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Following is the personnel of the various society and national committees on which the A I M E is officially represented United Engineering Society Officers of the Board, 1921 JOHN VIPOND DAVIES, President CALVERT TOWNLEY, 1st Vice-president ALFRED D FLINN, Secretary WILLIAM L SAUNDERS, 2d Vice-president JOSEPH STRUTHERS, Treasurer Finance Committee House Committee CALVERT TOWNLEY, Chairman ALFRED D FLINN, Chairman GEORGE H PEGRAM . H S CROCKER WILLIAM L SAUNDERS BRADLEY STOUGHTON GEORGE M BASFORD CALVIN W RICE F L HUTCHINSON

Jan 1, 1923

A poured slag bottom is universally considered to be the best type bottom for copper reverberatory furnaces. It is impervious to molten matte and ready for immediate use.When molten slag is not available a monolithic silica bottom is the second best; such a bottom has been adopted at Mount Morgan. The laying of such a bottom is a phase of smelter construction on which so little real information is obtainable that a day to day record of such a recent example as Mt. Morgan's 19 ft. x 40 ft. reverberatory may be of interest. The work was done under the direction of E. Pesout, of McGill Smelter, Nevada. PREPARATION OF THE BOTTOMA 26-inch bed of closely packed firebrick with sand-filled joints was first laid on the clean, dry concrete foundation and the whole dried out by small fires maintained on the brickwork for several days. Ninety tons of silica sand was meantime thoroughly dried and stored in clean drums. This sand must be low in FeO and CaO and contain about 95% Si02 , the majority of which should be present as tridymite. This form of silica shows little expansion at high temperatures, for it is the form stable between 870° and 1470° C.Its presence thus minimises disturbance to the bottom by the expansion which, during the burning in, would mark the transformation of quartz to tridymite.

Jan 1, 1939

By W. A. Longacre

IN the geophysical exploration program of the Cleveland-Cliffs Iron Co. on the Marquette Range of Northern Michigan, the vertical intensity magnetometer has been used to obtain magnetic anomaly maps of large areas. A network of magnetic base stations has been established and the relative vertical intensity at each station measured carefully with respect to a prime base. In the search for the relatively nonmagnetic soft red hematite ore, the magnetic exploration is indirect, involving the study of dikes, faults, contacts, and other structural features. It was found that the, magnetometer, adjusted to a scale value of approximately 40 y per scale division, was satisfactory for this type of exploration, although many magnetic anomalies were encountered that required the use of auxiliary magnets.

Jan 10, 1951

By George Wilson

When pumping abrasive slurry mixtures, special attention must be given to pump design and construction. The second article in this two-part series describes some design features to consider when selecting centrifugal slurry pumps. Hydraulic Design Most centrifugal pumps are conventionally designed to achieve the desired hydraulic performance at the highest efficiency and lowest cost when handling clear fluids in reasonably clean environments. Manufacturing limitations are not imposed on the configuration of the pump, since conventional materials such as cast iron, bronze, and stainless steel are used. Manufacturers and buyers usually select the highest specific speed commensurate with the lowest cost attainable. Part life is almost infinite. When a centrifugal pump is designed for slurry service, the important factors in pump design are wear and materials of construction; size and efficiency assume lesser importance. The pump must operate at low rotational speed and the impeller has to be a truly radial flow design. These factors immediately determine that the pump must be of a low specific speed design in the range of 600 to 1800. The specific speed is a type number that is constant for all geometrically similar pumps; it designates the geometry of the impeller and casing. [ ] where n = rpm, Q = flow (US gpm), H = total head (ft), and Ns = specific speed. Since wear is a function of velocity it can be shown that for a given head and capacity, wear will increase with increased Ns. Centrifugal Pump Casing The casing has a profound effect on performance. If designed incorrectly it can destroy a large part of the energy given to the flow by the impeller, resulting in low efficiency, high hydraulic forces, and excessive wear on both the casing and impeller. In a conventional spiral volute, the static pressure around the impeller is uniform only when there is a free vortex velocity distribution in the volute, i.e., when the spiral flow from the impeller coincides with that of the volute spiral. This occurs only at the best efficiency point (BEP), between the pump's best operating zone and over capacity zone. Departure from the free vortex velocity distribution in the volute at partial or over capacities produces circumferential pressure gradients at the impeller periphery, which is directly proportional to the specific gravity of the mixture being pumped. At partial or over capacities, the flow will not tolerate the abrupt deflection at the tongue and severe energy losses and wear are created near the casing throat and on the impeller. Concentric and semi-concentric volute designs produce uniform static pressures at the impeller periphery and make the pump, much less sensitive to "off"' BEP operation. Hydraulic forces and wear are considerably reduced-eliminating the tongue prevents abrupt deflection of the flow, turbulence is minimized, and the velocity in the casing volute and throat is reduced. Good efficiency is sustained over a wider operating hand. Casings of this design are easy to cast. • Spiral volute (conventional)-Radius to the outer periphery of the casing and the volute area constantly increases. • Semi-concentric casing-Radius to the outer periphery of the casing and volute area remain constant within a certain angle. • Concentric casing-Radius to the outer periphery of the casing and volute area remain constant through 360°. The degree of concentricity must be reconciled with efficiency, hydraulic radial load, and wear for each specific speed chosen. Up to 1200 Ns the casings can be fully concentric without sacrificing too much efficiency. Above 1200 Ns, the casings can be semi-concentric. The angle of concentricity

