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By Shae K. Kim

The aim of this study is to manufacture magnesium alloys with alkaline earth metal oxides (BeO, CaO, MgO or SrO) additions with the objectives of (1) ensuring safety during processing and applications by raising the ignition temperature and reducing oxidation, (2) protecting the environment by reducing or eliminating use of protective gases, (3) maintaining or improving elevated temperature properties with lower amount of Ca or Sr or rare earth metals when compared with conventionally developed high-temperature magnesium alloys, (4) developing cleaner strip casting and continuous casting processes without hot tearing and (5) obtaining all of these objectives without sacrificing mechanical properties or increasing the cost of magnesium alloys.

Jan 1, 2006

By Yingbao Yang, Jinyue Liu, Yonggang Wei, Bo Li

Due to the depletion of copper ore with high-grade and low impurity contents, the raw materials for copper smelting exhibit low copper contents and high impurities. High-impurity elements lead to the poor performance of the final copper product; thus, the removal of impurity elements during the oxygen-enriched copper smelting process is crucial. In this study, based on the production of high-grade matte, the occurrence states of impurity elements (such as As, Pb, and Zn) are analyzed in the input and output materials of the oxygen-enriched smelting process, and the phase transformation mechanisms of impurity elements are revealed during the oxygen-enriched smelting process. The effects of temperature, Fe/SiO2 ratio and oxygen concentration on the distribution behaviors of impurity elements in dust, slag and matte and the removal rates of impurity elements in matte are clarified. The results show that the impurity elements mainly exist as As4, As4S4, As2O3, Pb, PbS, PbO, Zn and ZnS in dust, as FeAsO4, As2O3, FeAsS, PbSiO3, Zn2SiO4 and ZnFe2O4 in slag, and as As, FeAsS, PbS, PbO and ZnS in matte. High smelting temperature, low Fe/SiO2 ratio and low oxygen concentration are beneficial for improving the matte grade and the removal rates of impurity elements Pb and Zn in matte. Low smelting temperature, low Fe/SiO2 ratio and high oxygen concentration are beneficial for removing impurity element As in matte.

Aug 8, 2023

By E. Allen Wendt

It is both a great pleasure and something of a challenge for me to have this opportunity to address a gathering encompassing such a wealth of expertise in the minerals field, It is particularly challenging because I have been asked to turn your attention from the relatively glamorous subjects of gold and money to the more mundane questions of our International commodity policy and the place of buffer stocks in that policy. However, these questions may be of more immediate importance for our economic interests at home and Abroad. I can testify that the problems affecting international commodity markets and the possibility of international action To resolve those problems are matters of real concern to Washington as well as to your industries,

Jan 1, 1978

By J. H. Adkins

The goal of this program was to produce a set of baseline health and safety training materials that could be used by the metal/nonmetal mining industry to reduce injuries and to comply with federal training requirements. The materials developed are arranged in a two level outline format. The first level provides the title, course goals, background and topical outline while the second level provides a detailed outline of the course content. Visuals, designed to portray miners in a positive, attractive fashion, were done in simple line drawing so they would reproduce for handouts without loss of quality. Each of the required units in the Baseline Guides have one or more self-checks. These are designed to be suggestive of evaluation techniques the users can develop for themselves. An instructors guide and a mining terms glossary are included. In a second phase the program developed performance based training guides for Annual Retraining and Experienced New Hires in the Underground Salt Industry.

Jan 1, 1983

By Jorge Olivari Ortega

"El presente texto describe la historia del inca Huiracocha y la explotación con los filones de oro del Ritisuyo. Durante el proceso de expansión del imperio incaico, los dominios territoriales de Hatun Inca o ""Huiracocha, el octavo gobernante, alcanzaron por el sur, hasta la última población de las Charcas (en la actual República de Bolivia); por el oeste, hasta las orillas del Océano Pacífico; y por el oriente, hasta la Cordillera Nevada o Ritisuyo, donde existían riquísimos filones de oro. Así, los incas denominaron ritisuyo (de los términos quechua: riti, nieve y suyo, región) al espacio geográfico de los Andes que supera los 4,500 metros sobre el nivel del mar y está cubierto con nieves, donde muchas veces asoman o afloran filones de oro en su superficial. Los filones son depósitos de minerales con contenido aurífero que fueron explotados por los incas -particularmene por el corimayco (encargado del trabajo minero) a través de socavones, el cual consideraba la dureza del terreno y además, el curso de la estructura mineralizada (rumbo y buzamiento)."

