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By Gae On Kim, Ki Baik Kim, Suk Hoon Kang, Tae Kyu Kim, Sanghoon Noh

"Advanced radiation resistant oxide dispersion strengthened steel (ARROS) is being developed as a fuel cladding tube material for future nuclear reactor system applications. The research activities consist of advanced radiation resistant ODS steel development and fabrication technology development of ODS steel structural components. One candidate material with a chemical composition of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3and was selected as representative materials, and this material was named as the advanced radiation resistant ODS steel (ARROSTM).On the basis of this ODS steel composition, an optimized fabrication process of structural components such as plates, sheets and tubes has been established through various process conditions in mechanical alloying, hot/cold working, and heat treatment processes. These R&D activities are expected to contribute to the realization of ODS materials in the future.INTRODUCTIONA sodium-cooled fast reactor (SFR) is being developed at the Korea Atomic Energy Research Institute (KAERI) with a view to economics, safety, reliability, and sustainability. The prototype Gen-IV SFR with a capacity of 150 MWe is under design, and this prototype reactor is scheduled to operate from 2028. For a commercial SFR system application, it is necessary to develop an advanced structural material having both high creep strength and irradiation resistance at high temperatures (Jeong, 2014). Oxide dispersion strengthened (ODS)steel is one of the most promising structural materials because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperatures under a neutron irradiation environment for a prolonged operating period(Kim, 2016). As the first step, several batches of ODS steel were designed and the candidate samples with a 2 kg scale each were fabricated by mechanical alloying, hot isostatic pressing and hot rolling processes. The mechanical properties of these samples were evaluated. Up to now, two candidate materials with chemical compositions of (in wt%) Fe-10Cr-1Mo-0.5Mn-0.1V-0.25Ti-0.35Y2O3 was selected as representative materials, and these materials were named as the advanced radiation resistant ODS steel (ARROSTM).The next step was to optimize the fabrication process of the ARROS compositions for in-core structural components such as the fuel cladding tubes of a SFR. An optimized fabrication process of fuel cladding tube with a composition of ARROS has been established through various process conditions in mechanical alloying, hot consolidation, hot/cold working and heat treatment processes. Joining technologies of the ODS steel tubes is being developed using solid-state welding such as magnetic pulse welding, friction stir welding and diffusion boding. It is expected that the development of ARROS will contribute to the realization of a commercial SFR with high economics and sufficient safety in the future. In this paper, the study of fabrication process of ARROS structural components is introduced."

Jan 1, 2017

By L Nienaber

Mines, after becoming operational, often retain the same support and reinforcement designs developed in the feasibility study. These designs are conceived from limited drilling data and regional experience, thus having an empirical flavour. Empirical designs are perceived to be conservative, catering for a variety of failure mechanisms, which are not always present in mine development drives.This begs the question: If you were to invest in the necessary resources to obtain sufficient data and complete the required analyses for the different development drives in the mine, to engineer a support and reinforcement scheme with the capacity to match the demand of the rock mass, what is the difference in cost when comparing an empirical design to an engineered design?To answer this question, mine tunnels with different geometries and orientations, where detailed structural data was available, were selected for a comparative design exercise. Material cost, development cost, cycle time and professional fees for engineered and empirical designs were estimated. The outcome is summarised in the following paper that discusses the process followed and the results of the design comparison.

Mar 8, 2011

By Marvin S. Seppanen

Computer programers are often required to make modifications to unfamiliar Fortran routines. This Bureau of Mines report describes a computer program designed to aid the programer in such a situation by reorganizing: Fortran routines. This reorganization includes a sequential renumbering of the routine's statement numbers, a sequential renumbering, and relocation of format statements, an alphanumeric reordering of dimensioned and typed variables, a uniform pattern of text spacing, and a sequential numbering of the records in the final Fortran routine. The computer program has been extensively tested by the author and has proved to be a valuable tool for reorganizing Fortran routines developed under contract and later utilized by the Bureau, and for preparing routines for publication.

Jan 1, 1975

By Z. Zhang, J. Niu, H. Wang, Y. Xu, J. Shi

Tribo-electrostatic separation is a promising method for effectively utiliing low-grade magnesite resources by removing quartz and improving the grade of magnesite. To determine the chargeto- mass ratios of pure magnesite and quartz, a triboelectric measurement system was employed, and a laboratory tribo-electrostatic separation system was used to separate low-grade magnesite. The results showed that the maximum difference in charge-to-mass ratio between pure magnesite and quartz particles was observed after friction with polyvinyl chloride. The grade and recovery of magnesite increased with temperature and initially increased with increasing voltage, feed rate, and air flowrate before gradually decreasing. The optimal conditions resulted in a concentrate with 46.91% MgO content and 77.36% recovery, while the quartz content decreased from 7.02% to 1.95%. These experimental results demonstrate the effectiveness and potential of tribo-electrostatic separation in removing quartz and upgrading magnesite.

