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By R. H. Eric, P. Taskinen, A. Bhalla, P. Halli

Sustainable development requires less energy consumption with lower carbon footprint. In this review the solid state reduction behaviour of three oxide ores using methane gas are briefly summarized based on experimental work conducted in our laboratories. The discussion concentrates mainly on mechanisms of the reduction studied through SEM-EDAX and X-ray diffraction techniques. Limited preliminary kinetic input is also mentioned. Iron ore containing titanium and vanadium could be reduced significantly in the solid state with methane-hydrogen mixture up to 400 °C lower than is needed in ordinary solid state carbothermic process. The reduction of chromite and manganese ores were possible similarly at lower temperatures with potential energy savings lower carbon footprint.

Mar 1, 2017

By Ajoy Singh

A study was conducted to investigate the damage potential to underground multi-seam openings caused due to vibration generated by open-pit coal mine blasting. The objective was to recommend optimal explosives weight per delay to be detonated in open-pit blasts to ensure the safety and stability of underground openings. Sixteen blasts with varying charge weights and initiation sequences were conducted at Samleshawari open-pit mine and eighty four blast vibration data were recorded in the Hingir Rampur underground colliery in India. Analysis of vibration data showed that roof of the underground openings vibrated with higher amplitude of vibration compared to pillars and floors. The amplifications of vibration in the roof at the junction were upto 4.3 times the pillar vibration. It was observed that coal chips detached from roof when the peak particle velocity reached 131 mm/s or high. The vibration magnitude recorded was higher in upper seams openings than in below seam openings. Rapid attenuation of vibration was recorded in below-seam openings at similar locations. Appropriate particle-charge weight-distance equations were established to calculate the safe explosive weight per delay to be detonated in open-pit mine for safety of multi-seams workings of underground mine. The support for the galleries and junctions were further modified for the working seams to ensure greater safety.erground Coal Mine

Jan 1, 2012

By M I. Pownceby, S Bhargava, F Charalambous, S McMaster, R Ram, J Tardio

"A key component of any geometallurgical investigation involves being able to predict element or mineral recoveries from simplified input data such as bulk chemistry and/or mineralogy. This relies on the metallurgist having access to accurate information regarding the chemistry of the ore and gangue minerals as well as the likely impact on processing/extraction caused by the impurities (present either as gangue or as substitutional impurities). In this study the chemical properties of two commercially important uranium minerals, brannerite (U4+Ti2O6), and uraninite (U4+O2), were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). Significant levels of impurities were present in both samples with the uranium minerals deviating significantly from their ideal chemical formulae. Differences in chemistry were due to: cationic substitution decay of the uranium isotopes into radiogenic lead and other daughter products mixed uranium oxidation states post-depositional alteration.As well, the brannerite sample showed evidence of significant radiation-induced metamictisation. Leach tests to measure the ease of extraction of uranium from both samples were conducted over a wide range of conditions (temperature, acid concentration and oxidant concentration). For uraninite, the lower U dissolution rates observed in the natural sample compared to a synthetic UO2 sample were directly attributed to the presence of impurities. For brannerite, significant metamictisation of the natural sample led to enhanced U extraction rates compared to a heat treated fully crystalline sample. This study highlights the importance of detailed mineralogical characterisation studies in any uranium process mineralogy investigation as the compositional, textural and microstructural aspects of the main uranium phases present will likely play an important role in any process to extract uranium.CITATION:Ram, R, Charalambous, F, McMaster, S, Pownceby, M I, Tardio, J and Bhargava, S, 2013. Chemical and microstructural characterisation studies on naturally occurring uranium minerals - implications for processing, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 325-334 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By J. E. Gebhardt, B. Temel Mckenna, W. Lee, C. S. Macomber

X-ray diffraction (XRD) data was extracted from various sources to develop qualitative ternary and tetrahedral plots differentiating mineralogy, bond work index (BWi) and hardness of ore bodies at different mine sites. A large number of historic reports and compiled characterization laboratory data were used to create a searchable "data lake." The data lake provides a means to locate, consolidate, and visually represent XRD from disparate sources. Visualizations with large amounts of mineral ore XRD characterization data provide a qualitative assessment of ore properties, including comminution qualities such as material hardness. The visual map can be employed to quickly estimate expected ore character and behavior, given XRD analysis of samples from newly characterized and unfamiliar ore. Keywords: Mineralogy, Characterization, Comminution, Database, Ternary, Tetrahedral

