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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 J. C. Kerkering, J. C. Franklin, T. O. Meyer, R. W. McKibbin

A continuous survey of radon gas was made in two interconnecting stopes in a southwestern U. S. uranium mine to determine how the various phases of the mining cycle affected the radon concentration. The radon was monitored continuously with five detectors. One detector monitored the intake air, one the exhaust air, and three the stope air. The radon concentrations present during slushing, blasting, and exhaust fan shutoff were compared with concentrations on a nonwork day as a base level. Inside the stope, the radon concentration increased about 40% during slushing and 425% after blasting. Intake air radon increased 1600% and the stope air increased 550% while the surface exhaust fan was off.

Jan 1, 1979

By R. D. Gibbs, C. C. Taylor

The gas-lift, or circulation of gas for the production of crude oil, now includes the gas operator in field production activities to a greater extent than ever before. It is the purpose of this paper to show the scope of his activities and to discuss the various means of handling and treating the large quantities of gas which are now of a somewhat different nature than formerly. The extent of the stripping action of circulating gas on oil must be discussed, as this can be governed somewhat by the method of treatment of the recirculated gas. Change in Gas-decline Curve under Circulation Before the advent of the gas-lift, the gas-production curve of a field showed a peak during the flush production with a rapid decline as the wells were put on the pump and then a long steady decline curve of a relatively small volume of rich gas for the life of the field. Under the gas-lift method of production, instead of having the sharp decline at the end of the flush production period, sufficient circulating gas to keep up the required total gas-oil ratio would be turned to the wells. The gas-production curve then assumes a long gradual decline, giving a large volume of gas for treatment for several years to come. The gas-decline curve will not follow that of the oil, as the lowering of the rock pressure by the steady production of oil and gas from the sand will make it necessary to continue using the large tubing and to circulate large volumes of gas in order to keep the back-pressure against the sands as low as possible. A Complicated Distributing System In tracing the flow of the gas from the time it leaves the well until it again enters through the casinghead, under high pressure, we get a very good idea of the complex distributing and regulating system that must be installed and the large treating and compression plants that are necessary (see Fig. I). Gas traps must be large enough to efficiently separate large quantities of gas and oil and should be elevated sufficiently to enable the oil, if

Jan 1, 1928

By Bruce A. Kennedy

Lufthansa flight 497 roared down the runway and climbed rapidly through the early morning mist hanging over Pudahuel airport and the city of Santiago, Chile, into the brilliant sunlight above the clouds. As the plane banked onto course for Lima, Peru, we got what was possibly our last look at the beautiful snowclad mountains that ring Santiago. To the northeast was the massive hump of Aconcagua, the highest mountain in the Southern Hemisphere, wreathed in clouds and virtually looming over Rio Blanco, the new mine put into production by Cerro de Pasco just one short year before. Almost a thousand miles to the north lay the massive open pits of Chuquicamata and Exotica, and a little closer to Santiago the El Salvador mine. Behind to the southeast, clinging to the steep slopes of the Andes, was the large and awe-inspiring El Teniente mine at Braden. These mines, once the bastions of such companies as Anaconda and Kennecott, had a new owner-the Government of Chile. On the plane were a number of people who had spent a large part of their lives in Chile operating these mines and plants, and who now were suddenly faced with the necessity of starting new lives somewhere else. To them, this was their last look at the country which not too long ago was their home, a bittersweet moment of reminiscence and a time for questioning what the future held.

Jan 1, 1971

By Dewey J. Sabin

THE Rio de Canada Honda placer property is situated at an altitude of 5500 ft. above sea level in the San Luis Mountains of the Province of San Luis, Argentina. The mine is reached by 70 km. of fair truck road, from the nearest railway station on the Ferrocarril Buenos Aires al Pacifico. The Pan-American airport at Villa Mercedes, 1.40 km. distant, serves as the most convenient point for shipment of gold. Placer mining in the Rio de Canada Honda dates from the time of the Incas and the present native population depends on the gold washed from this river and the adjacent arroyos as a means of livelihood as did the many generations before them. They dig pits to bedrock where they are not driven out by water, and mine the bedrock gravel by means of tunnels and caves. No timber is available and the ground is supported by rock cribs carefully built with the boulders encountered; or with angular blocks of slate rock taken from quarries on the surface.