Apr 14, 2024

By B. Mbuya, A. F. Mulaba-Bafubianda, J. M. Mvita

The paper explains the main effects of input leaching parameters, such as addition of a reducing agent, acidity, agitation, temperature, and leaching system potential, in relation to observed and predicted yields of sought-after cobalt. An artificial neural network coupled with graphical probability networks was developed wherein the abovementioned input parameters were used to predict the percentage of dissolved cobalt. Furthermore, similarities and differences between the Bayesian and neural network approaches in terms of their key outcomes are compared with respect to study of the dissolution of cobalt in sulfuric acid. Key results indicate that there is a need to use neural network results to predict conditions for dissolution of cobalt, while using Bayesian network to explain inferences about conditions of the input parameters, thereby achieving realistic predictions.

Jan 1, 2023

By D. A. Larson

This is the second in a series of Bureau of Mines reports which de-scribe experiments designed to devise an efficient, economic mechanical fragmentation technique for hard rock. The previous study described the development of the ripper cutting technique to successfully cut hard rock with 3-to 6-in-wide drag cutters. This study was conducted to test the ripper cutting technique at full scale using 9-in-wide drag cutters. The experiments were conducted with a special test device that cut shallow, 6-by 6-ft openings in 9,200-lbf/in2 compressive-strength concrete blocks. The tests showed that ripper cutting can excavate large-scale openings of the type required by the mining industry at a production rate that outperforms the conventional drill-blast technique. Moreover, the system can produce openings of various sizes and shapes, is simple to oper-ate and maintain, and produces very little dust or noise during operation. The system appears to meet all of the criteria for a successful hard-rock mining machine.

Jan 1, 1987

By Luca Pingue, Regine Jagow-Klaff, Franco Muratore, Carlandrea Albonico, Damiano Frontini, Rudolf Wernecké

This paper describes an artificial ground freezing (AGF) application carried out to ensure both watertightness and structural support for the safe excavation of four cross passages of the Forrestfield Airport Link (FAL) project in Perth. The line will deliver 8.5 km extension of the existing urban rail network connecting the growing eastern suburbs of Perth with the existing suburban rail network. The proposed soil improvement technique is adopted as a smart alternative to jet grouting from the surface since the use of heavy equipment with long vertical mast was not allowed due to the line underpassing an airport in operation. In this paper, details of the challenges and lessons learned during both design and construction phases are given. Furthermore, it is described the geometry and the installation of freeze pipes in presence of a massive steel frame, ventilation system and slurry pipes of the tunnel boring machine (TBM) in operation. It is also illustrated the web monitoring system to allow key personnel to follow in real time the development of soil temperatures, tunnel convergences and ground surface deformations as well as changes in the interaction between international parties involved due to the COVID-19 pandemic.

May 1, 2022

Provide an inexpensive, simple means of supporting highly yielding ground In underground mines. Approach The Bureau of Mines developed a high capacity support post made from standard steel pipe which, when using a 60-inch post configuration, has a 45-ton capacity and a yield length of 24 inches. How It Works The post mechanism is a three-piece unit consisting of a top and bottom leg (made from standard steel pipe) and a separate foot bracket. During installation in the mine, the bottom leg is placed on a relatively flat surface on the mine floor and the top leg is placed over it until its flared end contacts an expansion ring attached to the bottom leg. As the roof and floor converge, the flared end of the top leg is forced into the expansion ring, causing the walls of the top leg to be deformed radially and along the axis. The mechanism will yield until the unit bottoms out after about 24 inches of yield.

Jan 1, 1987

By Raúl Hidalgo

El presente trabajo describe el plan estratégico de la mina San Vicente, ubicado en la provincia de Chanchamayo, departamento de Junín. Entre los objetivos de la mina está el aumento de la productividad a través de la reducción de costos de operación y realizar labores de pre-minado de 20 m/ día en los avances de operaciones. En este sentido, si bien la función del mecanizado es importante para el incremento de la productividad, es necesario controlar y administrar los recursos del nuevo yacimiento. Por ello, para implementar la nueva tecnología del minado es necesario el estudio de mecánicas de rocas y asi determinar la característica de la masa rocosa y la factiblidad económica para excavados mediante el sistema de minado contínuo.

