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By R. Escalera-Lozano, M. Herrera-Trejo, M. A. Pech-Canul, J. López-Cuevas, A. L. Leal-Cruz, M. I. Pech-Canul

"The use fly-ash (FA) and rice-hull-ash (RHA) offers the potential for the manufacture of hybrid Al/SiCp/spinel composites via reactive infiltration, both with recycled aluminum. The main reason behind this statement is the beneficial role that both waste materials play in preventing the degradation of SiCp reinforcements when the composites are processed with aluminum in molten state. Experimentally, MgAl2O4 is formed in situ during the infiltration of SiCp-preforms in the temperature range 1050-1150 oC for 50-70 min in argon atmosphere at a pressure slightly above to that of the atmospheric pressure. Results reveal that both FA and RHA help in preventing SiCp dissolution and the subsequent formation of the unwanted Al4C3; and although FA-composites still might be susceptible to corrosion via Al4C3 -by the interaction of native carbon in FA with liquid aluminum- a proper FA treatment significantly mitigates its deleterious effect. Primary corrosion mechanisms and strategies to overcome the potential degradation effects are outlined.IntroductionOwing to inherent materials characteristics and post-processing complications –such as corrosion damage- development of metal matrix composites (MMCs) from recycling/waste sources might be a challenging task. Fly-ash (FA) and rice-hull-ash (RHA) are two primary waste materials that offer excellent opportunities for the development of Al matrix composites. Due to its singular hollow-spherical shape and low density, FA has attracted the attention of many researchers. For this reason, most of the efforts to develop Al-based composites from waste materials have been centered on the use of fly ash. Extensive research efforts in the use of FA for Al-based composites have been undertaken by Rohatgi and coworkers [1-4]. In addition to lowering costs, incorporation of fly ash into aluminum has been proved to decrease the materials’ density, increase their hardness, abrasion resistance and stiffness [1]. One of the major outcomes from the mechanical evaluation of aluminum composites prepared with fly ash is that related to their compression characteristics. Typical compressive stress-strain curves form A356/hollow fly ash composites show a linear elastic region followed by a plateau (associated to the collapse of the hollow particles), and then an increase in stress, representing densification of the foam. The crushing of the cenospheres in the composites has been related to an enhancement in the energy absorption capabilities of the material and to a better damage tolerance [4]."

Jan 1, 2008

All the Technical PUBlications and Preprints published in 1932 are available at Institute headquarters. They are also on file in public, university and technical libraries and, when so indicated in the list, may be found in the Transactions. Copies of the Technical Publications have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Insti-tute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Copies of Preprints may also be obtained from the Secretary's office. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. Nonmembers may purchase the papers at the prices mentioned. Metal Mining Technical Publi- Title Author Meeting Trans. cation Volume No. and Page* 484-A.45 Propeller Type Mine Fan at Moose A. S. Richardson New York 102, 88. 95 F.52 Shaft. Butte. Montana (13) Feb.. 1932 487-A.46 Progress in the Improvement of Max H. Barber New York. Methods and Equipment at Feb., 1932 Open-pit Iron Mines on the Lake Superior Iron Ranges (9) Pre. Sand Filling through Pipes and Lucien Eaton New York, 102, 33, 41 Boreholes (9) Feb., 1932 Milling And Concentration 445-B.37 Soap Flotation of the Nomulfides Will H. Coghill New York. H.19 (18) J. Bruce Clemmer Feb., 1932 461-B.38 Principles of Flotation—An Experi- I. W. Wark New York. mental Study of the Effect of A. B. Cox Feb.. 1932 Xanthates on Contact Angles at Mineral Surfaces (48) Iron and Steel Division 447-C.81 Electrochemical Potentials of Nitri- Shun-ichi Satoh New York, fied Steels (31) Feb.. 1932 450-C.82 Reaistanoe of Iron-aluminum Alloya N. 9. Ziegler New York. 100, 267. 670 E.143 to Oxidation at High Tempera- Feb., 1932 tures (8) 451-C.83 Pressure Welding of Low-carbon C. H. Austin New York. Steela with Theoretical Con- W. S. Jeffries Feb.. 1932 siderations on the Mechanism of Such Welding (42) 453-C.84 Inclusions—Tbeir Effect, Solubility C.E.Sims New York, 100, 154, 176 and Control in Cast Steel (24) 0. A. Lillieqvist Feb., 1932

