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By Raymond L. Carpenter

The thermal conductivity, electrical resistivity, and Seebeck coefficient for nine compounds, based on the formula for enargite Cu3AsS3, were measured in a search for efficient materials to be used in thermoelectric generators or refrigerators. Results indicate that one of these compounds, Cu3SbSe4, has thermoelectric properties approaching those of bismuth telluride. An investigation of the effect of adding small quantities of tellurium to Cu3SbSe4 and Cu3SbS4 in order to improve their properties also was made. A figure of merit of 2.1 x 10-4 °C-1 was obtained for Cu3SbSe4 + 0.1 percent tellurium.

Jan 1, 1963

By Elio Flórez

El presente trabajo refiere la utilización práctica de las escorias metalúrgicas -en tanto material de aislamiento térmico-. La lana de escoria es conocida como "lana mineral", cuya industria se inició en 1897. La manufactura suelta no es el producto final, sino la materia prima, que será tratada en un proceso seco para obtener las diferentes formas de productos y adaptarlas a distintos usos. La lana de escoria puede ser usada como aislante térmico, en absorción de sonido y también como medio de filtración y material de relleno. En el primer caso, se utiliza en casas y edificios, hornos, duetos de aire acondicionado, salas frigoríficas para alimentos, tanques de agua caliente, calderos, intercambiadores de calor, tuberías, etc. Mientras que en el segundo caso se utiliza para extraer polvo, agua de aire o gases. Asimismo, los productos de lana de escoria son la granulada, acolchada en mantas, en bloque, en planchas comprimidas, en formas moldeadas, las cuales tienen una densidad instalada desde 2-lb/pies3 en las formas más-79- livianas, hasta 16 lb/pies 3 en las formas semi-rígidas.

Aug 20, 1963

By R. L. Garrett

The quality of mineral additives used 1n a drilling fluid (mud) can dramatically affect the fluid's properties and the overall cost of drilling an oil or gas well. The principally used minerals are bentonite, barite, barite/hematite blends and hematite alone. The high specific gravity minerals, barite and hematite, are used to increase drilling fluid density. Bentonite clay is used to increase drilling fluid viscosity, gel strength and to provide a low permeability filter cake. A multi-million dollar investment in a well and the safety of the personnel on the drilling rig can depend on how effectively these mud additives perform with other constituents in the mud. This paper points out effects caused by small amounts of certain carbonate and sulfide mineral impurities in barite or hematite and how polymeric extender additives in bentonites contribute to unpredictable behavior of a mud. Effects like these are the reason why oil companies who use these materials sometimes set their own quality standards beyond those already specified in API Spec. 13A. Also discussed in this paper are the current standardization activities in API Committee 13 on these minerals.

Jan 1, 1986

By E Lima, D Gregory, C Faria, A Lapworth

Open pit mine enterprises are complex systems that depend on multiple parameters such as mineral grade distribution, geotechnical characteristics, economic conditions and engineering requirements, all of which vary in time and space with a different degree of uncertainty. The unpredictable nature of these inputs imposes a risk to mine owners and shareholders which in the worst case can lead to highly undesirable financial outcomes.Desktop studies commonly examine a set of scenarios based on adjusting variables such as commodity prices, mining costs, processing costs, and metal recoveries to understand their relative impact on the economics of a project. It is less common to systematically explore and simulate hundreds of alternative physical designs to understand and compare the financial risk associated with one or more mining projects.This paper presents a risk assessment tool set and methodology that uses web based cloud computing to enable multiple simulations of mine designs to be rapidly and efficiently executed. The methodology includes generating random sets of prices and costs values within their respective probability distributions. Pit designs are then created to maximise the profit for each set of input variables. Various approaches to analysing the results are discussed. Use of the same high performance computing environment for understanding the financial risk associated with the variability of the underlying geological resource model is also discussed, with provided examples using case studies from two of the major mineral producers.CITATION:Lima, E, Gregory, D, Lapworth, A and Faria, C, 2014. Simulating extraction shapes to understand financial risk using high performance computing, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 351–360 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By Raja V. Rarnani, Robert L. Frantz

