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A special meeting of the Institute, at which the Institute of Metals Division will join with those members who are most interested in iron and steel, and in coal and coke, will be held in Milwaukee, Wis., October 8 to 11, 1918. The technical program is as follows: INSTITUTE OF METALS DIVISION Tuesday morning, October 8: The Metallography of Tungsten, by My Jeffries. (Bulletin No. 138, p. 1037.) The Constitution of the Tin Bronzes, by S. L. Hoyt. Paper, title not given, by C. H. Mathewson. Notes on Babbitt and Babbitted Bearings, by Jesse L. Jones. (Bulletin. No. 140, p. 1397.) Oxygen and Sulphur in the Melting of Copper Cathodes, by S. Skowronski. (Bulletin No. 135, p. 645.) The Relation of Sulphur to the Overpoling of Copper, by S. Skowronski. (Bulletin No. 135, p. 651); with discussion by Philip L. Gill. (Bulletin. No. 140, p. 1156.)

Jan 9, 1918

By D. V. Fites

The ripper is not a new tool. In fact, it dates back as far as the Roman Empire. The Roman's ripper-mounted on wheels and shaped something like a plow-was pulled by oxen and was used to loosen the earth for the shovelers and basket carriers building the Appian Way. There are records of rippers being used in this country in railroad construction between 1860 and 1880. The tractor-mounted ripper, introduced a little over ten years ago, extended the capability of the ripper because of greatly improved maneuverability and the additional weight which could be brought to bear upon the ripper tooth. Increases through the last ten years in tractor weight and horsepower further increased ripper capability until now, in some geographic areas, hardly any rock is unchallenged by them.

Jan 12, 1967

By R. K. Mehta, C. W. Schultz, R. R. Mallepali

Stirred ball mill feeds used for ultrafine grinding applications require a fine size separation step to avoid overgrinding. This paper presents the selectivity curves obtained for oil shale and complex sulfide ore using a 460-mesh (30-µm) Derrick vibrating screen. The selectivity curves generated from the experimental data show increasing selectivity with larger size for the oil shale but not for the sulfide ore. These unusual selectivity curves are similar to the mechanical air separator, fishhook selectivity curves described by Luckie and Austin. A two-stage, in series, classification model describing the fishhook selectivity curve has been used in proposing the classification mechanism for fine vibrating screens when a heterogeneous, multicomponent sulfide ore undergoes size separation.

Jan 1, 1994

By Edward R. Mueller

The application of a simple analog computer constructed in a home workshop has registered a 10% to 15% gain in truck productivity at the mammoth Pima mine, located 35 km (22 miles) south of Tucson, Ariz. The newly installed dispatching board enables the truck control foreman to make near-optimum dispatching decisions and to monitor each individual truck, identifying any that are off schedule.

Jan 8, 1977

By R Uken G P Whitmore

The coastal dune cordon of northern KwaZulu-Natal is amongst the highest in the world reaching heights in excess of 180 m and up to 2 km in width. It comprises a complex system of Quaternary stacked dunes of various geomorphologies, types and ages. The dunes contain economic heavy minerals which are currently exploited ~20 km north of Richards Bay. Although mining of these ore sands has been in operation for the last two decades, little work has been undertken on the clay-fraction (

Jan 1, 2001

By M. R. Moon

The fire at Wilberg Mine in 1984 reached the surface resulting in the failure of the vertical ledge forming the roof and entrance for three main intake portals. The fallen material was covered with a concrete cap to seal the air from the mine. As the mine was recovered and ventilation pressure was placed on seals on the perimeter of the fire area, the concrete capped rubble proved ineffective. Due to the steep and rugged terrain and the inaccessibility to the portals from underground, horizontal holes were drilled into the portal entries and three seals were placed remotely. The seals, in conjunction with pressure balancing the seals around the perimeter of the fire area, resulted in the control of the mine fire.

Jan 1, 1994

A new two-metre column self-heating test procedure has been developed at the University of Queensland, which clearly shows the hot spot development phases that take place in bulk coal self-heating. The column results provide a more reliable indication of the self-heating propensity of coal than small-scale index tests. At the same time, off-gas evolution patterns associated with hot spot development are obtained, including the recognition of hydrogen evolution from oxidation at temperatures less than 80¦C. Subtle differences in off-gas evolution from self-heating between gassy and gas-drained coal are also apparent. This new approach to coal self-heating assessment offers an opportunity to further the understanding of the complexities of spontaneous combustion and will enable more accurate risk assessment for the coal industry.

Jan 1, 2005

By N. N. Clark, C. M. Atkinson

Pachuca tanks are used widely in the mineral industry for leaching and mixing operations. An analysis has been presented previously to predict circulation of homogenous slurry in Pachuca tanks with full height draft tubes. However, settling of solids causes deviation from the homogenous case. Circulation of settling slurry in a Pachuca tank is modeled and shown to be a function of settling velocity, solids fraction, solid and liquid density, air flew rate, and tank dimensions. The pressure balance is shown to be very sensitive to these parameters, especially at low slurry velocities. Equations for predicting the air requirements in Pachuca tanks containing settling solids are presented.

Jan 1, 1988

By Owen F. Jensen

CONSTRUCTION of a ground-water supply includes many operations, which do not end with completion of facilities. Evaluations must be made of the quality of water in various areas and the history of production. Following an analysis of geologic, hydrologic, and chemical data there must be an exploratory drilling program and a study of resulting information. When the well is completed a continuous survey of operating records and basic data is necessary, since designs for future wells are varied as more data becomes available for those already completed. As the following discussion must be limited to a single undertaking, the customary procedure will be outlined for development and construction of a ground-water supply in which more than three wells are involved. Parts of this procedure are applicable for all ground-water supplies.