Jan 1, 2020

Mining had a very considerable effect on the country's development. The visual evidence remaining is an integral part of New Zealand history. Early mining for manganese and copper in the 1840s was succeeded by alluvial gold rushes. These gave way to hard rock extraction, hydraulic elevation and dredging. Coal mining dating from the 1850s was fairly widespread. Other minerals were obtained on a small scale. Manufacture of mining machinery stimulated industrial engineering enterprises. Schools of mines played a significant part in advancing technical skills and several remain as museums. Surviving mine structures and site relics are part of the industrial heritage signifying the technological and economic development of a small isolated nation. Some of these are described. Identification, recording and preservation where practicable is advocated.

Jan 1, 1990

By J. D. Kalasky, Stephen Krickovic

A degasification experiment was conducted in a Pocahontas No. 3 coalbed mine in Virginia. It involved (1) drilling holes in the coalbed in the out- side headings of a set of five being developed in virgin area, and (2) conducting a methane emission rate study as mining progressed and additional holes were drilled. Degasification from all drill holes except the longest in each of the outside headings and the first three drilled (excluding the in-situ pressure hole), was erratic and inconsequential in methane emission rates. The two longest holes liberated 66 and 79 cfm of methane, which is significant for the coalbed, but such quantity lasted a relatively short time; the first three were uniform but low in methane emission.

Jan 1, 1972

By Jaime Tumialán de la Cruz

El presente texto busca describir las experiencias adquiridas en la mina de Cerro de Pasco a través del uso del "scooptram" eléctrico "LHD" de 2.2 yds. cú., marca "Jarvis Clark, a fin de mostrar su aplicación en otras minas cuyos problemas y características se asemejan a Cerro de Pasco. Los objetivos del empleo de este equipo son: aumentar la productividad en las áreas minadas por el método corte relleno descendente-mecanizado, mecanizar parte de la mina con equipos "LHD", pese a los problemas de ventilación, las temperaturas altas y reemplazar estos mismos equipos por aire acondicionado. En este sentido, se logró demostrar la eficacia del equipo eléctrico, especialmente en el uso de minas antiguas y de mayor profundidad, así como se mejoró las condiciones ambientales de trabajo y el costo de mantenimiento de los equipos eléctricos resultó más económico que las de diesels.

Nov 20, 1978

The knowledge of aggregate size under various chemical and hydrodynamic conditions is very important for selective agglomeration, flotation and water clarification processes. Traditionally, aggregate size measurements are conducted using an ex-situ technique or in a diluted suspension. In either case, the measurement occurs in an environment that does not resemble the actual conditions under which the aggregates are formed. In this study, an on-line scanning laser microscope has been used to study the coagula size of micronized coal suspensions as a function of pH, solids concentration and agitation intensity. A maximum aggregate size of 310 µ m was obtained under relatively quiescent conditions and at pH values near the iso-electric point (iep) of the coal. The aggregate size results compare well with the coagulation efficiency measurements obtained under the same pH conditions.

Jan 1, 1994

By J. R. J. Edwards

Jaspilite, a mineral consisting of silica and iron oxide in varying proportions, is one of the host rocks of the high grade ore deposits situated in the Middleback Range of South Australia. As a result of laboratory investigations, a flowsheet was postulated for the beneficiation of jaspilite to produce an acceptable grade product for feeding to blast furnaces, The flowsheet involved the reduction of the hematite in the haspilite to magnetite, the grinding of the reduced product to 95 pct minus 325 mesh Tyler followed by wet magnetic separation, hydroseparation and filtration to yield a magnetite concentrate. Agglomeration of the fine concentrate would then be necessary to meet the physical requirements of blast furnace feed. To prove the postulated flowsheet, to obtain a more accurate estimate of costs and to obtain design data for a commercial installation, a pilot plant was constructed at Whyalla, South Australia.

