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By Gerald Laswell

Jan 1, 1976

By John Birkinbine

The iron industry of the United States, and, in fact, of the world, was established with charcoal as fuel. Long before the value of mineral coal was recognized, the carbonization of wood was carried on in connection with various metallurgical processes, but at the present time we look upon establishments using charcoal as the remnant of a former greatness, and are apt to sympathize with the operators because they have no other fuel to depend upon. In the iron

Jan 1, 1883

By R. H. Swallow, George Hess

C. G. BALL*—These maps are obvi-~,usly quite helpful in many types of mining engineering, but I want to find out if the prints which you obtain in the first step toward making any aerial contour map have already been corrected for tilt. Is that done afterwards only if you are going into the process of making a contour map ? GEORGE HESS (authors' reply)— The tilt correction is the first step in either compiling the mosaic or compiling the total map. They must be corrected. C. G. BALL—But are the contact prints themselves corrected for tilt? GEORGE HESS—They are not corrected. E. R. KAISER†—I enjoyed this paper very much, and am glad to learn that the methods have a high degree of accuracy and are in use in the coal industry. Accuracy in dimensions is understandable from the paper. Would you tell us how accuracy can be obtained in the vertical dimensions by means of the photographs so as to permit drawing contour lines? GEORGE HESS—To explain our process, even in a limited way, is quite a large order. However, the basic principle involved is the measurement of parallax by viewing two overlapping photographs stereoscopically. It would almost be necessary to have the various instruments here on view to adequately explain their operation. E. R. KAISER—Are the elevations for reference obtained at more than four points ? GEORGE HESS—The pattern of control is four points obtained in the corners. Primarily. that is to restitute the picture and horizontalize it. The vertical control points are read ill on the stereometer and a direct comparison is made while draw- ing the contour lines. You do have to have those four points. But one stereoscopic pair of 5 ft contours has some 340 acres on it, consequently for every four points picked up 340 acres are contoured. E. R. KAISER—How does your method compare with that used by the military reconnaissance during World War II? GEORGE HESS—The Army did not get into this refined mapping. Most of their work has been reconnaissance mapping by taking one vertical and two oblique views. Basically, the same principle is used. Our maps are for engineering purposes. The Army was primarily interested in reconnaissance. E. R. KAISER—You could take more than 48 pictures in one flight? GEORGE HESS—Yes, the Brock camera accomodates 48 pictures per magazine. We are limited by the hours of greatest light, though, 2 hr before high noon, and 2 hr after high noon. Shadows do affect the picture. The shadows can-

Jan 1, 1950

By Nev A. Gokcen

PUBLISHED data on the solubility of nitrogen in liquid manganese are widely discordant. Ochsenfeldl observed that a Mn-N alloy with 3.6 pct N consisted of solid and liquid phases at 1260°C but at 13 00° to 1340°C the solid phase disappeared and the liquid contained 0.1 to 0.13 pct N. In contrast Saito's measurements at approxhately 1400°C yielded an average value of 0.97 pct N. Sieverts3 volumetric method is not suitable for the determination of gas solubility in manganese because the liquid metal vaporizes readily and condenses in the cooler parts of the apparatus where it can absorb large amounts of nitrogen. The purpose of this investigation was, therefore, to determine the solubility of nitrogen in manganese accurately in the range of 1273" to 1500°C. The experimental method used in this study was as follows. Electrolytic manganese of 99.9 pct purity, and weighing 50 g, was melted in a pure alumina crucible placed in a tubular furnace. Temperature was measured with a Pt-10 pct Rh thermocouple and controlled within ± 5°C. Pure nitrogen was bubbled through the melt for 1 hr at constant temperature and then a sample was taken by sucking the metal into a 2-mm clear silica tube and immediately quenching in water. The sample was broken into small pieces and found to be sound to the naked eye. The entire sample was then dissolved and the resulting solution was analyzed for nitrogen by the well-known solution-distillation method. The experimental results are presented in Fig. 1. All the nitrogen solubility data refer to 1 atm of nitrogen pressure; hence the observed values are slightly corrected by using Sieverts' equation when the atmospheric pressure differed more than 5 mm Hg from 760 mm, and further, in the case of the runs at 1500°C the correction arising from the presence of Mn vapor has been made. (Cf. Eq. [3]). Scattering in the data is within ±5°C in temperature measurement and ±3 pct in total nitrogen analysis. The straight line in Fig. 1, correlating the percentage of dissolved nitrogen, %N, with the inverse temperature in OK-1, can be expressed by:

