Search Documents

By G. W. Jones

Among its investigations into the prevention of waste in production and use of oil and gas, the Bureau of dines has made considerable study of the efficient utilization of gasoline and by-product distillates in motors, this being done chiefly by measuring and analyzing the exhaust gases therefrom. A number of reports3 of a highly practical nature have been published and are available on this subject. The results of these tests have shown that the average motor vehicle wastes approximately 30 per cent of the heat value of the fuel used, as incomplete combustion products - carbon monoxide, hydrogen, and methane, These unnecessary large heat losses are mainly due to improper carburetor adjustment, and by proper¬ly adjusting the carburetors for maximum power and efficiency a large part of this heat loss can be eliminated. This in turn results in an increased mileage per gallon of fuel used.4

Jan 1, 1924

By A. J. Basu

An overview of the evolution of computerized mine planning and design has been given, emphasizing the need for a knowledge-based system for planning and design of underground coal mines. An outline for the development methodology and procedure has been provided. Problem structuring guidelines have been used to incorporate intelligence and integration to the design modules. A skeletal model for a mine planning and design expert system has been prescribed, and the development process has been documented in detail. A feasibility prototype has been developed to test the structure of the skeletal model and to ensure completeness of the design process. The feasibility prototype development and its contribution toward proto typing has been addressed in this paper. At present, prototype development is underway. The prototype is expected to be avail-able for testing and implementation in early 1991.

Jan 1, 1991

By M E. Pierce, T V. Garza-Cruz

Rock mass strength and brittleness generally have a significant impact on both cavability and fragmentation. Variability in these properties across a panel or block footprint is of particular interest because stronger units have the potential to significantly impact cave shape. This paper describes how FLAC3D™ was used to examine the impact of variability in rock mass properties on predicted cave performance to aid in assessing potential risks associated with the proposed design.A case study orebody was subdivided into a number of domains to reflect the heterogeneity of the rock mass at the scale of a proposed inclined cave. The results suggest that the presence of stronger units has the potential to impact cave shape significantly in the southern half of the cave footprint and could increase the potential for cave stalling at shallow depths. If this unit is stronger and less brittle than expected, an overhang is predicted to develop in the southern half of the inclined cave at depth. The effective hydraulic radius is significantly reduced due to the overhang in the south, and the cave could eventually stall at shallower depths in the north.CITATION:Garza-Cruz, T V and Pierce, M E, 2016. Impact of rock mass strength variability on caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 359–368 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By R. E. Head

"The microscopic work described below was engaged in primarily into ascertain the approximate proportions in which the copper sulphides existed in the ore examined, and by a comparison of the results obtained from a study of both head are tailing samples to supply data which might be of value in treating the ore by flotation. Incidentally, the physical characteristics and association of the sulphides were noted in order to determine the possible relation or bearing of these features on the present conditions of treatment. Since the copper in the ore occurred as three distinct sulphide minerals - chalcopyrite, chalcocite, and bornite each containing copper in different proportions, there appeared to be little or no possibility of obtaining the desired information by chemical methods of determination.Type of material examinedThe material examined was in the crushed condition and was said to be representative of the flotation feed or heads and the resulting tailing. No hand samples of the ore were examined nor any account taken of the physical condition and association of the minerals in place, because the possible value of the analytical results depended on conditions as they existed in the crushed ore. As the problems under consideration dealt only with the sulphide minerals, especially those of copper, the products from screen sizing were concentrated by hand panning and the gangue discarded. The concentrate obtained consisted almost entirely of the sulphide minerals, since the panning had been very carefully done. The object of this procedure was to obtain a sufficient quantity of high-grade sulphide material, from the sample of each screen size selected for examination, to permit its being so prepared for examination as to be representative of the physical characteristics exhibited by a large number of sulphide grains from each respective size, In the tests and investigations carried on by the company' treating the ore the following sizes had been used in tabulating data and basing conclusions:+48, +65, +100, +150, +200, and -200. These same sizes were used in the microscopic investigation, since the results obtained thereby could be most readily utilized for comparison with the results obtained in previous experimental work, together with deductions based on actual concentration of the ore on a commercial scale."