Jan 10, 1981

By Kathleen Lagnese, Srikanth Muddasani, Kashi Banerjee, Carla Robinson

"Mine water generated from underground coal mining operations contains both dissolved and particulate solids. Dissolved solids primarily consist of sodium, calcium, magnesium, potassium, chlorides and sulfates. When discharged to a receiving stream without treatment, these constituents create a potentially toxic environment for aquatic life.A case study is presented to discuss how a centralized treatment plant treats mine water from six locations to meet discharge limitations for chlorides. Located in West Virginia, this facility consistently achieves less than the National Pollutant Discharge Elemenation System (NPDES) permit limitation of 218 mg/L chlorides in the discharge while generating almost zero liquid waste. The dissolved solids concentration in the influent ranges between 5,000 and 10,000 mg/L, with chloride concentrations of 1,000 to 2,000 mg/L and sulfate concentrations of 2,000 to 6,000 mg/L.The mine water is treated using advanced treatment technology to produce clean water for discharge or reuse. The treatment process comprises aeration, softening, filtration, reverse osmosis (RO) reject softening, evaporation, crystallization, final effluent remineralization and sludge dewatering. The solid waste generated in the treatment process is landfilled on site. The leachate is sent back to the facility’s thermal treatment process. Because no liquid waste leaves the property, this plant is termed a zero liquid waste (ZLW) facility.The advanced water treatment system was built to meet a new 218 mg/L regulatory limitation imposed by the West Virginia Department of Environmental Protection for chlorides discharged to surface waters. The system is designed to treat a maximum flow of approximately 795 m3/h (5 million gpd) of mine water. The treatment process utilizes RO membrane treatment to achieve the effluent criteria, and evaporation and crystallization technology to manage the RO concentrate from the water treatment process. As a result, the system produces clean water for discharge while generating zero liquid waste. The effluent water can be used for industrial purposes or discharged to a receiving stream. A water impact index (WIIx) study indicated that discharge of this high-quality water into the Monongahela River watershed may improve the water quality for downstream water users. The waste produced in the treatment process, including softening sludge and salt, is disposed of in an onsite landfill. Currently, the plant is treating at an average flow of 490 m3/h (3.1 million gpd) of mine water with an average influent chloride concentration of 1,530 mg/L and an average effluent chloride concentration of 11 mg/L."

Jan 1, 2014

By J H. Park, M J. Lee

Because the environmental problems are occurred by greenhouse gases such as CO2, the industries have tried to increase electric motor efficiency to reduce CO2 emissions. A core material of electric motor is high-silicon electrical steel. The ferrosilicon (FeSi) alloy, a raw material for the production of electrical steel, affects the electric properties of silicon steel. The main impurities such as Ca, Al and Ti make inclusions or precipitates that causes core loss. The slag treatment has been widely used to remove impurity elements. Thermodynamic principles for the refining of several impurities, specifically Ca and Al, have been investigated, whereas thermodynamic behaviour of Ti has not been fully understood yet. Therefore, in the present study, the titanium distribution ratio () between ferrosilicon and CaO-SiO2-Al2O3 slag system at 1773 K was investigated. The results show that is influenced by both the basicity and stability of titanium ion in the slag. Specifically, exhibits a minimum value at about C/S=0.7 indicating a shift in the titanate structure unit from [TiO5]-square pyramid to [TiO4]-tetrahedron because of lack of Ca2+ ions in a C/S<0.8 region, contributing to an increase in titanate capacity and .

