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By G. B. Gould, F. M. Gibson

IN DECEMBER, 1934, the joint Committee on Fuel Values, of the American Institute of Minim and Metallurgical Engineers and the American Society of Mechanical Engineers, submitted a preliminary report, which briefly stated its conclusion that it was not possible to devise any formula for the valuation of coal, based upon the various physical and chemical properties, that would be generally applicable. That report also listed those chemical and physical properties of coal that are generally recognized to have some effect on its use in steam plants, and those physical characteristics of steam plants which affect, in one way or another the relative importance of the properties of coal used in them. Since then, the Committee has considered and discussed in greater detail the interrelationship of the properties of coal and plant characteristics. The conclusions of the Committee are summarized below, with certain recommendations regarding engineering procedure, which will promote the collection of more easily correlated observations with respect to this subject, and thus advance more rapidly the accumulation of data capable of general application.

Jan 1, 1936

By Charles W. Frey

COMPRESSED air is one of the most useful tools that the mine operator has at his disposal. It is clean, nontoxic, easily handled, and can be distributed anywhere that a man can drag a length of rubber hose. Without it a great deal of drilling would still be a laborious hand process, and although the John Henry of legendary fame could beat a mechanical drill, John Henrys are few and far between, and in the long run the air drill is the victor. As a general rule, horizontal compressors are lubricated by mechanical lubricators, which furnish oil to the cylinder walls, whereas vertical units are splash lubricated. In most horizontal machines oil is introduced at the top center of the piston, from which point it can run down and lubricate the rest of the piston. Some large units introduce oil at more than one point on the cylinder wall, the necessity for this and the number of points of introduction depending upon the size of the cylinder.

Jan 1, 1938

By C. A. Heiland

THIS year's review of geophysical activities has a somewhat different complexion than usual. With the ending of the war, the time seems opportune to supplement the customary report on operations and discoveries in oil and mine exploration by a review out-lining the contributions of geophysicists to the. war effort. To give as much space as possible to the latter, presented as Part 2, some of the usual review features have been omitted from the statistical section, given as Part 1 immediately following.

Jan 1, 1946

By James P. Sloss

WHAT is the likelihood if any-that a real gold mining industry will be developed in the southern Appalachian region? Has the increase in the dollar value of gold from $20.67 to $35 per ounce potency to turn the trick? Suppose it be assumed that the price of gold will, at worst, not recede, and that the cost of digging ore and treating it of which the average level of commodity prices and wages is a fair index-will, at most, not exceed that prevailing in 1926. One may or may not accept these as reasonable assumptions; but one must arbitrarily remove some of the potential variables if one is to get anywhere on a problem like this. As a matter of fact, this article is not going to venture a conclusive answer to the question that has been posed; but it will endeavor to present some of the factors that have a bearing on the problem. The writer spent ten days visiting a dozen properties in Virginia and the Carolinas early in April, 1935, and in doing so got a first-hand slant on mining conditions in the domain of King Cotton.

Jan 1, 1935

By AIME AIME

UNDER the auspices of the Institute's Committee on Industrial Preparedness, a symposium was arranged for the Annual Meeting on the subject "Ores, Metals, and the War," with many well-known Government men and industrialists participating. Wilfred Sykes, president of the Inland Steel Co., of Chicago, presided, with C. K. Leith and Clyde Williams as vice-chairmen, Mr. Williams presiding over the latter part of the meeting. On the Auditorium stage in the Engineering Societies Building was a formidable corps of "experts," with an audience of several hundred to hear what they had to say and to ask questions.

Jan 1, 1942

By Donald M. Liddell, G. C. RIDDELL

THE cosmic ray continues to engage the attention of the physicists, and according to Millikan and Compton, experiments of the past summer indicate that these rays must come from interstellar space, but not from the stars themselves. According to press reports of the International Congress of Physicists at Rome, the view was given there that these rays have an initiating potential of over 750,000.000 volts. In the field of spectrographic investigation great strides have been made. The U. S. Naval Research Laboratories (R. F. Mehl and G. E. Doan of Lehigh) have just finished a year's work with a "radium torch" or "shadowgraphic apparatus" in the field of the X-ray, that bids fair to displace the latter to a great extent. The torch is more powerful., easier to operate and cheaper. Penetration of 10 in. of steel has been accomplished, which. is much -beyond the- -scope-, of the X-ray..

