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By B. Elevli

The aim of this paper is to demonstrate the implementation of multicriteria analysis in selection of the most suitable underground ore transport system for a chromite mine in Turkey. The related problem includes five possible ore transport systems and six criteria to evaluate them. The adopted evaluation and ranking method for this study is PROMETHEE. PROMETHEE I revealed a partial order of alternatives where incomparability exists. PROMETHEE II gave the absolute ordering of alternatives. The results have shown that the PROMETHEE method can be successfully used in solving mining engineering problems. Keywords: multi-objective, decision analysis, mining, ore transport system

Jan 1, 2004

By C. L. Schneider, R. P. King

The ability to predict the liberation spectra that will be produced by a closed-continuous grinding circuit is of fundamental importance for the design, optimization and control of most operations in an ore dressing plant. The only known approach through which such a calculation can be performed is the population-balance-model equation. The latest, and certainly most significant, advance made in this area is the solution proposed by King (1990), which requires one textural parameter measured directly from the ore being studied. The main advantage of King's solution is that, unlike the conventional solutions, it does not require the estimation of hundreds of arbitrary parameters that cannot be independently measured. However, King's solution relies heavily on a knowledge of the detailed internal structure of the Andrews-Mika diagram (Andrews and Mika, 1975), which has never been measured for any ore. The characterization of the internal structure if the Andrews-Mika diagram requires the measurement of the liberation spectra at several progeny sizes produced by the breakage of monosize-monograde particles at several different grades. In this paper, a procedure based on magnetic fluid fractionation for generating seven narrow-size, narrow-grade samples is presented. Each of these samples was then broken into six progeny size classes in an ultrasonic mill. The one- dimensional liberation spectra of each of the 42 progeny and seven parent particle samples were then measured by image analysis. The measured linear-grade distributions are presented in this paper. The calculation of the correspondent volumetric-grade distributions is discussed.

Jan 1, 1995

By K. V. S. Sastry, S. C. Panigraphy, D. W. Fuerstenau

The batch balling behavior of hematite, magnetite and limestone was found to depend markedly on the grinding method used for feed preparation. Wet ground materials require higher moisture for balling than do dry ground materials. Further, as the fineness of the wet-ground material is increased, the overall rate of agglomeration decreases, whereas the opposite is true for dry-ground materials. In contrast, the resulting pellet size distributions are not affected by the nature of the feed material preparation. These differences and similarities in the agglomeration behavior between wet and dry ground materials may result from the hydrophilic/hydrophobic nature of the surfaces, the formation of pre-agglomerates during dry comminution, and possible variations in the packing density of particles in the agglomerates.

Jan 1, 1978

By R. A. Hodge, J. W. Murray

By an order of the Executive Council of the Provincial Government dated January 18, 1979, a Royal Commission was established under the Public Inquiries Act to: 1) Examine the adequacy of existing Federal and Provincial requirements for the protection of the health and safety of workers associated with exploration, mining and milling of uranium in B.C. and for the protection of the environment and of the public. 2) Receive public input on these matters. 3) Make recommendations for setting and maintaining standards for worker and public safety and for the protection of the environment as a result of the exploration for the mining and milling of uranium ores. At that time,and at the present time in British Columbia, no uranium mines were, or are, in operation. Exploration at a number of sites was under way and one deposit, the Blizzard deposit, with estimated reserves of 1.92 million tonnes containing approximately 4.74 million kilograms of U308 was at an advanced stage of exploration. With our Terms of Reference, and because of the diverse geology of the western Cordillera which could potentially host a broad variety of uranium, deposit types, the Commission was faced with the task of considering environmental and health protection necessary for the potential development of [any] kind of uranium mineralogy situated in [any] of the environments found in British Columbia. Over the past 17 months since that time, much has transpired, culminating in the February 27, 1980 Provincial Government announcement of a seven year moratorium on exploration, mining and processing of uranium coupled with the termination of our Inquiry before completion of the hearings. The Government sebsequently modified its decision to terminate the Commission completely, deciding instead to stop the hearing but allow time for the Commission to gather in the work that had been initiated

Jan 1, 1980

Al2O3,-WC Composite powder for cutting tools was synthesized by self-propagating high-temperature synthesis using A1 powder as a reducing agent. WC, W2C and Al2O3 were concurrently formed in WO3Al-C system. It was found that the complete reaction was achieved with excessive addition of carbon and appropriate processing parameters such as degree of dilution, particle size of aluminum, compaction pressures of green pellets and carbon source. The final product which was leached by 50% HN03+HF diluted solution was consisted of Al2O3-55wt% WC having 2-3um of mean particle size.

