Search Documents

By J. L. Wright

When management is confronted with the risk of constructing a waste disposal well, these are some of the questions which may arise. Should the company expand the present waste treatment plant? More lagoons will cut into valuable acreage which might be needed later, and yet the pollution engineer says he can guarantee results. On the other hand, does the formation being used for those successful disposal wells off to the west extend over far enough to be used for the company's own well? Will the formation be thick enough? Will it be too deep? Will it be porous and permeable enough? Apart from needing to make a profit on the products made at the plant, plant officials must sometimes act under pressure to comply with pollution standards. The manager must build the cost of the pollution control system into the price of the products made by the company.

Jan 1, 1970

A B Cummins President James C Gray, President-Elect J W Woomer, Past President C E Lawall, Eastern Regional Vice-President Donald W Scott, Central Regional Vice-President H C Weed, Western Regional Vice-President Nathaniel Arbiter, Treasurer John Cameron Fox, Secretary AIME 29 W 39 St New York 18, N Y

Jan 1, 1960

By Don Simon

In the late 1960s the mining industry was in an apparent slump due to a combination of factors. Enrollment dropped significantly at schools offering mining engineering degrees, resulting in a shortage today of experienced mining graduates to staff middle management positions. How has this limited supply affected salaries? Does the shortage impair the mining industry's ability to respond to national energy needs?

Jan 12, 1979

By C. G. Goetzel

Until recently porous bronzes have found many applications for self-lubricating bearings in the automotive, electrical, household appliance and general machine industries. The bulk of an annual production of several million pounds of copper powder had gone into the manufacture of these articles, of which by now more than a billion are in service. However, the war has brought severe curtailment of these bearings because of the scarcity of the two main constituents, copper and tin. The development of substitute materials of equal or superior properties has led to a large-scale replacement by products made from iron powder. In spite of the diminished interest in powdered copper-tin alloys caused by this trend, it was believed worth while to investigate some mechanical properties of these materials as a reference base for substitutes. In addition, experiments using the hot-press method were incorporated to investigate possibilities of saving vital equipment or opening new fields of applications. It must be assumed that by this time the powder metallurgy process of making porous bronzes, a development that found its first industrial applications more than 10 years ago, is well known in engineering. The patent literature and bibliography is volu- minous, most publications referring to porous, self-lubricating bronzes, containing about 10 per cent tin and I to 5 per cent graphite, with porosities in the range of 25 to 35 per cent.l-7 The excellent antifriction properties of these bearings, caused by the uniform impregnation with oil, are dependent on the interconnection of the pores and the uniform distribution of the graphite inclusions. The sintering mechanism of porous bronze, with its structural changes during the transformation of the metal powder into the sintered bearing has been shown in colored photomicrographs by Hall.* Diffusion between copper and tin was found to begin within one minute, when tin-rich transitory phases were formed. After 25 min. a homogeneous matrix of alpha was reached for an alloy containing 9.5 per cent tin and 6 per cent graphite. Price, Williams and Garrand,9 studying certain metal powder combinations in which sintering is accompanied by the cementing action of a liquid phase, including a 90-10 bronze sintered at 925°C., have found that if the treatment is carried out within the liquidus and solidus temperature range of the system, a peculiar process of alternate solution and precipitation occurs. The particles of the major solid constituent are dissolved in the minor liquid phase, but thereafter are reprecipi-tated on certain nuclei, which develop into large grains, usually rounded.