Jun 19, 2024

By AIME AIME

BORN a Chicagoan, on Aug;. 31, I879. Oscar Johnson lived in that city until young manhood. As a youth delivering newspapers he set his sight on the l university of Chicago and at sixteen years of age he began working summer vacations in the foundry of the Pullman Company. Misfortune came to his family during the summer of 1898 when tuberculosis took his only sister and brother. His mother, apprehensive of Oscar&apos;s health, urged him to try the West at least for awhile. So late summer found Oscar in Salt Lake City, employed by the Trent Engineering & Machinery Co. At that time it was busy building equipment for use in the war with Spain. Though he did not know it then, Oscar war was laying the groundwork for his present membership on the Mining Equipment Industry Advisory Committee of the W.P.B., a post which keeps him commuting between Denver and Washington.

Jan 1, 1944

By E. C. Dominguez, H. B. Scharf

THE Sparrows Point plant of Bethlehem Steel Co., southeast of Baltimore, is the largest Bethlehem plant, with an annual rated capacity of 6.2 million ingot tons. There is considerable diversity of product, but a high percentage is sheet, tin plate, galvanized sheets, and rod and wire. The large amount of light-weight end product requires a number of pickling installations that necessarily consume large quantities of sulfuric acid. In the coking operations sulfuric acid is also consumed in recovery of ammonia as ammonium sulfate and in treatment of recovered light oil derivatives. Total sulfuric acid consumption in the plant is currently approaching 10,000 tons per month, of which 55 to 60 pct is required for pickling. In 1951 the acute sulfur shortage caused grave concern as to future sulfuric acid supply for the Sparrows Point plant. Raw materials for acid making were already at hand in the form of hydrogen sulfide and pyrites sufficient to produce nearly half the sulfuric acid required at that time. It was also known that the Bethlehem mining activities would produce additional pyrites in the future. Late in 1951 Bethlehem management decided to build a 250-ton sulfuric acid plant at Sparrows Point to utilize these raw materials. The plant was built and put in operation in May 1953. The steel plant has expanded considerably since 1951, and it is now necessary to operate the acid plant far over rated capacity in order to supply plant demand. Production of acid in 1954 amounted to 93,000 tons. Raw Materials for Acid Making: Coking operations at Sparrows Point produce a residual fuel gas in large quantity which has a net heating value of 525 to 545 Btu. Prior to 1950, plant surplus coke oven gas was sold to the local utility company. In

Jan 1, 1957

By Edwan Anderson Ariza Echeverri

O processo de estampagem a quente também conhecido como press hardening, é um dos métodos mais utilizados atualmente pela indústria automobilística para produzir aços de alta e ultra alta resistência. Esse processo é principalmente usado em peças relacionadas à segurança passiva e à resistência ao impacto, tais como pára-choques e barras de proteção laterais. O uso desse processo aumenta a segurança dos passageiros e reduz o peço do veículo e, portanto, o consumo de combustível. No presente estudo, amostras de aço ao boro foram deformadas a quente, não isotermicamente, a 850ºC e 750ºC em 30% a uma taxa de 0,5s-1. As microestruturas obtidas após deformação a 850ºC foram quase totalmente martensíticas, diferente das amostras deformadas a 750ºC, onde houve uma diminuição da fração volumétrica de martensita e um aumento da fração volumétrica de ferrita. Portanto, a deformação aplicada a 750ºC resultou em uma diminuição dos valores de microdureza. Desta forma, tornou-se possível investigar a influência da deformação em alta temperatura na transformação martensítica, na fração volumétrica de ferrita e nos resultados de microdureza.

