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By Robert Hopler

THE KEYSTONE NATIONAL POWDER COMPANY is an Independent organization, incorporated under the laws of the State of Pennsylvania. It has three dynamite mills near Emporium, Pa., with a daily capacity of 165,000 pounds. It maintains branch offices in practically all the largest cities east of the Rocky Mountains, and has distributing magazines located in every section where there is a demand for high explosives, with facilities for wagon deliveries. Our mills are all of modern type and are equipped with the most improved machinery for the manufacture of high explosives. The efficiency of our laboratory in conjunction with the high class of labor employed, has enabled us to put on the market an explosive, the quality of which is the result of extensive research and scientific knowledge. Our modern and complete equipment for harbor and railroad transportation insures our patrons of prompt deliveries, which is an essential feature particularly to contractors and those whose facilities for storage are limited.

Jan 1, 2013

By R. Marandi

The effective removal of heavy metals from aqueous wastes is among the most important issues for many industrialized countries, How ever biosorption, i.e. the uptake of heavy metals by non- living biomass, has gained increased credibility during recent years. Biosorption of Cr(VI) from aqueous solution, on pretreated and immobilized Aspergillus niger was investigated in a batch and countinuous reactors. A.niger biomass pretreated by boiling in 0.5 N NaOH solution for 15 min, exhibited higher Cr(VI) removal capacity than autoclaved biomass. The optimum adsorption pH value observed for Cr(VI) ions was 2. The Cr(VI)removal rate increased with a decrease in pH. The influence of contact time, pH, Cr(VI) concentration, biomass concentration and temperature on Cr(VI) removal were also evaluated. Biosorption of Cr(VI) on pretreated biomass followed the Freundlich and Langmuir adsorption models.In this study A.niger biomass was immobilized in Na-alginate matrix. The biomass beads packed in a column were able to remove metal ions.In this study we used two different flow rate in a column, 1.5 mL/min and 3 mL/min.The breakthrough data obtained for Cr(VI) was adequately by the Thomas and Yan models and the adsorption capacity of the biomass was found to less than the adsorption capacity obtaind in the batch study. When the beads containing biomass become saturated with metal ions, the adsorbed metals were eluted using 0.5 N NaOH solution. Therefor nearly 90% of Cr(VI) was desorbed by NaOH solution.

Jan 1, 2014

By Guosheng Zhan

The Homestake Mine included the open cut and underground workings up to 2,484 m (8,150 ft) deep. The mine ceased mining activities in December 2001 after 125 years of operation. Pumping from the underground workings continued for 18 more months until June 10, 2003. Homestake had completed a comprehensive hydrologic evaluation on post-closure underground flooding prior to the shutdown of pumping. After closure, the mine was selected by the National Science Foundation as the site for the Deep Underground Science and Engineering Laboratory (DUSEL). An interim laboratory facility will be set at the 1478 m (4850 ft) Level. The final facility will be set at the 2256 m (7400 ft) Level or deeper. Pumping from the underground workings began on June 5, 2008 by the South Dakota Science and Technology Authority (SDSTA). During the period of June 2008 through March 2009, the pumping rate increased from 41 L/s (650 gpm) to 81 L/s (1,290 gpm) with an average rate of 60 L/s (950 gpm). As a result, the water level had been lowered more than 95 m (310 ft). It was found that the observed rebound and later decline to date is in close agreement with the model projections. Because of this, the authors of this paper reject claims of a lack of sufficient measurement devices in place and a lack of understanding of the hydrologic system at the Homestake Mine prior to shutdown of pumping in 2003 (Davis et al, 2009). Furthermore, it is believed that this validated model can serve as a useful tool for the SDSTA to manage future underground dewatering for the DUSEL operation. This paper evaluates the hydrologic conditions in the Homestake Mine area and projects the post-closure groundwater rebound and decline due to DUSEL pumping.