Jan 1, 1932

By D. E. Walsh, J. T. Hollow, H. K. Lin, J. L. Oleson

At the Fort Knox Mine, Fairbanks, Alaska, carbon fines are generated during stripping, acid washing and kiln regeneration operations. Because of their gold value, carbon fines are collected by a filter press. Samples of the carbon fines show that they consist of 20% to 30% carbon, 70% to 80% grit and 0.17 to 0.68 g/kg (5.0-19.9 oz/st) gold. About 80% of the gold values in the carbon fines used in this study are in the form of recrystallized free gold grains, with the balance being the adsorbed gold on the carbon. High recoveries of gold and carbon were obtained from the fines in laboratory tests using froth flotation, with a high rejection of the grit. More than 95% of gold and 90% of carbon can be recovered by three stages of gold flotation followed by two stages of carbon flotation. Key words: Gold recovery, Activated carbon, Flotation

Jan 1, 2003

By C. A. Garzonio, A. M. G. Affuso

The paper describes the analyses and the tests carried out on representative slabs of white Carrara marble which have highlighted the correlation between the micro fabrics and physical and mechanical parameters. The aim is to determine the conditions which indicate the triggering and evolution of the deformation phenomena. La note écrit l’analyse et les epreuves effectuée sur un echantillon représentatif de nombreuses dalles en marbrede Carrara. Les études montrent la correlation entre la minéralogie et les paramètres physiques et mecaniques. Le but est déterminer les conditions qui indiquent l’amorçage et l’evolutions des phénomènes de déformation. Diese Arbeit gibt eine Beschreibung der experimentalen Untersuchungen und der Analysen über die Marmorplatten von Carrara. Daraus resultiert, dass die Charakterisierung der Mineralogie und die Porosität der Gesteinsmaterialien die physikalische mechanische Degradation beurteilen und die Krümmungen bestimmen.

Jan 1, 2003

By I Testrow, M Wiggin

Scrutiny of the whole explosives industry has increased as a result of the terrorist attacks on the World Trade Centre and the Pentagon on 11 September 2001 and the bombings in Indonesia, including the Bali bombings last year. This has been highlighted in specific press releases from governing bodies, like the Department of Mineral and Petroleum Resources û Western Australia, on the necessity of being in compliance with regulations for storage of explosives. As a result, audits by inspectors to assess compliance are to be expected. In a proactive move, DynoConsult has assisted several customers through benchmarking current practices, in order to identify any areas of non-compliance to the statutory requirements for explosive storage and security. This paper discusses the outcomes of supplier discussions and customer audits and highlights the implications for the industry.

Jan 1, 2003

Draglines have been a significant part of world open cut mining since the early part of the 20th century particularly for the removal of overburden in the strip mining of coal. Since the mid-1960s draglines have played a major part in the large strip mining coal developments of Queensland and New South Wales.There are now over 60 large draglines operating in Australia ranging in size from 23 to 103 cubic metres bucket capacity, with digging depths to 60 metres, dumping heights to 50 metres and dumping radii to 100 metres. The application of these draglines has progressed through the uncovering of coal in shallow, single seam operations to deep multi-seam operations requiring a greater dependence on pre-stripping activities ahead of the dragline to remove overburden not able to be efficiently handled by the dragline.

Jan 1, 1992

ARTHUR F. BRAID,* New. York, N. Y. (written discussion ?). -I have read Mr. Cain's paper with a very great deal of interest. The subject is one that is worth a great deal of thought and research at this time. It is a well-known fact that the strong affinity of steel or, iron for oxygen is perhaps the main detriment to sound production, and, as the author states, it is-indeed remarkable that today there are no analytical methods in general use in steel works for determining the gaseous con-stituents of steel.

