Search Documents

The manpower and time involved in primary blasthole stemming at Kennecott Copper Corp.'s Bingham Canyon mine have been reduced considerable through the use of a mobile stemming machine invented y three mine employees. The patented machine, developed 2% years ago at an estimated cost of $5000 for two units, is the brainchild of Thomas R. Carlson, mine plant superintendent; Alvin J. McIntosh, drilling and blasting engineer; and Jay K. Buehler, field repair general foreman. According to McIntosh, the machine has been well received by the mine employees, who have been relieved of the tedious task of hand shoveling drill cuttings into the blastholes. It is estimated that the stemming machine has saved the mine approximately $25,000 per year in overtime and regular labor costs.

Jan 12, 1976

By Richard K. Thorpe, Gordon D. Anderson, Merle E. Hanson, Ronald J. Shaffer

The propagation of pressurized fractures across a frictional interface is discussed, with emphasis on the case where an offset, or step, in the crack is produced. Theoretically, the steps can occur at regions of reduced shear strength along the interface. As a fracture is propagated toward a weak zone, extensional strain is concentrated at the edges of the zone where higher shear stresses can be sustained. Thus, when the fracture intersects the weak zone, it can be reinitiated at some small distance away on the opposite wall of the interface. The phenomenon has been studied through numerical modeling and laboratory experiments of the hydraulic fracturing process. Field observation of natural step cracks indicates that the mechanism is applicable to the genesis of jointing patterns in rock. Such features should not be confused, therefore, with steps caused by shear displacement of an interface.

Jan 1, 1982

By W. Spencer Hutchinson

THE purpose of this account is to introduce to other engineers and geologists who use photography a means of interpreting topographic and geologic structure with the stereoscope. Anyone who finds this of sufficient interest to read it at all must cut out the pictures shown and have a good look at them through the stereoscope; there is no other way to appreciate what is meant. Most of us have been disappointed by the flatness of mountain pictures and by the lack of perspective in photographs taken to illustrate topographic and geo- logic features. The use of the stereoscopic principle was suggested by the work of the photographic division of the Air service during the war. Photographs of the battle line, taken from air planes, were mounted for stereoscopic study, with most remarkable development of topography, penetration of camouflage and, by the matching of pictures with a time interval between, sure revelation of new work by the enemy. Thus, two views taken from a plane flying at 10,000 ft., both of the same terrain but from different points, are mounted in proper relation and put into the stereoscope. If the distance between the two positions of the camera was 200 ft., the observer then sees the topographic and military features as though his eyes were 200ft. instead of 235 in. apart.. The result is startling in its revelation of features that are flat and unintelligible when viewed by the unaided eye or in a single photograph. The technic of the work, as developed during the war, was quite complex and

Jan 1, 1921

By R. W. Shearman, F. Weston Starratt

A new center for mining and metallurgical research is developing at Sterling Forest, N. Y., under the auspices of Union Carbide Corp. Here is to be located the Union Carbide Nuclear and Ore Research Laboratories. In truth, history has repeated itself; the Sterling Forest area in the days of the Revolutionary War, and for many years thereafter, was the mining and metallurgical center of the US. For in these Ramapo hills along the New York-New Jersey border, iron ore was mined, pig lion was cast, and the weapons of war and the plowshares of peace were forged. Before embarking on an historical pilgrimage to yesteryear-a brief description of Sterling Forest. Located in Orange County, N. Y., near Tuxedo, immediately north of the New York-New Jersey State line, and just west of the Erie Railroad and the New York State Thruway, Sterling Forest is approximately 35 mi from New York City. Title was acquired in 1956 from the Harriman family by City Investing Co. Its President, Robert W. Dowling, has established himself as a city planner, having conceived such projects as Pittsburgh's Gateway Center and Philadelphia's Penn Center. A unique, self-contained community -is planned that will contain light industry and centers for research and engineering. Colonies of homes will be interspersed throughout the 20,000 acres of forest land, lakes, and rolling hills. Culture will not be neglected, for Sterling Forest will be the new home for the annual Empire State Music Festival The Sterling Forest Gardens, 125 acres of landscaped woodland and streams, will become the "world's largest permanent floral showplace" The Sterling Forest International Research Building was opened earlier this year, and designed to provide all facilities needed by small growth research companies. The first major company to acquire land to construct research buildings at Sterling Forest is Union Carbide. 1763 ... Discovery of iron ore In turning back the pages of history, a fascinating story can be told of special interest to the metallurgist, the mining engineer, and perhaps even the sociologist. For, where new communities are planned today, older communities had been born, matured, and died. In these hills had lived the. iron miners, the blacksmiths, the lumbermen, the masons, and the teamsters that had given America its start in heavy industry. This was the area where the forests were crisscrossed with many wood roads that brought logs to the charcoal pits, and iron ore to the furnaces. Men make history. Our story brings forth many names of men known as ironmasters, or as industrial leaders-Hasenclever, Faesch, Erskine, Townsend, Ryerson, Parrott, Cooper, Hewitt, Jay Cooke, and Harriman. The name Sterling is derived from a Scotch Lord, the Fifth Earl of Stirling (in its earlier spelling). Lord Stirling was one of seven Englishmen granted a patent of land in the Ramapo hills by Queen Anne in 1707, known as the Cheesecock Patent. He sent an agent, Cornelius Board, to America in 1730, with the express purpose of looking for copper deposits. While he found no copper in his travels up and down the Ramapo Valley, he did find iron ore in two localities: first, in the vicinity of what is now Ringwood, N. J.; second, five miles to the north. There he constructed a forge and furnace at the edge of a lake in 1736, naming the land Stirling Property, after his patron. In 1740, the Ogden family in Newark bought land from Board at Ringwood and began smelting of iron in 1741. The Ringwood story Soon, a genius in the person of Peter Hasenclever appeared on the scene. He was attracted by an advertisement in the New York Mercury for March 5, 1764, in which David Ogden of Newark offered

