Search Documents

By A. J. Weinig

The method described is a modification of Schutzenberger's whereby the solution in titrations and the standards are protected from the atmosphere by a layer of kerosene. Indigo-disulfonate is the indicator and sodium hydrosulfite the standard. The method is rapid and delicate. It has been tried on a variety of mill solutions and mill men have found the method of value. THE important part that dissolved oxygen plays in the cyanide treat-ment of gold and silver ores is commonly recognized by most metallurgists and mill men.. But heretofore there has been no simple method on which the mill man could rely for determining the amount of oxygen in the various mill solutions. A few methods are adaptable to the, laboratory, such as the gasometric1 determination by actually measuring the oxygen. Winkler's2 iodometric method, and Schutzenberger's3 method, which depends on the reducing action of sodium hyposulfite on a blue solution of indigo carmine; but these are not readily adaptable to the needs of the mill man and cannot be applied to cyanide solutions without modification. The gasometric method is the most accurate but it takes too long to complete a determination. White's' method (a colorimetric method that depends on the degree of coloration imparted to a solution of pyrogallic acid in the presence of caustic soda) although much more rapid than any of the methods named, often gives misleading results on account of grading of colors of different solutions, which nearly always contain various kinds of salts. The method herein described was devised for the use of the mill man, the aim being to develop a simple, practical, accurate method. It is a modification of the Schutzenberger method and depends on the reducing

Jan 8, 1924

By J. C. Osler

The design of a tailings dam is a geotechnical engineering project of considerable scope. For the design, it is necessary to establish the engineering properties of the soil or rock strata which will support the dam and the tailings or other fill which will be used to construct the dam. The various field and laboratory investigations which are necessary to obtain the required design parameters are discussed in the paper and the use of these parameters to compute stability, settlement, and seepage are considered. The designer of a tailings dam can never assume an absolute knowledge of the properties of the foundation strata. Further, initial design assumptions are often approximate, particularly with regard to the distribution of pore pressures through and beneath the dam. Thus, the installation of performance monitoring instruments is recommended, since data obtained from such instrumentation can be used to check the stability of the structure both during construction and after its completion.

Jan 1, 1972

By E. P. Pfleider, W. D. Lacabanne

Rotary percussive drilling, vibro-drilling, vibro-rotation drilling, rotary pulsating drilling-all names that mean the same thing-are gradually appearing in mining literature. What is rotary percussive drilling? It is a combined system superimposing a rapid percussive impact on a continuous rotary action in an attempt to utilize the most desirable features of both methods. At present single and multiple carriage-mounted rotary percussion units are being used in the European coal mining regions. One well engineered unit is the Hausherr "Albo" rotary percussive drill, utilizing two alternately operating percussion pistons, and another is the multiple-unit, jumbo-mounted Salzgitter machine. Niisse & Grafer also manufacture rotary percussion drills.

Sep 1, 1955

By A. S. Rhea

SALT-WATER disposal in the East Texas field by means of injection into the Woodbine sand is a relatively new procedure. The purpose of this paper is to present what has been accomplished to date in this field, with-out detailed discussion of other means of disposal, such as surface impound-ing for evaporation or release into surface streams. Subsurface disposal of salt water is still in an experimental stage in the East Texas field, and, though water can be injected into the Woodbine sand, the economic problem is not as yet solved. As past experience has been that fields producing from the Woodbine formation produce large quantities of salt water, it was assumed early in development of East Texas that it would be necessary to dispose of a tremendous quantity of salt water in the later periods of production. There has been a gradual increase in the amount of salt water pro-duced in the field, until at present it is about 200,000 bbl. per day from approximately 4400 wells. It is only natural to expect an increase in the number of wells producing water, as well as the amount of water produced in the future, and it has been estimated that if present practices con-tinue the production of salt water may ultimately be as much as 700,-000 bbl. per day. The Woodbine sand is found in the East Texas field at an average depth of 3650 ft. The oil-bearing portion of the sand lies between the depths of 3050 ft. below sea level, on the east edge of the field, and 3320 ft. below sea level on the west, which depth was the estimated original average oil-water contact. The Woodbine sand under the field has the form of a broad tilted wedge pinching out on the eastern side of the field and dipping gently into the East Texas Basin toward the west. The Woodbine sand in the East Texas field has an average porosity of approximately 25 per cent and is highly permeable, the average being about 1300 millidarcys.