Aug 26, 1988

By Donald C. Wotring, Douglas A. Gabriel, Michael G. Vitale

"The Northeast Ohio Regional Sewer District (NEORSD) recently completed the 24-foot diameter Euclid Creek Tunnel using a steel-fiber reinforced concrete segmental lining. During construction HMM, the McNally/Kiewit JV, CSI/Hanson JV, and the NEORSD performed a test program to evaluate replacement of steel fiber with synthetic fiber. A section of synthetic-fiber-reinforced cast-in-situ lining was also placed as part of the permanent works for the starter and tail tunnels. Laboratory and field testing were performed on two complete segmental rings reinforced solely with synthetic fibers. This paper summarizes the testing program, construction, and results of the synthetic-fiber-reinforced CIP lining and concrete segments. INTRODUCTION The principal feature of the Euclid Creek Tunnel (ECT) project is a CSO storage tunnel that is one component of the Northeast Ohio Regional Sewer District’s (NEORSD) Easterly CSO storage and conveyance system. The tunnel, shafts, and appurtenant facilities will be used for the collection and storage of CSOs from the northeastern part of Cleveland, Ohio and subsequent conveyance to the NEORSD’s Easterly Wastewater Treatment Plant for treatment. The ECT project includes five drop shafts that extend as deep as 220 feet below the ground surface. The ECT alignment and shaft locations are shown in Figure 1. Traditionally in northeast Ohio, tunnel excavations were supported with a two-pass system using steel ribs and timber lagging, followed by cast-in-place concrete. Control of rock overbreak proved difficult with large-diameter two-pass operation, and invert degradation led to train derailments. To mitigate these risks, the ECT was supported using one-pass, precast, bolted, gasketed concrete segments reinforced with steel fiber alone. Tunneling operations were very successful and experienced no significant delays or claims. As a result of the positive ECT experience with steel fiber-reinforced segments, Hatch Mott MacDonald, LLC (HMM), McNally/Kiewit (MK) joint venture, CSI/Hanson (CSI/H) joint venture, and the NEORSD performed a test program to evaluate replacement of steel fibers with synthetic fibers in segmental rings. This paper presents the laboratory and field testing program, construction, and results of the synthetic-fiber-reinforced cast-in-place (CIP) lining and concrete segments."

Jan 1, 2016

By S. R. Rannels, D. E. Rannels

"I. IntroductionThe alveolar surface of the lung is covered by two populations of pneumocytes, type I and type II epithelium. The type I cell, which accounts for most of the alveolar surface area and provides a highly specialized barrier for gas exchange (Rannels et al., 1991), is poorly understood. Although approaches to type I cell purification have been discussed, they have not been applied widely because of the lack of phenotypic markers to monitor isolation procedures (Dobbs et al., 1988; Danto et al., 1992). In contrast, the type II cell has been studied extensively, largely because of the development of reliable procedures for its isolation and primary culture. Investigations based on the use of purified populations of cultured type II cells have provided convincing evidence to support a role for the pneumocytes both in the maintenance of normal lung function and in the response of the lung to injury (for review, see Rannels and Rannels, 1989).While type II cells can be isolated by a variety of approaches, the protocols used most commonly are modifications of the gradient method of Dobbs and Mason (1979) or of the panning method of Dobbs et al. (1986). Purification of the cells based on density gradient centrifugation is reliable and consistent, with yields of 30 to 40 X 106 type II cells per rat of 230 g body weight. Isolation procedures applied to a minimum of three to four rats provide the best results, as lower cell yields are common with the use of fewer animals. The protocol below is designed to obtain a maximal cell yield from the lungs of six rats.II. Materials and InstrumentationMaterialsCalbiochem: DNase I (Cat. No. 260912); Corning: culture flask, 75 cm2 #25115; Costar: culture plate, 24-well #3424; disposable serological pipette #4101; Elastin Products Inc: elastase #E-134; Falcon: cellulose nitrate membrane filter, 0.22 µm, #7105; conical tube, 50 ml, #2070; culture dish, 100 mm, #3003; culture plate, sixwell, #3046; Fisher: BaS04 , #B68-500; NaCl, #5271-3; NaHC03 , #5233-50; Fort Dodge Laboratories: pentobarbital, #1206-lE; Gibco: Dulbecco's minimal essential medium (DMEM), #430-1600EC; Hanks' balanced salt solution (HBSS), #310- 4185AG; Joklik's modified Eagle's medium (JMEM), #410-2300EC; HyClone Laboratories Inc: fetal calf serum (FCS ), # A-1115-L; I CN Biochemicals (Flow Labora tories): amphotericin B, #16-723-48; newborn calf serum (NCS), #29-121-54; try pan blue, # 19 5 5 32; Na/gene: Erlenmeyer flask, # 100-4116C; Pharmacia: Percoll, #17-0891-01; density marker beads, #17-0549-01; Sigma: gentam1cm sulfate, #G3632; penicillin/streptomycin, #P3539; trypsin inhibitor, #T9128; Tetko: HC- 160 nylon mesh, #3-160-53."

