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By Perry Harrison

THE mixing of fine ores with fuel and burning under induced draft is called sintering in iron-ore practice and either sintering or roasting in copper and lead metallurgy. The first development of sintering was the Huntington-Heberlein process, in which fine sulfide ores mixed with fuel were charged into a pot and burned under the action of an upcast current of air introduced at the bottom of the pot. Modern development has resulted in two types of machine; the continuous Dwight-Lloyd machine, which consists of heat-resisting grates and a moving beltlike type of hearth constructed of metal, in which air is drawn downward through the bed, and the stationary Greenawalt batch process, which operates in the same manner as the Dwight-Lloyd except that the hearth is stationary. The recent rapid increase in the use of sintering has been the result of two great advances in metallurgical process-flotation and the treatment of flue dust. The Dwight-Lloyd machine is used in many plants for agglomerating flotation concentrates and at the same time reducing the sulfur content to furnace requirements and it has become standard practice to treat iron blast-furnace flue dust by either the Greenawalt or Dwight-Lloyd machine, so that it can be recharged into the furnace. The mining of low-grade magnetite iron deposits and their beneficiating by grinding and magnetic separation resulted in a fine concentrate extremely detrimental to blast-furnace practice. These concentrates are sintered and made into ideal material for blast-furnace use. Incidentally, coke savings of about 400 lb. per ton of pig are reported.

Jan 1, 1930

By Leonard Larson

DURING several years immediately preceding the adoption of wet-charge smelting at McGill, various necessary conditions affecting this procedure, such as plant rearrangement and the metallurgical nature of the concentrate produced at the concentrator, were fully considered. Wet-charge smelting is not altogether novel to the recently reconstructed smelter at McGill. A number of years prior to this improvement, when flotation methods were initiated at the concentrator, large tonnages of wet and (at that time) sticky flotation concentrate were charged directly into the reverberatory furnaces, because of the difficulty in handling the entire tonnage in the roasters. The plant had excess reverberatory units and this surplus furnace capacity was utilized to smelt raw flotation concentrate. During the years 1927 and 1928, a number of actual operating furnace test runs were made to determine in principle the feasibility of wet-smelting operation. Results were encouraging, and in November 1932 the roasting plant was shut down. For some time thereafter the wet feed was delivered directly to the reverberatory side-charging calcine hoppers already in place. Feeding the wet material through the old calcine hoppers and charge holes into the furnace involved considerable labor, but under the conditions existing at that time it was desirable to continue wet smelting even under the handicap of this laborious procedure. The smelting plant during this period was on a curtailed production basis, operating only about 15 days per month. The alternate starting up and shutting down of the roasting plant presented a difficult problem and charging the wet material directly to the furnace entirely eliminated this difficulty. The roasting plant was never operated thereafter. EARLY PROCEDURE Fig. 1 shows the general layout of the smelting plant before the smelter was remodeled. Under this arrangement, all concentrates and fluxes except converter flux were delivered in cars to wooden storage bins, which paralleled the roaster building. The material to be roasted was dis-

Jan 1, 1938

By A. B. Kinzel

SINCE the exposition of the behavior of certain iron alloys by Sykes1 involving the existence of an austenite loop and the discovery of such a loop in the chrome iron system by Bain,2 there has been much conjecture both on his part and on the part of metallurgists in general as to the exact shape and location of this loop. In previous work commercial steel has been used and the microscope has been employed to locate the critical points so that the position of the loop has been quite approximate. Numerous attempts have been made to measure the critical points of the carbon-free alloys but all of these for one reason or another have failed. A satisfactory method for studying these phenomena, is presented here. MATERIAL The first difficulty in this study was to obtain pure chromium-iron alloys. This has been overcome by melting in a vacuum electrolytic iron and chromium analyzing 99.84 Cr, Fe and C. A pure magnesite crucible was used and the melt allowed to solidify in the crucible. A typical analysis is chromium, 10.10 per cent., carbon, 0.006 per cent., silicon and manganese nil. To overcome the problem presented by segregation, ingots were made into wire 0.04 in. in diameter. This was accomplished by hand-forging the ingots into rods, using an oxyhydrogen flame for heating, in order to avoid carbon. Subsequently the rods were swaged too wire, the heating being carried out in hydrogen. Thus local segregation was eliminated although differences in analysis between portions 50 ft. apart were noted. An electric-resistance method was first tried to determine the critical points, but due to the physical defects in the wire this failed. Bain had previously shown the presence or absence of critical points in a qualitative way by observing the sag in a catenary. The author has devised the following method which gives an accurate determination of the critical points from expansion-temperature curves of suspended wire, a special telescopic dilatometer being used for the purpose.