Jan 1, 2016

By J. Seiter, S. Cox, E. Kim

Mining has always been among the most hazardous of occupations, and with the increasing demand for coal and minerals, safety in mines assumes even greater importance. Worldwide, underground miners are being exposed to noise and respirable dust hazards associated with roof bolt drilling. These hazards are now being understood to cause irreparable damage to the health of miners. The objective of this research was to discover if a polycrystalline diamond compact (PDC) drill bit generates less respirable dust and hazardous noise than a competing tungsten carbide (WC) bit in dry vacuum drilling. In order to control the drill parameters the drilling tests were conducted in a laboratory setting. The results were obtained by determining the quantities of dust and noise generated using each drill bit and analyzing those levels, using monitoring devices and software to collect the data. This paper includes information on the experimental setup, equipment used, drilling parameters, and data collected. Our results indicate that PDC bits produce significantly less noise and dust than WC bits. Our findings can contribute to improving the working conditions of rock bolter operators by reducing noise and dust generation.

Jan 1, 2014

By Augusto Cabrera La Rosa

El presente trabajo revisa el panorama sobre el proceso de clasificación y explotación de los recursos minerales no metálicos en el Perú, con el objeto de promover el desarrollo de la minería no metálica. Los metales de origen mineral se clasifican en cuatro grupos: metales en estado nativo y minerales metálicos, combustibles minerales, aguas subterráneas y un gran número de sustancias minerales que no están comprendidas en ninguna de las categorías mencionadas, y que constituyen el grupo de los no metíllicos, llamados también minerales y rocas industriales. Asimismo, se muestra la clasificación establecida por el código de minería (combustibles minerales, minerales industriales, refractarios, material de construcción y minerales no metálicos diversos). Luego se describe el valor de la producción nacional de minerales no metálicos, como la situación actual de la minería no metálica en el Perú. Concluyendo que el Estado debe priorizar la prospección de minerales no metálicos de acorde a la importancia del desarrollo del país, asi como estimular la iniciativa privada para el descubrimiento de nuevos depósitos de dichas sustancias comercialmente explotables.

Aug 20, 1963

By L. O. Howard

L. D. RICKETTS, New York, N. Y.-The advance which has been made in Smelting has been in the line of cheaper cost of handling, due to larger units and decrease in losses. At the International smelter, Mr. McGregor designed everything to handle the ore under cover. But we do find an unaccounted for loss of 0.7 per cent. of our copper, which is serious. Mr. Wallace has made a suggestion that I think metallurgists ought to know of and think about. He made it years ago-and that is that one of the chief losses is undoubtedly in the charging and discharging of the calcine cars. His idea is that possibly the dryers and heaters might be put immediately over the reverberatories So that they could discharge in conveyors. They could feed on both sides, and thereby the dust raised by discharging in the cars from the hoppers could be overcome. E. P. MATHEWSON, Anaconda, Mont.-I might Say a few words on the plants we have visited So far. I was particularly struck with the cleanliness of the plants, which is next to Godliness. I noticed also that the skull-cracker arrangement they have for handling their converter slag is very good. And they have paid considerable attention to ventilation, and are taking steps to take care of the health of the men. "Safety first" has been well looked after in all the plants we have visited so far. The steel structures are right up to date, and the buildings are of the most modern type, and everything is conveniently arranged. I think the designers of the plants in the Southwest are to be congratulated on what they have done.