Jan 4, 2010

By A. R. Taylor

Low-temperature heat capacities of cesium chloride (7° - 300° K) and cesium iodide (13° - 300°K) were measured with an adiabatic calorimeter. The heat-capacity measurements were analyzed graphically to determine smooth values of heat capacity, entropy, enthalpy function, and free-energy function at 10° K intervals and at 273.15° and 298.15° K.

Jan 1, 1963

By L A. Maslov

We have considered the following characteristics of the crust and upper mantle of the Pacific Belt: seismic wave velocity anomalies, mechanical stress and shear deformation rate fields, heat flow and the pattern of metallogenic provinces of the Belt. It has been noted that there exist certain .regularities in distribution of the above mentioned geophysical characteristics and metallogenic zones within the Belt, displayed by prevalence of the lithophile elements in the Asia-Australian part of the Belt, and of the chalcophile ones within the American part.

Jan 1, 1995

By P. W. Hynes

Tg Soda Ash has operated a shortwall mining system in the Green River, Wyoming trona district since August. 1982. The system has proven to be highly productive. In an effort to reduce the relatively expensive development mining and Improve mine planning flexibility, a method to mine the return air tailgate during the shortwall retreat was tested beginning In April, 1987. As of June. 1988 four shortwall panels had been completed utilizing the advancing tailgate, producing over 815,000 tons.

Jan 1, 1989

By Bradford F. Townsend, Marc R. Kritzer, Michael F. Roach, Dennis Ofiara

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2008

By Dick Minnitt

Large-scale variability in process plants and process control can be identified and controlled through disaggregating the overall variability in a process stream. Conventional statistics and Statistical Process Control (SPC) fail to address the concept of stream heterogeneity, therefore fail to identify and distinguish between the various sources of variability in a process stream. A modified set of 445 data from a process plant is used as an example to explain the benefits of variography in process control. Large-scale variability, usually in the form of product composition cycles and chemical cyclic variations may be manifest throughout a sampling system or a process plant, but this type of variability is most easily discernable in one-dimensional process streams. The Moving Average is a powerful tool for identifying large and small scale variability and cyclical behaviour in process streams, while the variogram is a custom built tool that allows the components of variability to be identified and resolved. The positions in the variogram at which the different variance can be read and the nomenclature of these types of variability is described. The transfer of variances converted to standard deviations to the Control Charts, allows an operator to appreciate the appropriateness of Upper and Lower control and specification limits. The overall contribution of the various sources of variability is represented in a pie diagram.

Jan 1, 2007

By R. G. L. McCready, R. O. van Everdingen, M. Kalin, R. van Everdingen

"This paper is based on data generated between October, 1986 and October, 1989, during the implementation of an Ecological Engineering close-out for a zinc mine in Northern Ontario, where 690000 tonnes of tailings contain 41.1% pyrite and 4.1% pyrrhotite. The objective was to determine rates of sulphide oxidation and iron precipitation in the tailings. Those rates are relevant for the assessment of the long-term effectiveness of biological systems employed in the removal of heavy metals from contaminated drainage issuing from tailings.Data were collected on the topography and stratigraphy of the tailings basin, subsurface temperatures and groundwater levels, and chemical analyses were made of water samples collected from a number of piezometers. The thickness of unsaturated tailings varied widely between individual piezometer locations; annual maxima ranged from 0.67 m to 3.55 m, and annual minima from 0 to 2.68 m. Sulphate concentrations ranged from 36 mg/L to 20180 mg/L; iron concentrations from 0.36 mg/L to 9938 mg/L; and zinc concentrations from 0.33 mg/L to 1123 mg/L.The geochemistry of the piezometer samples suggests that some of the initial Fe content, resulting from metal sulphide oxidation, is subsequently precipitated in the tailings pile and, possibly, in the underlying unconsolidated sediments, probably in the form of iron-hydroxide and Na-jarosite. Other metals such as Zn may be co-precipitated with Fe. The discharge of a portion of these metals to the environment would be delayed by this process. Some of the initial sulphate may also be lost from solution, probably by precipitation of gypsum; approximate saturation degrees for gypsum ranged from -3.27 to +0.47. The precipitated minerals will somewhat decrease the porosity and permeability of the tailings.Sulphide-oxidation rates, calculated using the analytical results and the estimated amount of annual recharge at the tailings site, average 0.0057 mol/kg/yr. Calculated iron-precipitation rates average 0.000386 mol/kg/yr. It is concluded that the characteristics of seepage from mining wastes may change with time, reflecting the solubilization of precipitated secondary minerals."

