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By J. P. Capp

This experiment, one of a series on underground gasification of coal, was an investigation by the Federal Bureau of Mines of hydraulic fracturing as a means of increasing the air acceptance of a coalbed to permit introducing combustion air and removing product gases. Specific objectives of the investigation included: (1) Fracturing a coalbed; (2) determining the distance the coal was physically affected; (3) ascertaining the effect of the fracture on air acceptance of the coalbed; and (4) gasifying the coal. The coal was fractured with a fluid consisting of 15,000 lb. of sand mixed with 10,000 gal. of fuel oil and 5,000 gal. of kerosine, injected at pressures up to 900 p.s.i.g. and rates up to 425 g.p.m. The oil served as the fracturing medium, and the sand as a propping agent to hold the fracture open. From the fracture point, (the place in the bed where the fluid was injected), the fracture extended 200 ft. or more along the face cleats, somewhat less along the butt. cleats, and was confined to the coalbed. At the fracture point, the bed accepted about 500 std. c.f.m. of air, which was an etghtyfold increase. Fracture effects were extensive, as airflow was noted from old mine workings and outcrops 600 to 800 ft. from the fracture point. It is probable the actual fracture was much less than 600 ft. and that normal coalbed permeability beyond the fracture limits was responsible for this flow. This indicated that effects of the fracture extended beyond the area of coal physically affected. Although no attempt was made to gasify coal more than 200 ft. away, these effects plus the natural permeability of the bed likely would permit combustion beyond the outer limit of the fracture. As these experiments continued for more than 2 years, and greater air acceptance due to the fracture was observed at the beginning of each test, it is apparent that the effects of the fracturing persist for a considerable time.

Jan 1, 1960

By A. Asadi

Subsidence phenomenon as an unwanted consequence of underground mining can cause problems for environment and surface structures in mine area. Surface subsidence prediction for inclined and steep seams has been given less attention than horizontal seams due to the difficulties involved in the extraction of such coal-seams. This paper introduces a new profile function method for prediction of surface subsidence due to inclined coal-seam mining. The results of calculation with the new function indicate that the predicted value has good agreement with the measured data. Keywords: subsidence; coalmining; caving mining methods; longwall mining; profile function.

Jan 1, 2005

By D. T. Pritchard

"Introduction""No accounting system is very good, and all of them are infinitely variable*.”The purpose of this chapter is to discuss those facets of a typical accounting system which are most commonly encountered by operating managers in mineral processing plants. However, before concentrating in any detail on these it is important to understand the broad purposes and basic techniques of any accounting system in any major business.The three broad purposes of an Accounting System are:- Administering, controlling, and recording the flow of cash in and out of the business. Cash is, of course, converted into other assets (or stores of value) such as inventory, plant and equipment, etc. These assets also have to be administered, controlled and recorded.- Internal reporting to Management for information, for control, and for use in making business plans and decisions. - External reporting to stockholders, government, lenders and other outside parties.In this chapter we shall organize our discussion of accounting practice in mineral processing plants around these three purposes of accounting and focus in some detail on specific practices and techniques with which operating personnel will be routinely involved. This chapter is divided into the following: Accounting Basics; Administration, Control and Recording of Cash Flows; Internal Reporting; Planning and Budgeting; Cost Control; and External Reporting."

Jan 1, 1989

By Kristian E. Waters, Hao Ma, Haibei Wang

Over the past few decades, ELM based separation processes have become an attractive and efficient way to remove toxic metal ions from the various aqueous waste effluent streams. This paper provides a comprehensive review of the generation, characterization, and applications of emulsion liquid membrane (ELM) from the more than 280 papers and books published so far. First, the ELM formation and the transport mechanism are introduced. Then the ELM stability and emulsion splitting methods are discussed in detail, followed by the latest research and findings of the extraction of copper and nickel using the ELM technique during the past few decades, including a thorough discussion of ELM operating parameters that impact ELM stability and extraction. In addition, the kinetics study and industrial application of this technique for the removal of coppers/nickel solutes are also presented and discussed.