Dec 1, 1995

By Jerold L. Johnson

Remediation of small-arms firing ranges is being investigated by the Naval Civil Engineering Laboratory and the U.S. Bureau of Mines. Scheduled closures of military installations, as well as the management of active ranges, require the development of methodologies for heavy metals removal to prevent their entering the surrounding environment. The impact berms contain high concentrations of metals, and the soil and vegetation surrounding the berms were found to have slightly elevated levels. The heavy metals characterized are in the form of whole bullets, a wide size distribution of free fragments, smeared lead on the surface of the soil grains, and very finely attached particles. Gravity beneficiation can remove liberated metal contamination effectively. Weak acetic acid leaching shows promise in lowering the final metal contamination to allow the ,soil to pass the Environmental Protection Agency's (EPA) Toxicity Characteristic Leaching Procedure (TCLP) criteria.

Jan 1, 1993

By C. E. Corson

THE experiments of which the results and significance are set forth in this paper do not by any means cover the whole subject of the heat-treatment of the material referred to, yet they constitute a contribution to that general subject, rather than to the special department of annealing. The material here considered is acid open-hearth steel, containing from 0.50 to 0.80 per cent of carbon, with a nearly uniform percentage of other elements. This class of steel is rapidly increasing in commercial importance. It is even rumored that the rail-specifications of some railroads will hereafter require open-hearth steel. Yet this particular grade seems to have received less study and description from the standpoint of the metallographist than many others. The investigation here described was directed to the following points:-Steel containing about 0.50 per cent, of carbon : 1. The structure as related to the temperature, at the same rate of cooling; 3. The structure and physical properties as related to temperature at different rates of cooling; 3. The structure and physical properties as related to different finishing-temperatures and different rates of cooling; 4. The bearing of these observations upon the statement of Prof. Albert Sauveur.1

Sep 1, 1906

By WM. G. Heeley

This paper will describe the experience gained and explain the deductions made from the phenomenon of the great squeeze which occurred at Brule Mines. The first indication of the commencement of the squeeze was the breaking of posts on the high-side rib of the slope. At first we thought this was due to a lateral pressure only, and we renewed the broken posts with new ones, the result being that the new posts also were soon broken. A noticeable bending and breaking of the collars occurred, with a corresponding reduction in the height of the haulage slope. These symptoms were also evident on the counter above the slope, indicating that the trouble was of an exceptional nature. In the meantime, we had concentrated a large force of repair men, renewing broken timbers and brushing the roof and floor, but in spite of all our efforts we could not overtake the damage being done. Our next problem was to find the cause of this trouble. We were in a new basin of coal (No. 2) which had only been opened a few months, as we had worked the previous four years in another basin (No. 3) where no such trouble as this had ever been encountered. Naturally our first thought concerned the adequacy of the size of the pillars. We had worked in the No. 3 south basin for the previous four years. without any such experience, with 60-feet pillars between slope and counters; whereas we had established 100-foot pillars in the No. 2 south basin between the slopes and counters with an 80-foot pillar between counter and first line of cross-cuts, and 100-foot pillars between the breasts.

Jan 1, 1924

By A. F. Cohen

When location guidelines are followed in choosing sites for fixed point velocity transducers for use in underground coal mine monitoring, mine air turbulence intensities <11% are generally expected at those sites. The objective of this Bureau of Mines investigation to determine the effect of turbulence intensities <11% on vortex shedding sensors and transducers. Measurements were made at velocity levels of interest for underground coal mine monitoring use (?200, ?500, ?1,000, ?1,500 ft/min). The effect of grid-produced turbulence intensities (2% to ?14%) on the output of vortex-shedding air-velocity transducers was less than ±10%.