Jan 1, 1932

By Albert Sauveur

IN an important paper on The Critical Ranges of Pure Iron1 presented at the May, 1913, meeting of the Iron and Steel Institute, Professor Carpenter reports and illustrates the results obtained by him in determining the critical points of some very pure electrolytic iron sheet about 0.01 in. thick. The iron strip was rolled into the form of a cylinder 1; in. long and fn in. wide, weighing 42 g., the thermo-couple being inserted in a small hole in the center. The points Ac3 and Ar3 were readily detected, as well as the point Art, but the point Act was absent from every heating curve. The author concluded from this occurrence that the conception of A2 as an independent allotropic change must be abandoned. At the October, 1913, meeting of the American Institute of Mining Engineers, Dr. G. K. Burgess and J. J. Crowe read a paper on The Critical Ranges A2 and A3 of Pure Iron2 in which they described some extremely important experiments conducted by them at the Bureau of Standards, Washington, D. C. They tested Professor Carpenter's electrolytic iron and detected a sharp and well-defined absorption of heat corresponding to the point Act. Professor Carpenter's failure to detect this point is explained by them on the ground that unless the iron be in a single piece entirely surrounding and in contact with the thermo-couple junction, the thermo-couple will integrate the irregular progress of the heat through the sample and the curves will lose their sharpness. In discussing Messrs. Burgess and Crowe's paper, Professor Carpenter accepted this explanation as probably accounting for the absence of Act in his heating curves.

Jan 2, 1914

By GEORGE ROBERT DE BEQUE

WHAT is wrong with oil shale? The answer is of interest to the public, to the oil refiner, and to the engineer. Many people have invested in shale land or shale securities, and others would invest if early development of the industry were certain. In the face of increasing demands for oil products, oil refiners are threatened with inability to maintain present output unless the supply of domestic petroleum is supplemented. Development of the oil shale industry would open a new field for engineering services. The object of this paper is to suggest reasons why there is but one shale plant in operation in the United States, and to discuss the probable time when the business will be firmly established in Colorado. As the Colorado deposits are the richest and largest in the world, ample supply of material is assured, consequently, this discussion will be confined principally to technical problems and economic problems affecting shale development.

Jan 1, 1924

Prof. Henry S. Jacoby, Cornell University,Ithaca, N.Y. (communication to the Secretary): When a simple beam supports any given load, the lower fibers me in tension while the upper fibers are in compression, and if its cross-section is rectangular the neutral surface, where the stresses pass through zero from tension to compression, is at mid-depth, provided the elastic limit is not exceeded. In addition to the longitudinal stresses, there are horizontal shearing-stresses between the fibers which have their maximum value in the neutral surface, and which equal zero at the upper and lower surfaces, while there are also vertical shearing-stresses. Let another beam of the same dimensions be placed on top of this one, and the load be doubled, it then produces stresses in each beam of the same character, magnitude and distribution as in the preceding case, provided there be no friction between the adjacent surfaces of the beams. Next let these two beams be so firmly united that there will be no motion between them when the same load is again applied. All the fibers in the upper beam are now in compression, and those in the lower beam in tension, while the maximum stresses in the outer fibers are only one-half as large as before. The strength of the combined beams is therefore doubled. If, however, some motion occurs between the beams, then the stresses in some of the lower fibers of the upper beam pass from compression to tension, and those in some of the upper fibers of the lower beam from tension to compression, while the stresses in the outer fibers have a magnitude between the two values previously stated. These fundamental facts relating to the flexure of beams indicate the necessity of carefully designing the keys or brace-

Jan 1, 1898

By Jack C. Haptonstall

This paper describes the analytical characteristics of Western subbituminous coal and the manner in which these characteristics apply to their use in a utility-sized steam generator. It compares these characteristics with those of typical Midwestern coal and Eastern bituminous coal. The paper also reviews in detail the design considerations that must receive attention when various blends of these three coals, or any combinations thereof, are planned to be used. This research paper describes variations in analytical and utilization characteristics when coals from different origins are blended in order to achieve a predetermined sulfur content for the purpose of predicting sulfur oxides emissions as they affect environmental regulations and the resulting alterations in utilization characteristics such blending would cause, and how such blends of coal would affect a utility-sized steam generator.