Jan 1, 1992

In the context of sustainable development, the Minerals Council of Australia (2010) states that 'investments in minerals projects should be financially profitable, technically appropriate, environmentally sound and socially responsible'. In other words, the business of mining can only be sustained if these criteria are met.   Science and technology plays a major role in all four of these criteria. This paper will present the technology and innovation emerging from the Minerals Down Under National Research Flagship which brings together CSIRO and more than ten of Australia's leading universities to work with industry to drive efficiency, productivity and environmental performance. This work is required if the Australian minerals sector is to thrive and continue to deliver national benefit in the face of increased global competition, declining ore grades, depleting ore deposits, increasingly constrained national resources (land, energy, water and people) and changing societal expectations.   Science and technology to reduce emissions and water use, discover greenfields resources, enable deeper mining operations and transform mineral processing are described. Technology is presented as an enabler of sustainability: a means to this end but not as an end in its own right.

Jun 1, 2010

By S C. Dominy

The grade of ore at Marvel Loch mine is directly related to the presence or absence of shear zones and quartz-sulfide-rich hornblende (¦ diopside) veining within areas of plagioclase alteration. An experienced geologist can identify these features in hand specimen. Practical rules have been developed to assist this visual identification. The structural sites and styles of alteration and veining most conducive to gold mineralisation have also been determined. The work has enabled a better understanding of the geological controls on mineralisation at Marvel Loch, and has clarified geological understanding for optimisation of grade control modeling, ore block mark-ups, and minimisation of ore loss and dilution during excavation. In addition to this, it has enabled a detailed understanding of mine scale structural controls, geometry and relative grade relationships.

Jan 1, 2003

By José Calderón

Poderosa tiene sus concesiones en las provincias de Pataz y Bolívar en la región La Libertad y son parte de la zona de amortiguamiento (ZA) del parque nacional Río Abiseo (PNRA) y de la zona de transición (ZT) de la reserva de biosfera Gran Pajatén (RBGP). Esta área natural protegida (ANP) es uno de los dos únicos sitios en el Perú que tienen carácter de patrimonio cultural y natural de la humanidad (doble caracterización dada por Unesco). Poderosa ha firmado un convenio de cooperación interinstitucional con el Servicio Nacional de Áreas Naturales Protegidas por el Estado (Sernanp) del PNRA, el mismo que le ha permitido contar con su asesoría, mejorar los instrumentos ambientales y cumplir a cabalidad los compromisos socioambientales.