Jan 1, 1945

By P. C. Kelly

The processes involved in turning a set of seismograph records into a geological structure map may be divided into three classes; (1) picking reflections on the records, to be used for the computations; (2) determining the basis on which the computations should be made in order to arrive at correct results; (3) making the necessary computations and plotting sections and maps. The first is usually done by the crew chief, or at least checked by him. The computing system usually originates in the head office, occasional consultations with the party chief providing modifications as necessary to meet special conditions. The computations and plotting are done by the party computer, with possibly one or two assistants if the calculations require much time. Picking the Rejleclions Marking of the reflections on the records is perhaps the most important step and the one most likely to determine the reliability of the final results. Making the "picks" is important because most of the problems that come up in practical work are connected with the problem of what can be done with poor records. The lack of any definite criteria by which to judge what are good and usable reflections is at the bottom of the difficulty. Give the same set of records to several people to mark and they will probably come out with a variation in the number of reflections per record that are deemed usable. With good records the correct picks are obvious to all, but with poor records experience seems to be the only reliable guide as to what picks are reliable and what are merely born of imagination and desperation. Experience in marking records and seeing how the structures eventually check out is more important than training in physics or geology. Different types of equipment and shooting methods may produce records quite different in appearance, from the same territory, and the computer can do his best work with records of a type on which he has had considerable experience, and has learned the limitations and shortcomings as well as the virtues of the data with which he is working. Reflections may be picked for dips only, in which case the particular reflection picked is not recognizable with certainty on records from any other spread. For the purpose of computing dips it is necessary that the reflection be marked on a11 or nearly all of the strings of the records, as

Jan 1, 1940

By Carl Benedicks

IT is well known by every one who has had to deal with boiler tubes that these are often seriously affected by a sort of corrosion, occurring as a local pitting, that frequently causes a perforation of the tube in a rather short time. The characteristic appearance of this corrosion is shown in Fig. 1. A very similar corrosion occurs in condenser tubes (Fig. 2).1 A study of the microstructure or local chemical composition of the metal (iron; 70 :30 brass) fails to reveal any cause for this pitting. Of course one might possibly assume the starting point-to be some oxide particle, causing an electrolytic local action, but this in no way explains the continued corrosion, progressing even when the assumed oxide particle must have disappeared. By the excellent work done by the Corrosion Research Committee of the Institute of Metals, and communicated, in October, 1923, to the Institution of Engineers and Shipbuilders in Newcastle-on-tyne, stress was laid on the fact that a content of entangled air has a very obnoxious effect. In the following correspondence, Sir George Goodwin stated that "engineers have, for a long time past, regarded air as the big enemy to be fought against in all questions of corrosion"2 and Kenneth Fraser pointed out that the most vital point is "the avoidance or removal of possibly the chief cause of present day corrosion, i. e. entrapped air and gases brought out of solution."' In their reply, however, the authors state that they had "never for a moment believed that entangled air was responsible for the beginnings of corrosion, and express the opinion that the gradual liberation of air could not account for localized corrosion."4 On consulting the many textbooks on corrosion, as that

Jan 4, 1925

By Robert H. Hafner, Irvin R. Kramer, Stewart L. Toleman

IN his paper on the calculation of hardenability from chemical composition, Grossmann1 discussed the effect of most of the alloying elements used commercially. The purpose of the work reported in this paper was to determine the effect of several other elements on hardenability-arsenic, antimony, beryllium, cobalt, columbium, germanium, tellurium, tin, aluminum, and titanium-and to extend the range of composition of some of the elements studied by , Grossmann-chromium, copper, manganese, molybdenum, nickel and silicon. EXPERIMENTAL METHODS To determine the effect on hardenability, suitable amounts of the alloying elements were added to experimental heats and the hardenability determined by means of end-quenched hardenability specimens. The steels were melted in a high-frequency induction furnace with a basic crucible, using ingot iron as a base for some of the heats and S.A.E. 1015 for others. The alloying additions were made as ferroalloys or as metal, depending on the ' alloying element. Hundred-pound heats were split and poured into square, tapered, cast-iron ingot molds with hot tops. Aluminum was not used as a deoxidizer in most of the heats. The ingots were homogenized for 12 hr. at 1260°C. (2300°F.) , and forged into rounds of 1 ½ in. diameter. These bars were normalized twice from 840°C. (1550°F.) before machining into Jominy bars. The composition of the steels was deter- [ ] mined in most cases by samples taken from the end-quench hardenability specimen. As suggested by crafts,2acid-soluble

Jan 1, 1943

Established as a Division November 17, 1948 R Schuhmann, Jr, Chairman A E Lee, Jr, Past Chairman R C Cole, Chairman-Elect H W St Clair, VIce-Chairman, '61 , Vice-Chairman, '62 Paul Queneau, Vice-Chairman, '63 T D Jones, Treasurer R W Shearman, Secretary AIME, 29 West 39th Street New York 18, N Y

