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By John V. Beall

WHEN the atomic age broke suddenly upon the world in 1945 with all its terrible implications, predictions concerning the future of atomic energy were as numerous as columnists and often inflated. Today, some seven years since the explosion and probably ten since the Government took over development of nuclear energy, the impact on our way of living has been largely political (except of course for the thousands of people who have become employed in the AEC). Considering the world situation, weapons have come first naturally. But credible progress in the plow-share uses of nuclear energy-medicine, agriculture, power-can also be noted.

Jan 3, 1953

By Charles O. Thomson

When a wire rod of iron or of steel is immersed in a hot solution of common salt, allowed to remain long enough to bring the metal to the temperature of the brine, and withdrawn, the surface of the rod is irregularly covered with a deposit of crystals of salt. These crystals adhere to the cod with great firmnes, in consequence, doubtless, of a thin film of ferric hydrate, which is formed between them and the rod as the water dries off. The rod can now be reduced, by successive passes through a dic or draw-plate, without any

Jan 1, 1881

LOUIS Buchman walks down the hall of Kennecott's Chrysler Building offices as if he belonged there, but it wasn't his setting of choice. The West has become his home, that and the scene of operations is there. When he was a child his family came to the United States from Latvia and settled in Michigan's Upper Peninsula where he went to school and on to Michigan College of Mines. Graduating with B.S. and E.M. degrees, he headed west in 1907 to the mining camp of Ophir, in the state where he spent the bulk of his career - Utah.

Jan 5, 1953

By E. Northcott, F. N. Oberg

High-grade concentrates from Florida pebble phosphate deposits have long been recovered by wet methods. When work was begun in the field, only the coarse pebble (generally +1 mm) was recovered. In the 1920's a froth flotation process was developed to separate quartz from the finer phosphate fractions, but this method proved unsatisfactory for treating the intermediate fraction (-1 mm +35 mesh). Consequently various other processes were adapted, including agglomerate tabling and spiral separation of reagentized feed. Today the three processes are used-washing and screening for coarse pebble, tabling or spiraling for intermediate sizes, and flotation for -35 mesh material.

Jan 10, 1958

By H. Firmstone

DEPOSITS of cadmia, or impure oxide of zinc, are of common occurrence in the upper parts of blast furnaces using ores containing zinc, and were very common in the charcoal furnaces of Virginia working the brown hematite ores found near the Cadent black slate. These deposits were known to the old charcoal founders as "sulphur rings," and the characteristic green flame of burning zinc frequently to be seen at the tymp of furnaces working ores containing zinc, was held by them to indicate the presence of a "sulphur fall." When zinc is burning in considerable quantities at the tymp, the

Jan 1, 1879

By Eugene B. Wilson

The development of coal-mines has kept pace with the facilities at command for ventilating and lighting. In fact, it was formerly • customary to leave unworked those mines, or portions of mines, in which naked lights could not be used without danger. Attention was then turned to the ventilation; but even with improved ventilation, the naked light was often unsafe. The new era in coal-mining dates, we may say, as far back as 1815, when Sir H. Davy and Mr. George Stephenson discovered the principle of the safety-lamp. Since then many improvements have been added to their lamps, but

Jan 1, 1885

By Jan M. Mutmansky, Gordon H. Walrod, Y. J. Wang

The approach proposed in this paper is, as stated by the authors, an update of methods well discussed in the literature. The authors are to be congratulated for their excellent effort in quantifying a difficult problem with realistic cost data. Economic analysis of the components of a mine ventilation system is complicated by both the dynamic nature of the system and the uncertainty as to the time when system changes occur. We wish to address three specific areas of this paper which require further consideration: shaft designed air capacity, shaft location, and economic criteria used within the analysis

Jan 11, 1979

By H. Firmstone

Deposits of cadmia, or impure oxide of zinc, are of common occurrence in the upper parts of blast furnaces using ores containing zinc, and were very common in the charcoal furnaces of Virginia working the brown hematite ores found near the Cadent black slate. These deposits were known to the old charcoal founders as "sulphur rings," and the characteristic green flame of burning zinc frequently to be seen at the tymp of furnaces working ores containing zinc, was held by them to indicate the presence of a "sulphur fall." When zinc is burning in considerable quantities at the tymp, the

Jan 1, 1879

By Claudio Gutierrez

It has been claimed (Eadington and Rosser, 1969) that when freshly precipitated lead sulfide is in contact with oxygen-containing water, there is an "induction period" of at least a few hours during which no detectable oxidation of the lead sulfide takes place This effect would be of the utmost importance for the adsorption of xanthate on galena in flotation mills. It was tried here to reproduce the results obtained in (Eadington and Rosser, 1969), but no "induction period" was found. Besides, reasons are given to prove that the oxidation mechanism proposed by Eadington and Prosser (1969) is not realistic.

Jan 1, 1982

By Charles O. Thompson

WHEN a wire rod of iron or of steel is immersed in a hot. solution of common salt, allowed to remain long enough to bring the metal to the temperature of the brine, and withdrawn, the surface of the rod is irregularly covered with a deposit of crystals of salt. These crystals adhere to the cod with great firmness, in consequence, doubtless, of a thin film of ferric hydrate, which is formed between them and the rod as the water dries tiff. The rod can now be re¬duced, by successive passes through a dic or draw-plate, without any

Jan 1, 1881

By D. R. Skidmore, C. J. Konya

To quantify the effects of proper stemming on air-blast and flyrock reduction for a surface mining operation, a study was undertaken with funding from the Office of Surface Mining. Known weights of explosive charges were detonated in a simulated blasthole when confined with various types and size distributions of stemming. Results showed that proper selection of material type and size distribution can reduce necessary stemming length by 41 % and airblast levels by 23%. A relationship was obtained for minimum length of stemming for explosive confinement as a function of stemming size distribution and borehole diameter over a range of explosive pressures.

