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Jan 1, 1952

By William E. Ford, Edward Salisbury Dana

I. Sul~harsenites, Sulphantimonites, etc. In these sulpho-salts, as further explained on p. 320, sulphur takes the place of the oxygen in the commoner and better understood oxygen acids (as carbonic acid, H2COs, sulphuric acid, H4S04, phosphoric acid, H3P04, etc.). The species included are salts of the sulpho-acids of trivalent arsenic, antimony and bismuth. The most important acids are the ortho-acids,

Jan 1, 1922

By Raymond B. Ladoo, C. A. Stokes

This paper summarizes the economic problems of the industrial mineral industries which are essentially different from those of the metals and the fuels. Failure to understand and evaluate such factors as markets, place value, and substitutions of one mineral for another may be disastrous. The engineer should be as responsible for profitable operation as he is for technical efficiency. The Raw Materials Survey of Portland, Oregon, is described.

Jan 2, 1950

By Lennart Bergstedt, Olov Fägremo

Boliden Metall Aktiebolag, the prime base metal mining company of Sweden, treats some 10-10.9 t/y (11-12 stpy) of sulphide ore in nine concentrators. During the years considerable effort has been devoted to the development of all phases of the technology of ore prospecting, mining, milling, smelting and refining. This has been necessary due to the complex and low grade ores. The autogenous grinding technique was first studied within the company as early as 1945. Basic test work commenced during the early fifties, whereby the merits of pebble grinding could be evaluated.

Jan 2, 1978

By Thomas L. Kesler

Lithium raw materials usable with present technology consist of pegmatite ore and shallow evaporite brine. Deposits of these materials occur in many parts of the world. Those advantageously located supply the present lithium industry. Less favorably located deposits will come into production as markets expand and present sources are depleted. In this discussion, materials listed as reserves include fully explored and partly explored deposits. For those closely drilled and assayed, the data provide measurements rather than estimates, and such reserve tonnages are "proved." For deposits partly explored, the data support reserve estimates of "probable" tonnages. Materials lacking exploratory data are classed as resources, and their "possible" tonnages are inferred mostly from indirect evidence and are essentially objectives for exploration. All figures for pegmatite ore apply to total materials in the ground.

Jan 1, 1979

By S. T. Wellman

The gradual change within the Iast few years from wrought-iron to steel for many purposes, notably for rails, plates, beams and other structural shapes, has brought the desirability and possibility of casting and rolling the steel in very large masses as compared with the

Jan 1, 1891

By F. Milton Lewis, Roshan B. Bhappu, James L. Coburn

FOREWORD-To comminute is to pulverize, but, in mining technology, "comminution" includes all the multiple crushing and grinding operations on ore, rocks, coal, and certain other bulk materials. The primary objective of this two-part article series is to provide the reader with basic information and guidelines for designing comminution systems. Part One is confined to ore processing operations, where size reduction is required to liberate the valuable minerals so that they may be concentrated and recovered. Part Two will illustrate various design techniques through practical examples.

Jan 9, 1976

Eckley B. Coxe, Drifton, Pa.: Anthracite coal differs from other fuels in its greater solidity. It does not burn like coke or wood, or like bituminous and coking coals, which become more or less spongy when heated, so that combustion can take place to some

Jan 1, 1892

By William Kent

During the discussions at the Philadelphia meeting in February last;) several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting, the discussion of the " practical value of chemical analyses" has been continued at some length in 'the columns of the Iron Age.

Jan 1, 1882

By William Kent

DURING the discussions at the Philadelphia meeting in February last, † several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting,. the discussion of the "practical value of chemical analyses" has been continued at some length in the columns of the Iron Age. †Transactions, vol. ix, p. 529.

Jan 1, 1882

By Kraig W. Grubaugh, Lee W. Saperstein

Rapid growth rate of surface mining for coal has caused many states to increase the rigor and complexity of their surface mining codes. The promulgation of federal surface mining standards may cause those states containing federal land to amend their codes also. Presented is an up-to-date review of these codes with tabular summaries that divide the codes into operative functions. These summaries will be of use to new operators, multiple-state operators, and state officials. Suggestions are made for industrial efforts to present workable and acceptable amendments to these codes.