Jan 1, 1979

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

By Michael Perch

The fact that coal is a complex organic material and heterogeneous in composition has made its study extremely difficult, particularly in regard to obtaining a fundamental concept of the processes involved in the formation of coke. It has been stated recently that coals are natural polymers and that in a complex reaction such as occurs during carbonization the differences between coals are quantitative and not qualitative. Such being the case, it would be expected, therefore, that a series of coals subjected to exactly the same conditions of coking would produce results that should be related quantitatively to the chemical analyses of the individual coals. In the past, however, this fact was not generally recognized and consequently many empirical test methods were devised for testing coals. The interpretation of the results obtained depended upon comparing a set of data with other data on coals of known characteristics. The testing procedure had to be con- ducted in precisely the same manner each time and not the least requirement in making the interpretation was experience. The test methods varied from those utilizing a gram of coal to the plant-scale tests in which one or more ovens were charged with the test coal. The aim had been principally to find some simple, inexpensive means by which the coke-making and other properties of coal could be predicted. It is not necessary to emphasize the importance of these endeavors, for anyone acquainted with the problems involved in the selection of coals for making coke is well aware of the time and expense involved in making a series of definitive tests.

Jan 1, 1949

By HORACE H. EJIRICH

(New York Meeting, February, 1912.) PREFATORY NOTE.-The first part of this paper was sent to me by Mr. Emrich nearly nine months ago ; and. I held it, waiting for the second part, which he had promised to forward soon, so that I might submit the whole to some of his former professional associates, and advise him of their criticisms and suggestions before offering his work to the Institute. But, five days before the second part reached me, I received by telegraph the news of Mr. Emrich's sudden death. The paper has therefore not had the benefit of such a revision by the author as might have made it in some respects clearer and more complete. Nevertheless, I believe that experts in the branch of metallurgy with which it deals will find it both original and suggestive.-A. EILERS. I. PARTIAL REFINING IN THE ANODE-FURNACE. During my connection with one of the large New Jersey copper-refineries, and probably before that period, from 15 to 20 per cent. of the copper-bullion received was the very foul, leady blister-copper produced from lead blast-furnace matte. It had been customary to mix a small part of this blister with each charge of purer pig-copper, in the effort to dilute it as much as possible before casting into anodes; but tank-house conditions were such that I was led to try making entire furnace-charges of this blister, and refining it as much as possible in the furnace-afterwards casting to anodes and refining electrolytically, in tanks and solution separate from the main bulk of the purer copper. In making this experiment, notes were made, for several furnace-charges, of everything thought to have a bearing on the question, and some interesting facts were brought out, both in the furnace-working and afterwards in the tanks.

Jun 1, 1912

By Martti E. Maliniemi

The Svappavaara mine is located 47 km southeast of Kiruna C. The ore deposit now being worked, Leveäniemi, belongs to Luossavaara- Kiirunavaara AB (LKAB) and is the company's, and also Sweden's, third biggest mine after Kiirunavaara and Malmberget. The distance by rail to the Norwegian port of Narvik is 214 km and to Lulei on the Gulf of Bothnia 340 km (Fig. 1). The village of Svappavaara has about 800 inhabitants. The climate is arctic in character. The temperature during the months of December to February is about -20º to -35ºC, and the ground is covered by a blanket of snow for about eight months of the year. The brief, intensive summer often arrives with startling speed, bringing both sunshine and warmth. HISTORICAL BACKGROUND Mining operations took place in Svappavaara as far back as 300 years ago. During the period 1655-1684, copper ore was taken from the deposit called Gruvberget in the vicinity of the village. The total production of raw copper was probably about 1,045 tons. During the 18th and 19th centuries, several attempts were made to extract iron ore from the numerous deposits found within the district. These brave attempts, however, were foiled by the high phosphorus contents and the enormous transport difficulties. The present-day mine fields in Leveäniemi were discovered in 1897. At that time, it was difficult to determine the size and value of the deposit because of the thickness of the soil cover (3 to 15 m) and the

