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By Mohamad Kharseh

There is general acceptance that climate change, which is the most important challenge facing humanity, is anthropogenic and attributed to fossil fuel consumption. Therefore, improving the performance of our existing energy systems and deploy more renewable energy resources is an urgent issue to be addressed. Geothermal refers to existing of heat energy in deep rock and sedimentary basins. This energy can be used to drive a power turbine to generate electricity. Traditionally, geothermal has been exploited in places with the plentiful hot water at relatively shallow depth. In the light of fact that ground temperature increases with the depth everywhere on the Earth, engineered geothermal systems (EGS) can be installed in any place to exploit the geothermal in generating energy. Unfortunately, the high exploration and drilling costs of boreholes is the main barrier to commerciality of EGS worldwide. In addition, there are technical problems associated with drilling big depth. In oil producing countries such problems can be addressed by utilizing whether active or abandoned oil or gas wells and, consequently, EGS can produce power at profit. The current study presents an analysis of a binary geothermal power generation system for commercial electricity generation in Qatar. For this purpose, two binary cycles are assumed the main difference between them is that the first one is air cooled while the other will be water cooled. The performance of the two cycles and the possibility of improvement has been shown. Economic analysis the power plant shows that the levelized costs of electricity is 3.6US¢/kWh and the pay-back time is less than 8 years.

Aug 1, 2013

By Wei Wang

The SMCO copper plant is located in DR Congo, and was designed by China NERIN Engineering Co., Ltd. The process is a typical hydrometallurgical plant with Leach-SX-EW, with the project treating the oxide minerals with agitation leaching, followed with three stage of solvent extraction and two stages of stripping, and using permanent SS cathodes to produce LME grade copper. Because of the special characteristic of the ore, what contains 2 different type of oxides (one high carbonate oxide and the other low carbonate), there are several new technical measures that have been developed and adopted for the plant. For example, different grinding, leaching, and filtering are used to treat different oxides. This paper, presents the project process, engineering design, construction and commissioning. The paper also describes some of the problems encountered during plant commissioning, such as the agitation leaching tank issues, and corrosion in the settler-mixer. This paper discusses some NERIN solutions to these problems, and explains the use of the CN filter, which is used to filter PLS to treat high level suspend solids, instead of the traditional sand filter. Finally, this paper also proposes steps / measures for further improvement for future plant operation.

Jan 1, 2014

Iron control and iron residue management and disposal are significant issues in all zinc production processes. This paper briefly reviews the most important primary zinc production routes and discusses the challenges posed by iron control in each of them. The technologies and strategies that have proven successful in controlling and managing iron are discussed. SNC-Lavalin's experience in designing and commissioning zinc plants provides a unique perspective from which to review this aspect of zinc production.

Jan 1, 2006

By G. H. Montgomery

THE PROPERTY of Aunor Gold Mines, Limited, consists of eleven claims, located in Deloro township, approximately three miles southeast of the town of Timmins. Production began in 1940 and currently the mine is operating at a rate of 485 tons per day. GEOLOGY AND MINE DEVELOPMENT The ore zone at Aunor occurs in altered lavas bounded on either side by soft talc-chlorite schist, locally known as 'soapstone'. The zone has a strike of N.80°E, dips 60° North, and varies in width from 0 to 250 feet. Within this zone the main orebody has a westerly plunge, away from the No. 1 shaft area (Figure 1). The mine is developed by a vertical three-compartment shaft from surface to the 3,082-foot horizon. Working levels are spaced at 125- foot intervals from the 625-foot to the 1,625-foot horizon, from which to tl1e 2,125-foot level the interval is 250 feet.

Jan 1, 1957

By M. S. Millman

Close monitoring of performance at each process stage, from raw material through to finished product, is vital for operational consistency and the production of high quality steel. However, many of the integrated iron and steelmaking process route stages operate under such severe conditions of temperature, dust, water, thermal radiation, vibration, pressure, vacuum, extreme dynamic events, high material flows, corrosion, erosion, electrical-noise, electromagnetic-noise, or audio-noise that, in general, it is a very difficult challenge to obtain useful information for control. Thus, state-of-the-art non-contact and remote sensors are applied to help monitor and control specific process operations. Often, these sensor systems have been developed especially for the steel industry and they are based on four principal technologies: Laser, Microwave, Electro-Magnetics and Thermal Imaging with supporting technologies such as: X-ray Fluorescence, Audiometry, Digital Image Processing, Radio Telemetry, GPS and many others. These advanced sensor technologies are reviewed with respect to their application at various stages along the integrated process route.