Jan 1, 1940

By P. E. Schauer

During the initial nine-year deple-tion of the McKamie-Patton pool gas-condensate reservoir, the pressure behavior and fluid analyses indicated pressure maintenance by gas injection would be attractive relative to continued pressure depletion. As a result, a gas cycling program was inaugurated in Aug., 1949, which has since maintained reservoir pressure. In order to evaluate the benefits of this program, the recoveries for natural depletion and for cycling followed by blowdown were determined by calculating the fractional balance of the molar quantities of vapor and liquid remaining in the reservoir and produced at the surface for various stages of depletion. The results of the investigation show theoretical ultimate recovery due to the cycling program will be 42 per cent greater than would be realized under pressure depletion type operation. INTRODUCTION The benefits of gas injection pressure maintenance programs in condensate reservoirs have been recognized and qualitatively described in several papers1-8 during the past 15 years. Some of these papers also describe methods for calculating the increased recovery realized from cycling; however, as a rule, hypothetical reservoirs were used as examples".'.. This paper presents an evaluation of the pressure maintenance program for the McKamie-Patton condensate reservoir and includes a description of the fractional balance method employed to determine the benefits. Reservoir Development and Characteristics The McKamie-Patton pool, Lafayette County, Ark., was opened in June, 1940, with production obtained from the oolitic Smackover lime at a depth of approximately 9,300 ft. The structure is an anticline 8 miles long by 1 to 2 miles wide, and is one of many productive Smackover structures in Southern Arkansas. Of predominant importance is the condensate-bearing gas cap portion of the reservoir, which covers approximately 4,000 acres, attains a maximum thickness of some 200 ft, and has an average thickness of 90 ft. Development of the cap was accomplished with 21 wells drilled on 160 acre spacing. An isopach map of the cap is shown in Fig. 1. In addition, an oil rim is present along most of the periphery of the pool. Production practice includes field separation of black oil, and a high pressure gathering system which carries total well stream from gas cap wells to a plant where condensate is separated and the gas is processed for recovery of natural gasoline, butane, and propane. Since the gas contains appreciable hydrogen sulfide, it is removed by amine contact, after which free sulfur is produced by the Claus process. Core analyses from 1,767 gas cap formation samples averaged 14.2 per cent porosity and 379 md dry air permeability. Connate water was restored on seven samples of gas cap rock by air-brine capillary techniques, from which the interpreted water saturation averaged 28.17 per cent. During the early life of the field, it was believed the recovery mechanism, based on several of the other regional Smackover reservoirs, might be a natural water drive. However, subsequent production and pressure history revealed that the gas cap would not be produced by water drive, but would behave as a closed reservoir. In this respect, during the nine-year period of natural depletion from initial production to Aug., 1949, the cap production of 84.3 billion

Jan 1, 1958

Jan 1, 1914

Jan 1, 1937

By Bruce Vandre

Jan 1, 1985

By Don Blackmar

THE production of non-ferrous secondary metals has become a large and important industry in the United States, and deals with practically every type of manufacturing concern. Its business is unique in that it generally buys from its customers as well as sells to them, whether they are individuals, cities, corporations, or the United States government. Its operations are of vital importance to the success and prosperity of many of the nation's most important manufacturers; yet there are few industries about which less is generally known by those outside it, whether concerning the magnitude of its operations or the details of its actual technique. The industry itself is to blame for this meager publicity, because its technical men have made few attempts to openly exchange ideas, in spite of the excellent examples set by the iron and steel or the copper and brass industries. Whether this is due to the ancient shroud of secrecy generally supposed to cover smelting operations, or because its technical men actually felt that the industry was too puny to be interesting, is hard to say. This paper will consider its subject in a general way, attempting to show something of the size and importance of the industry, as well as its fitness to do its work well. Attention will be called to the sound economic reasons for the handling of non-ferrous wastes by specialists, and to the often unseen losses of metals and labor which occur when manufacturers reclaim their own metallic wastes.