Jan 6, 2023

By R. C. A. Thurston

"The lack of notch ductility in structural steel in general, and in ship plate in particular, has been the object of widespread attention in the metallurgical world since the spectacular collapse of the ill-fated S.S. Schenectady in 1943. Numerous investigations have been carried out, many new tests have been developed, and a vast amount of useful data has been published, with the result that our knowledge is now far more advanced than it was at the time of this disaster. Interest has focused largely on the medium strength steels, and the various factors which cause a normally ductile steel to behave in a brittle manner in the presence of a notch and at relatively .low temperatures have been thoroughly studied.The literature available on high-tensile steels, however, is less extensive and the present paper is intended to supplement this information. Notch toughness tests have been carried out, at the request of the R.C.N., on a high-tensile manganese steel in the form of commercial ship plate. One of the newer tests, the tear test, and the Charpy V-notch impact test, were used to examine the characteristics of plate for the construction of an ice-breaker. About 250 plates, mainly in the thickness range from 11,4 in. to 1 % in., were tested. An an-alysis of the results obtained is presented, certain aspects of the tear test are discussed, and the correlation between the two types of test is studied. On the basis of information available from casualty ships, the plates, with few exceptions, were considered to be satisfactory."

Jan 1, 1959

By James W. Cameron

DESPITE the fact that, after oxygen and silicon, aluminum is the most abundant and widely distributed element in the earth's crust, it is, commercially, a modern metal. Attempts were made by Sir Humphrey Davy and other chemists to decompose alumina, the oxide, into its elements, but with unsatisfactory results, and it was not until 1827 that Wohler succeeded for the first time in isolating the metal in pure form. Some thirty years later, commercial production of aluminum was started in a plant near Alais, France, using a process developed by Deville which was a modification of that of Wohler. It was not, however, until around 1886 that possibilities of low-cost production were realized. Hall and Heroult discovered, independently, the now famous process for extraction of aluminum by the electrolysis of alumina (Al,O,) dissolved in fused cryolite. This discovery, with its subsequent effect in reducing the price of the metal, was perhaps the greatest single factor contributing to the remarkable growth of the aluminum industry. But only in the years following the Great War did aluminum begin to attain equal importance in many fields with other non-ferrous metals. Numerous factors, political and economic, in the past decade have had a profound effect on the industrial history of the metal. At present, systematic substitution of aluminum for other base-metals is proceeding at a rapid rate in such countries as Germany and Italy with a view towards 'economic self-sufficiency'. Quite naturally, ?the economic depression started extensive research and experiment in various industries in an attempt to improve efficiencies and lower costs. Partial answers have been found in the extended use of aluminum and its alloys. Even against the background of tremendous technological advance that has marked the past fifty years, the rise of the aluminum industry must necessarily stand out conspicuously.

Jan 1, 1939

By Lily Ruíz

El presente texto evalúa el relave minero de SIMSA con el objetivo de obtener un producto ecológico que pueda ser utilizado como mejorador cationico de suelos y restaure el equilibrio de los suelos ácidos de la selva peruana. Para ello, se desarrolló un trabajo a nivel de laboratorio, obteniéndose resultados satisfactorios. Posteriormente se pasó al nivel piloto donde a través de la experimentación se utilizó el relave en diferentes concentraciones para la producción agrícola y forestal, reafirmando los resultados en las mejoras de la productividad en suelos ácidos.

Sep 9, 2007

By Roger C. Malan

The Monument Valley and White Canyon districts are in northeastern Arizona and southeastern Utah. Exploration and mining for uranium has been conducted in these districts since the late 1940's. In July 1965, ore reserves plus ore production at 174 properties were approximately 3.3 million tons of ore containing about 19 million pounds U3O8, of which about 10 per cent remained in reserves. The two largest mines, Monument No. 2 and Happy Jack, together account for about 45 per cent of the sum of production and reserves. Approximately half the deposits in these districts contain less than 1000 tons of ore. Nearly 5000 feet of Permian, Triassic, and Jurassic sedimentary rocks, mainly continental in origin, are exposed in these districts. All the important uranium deposits are in the Shinarump, the basal member of the Chinle Formation of Triassic age. The Shinarump lies on a widespread unconformity. It is composed of fluvial sediments, generally less than 100 feet thick, that were deposited by streams flowing from a source to the south. Most of the deposits are in an arcuate belt, convex to the west. This belt, 3 to 12 miles wide, extends from Monument Valley northward nearly 130 miles. It is along the western flank of the ancient Monument Valley-Monticello upland, an area that was slightly uplifted at the beginning and again at the end of deposition of the Shinarump. Erosion and subsequent reworking of the Shinarump sediments in the vicinity of this upland are postulated to have made possible the transportation, in solution, of the uranium contained in these sediments. The soluble uranium probably was carried by migrating ground water into sites favorable for precipitation in Shinarump beds bordering the upland. Thus, the original very small amounts of dispersed uranium in the early Shinarump sediments were accreted in the favorable belt where the accumulations of carbonaceous plant remains and their decay products provided a persistent reducing environment.