Jan 10, 1919

By Eckley B. Coxe

In making surveys in the anthracite coal regions of Pennsylvania, the ordinary engineer's chain (50 or 100 feet long) is generally used, both above and below ground. Sometimes, where it is difficult to chain, as, for instance, across a chasm, a wire is stretched from one station to the other, the distance is marked on the wire and its length is then measured with the ordinary chain. Having had occasion lately to make some surveys where it was necessary to determine with great accuracy the position of the land or property line, not

SINCE it seems to me that guns are of greater importance in the art of casting than any of the other things that are made by it, and that they require more foresight and care because they need many perfections, I wish now to repeat certain useful and necessary precautions in corroboration, for though I have already spoken to you of them in some detail, the power has not been granted me to pass with one breath completely through a subject with many parts. Therefore it will not be wearisome to you to hear the same thing told again, because it will not be without amplification of some pertinent points. For this reason I have prepared the present discourse, which I have called admonitions. The first of these concerns the making of the pattern upon which the

Jan 1, 1942

By Steven W. Hunt, Ronald E. Heuer, Safdar A. Gill

A 3.3 m (11 feet) diameter, 51 m (168 feet) deep temporary steel casing which had been sunk within glacial soils buckled and collapsed on July 29, 1985. The collapse occurred at the CT-8 Dropshaft site in Milwaukee while two workmen were contact grouting outside the casing in an attempt to stop groundwater inflows through a bottom plug. This paper describes the soil and groundwater conditions at the site, the casing design, the method of shaft construction, and probable causes of the buckling failure. Specific aspects of the paper include: slurry method of shaft excavation and casing installation, soil creep, earth pressure due to three dimensional arching, and buckling strength of a casing surrounded by slurry rather than grout and firm soil. The paper should be of interest to designers and constructors of temporary ground support systems for deep shafts.

Jan 1, 1995

By Carlos Mariotti

Ante la crisis económica de la industria eléctrica en el Perú, el presente texto revisa los obstáculos y se describe la función del Estado en la dinámica del desarrollo eléctrico.

Jul 1, 1959

By Stephen H. Hall

INTRODUCTION At some point in the design and development stage of a mineral venture, the assay laboratory building, its interior layout, and major pieces of analytical equipment must be specified for construction or purchase. Even the most experienced chemist would have difficulty in proposing useful specifications without a good deal of investigation into the kinds of analytical tasks that the laboratory will be expected to address, the probable workload, and the operating time constraints. This chapter will provide a logical approach to laboratory design that starts with such an investigation. Specific examples throughout the chapter are drawn from the author's tenure as Chief Chemist at Barrick Mercur Gold Mines, Mercur, Utah, from 1982 to 1985. It is necessary to understand the nature of a modern production laboratory, and to recognize that its operations bear more resemblance to its parent processing plant than to a research, teaching, or custom analytical laboratory. The assay lab is a processing facility unto itself, where samples and reagents are the raw materials, and assay results are the final product. Its most efficient operating mode is as an assembly line, treating samples in a nearly continuous flow. Nevertheless , there are important differences between the lab and the process plant. The products - assays - are individually unknown quantities until they are "produced.' This can vastly complicate quality control compared to the process plant. Capital costs are general 1 y small compared to the plant, but the ratio of operating costs to capital costs for a laboratory is often very much higher than for the plant. This is due to the labor intensive nature of analytical work. For instance, during Fiscal Year 1984 at Barrick Mercur Gold Mines, labor costs for the laboratory staff represented about five percent of the total labor budget, while the laboratory building and equipment represented only about six-tenths of one percent of the original start-up capital. Failure to recognize both the similarities and differences between laboratory and plant operations is the foremost cause of difficulty encountered in designing a laboratory. The

Jan 1, 1986

By David Marsh, Mark W. Johns

Carbon-in-pulp (CIP) is a preferred method of gold recovery from cyanided pulp. However, the resin-in-pulp (RIP) process is considered to have several advantages for the recovery of gold. Mintek therefore undertook a research programme to develop a commercially-viable RIP process. The MINRIP RIP process and a novel gold­selective strong-base resin, Minix, were developed. The process has been successfully demonstrated at a scale of 100 000 t/month. Continuous countercurrent tests using synthetic solutions indicate that the relative performance of an adsorbent depends on the composition of the solution. Minix resin yielded a higher gold loading than that of carbon, while maintaining an acceptable barren value. Batch tests on a number of gold-bearing materials indicated that Minix has potentially a higher capacity than carbon, and loads gold faster than carbon. An economic appraisal that consolidated the countercurrent results and the economic study indicated that the capital and operating costs of the Minrip process are considerably lower than those of CIP. The amount of the cost advantage depends on the gold content of the feed and the throughput.

