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By J. F. Myers, F. M. Lewis

The paper reports the development of a large, slow speed ball mill closed circuited with a hydroscillator. This increased grinding efficiency 28 pct over conventional units.

Jan 6, 1950

By F. Newton Parks

SOUND management organization is as essential to a mining operation as sound mining practices, exploration methods, concentration processes, or marketing methods. In fact, if a mining company is well organized, with the right people in the right management positions, it can be reasonably assured of the adequacy of its operating practices. Management problems in mining are unique, but certain principles of organization are universal. These principles should be used as ground rules in mining as they are in other industries.

Jan 5, 1958

By W. D. Roberts

INTERGRANULAR corrosion of metals and alloys has been extensively investigated and the current conclusions are summarized in the Symposium on Stress-Corrosion Cracking of Metals.' It appears, however, that the relative importance of the various factors involved in the mechanism is still obscure. Several recent, independent studies, in combination with available X ray data op preferred orientation, indicate that there may be a direct correlation between relative orientation of contiguous grains and susceptibility to intergranular corrosion. The object of the present note is to show the nature

Jan 1, 1951

By C. A. Mezger

These districts are limited approximately on the north by the railroad from Salisbury to Ashville, and comprises the counties of Alexander, Catawba, Burke, Rutherford, McDowell, Cleveland, Lincoln, Polk and Henderson in North Carolina, and Greenville, Spartanburg, Union and York in South Carolina. The occurrence of monazite at Amelia Court House, in Virginia, belongs evidently to the same geological system, as its distance from the Alleghenies corresponds with that of the above-mentioned districts, and all the stratification runs parallel with those mountains.

Jan 1, 1896

CENTRAL AMERICANIZATION COMMITTEE Chairman, MRS. C. C. BURGER This committee reports progress in drawing up circulars on the. subject of Americanization, to be sent to all the branches of the W. A. A. I. M. E. It is greatly to be desired that all our members should interest themselves personally in work that can be done among the women and children in the mining districts in the way of Americanizing those of foreign birth or extraction; so much can be accomplished by individual interest and sympathy.

Jan 11, 1918

By W. C. Lacy

A WIDE variety of metalliferous deposits in Peru shows a close and consistent relationship to intrusive and extrusive igneous rocks. This relation- ship furnishes a clue to the composition of ore-bearing fluids and to the timing in separation of these fluids from differentiation magma. Conclusions presented here are based on ten years' study of a large number of metalliferous deposits in Peru. The most important of these areas are shown in Fig. 1.

Jan 5, 1957

Robert Annan is an Englishman who started his brilliant mining career in Arizona, yet achieved the pinnacle of success in his native land when he became chairman of The Consolidated Gold Fields of South Africa. This story of his life, prepared in collaboration with the late Henry Carlisle, continues this fascinating biographical series of important personalities in the mining industry.

Jan 12, 1964

Executive A R LEDUC, Chairman ARTHUR S DWIGHT R V NORRIS EDWIN LUDLOW E L DEGOLYER Membership J V W REYNDERS, Chairman E L DEGOLYER R M RAYMOND EDGAR RICKARD W Y WESTERVELT Finance WALTER H ALDRIDGE, Chairman GALEN H CLEVENGER J V W REYNDERS Library Chairman JOHN H JANEWAY GEORGE C STONES ROBERT LINTON ALEXANDER C HUMPHRLYS, - BRADLEY STOUGHTON

Jan 1, 1923

By J. Nolan, B. Ande’n, E. Lindgren

Field testing was conducted at the Strassa Iron Ore Processing Plant to evaluate high-gradient magnetic recovery of iron from the plant's tailings. The installation is the first commercial application of the Sala Continuous High-Gradient Magnetic Separator (HGMS) Model 480 Carousel. The objectives of the five-month testing program included optimization of the operating parameters using SSDEVOP techniques to maximize iron recovery, along with establishing a long-term operating history for the SALA 480 HGMS Carousel. The effectiveness of the optimization procedure, the net benefit in term of iron recovery, and equipment performance are discussed in the paper.