May 22, 2019

By J. -P. Tshibangu, A. Vervoort, A. Lavrov

Abstract: The aim of the research presented is to study the effect of complex loading schemes on the fracturing process during loading and/or unloading. A first set of experiments was done using a poly-axial cell. These experiments in combination with numerical simulations showed a difference in micro-fracturing (shear and tensile cracks), but not in macro-failure between various loading/ unloading schemes. The second set of experiments was based on the three-point bending test and several cycles with or without rotation between cycles were applied. If the specimen was rotated by 90° or 180° about its long axis between the first and second cycle, no Kaiser effect was observed. Résumé: Le but de la recherche présentée est d’étudier l’effet de schémas de charge complexe sur le processus de fracturation durant la phase de charge et de décharge. Une première série d’expériences était réalisée utilisant une cellule polyaxiale. Ces expériences combinées avec des simulations numériques ont montré une différence de micro-fracturation (fissures de cisaillements et de traction) pour les différents schémas de charge et décharge, mais en ce qui concerne la macro-fracturation ce n’est pas le cas. La deuxième série d’expériences était basée sur des essais de flexion trois points avec plusieurs cycles, avec ou sans rotation entre les cycles. Si l’échantillon est tourné de 90° ou 180° selon le grand axe entre le premier et le second cycle, l’effet Kaiser n’est pas observé. Zusammenfassung: Der Zweck der vorliegenden Forschung bestand darin, den Einfluß von komplizierten Beanspruchungsschemen auf den Bruchprozess im Laufe von Belastung und/oder Entlastung von Gesteinen zu untersuchen. Der erste hier beschriebene Satz von Experimenten wurde mit einer dreiaxialen Belastungsmaschine angestellt. Diese Experimenten zusammen mit dazugehörigen numerischen Simulationen zeigten Unterschiede zwischen Be- und Entlastungsbeanspruchungen in Bezug auf mikrobruchmechanische Mechanismen (d.h. Scher- oder Zugrisse) an, aber nicht in Bezug auf den Makrobruchprozess. Der zweite Satz von Experimenten umfasste Gesteinsbeanspruchung in mehreren Zyklen von Drei-Punkt-Biegung, indem die Gesteinsproben zwischen den Zyklen um einen angegebenen Winkel (0°, 90° oder 180°) gedreht wurden. Falls die Probe um 90° oder 180° gedreht wurde, wurde kein Kaiser-Effekt im zweiten Zyklus beobachtet.

Jan 1, 2003

By D. R. Kelland

A program has been carried out over the last two years to apply the technology of High Gradient Magnetic Separation (HGMS) to the problem of mineral beneficiation and specifically oxidized taconite iron ores. This program, supported by the RANN division of the National Science Foundation, has consisted of a laboratory program at the Francis Bitter National Magnet Lab- oratory at MIT and a pilot investigation at the Hanna Mining Company Research Laboratory. 1 The laboratory tests were conducted using several batch type high gradient separators and a continuous separator with a rotating matrix which was constructed at the beginning of the program. The high field magnets available at F.B.N.M.L. were used for investigations above 10 kG but most of the test work was performed in the range of this field value. Ore samples were contributed by several iron ore companies and consisted of oxidized taconites having goethite and hematite as their principal components.

Jan 1, 1975

By J. R. Giegerich

THE problem of dust control in metal mines has, of late years, received considerable attention. In 1932, a detailed study of dust conditions at the Sullivan mine was undertaken and, while there are no actual data available regarding conditions prior to that date, there has unquestionably been a great improvement as a result of the investigation and of the preventive methods adopted. In attacking the problem, three main factors were considered: first, and most important, how to prevent dust from being formed; second, how to depress or collect it if formed; and third-if unable to accomplish these-what precautionary measures must be adopted to prevent inhalation of this dust. Seven distinct methods of dust control are now practised at the Sullivan. Six of these are employed underground; they are tabulated below in the order of their relative importance. The seventh method is used in the crushing plants on the surface. (1) Improved ventilation (2) General use of water sprays and atomizers (3) Curtailment of secondary blasting during shift hours ( 4) 100 percent wet drilling-primary and secondary (5) Wearing of protective equipment (6) Change from carbide to electric lamps (7) Installation of dust collectors