Jan 12, 1916

By Varadarajan Seshadri

Geometallurgical characterization of iron ore which is a raw material for Iron making as in the case of charcoal blast furnaces operating in Brazil or for production of agglomerates such as iron ore sinter which serves as burden material for blast furnces of high productivity or pellets extensively used in the direct reduction processes all over the world in the iron and steel industry. Selection of proper raw material after due characterization should lead to an improvement of the productivity of the respective processes The usual classification of quality of iron ore is uniquely based on chemical analysis, granulometric and physical parameters. However not much emphasis has been given to the structural characteristics which also are important in the processes. Different typological categories of Brazilian iron ores have been used in the characterization . For instance, several kinds of hematite crystals like specularite, martite and microgranular hematite, etc with variable crystal sizes are found in the different ore types. They are also composed of different of fabrics and types of accessorial mineralogical constituents and have different porosities, pore diameters, etc which influence the cold and the hot agglomeration stages of the ore fines, and also chracteristics such as reducibility, decrepitation etc, important for assessment of quality of iron ores. . The first step for attaining a good characterization of ores is to know in detail about the structure of the deposit, shape of the body, types of iron ores and their distribution. This requires a geological-structural study and the mapping of the bodies using mineralogical criteria for typological classification of ores. followed by structural characterization of materials in stages of mining, comminution, screening and concentration processes. In this contribution a geometallurgical approach for quality control of Brazilian iron ores for sintering and pelletizing processes is highligted.

Jan 1, 2006

By L. Yuan, R. A. Thomas

"Atmospheric monitoring systems (AMS) have been widely used in underground coal mines in the United States for the detection of fire in the belt entry and the monitoring of other ventilation-related parameters such as airflow velocity and methane concentration in specific mine locations. In addition to an AMS being able to detect a mine fire, the AMS data have the potential to provide fire characteristic information such as fire growth — in terms of heat release rate — and exact fire location. Such information is critical in making decisions regarding firefighting strategies, underground personnel evacuation and optimal escape routes. In this study, a methodology was developed to calculate the fire heat release rate using AMS sensor data for carbon monoxide concentration, carbon dioxide concentration and airflow velocity based on the theory of heat and species transfer in ventilation airflow. Full-scale mine fire experiments were then conducted in the Pittsburgh Mining Research Division’s Safety Research Coal Mine using an AMS with different fire sources. Sensor data collected from the experiments were used to calculate the heat release rates of the fires using this methodology. The calculated heat release rate was compared with the value determined from the mass loss rate of the combustible material using a digital load cell. The experimental results show that the heat release rate of a mine fire can be calculated using AMS sensor data with reasonable accuracy.IntroductionFires at different stages generate different gases and smoke toxicity hazards. When fires occur in underground mines, a significant amount of toxic gases and smoke enter the mine ventilation system and are carried throughout the mine ventilation network, increasing the hazard potential for personnel even if far away from the actual fire. Although fires that develop to the point of rapid flame spread pose imminent hazards, fires in their smoldering, pre-flaming stages can also contaminate the mine atmosphere with debilitating levels of smoke and toxic gases.The most important parameter for evaluating the fire hazard in mines is the heat release rate (HRR), which is directly related to the rate at which heat, smoke and toxic gases are produced and transported by the ventilation system and which provides an indication of the time available for escape or firefighting (Babrauskas and Peacock, 1992). The HRR is also an important input parameter to mine fire simulation models."

Jan 6, 2017

By Kenneth E. Merklin

The heavy media process is now being used extensively throughout the world for the gravity concentration of a great number of different minerals. The process is a commercial adaptation of the heavy liquid procedure which has been used in laboratories for many years to separate mineral of different specific gravities. In the heavy media process, a suspension of finely divided particles in water is used to increase the apparent specific weight of the fluid to the desired separating point. The original heavy media process used sand, galena, pyrite and occasionally other materials as the solid constituent of the separating suspensions. As the process developed, the need for a more universal media meeting the following requirements was recognized: 1. High specific gravity. 2. Resistance to abrasion. 3. Resistance to corrosion, 4. Readily reduced to a suitable size consist for suspension in water. 5. Available in quantity at economical price levels. 6. Easy to recover by a simple method.

