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By J. van der Merwe, C. Phetolo, V. Matjeke

The mechanical properties and microstructure of AlSi10Mg alloy samples that were printed by selective laser melting (SLM) were studied to determine the effect of processing parameters and building orientation. After printing, the alloy was stress relieved at 250°C for 2 hours. The microstructures were analysed by optical microscopy and scanning electron microscopy (SEM) to determine the alloy phases and distribution. Phase transformation characteristics of the material were evaluated using differential scanning calorimetry (DSC). Mechanical properties were determined by subjecting the XY- and Z-built samples to tensile and nano-indentation testing. The samples from the tensile tests were then used to perform fractographic analysis by SEM. The microstructural properties in each orientation revealed a non-homogeneous microstructure which was characterized by a semi-elliptical tract and fine silicon precipitates, which were found to be softer along the fusion zone. The DSC thermograms revealed that the material underwent two phase transformations during the first heating cycle. The mechanical properties revealed a higher UTS, higher yield strength, and a lower percentage elongation in the Z orientation than in the XY orientation. Fractographic analysis showed that crack initiation in both orientations started from the surface in a brittle manner due to surface flows, and then propagated via microvoid coalescence.

Jul 1, 2021

It is a common misconception that the grant of mining tenure, whether it be an Exploration Permit, Mineral Development Licence or Mining Lease, will entitle the holder to access all land within it in order to explore or mine. The ability for miners to access their tenure in order to undertake activities is critical to the industry. While significant time and energy is quite rightly dedicated to resolving native title and cultural heritage issues before the commencement of mining operations, the same cannot always be said for addressing potential impediments that arise as a result of the overlap between mining and other tenures. Miners should be aware of the overlaps that occur with other tenure and the impact of these overlaps on the minerÆs ability to explore or produce from the area. The existence of an overlap with petroleum tenure, nature refuges, national parks, wild river areas or reserves such as aboriginal land leases are all likely to have an impact on the minerÆs ability to access the area and conduct activities. In some instances, such as an overlap with petroleum tenure, Queensland legislation encourages the miner to reach agreement with the holders of the overlapping tenure. However, in other instances, such as an overlap with a national park, mining tenure is unlikely to be granted at all. This paper summarises the impacts and impediments that arise as a result of overlaps of tenure that are likely to affect mining operations. It also provides examples of how these impediments can, if possible, be overcome under Queensland legislation.

Jan 1, 2007

1. Domestic Production and Use: Twelve companies operated 31 primary aluminum reduction plants, three firms accounting for 66% of production. Washington, Oregon, and Montana accounted for 32% of the total production; Gulf Coast States, 25%; Northern States, 29%; and other Southern States, 14%. Output of primary metal in 1973 was valued at $2.2 billion. About 80% of the secondary recovery was from new aluminum base scrap and 20% was from old scrap. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1972, building accounted for 28%; transportation 19%; electrical, 13%; packaging, 16%; and consumer durab1es, 10%.

Jan 1, 1974

By Julia Pflieger, Manfred Russ, Johannes Gediga

This paper shall show an economic feasible approach to implement Greenhouse Gas (GHG) reduction measures into the mining and metallurgy industry. The goal to improve energy consumption is directly linked to the reduction of GHG emissions and therefore directly in correlation with the economic viability. A baseline scenario of the considered reference system and of the respective reference year has to be defined, mapped and analysed. In a second step an analysis of the same operation using available and prospected Best Available Technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified reduction potentials are reported and the GHG emission reductions are put into relation to the investment cost of the new process technologies / process adaption to be implemented. This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap implementation into the company's business operations. The GHG reduction roadmap is developed using ratios between GHG reduction and investment / operating cost to get an indication for a sequence for implementing carbon emission reductions measures.