Jan 1, 1999

By C. Menidiatis

The first cement plant of TITAN Cement Co was founded in Elefsis in 1902. It was the first cement industrial facility to operate in the Balkans and in the Eastern Mediterranean region. Currently have four cement plants in Greece producing 5.4 million tons per annum, and 25 ready-mixed concrete sites producing 1.4 million m3 annually. It has a total of 20 quarries, 14 of which are producing materials used in the making of cement while the remaining six produce aggregates used in the production of ready-mixed concrete. All plants in Greece are accredited for ISO 14001. The restoration of quarries began in 1976 at the company?s limestone quarry of the Patras plant, and was soon extended to all quarries. At that time, a department responsible for all environmental issues was established. To date, over 700.000 shrubs and trees have been planted and maintained at quarries, plants and ready-mixed concrete facilities, while over 100,000 trees have been donated to municipalities, communities, customers and to the Greek state.

Jan 1, 2002

By Jorge Castillo

El presente texto señala el uso del polímero denominado quitosan para el proceso de floculaciòn de pulpas minerales. Dicho biopolímero es un derivado de la quitina proveniente del caparazón de langostinos, el cual es desechado por la industria langostinera peruana. El estudio, se realizó con pulpas de mineral del tipo sulfurado que van desde los 20 hasta los 36 % de sólidos, donde los mejores resultados de floculación se obtuvieron en medio cercanos al neutro y con una concentración de 0,2 % de quitosan y 0,2 % de ácido clorhídrico. En consecuencia, el biopolímero con un floculante industrial produce velocidades similares de sedimentación y menor altura de lodos en la zona de compactación.

Sep 12, 2011

By William R. Webster

This is a subject which our Institute has made peculiarly its own. In the first volume of its Transactions the analysis of steel received attention, and every subsequent volume has borne witness to the acuteness and industry of our members in the investigation of this subject. The keynote mas struck, in this as in so many other lines of progress, by A. L. Holley, in his paper on " Tests of Steel," read at the Easton meeting of October, 1873 (Trans., ii., 116)—an essay which may rank as a classic by reason of .its elegant form, logical force, and clear prevision of all the bearings of its theme, Taken together with the brief report of the discussion which followed it (in which Dr. Drown emphasized the effects of heat-treatment and mechanical handling, and Dr. Sterry Hunt the importance of minute variations in chemical composition, and of possible isomeric and allotropic conditions), it constitutes, after the lapse of twenty-five years, an admirable and adequate introduction to the long list of technical papers which have succeeded it. Three years later came the epoch-making papers of Dr. C. B. Dudley on the relation between the chemical composition and physical properties of steel rails, which, with the voluminous discussion they evoked, constitute a special volume, published by the Institute, and full of useful suggestions. If Dr. Dudley could be induced to resume this investigation, he would doubtless be able to solve many points still uncertain or disputed. But I cannot undertake to review the history of this subject, as represented in our Transactions—still less to restate all the contributions to it which have been made in books or in papers before other technical societies, since the initiative was taken by the Institute. My more modest purpose is to indi-

Jan 1, 1899

By Stephen R. Brown

Current conditions in the copper market demand that mine and plant operators make budgeted production targets at the lowest possible unit costs. For those companies bringing new production capacity on-line, achieving budgeted production levels as quickly as possible after start-up is vitally important to minimize unit costs and to begin a positive cash flow. Whether the objective is to simply improve unit costs or successfully start-up a new, complex plant, success will be strongly influenced by .the skill levels of the operators :and supervisors. The only way to assure return on plant investment, and to survive during depressed metal prices, is to ensure that plant operators have the knowledge to effectively run the plant. Technology available in computer-based, multimedia training systems, including: interactive animation, videos, voice-overs, schematics, and text can now be used to train operators at their own pace using plant-specific information. Additionally, it has been shown that learning through multimedia provides a higher degree of long term retention than more traditional learning methods.