Aug 16, 2017

By F. Calizaya

This study summarizes the results of various numerical and laboratory experiments per-formed to study the effect of airflow recirculation on gas concentration. The numerical exercises were carried out on a simulated mine ventilation net-work. The laboratory experiments were conducted at the Mackay School of Mines&apos; airflow monitoring system in Reno, Nevada. In both cases, the airflow was recirculated through the system by means of a main fan and a set of booster fans. The booster fans were positioned to produce two types of recirculation: In line and Cross-cut. For each type, various recirculation conditions were generated by changing the booster fan pressure. During each test, the gas emission rate at the simulated working face was kept constant. The study illustrates the conditions under which controlled airflow recirculation may be used to solve a district ventilation problem.

Jan 1, 1991

By R. Dawson Hall

R. DAWSON HALL (The Coal Age, New York City) : Mr. Chairman and gentlemen: I do not feel that I have anything in particular to say. I have not prepared anything for an occasion such as this. I just came from New York City, and as one man said to me today, "That is not any recommendation in particular." (Laughter.) In answer to your request for a few remarks of a timely character I would say: One of the possibilities in the Rocky Mountain Region coal mines is the use of steel arches, posts and straps. The timber of the region seems unusually subject to dry rot and does not last long, especially in those places as in southern Wyoming, where the mine atmosphere is likely to contain a large quantity of carbon dioxide. It is true that, in many mines, much care is taken to drive out this gas and to arrange that the timber will have the fresh air that will prolong its life, but despite such provision much timber is subjected to speedy rot. Steel has made rapid progress in England, Germany and France and is recognized as an economy, not an extravagance. Frequent replacement of rotting wood and removal of broken rock are a source of great waste, risk and inconvenience in operation that together spell great cost. The very dryness of the mines and the lack&apos; of acid water are favorable to the use of steel where support of roof or sides is necessary.

Jan 1, 1932

By J. B. Littlefield

This study is one of at number conducted to determine the concentration of dust in the air during the complete cycle of operation in wet drilling; information as to various factors connected with, drilling in mining operations is considered to be of definite value in the control and prevention of air dustiness, and it in particularly desirable to ascertain whet features of present-day wet-drilling operations in mine work contribute to dust disease and to remedy deficiencies when they are found.

Jan 1, 1938

By Bradley S. Van Gosen, Anjana K. Shah, George M. Bedinger, Donald I. Bleiwas, Karl J. Ellefsen

"Ancient and modern coastal deposits of heavy mineral sands (HMS) are the principal source of several heavy industrial minerals, with mining and processing operations on every continent except Antarctica. For example, HMS deposits are the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, obtained from the minerals ilmenite (Fe2+TiO3), rutile (TiO2) and leucoxene (an alteration product of ilmenite). HMS deposits are also the principal source of zircon (ZrSiO4), from which zirconium dioxide (ZrO2) is obtained for uses mostly in refractory products. Sometimes monazite [(Ce,La,Nd,Th) PO4] is recovered as a byproduct mineral, sought for its rare earth elements, and thorium (Ault and others, 2016; Sengupta and Van Gosen, 2016; Van Gosen and Tulsidas, 2016).HMS are sediments containing dense (heavy) minerals that accumulate with sand, silt and clay in coastal environments, locally forming economic concentrations of the heavy minerals (Fig. 1). Economic (mined) HMS deposits include Holocene sediments on modern coasts, such as examples in India and Brazil, as well as coastal deposits formed by transgressions and regressions of the seas during intervals in the Quaternary, Tertiary and Cretaceous, such as in Australia and the southeastern United States. Economic deposits typically contain heavy-mineral concentrations of at least two percent. Individual heavy minerals are commonly defined as minerals with a specific gravity greater than approximately 2.9 g/cm3. These minerals are generally resistant to chemical weathering and physical degradation and thus survive well in fluvial and coastal environments. Heavy minerals in coastal HMS deposits may include, in order of general abundance, ilmenite, leucoxene, rutile, magnetite, zircon, staurolite, kyanite, sillimanite, tourmaline, garnet, epidote, hornblende, spinel, iron oxides, sulfides, anatase, monazite, cassiterite and xenotime. Of these, ilmenite, leucoxene, rutile and zircon are the primary economic minerals. Garnet, monazite, cassiterite and xenotime are occasionally recovered as byproducts. The heavy minerals as a suite typically make up no more than 15 weight percent of a deposit and usually much less. Quartz and clay minerals form the bulk of the sediment. The geology of HMS deposits and examples of significant districts are summarized in Van Gosen and others (2014) and Hou and Keeling (2016)."