Jan 1, 2010

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson

"The United States (U.S.) Department of Homeland Security (DHS) Directorate of Science and Technology (S&T), utilizes a probabilistic risk assessment (PRA) approach to explore the risks (anduncertainty) from chemical, biological, radiological and nuclear (CBRN) threat agents to the Homeland.This end-to-end risk methodology considers a broad range of hazards incorporating emergingtechnologies, available countermeasures and input from the Intelligence and Law Enforcementcommunities (IC/LE) to evaluate the acute risk to human health due to an attack on the U.S. homeland. The PRA generated output provides a mechanism to examine risk mitigation strategies, critical vulnerabilities, critical data and knowledge gaps and relative risk rankings of materials, targets, classes of compounds and scenarios."

Jan 1, 2017

By N. Romani, R. Provost

"Commissioning of a circulating dry scrubber plant was recently completed at an existing facility, in order to treat the sulphur dioxide off-gas emitted from rotary kilns. Proper planning of the different commissioning stages and staffing an integrated team are the most important factors required for a successful plant start-up. A strong operational readiness plan must be in place as early as the start of construction in order to ensure a smooth transition from commissioning to operations. Plant performance can meet or exceed performance criteria within the required timeframe if the proper group dynamic and good communication is established between construction, commissioning and operations teams.INTRODUCTIONCommissioning of a circulating dry scrubber (CDS) plant was recently completed at an existing facility in Quebec, Canada. The CDS plant treats the sulphur dioxide off-gas emitted from rotary kilns in order to meet increasingly stringent environmental requirements. This installation enables the existing facility to reduce their sulphur emissions by over 90%.The CDS ProcessA general overview of the CDS process is presented in Figure 1 below. The combined, de-dusted off-gas from multiple kilns is sent to the CDS, which acts as an entrained fluid bed, where the gas is contacted with a water mist, re-circulated solids and hydrated lime. The SO2 from the gas stream and the available calcium hydroxide (Ca(OH)2) from the hydrated lime dissolve in the water and react to ultimately form calcium sulphites and gypsum. The solid residue (referred to as CDS residue), is the primary byproductof the process.Fresh hydrated lime and CDS residue is captured by the dust collection system and is re-circulated to the CDS via a fluidised transport system. Clean off-gas passes through the dust-collection system and is then sent to the atmosphere by a single exhaust fan.The CDS residue purged from the system is combined with the dust collected from the kiln offgas system and this mixture is wetted in the already exiting agglomeration system, to minimize dust generation during handling, and then sent to disposal."

Jan 1, 2016

By N. A. Warner

Virtually zero gas emission smelting is promoted as a means for securing environmental advantages and the general public’s acceptance. Concerns about climate change will increasingly make it more difficult for new primary metals projects to come to fruition unless greenhouse gas emissions are decreased. Assuming a sustainable market for sulphuric acid is not locally available, the next best option is high temperature reaction of strong SO2 with limestone or dolomite. This is followed by CO2 liquefaction and disposal either underground or in the deep ocean. The Voisey’s Bay nickel project is cited as an example where appropriate location of a new smelter close to large dolomite or limestone deposits would lead to a virtually zero gas emission operation. Most of the electrical energy required for producing technically pure oxygen and for liquefying CO2 and transporting it to disposal can be derived from smelting a bulk sulphide concentrate and then reacting SO2 at high temperature. Provided the smelter gases are properly cleaned before sulphur fixation, the sulphated stone should be uncontaminated and environmentally benign and possibly of use in the building and construction industry.