Jan 1, 1961

By RICHARD L. HUMPHREY

IT IS proper that there should be a brief accounting of the stewardship which was entrusted to the Joint Conference Committee by resolution adopted by the. Organizing Conference on June 4, 1920, in part as follows: RESOLVED, that it is the sense of this Organizing Conference that the Joint Conference Committee should be entrusted with making provision for putting the conclusions of this Conference of engineers into effect, etc. Pursuant to this authority, the Joint Conference, Committee has acted as an Ad-interim Committee has- prepared, a synopsis of the proceedings of the Organizing .Conference, has edited and published the Constitution and By-Laws adopted by this Conference, and. has issued an invitation to become Charter Members of The Federated, American Engineering Societies; to the list of organizations to whom invitations had been extended to attend 'the Organizing., Conference. The Committee in connection with this invitation offered to the extent of its ability, such assistance as might be-desired; and arranged in many cases for one or more of its members to be present when the matter of membership in The Federated American Engineering Societies was considered. . .

Jan 1, 1920

By James Norman, O. C. Ralston, John Dasher

MOST mineral products are used in the finely divided state, but some are sold in larger sizes. Coal, gravel, metallurgical fluorspar, phosphate rock, hematite, chromite, and other products are sold in sizes coarser than can be treated by many mineral-dressing methods. Gravity separation of coarser sizes by log washing and jigging is probably as ancient as any process now in use. The performance of jigs on a feed with sufficient difference in density of the minerals is excellent, but many families of minerals are too similar in density to be separated effectively by this method. The use of heavy suspensions of fine solids to separate coarse coal from bone and slate has been in use for some years. This separation by sink-and-float was limited until recently to light minerals. Development of galena and ferrosilicon as suspension media, by Minerals Beneficiation, Inc., at Mascot, Tenn., Pitcher, Okla., and Crosby, Minn., under patents granted during and since 1938, has permitted excellent results to be obtained on minerals of very similar densities up to 3.3. This process has been put in the hands of American Cyanamid Co. for exploitation, and further research now in progress may increase the density of suspension obtainable so that separations at a density of 4.0 may be practicable before this is published. The Huntington-Heberlein dense-medium process, developed in England, is also being commercialized in the United States by Sink and Float Corporation. Du Pont has developed a sink-and-float separation using halogenated hydrocarbons as parting liquids; at this writing, the method is used commercially only on coal but has been successful in the pilot plant on many other minerals using tetrabromethane at densities up to 2.95. While these processes were being developed to extend the range of separation by difference in density to the coarser sizes, the Bureau of Mines was engaged in developing a process that will extend the range of separation by difference in wettability up to 2-in. size. War work has pushed aside its further development indefinitely. The results are published here with the hope that some use may be suggested that will justify post-war development, and so that readers that may be able to make immediate use of the scheme may have the information. EARLIER WORK It has been known since the time of Herodotus (B.C. 484(?)-425) that water-repellent particles will adhere to sticky surfaces. That early historian reports the

