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Announcement is made that applications fir the Emmons Memorial Fellowship in Economic. Geology will be considered, and an incumbent appointed prior to the first of June. Applications should be sent to Professor J. F. Kemp of Columbia University not Intel: than May 15. . The holder of this fellowship receives an income of $1,000 and is expected to carry on an investigation in Economic Geology which will add a distinct contribution to the literature. The institution at which the study is pursued will be decided after conference with the members of the Committee of Awards. The character of the investigation will be decided after applications have been passed upon.

Jan 5, 1917

By Robert M. Cox

A roof bolting theory and structural model are presented which explain the success of most roof bolting installations as the creation of a competent roof bolt reinforced rock arch within the immediate roof rock overlying an underground opening. Likewise, the failure of some bolted mine roofs can be explained as a failure to create a structually competent rock arch by roof bolting.

Jan 1, 1975

By Claude H. P. Lupis, John F. Elliott

IN the recent past, extensive use has been made of the interaction coefficient in treating the thermody-namic behavior of components in solutions at dilute concentrations. The development of this concept by wagner1 and chipman2,3 is sufficiently well-known so that its elucidation here is not necessary. The present discussion is focused on the relationship between E and e. The usual forms of the coefficients are:

Jan 1, 1965

By A. E. Hall

The paper gives a general solution of ventilation net- works where densities play an important role and fans operating at different densities from branch densities are considered. Both the physics and computing techniques needed to deal with these networks are discussed.

Jan 1, 1977

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Jan 1, 1938

By Walter Kauenhowen

The production of crude oil in Germany during 1933 totaled about 1,669,521 bbl., a slight increase over the 1,608,558 bbl. produced in 1932. This is an extension of a yearly increase which has continued uninterruptedly since 1928. The 1933 increase in production is due chiefly to developments in the Nienhagen field. The production of the Wietze and Oberg fields remained rather stable, while the Oelheim-Eddesse and Volkenroda fields showed decreases. Nienhagen Field.—This field furnished about 61 per cent of the total German oil production in 1933. Most of the drilling activity centered the north district near the village of Nienhagen, where the trend of

Jan 1, 1934

By R. W. Raymond

By the death of Bergrath Prof. M. F. Gaetzschmann, which occurred on the 18th of February, in the 95th year of his age, at his lifelong home in Freiberg, Saxony, the Institute loses one of its earliest and most eminent honorary members, and the profession of mining and engineering one of its most influential and useful representatives,

Jan 1, 1896

By Oswald J. Heinrich

(Supplementary Paper.) IN conclusion of a series of deep exploration-borings with the diamond drill, I beg to submit the following statements, supplernentary to those in my former papers on this subject: Since my communications read at the St. Louis Meeting, in May last, I have finished two more borings, one terminating at the depth of 922 feet 7 inches, the other at the depth of 715 feet 6 inches. The results in regard to time and expenditure have been highly favorable and fully confirmatory of my opinion stated in previous

Jan 1, 1875

A recent study estimates that a 10% improvement in the performance of wire rope used on draglines could save the US coal industry $2 million annually in rope costs. In addition, such an improvement could boost annual coal production by allowing the industry's draglines to remove an extra 1.5 million m3 (2 million cu yd) of solid overburden each year. These findings, although admittedly preliminary, suggest the magnitude of benefits that can be derived from a well-planned wire rope maintenance program.

Jan 3, 1978

By Edgar C. Moxham

THE paper of Mr. W. H. Adams, read at the Cleveland Meeting, June, 1891 (Trans., xx., 196), on "The First Iron Blast-Furnaces in America," establishes the interesting fact that the earliest operations on this continent in the manufacture of pig-iron were based upon a deposit which, after many years of neglect, has now become again the object of active exploitation. In addition to the remarks of Messrs. Pechin and Raymond in discussions of the paper above cited,

Jan 1, 1893

By Ronald D. Hill, Roger C. Wilmoth

The neutralization of acid mine drainage is becoming a common practice in the eastern United States. Over 200 plants are now in operation. Lime is the neutralizing agent utilized in most treatment plants; however, limestone may have an economic and practical advantage. Current research efforts of the Federal Water Quality Administration, both inhouse and through grants, to develop and demonstrate the use of limestone are reported. In essence, a state-of-the-art review is presented.

