit optimization. Control of the air supplies to the flotation banks was introduced to achieve this stabilization and initial results indicated that some success has been achieved, as indicated by improvements in the overall circuit performance and reduction in the stream variabilities. These improvements were gained through control of the major recycle to the roughing stage which dominates the circuit behaviour. Feed-forward control of collector addition has also been introduced successfully, but attempts to control the final concentrate grade have been less satisfactory. This work is continuing and the objective of current activity is to include the three cleaning stages in an overall circuit control scheme as a first phase of metallurgical optimization of the operation.

Jan 1, 1984

By T. A. Rickard

The lodes of Cripple Creek, Colo., partake of the composition of the geological formation which they traverse. The prevailing rocks are andesitic breccia, lying upon granite, and also bodies of phonolite, trachytic phonolite, nepheline-basalt, etc., penetrating both the granite and the breccia. At Kalgoorlie, in West Australia, the prevailing rock is schistose, and has not been certainly identified, though microscopic sections indicate the probability that it was originally an acid eruptive. The lodes are essentially bands, more highly schistose than the encasing rock, and impregnated to a notable degree with disseminated pyrites and secondary calcite. During 1899 Cripple Creek produced 425,590 tons of ore, having a gross value of $15,658,254; during the same period the output of Kalgoorlie was 467,048 tons, valued at $17,724,587. In chemical composition, the ores at Cripple Creek and Kalgoorlie, respectively, present differences equally interesting to the petrographer and the metallurgist. In both cases we have to deal with altered eruptives as the matrix of the ore; but the much older rock of Kalgoorlie has undergone more decompo-

Jan 1, 1901

By Thomas W. Yardley

In many years' experience as a maker and purchaser of cast-iron coated pipe, I have never met with any standard form of specifications for such. Each water-works company, employing a hydraulic engineer, has, under his direction, prepared complete specifications for the particular conditions required; but I cannot find that any two are alike; and each foundry, in bidding for the supply of such pipe, makes the price to cover the conditions' required. I, therefore, have the honor of offering to the Institute a form of specifications for cast-iron coated water-pipe, that may be found useful to water-works companies and others requiring pipe of this kind. The conditions are all reasonable, and can be carried out by makers without additional cost, and with advantage to the purchaser. Section 1 gives the kind of pipe, with its general characteristics. Section 2 specifies that neutral pig-iron shall be used, since such iron possesses the strength required, and is uniform in its shrinkage. Section 5, requiring makers to give the brands of pig-iron used

Jan 1, 1890

By Robert Steinitz

SOFT iron parts for magnetic applications, particularly pole shoes, constitute a major portion of the ferrous products of powder metallurgy. The residual pores in pressed and sintered parts reduce values such as the magnetic permeability but service experience extended over a number [ ] of years has proven beyond doubt that in many instances the lower density of powder parts is not prohibitive to their use m replacement of machined magnetic parts The. magnetic requirements for pole shoes particularly the permeability, vary within wide limits, especially with the relative size of the air gap in the finished assembly. The overall permeability of an assembly, µ, is given by the formula [ ] where µm is the permeability of the core material, l the total length of the magnetic path, and a the length of the air gap. Fig 1 shows the variation of the overall permeability with the permeability of the core material, calculated according to Eq I for an air gap of 1 pct of the total length of the magnetic circuit. It is readily recognized that to use core materials hav-

Jan 1, 1948

By Donald W. Gentry, John F. Abel

This paper presents some of the results of a rock mechanics instrumentation program designed for, and implemented at, longwall panel 4N at the York Canyon Mine near Raton, New Mexico. The objective of this particular instrumentation program was to determine the response of the rock mass to longwall mining of a thick coal seam utilizing shield-type supports. Measurements were made in the rock along the ground surface, above the coal seam, in the coal seam, and immediately below the coal seam. Longwall test panel 4N had a total developed length of 762 m (2500 ft) and a face width of 168 m (550 ft), Fig. 1. The seam mining height in the panel area was approximately 3 m (10 ft). The average depth of overburden above the panel is 107 m (350 ft) although it ranges from 73-134 m (240-440 ft). Roof support at the face was provided by 116 Hemscheidt 320 HSL shields. These shield-type supports weigh 11.4 metric tons each.

Jan 3, 1978

By David J. Mack, Chin Bea Kim

The decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was studied by isothermal transformation. Its progress was followed by metallographic, hardness, and X-ray diffraction methods. Three transformation products were found: lamellar pearlite at high temperatures; an intermediate temperature structure; and martensite at the lower temperaCures. No transition structu,ves were found. THE decomposition of the Ni-Zn eutectoid at 56 wt pct Zn was stuadied as part of a long-range program of study on the eutectoid transformation in alloy systems which do not have one or more components which exhibit allotropy. Available information on the Ni-Zn eutectoid transformation is limited to that presented in connection with the determination of the phase dilagram. No systematic studies of the eutectoid were found in the literature, alkhough the microstructures of the Ni-Zn eutectoid were reported by Tamuru.3 X-ray diffraction data exist for the ß, ß1, y , and y1 phases.' EXPERIMENTAL PROCEDURE The eutectoid alloy was prepared from "A" nickel shot and Bunker Hill super-purity zinc (99.998 pct).