Oct 1, 2016

By R K. Dayal

Many transport tunnels show distress after few decades of construction. Owing to exorbitant cost of replacement, rehabilitation of tunnels has become inevitable and rapidly gaining attention/significance worldwide. This paper discusses the detailed planning and design of remedial measures for repairs and rehabilitation of the twin tube highway tunnel in India, at an elevation of 2200 m constructed approximately 38 years ago. The tunnel length is 2547 m having 30 m2 cross-sectional area of each tube. The tunnel is lined in stretches, totalling 60 per cent lined and the remaining portions are unlined. The tunnel has developed acute problems of rock falls, water leakage, distressed pavement and icicle formation resulting in slow movement of vehicular traffic which has also increased. Suffocation inside the tunnel caused deaths due to inadequate natural ventilation, hence artificial ventilation was deemed necessary and was provided in the restricted 28.5 m2 cross-sectional area of tunnel. The paper would be useful for planners, designers and construction engineers for setting future trends.

Jan 1, 1999

Access to secure and reliable water resources is fundamental to the minerals industry. In recognition of that requirement, and cognisant of extensive contemporary public water debate and reform initiatives in Australia, the Minerals Council of Australia (MCA) approached the Ministerial Council on Mineral and Petroleum Resources (MCMPR) proposing the establishment of a Joint Working Group to prepare a framework of strategic principles to ensure responsible water management at a site and corporate level, manage risks and identify opportunities. The Framework provides high-level guidance on issues that should be addressed in water decision making across Australia in relation to mining and associated processing operations. It identifies principles and objectives for adoption in four areas, viz: valuing water, strategic water planning, implementation, and engaging stakeholders. Given the high level nature of the Framework, and its national application, it does not seek to replicate detailed guidelines already widely available in each state and territory on operational water management practices and associated regulatory issues at mine sites. The Framework includes a series of case studies from across Australia that demonstrate where strategic thinking, wise water management and close consultation with stakeholders has delivered better water use, more profitable operations and excellent community/stakeholder relationships. The Framework was formally launched on behalf of MCMPR by the Western Australian Minister for Resources at the MCAÆs Sustainable Development Conference in Perth in October 2006. No full paper available for this extended abstract

Jan 1, 2006

By E. P. Pfleider, O. Rellensmann

In the May 1959 issue of [=] the authors reported on the gyrotheodolite as used for determining azimuths in surface and underground work. Further research has led to the development of a new type of gyro instrument, the band-suspended gyro attachment, which is essentially an upset gyro attached to the top of a theodolite. The new gyro attachment is light enough to be mounted on any angle-measuring instrument if the design of the telescope standard permits. Gyrotheodolite units have been used to transfer meridian lines underground in the Coeur d&apos;Alene mining district, although they have not been used extensively in the U.S. In other parts of the world, however, they have been adopted as the standard surveying instrument by mining engineers.

Jan 3, 1968

By Zay Jeffries

AMONG the various metals with low specific gravity, two, aluminum and magnesium, are used in the nearly pure state or as bases for light-weight alloys. Although the production of magnesium is only about one-twenty-fifth that of aluminum, a higher percentage of its output is used in the transportation industry than that of any other metal. The per-centage varies from year to year but, on the average, more than three-fourths of the magnesium production has been used for this purpose. In the United States, about 40 per cent of the aluminum production is used for transportation purposes. It seems obvious that equipment demanding repeated movement with need for rapid acceleration and deceleration should be as light in weight as the economics of engineering materials will permit. There are, however, differences of opinion with reference to both the economics and the engineering aspects of this subject. Tables 1 to 7 inclusive relate to the principal light-metal materials currently used in the transportation industry. These, with the accom-panying titles and footnotes, are in the main self-explanatory. Although the variations in mechanical properties can be easily seen from the tables, it should be kept in mind that the values given are for ordinary tempera-tures and that the changes in properties with temperature are not the same for the different alloys. Also, the corrosion properties cannot be deduced accurately either from the compositions or from the physical properties. Again, certain of these alloys are used because they possess desirable combinations of properties not listed in tine tables, including heat conductivity, coefficient of expansion, machinability, ease of casting or working, light reflectivity, anodic coating characteristics, etc. These, together with variations in prices, must be given careful analysis to effec-tively utilize the light alloys. Some of the alloys listed in the tables are new and some are old, but all are standard. Even the older alloys are available in new shapes and larger sizes than heretofore, and all are used in the transportation industry in structures of new design. Certain of the applications of specific alloys will be touched upon in the following brief history of the use of the light metals in transportation.