Jan 1, 1928

By Foster Bain

THE outstanding characteristic of the last hundred years has been the world-wide rise in the standard of living. Man's dominion over nature is increasing with an accelerating pace and more and more the forces and materials of this world are being made to serve man's necessities and his convenience. We demand both quantities and varieties of goods that were beyond the dreams, to say nothing of the reach, of our fore-fathers, and our possession of them has become so much a matter of course that they excite no remark. Literally, thousands of young folks have required an explanation of a recent popular song, "Thanks for the Buggy Ride," for the reason that their own experience does not extend back into the pre-flivver age. This transition from the use of vehicles made mainly of wood and drawn by animal power, to metal made cars propelled by mineral fuels is all but complete and the memory even of older conditions is already fading. This is symbolic of what is happening all around us. In a recent book, Dr. Frank J. Goodenough, president of Johns Hopkins University, referred to Chinese civilization as a ?vegetable" civilization meaning thereby that the Chinese depend mainly upon the plant world for food, clothing and other necessities and luxuries. Our own people did the same hardly more than a hundred years ago. In 1820, this country produced and used only 5 lb. of pig iron per capita, but a quick and enormous change was wrought in the hundred, years that followed, and in 1920 the amount was 119 times as much, or 597 lb. It has since increased even beyond this and touched a peak of 809 lb. in 1923. In that year our output was more than twice that of 1903 and nine times that of 1883. This increase in production

Jan 10, 1926

By M. MacFarland, E. McAuliffe

Our North American railway system, including the lines serving the United States, Canada and Mexico, with a total operating mileage of 303,040, employing 71,818 locomotives, represents not only the greatest industrial user of fuel coal, but in the variety of coals used, ranging from anthracite down through the several gradations of bitumirlous coals, as well as lignites, covers about all there is in American-mined coals. Necessarily the wide range of fuel coal embraces not only extremes of calorific value but also every possible gradation shown in size and preparation, from run of mine to washed nut and slack. Approximately 8 per cent. of the fuel used by the railroads is consumed in shop power plants, shop buildings, pumping stations, station buildings, etc. The principal class of coal (as designated) used by the railroads is bituminous, such, however, including a substantial tonnage of subbituminous and lignite coal; all United States railroads using in 1923 for locomotive, shop, station buildings and miscellaneous uses, a total of 4,578,000 tons of anthracite, 155,795,000 tons of bituminous, subbituminous and lignite coal and 58,005,000 bbl. (42 gal.) of fuel oil. The Class 1 railroads of the United States (those whose gross annual earnings equal or exceed $1,000,000) used in 1926: Bituminous, subbituminous and lignite coal, net tons..... 140,083,885 Anthracite, net tons................................ 3,667,505 Fuel oil, gal........................................ 3,058,915,511 Railroad fuel-purchasing agents rarely attempt to classify coal for locomotive use on the basis of chemical analysis; although this is very generally used as a guide in the initial selection of a fuel supply. The extraordinarily high rate of combustion developed in the modern locomotive, generating as high as 2500 b.hp., with limited facilities for cleaning fires en route, suggests the importance of a fuel supply containing a reasonably low percentage of ash-making material, and while the percentage of locomotive coal handled through automatic stokers is growing, the principal tonnage is yet fired by hand.