Jan 1, 1928

By J. Walter Snavely

PRESENT-DAY processing in many industries, calcining, sintering, briquetting, beneficiation and nodulizing, increasingly calls for the handling of large volumes of hot bulk materials. Various types of conveyors have been employed. This discussion will cover the factors governing their selection. For temperature ranges up to 400°F, or approximately 200°C, a wide range of conveyors is available. Special constructions of rubber conveyor belts. steel conveyor belts, vibrating and shaker conveyors, apron conveyors, and drag chain conveyors, all are used successfully. As temperatures go well above 400°F, however, choice of conveyors is narrowly limited. This paper will consider the problem of handling bulk materials only where the temperatures exceed 400°F.

Jan 5, 1953

By H. W. Turner

In addition to the deposits mentioned by Mr. Lindgren? the following may be noted: 1. In the " Dardanelles quadrangle," of the map of the U. S. Geological Survey, 3 miles NW. of Tower Peak, there is a considerable mass of quartzite, marble, and dark, fine-grained. gneiss. At the edge of the coarsely crystalline white marble, having a width of about 400 ft., is a white schistose rock, which,

Jan 1, 1904

By R. J. Lipp, I. Iwasaki, R. H. Heerema

The presence of calcium ion in iron ore pulps that are upgraded by selective desliming can result in indiscriminate flocculation of both iron oxide and siliceous gangue slimes. In order to overcome this adverse effect, deflocculation by three complexing agents, namely ethylenediaminetetzaacetate (EDTA), sodium tripolyphosphate (STPP), and sodium hexametaphosphate (SHMP), was investigated. The precipitates and complexes of these agents with calcium ion were characterized by potentiometric and conductometric titrations, and the surface properties of quartz and goethite were studied in the presence of calcium ion and of the complexing agents by means of streaming potential measurements and flotation tests. The results were then correlated with selective flocculation tests on an artificial mixture of quartz and goethite. EDTA markedly improved the selectivity of flocculation when added in near stoichiometric amounts, whereas STPP was less effective and SHMP was totally ineffective due to strong, indiscriminate dispersion. Remanent calcium polyphosphates on the goethite surface interfered with the adsorption of starch flocculant.

Jan 1, 1983

By S. G. Malghan, J. P. Van Dillen

Some uranium minerals are paramagnetic and hence are amenable to concentration by high gradient magnetic separation (HGMS). This paper describes effects of the HGMS parameters-pulp velocity, field strength, matrix loading, and magnetic field gradient-on the product recovery and grade. Unsatisfactory separation of uranium minerals by HGMS is related to ore-specific properties, such as lack of liberation, fine dissemination of uranium minerals, uniform distribution of magnetic minerals throughout the ore matrix, and interference of fine-sized slimes. Experimental techniques to identify and resolve some of these problems are outlined.

Jan 1, 1984

On Wednesday evening, Jan. 27, 1915, were held in the auditorium of the Engineering Societies Building the inaugural exercises of The Engineering Foundation, established by the United Engineering Society. The initial gift to the Foundation of $200,000, made by Ambrose Swasey, Past President of the American Society of Mechanical Engineers, was formally accepted at this time. So far as known this is the first instance of a foundation devoted to engineering purposes. This meeting con-stituted also an appropriate tribute to the generous gift made to the Foundation and gave opportunity for expression of the satisfaction and approval which are felt by engineers everywhere at the establishment of a means of promoting the good of mankind through the work of the engineer along the broadest lines. Gano Dunn, President of the United Engineering Society and Past President of the American Institute of Electrical Engineers, acted as presiding officer, and on the platform were seated representatives of the three societies constituting the United Engineering Society, and of the American Society of Civil Engineers. Members of the four societies and many other friends interested in the profession composed the audience.