Jan 1, 1993

By Vicente Gutiérrez

La actual capacidad de proceso y almacenamiento de los ordenadores personales en la empresa, genera el marco adecuado para el desarrollo de la implantación de medidas de seguridad y productividad, así como el diseño de procesos de manera óptima. Por ello, el presente trabajo señala la aplicación de técnicas de simulación y realidad virtual en la empresa HUNOSA para dar solución a dos problemas diferentes. El primero refiere al desarrollo de una herramienta, donde se busca introducir al usuario en un ambiente que represente el escenario de trabajo, mientras que el segundo, pretende ayudar a la planificación del transporte de interior. Para ello, se desarrolla una aplicación software que permite la configuración de los parámetros de la red de forma sencilla y su posterior simulación en el ordenador.

Jul 17, 2000

SPOT imagery acquired in May 1986 of the areas that include the Dugald River lead-zinc lode, northwest Queensland, Australia and the Ngwenalekau copper deposit, Botswana has been evaluated and compared with LANDSAT MSS imagery of the same areas. The data have been processed using band combinations, band ratioing, principal components analysis and classificatory techniques and the outputs compared with those of geobotanical, geochemical and biogeochemical data as well as geological information. For both study areas the image processing techniques cited have successfully distinguished discrete vegetation associations related to discrete surficial and bedrock geological units; and, notwithstanding the sharp contrasts between the nature of the geobotanical anomalies that in both areas occur over mineralised bedrock in Proterozoic sedimentary sequences, they have successfully identified the areas of anomalous vegetation over the mineral deposits. Greater vegetational and geological detail is revealed than on outputs generated from LANDSAT MSS data [see Cole, 1977, 1982(a) and (b)]. The additional information yielded by SPOT imagery compared with LANDSAT MSS imagery results from its greater spatial resolution - 20 metres as against 79 metres - and from ti fact that the three SPOT MSS spectral bands - 0.50 0.59um, 0.615-0.68um and 0.79-0.89um - respectivelc cover those sections of the electro-magnetic spectrum in which leaf pigments, notably chlorophyll, absorption for photosynthesis and leaf cell structure strongly influence reflectance. This accords opportunities for the detection of reflectance aberrations caused by stress due to drought and/or metal toxicity as well as for the identification of anomalous vegetation communities of moderate sizr These cannot be accurately discriminated on LANDSA I MSS imagery on which only very large geobotanical anomalies like that over the Lady Annie phosphate deposit in northwest Queensland [Cole, 1977, 1984; Cole and Owen-Jones, 19771 can be detected.

Jan 1, 1988

By Terry S. Cory

This report describes the results of a measurement and analysis program to characterize wireless radio transmission in metal/non-metal mines over a wide frequency range from 0.2 - 1000 MHz and over a variety of mine environments. Six mines were chosen based on the relative economic significance of their product to the U.S. economy. Mine types include oil shale, uranium, potash, lead/zinc, copper, and silver. Particular mines were chosen so that the group would embody the most important mining techniques. The results show that transmission at medium frequencies are optimum for wireless mine communications, in agreement with extensive testing previously performed by the authors In coal mines, and that mine-wide wireless systems are feasible with a minimum requirement for new dedicated wiring. At least one need for such a wireless system was identified in each mine visited.

Aug 1, 1981

By Albert H. Chester

During the summer of 1875 I visited some of the iron mines of Houghton County, Mich., and was quite interested to observe the progress made there within a few years. Working in open pits is gradually giving place to underground work in most of the mines where this system is practicable. In some cases, as in the Lake Superior Mine, the body of ore is so irregular, and the deposit so liable at any time to be pinched out, or nearly so, that it. has been found impractical, if not impossible, to lay out any plan for systematic underground work. But in many other mines the deposit is so regular in character, that the work can be laid out in shafts at regular intervals, and a series of 60 feet levels. The Michigammi Mine, opened in 1872, and first worked in 1873, is arranged on this plan, though some quarrying is still done. But the men are being put at overhead stoping as fast as it can be got ready for them, and before long it will all be worked in this way. The New York Mine is undergoing a similar change to the pillar system, and several others have either been changed, or it is about to be done. My principal object in visiting this region was to obtain samples from some of the important mines, so as to be able to answer the question: "What is the average percentage of iron in the Lake Superior ores?" Most iron furnaces work on mixtures of ore, so that it is impossible to tell, from their records, just the percentage in each one.