Jan 1, 1999

By W. L. Dare

This publication is one of a series prepared by the Federal Bureau of Mines on methods and costs of producing uranium ore on the Colorado Plateau. The information it contains was gathered in 1955-58 and applies to eight small operations. (See fig. 1.) Mining costs have increased since the data were I collected, but the information should be helpful in estimating future costs I at similar deposits. The Bureau of Mines had early experience in the production of carnotite-type ores on the Colorado Plateau.3 4/ Under a cooperative agreement with the National Radium Institute in 1914-16, the Bureau mined and concentrated carnotite ore for recovery of radium, uranium, and vanadium. The ore was taken from claims in or near Long Park Montrose County, Colo., about 3 mi. south of La Salle Mining Co.'s La Salle mine, which is one of the mines described in this report. The Bureau leased the claims from Crucible Steel Mining & Milling Co., a subsidiary of Crucible Steel Co. of America, and from 1914 to 1916 produced 990 tons of high-grade ore, containing 2.6 pct. U308, and about 2,000 tons of mill-grade ore, containing 0.85 pct. U308. The high-grade ore was shipped directly to a radium-recovery plant built in Denver in 1914 under the cooperative agreement. There, commercial methods of extracting uranium, vanadium, and radium from carnotite ores were developed by Bureau personnel. The lower grade ore was concentrated at a small mill in Long Park before being shipped to Denver. The final recovery was 69,000 lb. of U308 and 8.8 g. of radium. The direct mining cost of producing the high-grade ore, including the labor to hand sort and sack it, was $35.96 per ton. Freighting the ore 58 miles to Placerville, Colo., the nearest rail point on the Rio Grande Southern Railway, cost $25.28 per ton, which included $4.55 per ton for ore bags and twine. Four-or six-horse teams pulled two wagons in tandem and made the

Jan 1, 1961

By J. Dubbert, T. H. Jones

"This paper describes a rib-control methodology that uses standing support to provide most of the lateral resistance to the rib. The method is analyzed, and its boundary conditions for rib control are described. In this method, an animal-fencing mesh product covers 80 percent of the rib surface and is sparsely bolted to the rib. Can supports or other similar stiff supports are installed primarily as roof support for the entry. As the rib spalls and dilates, the mesh catches the material and expands, pressing against the standing support. Mining proceeds, and vertical roof loads increase the normal force on the Can supports, causing friction at the top and bottom of the support to go up, thereby improving lateral resistance to rib swelling.At one mine in the western United States, this method has proved excellent at preventing the buildup of rib spall. It substantially reduces the number of bolts used for screen installation, improves installation efficiency, reduces manual labor and provides more rib coverage than many screening methods. Because standing support is typically part of the roof-control plan in longwall tailgates, no additional standing-support costs are incurred. IntroductionRib safety in underground coal mines is an oft-studied topic because ribs are high-hazard areas. An overview of early rib safety research can be found in Jones and Mohammed (2014). There is a significant difference between rib support and rib control. Support improves safety through the installation of strengthening elements, such as bolts and dowels, designed to reduce rib spalling. Although spall reduction is preferred, controlling how the rib fails is enough to ensure safety in some situations. Rib control uses external elements to provide confinement, thereby holding sloughed material in place, or to prevent falling rib material from striking mine personnel. This paper presents a study of a control method used on the pillar side of a longwall coal mine tailgate in the western United States."

Jan 1, 2015

By Glenn C. Reed

This report is one of a series describing investigations within the Missouri River Basin in Montana made by mining engineers of the Bureau of Mines Minerals Division, Region II. The primary purpose of these investigations is to provide information to agencies of the Department of the Interior and and others concerned with the planning of Federal power developments in the basin. The report contains such factual data as have been authorized for public distribution. The field investigations in Broadwater County were made during the late fall of 1948 and the summer of 1949. Virtually all known metallic mineral deposits and some nonmetallic mineral deposits within the county were investigated. However, some long inactive mines and prospects on which little or no information is of record may have been omitted inadvertently. Many of the mines and prospects have been inactive for extended periods. Most of the underground workings now are inaccessible. Because of such conditions, impressions gained by the inspection of surface features have been supplemented necessarily, where possible, by information obtained from Federal and State publications.