Jan 1, 1936

By Alfred H. Brooks

Less than a decade ago the consumption of coal in Alaska was practically limited to the salmon canneries and the few ode-mines and settlements along the Pacific coast of the The-itory. The sparse population of the interior depended on the forests, that of the shores of Bering sea and the Arctic ocean on driftwood for fuel. All this has changed. The thousands, who have sought and mined gold on the Seward peninsula since 1898, have much impoverished the long-accumulated supply of driftwood, and at the same time the constantly increas-ng demand for fuel, on the part of the placer-camps and steamers, has resulted in heavy inroads being made on the accessible timber of the Yukon and its tributaries. While, on the one hand, the immediately available store of wood has decreased, on the other, the consumption of fuel because of the rapid expansion of the mining and fishery industries, and the attendant growth of population has much in-creased. Alaska, therefore, offers a constantly growing market or coal and other fuels. As the local coal-production has been nsignificant, the demand has been met by importations from Washington, British Columbia, and even from Pennsylvania and Australia. Fuel- Consumption. Mr. D. H. Jarvis, Collector for Alaska, has kept systematic records of the trade of the Territory since 1903. The statis-ics of the coal-importations of the past two years are shown n Table I. If data were available for a longer period of years, he increase of coal-importations would be much more striking.

Jan 1, 1906

By L. P. Teas

As sphalerite is such a common constituent of many types of ore, the present investigation was undertaken to determine what its relations are to the other minerals in the deposits, and also whether these are of any genetic significance. The data presented herewith were obtained from a mineralographic study of about 200 ore specimens from some 43 different localities, represented by suites of specimens in the Cornell University collection. These, grouped according to their genesis, were as follows: I. Contact-Metamorphic Deposits.-Silver City, N. M.; Kelly, N. M.; Silver Bell, Ariz.; Bingham, Utah; Agaguca, Michoacan, Mex.; Matehuala, Mex.; Sombreretti mine, Mex. II. Deep-Vein Zone Deposits.-Mineral, Louisa Co., Va.; Edwards, N. Y.; Chestnut Yard, Va.; Allah Cooper mine, Louisa Co., Va.; Globe, Ariz.; Moyie, B. C.; Rossland, B. C.; Broken Hill, N.S.W.; Weedon, Que.1 III. Intermediate-Vein Zone.-Park City, Utah; Leadville, Colo.; Butte, Mont.; Santa Barbara, Mex.; Red Cliff, Colo.; Burro Mountains, N. M.; Idaho Springs, Colo.; Blue River, Ore.; Rye, Colo.;1 Slocan district, B. C.; Freiberg, Ger.; Clausthal, Ger: IV. Shallow-Vein Zone.-Ouray, Colo.; Goldfield, Nev., Zacatecas, Mex.; Field, B. C.; Kapnik, Austria; Frontenac mine, Kingston, Ont. V. Meteoric Water Deposits.-Joplin, Mo.; Southwest, Wis.; Austinville, Va.; Crittenden County, Ky.; Ridgeburg, Pa.; Moresnet, Belgium. It is not supposed that the investigation of such a limited number of occurrences may warrant conclusive and universal generalizations, but the conclusions reached are believed to be reliable in so far as the specimens, that were examined are concerned.