Jan 1, 1999

By R. C. Mahon

The Homer iron-ore mine is at Iron River, Mich. Because it covers a large area, 400 acres, and because there was a considerable depth of water in the glacial drift above most of the ore bodies, this mine has presented a number of unusual and often difficult operational problems. The purpose of this paper is to discuss a few of the most important problems encountered. Surface Water Mining on this property was started on one 40-acre tract. The ledge in this area was the highest on the property and, although it was a real problem, water could be handled by underground pumping. During the first period of mining, drifts were driven just under the ledge and holes were drilled through to the surface material. In later years these drifts have been extended wherever possible. Although these drifts assisted in the drainage problem, it was evident they would not be sufficient alone. Before mining on a large scale could be started on this property, the water problem had to be solved. A number of test holes were put down to the ledge, and showed that there was an average 150 ft. of water-saturated glacial drift above the ledge over the rest of the mine. The upper 70 ft. was gravel and sand and the lower 80 ft. clay and hard pan, with some narrow seams of sand and gravel. It was evident that the water above the clay seam could not be drained off through openings in the ledge and for that reason it was decided to install surface drainage wells. This method of drainage was entirely new at that time and was pioneered at the Homer mine. The sinking of the first well was started in June 1929. Immediately following the first well a number of wells were sunk, but only to the top of the clay seam. This was done with the idea that a greater capacity could be obtained in a shorter time from gravel seams where the water flowed more freely and that the cost of pumping the water above the clay seam would be considerably less than if the wells had all been sunk to the ledge at once. Before the drainage of surface water was started, 1200 gal. per min. against a head of 800 ft. was being pumped from the mine. By March of 1932, with five surface wells in operation, the mine pumping had been reduced to 150 gal. per min. At this time we were pumping 5000 gal. per min., under an average head of 110 ft. from the surface wells. The total pumping costs were 30 per cent less than in 1929 because the greater capacity was being pumped at a much lower head. From 1932 to 1936 the mine was idle and all surface pumping was stopped. Since 1936, 10 new wells have been added with a total pumping capacity of 8000 gal. per min. at the present time. The water level has been lowered 70 ft. since surface pumping was started in 1929, and it is now approximately at the top of the clay. To remove the water below the clay seam, 11 of the 15 wells were sunk to the ledge.

Jan 1, 1946

By K. Fukushima, K. Baba, H. Kurokawa, M. Yamagiwa

"The Toyo smelter has expanded its anode production capacity from 126,500 to 239,000 t/year by introducing technical oxygen into blast air for flash and converter furnaces and improving smelting facilities. Significant efforts were made in the expansion not to increase the number of workers, which mean development of some automation systems for the copper converters and anode casting wheel. The efforts have resulted in the above-mentioned increase in productivity and a saving of production cost as well as a decrease in the number of workers for the anode casting operation.IntroductionThe Toyo smelter has been performing a highly stable and pollution free operation since its commencement in 1971 (1). Its distinctive features are the on-line control by process computer (2) and the high productivity without trouble. But owing to the so-called oil crisis in 1979, we were faced with a sharp increase in production cost. To decrease the production cost, some measures for saving of energy were planned and carried out, such as conversion from oil to coal in a flash furnace (3), the heat recovery from converter slag and the introduction of technical oxygen in blast air with the intention of energy saving as much as possible.The first increase in production capacity and some savings of production cost were attained in 1982 by the introduction of technical oxygen in blast air for the flash furnace without major modification of the furnace as shown in Table I. The capacity of an oxygen plant is 7,800 Nm3/H as 90% O2 . Part of oxygen from the plant is also supplied to tuyeres of copper converters through an oxygen holding tank with a volume of 830 m3 at 7 kg/cm2-G."