Jun 1, 1921

By James D. O, DeLa&apos

Multicomponent materials are common in nearly all areas of materials science and technology, yet the use of phase diagrams to represent these complex systems is hampered by the requirement of three or more dimensions for explicit graphical representation. In the present work, the "solid-modeling" capabilities of a computer aided design (CAD) system have been applied to the representation of three-dimensional phase diagrams. Relevant phase diagrams for a hypothetical quaternary eutectic system were constructed and used to demonstrate the capabilities of the technique. These capabilities lead to relative ease of phase diagram construction and improved access to qualitative and quantitative information. Results of this work are contrasted and compared to previous efforts toward computer ,representation of phase diagrams. It is concluded that solid-modeling of three-dimensional phase diagrams can be used to advantage in both education and research.

Jan 1, 1991

By H. D. Kline

This publication describes mining and milling methods and costs at the Madison mine of National Lead Co., St. Louis Smelting & Refining Division, in the Fredericktown district of southeast Missouri and is one of a series prepared by the Federal Bureau of Mines on methods, practices, and costs of mining and milling throughout the United States. The are bodies of the Madison mine are known for the complexity and diversity of their are minerals. Sulfides of copper, nickel, and cobalt occur in commercial quantities with lead sulfide, which is the most valuable metallic mineral in are bodies of the Bonne Terre formation in southeast Missouri. Several attempts were made by various operators to mine the complex ores and separate the sulfide minerals before 1927 when National Lead Co. became interested in the Fredericktown district. Operating then as the St. Louis Smelting & Refining Co., the company began mining and milling ores from the Madison mine in 1944 and has operated continuously since then. A recently built refinery produces copper, nickel, and cobalt metal from a concentrate containing iron sulphides and small quantities of copper, nickel, and cobalt sulphides.

Jan 1, 1961

Ilmenite (FeTiO3) is the primary global source of titaniumdioxide which is commonly used as a whitening agent in papermanufacture and a pigment in paint manufacture. In WesternAustralia ilmenite is processed by the Becher process (Becher,1963, Becher et al, 1965) where ilmenite particles are feddirectly into the furnace with coal and heated to form acomposite of elemental iron and TiO2. The mechanism of thecarbothermic reduction of ilmenite has been extensively studied(Grey, Jones and Reid, 1973; Jones, 1973; Grey and Reid, 1974;El-Tawil, Morse and Francis, 1993) and is reasonably wellaccepted.

Jan 1, 1997

By G. T. Lineberry

There is a critical need for effective instructional materials at the university level and for an upgrading of mine safety and health in the mining engineering curriculum. A fundamental approach to mine safety and health is recast into the familiar 3 E's: engineering, education, and enforcement, in that order. Each is briefly reviewed and their interdependence emphasized. A unique philosophy for successfully integrating safety and health principles into the mining engineering curriculum is offered. The concept of textbook ?tailoring? is discussed and defended, permitting rapid assemblage and synthesis of existing educational materials. Final recommendations are made for a u, comprehensive approach to mine safety and health education in the undergraduate curriculum.

Jan 1, 1987

By Francis Church Lincoln

I. Situation and Surroundings, The Promontorio mine is situated at the northern end of the Sierra San Francisco de Coneto, in the town of Promontorio, Partido of El Oro, State of Durango, Mexico. As shown in the sketch-map, Fig. 1, the nearest railroad station is Chin-acates on the Mexican International Railroad, 82 miles north of the city of Durango. The mine is 16 miles north of the sta-tion by air-line. It is reached by means of a good wagon-road which first crosses the Guatimapé Plain, passing the ranches of San Antonio and San Julian, to Estacion—a distance of about 15.5 miles—and then entering the mountains crosses the Sierra to Promontorio—a further distance of 11.5 miles— making in all a distance of 27 miles by road from railroad to mine. Promontorio is just beyond the summit of the range, at an elevation of about 8,000 ft. above sea-level, or 1,350 ft. above the Chinacates station. The Castillo de San Francisco, the highest peak in the Sierra, has an altitude of 10,000 ft., and the Promontorio road crosses the summit of the ridge at an elevation of 9,000 ft. by a pass just below this peak known as the Puerto del Almagre. The Promontorio mill is situated at Santa Inés, 2 miles by tram or 3 miles by wagon-road to the north of Promontorio and about 600 ft. lower. The Sierra San Francisco de Coneto decreases in height towards the north and west till it comes to an end at the Mel-chor Arroyo on the ranches of Melchor and Ramos. Beyond this arroyo another range, the Sierra de la Candela, begins. In the vicinity of the Promontorio mine the hills are very rugged and the surface is furrowed by ravines which contain running streams during the rainy season-—July, August and