Jan 1, 1930

By A. C. Fieldner

A FORMER paper1 described in detail various methods of calculating coal analyses to obtain the composition and calorific value of the pure coal substance-that is, of the coal free from its mineral matter. The paper included a table showing calorific values of pure coal, as calculated from float-and-sink portions, by means of the Parr formula for "unit coal" and by the customary moisture-free and ash-free formula. A modification of the Parr formula was proposed, based on the assumption that one-half the sulfur present in coal occurs as pyritic sulfur and one-half as organic sulfur. In the published discussion of the paper Cady gave a table of results on a large number of Illinois coals as obtained by the Parr formula and the proposed modification thereof. The results obtained by Cady indicate that the Parr formula applies better to Illinois coals than does the modified formula proposed by Fieldner and Selvig. The present paper gives results obtained by applying the modified Parr formula to the analyses of the float-and-sink portions of the coals shown in the former paper, and results obtained by applying the Parr formula, the modified Parr formula, and the simple moisture-free and ash-free formula to various coals of the United States ranging in sulfur content from less than 1 per cent to more than 4 per cent sulfur. A graphic method of estimating the calorific value of pure coal and determin-ing the relation of the coal ash to the mineral matter of coal, as proposed by Stansfield and Sutherland,2 was applied to a number of coals, and the results are given herein.

Jan 1, 1932

By Charles H. Jacoby, Leo E. Read

IN diamond coring salt beds to evaluate deposits, special techniques are applied to standard slim hole drilling to obtain a representative sample of the water soluble sodium chloride. Industrial consumers generally require a run-of-the-mine material of 98.0 pct sodium chloride. Since no commercial beneficiation has yet been devised to upgrade the lower quality salt beds, the only processing is crushing and screening to the size required by the customer. Coring salt sections has recently become important not only in dry mining, but also in the development of brine cavities by hydraulic fracturing and the formation of jugs for storing liquid petroleum products. Drilling Fluid: The fluid used in coring salt beds in New York, Ohio, and Michigan is a thoroughly saturated brine made from 3.0 lb rock salt per gal of make-up water. This mined rock salt, -4 mesh +10 mesh, is dissolved in a lixator, a double-bottomed cone hopper that turns fresh water to fully saturated brine.

Jan 5, 1957

By J. R. Thoenen

THE preper classification of mining methods has received the earnest study of many mining engineers and has resulted in much technical controversy, depending no doubt upon the point from which classification is viewed or the use to which it is put. So far as the writer is aware, the discussion has invariably centered around the classification of underground mining methods, and only superficial attention has been directed to surface methods. Volume 72, page 10, of the Institute Transactions, presents such a classification, sponsored by the Mining Methods Committee of the Institute. A similar classification by Prof. Hugh P. Nicholson appeared in Mining and Metallurgy in October, 1934. The two classifications are quite different in their treatment of underground methods but are identical in classifying surface methods, although Professor Nicholson does suggest possible further divisions for surface mining and admits that such subdivision is more difficult than appears at first. Surface subdivisions as given by these two authorities are as follows, showing that in spite of rearrangement the two classifications are identical: From his experience of many years in the study and operation of both underground and surface metal and nonmetallic mines, the writer does

Jan 1, 1942

By Robert Glass Cleland

WITH the acquisition of the Nichols Copper Company ' and the development of the large Copper Products manufacturing and selling organization, the Phelps Dodge Corporation had attained two of its important goals. But at that particular time both its immediate and long-range prospects were giving the company serious concern. The financial panic that began late in 1929 was growing worse instead of better. Neither raw materials nor finished products could find a market. In 1932 the price of copper fell to the almost unprecedented figure of four and eight tenths cents a pound. Domestic production of copper in the United States was further threatened by a large low-cost output from the mines of Africa and the Andes. Canadian copper mines, with their large yield of other valuable metals from the same ores, added to the difficulties of the American companies. After a hard-fought campaign, however, the producers of domestic copper finally induced Congress to levy a duty of four cents a pound on copper imported into the