Jan 1, 1960

By W. G. Wender

The North Central Texas district, as known to the oil fraternity, is the area producing from sands and limes of Pennsylvanian age, roughly embracing the territory lying between Fort Worth and Abilene in an east-west line, and between the Red River and the Llano Mountains in a north-south line. The history of oil development in North Central Texas during the year 1927 is briefly reviewed in the following paragraphs. Brown County New discoveries and development in Brown County centered mainly around the Fry pool, located in the west central portion of the county. Important discoveries for the year were: Shoupe No. 1 John Byler, discovery well of the Byler pool, located 2 miles south of the Fry pool which camc in early in February, 1927, at 1262 ft. for 90 bbl. in the Fry sand of upper Strawn (Pennsylvanian) age. Rosenfield No. 1 P. Davis, discovery well of the Smith-Ellis pool located 1 1/2 miles northeast of the Fry pool, came in March 7, in the Fry sand from 1277 to 1279 ft. for 30 bbl. initial. Pandem Oil Corpn. No. 1 Mrs. T. Hutton, located 1 mile east of the Smith-Ellis pool, came in in December in the Fry sand from 1119 to 1130 ft. for 45 barrels. The Fry pool passed its daily production peak of 25,000 bbl. during the first part of June, and declined to a daily production of 5100 hhl. by the close of the year. The oil recovery from the Fry pool up to Jan. 1, 1928, slightly exceeded 4,000,000 bbl., averaging 4700 bbl. to the acre. over the entire pool. The Smith-Ellis pool passed its daily production peak of 5300 bbl. in Octohcr, 1927, and dropped to 3600 bbl. by the close of the year. The possibilities of the Byler pool will be unknown until the area is fully drilled up. In the Blake pool, production passed 2,500,-000 bbl. for the year. The per acre recovery in this pool up to lkc. 31, averaged slightly over 5000 barrels.

Jan 1, 1928

[ ]

Jan 1, 1938

By Matthew J. Hrebar

SINCE the first installation in 1936, the use of rubber-tired equipment for secondary mine haulage has increased rapidly. From August 1936 to January 1944, approximately 750 rubber-tired units were placed in operation. Of these, 650 units were installed after January 1940. During the year 1941, it per cent of the mobile loaded bituminous tonnage was hauled by rubber-tired equipment. This percentage increased to about 20 per cent during 1943. The first rubber-tired units were battery-powered tractor-trailer types. In the year 1938 the battery-powered self-contained car was introduced. In 1939, the cable-powered self-contained car made its appearance. These self-contained units are our modern "shuttle cars." By the end of 1941, approximately 15 per cent of the shuttle cars in operation were cable-powered. Installations made during 1942 and 1943 increased the proportion of cable-powered cars to about 40 per cent of the total number of shuttle cars in use. There is a marked trend toward cable-powered cars, although one need not make many trips to mines where both types are used to discover that opinions are highly controversial as to the relative advantages and field of use of each type. It is natural for mining engineers in the coal-mining industry to have diversified opinions regarding the use and application of coal-mining machinery. Coal mining is not a standardized industry; natural conditions vary from mine to mine. However, it is surprising how many operations in scattered fields arrive at the same conclusions and adopt similar methods. This happens not so much through cooperation and exchange of ideas as through hard, costly experimentation, involving months of low production and relatively high costs. What then, are the reasons for increased use of cable cars? Could it be that present scarcity of materials is forcing their use? True, battery cars require considerably more auxiliary equipment, but during 1942 it was no more difficult to obtain than shuttle-car cable. Furthermore, the trend toward cable cars started before curtailments on mining equipment took effect. Undoubtedly, cable-reel shuttle cars were introduced to produce coal at a lower cost by simplifying trackless mining through the elimination of auxiliary equipment, and by reducing the first cost on equipment. The theory of cable-powered shuttle cars is well based, as can be proved by successful operations. Many operators have weighed the advantages and disadvantages of each type carefully before choosing the type most suitable to their operation. Others have taken much for granted and accepted one or the other without much thought. At many small operations, low first cost is apt to be the deciding factor. One large company, with considerable experience in the use of battery locomotives, preferred to use cable cars even though it was neces¬sary to reduce the section voltage from