Jan 1, 1960

By R. D. Irwin, W. M. Mullins, E. A. Medina

"Various stability criteria are introduced and thermo-kinetic models for metallurgical processes are used as concrete examples for evaluation. Kinetic criteria for the process of dynamic recrystallization are proposed. These criteria are compared to the non-equilibrium thermodynamic approaches discussed in the literature. The application of macroscopic stability criteria to materials processing is then discussed.IntroductionThe mechanical behavior of metals at elevated temperature is very well predicted by any of several empirical constitutive relations. Typical is the power-law (or Swift's) form,Equationwhere r-is the stress, y is the strain and m, n , t0, y0 and Q are material constants. This form has been used with some success in the metals processing area [1]. In general, though, all of the empirical constitutive equations are static, failing to account for any dynamical properties of the system they seek to describe.The physics of warm deformation is qualitatively well understood. An example is power-law creep, where the dominant mechanism is assumed to be lattice diffusion limited climb of dislocations, which allows the strain-rate to be determined by the applied stress through"

Jan 1, 1997

By R. A. Jankowski

Although the number of operating longwall mining systems has remained relatively consistent over the past five years, longwall production levels have increased significantly during this period. Longwall production currently accounts for approximately 50% of U.S. underground coal production. While longwalls are highly productive and offer other advantages, operations employing this method of mining continue to experience dust compliance problems. This increased longwall productivity has meant that far more dust is being produced. An improved understanding of the longwall face ventilation system and advancement of face ventilation technologies are necessary to ensure all face personnel are allowed to work in an environment that is free of excessive levels of airborne respirable coal mine dust. The Dust and Toxic Substances Control Branch of the National Institute for Occupational Safety and Health's Pittsburgh Research Laboratory has examined several basic principles of the longwall face ventilation system, and has evaluated the effectiveness of numerous improved face ventilation techniques for longwall mining systems. These include identifying improved techniques for measuring face ventilation parameters on longwall mining sections and investigating the fundamental relationship between face air flow and the entrainment and dilution of respirable coal mine dust. Studies have been completed to determine the impact on face dust levels from using belt entry air to ventilate the longwall. Novel methods have been identified to increase the amount of face air flow and to manage face air flow to most effectively minimize face workers' dust exposure. Unique systems of auxiliary face ventilation have been developed and evaluated at full-scale, simulated longwall test facilities. The theoretical and applied aspects of each of these principles and technologies are discussed. Application of these results, throughout the longwall mining industry, as documented from surveys conducted in the early 1980's and 1990's, have reduced the health hazard associated with excessive exposure to respirable coal mine dust.

Jan 1, 1998

By Viswanadham B. V. S., Babu K. V

Many refineries are in the process of revamping and expanding their existing facilities. Most of the refineries are located in coastal areas due to ease of transportation and storage of crude oil. Considering the criticality of structures as well as prevailing soil conditions, most of the structures are supported on pile foundations. In depth review of sub-surface investigations data followed by liquefaction assessment of the site, it is noticed that site is prone to liquefaction during the seismic event. Among various techniques, driven cast-in-situ piles were selected to mitigate liquefaction. Static cone penetration tests were conducted during the pre and post installation of driven cast-in-situ piles at identified locations. Analysis of cone penetration test data shows that considerable ground improvement has been achieved post-installation of driven cast-in-situ piles.