Jan 1, 1984

By R. Schutte, L. W. Trevoy

Commercial production of heavy minerals from plant tailing streams is undergoing study by Syncrude Canada Ltd. When tar sand from an open pit mine is processed and upgraded to synthetic crude oil, heavy minerals can be recovered from the extraction circuit and can be upgraded to provide concentrates of zircon and titanium minerals. The titanium minerals concentrate, consisting of a mixture of ilmenite, leucoxene, and rutile, can be utilized as recovered or can be upgraded to synthetic rutile. With the construction of further synthetic crude oil plants in Western Canada a large reserve of heavy minerals will become available for production.

Jan 1, 1983

By Charles M. Brinckerhoff

When I first went to Arizona in 1925, mining was primarily an underground job. Ajo, Sacramento Hill in Bisbee and Jerome were the only open pit operations in the state. Thousands of men, however, were employed in underground mining at Morenci, Miami, Inspiration, Globe, Ray, Bisbee, and Superior. The grade of ore in the larger operations was about 1-1/2% copper while a few of the smaller ones mined ore better than 2% Cu. In Utah, the Bingham pit was doing well and growing; in Montana, the vein mines of Butte still yielded ore running 6% Cu.

Jan 3, 1972

By D. A. Singer

A procedure whereby the completeness of search is calculated by using the area of influence of exploratory drill holes or samples is extended to allow for errors of recognition. The size, shape, and orientation of potential targets are mapped in a probabilistic sense on the array of drill holes or samples. The method can be used either to determine how well explored are the subregions within a previously drilled or sampled area, or to test proposed alternative search strategies. Examples of the use of the method demonstrate the complexity of sequential search when the areas of influence of drill holes or samples overlap.

Jan 1, 1976

By R. A. Wood, R. I. Jaffee, H. R. Ogden, D. N. Williams

Dispersion-containing titanium-copper alloys were prepared having mean free paths varying from 1.0 to 9.7 P. Tensile studies at room temperature and at 1000°F showed that little or no strengthening occurred when the mean free path exceeded 3 p. However, at lower values of mean free path appreczable strengthening was observed. A considerable amount of strengthening also resulted from copper in solid solution. DURING the past several years, an increasing amount of study has been devoted to dispersion hardening, an alloying process in which increased strength is obtained through the addition of a ran-

Jan 1, 1961

By W. Arthur White

Underclay squeeze is the plastic flowing of underclay below coal pillars into mined-out entries and rooms. Squeezes may be caused either by wet mine conditions where the moisture is taken up by the clay-making it more plastic-or by the presence of certain clay minerals, such as mont-morillonite, which are plastic when there is enough natural moisture. Under either condition, sufficient stress will cause the underclay to flow. Squeezes may fill an entry or room within several hours, or it may be several months before movement stops. Squeeze areas commonly cover hundreds or thousands of square yards.

Oct 1, 1956

By E. A. H. Tays

At the present time, the mine-owner has a number of patent crushers to choose from, when contemplating the erection of a mill; and a number of new ones are yearly brought to notice. We all know that the stamp-mill is the old standard; but several of the patent crushers, especially of the roller-type, are not without their merits. Having had a working experience, extending over a period of four years, with the " Bryan roller quartz-mill," working alongside of stamp-batteries, I take pleasure in giving to the members of the Institute the benefit of my experience with this mill.*

Jan 1, 1900

What has been billed as the underground drilling technology of the 1980's got a dramatic head start when Boliden engineers at Stekenjokk decided to go with all hydraulic drilling for primary ore production and mine development. This application represents a major first in meeting the needs of high productivity, better energy utilization, and an improved drilling environment. At Stekenjokk, engineers chose three Atlas Copco Boomer H132 two-boom electro-hydraulic drill rigs with the COP 1038 rock drills. An additional single-boom Boomer H131 was also selected with the COP 1038 HD for roof bolting functions.

Jan 12, 1977

By K. U. Snowden, J. N. Greenwood

EARLY studies by Gough and sopwith' have shown that the fatigue resistance of certain metals increased when the test was carried out in a partial vacuum; lead showed this effect to a marked degree. This communication describes surface deformation differences between high-purity lead fatigued in air and in a vacuum of approximately 5 X l0-3 mm Hg. Both air and vacuum tests were carried out by the same alternating flexure machine at a frequency of 500 cpm. Flat cantilever-bend specimens with tapered sides were cut from strip, annealed at 100°C, and chemically polished.

Jan 1, 1959

By T. S. Govindan

The first step in energy conservation in any industrial plant involves implementing many of the day-to-day "housekeeping" items, such as fixing leaks, turning out lights, etc. When this step has been accomplished, additional opportunities require a detailed analysis of the energy systems, evaluation of risks and costs, and assignment of priorities. Examples of conservation schemes drawn from the experience of Du Pont's Energy Management Consulting Services will be discussed. The utility of heat balances for kilns and dryers in minerals processing will be outlined. The input needed from management for the success of conservation efforts will be discussed.

Jan 1, 1981