"The Generic Mineral Technology Center for Respirable Dust (GTCRD) was created at The Pennsylvania State University and West Virginia University by a congressional initiative in 1983 responding to recommendations in the 1980 National Academy of Sciences study on the Measurement and Control of Dust in Mines. Many of these recommendations dealt with the need to initiate focused fundamental research for further professional progress in dust control. Long-term, sustained support was emphasized to develop expertise in respirable dust research. In creating this Center, Penn State and West Virginia University were specifically recognized for their expertise in and facilities for research on coal mining and medicine. Today, the Center includes the Massachusetts Institute of Technology, the University of Minnesota, and the Michigan Technology University. The Respirable Dust Center is the only organization that coordinates and integrates the medical, scientific, and engineering aspects of respirable dust disease. The Center works with the U.S. Bureau of Mines (USBM), Mine Safety and Health Administration (MSHA), the National Institute for Occupational Safety and Health (NIOSH), the United Mine Workers of America (UMWA), and the U.S. coal industry in defining the research priorities for the programs of the Center to enhance research synergism.The Center's mission is to enhance the health, safety and productivity of miners by advancing the fundamental understanding of all aspects of respirable dust associated with mining and milling and the interaction of dust and lungs to reduce the incidence and severity of respirable dust disease.All Dust Center activities are focused to be responsive to this mission, which is shared by the several federal agencies closely associated with the GTCRD. While significant progress has made mine atmospheres cleaner and healthier, respirable dust-related disease remains the nation's most pernicious industrial hazard.The goals of the GTCRD were formulated with recognition of the diverse scientific, engineering, and medical aspects of respirable dust, in addition to a need to enhance researcher interaction, as well as education and technology transfer efforts, in the respirable dust area. These goals reflect the needs of the mining industry as determined by the National Academy of Sciences Committee on Measurement and Control of Respirable Dust study done in 1980. The report of this committee encouraged the Bureau of Mines to redirect its research efforts ""...toward obtaining fundamental understanding of the origin, transport and characteristics of respirable coal mine dust."" The GTCRD's goals, detailed in chapter three of this document, were formulated to mesh with NAS recommendations."

Jan 1, 1995

By Jian Li, Tiejun Chun, Jian Pan, Deqing Zhu, Vinicius Mendes

"A study of the coal-based direct reduction behaviors of composite binder magnetite pellets was carried out in a simulating coal-based grate-rotary kiln process. It is shown that preheated pellets possess much better reducibility than fired oxide pellets: 40 min are required for preheated pellets to reach over 90% metallization degree compared to 100 min for fired oxide pellets. The compressive strength of preheated pellets decreases dramatically at the earlier stage of reduction, climbs quickly after reducing for 30min and achieves a high value at the end of reduction. However, the compressive strength of metallized pellets from reducing of fired pellets is much lower, more cracks and fractures being formed. In the preheated pellets, crystallite of metal iron is coarse. In the oxide pellet, a large number of interconnected crystals of metal iron are formed inside pellets, and pellet structure is very compact.IntroductionDirectly reduced iron is an excellent feed in electric arc furnace (EAF) steelmaking, and possesses low tramp element content and steady component. It is generally preferred in the production of high quality steel [1-3]. Nearly 64.44 million tons of DRI were produced in 2009 over the world, over 80% of which were produced by gas-based processes, the left by coal-based processes. However, the DRI capacity was only 600 thousand tons in China in 2009. The EAF steel production has exceeded 40 million tons annually, and most of EAF operate on hot metal as feed [4]."