Jan 1, 1978

By Frederick N. Clark

These tests were made under the writer's supervision in the mining and metallurgical laboratories of the Massachusetts Institute of Technology, in the winter of 1888-89, by Mr. Robert C. Williams, of Marquette, Mich., assisted by Mr. J. B. Seager, of the

Jan 1, 1890

NEW MEMBERS. The following list comprises the names of those persons who became members during the month of November, 1913: Members. AGNEW, JOHN L., Gent Supt Copper Cliff, Ont., Canada. BAILEY, FRANK C, Mine Mgr 2003 IV. Snito Ave., Spokane, Wash. BATEMAN, ALAN M., Min. Geol.,Care L. C. Graton, Geological Museum, Cambridge,Mass. BERRYHILL, JAMES G.,Atty.-at-law and Mining Investor, Equitable Bldg., Des Moines, Ia. CARTLIDGE, OSCAR, Mgr. State Mine Rescue Station, 452 W. South Grand Ave.. Springfield. Ill.

Jan 12, 1913

By R. L. Loofbourow

The objectives of this report are (1) to indicate what is known of natural rock temperatures as deep as 5000 ft below the surface, (2) to indicate methods for estimating such temperatures in localities where directly measured temperatures are un- available, and (3) to outline as far as possible, areas in the 48 states within which rock temperatures are likely to be low and high. The usual object of temperature measurements in deep mines and wells is to learn the temperature of air or another circulating medium. This usually differs significantly from the undisturbed rock temperature. The subject is complicated further by the variety of the thermal properties and structures of rock masses, the migration of fluids within them, the diversity of the history of rock masses and of the processes which have been at work on them during that history.

Jan 1, 1966

By W. H. Chang

The phase identification results on several Mg-base alloys are presented. These results have been correlated with strength data and microstructural studies to indicate that carbide dispersion may contribute significantly to raising the recrystallization temperature and strength of Mo alloys. Evidence is presented to show that the degree of carbide dispersion, and hence the extent of strengthening, is governed by the "metal/carbon" ratio which, in turn, depends on both the carbon content and the presence of stable -carbide-forming alloying elements. IN recent years, Mo-base alloys containing small additions of C, Ti, and/or Zr have been developed, which exhibit much higher recrystallization temperature and strength than those of unalloyed Mo. The superiority of these alloys undoubtedly results from simultaneous operation of more than one strengthening mechanism. In the present paper, the strengthening effect of carbide dispersion will be discussed. Although the role of carbide dispersion is being increasingly recognized, the nature of the carbides has, to the author's knowledge, not been well es- tablished. In Table I are presented some of the phase identification results on representative Mo alloys. These results have been obtained by X-ray diffraction of residues electrolytically extracted from an ethyl alcohol solution containing 7 pct HC1.

Jan 1, 1961

By John H. Stewart, Daniel R. Shawe

Major transverse structural zones in the western U.S. such as the Lewis and Clark line, Walker Lane, Texas lineament, and Colorado mineral belt, have localized important mineral districts. In Nevada and Utah the alinement of Cretaceous and Tertiary mineral deposits, such as in the Pioche, Eureka, Manhattan, and other mineral belts, may be related to similar tectonic features. All the mineral belts in Nevada and Utah have produced precious and base metals and tungsten; the Manhattan belt in addition has produced magnesite and brucite; and the Pioche belt, uranium, fluorspar, and alunite. Specific types of ore deposits seem related spatially to major belts of the Paleozoic Cordilleran geosyncline and compositionally to the intrusive bodies with which they are associated.