Sep 1, 2022

By Stanford O. Grodd

The Sanford Lake district encompasses an area covering 24 square miles in the central Adirondack Mountains of northern New York State. Discovery of the titaniferous magnetite deposits dates back to 1826. Several attempts to exploit the ores for iron prior to 1942 proved uneconomical because of difficulties with the associated titanium, lack of transportation facilities, and the isolated location. Since 1942, the National Lead Company has produced ilmenite concentrates for the titanium pigment industry, and a magnetite by-product used in the steel and refractory industries. Rocks of the area are Precambrian in age and of igneous origin. The area has a history of erosion, deformation, and metamorphism, subsidence, and finally uplift and glaciation. The resulting topography is extremely rough with drainage patterns controlled by a combination of fault patterns and glacial modifications. The district is within the large anorthosite massif making up the central high peak area of the Adirondacks. All of the various lowsilica rock types associated with the massif are found within the boundaries of the district. These consist of both the Marcy and Whiteface types of anorthosite and of gabbroic anorthosite, gabbro, and different grades of titaniferous magnetite ores. All of the rocks contain the same minerals and differ only in their percentages of these consitituents. Gabbro, and ore associated with it, demonstrate flow structure as both have foliation and lineation. Anorthosite and its associated ores are massive and show very little primary structure. Minor pegmatites and diabase dikes provide evidence of remobilization in selected areas and of late intrusion as well. Faulting is prevalent and follows a regional pattern of major faults trending northeastsouthwest and of minor faults at nearly right angles to them. There are four mineralized areas where an economic grade of ore has been found. Three of these have both gabbroic-type ore and anorthositic-type ore. The fourth has only gabbroic ore. Ores are graded according to their TiO, content, and these range from 9.5 per cent to over 30.0 per cent TiO,. Ore bodies of both types are related to gabbro and conform to the configuration of the gabbro bodies within the anorthosite. At least three distinct theories of ore genesis have been expounded by different investigators. Others propose some variations of one or more of these. Although complete agreement probably never will be reached, it is certain that no one process of ore emplacement can explain the complicated picture as seen today. Further understanding of the ores and their origin will require detailed mapping, sampling, and mineralogical studies of the entire district, and then it may never be understood without qualification.

Jan 1, 1968

By A. G. Storey, J. B. W. Bailey

"The Noranda Process at the Horne Division ofNoranda Mines Limited now smelts approximately 350,000 short dry tons of concentrate a year, which is 40% of the total smelter throughput. Campaigns are averaging 200 days and refractory consumption is much lower than in the conventional smelter.In this paper, details ofrecent operation are given, together with updated projections for operation with higher levels of oxygen enrichment.IntroductionThe Noranda continuous smelting process has been in operation at Noranda, Quebec, for six years and in that time it has smelted a million and a half tons of concentrate. It is currently smelting 1,200 to 1,250 tons per day of concentrate on an instantaneous basis"" and it is handling approximately 40% of the Horne smelter throughput.This paper will describe the current operation of the process and the improvements that have been made since 1976, when the process was described by L.A. Mills et al.lSince early in 1975, a high-grade matte averaging 73% copper has been produced, which is then sent to the converter aisle for final treatment. All the information in this paper refers to the operation of the process in the matte mode .Early in 1978, Kennecott Copper Corporation started up their new smelter near Salt Lake City, Utah , which has three Noranda Process reactors operating with high oxygen enrichment of the tuyere air (2). These furnace s incorporate some design improvements, which will be described briefly."

Jan 1, 1980

By Jorge Da Silva

El presente trabajo señala la importancia de la función del área de Tecnologías de la Información en el logro de los objetivos de la empresa minera Yanacocha a través de un programa de excelencia operacional, donde se optimiza y distribuye de mejor manera los recursos de la empresa, se explora nuevas áreas, se legaliza los permisos correspondientes para acceder a nuevas tierras y se compromete a los trabajadores con los objetivos de la corporación.

Sep 9, 2007

By Siddhartha Roy, Hemant Agrawal, Ram Madhab Bhattacharjee, Devi Prasad Mishra

The paper addresses heat stress in underground coal mines, which poses significant threats to miners’ health, safety, and productivity. It involves a comprehensive ventilation survey in three deep and mechanized underground coal mines in India. Using VentSim software, 3D simulation models were developed to predict heat stress conditions and explore the application of auxiliary ventilation and spot coolers to reduce heat stress.

Oct 1, 2023

Physical model testing at Bergbauforschung is done in two rigs, a roadway rig and a longwall rig. The loading of such models, in scale relation to the con- ditions in the collieries provides valuable guidance to the probability and nature of failures, and thus to support requirements, in structural, roofbolts and self- auvancing supports. The success of such modelling when related to subsequent underground designs put to use suggests that such methods of investigation could be extended to pillar extraction problems also.