Jan 11, 1917

By W. H. Forbes

As permissible explosives and electric detonators are now generally recognized as the only safe means of blasting in coal mines, this paper is limited to their use. Causes of Misfires There are many different causes of misfires, but the principal ones are as follows: 1. Explosives which have deteriorated through improper storage either at the storage magazine, the distributing magazine, or at the working face. This is not only true of the explosive itself, but also of its detonating agent. 2. Improper priming and charging at the working face. This commonly occurs when the explosives are handled by inexperienced persons. 3. Improper methods of tamping; the leg wires of the detonator may be abraded or broken by the tamping bar or stick, thereby causing a short or broken circuit. 4. Faulty leading wire, or electrical apparatus of insufficient strength to explode the detonator. Prevention of Misfires Storage is an important factor, especially with permissibles of a nitrate or ammonia base. Both explosives and detonators should be stored in substantially built, fire-resisting magazines and should be situated so that the minimum amount of moisture and heat is present. They should be so constructed that a constant supply of fresh air enters; the floor of the magazine should be raised to permit the circulation of air under the stored explosives. Boxes should be stored top side up and in such a manner that the old explosives are used before those of a later delivery. This eliminates chance of deterioration from lengthy storage. Detonators should be similarly handled and stored. The distributing magazine stock should be regulated so that not more than one day's supply is on hand.

Jan 1, 1930

By J. A. Bartnik, Gerald D. Rose, William H. Benson

New techniques in the magnetite and heavy media beneficiation industries demand more efficient magnetic dispersion and flocculation of the finely ground particles. Demagnetizing coils must produce several major effects, such as improving classification and screening efficiency, decreasing moisture content in filter cake and improving separation selectivity and green pellet properties. Likewise, magnetic flocculators must increase filtering rates and the settling rates of solids, improve magnetite recovery and produce cleaner water. To improve the design of equipment and to conduct tests leading to the optimization of such dispersion and flocculation, a program was initiated at Eriez Magnetics. The major conclusions reached are: 1. Laboratory and plant scale tests conducted on magnetite products show that a demagnetizing force of 450 rms oersteds at 60 cycles for 1/20- second duration will depolarize natural magnetite particles coarser than approximately 10 microns. This has been found satisfactory for most applications. 2. Effective flocculation of magnetite was obtained when a slurry with more than one percent magnetite was exposed for a period of approximately 1/15 second to a 600-gauss field. 3. The cost of demagnetizers (or flocculators) increases rapidly for larger diameter pipes. In order to reduce the cost, narrow rectangular sections are recommended for magnetic flocculators. 4. For minimum operating cost, permanent magnetic flocculators are ideal, chiefly because they do not require any maintenance and have no operating cost. 5. A newly designed electro-demagnetizing coil with high heat dissipation and a nonmetallic core provides high efficiency and long life. 6. To select the correct magnetic flocculator (or demagnetizing coil) the following information is necessary: a. Magnetic product susceptibility b. Magnetic product coercive force c. Percent of magnetic product d. Flow rate e. Viscosity f. Structure of magnetic product

Jan 8, 1968

By F. F. Sharpless

ARRIVING at Davis Junction, after leaving Portland, we expected to wait for an hour and a half, but found the superintendent of motive power of the Southern Pacific, Mr. Williams, waiting for us with a car, and were immediately taken aboard this and whisked off to Sacramento. After dinner, we were taken to the railroad shops to see their work in reclaiming scrap steel. We saw them draw off the slag from the electric furnace, and later make a casting. At about 11 o'clock, we took the train for Reno. A delegation of the Nevada Section, with Mr. Kirchen and Mr. Rives at its head, met us at the station. Immediately after breakfast, we started for the property of the Comstock Mines Co., where General Bulkeley Wells was to be our host. We had a de-lightful ride out to the mines and through the old city of Virginia, or through what was left of that old city, reaching General Wells' camp at about 10:30. This contains the newest thing in cyanidation and a remarkably fine iron and concrete mill building. After a trip underground, we were called to luncheon, where about 250 sat down. The afternoon was spent in the mill, and we were taken to Gold Hill, which is a part of Virginia City, for dinner, again as the guests of General Wells, who made a consummate toastmaster. Governor Emmet Boyle was the first speaker; he was followed by President Dwight, and then came President William Sproule of the Southern Pacific. A song, "The Engineer," was followed by Senator Key Pittman, Professor Jones of the State University, Mayor Stuart of Reno, and ex-Senator Charles Hend-erson. The president of the Western Pacific and the president of the Pacific Coast Line were there, also many notable operators of Nevada and California.