Jan 1, 1951

By José Hugo de Carvalho Souza

Buscando melhorar a detecção das causas de falhas em equipamentos pela equipe no setor de trefilados e ampliados, o tempo de reparo de manutenção, diagnóstico de desempenho dos processos e melhoria na segurança operacional, foi criado um sistema de informação integrado de engenharia de manutenção e processos, com plataforma de carta de controle online e off-line integrada, monitorando aproximadamente quatro mil e trezentas variáveis de processos analógicas e digitais, adicionadas câmeras IP nos processos e desenvolvido um sistema de rastreabilidade de volumes produzidos que garante o correto apontamento de produção da área, minimizando dessa forma as divergências de inventário. A criação da rede integrada, permite unificar as comunicações de automação, possibilitando monitoramento e modificações das lógicas nos PLCs na central da automação, agilizando os diagnósticos e padronizando backups. A partir das implementações e projetos, foi possível aumentar no período de 12 meses em 5,5% a produtividade e otimizar em 2,9% o resultado de interrupção de manutenção dos equipamentos.

Aug 16, 2017

By Janet Torma-Krajewski

Job tasks that involve exposure to work-related musculoskeletal disorder (WMSD) risk factors may impact both the risk of injury and production downtime. Common WMSD risks factors associated with mining tasks include forceful exertions, awkward postures, repetitive motion, jolting and jarring, forceful gripping, contact stress, and whole body and segmental vibration. Mining environments that expose workers to temperature/humidity extremes, windy conditions, and slippery and uneven walking surfaces also contribute to injury risk. National Institute for Occupational Safety and Health (NIOSH) researchers worked with powder crew members from the Bridger Coal Company to identify and rank routine work tasks based on perceived exposure to WMSD risk factors. This article presents the process followed to identify tasks that workers believed involved the greatest exposure to risk factors and discusses risk reduction strategies. Specifically, the proposed prill truck design changes addressed cab ingress/egress, loading blast holes, and access to the upper deck of the prill truck.

Jan 1, 2009

By Robert S. Sanford

Intensive investigations of domestic manganese deposits were conducted by the Bureau of Mines and the Geological Survey during the earlier part of the war minerals investigations when there was doubt that the quantity of manganese needed to produce the greatly increased tonnage of steel demanded for war supplies could' to obtained from its customary sources. Domestic deposits of ores that contain sufficient manganese for direct production of ferromanganese essential in steel Manufacture are generally small, and the bulk of the supply is imported. One of the few large deposits of low-grade manganese ore known in the United States is in the Artillery Peale district in southern Mohave County, Ariz. Manganiforous sediments underlie a very large area. Several large groups of claims, covering the most of the manganese-bearing ground, wore assembled in 1929 and 1930. The greater part of this area was leased by the M. A. Hanna Co. in 1937. Investigations by engineers and geologists for this company revealed that the average content of manganese is very low; but that the Maggio Canyon area, about 180 acres, contains higher-grade material. The company put down 28 vertical diamond-drill holds to explore this ground, under the direction of B. N. Wobbor, geologist.

Jan 1, 1948

By I. Lazaro Roche, J. Brunner, J. Busto, X. Martin, J. B. Decitre, S. Gaffet, F. Hivert

"Muon tomography allows investigating the subsurface. Muons being penetrative, the attenuation of the muon flux depends on the quantity of matter the particles travel through, hence on the rock density and thickness. For the Temporal Tomography of rock Density using Muon Measurements (T2DM2) project, the muon flux measurements are performed in LSBB URL (http://www.lsbb.eu) in order to study the hydrogeological processes in the unsaturated area of Fontaine-de-Vaucluse karst aquifer. The suitability of the muography for this study is here numerically demonstrated. In parallel to these simulations, muon flux measurements are carried out in the LSBB galleries by means of a set of four scintillator tanks and Micromegas detectors are developed. These detectors, here described, are adapted for underground and confined spaces as well as other environments. Their performances are particularly interesting and should contribute to the expansion of muon tomography in new application fields. INTRODUCTIONMuon tomography or muography is a method to image large volumes by measuring the absorption of cosmic ray muons. It uses, in a passive way, a natural radiation source: the muons which are charged particles produced in the atmosphere. Primary cosmic rays interact with atmospheric nuclei and produce a huge number of secondary particles, including muons. Due to their important mass compared to electrons, they are highly penetrating, reaching several hundreds of meters below the surface. Their attenuation depends on the quantity of matter they cross. That's why they are used to investigate the subsurface, muon absorption measurement allowing to estimate the in-situ density of the rock.Georges (Georges, 1955) proposed in 1955 to use the muons in order to study the density variations caused by the overburden over an Australian tunnel. In 1970, Alvarez (Alvarez, 1970) imaged the internal structure of Chephren Pyramid thanks to this method. The muon tomography has been particularly developed for volcanology (Nagamine, 1995; Tanaka, 2007; Lesparre, 2010; Carloganu, 2013) over the last twenty years. Since the beginning of the 2010's, a growing amount of projects that proposed to use the muons in various fields get underway: the CO2 storage (Kudryavtsev, 2012), the exploration of Mars (Kedar, 2013), etc."