Jan 1, 1952

Since 1571, when the Institute was founded, many of the most important papers in the English language, on the various phases of mining and metallurgy, have appeared as Institute publications. As members of the Institute regularly receive the publications in which they are interested, this discussion is primarily for nonmembers who wish to know of them. The Institute has several means of issuing papers which have been submitted and accepted. The monthly journal, Mining and Metallurgy, is the magazine of the Institute. In it appear notices and reports of official business as well as many papers and contributions which do not appear otherwise. The annual subscription price of the magazine to nonmembers is $3 per year; Canadian and foreign postage $1 extra; single copies 50 cents; back issues $1 each. Many papers are published separately each year. They are issued in one or the other of two numbered series; namely, Technical Publications and Contributions, and of the latter there are four forms: Preprints, Mimeographs, Reprints, and Unpublished Manuscripts. A Technical Publication or Contribution (in any form) is issued by the Institute when it is listed in Mining and Metallurgy. Technical Publications are sent automatically to members who have asked in advance for papers on a given subject. All members are entitled to a copy of every paper in either series, except when a Contribution is an Unpublished Manuscript. Con¬tributions in the form of Unpublished Manuscripts are filed in the Engineering Societies Library and copies of some of these papers may be found in a few selected libraries throughout the country.

Jan 1, 1933

By Robert L. Taylor, Richard E. Goodman

A complete rational analysis for design of excavation slopes and loaded rock masses is a desirable but perhaps unattainable goal. Irregular external and internal boundary conditions, poor understanding of failure criteria for large masses of rock, capricious material properties, and the importance of indeterminate forces and inaccessible and virtually unsampleable rock defects emphasize the importance of experience in this aspect of rock engineering. The experience must be correlated with geological factors. In certain regions the accumulation of such experience through the observation of existing rock slopes in various formations constitutes an important aspect of studies for design of rock excavations. In former times an accepted method of rock construction consisted of trials and adjustments. This approach is not often compatible with present methods of contract management. With the development of improved instruments and warning devices such as inclinometers, piezometers, relays, stress meters, and rock noise detectors, modified trial procedures of rock construction may reappear in specific applications. In spite of the great advances made, development of methods to predict the performance of rock slopes, abutments, and foundations deserves vigorous effort. Two distinct approaches may be taken. The rock mass in question may be considered a continuum and the stresses and strains throughout the region of influence of the work may be calculated. Or, the rock mass may be described as a discontinuum whose stability calculation involves the statics and kinematics of accumulations of rigid blocks. The prototype must lie in the range between these contrasting models. As yet, however, there is little reconciliation between the two methods

Jan 1, 1967

By Arthur Taggart

FOREWORD THE tests herein described are part of an extended series of experiments, performed by the authors together with J. F. McClelland and L. W. Bahney, on the reclamation of metallics from foundry and manufacturing-plant scrap. The most obstinate problem encountered was the proper cleaning of the metal. INTRODUCTION In the manufacture of brass and brass products the weight of the finished product leaving the plant is much less than the total weight of copper and zinc entering. A small part of this discrepancy is due to the unavoidable oxidation of the metals in melting, but by far the largest part of the loss is in the form of metallic particles of copper, zinc, and brass. These losses occur principally at three points in the process: (a) in the casting-shop ashes; (b) in the slags from furnaces melting scrap brass; (c) in material spilled on the floor throughout the manufacturing process. The amount of these products in some plants is nearly 100 tons per 24 hours. Casting-shop ashes contain the metal spilled from the crucibles during melting and pouring, and the metal included in the slags formed in the melting process. The ashes also contain pieces of broken crucibles with adhering metal; 20 to 30 per cent. of unburned coal is also present. The metal in casting-shop ashes contains clean pieces of zinc or copper ingots weighing 1 to 2 lb., jagged pieces of metal of all shapes ranging in size from several inches down to the finest dust, and shot and botryoidal shapes ranging in size from 2 or 3 in. down to 0.01 mm. or less in diameter. Slags from furnaces melting scrap brass contain metal in the form of small shot.

Jan 2, 1916

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 K. L. Ludeke, A. D. Day

For many reasons, it appears that deep rooted, perennial shrubs offer potential for improved stabilization and provide maintenance free vegetative cover to harsh sites where perennial grasses have not been successful. The major objective was to select various shrub species of arid plants for initial soil stabilization of disturbed mining areas. The very fact that a drought-adapted shrub has a massive root system that can use moisture from a greater volume of mineral waste soil materials suggests that arid environment disturbed soils may be vegetatively stabilized using desirable forage shrubs. A secondary effort is underway to assemble information and plant materials of promising species from many arid regions of the world for reclamation of mined lands. Surprisingly, many of the better plants for arid sites are quite high in protein content. With proper management, breeding, and selection, they may prove to be very desirable livestock feed when mined lands are used in range land areas. Advancements in arid land solid waste stabilization hold favorable promise for many industries that mine and mill in arid regions for effective reclamation of disturbed areas. Particularly exciting is the possibility of establishment of high density maintenance free vegetative cover of climax vegetation that reclaims the disturbed area back to its original land use. Due to high shrub productivity, stabilization potential, nutritional quality, and reclamation success, greater use should be made of shrubs in disturbed land reclamation associated with mining and milling operations in harsh aril environments.