Jan 11, 1922

By J. T. Burwell

As is well known, the alloys of iron containing 18 ± per cent chromium, 8 ± per cent nickel and less than 1.2 per cent carbon exhibit the same allotropic modifications as iron. The face-centered cubic or gamma phase is stable at high temperatures and the body-centered cubic or alpha ferrite is presumably stable at room temperature. The transformation from the gamma phase to the alpha phase in alloys of the above composi-tion (18-8 or stainless steel) is sluggish; even moderately rapid cooling permits the retention of the gamma phase. Cold-work, however, causes the transformation from gamma to alpha to occur at room temperatures. It is difficult, nevertheless, to induce complete transformation regardless of the method of cold-working. Since metallographic polishing is very effective in transforming the surface austenite to ferrite, as indicated by the magnetic studies of Buehl and Wulff, 1 it was decided to investigate the phenomenon by electron diffraction methods.

Jan 1, 1939

By H. R. Wenk

This paper describes a workshop on deformation mechanisms and texture development in rocks. Empahsis is on relating macroscopic mechanical properties with microscopic structures and the methods of their quantitative analysis.

Jan 1, 1982

By A. J. Griest, J. C. Danko

IN the course of vacuum evaporation experiments, sublimation figures were observed on the surface of a pure nickel specimen. A cubic figure, typical of those observed on this specimen, is illustrated

Jan 1, 1957

By Julius Pohlman

Considering the truly wonderful natural resources of the United States, and the variety and extent of uses for hydraulic cement at the present day, it seems strange that the manufacture of the artificial product called Portland cement has not been introduced here. Possibly the reason may be we have in different States of the Union rock deposits from which a cement can be obtained that is as good, and some claim even better, because of a more uniform quality, than the English product after it has been subjected to transportation across the ocean. One of these natural cement-rock deposits is found in the northern part of the city of Buffalo, and its manufacture has been carried on successfully for the past eleven years by the Buffalo Cement co., Mr. L. J. Bennett, President. The quarries cover an area of about two hundred acres, of which only twenty-five acres have been exhausted up to date; and the supply is assured for years to come. One acre yields on an average 80,000 barrels of cement; hence 12,000,000 barrels is a low estimate of what these quarries will yield before they are exhausted. According to the Geology of New York this cement-rock deposit is called the Water-Lime group, and forms in this section the uppermost member of the Upper Silurian. Its outcrop can be traced along the base of the second limestone terrace of Western New York, but at Buffalo a very large part of the overlying Corniferous limestone has been removed by natural agencies, leaving only about eight feet (six feet of rock and two feet of clay) on the top of the cement-rock, and thus furnishing the conditions for successful quarrying at a minimum expense. This rock is really an impure limestone, a mixture, as it were, of the underlying shales of the Onondaga Salt group with the overlying