Jan 1, 1974

By Frank Rausche, Scott D. Webster, Rozbeh B. Moghaddam

"Pile foundation driveability is a function of several variables such as subsurface characteristics, hammer type, hammer efficiency, pile type, and plugging conditions. One important phenomenon occurring during pile driving, and yet not well documented and published, is the friction fatigue, where a reduction of shaft resistance is observed as the pile is driven to greater embedment. This paper introduces current soil models developed for the assessment of friction fatigue, and further presents a comparison between predicted driveability obtained from Wave Equation Analysis Program (GRLWEAP) and field driving records. From a literature survey, and review of technical articles, a widely-used soil model known as AH-01 has been selected to analyze the friction fatigue concept. Using a WEAP software, two driveability analysis were completed using the standard approach with setup factors, and adapting the AH-01 model into the WEAP input file. Driveability predictions were compared to the driving records corresponding to a 1676-mm x 44- mm open-ended pipe pile with a total and embedment lengths of 180-m and 119-m, respectively. Results from analyses and the comparison presented in this paper provide further information regarding existing methods for the incorporation of the friction fatigue concept to the driveability analyses, and contributes to a better prediction of driveability of open-ended pipe piles. IntroductionDynamic measurements during pile installation provide more dependable information as compared to results obtained from predictive models used for design. Despite uncertainties associated with a specific project site and foundation type, measured data provides a reliable understanding of the soil resistance and its distribution throughout the length of the pile. Back-calculations or back-analyses based on a series of measured data from a pile driving process could help to obtain reliable models to better predict events related to pile installation process in spite of all variability related to fitted models. One of the widely-used analysis regarding pile driving during the design phase is the “driveability analysis” where capacity, blowcounts, maximum stresses in the pile element, and transferred energy from the hammer to the pile element are predicted using mathematical models along with a software. Such analysis requires relevant information regarding soil, pile, and hammer properties combined with a deep understanding of the level of impact each one of these properties could have on the analysis."

Jan 1, 2017

By L Sandery, S Light

Within 22 months of commencing decline development, the Prominent Hill Ankata Underground Project achieved its full production rate of 1.2 Mt/a.In 2010 construction of the Ankata Underground Project was approved. Decline development commenced in November 2010 and the turnout for the first sublevel was reached by August 2011. The first stoping ore was produced in the first quarter of 2012 and production was successfully ramped up to full production during the third quarter of 2012.Diamond drilling commenced in October 2011 and was conducted concurrently with the underground development. This presented challenges as mining and production targets had to be balanced with underground exploration activities. To achieve production on schedule, without adversely affecting the diamond drilling program and future development, meticulous and adaptive planning techniques were required. This included involvement from engineers, geologists, underground operators and underground diamond drillers.The granularity of these planning techniques allowed the management and prioritisation of development and diamond drilling down to an almost hourly basis. A constant flow of information from drill assay results was fed back into the planning systems. This resulted in a constantly evolving mine plan as the orebody was further refined. High priority areas were identified and targeted to allow continued development and a successful rapid ramp up to full production.CITATION:Sandery, L and Light, S, 2014. Managing the diamond drilling interactions in commissioning the Ankata underground mine, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 75–80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By H. Kato, G. Asai, R. Blickensderfer, R. Siemens

Some relationships were established among crystallographic orientation , rollability , deformation texture , annealing behavior , slip planes , and ductile- brittle bend transition temperature of molybdenum single crystals . Six large molybdenum single crystals obtained from an ingot melted by electron beam were oriented by X - ray diffraction and rolled on crystallographic planes of low indices in a known direction . During room temperature rolling , cleavage occurred on 100 type planes . At 300 ° C the crystals were rolled to 95- percent reduction in thickness . The crystals ( 001 ) [ 110 ] and ( 011 ) [ 100 ] were most easily rolled . Pole figures were used to correlate the deformation textures of the rolled crystals with the initial crystallographic orientation . Several of the textures which developed could be explained as a rotation about a < 110 > axis of symmetry . The cube crystal ( 001 ) [ 100 ] retained much of its " cubic " orientation . The (001 ) [ 110 ] crystal developed the simplest texture , whereas the ( 211 ) [ 113 ] and ( 211 ) [ 120 ] crystals developed the most complex textures . The 1 - hour recrystallization temperature of the crystal ( 211 ) [ 113 ] was 700 ° C , which is about 300 ° C lower than that of commercial polycrystalline molybdenum . The poles of the slip planes ( as determined from gross slip lines at relatively low magnification ) tended to lie within 20 to 60 degrees of the pole of the rolling plane . The Knoop hardness was slightly dependent upon crystallographic orientation but more dependent upon rolling direction . The ductile- brittle bend transition temperature was dependent upon the rolling orientation and the dislocation density .

Jan 1, 1964