Jan 1, 1942

By James Norman, O. C. Ralston, John Dasher

MOST mineral products are used in the finely divided state, but some are sold in larger sizes. Coal, gravel, metallurgical fluorspar, phosphate rock, hematite, chromite, and other products are sold in sizes coarser than can be treated by many mineral-dressing methods. Gravity separation of coarser sizes by log washing and jigging is probably as ancient as any process now in use. The performance of jigs on a feed with sufficient difference in density of the minerals is excellent, but many families of minerals are too similar in density to be separated effectively by this method. The use of heavy suspensions of fine solids to separate coarse coal from bone and slate has been in use for some years. This separation by sink-and-float was limited until recently to light minerals. Development of galena and ferrosilicon as suspension media, by Minerals Beneficiation, Inc., at Mascot, Tenn., Pitcher, Okla., and Crosby, Minn., under patents granted during and since 1938, has permitted excellent results to be obtained on minerals of very similar densities up to 3.3. This process has been put in the hands of American Cyanamid Co. for exploitation, and further research now in progress may increase the density of suspension obtainable so that separation, at a density of 4,0 may be practicable before this is published. The Huntington-Heberlein dense-medium process, developed in England, is also being commercialized in the United States by Sink and Float Corporation. Du Pont has developed a sink-and-float separation using halogenated hydrocarbons as parting liquids; at this writing, the method is used commercially only on coal but has been successful in the pilot plant on many other minerals using tetrabromethane at densities up to 2.95. While these processes were being developed to extend the range of separation by difference in density to the coarser sizes, the Bureau of Mines was engaged in developing a process that will extend the range of separation by difference in wettability up to 2-in, size. War work has pushed aside its further development indefinitely. The results are published here with the hope that some use may be suggested that will justify post-war development, and so that readers that may be able to make immediate use of the scheme may have the information. EARLIER WORK It has been known since the time of Herodotus (B.C. 484(?)-425) that water-repellent particles will adhere to sticky surfaces. That early historian reports the

Jan 1, 1942

By K. Stout, E. Van Eeckhout, L. Friel

Previous research at the Montana College of Mineral Science and Technology indicated that it is practical and economically feasible to place stiff back- fill in a cut-and-fill stope. This backfill would reduce wall closure and high stress buildup in pi1llars, thus alleviating rockburst potential. Three ;topes from the Sunshine Mine, of the Coeur d’Alene Mining District, were chosen for a test verification of this concept. Although the first stope was lever mined beyond the initial cut (for economic reasons), some vibrating wire stressmeter results were obtained and found to compare favorably with numerical predictions. Some other instrumentation devices were built and tested, but never installed .

Jan 1, 1984

By P. H. G. Durville

ANY metal which contains even a small percentage of aluminum possesses certain peculiarities of appearance and properties which are exhibited both when the metal is melted and after it solidifies. Pure aluminum, or an alloy containing a small proportion of aluminum, can be melted without flux-except for a layer of charcoal-because a film of aluminum oxide and metal forms at the surface of melted aluminum. Although very thin, this film is air-proof, and it prevents the metal underneath from oxidizing. This oxidized film does not move easily on account of its toughness and high surface tension. One very important point in connection with this process of still casting has not been strongly enough stressed, namely, that the same kind of surface film with the same peculiarities forms over the surface of all melted alloys that contain even a small proportion of aluminum. Experienced foundrymen know how desirable it is to cast aluminum under its "skin" or under the surface of the film which tends to remain still. In the case of red copper, when in fusion, the surface shows pure copper only. This is due to the fact that liquid copper constantly absorbs the copper oxide which forms on the surface. By closely examining melting copper the oxide can be seen dissolving in the bath, and going into solution just as pulverized sugar dissolves in water. When copper is cast in the open, either in wire bars or cakes, the surface of metal exposed to the air is covered by a film of black, oxide that cannot be absorbed by the metal.

Jan 1, 1927

By P. H. G., Durville

ANY metal which contains even a small percentage of aluminum possesses certain peculiarities of appearance and properties which are exhibited both when the metal is melted and after it solidifies. Pure aluminum, or an alloy containing a small proportion of aluminum, can be melted without flux-except for a layer of charcoal-because a film of aluminum oxide and metal forms at the surface of melted aluminum. Although very thin, this film is air-proof, and it prevents the metal underneath from oxidizing. This oxidized film does not move easily on account of its toughness and high surface tension. One very important point in connection with this process of still casting has not been strongly enough stressed, namely, that the same kind of surface film with the same peculiarities forms over the surface of all melted alloys that contain even a small proportion of aluminum. Experienced foundrymen know how desirable it is to cast aluminum under its "skin" or under the surface of the film which tends to remain still. In the case of red copper, when in fusion, the surface shows pure copper only. This' is due to the fact that liquid copper constantly absorbs the copper oxide which forms on the surface. By closely examining melting copper the oxide can be seen dissolving in the bath, and going into solution just as pulverized sugar dissolves in water. When copper is cast in the open, either in wire bars or cakes, the surface of metal exposed to the air is covered by a film of black oxide that cannot be absorbed by the metal.