By K Biegaj

The paper describes challenges the author has encountered on Australian underground gold and nickel mines over the last eight years, when recovering high-grade gold/nickel bearing mine floor material with a mobile supersucker/giant vacuum cleaner and other equipment. Whilst for a number of years the mine floor vacuuming and other mine floor clean-down technologies have been accepted/adopted and are working well in other parts of the world and on the South Australian opal mines, regrettably, they have not yet gained acceptance of mining executives and mine managers of gold and metal mines in Australia, who still elect to leave the never to be recovered gold/metal behind or to put it plainly - waste it.For reporting purposes during the mining process, the portion of gold/metal included in calculation of ore reserves prior to obtaining capital funds for their development, continues to be camouflaged in various reconciliation and call factors. This approach, ie wasting of capitally developed and already broken ore stocks should be viewed by the shareholders as totally inappropriate to say the least, especially with the current gold and other metals prices.The author attempts to provide answers as to why the technology referred to above has not yet been accepted on Australian gold and metal mines and outlines the way forward.CITATION:Biegaj, K, 2012. Why do shareholders and mining executives allow mine managers to leave behind high-grade broken ore underground?, in Proceedings Narrow Vein Mining 2012 , pp 197-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By H. J. Struth

The benefits of proration of oil production were perhaps more concretely realized in 1932 than at any time since the oil industry adopted nation-wide production control. Reduced output of crude petroleum, which brought the daily average of the United States down to approximately 2,000,000 bbl. from a peak in 1931 of more than 2,600,000, had a telling effect on the trend of oil prices. Mid-Continent crude was advanced in price from 776, for 36-gravity oil, to $1.04 a barrel. California crude, of 26-gravity at Signal Hill, moved forward from 736 to 976 a barrel. Pennsylvania crude, the only exception to the upward trend, rose in price from $1.82 per barrel to $2.02, only to react to $1.72. This was due to local conditions which necessitated an adjustment to overcome competition from other areas of the United States. East Texas continued to exert a far-reaching influence on the crude and gasoline market during 1932. Despite the fact that oil prices were advanced in most fields, large quantities of oil were produced in East Texas in violation of state proration orders, and sold in the market at prices considerably below official postings. This created competitive conditions in the gasoline market that were felt by all refining centers of the United States. The quantity of gasoline produced from cheap East Texas crude was not large, but the volume was sufficient to influence prices in practically all sections of the country. Thus, while the industry's' economic situation showed visible improvement statistically, the unreported and unseen statistics originating in East Texas proved to be an insurmountable obstacle to the economic betterment that was otherwise apparently justified. Somewhat surprising to many was the fact that gasoline consumption was maintained within 10 per cent of the preceding year. Domestic consumption showed only a net decline under 1931 of about 8.5 per cent; exports dropped in volume to the extent of about 23 per cent. As a matter of fact, domestic gasoline consumption was only about 1.4 per cent less than it was in the predepression year of 1929. Exports, however,

Jan 1, 1933

By Shawna Munn, Katie Castelo, Dave Wiley

Risk is inherent to work in the field of subsurface engineering, and many contract approaches have become so focused on shedding risk that they leave no room for one of the best tools in our industry, the observational method. Its development in subsurface engineering owes its foundation to Karl Terzaghi and Ralph Peck through their respective works dating back as early as Soil Mech- anics in Engineering Practice published in 1948 and "Advantages and Limitations of the Observational Method in Applied Soil Mechanics" in 1969. Throughout their fundamental works, a strong argu- ment for the observational method is made: "... the potential for savings of time and money without sacrifice of safety is so great that every engineer who deals with applied soil mechanics needs to be informed." (Peck 1969) Not every project will benefit from its use, but in today's risk management focused world, projects and contracts should be set up to allow for its use, while sharing the risk clearly and equitably between all parties. Without a proper contractual mechanism to leverage its use, perceived manage- ment of "risky unknowns" will over- ride substantive application of the method, and significant benefits may be lost as a result. As Terzaghi said, "A vast amount of labor goes into securing only roughly approx-imate values for the physical constants that appear in equations Therefore, the results of computations are not more than working hypotheses, subject to confirmation or modification during construction." It is our collective view that sub- surface engineers should take this task of confirmation and modification seriously. We should use the observa- tional method to derive performance- based designs that deliver design economy, constructability, cost and schedule advantages without sacrificing safety or quality. Collaborative style contracts provide a framework to approach shared risk and opportunity with appropriate incentives for the individual parties.

Aug 1, 2025