Jan 11, 1954

By John C. Edwards

A computer code for laminar, steady-state, incompressible, two-dimensional flow developed by Gosman (2)3 was modified by the Bureau of Mines to calculate shock (minor) loss at the intersections of ventilation ducts. Turbulent flow was simulated using laminar flow equations and an appropriate wall shear stress. Results of the calculation showed good agreement with the experiment.

Jan 1, 1977

By J. M. Cabal, M. Chica Olmo, J. P. Laille

One of the main goals of a simulation of a coal deposit mining is to predict a series of parameters considered by the miner to be useful, e.g. ash content, sulphur content, seam thickness etc). The idea is to simulate different ways of mining a multi-seam brown coal deposit (the Mine Puentes de Garcia Rodriguez deposit, ENDESA, Spain ), which is exploited by several bucket-wheel-excavators (BWE) . Two mining models are used: a geostatistical model which provides a numerical way of re- presenting the three-dimensional ore-body, then a deterministic model, consisting of simulating the technical aspects of the mining. The main purpose of this simulation is to show how the mining operations can be reproduced using these two techniques.

Jan 1, 1983

By Ferris E. Sainsbury

As most mining companies utilize contractors rather than in-house drilling departments, it is difficult for most mining engineers to become familiar with drilling techniques This chapter will explain the various drilling options available to the mining industry through the services of a drilling contractor. It will also suggest improvements in program planning and specification writing by the mining company representatives to enable them to derive maximum benefit from the contractor.

Jan 1, 1979

By L. W. Saperstein, MJ. Carlson

With the goal of improving the strength characteristics of pneumatically emplaced material used for localized subsidence control, the binding additives fly ash, bentonite, and portland cement were examined for their effect on the support capabilities of coal refuse. It was found that, within certain concentration ranges, all three offered some increase in the ultimate strength of the backfilling mixture. However, portland cement gave the greatest percentage increases. Selection of the appropriate backfilling mixture will allow for the most economical and efficient subsidence control when pneumatic stowing is employed.

Jan 1, 1990

By W. A. Rickelton, A. J. Robertson

The ability of triisobutylphosphine sulfides to selectively recover silver from acidic sulfate solutions containing zinc and copper is described. Selectivity is explained in terms of the concept of hard and son Lewis acids and bases. Silver is stripped from the solvent using a novel strip feed (thiosulfate salt), and the recovery of metallic silver from the strip liquor by electrolysis or cementation is suggested. The high selectivity of extraction for silver and the utility of the stripping reagent are demonstrated in continuous, countercurrent, mini-plant tests. Important reagent properties, such as hydrolytic stability and low aqueous solubility, are discussed.

Jan 1, 1988

By J. E. Lawver, B. J. Clingan, R. E. Snow

Response surface methodology is a well-known and powerful technique for determining optimum conditions in flotation systems. One disadvantage is the onerous task of the numerical calculations and curve plotting. This paper describes a system in which the investigator simply selects the range of several flotation variables after which the design of the experiment, data analysis, generation of response surface equations, and response surface plots are automatically carried out using a digital computer and a computer-driven curve plotter. Several typical response surfaces of important variables in phosphate flotation are presented as examples.

Jan 8, 1979

By Stanley M. Miller

The probabilistic nature of appropriate geologic variables can be included in analyzing the stability of potential slope failure modes. Random variables in the two-dimensional plane shear analysis of a specified structural discontinuity include the shear strength and waviness angle of the discontinuity and, in some cases, the rock mass density. Estimated probability density functions that describe these random variables are combined by Fourier analysis to produce an estimate of the safety factor probability density function, which appears to approximate a gamma distribution. The probability that sliding will occur along the specified structure is equal to the area under this density function where the safety factor is less than one.

Jan 1, 1982

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. STANLY A. EASTON, -Chairman. FREDERIC KEFFER, Vice-Chairman. LYNDON K: ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. D. C. LIVINGSTON, FRANK A. ROSS.

Jan 7, 1916

By Jorge Medina R.

"Después de dos años de preparación para adoptar un sistema de gestión de calidad de acuerdo con los requerimientos de la norma ISO 9001:2000, la Planta LESDE de Southern Perú Copper Corporation en Toquepalay Cuajone acreditó su sistema de gestión de la calidad a su producto (cátodo de cobre) en la auditoría de certificación. En ese sentido, el presente trabajo señala la aplicación del sistema de gestión de calidad ISO 9001: 2000 en cátodos electrowon en la SPCC a través del diagnóstico, compromiso, planeación, capacitación, documentación, implementación, auditorías internas, preauditoría, certificación, visitas de seguimiento, participación del personal y las optmizaciones esperadas respecto a este tema. Asimismo, es importante integrar la gestión de la calidad en seguridad, salud, y medio ambiente y así lograr la certificación ISO 14001:2000."

Jul 31, 2003

By Sterling G. Valentine

The annual .use of large quantities of sulphurous iron-ores (over 1,500,000 tons in the United States) has led to a search for the best methods of desulphurization, in order to make this material more available for the manufacture of a good quality of pig-iron. Although such ores can be used raw in small amounts, they must be previously roasted if they are to constitute the entire ore-charge of a furnace.

Jan 1, 1890

By R. Hogg

The various sub-processes which, together, make up the unit operation of froth flotation all depend on the characteristics of the feed solids, the solution phase, the air bubbles and the mechanical/hydrodynamic action of the machine. Characterization is obviously necessary for evaluation and process control, but the relationships between characteristics and process response are often unclear. A model-based characterization scheme is proposed in which material and system characteristics are evaluated in the context of simplified models for the individual subprocesses. The general basis for such an approach is discussed using the process of particle attachment and the influence of mineral liberation as examples.

Jan 1, 1989