Jan 1, 2015

By H. J. Oterdoom

SMS Group (SMSG) has always been concerned about safety aspects of electric smelter plants for the ferro-alloy and non-ferrous industry. The awareness for safety increased significantly over the past decades and also SMSG contributed with its design features to a safer operation. Today, safety aspects are not only part of the smelter design but also of the overall plant layout. Explosions in electric smelters are rare, but have a huge impact on peoples’ lives, on equipment and on production. For this reason, SMSG wanted to have a better overview of explosions within the smelting industry in order to see if useful statistics could be extracted. Generally, there is a lack of statistics regarding explosions in the electric smelting industry, and not enough information is collected or published. A significant portion of the explosions seems to be water related. Many companies, both operating and engineering, are trying to handle the risks of water, and apply methods to detect water leakages. Installing such a system is a management decision and management has then to make sure the system is properly implemented. The disadvantages and limitations of these systems should be carefully considered and communicated to operators and authorities.

Jan 1, 2015

By Alfonso Rizo-Patrón

El presente trabajo describe la importancia de la explotación de los fosfatos de Sechura en la cuenca del Pacífico. Para ello, se evalúa el potencial de recursos naturales aprovechables en una infraestructura concentrada del área de Bavoyar y su implicancia en el aprovechamiento del potencial para el año 2000. Asimismo, es importante la planificación de un programa y una coordinación técnica adecuada de las realidades físicas, geográficas y geológicas de la cuenca señalada, así como la responsabilidad que ello implica.

Nov 20, 1972

By A Huebner, A Noack

Companies all over the world are very sensitive concerning their IT and network security. In most network connected technical installations and machines however, network security is not taken into account to a significant extent: insecure protocols are run, unencrypted information is exchanged freely and even broadcasted wirelessly and networked machines are accessible via insecure file transfer protocol (FTP).What happens in case of malfunctions of such technical installations? Who is responsible? Who can be held liable in case of accidents? The first computer worm for automation systems (æSTUXNETÆ) (Symantec, 2010) was discovered during 2010.The paper is intended to create sensitivity among decision makers for potential security and resulting safety leaks and points out the current status quo in technical network security. It outlines best practices for secure networking and procedures for remote access and remote software updates on stationary equipment and mobile mining machinery. It describes how to ensure authentic and genuine configurations and software targets and how to ensure secure communication for autonomous and remote controlled equipment. For such equipment in particular, the following statement should apply: æThere is no safety without network securityÆ.

Sep 26, 2011

By E. L. Martheleur

The use of electricity in coal mines dates almost from the time when it was realized chat it could be used to produce mechanical power. The first motor put in service underground was installed to drive a small pump nearly 40 years ago, and since then the use of electricity in mines has reached an extent undreamed of at that time. We now find its universal adoption in all the mining countries of the world. Great progress has been made in the development of mining electrical apparatus in the last decade, and excellent and adequate material is now available for the use of electricity underground. Although mining accidents, due to the use of electricity, are not frequent, the miner is justified in demanding chat all electrical apparatus for installation below ground be constructed with a greater degree of safety than that used on the surface. That this view is shared by the authorities of the different mining countries is evidenced by governmental regulations relative to the use, erection, and maintenance of electrical apparatus below ground. Those with which we are specially concerned are the regulations for the installation and use of electricity in the coal mines of Nova Scotia. The potential dangers of electricity in coal mines are: Shock or burns by contact from live parts. Shock or burns by contact with parts which, although normally dead, have become accidentally alive. Fire. Explosion of gas or coal-dust Explosion of apparatus.