Jan 1, 1983

By Nancy S. Brodsky

A specimen of Westerly granite was cyclically loaded to near failure at 50 MPa confining pressure. Holographic interferometry provided detailed measurements of localized surface deformations during loading and unloading. The data are consistent with deformation occurring primarily elastically at low differential stress; in conjunction with one incipient fault zone between approximately 350 and 520 MPa differential stress; and in conjunction with a second incipient fault zone above 580 MPa and/or during creep. During unloading only one fault zone, that which is active at the intermediate stress levels during loading, is seen to recede.

Jan 1, 1984

Jan 1, 1941

By John S. Alexander

The typical block coal of the Brazil (Indiana) District differs in chemical composition but little from the coking coals of Western Pennsylvania. The physical difference, however, is quite marked; the latter has a cuboid structure made up of bituminous particles lying against each other, so that under the action of heat fusion throughout the mass readily takes place, while block coal is formed of alternate layers of rich bituminous matter and a charcoal-like substance, which is not only very slow of combustion, but so retards the transmission of heat that agglutination is prevented, and the coal burns away layer by layer, retaining its form until consumed. This property permits the use of raw block coal in the furnace but theo-

Surface mine operators often gamble that the savings gained from elimination of haul-road subbase preparation will offset any potential loss in production due to deteriorating roads. According to the authors of a manual on haul-road construction, this practice yields results that are almost always undesirable. The lack of suitable weight-bearing material under the road surface permits extensive rutting, sinkage, and overall deterioration of the roadway, and a great deal of maintenance work will be needed to keep the road usable. In addition, say Walter W. Kaufman of Skelly and Loy, and James C. Ault, USBM Pittsburgh Mining and Safety Research Center, adverse road conditions pose a serious threat to vehicular controllability and create unsafe haulage road segments.

Jan 3, 1978

It appears that Utah is about to add another mining district to its already impressive roster. This time it is the Great Salt Lake, whose high-mineral content waters are being subjected to intensive study aimed toward the recovery of potassium, magnesium and lithium compounds by solar evaporation techniques. Among the firms conducting such experiments is Lithium Corporation of America, which, in a joint venture with West Germany's Salzdetfurth A.G., is operating evaporating ponds and running engineering tests at a site near Little Mountain, about ten miles west of Ogden. Here, on the clay flats along the northern portion of the lake, LCA holds leases and options totalling about 55,000 acres in the Bear River Basin.

Jan 7, 1966

By Brian W. Mackenzie

Since mineral economics is often coupled with mining engineering in the solution of mineral industry problems, it is important that the principles of this science be a part of the mining engineer's education. Essentially, mineral economics is the application of economic principles to analysis of the multistage process by which minerals are converted from geologic resources to marketable products. In some instances, it may require only the analysis of case studies from a well- developed economics core. In others, however, it requires special skills, because some aspects of the mineral conversion process--such as mineral occurrence, exploration investment and depletion-have no complete parallel in general economics. The mining engineer has been an important contributor to the analysis of mineral economics problems because of his special knowledge of the mineral industry.

Jan 1, 1971

By Donald A. Dahlstrom

Stronger Than Armies This editorial by Dr. Dahlstrom is based on his acceptance speech of the 1976 Robert H. Richards Award-Ed. Many public figures are saying that the United States is facing the most critical period in its history, and many of us would agree. But people have always been saying this, and all of them were right. They were right two centuries ago when it took a revolution to give birth to the Republic; and they were right during our Civil War, Pearl Harbor, the Great Depression, etc.

Jan 6, 1976

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

By Immo H. Redeker

North Carolina is the leading state in the US in lithium mineral production. Spodumene is mined in open pits and concentrated by flotation by the two companies, Lithium Corp. of America and Foote Mineral Co. North Carolina State University has a mineral research laboratoy in Asheville, N. C., with trained personnel, batch and pilot plant facilities to assist in the state's mineral development. The NCSU Minerals Research Laboratory assisted both lithium-producing companies with spodumene concentration problems and has lately worked closely with Lithium Corp. of America to develop the best flowsheet for spodumene and byproduct recovery. The concentration of North Carolina spodumene and byproducts from pegmatites is presented and illustrated with figures.

Jan 1, 1980

Jan 1, 1941