Jan 1, 1972

In the four articles presented on the following pages, a panel of comminution experts offer readers the benefit of their experience with autogenous grinding and forecast some of the future developments to be expected in this fast-growing field. The articles are based on an AIME panel discussion in which the authors participated.

Jan 1, 1970

By Edward L. Clark, Garrett A. Muilenburg

THE first record of the discovery of iron ore in Missouri was Marquette's observation in 1673 of brown iron ore, or limonite, in the Mississippi River bluffs just north of the mouth of Apple Creek in southeastern Perry County. There is no record of any attempt to mine or smelt Missouri iron ores until 1815, when the Ashebran furnace was erected at the Stouts Creek shut-in near Arcadia, Iron County. Some limonite was treated in this furnace, the first iron furnace west of Ohio, but most of the ore was hematite from Shepherd Mountain and adjacent deposits. Eight years later, in 1823, the Perry furnace five miles north of Caledonia, Washington County, was constructed to smelt limonite ore. It

Jan 1, 1955

By D. Brabec

Previous studies have demonstrated the possibility of using aqua regia-extractable copper and zinc in plutonic rocks in exploration geochemistry. The present investigation compares this method of extraction with hydrofluoric-perchloric acid attack and bisulfate fusion in terms of precision and discrimination between high and low concentrations. Statistical treatment of data shows that the overall performance of the aqua regia method compares very favorably with other methods of attack.

Jan 1, 1972

By E. E. Malouf

Leaching is rapidly becoming an important adjunct to mining operations. A summary of various leaching operations is presented showing the role of these activities to the successful operation of the mining venture. The summary will include recent developments in dump, heap, and in situ leaching of copper and uranium ores. It will include a discussion on the expanding impact of industrial and academic research on leaching as a mining tool, showing the interplay of chemical kinetics and biogenic activity.

Jan 1, 1973

1. What Effect Has Sulfur Or Vanadium (In The Oil) On The Steel With Your Burner? 2. Also, what is the decibel rating on the floor when your burner is on? AUTHORS' REPLY 1. There is no effect. 2. The decibel rating is 98-99 decibels.

Jan 1, 1972

By William P. Blake

In southern Arizona and in Mexico the word caliche is in general use to denote a calcareous formation of considerable thickness and volume found a few inches, or a few feet, beneath the surface-soil, upon the broad, dry, gravelly plains and mesas. , In western South America the same name is applied to the beds of crude soda-niter (Chili saltpeter). While these deposits of South America and of Arizona are totally different in composition, and have nothing in common, except that both occur in

Jan 1, 1902

By L. E. Garner

Aggregate resources should be considered primary factors in urban development. Resource planning is essential because land values, previous construction, or zoning restrictions often preempt exploitation of aggregate deposits within an urban area. Sequential land use practices allow development of area prior to urban development population and aggregate consumption trends in Austin, TX, indicate that substantial quantities of reserves will be lost to future development. Aggregate materials are present in nearby areas. However, a comparison of transportation and reclamation costs indicates that reclaiming land after mineral extraction can be significantly cheaper than transporting materials longer distances.

Jan 1, 1982

Uranium, the object of a quarter billion-dollar search in the US during 1977, is a ubiquitous element rarely found in economic concentrations. It originates in magmas as a large tetravalent ion, the size of which restricts it from the crystal lattices of many rockforming minerals. Instead, according to United States Mineral Resources (US Geological Survey Professional Paper 820) as the magma crystallizes, a portion of the uranium is deposited as an intergranular film on rock forming minerals, enters accessory minerals, or forms its own minerals. The remaining uranium becomes concentrated in magmatic differentiates, where it forms minerals in pegmatites and veins.

Jan 10, 1978

By R. D. Coleman, A. E. McIlhinney, C. E. Capes

Problems of unstable operation in continuous balling circuits may be traced to the random generation of seed agglomerates. This has been verified during the continuous operation of a laboratory balling drum with internal recycle described previously by the authors. The cyclical behavior of a balling circuit was also investigated using a simple numerical computer model. Changes are suggested in the design of balling equipment to improve stability.

Jan 1, 1976