Jan 1, 1936

The transition from low stress to high stress conditions is a challenge eventually faced by most mines in Australia that extend to depths greater than (generally) about 1000 m. In areas with strongly adverse &apos;stress versus depth&apos; gradients, such as some parts of Western Australia, significant stress-related problems have occurred at depths as shallow as 300 m below surface. The actual depth at which the &apos;transition&apos; occurs is a function of the local pre-mining stress field, the strengths of the various rock types hosting the deposit and the layout and sequencing adopted in the mine. Stress-related damage can result in increased support costs, and delays associated with rehabilitation and disruption to production. In the worst case, where strong seismicity and associated damage occurs in active mining areas, &apos;exclusion&apos; zones and &apos;re-entry&apos; protocols may be required. These can severely disrupt production. A key aspect of managing the transition is the recognition of the onset of stress-related ground behaviour. Damage mapping can be used to develop understanding of the relationships between mining activities and the local and regional response to them. Carefully documented case histories provide a basis for calibrating numerical models. This paper discusses some of the typical styles of ground behaviour observed in higher stress conditions in underground mines. A simple damage classification scheme is described to assist in &apos;damage mapping&apos; of mine tunnels. An example of damage mapping is presented to illustrate an approach commonly used for recording stress-related damage.

Nov 25, 2010

By Benito Barbabela Silva, Michel Garant, Mathieu Dubé

Pellets market challenging scenario has stimulated pelletizing experts to pursue innovative alternatives to process development in order to increase pellets competitiveness vis-à-vis sinter. When it comes to indurating process, pelletizing productivity is still limited and its OPEX inflated by the lower input of carbon into mixes due to quality impairment caused by magnetite formation in pellets core. This obstacle led to the rethinking of carbon distribution strategy within the green balls. To achieve such purposes, COREM through its precompetitive research program dedicated to its members, has proposed the layered pellets®, a two-stage balling technology. Balling in disc and pot-grate tests in COREM’s pilot plant were carried out to proof the concept, support the arising technology and evaluate its potential. According to first results, while CCS strongly improved, tumble and abrasion indexes as well dynamic LTD must be further investigated. Tests on four classes of equivalent carbon content pellets to evaluate layering strategy gave very good perspectives concerning the increase of productivity, and the reduction of fuel consumption and GHG emissions.

Oct 1, 2019

By J. V. Richards

(Canal Zone Meeting, November, 1910,) THE Altar district, State of Sonora, Mexico, is for the most part a desert with but little rain-fall and few running streams. On account of this scarcity of water it is necessary for the natives to " dry-wash" the placer-gravel, and the object of the present paper is to describe some of the more common Mexican dry-washing devices. My observations were confined to a property known as Las Palomas placers, 15 miles from the Gulf of California and about 150 miles south of the United States border; a brief description of which property may be of interest as illustrating what is, perhaps, a typical Sonora dry placer. It is said that as long as a century ago the Yaqui Indians discovered rich cement-gravel, known as argo masa, at Las Palomas, and that there has been a more or less steady production of gold from the property ever since. The argo masa is a fairly-coarse gravel, the pebbles being quite firmly held together with a lime cement. Gold is scattered through this cement in particles ranging from fine specks to pieces several grams in weight, and occasional large nuggets are encountered. The contents vary so widely that it is difficult to estimate the average value, but returns of from $10 to $50 per cubic yard are common, and it is doubtful if the Indians considered anything less than from $4 to $5 a yard as "pay dirt." This argo masa occurs in channels varying in thickness from a few inches to several feet, and in width up to 300 ft.. These channels are continuous and are probably ancient stream-beds. They are for the most part covered with an over-burden of a more recent gravel, varying from 30 to 50 ft. thick, and the fact that this over-burden contains values as high as $1.50 per cubic yard, and yet was not worked by the Indians, shows that their idea of what constituted pay-ground was high.

Apr 1, 1911