Jan 1, 1962

By Richard Dunmore

Tests of the MRDE firedamp prediction method have been carried out in a number of longwall districts with different conditions. The method itself and its development have been described previously At many test sites the prediction has been good, i.e. the calculated gas emission levels have agreed with measured values, averaged over a period of many weeks, within a few percent. In other cases, where there have been larger discrepancies between calculation and measurement, investigations have shown that these may be attributed to particular conditions of mining or geology. Recognition of these conditions in advance of mining is clearly desirable to improve the accuracy of the initial prediction. It has been shown that variations in gas emission rates depend largely on coal production in terms of the weekly advance of the coal face. Although there appears to be a random element present, variations in gas emission levels calculated from changing face advances agree well with measurement. The accuracy of prediction therefore depends on how well face advance can be forecast and needs to be updated as the working proceeds in the light of the face performance actually achieved. Continuous monitoring of the mine environment provides the information necessary to compare actual gas emission with predicted levels, and computerised systems make it possible to carry this out in real time. Predictions can thus be adjusted to take account of emission levels measured in previous weeks These adjustments, whether they are made after the first few weeks or subsequently during the district life, would also be used to alert management to particular abnormalities or significant changes in gas emission.

Jan 1, 1982

The difficulty of finding new ore bodies, the complexities of patenting them when they are found, and the absence of incentive legislation for exploration have limited mining exploration in the United States mostly to the big companies. This situation, coupled with ECA spending abroad, has caused American capital to look outside our national boundaries for investment opportunities which are further made attractive by some relaxing of restrictions to gain American dollars and patronage.

Jan 1, 1950

By F. W. Gordon

Since the waste gases of the blast-furnace came to be generally utilized in heating the blast and raising steam, the gradual improvement in the economy of fuel, mainly through the nse of higher temperature in the blast, has impoverished the gases. The increased output per unit of measurement of the furnace, and the increased height of the furnace, have markedly increased the resistance to the blast, thus enormously increasing the duty required from the gases. In other words, a gas reduced in heating power by a further dilution of CO, is required to raise the temperature of the blast to 1800' Fahr., where formerly 600' was a good temperature, and at the same time to raise steam enough to drive the air into the furnace at a pressure of from four to eight pounds in coke practice, and from eight to twelve pounds in anthracite practice, and also pump at least double the water formerly used at furnaces. Hence the necessity for the employment of the best scheme for thoroughly consuming these gases with the least dilution of air, and the use of the best device for absorbing the heat prodnced for the purposes above mentioned. In a former paper before this Society the writer called attention to such improvements as had been made by his firm, by which it was claimed 1400' Fahr. could be maintained in the blast by a less consumption of gas than was required to maintain 900' when using pipe-ovens; and it would not be too much to say that 1600' Fahr. might now be written in place of the 1-400. The object of this paper is to give the practice of our firm in the

Jan 1, 1884

By Karl J. Benecke

Though the first patent on a bucket wheel excavator (BWE) was granted in 1881 in the US, this technology was developed in Germany to the high standards of today. However, this development was only possible in parallel with development of shiftable belt conveyors and boom stackers. The combination of these three types of equipment in the open pits of the Federal Republic of Germany has made lignite the cheapest energy source for power generation, despite the low heating value of German lignite on the order of 8500 kJ/kg (3600 Btu/lb) only. Comparing the costs for fuels used in power generating on the basis of their heating value, the relation between lignite, high quality black coal, and imported crude oil is on the order of 1 to 1.5 to 2.5, hence highly in favour of lignite.