Jan 1, 1968

By Jörn M. Seitz

Dynamic load testing is employed with ever increasing frequency to estimate the strength and elastic settlement behavior of piles of all types. For dynamic loading ram masses up to 20 Mg have been used and pile resistance forces up to 30 MN have been activated. Strains and accelerations induced by the impact are measured near the pile top and a load-set curve is computed by the so-called CAPWAP method. This paper briefly describes both the necessary equipment and other details of the dynamic tests and the available analytical tools for data interpretation. Furthermore the need for further research and the current status of standardization will be discussed. This paper also presents the results from several static and dynamic correlation tests on cast-in-situ piles of up to 2 m diameter and 64 m length. The results demonstrate the economical and technical feasibility of this test method.

Jan 1, 1987

Keywords: Pyrometallurgy, zinc, electrowinning Zincor has been producing zinc since 1969 via the roast-leach-electrowinning process. It is the only primary zinc producer in South Africa, and currently supplies the entire country with zinc. The plant was built by Goldfields of South Africa, on the site of an old gold and uranium mine. Since then, the ownership of the plant has changed a couple of times, and the plant and process have also been improved. Production output has increased from around 80 000 tons per year to more than 110 000 tons per year. This was done mainly through increasing the capacity of the roasters and acid plant. Zincor produces four main grades of zinc: SHG, Zn1, Zn2, and Zn4, in three shapes: a 25 kg ingot and 1 and 2 ton jumbos. In 2005, a pre-alloy furnace was built that enabled the production of jumbos pre-alloyed with aluminium. This has allowed Zincor's customers to improve the efficiency of their continuous galvanizing lines and to lower their production costs.

Jan 1, 2006

By E. J. Kloos

One phase of the work of the Bureau of Mines in health and safety is promoting the use of safe, satisfactory, and reliable respiratory-protective devices. To insure that such devices will be available, the Bureau has established schedules of minimum-performance requirements for the approval of self-contained breathing apparatus (1),4/ gas masks (2), supplied-air respirators (hose masks, air-line respirators, and abrasive-blasting helmets, hoods, or masks) (3), dispersoid (dust, fume, and mist) respirators (4), and nonemergency gas respirators (chemical-cartridge respirators) (5). Approval tests of self-contained breathing apparatus are conducted by Health and Safety District B; approval tests of other types of respiratory-protective devices are conducted by the Branch of Health Research. Manufacturers of respiratory-protective devices may submit their equipment to the Bureau of Mines for approval under the requirements of these schedules. If the device, when tested by the Bureau, meets the schedule requirements, a certificate of approval will be granted, which not only states that the equipment has passed the schedule requirements but also gives information about the limitations of the device. If it is found at any time that approved devices do not meet the requirements of the pertinent schedule, the Bureau may rescind approval.

Jan 1, 1959

By Gordon Kidd

Inflation and burgeoning costs are two among many factors which have generated a new surge of interest in "fringe benefits" (sometimes referred to as "supplementary remuneration" or "supplementary compensation"). Other specialized forms of compensation ("perks", in the vernacular) such as company cars, windowed offices, etc., which also are the subjects of current study, are outside the scope of this paper. For businesses, interest in fringe benefits is based on concern for employees? welfare, compliance with government requirements, and an increasingly burdensome impact on bottom lines. In 1980, according to Fred D. Lindsey in the October 1980 issue of Nation's Business, employee benefits will cost American employers an estimated $420 billion. To paraphrase Winston Churchill, "some fringes!" Indeed, few if any administrators consider employee benefits as fringes. Employee benefits impact other major areas of a company's operations as well. As listed by Beadle (1980), these areas include employee relations, collective bargaining, short-term costs, long-range funding, manpower planning, compliance with legislation, taxation for the company and for the employee, corporate image in the community, competitiveness for staff, communications, administration, claims cost containment, etc., etc.