Jan 1, 1986

By Paul R. Wieber, Atam P. Sikri

This paper describes the U. S. Energy Research and Development Administration's (ERDA) program to develop in situ coal conversion processes, especially gasification. The potential of this technology, the technical directions being explored, and the program strategy to carry the process concepts toward commercialization are emphasized. The geographic location of the U. S. coal resources and a market analysis are described. Commercially successful in situ coal processes could add over a trillion tons of coal to the U. S. coal reserves. The economics of these processes is compared with surface gasification. Independent studies show this process to be 25% cheaper than surface gasification for Western coals. The major projects are briefly described. The Linked Vertical Well process is in the most advanced stage and shows great promise. The last test produced a low-Btu gas averaging 171 Btu per standard cubic foot for average production rates of 8.5 million standard cubic feet per day. The other projects are Packed Bed, Longwall Generator, and Steeply Dipping Beds. Unique factors of the process development are discussed which may lead to commercial processes in the near term. A development strategy is proposed by which this technology could be commercialized before 1983 with potentially lower gas prices and lower environmental impacts, relative to mining plus surface gasification.

Jan 1, 1979

By Blamey Stevens

It is now generally agreed that most metals have been brought to the surface of the earth by volcanic agencies. The question as to how these metals came from the volcanic matrix to the mineral deposit has been often discussed. It might be useful to give more serious consideration to the ultimate origin of the volcanic material. It is possible that some light might thus be shed on the persistent associations of some metals with certain particular kinds of rocks. For example, the very general association of gold with acid types of igneous rocks, of tin with granites or quartz-felsites, of certain types of deep-seated copper-deposits with magnesian eruptives, and so on. One interesting question is as to whether the metals brought near the surface by volcanic agencies appear here for the first time, or whether they came from the central core of the earth. The interior of the earth is, without doubt, much more highly metallic than the crust, and so the core is often thought to be the origin of many of the metals which are uncovered by man. The Differentiation Theory.—Although a great many theories bearing upon these matters have been discussed,' the only one now considered as worthy of much consideration among American geologists is the " Theory of Differentiation of Igneous Magmas."2 According to this theory, lakes of molten magma are supposed to exist very far down beneath the earth's surface. In these lakes a process of differentiation is supposed to be going on whereby the liquid magma is split up into two or more liquid phases. Each of these phases is supposed to take with it the metallic constituents for which it has the greatest affinity.

Jan 1, 1913

By L. G. Austin

INTRODUCTION Autogenous (including semi-autogenous) grinding has probably been the most important single innovation in milling practice for the last twenty years. However, the design of these units has been largely a matter of trial-and-error, since the normal empirical laws for the design of ball mill circuits do not apply with exactitude to autogenous grinding circuits. There have been examples of autogenous mills failing to achieve output or product specifications. It is worthwhile, therefore, to attempt to develop a more detailed and precise set of design laws, using the concepts of specific rates of breakages and daughter fragment distributions (1), and performing mill simulations by computer. This type of approach has been applied to ball and rod milling (2, 3,4,5), but even for these mills it is by no means complete as yet (6), because of the amount of experimental work involved. There has not been a strong incentive for industry to develop new design procedures in ball and rod milling because the prior back-log of experience with these mills makes for easy design by empirical comparsion with existing systems. The new approach has been followed mainly by University groups (7,8,9,10), although experience in Australia (9,11) has shown the advantages of the approach. Stanley (12) has applied the approach to results from a large autogenous mill, and we will use many similar concepts to his work, but extend the concepts to a more