Jan 1, 1958

It is well documented that drill and blast outcomes affect the downstream mining processes of loading, hauling, crushing and grinding but it can also significantly impact on mine profitability via dilution, recovery percentage, lump generation (iron ore), fines generation (coal, iron ore), coal loss and final wall stability. Drill and blast must therefore be optimised to improve the overall profitability via positively impacting on productivity and saleable product generation. It is however, difficult to achieve this because of the complexity of the number of parameters that must be integrated and managed across the entire mine value chain, ie the concept of æMine to MillÆ. This paper highlights, via a simple case study, the need to have a mineÆs drill and blast system both in control (so that it is predictable to a high degree) and with minimal variability (so the design actually makes it into the field). This type of management control is essential prior to optimisation work being undertaken. The æTeam ApproachÆ is discussed to illustrate the methodology of achieving drill and blast optimisation. A case study is presented to illustrate the potential benefits of this approach which in this mine represented a 27 per cent reduction in powder factor with the downstream functions achieving higher productivity with the same or reduced maintenance costs. It is essential for Australian mineÆs to implement the appropriate management strategies and experienced personnel placement to ensure that their mineÆs drill and blast system is correctly managed to facilitate the optimisation of profit. Without this, the Australian mining sector will become increasingly uncompetitive.

Jan 1, 1999

BIRINGUCCIO was born in Siena in 1480, the son of Paolo and Lucrezia di Bartolommeo Biringuccio.* He was baptized on October 20 of that year with the given names Vannoccio Vincenzio Austino Luca. His father appears to have been an architect, for in 1504 he was paid 600 scudi for his work on the walls of the Communal Palace and at the same time he was superintendent of streets for the city. The course of Biringuccio's life followed closely the checkered fortunes of the Petrucci family of Siena. A warm supporter of Pandolfo Petrucci, Biringuccio did not falter in his allegiance to the family and their party during his lifetime. It was probably to the protection and patronage of this lord that he was indebted for the opportunity to travel widely through Italy and into Germany during his early years and so to lay the foundation for the extensive knowledge of the subjects he was to describe in the Pirotechnia. In 1507, as he himself indicates (p. 48), he was 'in Friuli and. Carnia in northern Italy after having traveled in Germany,, and he also visited the, brass, works in Milan. After returning to Siena; he was sent by Pandolfo to direct the iron mines in near-by Boccheggiano. When Pandolfo died in 1512 (in which year Biringuccio's s father also died), Biringuccio continued to support the Petrucci family in the person of Pandolfo's son, Borghese, who succeeded, to the rule. Under his patronage, Biringuccio was appointed to a post in: the Armoury of the Siena Commune in 1513. In ISIS a popular uprising forced Borghese and his followers, including Biringuccio, to flee from Siena. Biringuccio and the goldsmith Francesco Castori, head of the mint, were accused of having debased the coinage alloy with the knowledge and consent of Borghese. When he failed to appear in 1516 to answer these charges-which may well have been invented by the opposing political faction-Biringuccio was declared a rebel and was exiled as a traitor to the Republic. He then traveled about Italy, was in Rome and Naples, and visited Sicily in 1517.

Jan 1, 1942

By VIVEK KUMAR HIMANSHU, Murari Prasad Roy, Kaushik Dey, Rakesh Kumar Singh, Ashish Kumar Vishwakarma