Jan 1, 2011

The ventilation conditions at the underground coal mines are influenced; first: by the disturbances of the natural nature (barometric pressure, methane liberation, etc.), and second: by the disturbances caused by the production process. The major goal of this study was to determine the changes of the ventilation parameters, such as the flow, pressure and methane concentration around the longwall panel, particularly, along the longwall face due to the shearer operation (motion). It is well known from the practice, that the movement of the shearer influences the ventilation parameters around the longwall panel, including the gob area. Until now, these data were gathered in a single or multiple locations at the different time. However, only the simultaneous measurements of all of these values allow seeing the time dependent interrelationships between measured parameters. To be able to show these interrelationships, special experiments, described in this paper, were carried out by the author. These experiments were prepared and executed at the BUDRYK Coal Mine in Poland. During each experiment a simultaneous measurements and monitoring of the barometric pressure, air velocity and methane concentration at the different locations along the longwall face, were performed. The investigation was possible by using a special setup of instruments with a short sampling time, i.e., within 2 seconds. The monitoring of the absolute pressure was conducted by using the digital barometer µBar, developed by EMAG, based on the SETRA pressure transducer, model 470. The velocity of air was measured using the electronic vane-anemometers, developed by IMG-PAN. The methane concentrations were measured using methanometers as the part of the EMAG automatic gas monitoring system. The investigation data confirmed that disturbances due to the operation (motion) of the shearer at the longwall face have a local character. It could be also seen that a large diameter shearer (compared to the total cross-section area available for the air flow) is acting as the piston compressing the air (the overpressure) ahead of the shearer. This fact affects the methane mixing process and flow patterns in the vicinity.

Jan 1, 2009

By D Brown, K Markovic, Z Tabor

From ancient times to the modern world, the mining industry has played a pivotal role in shaping the society that we live in today. It remains an integral part of everyday life and is a catalyst for both technological and economic growth. With finite resources on Earth, and growing pressures surrounding climate change and the environment, space mining opportunities have become of increasing interest. Recent discoveries have shown celestial bodies including the Moon and surrounding asteroids, contain an abundance of critical minerals, as well as resources necessary to sustain human life. These discoveries coupled with a transition into the digital and autonomous age, offer an innovative solution to solving some of the mining challenges currently being faced on Earth. Similarly, they also offer a pathway to enabling deep space exploration and off Earth exploratory missions. However, like with mining operations on Earth, space remains and immensely challenging and complex operational environment. The inhospitable nature of space poses new challenges, including communication barriers, lunar dust, cosmic radiation, and gravity. The challenges and risks are not just technological, as Environmental, Social, and Governance (ESG) factors must also be considered to prevent unintended consequences and hazards. Furthermore, future workforce, law, financial, and security systems must evolve to enable space mining to take place. These are all known aspects to begin with, but as the complexity of the space grows it becomes apparent that a holistic approach to assess and manage these factors will be required.

Sep 1, 2024

By Rolph Linder

It is generally known and accepted that the efficiency of the blast furnace process, expressed by the symbols specific production and coke consumption, is influenced by a large number of variables connected to the type of burden, the alloy contents of the produced iron and the conditions of production as composition and preheating of the blast, the furnace heat losses and the possible use of fuels added on the tuyere level. It is furthermore obvious, that the coke consumption of the process will be influenced by specific production which could be said to be the result of two counter-acting influences. With high production, realized through intensive blowing, the passage time of the ore through the furnace is shortened leading to a decrease of the indirect reduction taking place in the upper part of the shaft within the temperature range of 300 to 1000°C. Simultaneously the external heat losses (constant in time) will be smaller calculated on each ton of iron and the resulting change in coke consumption will be the effect of both those influences. It is certainly of interest to be able to predetermine the effect of those variables before a change in the production practice is carried out.

Jan 1, 1964

By D. C. Fleck

This report describes a method of using sodium for reducing titanium tetrachloride, developed at Boulder City, Nev., as part of the Federal Bureau of Mines effort to improve the extractive metallurgy of titanium. Finely divided titanium metal, titanium lower chlorides, or a mixture thereof was produced in a continuous operation at temperatures between 105° and 205° C. by the reaction of molten sodium and vaporized titanium tetra-chloride in an agitated bed of finely divided inert solids (powdered sodium chloride or the reaction products). Composition of the product was controlled by varying the relative quantities of sodium and titanium tetrachloride used. A description of the operations and analytical data of the reaction products are given.