Jan 1, 1936

By C. Sui, J. E. Nesset, M. Li, J. Y. Kim, S. L. Chryssoulis

"A plant study of zinc rougher flotation at Brunswick Mining was conducted using lime, soda ash and a combination of both as the pH modifiers in order to establish the effects on sphalerite and pyrite kinetics and mineral selectivity. The plant sampling and analysis was augmented by surface analysis using TOF-LIMS, SEM and XPS as well as fundamental precipitation and surface-charge studies in the sphalerite Ca/C03/S04 system.The results revealed the important role of carbonate ions in cleaning the sphalerite surface for effective activation by CuS04 to occur, and the beneficial role of combined soda ash and lime in increasing pyrite and galena depression.1.0 IntroductionThe studies reported in this paper were initiated as part of an investigation into the causes of a particularly pronounced seasonal deterioration in metallurgical performance at the Brunswick Mining concentrator during the summer of 1995. The concentrator treats a complex base metal ore having a typical feed composition of 9.0% Zn, 3.5% Pb, 0.4% Cu and 100g/t Ag at a current throughput of 9,000 TPD, although at the time of the problem in 1995, the average production rate was closer to 10,500 TPD. Zinc, lead, copper and bulk (zinc-lead) concentrates are produced with overall metal recoveries of 86% zinc, 63% lead, 60% copper and 60% silver; results which are typical of the lower recoveries associated with fine-grained, highly complex VMS and SEDEX type deposits. The main economic minerals of interest are an iron-containing (7% Fe) sphalerite, galena and chalcopyrite with the main diluent (about 60% wt) being pyrite.Figure 1 shows a simplified flowsheet of the Brunswick milling circuit while the seasonal decrease in summer metallurgy in 1995 is illustrated in Figure 2. Of significance is the rapid drop in copper and lead recovery in June while there is an apparent delay until late August-September before the zinc deterioration reaches its lowest point. A more typical seasonal effect within the experience of the authors is the reverse of the Brunswick situation, namely an improvement in summer performance thought to be associated with improved differential flotation kinetics during warmer weather leading to better mineral selectivity. The historical Brunswick experience was particularly severe during the summer of 1995 with estimated incremental losses of $10 Million for this period. The potential of the very significant economic benefits to be gained from understanding and hopefully improving the annual drop in performance led to an investigation involving the minesite metallurgical group, the Noranda Technology Centre (NTC) as well as researchers in Professor Jim Finch's group at McGill and the surface analytical services and interpretive skills of AMTEL."

Jan 1, 1998

By R. G. Aspden, D. A. Colling

THE {120}(001) texture has been reported in near 50 pct Ni-Fe alloys <0.004 in. thick1,2 and in copper 0.014 in. thick.3 This texture is one of two types of secondary recrystallization textures observed to replace a cube texture matrix and is desirable in Fe-Ni alloys because of its unique magnetic characteristics.1,2 However, the conditions for and mechanism of the {120}(001) formation are not well understood.3 During an investigation of the influence of alloying elements on the magnetic characteristics of 49 pct Ni-Fe alloys with a sheet thickness of 0.014 in., we have observed the growth of {120}(001) secondaries when strong deoxidizers such as aluminum and calcium were present. It is believed that this observation in unique and provides additional insight with regard to the mechanism for {120}(001) texture formation. Three alloys were prepared with electrolytic iron and nickel and contained a nominal 49 wt pct Ni. Alloy A was a straight binary Fe-Ni alloy, whereas intentional additions of 0.013 wt pct Ca to alloy B and of 0.59 wt pct A1 to alloy C were made. Ingots were forged at 1100 C, hot-rolled to 0.150 in. gage, pickled, and cold-rolled to 0.014 in. Standard U-shaped magnetic test specimens were punched, deburred, sprayed with MgO, and annealed in ~50°C dew point hydrogen. Textures were identified with the aid of etch pits, the