Jan 1, 1989

By N. R. Andrade-Gonzalez

In this paper, the effect of magnesium and strontium additions on the heat treatment behaviour of cast A319,2 alloy was investigated, Permanent mold samples were heat treated at 495 °C for 4 and 24 h, then quenched in hot water and aged at 180 °C and 220 °C for different temperatures, It is found that multiple aging peaks are present in the age-hardening curves of Al-Si-Cu alloys, mainly when Mg and Mg-Sr are added, The results of electron probe microanalysis (EPMA) observations reveal that the age-hardening behaviour is related to the precipitation sequence of alloys, For the Al-Si-Cu alloy, the first aging peak is the result of the high-density GP zones, while the subsequent peaks arise from metastable phases, Obvious intervals during the transition from GP zones to metastable phases may be the main reason of the formation of multiple aging peaks, It is seen that addition of Mg (-0,40 wt %) leads to the precipitation of coarse Al5Mg8SioCu2 particles. When modifying the high Mg alloys, Cu-intermetallics segregate in areas away from the growing Al-Si eutectic regions, Modification with strontium retards the precipitation of the silicon out of the matrix.

Jan 1, 2005

By S Long, A J Koen, D MacKay

The Mt Wright Underground Mine is located near the town of Ravenswood in North Queensland and is operated by Carpentaria Gold – a wholly owned subsidiary of Resolute Mining Limited. Following the evolution of the mine plan through a number of stages, the ‘sublevel shrinkage (SLS) with continuous fill’ mining method was implemented in 2010 to extract the Mt Wright orebody. The production front in this mining method is similar to a sublevel cave (SLC) operation; however, backfill is placed into the top of the production zone as opposed to requiring the overlying strata to cave.Continuous fill to replace the void created by extracting the ore was required to manage the potential risks associated with the proximity of infrastructure to the footwall, associated long-term stability and air blast potential due to the limited ‘cavability’ of the material within the cave zone. The available fill material was sourced from a disused waste dump from a previous open pit operation, which introduced further technical and economic risks associated with dilution from ‘no grade’ broken material. Procedures and processes to manage these risks have been incorporated into the operation of the mine.Despite encountering a number of challenges, the SLS method has been in use for approximately three years at Mt Wright and has proven to be viable economically, technically and operationally. This paper will discuss the challenges encountered and what was done to overcome them, the operational and financial performance to date, along with the outcomes of some successful continuous improvement projects that have improved the efficiency of the operation.CITATION:Mackay, D, Long, S and Koen, A J, 2014. Sublevel shrinkage – the Mt Wright story, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 205–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By Jan Boon

Las compañías de exploración junior realizan actividades de exploración que pueden establecer eventualmente una mina. En ese sentido, el presente texto señala la aplicación del modelo dominante RSC (Asociación de exploradores y desarrolladores de Canadá) en la calidad de las relaciones de la comunidad minera y los empresarios. Es decir, se muestra el poder explicativo de la herramienta de caracterización de relaciones empleada en un marco interaccionista y que puede ser aplicada de manera inclusiva en el campo de la RSC.

Sep 1, 2013

By Roger Storry, Donald Bruce, Arnaud Hochart

"INTRODUCTIONThe Port of Miami Tunnel (POMT), designed and constructed by Bouygues Civil Works Florida between 2009 and 2014, was a Public Private Partnership between the Miami Access Tunnel Concessionaire, Florida Department of Transport, Miami-Dade County and the City of Miami. The project comprises dual 11.3m internal diameter, 1.27km long, twin lane road tunnels running between Watson and Dodge islands and under the main shipping channel in Biscayne Bay (Figure 1).The POMT was a unique project which embodied many technical firsts and involved the first large diameter tunnels constructed through Florida’s challenging sedimentary carbonate strata. At the outset, a comprehensive ground investigation was performed, using both conventional and less conventional investigation techniques, to characterise the highly heterogeneous ground conditions.The findings of the investigation had a major impact on the tunnelling methods, triggering a series of mitigation works to ensure that the tunnels could be excavated safely and effectively. The mitigations included modifications to the already designed Tunnel Boring Machine (TBM), to facilitate an innovative excavation process, and a unique grouting campaign (Storry et. al. 2013a). The project was completed and opened to traffic in August, 2014 and has significantly alleviated traffic congestion in Downtown Miami.GEOLOGICAL CONTEXTThe geological conditions at the project site consist of carbonate sediments which can be divided into distinct geologic units; the Miami Limestone Formation (Layers S3, S4), the Fort Thompson Formation (Layer S5), the Anastasia Formation (Layer S6), the Key Largo Formation (Layer S7) and the Tamiami Formation (Layer S8). Multiple changes in sea level over a relatively short geologic time scale have resulted in a heterogeneous profile consisting of interbedded sedimentary rocks and sediments, which vary widely, both vertically and laterally (Figure 2)."