Jan 1, 1960

By E. L. Litchfield

Spark ignition of combustible-gas mixtures is a relatively old subject of investigation and has been treated both experimentally and analytically by many people. Elements of static and current electricity are almost always present in mining and industrial operations, and the spark can be an extremely efficient source of ignition. Thus the practical interest of such problems as the "intrinsic safety" of electrical apparatus is obvious. Ignition and quenching phenomena are the primary laboratory representatives of combustion phenomena that are dynamically nonsteady, and such nonsteady phenomena playa considerable part both in industrial processes and in safety matters, although they are of less immediate practical interest. Considerable effort has been expended by the Federal Bureau of Mines in investigations of spark ignition.5 6 7 8/ Primarily, this work has established the significance of several of the parameters involved. Although the

Jan 1, 1959

A nuclear technique utilising the gamma-ray resonance scattering process is used at Isa Mine for the determination of copper in drill core and bulk mineral samples. The Copper Bulk Analyser (CBA) provides quick and accurate non-destructive copper analysis of drill core at costs two to three times cheaper than conventional chemical techniques.The almost immediate availability of sample results enhances the efficiency of the mine geologist in the duties of grade control, design of diamond drilling programmes, and input to planning. The unit has proven to be a reliable and accurate production tool requiring a minimum of technical support.

Jan 1, 1990

By Jaisen Kohmuench, Michael J. Mankosa

Flotation has long served as the foundation for sulfide mineral recovery. As ore grades decline, however, this traditional approach is being pushed to the limit. Nowhere is this more evident than in the challenge of recovering coarse, partially liberated particles — an area where conventional flotation systems typically underperform due to excessive turbulence. As a result, valuable coarse minerals are often lost to tailings. Fine grinding has become the default solution, although with the added burden of higher operating costs and more challenging tailings disposal. To address the challenge of coarse particle recovery, Eriez developed the HydroFloat, a technology that uses a novel fluidized-bed approach to extend the upper particle size range of flotation significantly. The HydroFloat can recover particles exceeding 0.5 mm in diameter with a sulfide surface expression as little as 2 percent. Coarse particle recovery allows for optimization of comminution circuits for coarse gangue rejection before fine grinding. A substantial increase in overall tailings particle size provides higher water recovery due to improved drainage and allows for consideration of a dry, stacked tailings option instead of a tailings dam/impoundment. The technology’s transformative potential has not gone unnoticed. In recognition of its impact, Eriez was honored with the 2024 Robert E. Murray Innovation Award, commonly referred to as the Murray Award, by the Society for Mining, Metallurgy & Exploration. This prestigious award was established in 2017 to recognize organizations that advance the mining industry through the implementation of technical innovation. The HydroFloat stands as a fitting example of how creative thinking and industry collaboration can solve long-standing technical challenges.

Oct 1, 2025

By C. Guney Olgun, Mohammad Khosravi, Daniel W. Wilson, Deepak Rayamajhi, Scott A. Ashford, Shuji Tamura, Ross W. Boulanger

"Dynamic centrifuge tests were performed on unimproved and improved soil with soil-cement column models. The reinforcing effect of isolated soil-cement columns for reducing liquefaction potential and ground deformation in improved soil were investigated. This paper presents the observed acceleration, pore pressure, and settlement responses under an earthquake base motion for both unimproved and improved soil models. In addition, lateral reinforcing effects of soil-cement columns were also investigated in terms of site stiffening effects and the increasing natural frequency of improved soil. The test results show that the soil-cement columns were rather ineffective in preventing liquefaction triggering in improved soil and in significantly reducing the magnitude of the resulting soil settlement compared to the model with unimproved soil profile. Furthermore, the predicted natural frequency of the improved soil profile estimated using existing design equations is shown to be significantly higher than the observed natural frequency inferred from centrifuge tests results. These design equations assume shear strain compatibility between the columns and the surrounding soil. On the other hand, revised design equations that account for shear strain incompatibility between column and surrounding soil are shown to give reasonable estimates compared to the observed natural frequency of the improved soil model.INTRODUCTIONGround improvement using stiff columns (e.g., stone columns, deep-soil-mixing columns, and jet-grout columns), are often used in practice to reduce liquefaction potential (and associated deformations) in loose soil sites. Typically, saturated silty soils are difficult to densify or drain rapidly due to their lower hydraulic conductivity, so densification and drainage techniques of improvement are often found to be ineffective. Instead, the shear reinforcing mechanisms of stiff columns are considered effective for reducing the seismic stresses and strains, and thereby reducing liquefaction potential in the enclosed saturated silty soils (Baez 1995, Adalier and Elgamal 2004, Mitchell 2008)."