Jan 1, 1944

By M. D. Everell

A study has been made of the relationships between grinding selection functions and physical properties of rocks, particularly the failure loads of irregular particles and the compressive and tensile strengths of large regular specimens. The rocks used were limestones of various structures and impurity contents, a carbonatite, and a high-purity crystallized calcite. The selection functions were obtained from carefully performed grinding experiments on selected narrow size ranges in various grinding machines-a laboratory batch ball mill, a Hard grove grindability machine, and a mill of the type suggested by Yang, Mempel, and Fuerstenau. The specific rates of breakage during milling and the failure loads of irregular specimens correlated well for the rocks studied. The testing of irregular particles is suggested as a means of predicting the behavior of commercial mills.

Jan 1, 1973

By Kenneth L. Adams

10.3-1. Introduction. Equipment replacement or maintenance is of major concern to every company today. It can be the difference between an efficient and profitable operation or an inefficient and struggling one. Mining equipment, as everyone knows, will not last forever. Some equipment becomes obsolete before it wears out while some may be doing its intended job, yet not economically. It is a major problem for management to make the decision as to whether a piece of equipment should be repaired or replaced. There are numerous approaches to this problem; using formulas, charts, and graphs. These would be very good if all conditions were stable. Since conditions and requirements are constantly changing, an accurate observation cannot be derived from a set formula. A formula does, however, serve as a reminder to include most of the items that should be considered when evaluating old and new equipment. In the field of mining there are several questions which enter into the reasoning that are difficult to put into an equation. Some of these are: 1. Will the present equipment produce the required output of the mine, or an increase if necessary? 2. Are reserves adequate to support the purchase of new equipment? 3. Can the old equipment be repaired to efficiently continue the mining operation? 4. What is the stability of future markets for the product? Depreciation rate, or the write-off life, is a factor that can directly effect decisions on replacement. If the initial life expectancy is too long and the price of equipment is not written off when discarded, then the original investment has not been recovered. If the write-off time is too short, then the equipment is written off before replacement is even considered. In this case, the depreciation accrual is usually used to finance some other phase of the operation. In view of the increasing prices, the amount of depreciation fund is generally too small for much incentive to replace an older unit

Jan 1, 1968

By R. E. Hucko

Introduction The principal thrust of the US Department of Energy (DOE) coal preparation R&D program is to develop technology to reduce ash and sulfur content of US coals to levels where the resultant product can be formulated into a high quality solid or slurry fuel that could replace oil or natural gas in both new and retrofit applications. The coal preparation program is implemented by the Pittsburgh Energy Technology Center (PETC) and is conducted both in house and by a cross section of industrial organizations, universities, and national laboratories. Research is subdivided into three areas - coal characterization, beneficiation, and ancillary unit operations.

Jan 1, 1985

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York LOUIS D. HUNTOON, Chairman. ARTHUR S. DWIGHT, Vice-Chairman. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. E. MALTBY SHIPP, Treasurer. GEORGE F. KUNZ, W. DE L. BENEDICT. Boston ROBERT H. RICHARDS, Chairman. ALBERT SAUVEUR, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. TIMOTHY W. SPRAGUE, HENRY A. WENTWORTH.

Jan 2, 1914

THE CHAIRMAN (H. W. MORSE, Los Angeles, Cal.).-I would like to open this meeting for a little while to the general subject of leaching. We ought not to hold back if we have any new schemes for the future. I know that those of us who are tangled up with this lei thing work will appreciate any suggestions that will make us work harder and, scheme, harder to pull through these past difficulties on leaching. F. S. SCHIMERKA, Clifton, Ariz.-Under the direction of J. W. Bennie, General Manager of the Shannon Copper Co., Clifton, Ariz., 'it has been my valued privilege to cooperate in the elaboration of a hydrometallurgical process aiming at the recovery of copper in mill tailing resulting from a gravity concentration of a low-grade semi-oxidized sulphide ore occurring in a porphyritic gangue. The experimental work which has been carried on with a 25-ton plant is completed, and the company is building at present a leaching plant on a larger scale, the first unit consisting of a 150-ton roasting furnace and accessories for leaching the calcine.