Jan 1, 1977

By H. L. James

THIS paper presents the results and analysis of field trials of various magnetic instruments over anomalies ranging from 20 to 5000 gammas of vertical intensity. The following instruments were used: Askania vertical magnetometer, Wolfson vertical magnetometer (model M-I), Hotchkiss Superdips (used both parallel to and normal to the magnetic meridian, with several settings of the "sigma" angle), Lake Superior dip needle, and the dipping circle for measurements of inclination. The change in inclination over the measured anomalies ranged up to 4°; this caused pronounced changes in sensitivity of the Hotchkiss Superdip oriented parallel to the magnetic meridian. The variable sensitivity not only gives apparent displacement of crests of anomalies, particularly at high sensitivities, but also makes the data difficult or impossible to use in preparation of iso-anomaly maps. This weakness in field performance of the Superdip is shown to be eliminated by orienting the instrument normal to the magnetic meridian and measuring vertical intensity only, which in the latitude of upper Michigan is equal to 97 pct of the total intensity. The dip needle is seen to be relatively ineffectual for location of anomalies of less than 400 gammas.

Jan 1, 1947

By AIME AIME

The Following List Comprises The Names Of Those Persons Elected As Members Or Associates, Who Accepted Election During May And June, 1908 MEMBERS. William H. Bainbridge Searchlight, Nev. William N. Brown, . Gainesville, Va. Willis S. Caypless, .. . . . . Denver, Colo. William B. Clark, Baltimore, Md.

Jan 7, 1908

By John Birkinbine

THE favor with which the members of the Institute received Mr. Fernow's paper upon the use of charbon roux in the manufacture of iron has encouraged me to present this paper, in the hope of having the discussion upon the manufacture and use of the oldest and undoubtedly the best fuel for producing pig iron continued. Owing to the advances made in employing anthracite coal, bituminous coal, or coke, or mixtures of them, we are apt to forget how much of our present development is due to the pioneers in iron manufacture and the fuel which they employed in the production of pig iron. In Mr. Swank's last compilation of the iron and steel works of the United States, the furnace capacity of the country is given as 5,868,000 tons, of which 1,000,000 tons can be made in the 264 charcoal furnaces. In other words, over one-third of the furnaces now in existence use charcoal for fuel, and produce more than one-sixth of the iron made. If to this is added the 130,000 tons of blooms and billets turned out by the 122 forges and bloomaries, the importance of the charcoal industries will be appreciated.

Jan 1, 1879

By Charles R. Keyes

PAGE I. Introductory............ 140 II. Location and History...........140 III. Surface-Relief of the District....... 141 IV. General GeoloGic Features........ 142 1. Main Relationships and Map....... 142 2. Résumé of Geologic History..143 V. Geologic Formations Represented...144 1. Broader Considerations......... 144 2. Geologic Section.......... 145 3. Nomenclature.......... 146 4. El Pasan Limestones..146 5. Santa Rita Limestone.... 146 6. Silver Shales........... 147 7. Bella Shales........... 147 8. Berenda Limestone..147 9. Grande Limestone... 148 10. Lake Valley Limestone........ 148 11. Sierra Limestone.......... 149 VI. Unconformities........... 149 VII. Geologic Structure.......... 150 1. Main Characteristics......... 150 2. Folding........... 1.50 3. Faultings........... 150 4. Relations of the Eruptives...153 VIII. Geologic Relations OF the Ore-Bodies...... 154 1. Governing Factom......... 154 2. Position.......... 154 3. Relations to Foldings...155 4. Relations to Lines of Dislocation... 15.5 5. Relations to Present Surface.Relief..156 6. Relations to Eruptive Rocks...157 7. Relations to Lithologic Nature of the Rocks.... 158 IX. MINERALOGIC CHARACTER OF THE ORES...... 158 X. Origin of the Ore.Deposits..159 1. General Statement......... 159 2. Original Source of the 0re.Materials...160 3. Contact-Metamorphism of the Region... 161 4. Process of 0re.Concentration..162 5. Lowering of Ground-Water Level..162 6. Formation of Cerargyritic Ores...163 XI. Recapitulation........... 168

Jan 1, 1909