Jan 1, 1969

By William L. Saunders

MANY members of the Institute, who participated in the visit made, during the Bethlehem meeting of February, 1906, to the shops of the Ingersoll-Rand Company, at Phillipsburg, N. J., inspected with interest the new Electric-Air drill, which the company had set up for the purpose of showing it in actual operation to American. mining engineers. At the request of the Secretary of the Institute, I promised at that time to prepare a paper for our Transactions, describing the construction and advantages of the machine. But such a paper would then necessarily have contained much that was only expected or claimed by the designers and manufacturers of the drill, and not yet incontrovertibly proved by varied and long-continued practice. However moderate such statements might have been, they would have given inevitably to the paper, to some extent at least, the air of a prospectus, rather than of a technical contribution. I therefore decided, with the Secretary's approval, to postpone the writing of the promised paper until it could set forth the results of adequate actual practice, as well as the latest details of construction, etc., based upon practical experience. That period has now arrived. The Electric-Air drill has been exhaustively tested in the field, under varied and arduous conditions and upon the hardest rocks. It is now fairly in the field; its merits and performances are matters of unimpeachable record, and its place among established competitors can be definitely determined. As a representative of the Ingersoll-Rand Co., as well as a member of the Institute, I may be permitted to add that my company, being largely interested in the manufacture of air-

Jan 9, 1907

By Carleton Ellis

(Presented at a meeting of the New York Local Section of the Institute, Apr. 12, 1912.) I. INTRODUCTION. THE problem of the influence of hot surfaces upon gaseous combustion is one which, from a purely scientific stand-point, has engaged, for many years past, the attention of Prof. William A. Bone, of Leeds University and the Imperial College, London; and as his recent work has been the direct outcome of earlier scientific investigation, it will be appropriate, by way of introduction, to review briefly the present position of science with respect to this important subject, as stated by Professor Bone. One may perhaps best arrive at an understanding of the term " ?flameless " or " surface " combustion by considering certain facts which differentiate it from the more familiar processes of combustion as they occur in ordinary flames. All hot surfaces have an accelerating influence upon chemical changes in gaseous systems. If, at any temperature, a gaseous system, A, tends to pass over into another system, B, contact with a solid at the same temperature will accelerate the process. To take a very simple example, if a mixture of hydrogen and oxygen in their combining proportions (electrolytic gas) were maintained in an inclosure with smooth glass walls at a temperature of, say, 450° C., there would certainly be a tendency to form steam, but the rate of change would be negligibly small. If, however, there were brought into the system some porous solid material at the same temperature, so that a large surface was exposed to the gases, the rate of change would at once be rapidly accelerated in the layer of gas immediately in contact with the hot surface. Steam, the product, would diffuse outward from the surface, and the supplies of hydrogen and oxygen at the surface would be renewed by diffusion inward. Thus combustion would proceed heterogene-

Sep 1, 1912

By M. D. Cooper

IN spite of the uncertainty in the bituminous coal industry during 1933, progress worth recording has been made. Along with other industries, coal has felt the effects of business stagnation, but even in the worst weeks of the past four years, .the total production of bituminous coal in the United States was seldom less than half the production in some of the best weeks of the more prosperous years, a record better than that of many industries. However, the competition of other fuels and sources of power, together with the increased efficiency in the use of coal, has brought anxiety to producers. This has resulted in pressure for reduction of costs, not always by the wisest means. On the other hand, the effort to survive has directed increasing interest toward research, a wholesome development in a difficult situation. Wages, limitation of hours of labor, and the NRA have occupied much time and thought. Following a period .of wage cutting paralleling price cutting, the industry found itself rather suddenly faced by the President's Agreement, followed in due course by the Code, and then in many places by the agreement with the United Mine Workers. Although there is still some uncertainty in regard to the detailed working out of the new arrangements, there seems to be an honest endeavor by the signatories to the Code and Agreement to work them out in a straightforward manner.

Jan 1, 1934

By T. R. Wright

THE Corporation operates concentrators in four camps: Casapalca. Morococha, Cerro de Pa-co, and Mahr. The present concentrator at Cerro de Pasco is the newest having been completed in 1943. and that at Casapalca the oldest, having been built originally as a gravity concentrator, in 1889. Prior to 1925 the Corporation's milling operations were confined to the beneficiation of silver-bearing copper ores, and treatment of these ore: by flotation was started in 1918. Although fairly large deposits of complex, fine-grained lead-zinc ores existed, little progress had been made in the treatment of such ores--in Peru or elsewhere-until the early 'twentics. The Casapalca concentrator began the selettive concentration of complex leadzinc ores by all-flotation methods in 1925, or contemporaneously with the commercial development of selective lead-zinc flotation in the United State:.