Jan 12, 1916

By D. C. Buffum, L. D. Jaffee

THAT the path of brittle fracture in temper brit-tle steel differs from the path in unembrittled steel has been known for some years1 More recently it has been recognized that alloy steels, at least, display two forms of temper brittleness1 which may be called upper-nose and lower-nose. No experimental evidence has been published, however, to show that the two forms can be distinguished by simple inspection of brittle fractures. Fig. 1 is a photograph of the fractured surface of a V-notch Charpy specimen of SAE 3140 steel in which temper brittleness developed during heat treatment in the lower-nose temperature range.' The steel was austenitized 1 hr at 900°, tempered 1 hr at 675", and embrittled 48 hr at 500°C, with water-quenching after each treatment. The temperature of transition from ductile to brittle fracture in the Charpy test was + 2°C (criterion of transition: 100 pet fibrous). The hardness was Re 25; the austenite grain size ASTM 8. This specimen was broken at 150°C in the standard Charpy test and absorbed 6.6 ft-lb; its fracture was rated 0 pet fibrous. Fig. 1 shows that the fracture appeared rough to the naked eye. At the side of the specimen away from the notch (the side which was in compression during the test), the surface as a whole deviated sharply from a plane. At higher magnification, X60, the surface gave

Jan 1, 1959

By L. Russell Van Wert

DURING an investigation in which the solubility relations of the phases in Muntz metal (60 per cent. copper, 40 per cent. zinc) were under study, certain phenomena that had no immediate connection with the main problem were observed, which were thought sufficiently interesting to study further. Because of lack of time, only a preliminary survey was made of two of these; namely, the cleavage structure developed under certain conditions in a 60:40 brass and abnormal grain growth in this alloy. CLEAVAGE STRUCTURE IN HEAT-TREATED MUNTZ METAL Carpenter noted many years ago that cold-working a brass of the Muntz metal type, which had been quenched previously from within the beta field, results in a partial breakdown of the supersaturated beta solution and the precipitation of the solute (the alpha solution) in the cleavage planes of the beta grains. This manner of rejection of a solute from a metastable solid solution is not peculiar to this particular alloy, for among others, it occurs in the cold-working of certain austenitic steels; for example, the austenitic nickel steels. In these ferrous alloys, cold deformation produces a partial decomposition of the austenite, with the formation of martensitic "needles" and zigzags in the austenitic poly-hedra. It is interesting to note that while the two solid solutions-austenite and quenched Muntz metal- are metastable and in their mode of decomposition behave quite alike when deformed in the cold, the metastability of each results from a different cause; viz., that of the austenite from the fact that it is a supercooled solution (its solvent, gamma iron, at ordinary temperatures is below its normal stable range) whereas the metastability of the quenched Muntz metal is the result of supersaturation.

Jan 1, 1929

By William P. Shinn

Jan 1, 1880

By R. W. Raymond

I DESIRE to call the attention of the Institute briefly, and by no means in the way of an exhaustive description, to the interesting developments recently made on the east bank of the Hudson River, in the mining of spathic iron ores. The mines to which I refer are those of the Hudson River Spathic Iron Ore Company, situated at Oakhill on Hudson, Columbia County, N. Y., five or six miles from the city of Hudson, and opposite the town of Catskill. The ore occurs in beds, constituting apparently members of the stratified series of rocks on that side of the river, coursing nearly north and south, parallel with the river, and dipping east. The principal outcrops are presented in a range of low hills, about one mile from the river, along the crest, on the western face of which the stratum of spathic ore is more or less exposed. The length of the line in this range, along which, at various openings the ore has been discovered in profitable quantity, is about two miles. To the northward, the hills are somewhat higher, and the stratification may possibly be disturbed, though the rapid examination of the locality which I made in November last did not, include any determination of this