Jan 1, 2015

By D. Ofstie, B. Kargutkar

BIM, or Building Information Modeling, is transforming the way metallurgical facilities are built, operated and maintained. BIM provides a digital representation of the facility, complete with all physical and functional characteristics - enabling collaborative planning, concurrent design, construction simulation, sustainable operations and predictive maintenance through a connected information model. Building on experience gained in other industries, Hatch is aggressively applying the BIM process to the mining & minerals processing industry to address inefficiencies inherent in traditional document-based information management. Intelligent 3D models support real-time quantity forecasting and cost trending by commodity type and construction work package. By linking procurement and schedule data, material availability and constructability reviews are visualized to verify construction critical path, ensure work front safety and minimize craft downtime. The BIM digital information model connects engineering, construction, commissioning and vendor data, aiding timely asset-centric handover to plant operating and maintenance systems.

Jan 1, 2015

By Peter Lighthall

What is an engineering firm?s role? ? The ideal situation is a life of mine service alliance with the owner ? Engineering firms are long term custodians of information ? Maintain consistency with established closure objectives, adjust closure plans to meet changing situations and technologies ? Develop range of solutions and present owners with risk profile The mine closure planning process ?new mines ? For metal mining, geochemistry is the issue ? The planning process: ?Sampling ?Waste characterization ?ARD prediction ?ARD control strategies ?Life of mine waste management planning ?Assessment of residual impacts ?Development of strategies for dealing with residual impacts ?Estimate closure costs ?One time decommissioning and reclamation costs ?Ongoing treatment/maintenance costs

May 1, 2006

By Carlos Maurício F. Vieira, Lázaro A. Pizatto, Marcus Paulo Cardoso, Sergio Neves Monteiro, Joao Victor C. Nunes, Gustavo S. R. Matheus, Frederico M. Margem

The interest in composites with natural fibers is due, among other factors, to the growing worldwide concern with the preservation of environment and renewable raw materials. The natural fibers have many particular properties that make them an attractive alternative to traditional synthetic fibers. The advantages of using these fibers are: low cost, renewability, biodegradability, low toxicity, abundance and specific strength. The searching for new suitable, economically viable and technologically advanced materials justifies the accomplishment of this work that aims at comparing the mechanical behavior of polyester matrix composites with epoxy matrix composites reinforced with hemp fibers Izod impact tested. The specimens with dimensions: 10 63 12.7 mm, made in different volume fractions of fiber: 0–30 vol%. The samples were tested at PANTEC pendulum model XC-50 located at LAMAV/UENF. With this research was possible to analyse the mechanical properties of these two new materials.

Mar 1, 2018

By C. Chu

A theoretical investigation has been made of the forward combustion process using a one-dimensional linear mathematical model, taking into consideration the effect of the vaporization-condensation which occurs on the leading edge of the heat wave. This work involves the solution of five coupled partial differential equations. Besides the vaporization-condensation phenomenon, these equations account for conduction, convection, combustion, heat loss, diffusion and bulk fluid flow. For the one-dimensional linear model studied, the vaporization-condensation phenomenon does not induce appreciable change in the temperature at the combustion front; and its primary effect is to create a steam plateau and to increase the length of the heated zone ahead of the combustion front. This effect becomes more pronounced at lower pressures, higher porosities or reduced gas saturations. The peak temperature and the temperature profile on the leading edge of the heat wave stabilize after a certain period. The length of the steam bank remains practically constant, although the length of the water bank increases as the heat wave advances. INTRODUCTION The existence of the vaporization-condensation phenomenon in the heat-wave process and the important role played by the phenomenon have been recognized by several investigators. Kuhn and Kochl stated that steam plateaus were frequently observed on the temperature records of their experiments. The steam plateaus were attributed primarily to the vaporization and subsequent condensation of the interstitial water existing in the oil sand. Szasz2 suggested that both lighter hydrocarbons and water are vaporized on the leading edge of the heat wave, carried forward in the gas stream, and then condensed to create banks of oil and water. Martin et al suggested that the vaporization-condensation phenomenon is one of the main mechanisms of the heat-wave process, along with thermal expansion and viscosity reduction. Wilson et al. reported the existence of a steam plateau several inches in length in their small-scale tube-run experiments. However, this important phenomenon has never been taken into consideration in the numerous theoretical analyses by various authors. 5 The purpose of this work was to study the thermal aspects of a linear heat wave, taking into consideration the vaporization-condensation on the leading edge of the wave, to determine the effect of this phenomenon on the temperature profile of the reservoir, and to investigate how this effect varies when other process variables are changed. THEORY We consider a reservoir of porous medium of cross-sectional area A, extending from x = 0 to x = L. This reservoir contains, aside from the solid matrix itself, a gas phase and a "combined liquid phase" which is a combination of two immiscible liquid phases — namely, an oil phase and a water phase. The oil present in the reservoir is assumed to consist of three fractions, a noncondensable gas, a nondistillable residuum, and a vaporizable oil fraction which may be present in both the gas phase and liquid phase. Before the heat-wave process begins, preheating has taken place and has imparted an initial temperature distribution T,(x) to the reservoir. At the start of the process, a stream of oxygen-bearing gas is introduced through the face at x = 0. This gas supports the combustion of the residual fuel and supplies the heat throughout the process. In order to develop a tractable system of equations, the model properties are postulated as follows: (1) the system is isotropic and homogeneous; (2) there is a uniform fuel content throughout the reservoir; (3) combustion takes place in a moving vertical planar region of infinitesimal thickness; (4) the temperatures of the fluids and the solid matrix are identical; (5) radiation is negligible; (6) the gas and liquid saturations are uniform throughout the reservoir and remain unchanged