Jan 1, 1908

By J S. Moema, R Paton, J Zimba

Today, most organisations are familiar with the pressure to increase their effectiveness and efficiency, regardless of the nature of their business. Cost cutting and increased productivity are the main themes of many initiatives to ensure the profitability of operations and, ultimately, shareholder satisfaction. It is well known that the cost of comminution to liberate minerals such as gold from their respective ores is a major expense for mines. Comminution costs consist predominantly of grinding balls and electricity. However, there are no national or international standard specifications for grinding balls û on which a single mine may spend several million dollars per month. In addition, in the past mines generally did not specify the minimum requirements when purchasing grinding balls from suppliers. The result is that every supplier has its own grinding ball recipe (regarding chemistry and heat treatment), and is under no pressure to implement a quality assurance plan to ensure that a consistent product is delivered. The resulting variation in the quality of grinding balls leads to increased steel consumption rates and hence increased milling costs. A more stringent quality plan will generally not be welcomed by suppliers since this may entail further investments and/or reduce the production rate. In a sense, suppliers benefit from poor quality grinding balls as this leads to increased sales. Perhaps the main problem is a lack of understanding of the factors that influence grinding ball performance. This paper will describe the factors that influence the wear rate of grinding balls from both a microstructural perspective and a mill perspective. In addition, some insights are provided on the different grinding balls available and ways that users can verify their quality.

Jan 1, 2007

By A. J. Kraemer

For a number of years the Bureau of Mines has conducted semi-annual survey to determine the changes in the characteristics of the rotor gasoline being sold in the United States. Certain cities have been decided upon as points of origin of samples. Tare choice of these cities has been governed by their situation as the representative of a more or less definitely bounded marketing territory. Samples have been taken on or about the fifteenth day of January and July of each year. In the collection of the samples an attempt has been made to get a representation of the important types of motor fuel being sold, and also to tame into consideration the proportion of tie total consumption that is supplied by the different marketers. It is therefore felt that the survey affords a reliable indication of the quality of the gasoline being sold throughout the United States at the time of sampling. The figures in Table I, below, were obtained by averaging the end points of the least volatile and most volatile samples of gasoline. For example, of 850 samples analyzed in 1919, the 10 per cent (85 samples) having the highest end points, and the 1C per cent having the lowest end points were averaged. These averages are represented in the table as the "Maximum 10 per cent" and the "Minimum 10 per cent", respectively. The same scheme was used in the succeeding surveys.

Jan 1, 1925

By Sam Tour

WHAT is a die-casting and what is the die-casting industry? From the literal translation of the words "die" and "casting"' one concludes that a die-casting is a casting made in a die. The casting may be of any metal or alloy or, for that matter, may be of some nonmetallic material capable of being cast, such as plaster of paris or glass. The die may be of any material that will take successive casts so it need not necessarily be metallic in nature. The term "die-casting," therefore, is indeed broad, though in practical usage it has come to mean the casting of metals and their alloys in metallic molds or dies. Even this limitation of the term leaves -a broad field, for castings may be made in a number of different ways. For example, the molten metal may be allowed to run into the die by gravity it may be sucked into the cavity of the die, it may be forced to take the contour of the cavity in the die by centrifiugal force, or it may be forced into the cavity under hydrostatic pressure. In England, castings made by practically all of these

Jan 1, 1935

By E E. Hall, S, E D. Thimons, R J. Timko

The heart of mine ventilation science and technology is the protection of the life and health of the miner. Lung diseases that result from overexposure to various mine aerosols can largely be prevented by maintaining concentrations below prescribed limits. Maintaining safe aerosol concentrations depends, in part, on our ability to know what mine aerosol concentrations are in a timely and accurate way. The Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH) has been developing several new tools to help miners monitor respirable coal dust, silica and diesel particulate matter. This paper will discuss three main topics. First, the latest results of the person wearable dust monitor (PDM), developed by Rupprecht and Patashnick under CDC contract. The PDM was tested side-by-side with conventional samplers at a number of US coal mines and results indicated that the PDM was comparable to conventional samplers. Second, improvements to the dust dosimeter monitoring technique that includes a new pump with built-in pressure transducer and algorithm to convert differential pressure to dust concentration have shown good precision. Third, advances in the use of the detector tube technique to monitor tailpipe diesel emissions and ambient diesel particulate matter show that strong correlations exist between differential pressure measurement and elemental carbon in the samples.