Jan 8, 1979

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Jan 1, 1938

By E. Mcl. Tittmann

Deep-seated human instincts urge us to positively mark the passage of time. We celebrate the passage of each year. Years give way to decades, and decades to half centuries and centuries. At all these mileposts we are inclined to pause, take a look around and catch our breaths before embarking on the next leg. We are at such a point now and this meeting I am sure will give direction to the road ahead into the decade of the seventies. In looking around at this point, 1979, it is obvious to all of us that the environment in which we must mine, mill, smelt and refine lead and zinc has radically changed. These changes have, of course, occurred over a long period of time. They have, however, all been in the same general direction. They have all had the same motivation. The period of greatest contrast is probably the fifteen years just before World War II and the fifteen years following the end of that war. I thought that I might review briefly with you what seems to me to be four of the more important changes that have developed since World War II that profoundly affect our activities in the lead and zinc industry. I mentioned before that all these changes have been in the same direction; that is, they have all tended to restrict our freedom of action in pursuing our objective of producing lead and zinc on a competitive basis at a profit. Consequently, in discussing them you may think that I am merely viewing with alarm. This is not the intent. This is merely supposed to be an objective analysis. I think it appropriate before discussing these trends in detail to examine the position of lead and zinc today.

Jan 1, 1970

By Donald P. Richards, John F. Abel

Geotechnical site investigation for new mine shafts can reduce the level of design uncertainty for shaft linings. The parameters which determine the lining strength required include rock strength and hydrologic properties, the in situ stress conditions, and the concrete strength. These parameters are applied to analytical methods of shaft lining design using the plastic and clastic assumptions of rock response to determine the required lining thickness to maintain the stability of the shaft excavation.

Jan 1, 1982

By D. H. Yardley

Diversion of the American Falls of Niagara to permit investigation of ways and means to stabilize the falls while retaining or improving its natrual attractiveness is the geoengineering work that has received greatest public attention this year. The falls are re- treating slowly as rock falls occur while talus de- posits at the base have increased in size. One of the noteworthy questions is whether the talus should be removed-i.e. is it providing support to the base, and so what will happen if it is removed? Certainly the appearance would be improved if the talus were taken away. Geoengineering studies involve mapping of joints, stress measurements, core work and rock sampling and testing, Present work will provide data and interpretation for design of a long term stabilization system, Once basic information is obtained, water will be returned to the normal channel until such time as the detailed design is decided upon. The falls will then be diverted a second time while necessary work is performed. A number of site-environmental studies were carried out for the location of nuclear power plants. These projects involve geology, foundation engineering, hydrology, seismology, meteorlogy, marine geology (in some cases), rock mechanics and occasionally blast monitoring. In one case (investigated by Dames & Moore) the site area was underlain by caverns in limestones at shallow depths but with no surface expression. The geotechnical problems consisted of determining proper spacing of drill holes to locate caverns. Spacing was dependent on the smallest size of cavity that could constitute a support-stability problem for the plant. The finite element method of analysis was used to determine stress conditions around cavities of various size and depths, to assist in determining critical parameters.

Jan 1, 1970

PRESIDENT OF THE COUNCIL ROBERT W. HUNT CHICAGO, ILL. (Term expires February, 1907 ) VICE-PRESIDENTS OF THE COUNCIL WILLIAM P. BLAKE TUCSON, ARIL. THOMAS F COLE DULUTH, MINN. IRVING A. STEARNS WLKES-BARRE, PA. (Term expires February, 1907 ) HENRY M HOWE NEW YORK, N. Y. J. B GRANT DENVER, COLO. JAMES D HAGUE NEW YORK, N. Y. (Term expires February, 1909 )

Jan 1, 1910

By Gregg A. Scott

Upper Stillwater Dam is to be a roller-compacted concrete gravity structure, founded on nearly horizontally bedded sandstone and argillite rock. An overview of the testing and analyses used to evaluate the adequacy of the foundation relative to deformation, seepage, and stability is presented.