Jan 1, 1980

By Manuel Villanueva Bullón

El presente trabajo describe la factibilidad del programa por computadora en los proyectos de minado no masivo a cielo abierto. Dicho programa permite calcular la cubicación del mineral como del material estéril para los tres ángulos de talud diferentes, as leyes de veta sin diluir y las relaciones desmonte-mineral para cada sección y zona explotada. En este sentido, la utilización de la computadora ahorra tiempo en los cálculos, aprovechándolo en beneficio del planeamiento de operaciones mineras.

Nov 20, 1978

By William H. Schiffbauer

The U.S. Bureau of Mines has been investigating methods and technology that may improve safety and production when applied to existing mining machines. Toward those goals, the Bureau has developed navigation systems that provide machine positional information while in the production area. This research has been limited in the past because the Bureau had only one type of mining machine to do experiments. Addressing this problem, the Bureau, along with Carnegie Mellon University, has developed a generic vehicle emulator, in the form of a wheeled vehicle with an onboard computer, known as the Locomotion Emulator, that provides a software-selectable vehicle emulation package. Preliminary testing by the Bureau has shown that the emulator can accurately imitate the maneuvers of the software selected vehicle type. Now the Bureau can test their navigation systems on different vehicle types without having to procure each of the vehicles. This report completely describes the emulator as well as all the modes in which it can be operated.

Jan 1, 1991

By E. J. Matson

This report covers the investigation of the MacArthur copper deposit and several adjacent claims in the Mason mining district; Lyon County, Nev. (fig. 1). As a part of the Bureau of Mines program of investigation and development of domestic mineral deposits, a project was begun first on the MacArthur claims. Work was done later on some adjacent claims in the immediate area, as shown by figure 2. Field work was begun by the Bureau of Mines on January 16, 1950, and completed on October 25, 1950. Eight diamond-drill holes were completed, for an aggregate of 3,414 linear feet, Analyses were made of' each drilling interval. The report includes a brief history of the district and a description of the deposits and of the work done by the Bureau of Mines.

Jan 1, 1952

By Niklas Willemsen

Introduction to SVCs ? SVC = Static var Compensator ? Dynamic step-less control of reactive power without switching of passive components: ? Voltage control/stabilization ? Harmonics- and flicker mitigation ? Dip mitigation ? Main components: ? TCR (Thyristor Controlled Reactor) ? Tuned harmonic filters ? Control- and cooling systems ? Typical applications: ? Mine hoists ? Large mining complexes ? EAF, SAF, rolling mills, wind/solar farms etc..

Aug 1, 2013

By Alfred Bodenlos

El presente texto señala los depósitos de zinc y plomos encontrados en los cateos del flanco noroeste del cerro Huancapetí, perteneciente a la Cordillera Negra. En el flanco noroccidental del cerro Huancapetí, hay varias vetas que han sido exploradas por pequeños cateos, cuyas altitudes van desde 4480 hasta 4670 metros. Para llegar a esas vetas solo hay caminos malos que cruzan la cumbre de la cordillera al sur del área de la mina Huancapetí. De otro lado, en 1947 la única mina en actividad era la de Wilson, alcanzando 10 toneladas de concentrados al mes escogidos a mano, así como la mina San Idelfonso, la Improvisada, Mariscal y los cateos Señor de la Soledad y Fernandiita.

Nov 1, 1957

By Kazuya Kitatani, Gen Sasaki, Naoto Ohta, Hideharu Fukunaga, Makoto Yoshida, Jin Pan, Kenya Nagahisa, Toshihiro Ishikawa