Jan 1, 2005

By Emmanuel Henry

Hanging wall deformation monitoring at the Kiruna Mine is a major concern for Luossavaara- Kiirunavaara AB (LKAB) since underground production is deepening towards the Kiruna Town. In the quest for more effective monitoring techniques, LKAB decided to evaluate satellite-borne Synthetic Aperture Radar (SAR) interferometry?s ability to monitor ground subsidence by generating continuous deformation maps from satellite radar images. While adopted by other geoscience-related industries, SAR interferometry is still relatively untested in the Mining industry. This paper describes how subsidence is actually monitored on the Kiruna Mine?s hanging wall and gives an insight on SAR interferometry?s principle. The encouraging results are discussed as well as the technique?s benefits (continuous deformation mapping, low cost, fast, etc) and limitations (sensitivity to snow and vegetation cover).

May 1, 2003

By Guy Archambault, Réal Daigneault

"Un trait marquant du cadre tectorwstratigraphique de la Sous-province de l'Abitibi est la présence de nombreux couloirs de déformation d’extension régionale et sub-concordants au grain stratigraphique. La présence de grandes masses granitoïdes qui perturbent l'allure du grain tectonique est typique de la partie nord de la Sous-province de l'Abitibi. Des rides E-W constituées de complexes plutoniques précoces forment des reliefs structuraux agissant comme des moles résistants qui interfèrent avec la déformation régionale.Deux types de couloirs de déformation sont distingués, les couloirs de bordure et les discontinuités structurales. Les couloirs de bordure représentent des auréoles de déformation élevée qui s’accompagnent généralement d’un métamorphisme au faciès amphibolite. lls suivent /'interface entre les roches granitoïdes et les assemblages supracrustaux. Ces couloirs sont de puissance kilométrique et sont confines, surtout au sein des roches vertes, a l’interface des complexes granitoïdes d’importance. La limite entre la Sous-province de l'Opatica et les roches supra crustales de l'Abitibi est caractérisée par un important couloir de bordure issu possiblement d'un chargement tectonique irrégulier et concentre lors du raccourcissement horizontal.Les discontinuités structurales sont des failles ductiles qui se propagent surtout en direction E-W mais avec des variantes de directions SE et NE. Les discontinuités E-W se caractérisent par la présence d'une linéation d'étirement à fort angle de chute. Les discontinuités SE sont caractérisées par des linéations d'étirement horizontales et directionnelles et les mouvements observes sont system attiquement dextres. Les discontinuités NE sont des failles à comportement beaucoup plus fragile et se distinguent par des composantes de mouvement senestre. Elles sont tar dives par rapport aux discontinuités E-W et SE et ne représentent pas la symétrique du système SE.La combinaison des systèmes E-W et SE décrit un motif anastomose a l' échelle régionale. Les failles ductiles se rejoignent defaçon asymptotique, isolant des blocs peu ou pas affectes par la déformation. L'anastomose est un phénomène qui se produit a toute échelle et est reliée principalement aux Mt érogénéités et aux anisotropies 1) des forces agissantes (champs de contraintes régionale et locale) et 2) de la réponse del' empilement supra crustal (compositions différentes, fabrique initiate, propriétés mécaniques variées, niveaux d'altération).Dans le but de respecter un raccourcissement horizontal N-S, différents modelés sont proposés; ils mettent en cause soit une transpression dextre, soit des failles inverses réactivées en failles décrochèrent dextres soit des failles de chevauchement redressées."

Jan 1, 1990

By Donald O. Capstick

[ ]