Jan 1, 1985

By AIME AIME

M ODERN metallurgy properly belongs to this century. The great advance made in this science is directly attributable to the discovery of the Roentgen rays. Application of the results of this discovery, together with the more recent corroborating studies in electronic diffraction have definitely and for all time established this science. Metallurgists today speak with familiarity of the atoms of the different metals in terms of their orientation, atomic volumes, lattice structures, dimensional lattice constants distance of nearest approach, and the like. One matter of profound interest, which is quite staggering to the imagination of the human mind, is the enormity of the number of atoms even in a small particle of metal. As an illustration, let us compute the number of atoms in the volume of one cubic centimeter in a single grain of absolutely pure copper. Eighteen and a fraction cubic centimeters equal the volume of one cubic inch.

Jan 1, 1940

By Joseph Cervik

Common methods of controlling gob gas in U.S. nines are by means of ventilation of gob areas and gas drainage through surf ace boreholes. Costs of drilling surface gob holes increase as deeper coalbeds are mined. Where gob holes cannot be drilled because of topography, ventilation is the only means of control. Even then, sufficient air may not be available to dilute methane in the bleeder entries to acceptable levels. Thus, new methods of gob gas control need to be developed that are independent of surface topography, and of the mine ventilation system, and less costly than present systems. Except for slight variations in procedures and equipment, Great Britain, West Germany, France, Belguim, Poland, and Czechoslovakia use a common methane control method that is different from the system generally used in the United States, This Bureau of Mines paper reviews European mining methods, mining conditions, and methane control technology and discusses their applicability to U.S. mines.

Jan 1, 1979

By Sirish L. Shah

It is now common to have archival history of thousands of sensors sampled every second over long time. Yet we frequently have process engineers complain:??.We are drowning in data but starving for information??. How can these rich data sets be put to use? This paper addresses the issue of information and knowledge extraction from data with emphasis on process and performance monitoring including fault detection and isolation. Most of the major plant, factory, process, equipment and tool disruptions are avoidable, and yet preventable fault detection and diagnosis strategies are not the norm in most industries. It is not uncommon to see simple and preventable faults disrupt the operation of an entire integrated manufacturing facility. For example, faults such as malfunctioning sensors or actuators, inoperative alarm systems, poor controller tuning or configuration can render the most sophisticated control systems useless. Such disruptions can cost in the excess of $1 million per day and on the average they rob the plant of 7% of its annual capacity. Over the last decade the fields of multivariate statistics and data visualization and analysis methods have merged to develop powerful sensing and condition-based monitoring systems for predictive fault detection and diagnosis.These methods rely on the notion of sensor fusion whereby data from many sensors or units are combined with process information, such as physical connectivity of process units, to give a holistic picture of health of an integrated plant. Such methods are at a stage where these strategies are being implemented for off-line and on-line deployment. This article attempts to outline the field of sensor fusion - the application of signal processing methods, in the temporal as well as spectral domains, on a multitude and NOT singular sensor signals to detect incipient process abnormality before a catastrophic breakdown is likely to occur Keywords: Process analytics, process and performance monitoring, multivariate statistical analysis, sensor-fusion

Sep 1, 2012

By David S. Yantek

A-weighted sound levels around vibrating screens in coal preparation plants often exceed 90 dB(A). The National Institute for Occupational Safety and Health (NIOSH) is actively developing noise controls to reduce noise generated by horizontal vibrating screens. A 121-microphone, 3.5-meter-diameter array was used to perform beamforming to determine locations of significant noise radiation on the screen. Below about 1 kHz, the screen body was found to be the most significant noise source. The beamforming contour maps showed several key locations on the sides of the screen and the feedbox are the most significant contributors. Operating deflection shape (ODS) analysis was used to examine the screen behavior under actual operating conditions. This information is helpful in determining how to modify the screen body to reduce the noise radiated by the screen below 1 kHz. The analysis showed modal vibration patterns on the sides and feed box were the main contributors to noise. The results show several areas on the screen sides and feedbox that can be modified to reduce noise.

Jan 1, 2009

By Diego Benites Negrón

El presente texto describe los resultados de la caracterización mineralógica de 28 muestras con contenido en sulfosales de plomo y cobre de origen hidrotermal provenientes de la sierra central del Perú. Por ello, se busca caracterizar la mineralogía de la zona con énfasis en las sulfosales y el aporte de la plata que esta pueda contener. Asimiso, se realizaron análisis mineralógicos por difracción de rayos X a fin de conocer las especies minerales no metálicas.

Feb 1, 2017