Sublevel stoping is the most popular and practiced mining method in underground hard rock mines. Proper planning and its execution is the key requirement for stope extraction using this method. The stope extraction has been a challenging task since decades. The major reason is the unavailability of free faces as compared to opencast bench blasting. The geological and geotechnical parameters change gradually even within the stope itself. So, the blast design parameters should be planned according to the scenario of the upcoming ring. The blast design parameters like burden, toe spacing, inclination of blastholes, diameter of blastholes, charge density of explosive, etc., play an immense role in the rock damage. For the proper breakage of rock, the movement of burden is the prime objective. To study this, an explicit dynamic based modeler of M/s Ansys was used. The burden values were varied from 20 to 65 times of blasthole diameter to assess the optimum burden value during the study. The models were simulated for the rock having uniaxial compressive strength as 35 MPa and 102 mm blasthole diameter. Three holes were simulated having depth around 14–14.5 m. Different blast design parameters and respective blast-induced ground vibration have also been measured at the experimental site. The core samples of the rock present at the experimental site have been used for the evaluation of geotechnical parameters. These geotechnical parameters were used in the simulation models. The volume of rock excavated along the free face has been calculated in each model by varying the burden. It has been found that the burden value can varies from 35 to 40 times blasthole diameter (3.6–4.1 m) to achieve a greater volume of rock along the free face for 102 mm blasthole diameter and rock of 35 MPa uniaxial compressive strength.

Dec 22, 2023

Case I- Timber Pile Test- 4 pages describe the pile driving record, the pile load test and the boring log. Case II- 24 inch square prestressed concrete pile-5 pages give details about the pile driving, the boring log, the pile driving record, and the pile load test. Case III- 12 inch square prestressed concrete pile- 5 pages describe the compilation of SPT blow counts for the whole project, the pile driving record, the pile load test and the detailed boring logs. The 70 foot long pile was driven by a Vulcan 08 pile hammer. Case IV- 12 BP 53 Steel H pile- 3 pages give the pile load test, the pile driving record and the nearest boring log. The 64 foot long pile has its tip at elevation 908 ft. and the ground is at elevation 972 ft. The contractor augered to elevation 959 ft. before driving the pile with a Conmaco 08 single acting pile hammer. The hammer had an 8000 pound ram, a rated energy of 26,000 ft-1b., and a 7 1/2 inch thick asbestos cushion. Dynamic measurements were made during driving of the test pile and measured a hammer energy equal to 12,500 foot-pounds.

Jan 1, 1988

By John Ward Smith

The potential economic value of oil shale depends on the products from thermal degradation of the rock, because no other practical method for producing valuable material from oil shale has been found. Detailed study of thermal degradation behavior can aid in characterizing oil shales and their deposits and in evaluating oil-shale processing methods, Numerous publications describe various pyrolysis properties of oil shales (see surveys 3, 9, 11 and articles 1, 2, 4-8, 10, 12),4 but they do not describe a generally applicable analytical procedure for detailed evaluation of thermal degradation products. The analytical method presented here for such evaluations is designed to provide for: 1. Control of retorting conditions--temperature, heating, rate, reaction atmosphere--plus some control over retort pressure and carrier-gas flow, 2. Precise direct gravimetric measurement of the thermal degradation products--oil, water, gas, and spent charge (residue after thermal treatment of the charge). 3. Samples of all products. 4. Determination of the identities and amounts of gaseous compounds produced. 5. Elemental analysis and gross heating value of all products. 6. Determination of the distribution in the retorting products of the elements present in the original samples.

Jan 1, 1962

By Marcela Alves Silva

Aços inoxidáveis são ligas Fe-C-Cr com elevada resistência à corrosão. Estes podem receber diferentes elementos de liga, que alteram suas microestruturas e propriedades de acordo com o interesse da aplicação. Os mais comuns são os austeníticos, ferríticos, martensíticos e duplex. Os aços inoxidáveis austeníticos possuem excelente resistência à corrosão, elevada ductilidade, boa soldabilidade, conformabilidade e tenacidade. Os aços inoxidáveis ferríticos possuem boa resistência à corrosão, são bons para estampagem e possuem maior dureza e soldabilidade em relação aos austeníticos. Os aços inoxidáveis duplex (AID) são aços com estrutura bifásica, formados pelas fases ferrita e austenita, em proporções de aproximadamente 50% de cada. Os AIDs apresentam associação de resistência mecânica com resistência à corrosão. O presente trabalho tem como objetivo realizar ensaios metalográficos e tração de um AID 399B, de um aço inoxidável ferrítico 441A e de um aço inoxidável austenítico 304N, para fins de comparação da microestrutura e propriedades mecânicas. Com os resultados conclui-se que o AID possui maior resistência à dureza na escala HRB, o aço austenítico possui maior capacidade de alongamento, devido sua estrutura CFC. Já o limite de resistência e de escoamento são maiores no aço AID devido a sua maior proporção da fase ferrita (52%).