Jan 1, 1927

By T. T. Read

FOR the second time the Mineral Industry Education Division opened the sessions at the Annual Meeting by gathering at the Engineering Woman's Club, Sunday at 3 p. in., and, in spite of the informality of the hour, with a good attendance of representative men in the educational field. The chairman of the Division, Thomas T. Read, after briefly reviewing some of the more significant events of the past year, introduced H. P. Hammond, professor of civil engineering, Brooklyn Polytechnic Institute, a leading figure in the project of the Engineers' Council for Professional Development for accrediting engineering schools. Prof. Hammond made it clear that the project is not to rate engineering schools but to accredit them; not to arrange them in order of excellence, but to segregate them into two groups, those that are entitled to recognition as genuine engineering schools, and those that are not. About thirty schools in the whole country will presumably fall into the latter class; they are typified by an unnamed institution where the teacher of mathematics bears the title of Professor of Civil Engineering and the man who teaches chemistry that of Professor of Chemical Engineering, and having no engineering instruction except some elementary surveying, but still claiming in its catalogue to be an engineering college. While everyone would like to avoid the necessity of accrediting engineering colleges, it cannot be avoided, since the University of the State of New York, and several other agencies, are already doing it. If it cannot be avoided it is best that it should be done by a qualified agency set up by the national engineering societies, so that the results may command respect and general acceptance. It is for this reason, and this alone, that the accrediting committee of the E. C. P. D. has been set up. It is now ready to begin its task, and during-the coming year it will accredit the schools in two of the seven geographical districts into which the country has been divided, beginning with New England and the Mid-Atlantic States.

Jan 1, 1935

By T. M. Yegulalp

This article summarizes some of the results of the continuing research activity at the Henry Krumb Schools of Mines, Columbia University, directed towards a better understanding of the stochastic behavior of slurry flows in underground coal-slurry pipeline systems. Fundamental ideas supported by field observations are presented and a Semi-Markov model of the slurry flows is developed. As a result of this formulation, behavior of combined slurry flows from N independent coal faces can be expressed in analytical form. The contents of a slurry surge tank receiving slurry flows with certain stochastic characteristics is investigated in a function of discharge pump characteristics and time.

Jan 1, 1983

By Richard J. Lund

Stock piling-and by that I mean well-organized stock piling on a substantial scale-is almost as old as the hills themselves. It was back in early Biblical times, as recounted in the Book of Genesis, that Joseph was charged by Pharaoh with the responsibility of stock piling food during the seven years of plenty to guard against the seven subsequent years of famine that were revealed by the Pharaoh's dream. And this same policy of storing up food or materials to provide for future anticipated emergencies can be traced repeatedly down through the ages. So our own efforts are anything but new. Our modern concept of stock piling-the purchase and storage of strategic materials to assure supplies needed in time of some future war- stems from our experience in World War I. In 1920, the War Department was charged by Congress with the responsibility of procuring all War Department supplies and mobilizing industry in the event of another war. During the two decades that followed there were many authoritative studies made of our deficient mineral problem, all of which pointed out the urgent necessity of stock piling certain strategic materials as a reserve against future war. One such study, made in 1925 through the combined efforts of the Mining and Metallurgical Society and the AIME, was done at the ex- press request of the War Department. Eight years later another more de-