Jan 1, 2016

By S. K. Tarby, W. O. Philbrook

The rate of FeO and MnO reduction from silicate and aluminate slags by carbon-saturated iron is dependent on both slag composition and temperature. Owing to variable stirring rules during- the course of reaction, the reduction processes occur in two stages in stationary graphite crucibles. In the first stage the slirring caused by CO evolution results in forced convection conditions in the slag. As the boiling action subsides during reduction, the flow conditions within the system become those defined by natural convection. Analysis of the data by an unsteady-state penetration model indicates that the rate of reduction is controlled by the rate of cocur-rent flow of' cations and anions from the bulk slag to the interface during both stages of reduction. The hearth reactions of the blast furnace have been extensively investigated from the viewpoint of equilibrium by deductions from controlled laboratory experiments. However, the literature contains relatively few studies that have been directed toward the area of slag-metal reaction kinetics, and the majority of these have been concerned with the rate and mechanism of sulfur transfer between iron and slag. More recently, attention has turned to the kinetic factors in the reduction of oxides from liquid slags. One of the first investigations in this field was conducted by Dancy1 on the reduction of pure liquid FeO and pure liquid Fe3O4 by carbon-saturated iron. The integrated form of the rate equation indicated that the reduction of FeO was of the first order up to 80 pct reduction. Over the initial 30 pct of reduction, the magnetite reaction was also interpreted as a first-order process. The rates of reaction were extremely rapid as indicated by a 30 pct reduction of the liquid magnetite in a time interval of about 1 to 2 sec. Phil-brook and irkbbride' studied the reduction of FeO from a lime-alumina-silica slag by carbon-saturated iron and solid graphite in stationary crucible assemblies. With the use of the differential form of the rate equation, the rate of the reduction reaction was found to be proportional to the second power of the concentration of the reactant FeO for both the slag-metal and slag-graphite reactions. These authors presented a number of comments in an effort to explain the difference between the molecularity of the above reaction and the observed second-order relation. One such argument, recently extended by Wagner,3 was that the rate-limiting step may well be one of transport control. A complete discussion of the proposed mass-transport control mechanism of this reduction reaction will be presented in a later section of this paper. Kinetic studies of the reduction of other oxide species, namely chromous oxide, titania, and silica, have also been reported. McCoy and philbrook4 used rotating crucible assemblies to investigate chromium reduction from Ca0-SiO2-A12O3 slags. First-order kinetic law was obeyed for the slag-metal reduction reaction as determined by the integration method of data analysis. Due to scatter of the data, any dependence of the rate constant on temperature or slag composition was obscured. Concentration-time data for the reduction of titania from blast-furnace type slags under reducing conditions were obtained by Delve, Meyer, and Lander.' The data were too few, however, for a formal kinetic interpretation. Kinetic data for the very slow reaction of silica reduction have been observed by McCoy and Philbrook6 and Fulton and chipman.7 The former experimenters found the reaction-rate constant for silica reduction by carbon-saturated iron to be 20 to 60 times less than the rate constant for chromium reduction. In their work on the reduction of SiO2 in mechanically stirred systems, Fulton and Chipman also found small values for the specific reaction rate and derived a high value for the energy of activation for the reaction. In both of these investigations, the reduction process was assumed to follow first-order behavior. schuhmann8 proposed that the rate-limiting step in this reaction is the diffusion of oxygen from the interface through a boundary-layer film to the bulk metal phase, and Rawling and Elliott9 have reported experimental confirmation of this hypothesis for temperatures below 1600°C. Turkdogan et a1.10 have also concluded that the rate of reduction of silica is a slow process and controlled by the diffusion of oxygen in the metal, but only in the absence of carbon monoxide bubbles at the slag-metal interface. In the presence of bubbles, achieved either by injecting carbon monoxide at the slag-metal interface or by blowing it through the metal and slag, these investigators found a rather rapid reduction of silica which appeared to be controlled by an interfacial reaction involving the de-sorption of silicate ions from the slag-metal interface to the metal phase as silicon and oxygen atoms. In view of the unresolved nature of the kinetics of FeO reduction and the lack of kinetic data for the manganese reaction,