Aug 17, 2017

By Atta Ur Rehman, Kwame Awuah-Offei

"Information diffusion potential of a social media user affects how quickly information about a mineral project can diffuse through that user. If management can use social media and network analysis in community engagement programs to understand how fast and how far information will diffuse to communities and followers of particular social media users, it can selectively focus on the most influential users. This article proposes a method to examine the information diffusion potential of social media accounts. The work uses Gephi, an open source software, to extract and analyze data from different Twitter handles to predict their information diffusion potential. The work uses case studies of real Twitter users (e.g. mining news organizations and bloggers) associated with mining to illustrate the approach. The case study results show that there are significant disparities in information diffusion potential that will demand selective attention. This research will help mines develop effective social media engagement strategies.The mineral industry provides raw material for industrial activity to support society (Martens and Rattmann, 2001). Mines have changed from conventional mining practices to sustainable ones because of the negative impacts of mining in the past and increased public awareness (Wang et al., 2016). The concept of sustainable mining is getting mature, as stakeholders (e.g., governments, investors and host communities) are getting more involved in mining projects (World Economic Forum, 2014). The failure of mining companies to address the demands of these stakeholders might result in the failure to acquire a social license to operate (SLO) (Thomson and Boutilier, 2011). The SLO, if granted, is mutually beneficial to all stakeholders. Mines prefer being granted SLO and keeping it to avoid any kind of social unrest due to their operation (Prno, 2013; Moffat and Zhang, 2014). Mining communities can grant different levels of SLO ranging from withholding SLO to psychologically identifying with the project (Joyce and Thomson, 2000; Thomson and Boutilier, 2011).Most of the previous work to understand community perceptions and SLO in mining is generally qualitative (ICMM, 2012a; Thomson and Boutilier, 2011; Prno, 2013; Moffat and Zhang, 2014; IFC, 2014). In particular, there is limited work on how community perceptions change over time due to information diffusion (Boateng and Awuah-Offei, 2017). However, SLO changes with respect to time (Yates and Horvath, 2013), which can result in risks that are not easy to predict. Mine managers and engineers have a desire to understand these changes so as to mitigate these risks (Que and Awuah-Offei, 2014; Que et al., 2015)."

Jan 4, 2018

By Rudolf Keller

In the electrolysis of neodymium oxide from a molten fluoride electrolyte, anode effects may occur at the carbon anodes, interfering with smooth cell operation. In laboratory experiments, we attempted to circumvent this problem by selecting electrolytes with a high oxide concentration, possibly at relatively low rare earth content, but cathodic deposition was not satisfactory. A regime at higher cell voltage was discovered to yield good cell performance, but evolution of considerable amounts of fluorocarbon compounds suggested that a reactive treatment of the off-gases would be necessary for environmental acceptability. Subsequent experimentation at low cell voltage revealed conditions for satisfactory operation without occurrence of anode effects and without formation of any CF4 or C2F8.

Jan 1, 1997

By D. Harrington

Fine ventilation was discussed. much more 15 to 20 years ago than it is now, yet today there are tendencies in connection with ,-line ventilation (in fact, numerous ventilation systems have been installed in recent years) indicating that the lessons learned by bitter experience in the past either have been forgotten or lave not been brought to the attention of the present generation. Possibly, the mining min of today considers that conditions have changed so much that experiences of the past cannot be repeated today. At any rate, it seems desirable to restate some of the principles of mine ventilation that were understood more or less in the past and to call attention to some danger in connection with present-day trends or practices.

Jan 1, 1939