Jan 1, 1965

By Simon C. Dominy, Alwyn E. Annels, Mark A. Noppé

Abstract - Mineral Resources and their subsequent conversion to Ore Reserves are of key importance to mining companies. Their reliable estimation is critical to both the confidence in a feasibility study, and also to the day-to-day operation of a mine. Together with sampling, assaying, geological and other errors introduced during interpretation and estimation, additional errors are likely to be introduced during the application of technical and economic parameters used for conversion of resources to reserves. There is thus a requirement for high-quality interpretation and estimation to be supported by high-quality data. Any company expecting to make sound investment or operational decisions must base this on both relevant and reliable information. An Ore Reserve statement generally contains a single set of grade and tonnage figures without a discussion of the potential inherent errors in these estimates. Some sensitivity studies may be run, but confidence limits are rarely quoted and, if they are, often do not take into account many of the factors that cause uncertainty in the grade and tonnage estimates. Mineral Resource and Ore Reserve estimates thus carry certain errors leading to uncertainty and risk; some of these are unquantifiable for various reasons, for which the operator should be aware. This paper presents a review of the potential sources of error that might occur during a resource estimation program, which are carried through into the reserve estimate. A number of methods are discussed that allow the estimator to be more transparent about the inherent risks in his/her estimate. Emphasis is placed on data quality, and the requirement for strong quality management to be linked to continuous improvement.

Jan 1, 2002

By J. S. Fox

Major-element data for unaltered, unmineralized felsic host rocks from a number of stratigraphically simple, massive volcanogenic Zn-Cu(-Pb) sulphide deposits of low metamorphic grade have been compiled. The petrochemical affinities of these host rocks have been determined (by standard means and by discriminant analysis) and compared. This comparison indicates that volcanogenic deposits in felsic terrains are not restricted to the classical calc-alkaline rock association as previously thought, but can actually be hosted by rocks showing a range of iron content. There is a positive correlation between differentiation trend and are tenor. Zn-Cu ores usually have iron-rich felsic hosts (most Canadian Shield deposits); Pb-Zn -Cu ores have iron-poor felsic hosts (Japanese, Iberian and Tasmanian deposits). This parallels the antipathetic relationship between iron content and background lead levels evident in young, unmineralized, island arcs as well as in many older belts. Correlations between differentiation trend on one hand and massive ore mineralogy and the relative proportions of various rock type (including rhyolite, quartz-porphyry and coarse pyroclastic rocks) on the other are also evident. It is concluded that the recognition of a calc-alkaline differentiation trend cannot be used as a prospecting guide, as has previously been proposed. However, in view of the above correlations, the recognition of a given trend may aid in the formulation of an effective exploration philosophy.

Jan 1, 1979