Jan 1, 1889

By Hans Lundberg, Theodor Zuschlag

Based upon an instrumental improvement, a new development has taken place in the art of electrical prospecting, and some remarkable results have already been obtained with regard to potential exploration. In order to visualize the importance of this development, it is deemed advisable to review briefly the fundamental facts about potential surveys. Potential exploration may be carried out qualitatively or quantitatively. Qualitative investigations are made by determining and plotting on a map points of equal potential, whereby any anomalies are revealed, without, however, much clue to their magnitude. Quantitative investigations determine the variations of potential or potential drop, and thus show not only the location of the anomalies, but also their magnitude. Figs. 1 to 6 illustrate the influence of simple types of ground inhomo-geneities, assuming one effective exciter potential only. Such a condition can be closely realized by connecting an electric current source to two electrodes, one of which is located at a great distance. Assuming uniform ground resistivity, the resultant potential distribution mar be represented by concentric spheres. Any change from the normal condition causes a characteristic distortion of the spheres, which becomes different for different types of resistivity variation. The series of Figs. la to 6a illustrates schematically results of qualitative investigations and series lb to 6b results of quantitative investigations. Figs. 1 and 2 picture the well-known case of local resistivity variations normally encountered in ore prospecting. Figs. 3 and 4 show the reactions caused by more or less vertical resistivity contacts and Figs. 5 and 6 refer to the problem of ground-water and bedrock investigations where the resistivity contact is horizontal or nearly SO. It is evident from Figs. 5a and 6a that qualitative measurements do not permit an identification of such general geological features as widespread horizontal strata, because the resultant contraction or expansion of the equipotential circles at the surface cannot be recognized without quantitative determinations. On the other hand, qualitative measurements are well suited for the exploration of local or lateral resistivity

Jan 1, 1932

By Eduardo Martinez Baca

Although Mexico has always been justly considered by the whole world essentially a mining country, this reputation is due principally to the richness of the deposits which have been worked. In reality, the majority of the States have been little

Jan 1, 1902

By V. J. Bishop, R. G. Beverly

Recent publicity has focused attention on the hazard of lung cancer among uranium miners. Many mining people feel the danger has been exaggerated. Whether or not this is the case, the industry must thoroughly evaluate this potential hazard and take corrective measures to minimize the threat of radiation after-effects and to maintain the level of radiation in mines within the presently-accepted limit. The measurement and control of radon gas and its solid radioactive decay products, Po-218, Pb-214, Bi- 214, and Po-214, should be the one facet of most concern to uranium miners in any radiation control program. To illustrate the radioactivity involved with small quantities of radon gas, the activity from the decay products of five milliliters of radon gas (imagine a 5-ml vial) would be adequate to raise one cubic mile of air to seven times the recommended maximum working level of 300 [ ] (micro micro curies) per liter. This would be enough radioactivity to raise to the maximum working level a 6 x 8-ft drift which extended around the world 160 times. Obviously, a little radon gas goes a long way.

Jan 8, 1961

By Robert A. Haney, Stephen J. Gigliotti, James L. Banfield

A series of investigations were made by the Mine Safety and Health Administration to evaluate the performance of various face ventilation systems as part of a program to reduce frictional ignitions of methane and to develop face ventilation systems that could be used with the line brattice more than 10 feet from the face. Tests were conducted in a full-scale laboratory model of a face area. Systems tested included unassisted blowing and exhaust line brattice, diffuser fan and spray fan systems. Systems were evaluated at air quantities ranging from 1.4 to 7.0 m3/s (3,000 to 15,000 cfm), and brattice-to-face distances from 1.5 to 9 meters (5 to 30 feet.). Tests were designed so that systems could be evaluated for the location of the high-point methane concentration in the face area, methane dilution capacity, and face ventilation index. The methane dilution capacity is the total amount of methane a system can dilute to 1.0 volume-percent. The face ventilation index is the efficiency at which the available face air volume is being used.

Jan 1, 1982

By F. W. Denton

Much has been written about the possibilities of the Vermilion and Mesabi ranges of northern Minnesota as producers of large quantities of high-grade iron-ore. The Mesabi range in particular has attracted considerable attention on account of the proximity of the ore-deposits to the surface, which has been as-

Jan 1, 1898

By J. C. Irvine

The down-the-hole drill is becoming a more common tool in today's underground mining scene. New drilling capabilities and efficiencies are being derived as experience is gained. Ancillary equipment and bits are becoming increasingly important parts of the concept. This paper describes some presently used units; underground down-the-hole drilling units.

Jan 1, 1978