Jan 1, 1970

By Andrew J. Brennan, Jonathan A. Knappett, Lewis Hamilton, Michael J. Brown

"Abstract This paper investigates the compressive behaviour of screw piles in sands and the key design parameters which control this. These types of foundation elements have typically been used as screw anchors onshore (i.e. for their tensile capacity), but there is increasing interest in their potential use as compression piles for supporting offshore marine renewable energy (MRE) devices (e.g. wind and tidal turbines) in deeper water. For such foundation applications, the compressive capacity is as important as the tensile capacity and is not well understood, particularly in cohesionless soils which are a likely seabed condition in MRE applications. A 1-g laboratory study was initially conducted on small scale model screw piles in sand beds of various relative density between 25 – 88%. These experiments were used to validate a Finite Element (FE) model having a stress-dependent constitutive model, making it useful for future up-scaling of the pile size for field applications. Following validation, the FE model was used to conduct a parametric study on the effects of flange spacing ratio (s/Dflange) and flange to shaft diameter ratio (Dflange/Dshaft). By using a validated FE model for this study, it was possible to observe the failure mechanisms (through the shear strain distribution) within the soil and correlate these with the pile capacity. This information was then used to comment on the most optimal (cost-effective) pile design for supporting compressive loads. This study represents a key step towards producing design tools appropriate for the design of screw piles in MREapplications.IntroductionAs defined in this paper, screw piles consist of a central small diameter hollow steel shaft, around which thin circular steel flanges run. Their principle of operation is that the flanges are spaced so as to trap the soil between them, thereby acting as an equivalent solid pile of the outer flange diameter, with a fully-rough ‘shaft’ interface (as shearing is soil-soil). One of the most important design decisions relates to the spacing of the flanges – if the flanges are spaced too far apart, then the soil will not be effectively trapped and the pile have a lower axial capacity and stiffness (controlled by the shaft friction along the central shaft and the bearing resistance arising from the individual flanges; If the flanges are spaced too close together, then there are potentially flanges which are not contributing to the pile capacity, therefore making the pile more expensive than it needs to be."

Jan 1, 2014

By John P. Turner

The behavior of tieback retaining walls depends on many factors, including soil properties, groundwater conditions, construction sequence, spacing and stiffness of tiebacks and soldier piles, tieback loads, and others. The primary design considerations for tieback walls are 1) adequate stability and 2) limiting wall movements. Traditional design methods rely on apparent earth pressure diagrams and experience to predict the forces which must be supported by the tiebacks to provide adequate stability. The required soil properties depend upon whether the soil is sand, soft clay, or stiff clay. Design to limit wall movements is more difficult and the usual approach is to design the wall with an adequate factor of safety for stability and then evaluate wall movements during construction through the use of load tests on individual tiebacks and monitoring of wall movements by optical surveying, slope indicators, and extensometers. If excessive movements are likely to occur, it is often not known until construction is well underway. This approach is reflected in the fact that few tieback walls fail due to a lack of adequate stability, while most litigation involving tieback wall performance is related to excessive movements. Much progress has been made in recent years in methods for predicting the movement of all types of insitu retaining walls (Clough et al. 1989, Clough and O&apos;Rourke 1990). These methods are based upon both experience and analytical methods. This paper reviews the methods currently available for evaluating both the stability and movements of tieback retaining walls. Case histories involving excavations constructed in the downtown Seattle area are used to evaluate the applicability of the available methods to Seattle conditions and to illustrate the importance of soil behavior in tieback wall performance.

Jan 1, 1990

By R. K. Datta, T. S. Davis

YVO4:EU, excited under 3650A radiation, shows a marked increase in total brightness with in~rease in temperature. At 25°C the response to 3650A radiation is about 48 pct of its maximum response which occurs at about 350°C, Fig. 1. In an attempt to explain the phenomenon, one of the present authors&apos; (R.K.D.) investigated the diffuse reflectance spectra of the phosphor at different temperatures (up to -150°C) and was unable to observe any significant change to which the increased brightness could be reasonably ascribed. Since then diffuse reflectance spectra at elevated temperatures have been obtained in this laboratory using an improved device. A significant decrease in the diffuse reflectance of a phosphor in the ultraviolet region—especially in the longer wavelength region—at -300°C has been observed. The purpose of this note is to describe the device used for high-temperature reflectance measurements and to explain the increased brightness of YVO4:Eu phosphor at elevated temperatures under 3650A excitation. Experimental. YVO4 and YVO4:Eu samples were prepared as previously described.&apos; The elevated-temperature reflectance spectra were obtained with a Cary 14 spectrophotometer equipped with a diffuse reflectance accessory and a ring collector. CaF2 was used as the standard. The cell used

Jan 1, 1969