Jan 1, 1928

By S. J. Schatzel, J. D. Addis, V. Gangrade

In longwall mining, ventilation is considered one of the more effective means for controlling gases and dust. In order to study longwall ventilation in a controlled environment, researchers built a unique physical model called the Longwall Instrumented Aerodynamic Model (LIAM) in a laboratory at the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) campus. LIAM is a 1:30 scale physical model geometrically designed to simulate a single longwall panel with a three-entry headgate and tailgate configuration, along with three back bleeder entries. It consists of a twopart heterogeneous gob that simulates a less compacted unconsolidated zone and more compacted consolidated zone. It has a footprint of 8.94 m (29 ft.) by 4.88 m (16 ft.), with a simulated face length of 220 m (720 ft.) in full scale. LIAM is built with critical details of the face, gob, and mining machinery. It is instrumented with pressure gauges, flow anemometers, temperature probes, a fan, and a data acquisition system. Scaling relationships are derived on the basis of Reynolds and Richardson numbers to preserve the physical and dynamic similitude. This paper discusses the findings from a study conducted in the LIAM to investigate the gob-face interaction, airflow patterns within the gob, and airflow dynamics on the face for varying roof caving characteristics. Results are discussed to show the impact of caving behind the shields on longwall ventilation.

By Jehan Rondot, Raymond Marleau

"Des quartzites trés pars ont été découverts au cours de la cartographie de la region du lac des Martres, étape de l'étude géologique de la region de Charlevoix.On distingue quatre groupes métasédimentaires, tons con tenant des niveaux de quartzite dans an mains deux domaines géologique différents, c'est à l'ouest, clans le do¬maine gneisso-charnockitique que se situent les quartzites du groupe des Martres. Quartzite et gneiss à, grenat et sillimanite, en banes épais, constituent la formation de La Galette. A Pest, dans un environnement gneisso-granitique, les deux groupes métasédimentaires de Saint-Siméon, et de La Malbaie comprennent, par contraste, des bancs pen épais et de compositions variées. Les niveaux de quartzite dépassent rarement 50 m d'épaisseur. L'autre groupe métasédimentaires, celui de Saint-Tite des Caps, recoupé de nombreuses intrusions charnockitiques et granitiques, ne possède que de minces niveaux de quartzite.La pureté et la grande épaisseur des quartzites de La Galette suppose une histoire complexe qui se termine par des depots continentaux de climat aride, par opposition aux depots marins des autres groupes. D'autre part, la presence de ces quartzites an sein de roches Presque anhy¬dres et de haute temperature que sont les charnockites leur confére des caractéristiques de fusion sans decrepitation.Parmi la multitude de depots de quartzite qui existe clans le monde, peu sont de qualité supérieure. Or, de par sa composition chimique, le quartzite de La Galette se compare avantageusement à ceux des meilleurs gisements des Etats-Unis, de l'Europe de l'Ouest et de l'Afrique du Sud. D'accès facile pour l'exploitation, les gisements ne sont qu'à une trentaine de milles de Baie Saint-Paul ou de La Malbaie, sur le Saint-Laurent.L'utilisation en metallurgic prévue pour le quartzite de La Galette comprend la production de silicium, de ferro¬silicium et d'autres alliages de silicium. La composition du quartzite est en outre appropriée pour la production de carbure de silicium et de silicate de sodium. Les fines peuvent être utilisées pour la fabrication du verre et comme matiere de charge"

Jan 1, 1977