Jan 1, 1977

By Robert F. Love

Deep under the hills of southwestern Wyoming lies a nonmetallic mineral deposit of incredible dimensions and value. This nearly pure, horizontal bed of the mineral trona, a sodium sesquicarbonate (Na2HC0,.NaHC08.H20), is found in the Green River formation some 1500 ft below surface. It is believed that evaporation of an ancient saline lake left this sodium carbonate as the evaporite and mysteriously left practically no sodium chloride, which is the common constituent of an evaporated saline lake. The trona bed averages 10 ft in thickness and extends over an area of several hundred square miles. In 1938 a geologist with the U. S. Geological Survey identified the trona in the core from a former oil exploration drillhole. By so doing, he initiated the developments of a chemical industry of impressive growth in the area, an industry on the threshold of further and much more spectacular growth. A drilling program by the Union Pacific Rd. and Intermountain Chemical Co. in the early 1940's succeeded in blocking out mineable reserves of several hundred million tons. Development of the deposit started in 1946 with the sinking of a 12-ft diam, concrete-lined shaft 1500 ft deep-followed by construction of a small pilot calcining plant. Actual mining of the trona started in 1947 and continued on a limited scale until 1953, when the $15 million surface facilities were completed, along with the second shaft and other expanded underground facilities. Since April 1953 the mine has been producing more than half a million tons per year, from which the refining plant has produced more than 300,000 tons per year of high quality soda ash.

Dec 1, 1956

By R. E. Bedworth, N. B. Pilling

The corrosion of metals is one problem on which time and thought have been expended for many years. In the effort to avert the destructive action of a hostile environment, attention has been directed almost entirely to the conditions under which most metallic structures are called upon to perform, and the extensive and complicated phenomena attending the corrosive action of atmospheric agencies, acting at the ordinary atmospheric temperatures, have been studied, but there is unanimity of opinion regarding many fundamental facts. One neglected phase is the corrosive action of various gases upon metals exposed to temperatures considerably higher than the atmospheric range, and more especially the attack of atmospheric oxygen upon exposed metallic surfaces. That the problem is difficult is connoted by the practical dominance of industrial electric heating by alloys of one type (nickel-chromium). Proprietary interest may account, in part, for the paucity of information available upon even the most general factors determining the behavior of metals and alloys when exposed to such exacting conditions. The present paper gives some conclusions reached as the result of experimental work, extending over several years, on the mechanism and contributory factors of the high-temperature oxidation of a number of simple unalloyed metals; it is free from experimental detail and proof. High-temperature metallic oxidation may be considered as a phase of metallic corrosion. The scheme outlined below, in which corrosive agent and environment are the principal criteria, is one way of analyzing the several groups of corrosion phenomena. Erosion.—Disintegrating or destructive action by physical causes. Corrosion.—Disintegrating or destructive action by chemical causes. Low-temperature Corrosion.—Solid participating phases essentially immobile: (a) Gaseous agent; (b) liquid agent: action electrolytic and action non-electrolytic. High-temperature Corrosion.—Solid participating phases possess diffusive mobility: (a) Liquid agent; (b) gaseous agent: reducing gases, oxidizing gases. (1) Water; (2) miscellaneous elemental and combined oxygen.

Jan 1, 1923

By Eugene Guccione

FOREWORD-At the SME-AIME meeting in Las Vegas this year, the SME Publications Board and the MINING ENGINEERING Committee decided that a fitting way of celebrating the United States' bicentennial would be to publish an article in ME covering the great men in American mining. After some discussion as to the inclusion of financiers -men such as William Randolph Hearst, J. Pierpont Morgan, etc.-the group agreed that the feature should be restricted to the "nuts-and-bolt people," e.g., mining engineers, geologists, mineral processing engineers. Thus, from the AIME All Institute Honors roll and from the SME Awards list, the group chose these 11 historical figures: Herbert Hoover, Daniel C. Jackling, Henry Krumb, James Douglas, Rossiter W. Raymond, Hal W. Hardinge, Seeley W. Mudd, Erskine Ramsay, Howard N. Eavenson, Robert A. Richards, Arthur F. Taggart. What follows is an account of each of these great miners' achievements and the problems they faced, and an assessment by some of today's mining leaders of the challenges that lie ahead.

Jan 7, 1976