Jan 1, 1949

By T. F. Witherbee

Discussion of Mr. Baker's paper, read at the Lake Superior Meeting, September, 1904. MR. T. F. WITHERBEE, Durango, Mexico (communication to the Secretary*) : Mr. Baker's paper is very instructive in that it shows how furnace-derangements sometimes originate from apparently slight causes. In 1896 a similar burning through of the lining occurred at the Mayville furnace of the Northwestern Iron Co., Mayville, Wis., in exactly 38 days from the time the furnace was blown in. At that time I attributed it to the fact that the bell was carried several inches to the front side of the furnace, the length of the versed side of the arc described by the lever, thus dumping a little more of the charge on the back side, which made the front side of the furnace-charge more open and consequently increased the circulation of the furnace gases through it. After reading Mr. Baker's description, I believe that possibly a little more ore was charged on the back side of the hopper, due to the fact that it was nearest to the elevator. This unequal charging, however, was unconsciously done, as the fillers were both honest and faithful. The illustration of the burned lining of Furnace No. 1, given in Fig. - of Mr. Baker's paper answers very well for the Mayville furnace. It shows that in both cases the destruction of the lining was largely due to faulty construction, in that there were no cooling-plates in the angle of the bosh and in one or two courses of brick above it, where I believe they are-more in demand than anywhere else in the furnace. The presence of these cooling-plates at the angle of the bosh would have obliged the current of the hot gases to turn the corner and would have prevented them from following the angle of the bosh com¬pletely through the lining and shell.

Mar 1, 1905

By AIME AIME

ON May 5, the Washington, D. C., Section, A.I.M.E., devoted its meeting to the many-sided and perplexing question of mineral stock-piling for peace. Opening the symposium, Harry J. Wolf, of the War Production Board, outlined the problem under six heads: (1) Technical. Mechanical, chemical, or metallurgical importance of specified materials, emergencies that might arise, relative scarcity, and critical value of stock piles during emergencies. (2) Economic. Cost to Government, influence of Government stocks on commercial relationships and markets, effect of availability of items as a con¬structive influence on industry, Administration policies now and during postwar period. (3) Legislative. Need for immediate legislative action, need for legislation on postwar conditions as well as on current requirements, a constructive basic policy to prevent political manipulation. (4) Military. Consideration of re¬quirements and supplies bearing on national safety and needed for manufacture of equipment, and adequate reserves of scarce materials for research or experimentation by military agencies. (5) International. Interests of the United Nations in contradistinction to those of the United States; effects of nonisolation policy on nature, location, and administration of stock piles. (6) Negative stock-piling. Question of United Nations' legislation to prevent stock-piling by Axis nations after the war and who shall purchase stock-pile materials and during what periods.

Jan 1, 1943

By Charles E. Packard

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

Jan 8, 1964

By John D. Morgan

THE tense international situation prevailing in the postwar period, and the outbreak of actual hostilities in Korea, directs attention to the status of United States reserves of strategic and critical materials for war. Geologists and mining and metallurgical engineers are particularly interested in this problem, since, with a few important exceptions, almost all of the materials on the official list of strategic and critical materials for stockpiling (see top of page) are metals and minerals.

Jan 3, 1951

By M. J. Miller

In modern mill design, a stockpile storage system for raw and/or semiprocessed ore has become almost indispensable. This paper discusses the benefits of such stockpile storage as well as the available types of belt conveyor stockpiling units. Alternative reclaiming arrangements for stockpiles are reviewed, and the advantages and disadvantages of each arrangement are discussed.

Jan 1, 1982

By L. O. Millard

Stockpiles in the minerals industries serve a wide variety of purposes. Usually they are for surge between stages of processing, for a dependable plant feed in anticipation of delays, or to provide for single or double shift mining in conjunction with round-the-clock milling. Often surge piles are necessary to insure a uniform feed to continuous process equipment where the material is received as an intermittent or variable flow. Extensive use is made of stockpiling for the primary purpose of blending. The significant fact about all stockpiling of bulk materials is that storing and reclaiming are two separate and distinct operations and they may present widely different problems in the selection of methods and tools.

Jan 10, 1959

By Nelson Severinghaus

Consolidated Quarries Corp. must conduct operations for an average sales price of $1.25 per ton, about the same price at which stone was sold 25 years ago when the dollar was worth twice what it is now. To maintain success in a competitive business, the company must solve the usual production problems, which will be discussed here in the order they occur in the flowsheet. Most crushed stone quarries must first remove soil and decomposed rock. Although seasons of lower sales sometimes release regular quarry excavating and haulage equipment for this purpose, overburden is often too extensive for this method to be used. In such cases, special equipment must be assigned or the job may be contracted. As many earthmoving contractors have heavy duty specialized equipment well suited to overburden removal, they should be seriously considered before the job is undertaken. Pockets of clay beneath peaks of hard stone sometimes defy mechanized removal. Pick and shovel laborers at this point might be supplanted by more ingenious use of pumps and water or some other mechanical means. Where overburden is extremely heavy or difficult to remove, underground mining must be considered.

Mar 1, 1956