"A sintered SiC (Tyranno-SA) fiber-reinforced MAS glass matrix composite was fabricated by using a slurry infiltration method and hot-pressing. The microstructure and mechanical properties were investigated: To prepare the preform, the MAS glass slurry including a dispersing agent was infiltrated into a bundle of the fibers. The preform was then hot-pressed under the conditions of 1473 K, 30 MPa, 3.6 ksec. A unidirectionally-reinforced oxide matrix composite with 50% Vf. of the fiber and a density of 2.84 g/cm3 was obtained. As the mechanical properties at room temperature, the three-point flexural strength- and quasi-static adsorbed energy were 500 MPa arid 6,000 J/m2, respectively. Without graphite or an h-BN pre-coating on the surface of the fiber, pull-out and bridging of the fibers from the matrix was found, and this leads to a high value of the adsorbed energy. By TEM observation, nano-scale crystalline products were found between the fibers and the glass matrix. The push-out test reveals that this layer causes the appropriate debonding of the interface during the fracture process of the composite.Introduction It is known that the CFCCs (continuous-fiber-reinforced ceramic matrix composites) are characterized by their non-linear fracture behavior, which is' hardly found in monolithic ceramic materials. It is inevitable for the CFCCs to exhibit a large fracture toughness so 'that debonding of the fiber/matrix interface; pull-out and bridging of the fibers then' occurs during the fracture process. This series of fracture behavior is known as the so-called ""the mechanism of toughening of the CFCCs"". Thus, different from the MMCs in which strong interfacial bonding is necessary, the interfacial strength of the CFCCs has to be controlled. As techniques for controlling the interfacial strength, it is also known that both a CVD-graphite coating and an h-BN coating are effective to induce the mechanism of toughening[1,2]. In the case, of the Si-C-O or Si-Ti-C-O fibers/glass or crystalline oxide matrix composites, it is reported that the formation of the in-situ graphite layer, which is also effective to increase the fracture toughness of the CFCCs, is often found during the fabrication process such as hot-pressing. The lower the crystallinity of the Si-C-O fibers, the higher is the tendency to form the in-situ graphite layer as found by the chemical reaction between the fibers and the glass matrices[3-12]. On the-other hand crystallized stoichiometric 'SiC fibers are attractive for high temperature service because of the higher phase stability compared to the Si¬C-O or Si-Ti-C-O fibers. However, in the previous, studies, the mechanical properties and the interfacial chemical reaction of the crystallized SiC fibers / glass matrix Composites have still been unknown. In this study, a polycrystalline 'sintered SiC fiber-reinforced MAS glass composite was fabricated. The mechanical properties and microstructure were then investigated. The slurry infiltration technique followed by hot-pressing was used to prepare the composites. The formation of the in-situ graphite layer and the relationship between microstructure and mechanical properties at room temperature were examined by the TEM observation of the fiber/matrix interface."

Jan 1, 2000

By Lifeng Zhang

The transport of fluid, heat ,and particles (bubbles and solid inclusions) in flowing molten steel is investigated in steel refining ladles, the continuous casting tundish, continuous casting mold and strand, and steel ingot casting processes. The two-equation k-?? model is used to simulate the turbulence. Multiphase fluid flow is numerically simulated with a Lagrangian-Eulerian approach, an Eularian-Eulerian approach and the Volume Of Fluid (VOF) method. The simulation can predict inclusion trajectories, inclusion removal fraction, free surface waves and other phenomena, which can be used to optimize these important metallurgical operations.

Jan 1, 2006

By Camier R. J, Perry G. J

Extensive deposits of brown coal exist in the Gippsland Basin, primarily in the Latrobe Valley. The total quantities of economically winnable coal in this region of Victoria and in other smaller fields are large enough to adequately assure Victoria's future electricity needs and to also provide large quantities for alternative applications, including liquefaction. As a result of the recent conflict in the Middle East attention has again been focussed on the production of synthetic fuels from coal. There have been many investigations over the years into the production of oil from Victorian brown coal. The purpose of this paper is to summarise the scope, objectives and major findings of these studies, with the emphasis on the direct hydrogenation route for converting brown coal to oil. The principal alternative processes are carboniastion and hydrotreatment of the product tar, or gasification and Fischer Tropsch synthesis of liquids from the product gas. The attractions of Victorian brown coal which have encouraged these studies include: ò the vast reserves of Victorian brown coal and the favourable conditions for low cost mining, ò the high quality of the coal (low ash, sulphur and nitrogen contents), ò the high reactivity of the coal giving high yields of product in hydrogenation to liquid fuels, ò the extensive data base available on the resource and its characteristics, and ò the availability of a skilled workforce and extensive infrastructure in the Latrobe Region to support a major resource development project. These advantages have been partially offset by: ò the high moisture content of the brown coal and the cost of drying, and ò the priority previously given to electricity generation in the allocation of the brown coal resource.

Jan 1, 1992