Jan 1, 1984

By Darrel W. Hansen

Morrow Point Dam and Power Plant are principal features of the Bureau of Reclamation's Curecanti Unit of the Colorado River Storage Project. They are under construction on the Gunnison River 20 miles east of Montrose, Colo. Johnson-MK is the prime contractor, and represents a joint venture of Al Johnson Construction Co., Minneapolis, Minn., and Morrison-Knudsen Co., Inc., Boise, Idaho. The power plant will be housed in an underground chamber in the left abutment, approximately 250 ft behind the original canyon wall. The chamber is 206 ft long and 57 ft wide. The distance from the foundation to the spring line of the roof arch varies from 51 ft in the service bay to 120 ft in the control bay. The roof arch has a rise of 16 ft. The longitudinal center line of the chamber is orientated east-west with the draft tubes discharging nearly due north. Access to the power plant chamber was possible through the cable tunnel, access tunnel, two draft tube tunnels, two penstock tunnels, exploratory tunnel, which became the ventilation tunnel, or the grouting and drainage tunnel leading to the dam. (See Fig. 1.) The shortest and fastest access was through the cable and access tunnels, and the contractor drove these two tunnels simultaneously. The cable tunnel and cable gallery excavation exposed a transverse section, at the west end of the chamber, that was 15 ft wide and extended from the crown to 5 ft below spring line. It was here that arch excavation began. The first 34 ft of advance along the arch was driven on three headings, and the muck was removed through the cable tunnel. Meanwhile, the access tunnel was completed, and a raise was driven from its crown to intersect the advancing arch excavation near the longitudinal centerline

Jan 1, 1968

By A. H. Taitt

The original basis for the search for oil in Great Britain was described last year.t During 1937 the exploratory drilling by the D'Arcy Exploration Company, Ltd. has been continued. Three wells have been completed in the south of England and a fourth is nearing completion. In addition, test wells are now being drilled in Scotland and East Yorkshire. Southern England The test well on the Portsdown structure, which at the end of 1936 was drilling in the Lower Lias at 5792 ft., entered the Triassic at 6540 ft. and was completed in that formation at a depth of 6556 ft., without encountering further indications of petroleum. The Henfield well encountered the Lias at a depth of approximately 4090 ft., and after drilling 800 ft. of an argillaceous development of that formation entered a series of marls, breccias and conglomeratic limestones of the Carboniferous. Drilling was suspended at a depth of 5105 ft., in the latter formation. The consistently impermeable nature of the strata encountered in the Portsdown and Henfield test wells focused attention on the desirability of obtaining shore-line conditions of the Jurassic. With this end in view the Kingsclere anticline, a few miles south of Newbury in Berkshire, was selected for a next test. The Kingsclere well has now reached a depth of 5032 ft. in the Lower Lias and has encountered a full development of the Jurassic. With the exception of the Portland sand, which has a slightly greater porosity, and the Corallian, in which relatively great thicknesses of impervious limestone were met, conditions of sedimentation have been found to be comparable with those of the earlier wells. Small traces of petroleum have been found in cuttings and cores, but formation tests carried out at frequent intervals have yielded no flow of oil. In order to test the Corallian, from which series an outcropping oil sand had been found, a test well was drilled in a near-by anticline at Poxwell in Dorset. The Poxwell well started in the Portland beds and entered the Corallian at 995 ft. The sands at the horizon of the out-

Jan 1, 1938

By C. M. Marquardt

Tramp iron and steel moving on a conveyor belt cause small currents to be generated in a coil situated in a strong magnetic field, which are converted to an alternating current and are amplified. The output voltage from the amplifier fires a thyratron with a relay in its anode circuit, which actuates a howler and simultaneously drops a spot of marker material on the belt.