Jan 1, 1945

By Henry S. Washington

Introduction. It Still Rains On The Choco ! I Well Remember One Evening A Dozen Years Ago, While. Traveling Toward The Town Of Negua In A Small Champa Or Dug-Out Canoe, The Rain Fell So Heavily That I Had To Work My Hardest To Bail Out The Water With A Large Totuma Or Gourd In Order To Keep The Canoe Afloat, The Senegambian Meanwhile Plying His Paddle In The Stern. If Any One Thinks Bailing Is Easy Work, Let Him Scoop Out A Quart Or More At A Stroke, 40 Times A Minute For Half An Hour, And I Venture That He Will Change His Opinion. These Small Canoes Required Only One Paddler, To Make The 3 Miles An Hour Which Is The Standard Rate Of Aquatic Progress On The Choco. Another Time, On The Atrato River, About Six O'clock In The Afternoon, The Rain Fell So Heavily Than An Empty Gourd, 9 In. In Diameter And 4.5 Deep, Was Filled To The Brim In 90 Sec., Timed By A Watch. Such Downpours Are Typical, But Unless Caught In One It Is Not Specially Noticed. These Downpours Seldom Last More Than An Hour, And Frequently Cover Only A Limited Area, Occasionally Falling On One Bank Of A River And Not On The Other. During The Night-Time,' The Rain, If Gentle, Will Usually Last Until Dawn, And Sometimes An Intermittent Drizzle Will Keep Up All Day As Well, Although, As A Rule, It Rarely Rains During The Day. The Rise Of The Rivers, Due To The Rain-Fall, Varies From A Few Inches To Several Feet. One Night In August, 1899, The Spuds Of The Dredge Margaret, Operating On The Atrato River, Showed A, Rise Of 16 Ft., And For 3 Days Thereafter Occurred The Greatest Flood Known In That District For 32 Years. The Dredge Had All Three Spuds Clown, And The 2-Yd. Shovel Dragging On The Bottom. A 0.75-In. Cable Fast To A Stout Tree, 700 Ft. Away, Stretched Tight

Sep 1, 1908

By John B. Hastings

THE occurrence of such a large amount of gold in the Hartsel granite, even though the surmised existence of similar areas is not new, brings freshly to mind the pegmatite type of magmatic differentiation lately brought again to attention by occurrences at Silver Peak, Nev., described by Spurr; and in Alaska, described by both Spurr and Brooks. In both localities graunitic rocks or dikes are thought to pass into metalliferous quartz-veins. An interesting association in this connection is the occurrence of diamonds in residual pegmatitic clay of San Juao de Chapado, Brazil, described by Derby :1 (P. 142) "Bodies of pegmatite are quite common in the older rocks of Brazil, both in the. diamond regions and elsewhere, occurring not only in the gneiss and granite, but in the schistose series as well. Those that have been examined are dike-like in their mode of occurrence and granitic in composition." (P. 143) "The question of the eruptive or secretionary origin of pegmatites has long been a subject of discussion among geologists. . . . The recent studies . . . seem to have clearly established that most if not all of them are essentially eruptive masses, though possibly modified in some way by aqueous agencies. Even before becoming acquainted with the literature of the subject this view had seemed to me to be the only acceptable one as regards the typical pegmatites of Brazil." What is pegmatite ? J. F. Kemp says ". . . veins or dikes-it is an open question which is the more correct term-are met formed of very coarsely crystalline aggregates of the same minerals that constitute granite. These are called pegmatite and in them is the home of graphic granite, the curious intergrowth of quartz and feldspar, such that a cross fracture of the blades of quartz suggests cuneiform characters. . . . In regard to the larger veins or dikes it seems improbable that true igneous fusion could have afforded such coarsely crystalline aggregates, and so we are forced to assume such abundance of steam and other vapors, i.e, mineralizers, as to almost, if not quite, imply solution."

Jan 5, 1908