Jan 3, 1915

By David J. Dunn, Richard G. Martin

Of many physical parameters critical to design of grinding processes, impact of grinding media is among the most difficult to measure or predict. Yet impact of falling grinding balls, pebbles, or rods accomplishes the fine grinding essential to metallurgical recovery of most important minerals. Unfortunately, the same impacts that break ore fragments deform or crack grinding mill liners. A project was undertaken at Climax Molybdenum Company to measure impact forces in operating ball mills so that they might be used to calculate stresses in liner materials and be correlated with service performance of mill liner alloys. Towards that end, a method of measuring impact forces on ball mill liners using an instrumented grinding ball has been developed. Preliminary tests show that impact forces and contact stresses imposed on bare mill liners are quite high but are greatly reduced by cushioning when coarse ore particles are crushed between balls and liners.

Jan 4, 1978

By John Chipman

IT has been long known that the gas evolved during the boil in the open-hearth furnace is mainly carbon monoxide associated with smaller quantities of other gases. A number of attempts have been made to determine the precise effects of carbon and oxygen content of the bath, and of other factors, such as temperature, upon the evolution of carbon monoxide. In his investigation of the carbon-iron oxide product in liquid steel, Herty1 showed that the value of this product at equilibrium could be approximated by plotting the value of the product observed in open-hearth reactions against rate of carbon elimination, and extrapolating to zero rate. The results of this study showed a slight but definite effect of temperature upon the carbon-iron oxide reaction. Experimental studies of the evolution of gases from rimming-steel ingots have not yet attained the degree of precision necessary for an exact understanding of the effects of pouring temperature, carbon content, and iron oxide in the metal upon the composition of these gases. Klinger2 showed that the gas consists mainly of carbon monoxide, and that con-siderable variation in its composition occurs during the solidification of the ingot. In order that these variations may be understood in their proper relationship to the progress of solidification of the ingot and the segrega-tion that accompanies solidification, it is essential to have a knowledge of the condition of equilibrium in the several chemical reactions by which the gases are being formed. It is also necessary to understand the effects of temperature upon the equilibria, and further, to know the manner in which the temperature of the liquid metal within the ingot changes as the skin of the ingot is being built up. The reactions in which we will be chiefly interested are those involving in the one case the oxides of carbon, and in the other case steam and hydrogen, with iron oxide and carbon in the liquid metal. The reactions as they occur in unalloyed liquid iron, and their respective equilibrium constants are written as follows:

Jan 1, 1937

By W. A. Nordland

BISMUTH can be readily grown into single-crystal form using the so-called "quick freeze" growth method.' Some advantages of this method are that very large crystals can be grown in a relatively short time, and with comparatively simple apparatus. We have found the general quality of crystals grown by this method to be not as good as that of "pulled" crystals.' This communication describes a "quick-freeze"