Jan 6, 1950

By R. M. Stewart, C. W. MacQueen

Anaconda's Berkeley pit at Butte produces 34,000 tpd of ore averaging 0.8 pct copper. Two-and-one-half tons of waste is stripped per ton of ore, approximately 40,000 tpd by the company and an added 45,000 tons by the F&S Contracting Co. The company truck fleet consists of 24 Euclid and 18 Mack 34-ton, rear-dump diesel trucks.

Jan 7, 1961

By Noel Stearn

WHEN the Age of Machinery was suddenly thrust upon civilization about the beginning of the nineteenth century, an unprecedented demand for mineral resources sprang up. This demand brought about the rapid development of the known ore deposits and the discovery of such other deposits as could be encountered by energetic and canny pros-pectors. Thus in the countries now reasonably ac-cessible nearly all orebodies have been located except those which are totally concealed even from the eyes and "senses" of experienced and expert prospectors. The high rate of exhaustion of known ore deposits and the necessity of looking farther and farther ahead for raw materials as a matter of insurance on the stu-pendous capital outlays involved in mining, develop-ment, and conversion operations, have resulted in excep-tional activity in three different fields of effort. The first is purely geographic. Prospectors are now pene-trating the few hitherto inaccessible regions in the hope of stumbling upon exposed ore deposits or locating visible indications of their presence. The second is chemical. Industrial chemists and metallurgists are seeking to facilitate the exploitation of lower grade ores to find methods of recovering valuable metals from common substances. In the third field of effort. lie the activities of the economic geologist and the mining engineer, who en-deavor to locate concealed ore deposits, which would remain hidden from the prospector, no matter. how expert or conscientious he might be. Obviously the task which such a man must face is both exacting and indefinite, and the tools which he has heretofore been permitted to bring to it are, for the most part, abstract-a knowledge of certain fundamental princi-ples and processes involved in the origin, occurrence, structure, and distribution of deposits. of natural re-sources and of the rocks which form the environments of those deposits, and a process-of reasoning by analogy supplemented by the .use of the diamond drill, or such artificial exposure as the test pit, trench, shaft or tunnel. His primary efforts are usually bent on acquiring a knowledge of the distribution of the rocks-as accurate -is possible-which is a natural prerequisite to any conclusion as to how they became so distributed. Over very extensive areas, however, he meets. the extreme difficulty of being unable to see the rocks, except at rare intervals, since .they have been concealed by an overburden of glacial material, of alluvium, of soil, or of other rocks.

Jan 9, 1928

By S. Jess Larsen

Modern technology has provided the world with many innovations to improve living standards, ease of job performance, efficiency, and managerial control. While not expected to compete with the computer revolution, Kerr-McGee Coal Corporation has found a way using laser technology to solve one of their haulage problems. Operating successful and profitable surface coal mine facilities in Wyoming's Powder River Basin require economies of scale, flexibility of operation, conscientious cost control, and ever-present innovative effort. Because haulage costs are the major source of expenditure in surface mining, Kerr-McGee recognized early the need for maximum haulage productivity and the economies of scale provided by large haulage trucks. Special conditions that exist in the Powder River Basin coal fields require consideration. The coal thickness (up to 100 feet and more) and varying depths of overburden dictate that a haulage unit with good gradability characteristics be used to avoid undesirable long ramps. Two and often three coal seams are encountered by most mines, which necessitates operating from several coal and parting faces simultaneously. This situation consumes much space, and to minimize the scope of problems, a coal haulage unit with good maneuverability and stability is needed. Finally, the low density of coal (±1500 pounds/loose cubic yard) demands a large volume capacity to utilize truck load carrying capability effectively. These conditions prompted Kerr-McGee to select unitized two-axle bottom dump trucks of the 160-170 ton size for primary coal haulage at its two Gillette-area mines. Use of 170-ton bottom dump trucks at the Clovis Point Mine handles most of the coal haulage, but the truck

Jan 1, 1983