Jan 1, 1968

By Ketelaar P. B, Nichols S, Power W. L, Utley D. C

The impact computers are having in geoscience is distinctly mixed. In the petroleum industry where much of the data are based on geophysics, computers have become an integral part of exploration and reservoir evaluation and simulation. In the minerals industry, the trend to computerisation is more advanced in some disciplines than others. Geophysical and remote sensing data are routinely processed and imaged using state of the art computer techniques. Mine surveying, planning, design and resource and ore reserve estimation are now all predominantly reliant on computers. However senior management of many companies, particularly in the mineral exploration industry, are still reticent to fully embrace the technology. 3D computer modelling of geology and orebody delineation is still largely in its infancy. Two current and significant drawbacks to the routine use of computer modelling of geology in both mining and exploration are the tedious and time consuming modelling process and the lack of seamless interaction between 3D computer-aided drafting (CAD) software and geographical information systems (GIS) which are largely 2D in their data treatment. There is an urgent need for a 3D spatial information system (eg 3D GIS) with intelligent and rapid modelling functionality. One of the keys to the successful building of 3D geological computer models begins with data base structure and design to ensure that there is no loss of data fidelity through data capture, storage, manipulation and modelling. Once a model is constructed, the latest generations of visualisation software provide sophisticated environments over a range of hardware platforms for visualisation in both mono and stereo viewing. This is demonstrated by the geological models which are presented in the digital interactive version of this talk whose URL on the World Wide Web is: http://www.ned.dem.csiro.au/FRACTAL/pubs/talk97AUSIMM/

Jan 1, 1997

By Fred Turin, Kim Cornelius, Lisa Steiner

NIOSH researchers have been examining underground coal mining activities in order to evaluate work crew hazards. In 1994 a continuous mining machine operator was killed by falling roof during extended cut mining. Many aspects of the incident were used by NIOSH researchers to develop a scenario interview. The goal was to provide a realistic framework for acquiring frank and detailed insights. The interview consists of two sections. The first describes the underground mining conditions. The second recounts the fatal incident. Each section is supplemented by a diagram and a set of questions addressing relevant safety issues. The interview was administered at three mines that actively take extended cuts. Researchers found the scenario approach to be an effective interview tool as well as an effective hazard awareness and safe work practices training platform.

When Haematite Explorations Pty. Ltd. began prospecting for petroleum in 1960, there was only ill-defined geological evidence on the land bordering Bass Strait to support the belief that petroleum lay trapped in sedimentary formations beneath its shallow waters.A reconnaissance of the area, made in 1961 by the airborne magnetometer method, covered the waters and islands of the Strait and overlapped the Victorian and Tasmanian coasts. The survey indicated the presence of the Bass Basin (which is completely water-covered), assisted in outlining the Otway and Gippsland Basins, and showed that each basin contains sedimentary rocks over 10,000 ft thick. Information on the regional geology and minor volcanic activity was also obtained.Marine seismic surveys carried out from 1962 to 1965 defined these basins more accurately and showed the nature and structure of the thick sedimentary sections.Correlation of the seismic data with onshore wells identified the sediments as Tertiary and Mesozoic. Subdivisions of the former in all basins and the latter in the Otway Basin were made. These Tertiary and Mesozoic rocks are not seriously deformed and they have good prospects of containing petroleum.Possible structural and stratigraphic traps, recognized from the seismic record sections by petroleum geologists, are being tested by offshore drilling which began in 1964.

Jan 1, 1966

The performance of two large-capacity ventilation systems was compared through tests conducted in a large dead-end heading at a pilot oil shale mine in Colorado. Sulfur hexafluoride (SF6) tracer gas was used to measure the performance of the two systems: a free-standing jet fan and a reversible fan with rigid duct. The tracer gas was used to simulate the production of mine air pollut-ants, including blasting pollutants, hot diesel emissions, free methane from surrounding strata, and methane desorbing from muck piles. The test room was 55 ft wide, 30 ft high, and 320 ft long. The performance of the two fans was similar, but the jet fan used less power. The tests showed that either system could provide effective ventilation during oil shale mining.

Jan 1, 1986