Jan 1, 1962

By Robert A. Melton

Since many of the easily mined, continuous, thick coal seams in the Appalachian Region have been exhausted, new exploration and mining is being directed toward less continuous seams that are under more cover and are more difficult to mine. The direct results of this are that more money and time and more expertise and data are needed to plan and open new coal mines today. It is also becoming apparent that the old methods of assimilating and preparing information needed for mine planning are inadequate to meet the needs of today's modern mining engineer, especially in the areas of data gathering, storage, retrieval, preparation, and interpretation. The system described here allows assimilation of old and new core data in a relatively quick, accurate, and efficient manner. The system is a set of computer assisted procedures consisting of the following four basic steps: 1) raw data collection, computer input, storage, and graphic preparation, 2) geologic profile correlation and establishment of seam continuity, 3) computerized data posting of important seam parameters, 4) geologic and planimetric analysis for mine planning.

Jan 1, 1977

By H. M. Howe

The chief purpose of this note is to call attention to the triaxial diagram as a convenient means of illustrating the properties of slags, and by this example of its use to commend it to those inclined to graphical studies having other possible applications. Explanation.—In the common or di-axial diagram, the properties corresponding to any point are determined by its perpendicular distance from each of two axes. For example, in an ordinary stress-strain diagram the properties of a given point in the curve are, first, a stress cd so many pounds per square inch, because its perpendicular distance from the horizontal axis of the diagram corresponds by the vertical scale to that stress; and second, a strain or elongation of so many per cent., because its perpendicular distance from the vertical axis corresponds by the horizontal scale to that elongation. It happens that, as a matter of convenience, we habitually place these two axes at right angles to each other; so that our measurenieilts happen to be made not only at right-angles to

Jan 1, 1899

By R. R. Nash, W. F. Sheely

Experiments were conducted on magnesium monocrystals in order to collect quantitative information on the mechanisms which limit the rate of basal slip. Using critical shear stress and creep data, activation energies for creep at low aid at high temperatures were derived. The activation energy at low temperatures is the same as that for jog formation and the activation energy at high temperatures agrees with that for climb. COTTRELL has suggested that at low temperatures, the expansion of dislocation loops under stresses near the yield strength is limited by the rate at____ which the expanding loops can cut the "forest" of dislocations passing through the glide planes.' On the basis of this mechanism, seeger2 has derived expressions for low-temperature creep and for the relation of flow stress of single crystals to temperature. In the work reported here, the authors have performed experiments designed to obtain quantitative data on the physical properties of the dislocation intersection mechanisms operating during basal slip in pure magnesium monocrystals. Above a critical temperature, dislocations thread-

Jan 1, 1961

By Kazutami Imai

Effects of heavy metal ions on the growth and the activities of iron and sulfur oxidation of Thiobacillus ferrooxidans were investigated. Mercuric, silver, and stannous ions inhibited both of the growth and the iron- oxidizing enzyme system of the bacterium. On the other hand, uranyl ion inhibited the growth, but it gave almost no effect on the iron-oxidizing enzyme system. The inhibitory effect of uranyl sulfate on the growth of the bacterium is intensified on lowering the cultivating ' temperature from 28 ºC to 7 ºC. In the concentration of 10-3M, cadmium and copper ions inhibited colloidal sulfur-oxidizing activity of the cells 69 and 52 %, respectively, though they did not inhibit the iron-oxidizing activity at all in the concentration. On the contrary, stannous chloride did not givr any effect on the sulfur-oxidizing activity of the cells, though it inhibited the iron-oxidizing activity 55 % in the concentration of 10-3M. Several differences were observed among the cytochrome systems of cell-free extracts of the cells grown on iron and on sulfur.

Jan 1, 1976

By J. G. Bradley

On February 1, 1971, United States Steel Corporation, Lorain Works began operation of its first BOP facility equipped with a partial combustion gas cleaning system.- This shop consists of two 220 ton vessels. Figure I schematically describes this partial combustion gas cleaning system and highlights the necessary features for it-s safe and efficient operation. Waste gases are drawn into the membrane hood by a 2250 H.P. induced draft fan and are first quenched by the six inch bull nozzle at the top of the hood. Larger solid particles are separated from the gas in the quencher venturi and final scrubbing takes place in the P-A high energy venturi scrubber before the cleaned waste gas is burned in the flare stack. Scrubbing water is routed through a cyclone separator and then cycled into one of two 100' diameter thickeners. Underflow sludge which averages 20% solids is dewatered by 100 H.P. centrifuges. The clear overflow from the thickeners is recycled first to the P-A venturi and then to the quencher before returning to the thickeners.

Jan 1, 1972