Jan 1, 1983

By A. J. Lyon, J. B. Johnson, Samuel Daniels

The wrought alloys of aluminum with small amounts of copper and of magnesium have, with the development of the automotive and aircraft industries, sprung into prominence through the medium of duralumin; but the cast alloys remained in the background because their possibilities in the heat-treated condition were either not recognized or not fully investigated. In 1919, the Bureau of Standards published a preliminary survey1 of this field, which pointed out that, in general, the ultimate strength and the percentage of elongation of the alloys of aluminum with and without magnesium could be improved by so simple a treatment as heating at 932' F. (500" C.) for 2 hr., cooling in air, and aging at room temperature for several days. British investigators, too, working with chill-cast material, found that" considerable improvement in the mechanical properties of copper-aluminum alloys may be obtained from suitable heat treatment applied to castings."' Jeffries and Gibson8 made the first contribution to the literature dealing exclusively with the heat treatment of sand-cast aluminum-base alloys, describing the effect of small additions or of combinations of copper, magnesium, and iron on the response to a short heat treatment comprising heating at 932" F. in a nitrate bath for 1 hr., quenching in fish oil, and reheating at 300' F. for for 1 hr. Their results disclosed the facts that the ultimate strength and the percentage of elongation of sound alloys were usually, and quite uniformly, improved by heat treatment; that with the iron content ranging between 0.36 and 0.88 per cent. and the silicon content between 0.24 and 0.60 per cent. the effect of increasing the copper content (Tables 10

Jan 1, 1925

By F. N. Shi

Ore breakage characterization plays an essential role in the design and optimization of comminution circuits. Recently, the JKMRC comminution research team has developed a Rotary Breakage Tester (JKRBT). The JKRBT uses a rotor-stator impacting system, in which particles gain a con-trolled kinetic energy and are impacted against the stator, causing particle breakage. The first unit of industrialised JKRBT was installed at the Anglo Research in South Africa in March 2007, and five more JKRBTs are currently being fabricated for some of the world?s major mining companies. In addition to the JKRBT, an improved breakage model has been developed at the JKMRC, which more accurately describes the effect of specific energy, particle size and incremental breakage caused by repetitive impacts. The validation outcomes show that the JKRBT, together with the new breakage model, generate statistically similar breakage parameters to the traditional drop weight tester (DWT), but with significant advantages over its predecessor. The limitations of the DWT, specifically its lack of precision of the energy input, the lengthy time required to run individual tests and the challenges en-countered in testing small particles, have all been overcome by the JKRBT. The recent developments in the JKRBT and the new breakage model offer several prospective applications. These developments have the potential to revolutionize the ore breakage characterization in the years to come.

Jan 1, 2014

By S. Kelebek, E. Yalcin

This paper reports bulk flotation characteristics of a pyritic gold ore sample from the Barry District, Quebec using isopropyl and amyl xanthates. The ore sample was highly floatable with particles showing tendencies for self-aggregation that was most apparent in the first stage of flotation. A possible reason for this is discussed. The gold concentrate grade-recovery performance with respect to the particle size is presented for the rougher-scavengers as well as for the cleaners. The effects of copper sulphate as an activator, fuel oil and NaSH as a sulphidising agent are discussed along with the recovery by size behaviour.

Jan 1, 2011

By E. J. KENNEDY

THE 142D MEETING of the Institute is rapidly shaping up with splendid prospects of a strong technical program and the lighter side of this annual occasion amply provided for. The date is February 20 to 23. The technical sessions will be held in the Engineering Societies building; the smoker-dinner, the informal dance, and the annual reception and dinner, at the Commodore Hotel, Monday, Tuesday and Wednesday respectively. The news to date on the technical side is as follows: Mining Methods-Subsidence The Mining Methods Committee has prepared an interesting program which will be divided into two sessions to be held early in the week. At the first there will be papers on mining methods and development, including a description of the "Sinking and Equipment of No. 2 Shaft at Minas de Matahambre," by Dudley D. Homer and R. H. Cromwell. They describe in considerable detail the equipment used and the practice followed in sinking this important shaft, giving detailed costs and performance figures. Hoist¬ing ?arrangements and mining practice at the "Red Ore Mines of the Woodward Iron Co. at Bessemer, Ala.," are described by Tenny C. DeSollar, superintendent of mines, in a second paper. At this session of the Mining Methods Committee, H. M. Roche and R. E. Crockett, of the Committee on Eastern Magnetite Mining and Milling Methods, will present their paper, "Iron Ore Mining at the Scrub Oak Mine." This mine is in the highlands of New Jersey about 40 miles west of New York City. Prof. Robert K. Warner of Yale University will present a paper on "The Selection of a Mining System," which should have an interesting discussion. Pierre R. Hines, of Portland, Ore., will present, with stereopticon slides, his paper on "The Owyhee Tunnels, U. S. Reclamation Project, Owyhee, Oregon," describing one of the recent irrigation undertakings.

Jan 1, 1933