Jan 1, 1968

By J. J. Gilman

The dependence of ortho kink-band formation on crystal orientation, on temperature, and on the conditions at the ends of a specimen is described. Load-compression curves for crystals that kink are presented. The reversibility of ortho kinking is demonstrated, and motion of kink planes through crystals is shown. Finally, a phenomenological explanation of ortho kink-band formation is given. ORTHO compressive kink bands (Fig. la) were discovered for the case of metals by Orowan,1 and they have been discussed by Jillson2 and in some detail by Hess and Barrett." However, their history in nonmetallic crystals is considerably older. It is not known when they were first observed in mineral crystals, but descriptions of them may be found as early as 1885.* They were sometimes mistaken for twins.6 Mügge seems to have been first to realize their true nature and importance. He reviewed the knowledge of them for a wide variety of crystals: anhydrite, antimonite, kyanite, vivianite, gypsum, mica, graphite, molybdenite, barium bromide, cal-cite, sodium nitrate, and barite. Also, the "twins" observed by Bridgman7 in sapphire crystals resemble kink bands more than twins. The terms ortho and para kink bands have been coined in order to distinguish between two types of kink bands which seem to represent the same geometrical configurations, but which have different origins and sizes. Ortho kink bands are the usual type that form at low loads when zinc crystals are compressed parallel to the basal plane. Para kink bands form at much higher loads in highly deformed crystals. These terms refer to compression phenomena and are not to be confused with analogous tension phenomena such as tensile kink bands and deformation bands. Mügge described the geometry of ortho kink bands quite completely for kyanite crystals, Fig. lc. The geometry observed for cadmium by Orowan1 and for zinc by Hess and Barrett3 is very similar to that described by Mügge. (See Hess and Barrett for a complete discussion.) Mügge associated kinking with bending combined with basal slip. He pointed out that the kink angles

Jan 1, 1955

By G. Adel, J. Richard Lucas, C. Haycocks

This paper describes over sixteen computer programs developed at Virginia Polytechnic Institute and State University during the past twenty years to assist in the design of coal operations. Overall development concepts in the construction of the programs are outlined, commencing with those used in the exploration phase of mining and extending through economic analysis and into the design of specific engineering systems such as belt, rail and power networks, scheduling, rock mechanics problems and simulation of face systems. Summarized information is given for the use of the major programs including user restrictions, input data, typical output and industrial applications and case studies. Analysis has been made of the programs' applications by industry throughout the world. Such analysis is facilitating development of new programs as well as a refinement of existing ones. To date programs have been constructed in four categories: exploration, ground control, economic and simulation. Face production simulations are stochastic in nature and require the use of time study data obtained at sites underground. Future programming efforts currently under development are aimed at interactive programs for use with minicomputers and, where advantageous, with graphical displays.

Jan 1, 1983

By Joseph E. Worthington

Many thousands of years ago when our earliest ancestor first swung out of a tree, picked up a rock, and threw it at what he hoped might be his lunch, the minerals industry, in a manner of speaking, was born. It was then a very long step indeed to the primitive metal industry of our early civilizations, for we know that precious metals were accumulated and some metal objects were produced several thousand years ago. Prospecting, or "exploration" to use the modern euphemism, consisted of little more than outcrop examination and the use of a gold pan, and it probably did not change much from our earliest civilizations until relatively recent times. In a general sense, all the early explorers of North America were also prospectors, for mineral wealth was certainly one of the goals of the first pioneers and settlers. The earliest pioneers didn't do too badly either, for they discovered copper and iron in various places in the Appalachians and Michigan, gold in the Southeast Piedmont and many mineralized areas in the Southwest. In most places these were outcropping ores or gossans, and the prospecting was incidental to the arduous task of ekeing out a living in a new land. It was the explosive discovery of rich placer gold deposits at Sutter's Mill in California that caught the public fancy and precipitated the establishment of prospecting as a full-time occupation. After the end of the Civil War in 1865, full-time prospecting became an important occupation and continued as such for almost three generations. Prospectors equipped with picks, shovels, gold pans and four-footed transportation swarmed all over what are now our Western States, discovering thousands upon thousands of mineral showings-and certainly most of today's large mining districts. Our vigorous western mining industry is a tribute to the courage and persistence of these men. The techniques of these picturesque prospectors, however, were essentially the same as those of their predecessors-examination of every outcrop and assiduous use of the gold pan. The great increase in discovery at this time was therefore due to increased activity rather than to different techniques. An important result of this in- creased prospecting was the growth of interest in geology. It was during this period that the U.S. Geological Survey began to grow. Many of the major mining districts were mapped, and geological studies and projections began to have an impact on further ore discovery. Ore search and development gradually became more geologically oriented and the geologist became a fixture in most mining camps by the 20th century. The development of mass-mining techniques in the early part of the century also changed exploration concepts.

Jan 1, 1971