Jan 1, 2004

By Robert D. McKellar, Luke Frawley, Okrasa. Richard

"The resource industries in Canada are facing increasing global competition and stringent environmental regulations. This has made it essential for companies to lower operating costs wherever possible. Electrical energy rep-resents one variable cost that may be better managed and utilized, providing the user with lower operating costs, improved productivity and better yields.The utility industry is also facing changes in the way it must do business. Utilities in North America are facing the prospect of deregulation that will eliminate the monopoly they have traditionally held. This will force them to strive for lower operating costs, to maintain a competitive position and to improve customer ser-vice so as to maintain their customer base.Ontario Hydro has been working with industry for several years. Many opportunities for cost savings have been identified involving energy efficiency, process improvements and the use of new electro technologies. One useful service that the utility can offer industry is to increase the awareness of potential opportunities suited to their operations. This paper will provide an overview of some of the projects that have been implemented and those that are presently being evaluated. An electronic data-base of electro technology applications that is under development will also be described."

Jan 1, 1996

By B. K. Mishra, Subrat Kumar Padhy, B. C. Tripathy, I. N. Bhattacharya

Manganese is a difficult metal to electrodeposit due to its high electronegativity and continues to possess unique process challenges. Manganese deposits of high quality are electrodeposited on 316 grade stainless steel from sulphate solutions in the presence of organic additives such as tetra ethyl ammonium bromide (TEABr), tetra propyl ammonium bromide (TPABr), and tetra butyl ammonium bromide (TBABr). The concentrations of these additives were examined over a relatively broad range to evaluate their effect on current efficiency, specific energy consumption and deposit morphology of the electrodeposited manganese metal. A maximum current efficiency of 68% was achieved in the presence of TEABr in the bath. X- ray diffraction studies revealed that (330) (411) planes were the most preferred planes of crystal growth during manganese electrowinning at a current density of 500 A/m2 resembling alpha-manganese irrespective of the nature of additive. Scanning electron micrographs showed smooth and uniform deposit morphologies when manganese was electrodeposited in the presence of TEABr.

Jan 1, 2014

By E. Gaucher, D. C. Gagnon

"The paper refers to methods and concepts used in the computer treatment of banks of geophysical, geochemical and geological data, relating to the exploration of massive sulphides. In particular, a data bank of 400 drill holes on independent conductors can be used to calculate probability levels of intersecting a certain quantity of sulphides according to the characteristics of the conductor. Inversely one can, using the data bank and some cost assumptions, simulate and optimize the cost of intersecting a certain quantity of sulphides by selecting drill targets among conductors according to conductivity, magnetism or gravity. Problems of noise, inherent in any simulation, are illustrated in this paper by the results of a study of the nomenclature of volcanic rocks of 27 drill holes by forty geologists. Compilations of data banks are long and timeconsuming, and it would help to standardize to allow exchange of data. We believe that such efforts may result in the discovery of more mineral deposits and at a lower cost. The present study is supported jointly by SOQUEM The New Jersey Zinc Co. and Cominco Ltd."

Jan 1, 1973

By Claude Bourgoin

"The Copra massive sulphide deposit occurs as a continuous slab of ore dipping at approximately 40 degrees within a sericite schist formation. The orebody has been delineated over a distance of more than 5,000 feet down dip. This paper is mainly concerned with the mining procedure, and particular reference will be made to the use of steel mill holes and hydraulic roof supports. The gravel backfill line, which is operated both by gravity and hydraulically, is described. The paper mentions some of the operational problems, discusses the feasibility of longwall mining and presents the information obtained from stope testing."

Jan 1, 1966

By V. Bonilla-Sierra, M. Elmouttie, L. Scholtès, F. V. Donzé

In the presence of joint sets sub-parallel to a slope face, the stability of the rock mass is controlled by the shear strength of the joints. On one hand, if the joints are persistent their shear strength can be assessed according to Mohr-Coulomb criterion, assuming appropriate values for the cohesion and the friction angle on the joint surface. On the other hand, if the joints are non-persistent with their continuity being interrupted by the presence of rock bridges, their shear strength will increase considerably. In this latter case, the contribution of the rock bridges to the shear strength of the joint has to be accounted for in order to better assess the stability of the rock mass. A numerical analysis of the progressive failure of a rock slope involving a non-persistent joint has been set up based upon simulations performed using a Discrete Element Method (DEM) algorithm specifically enhanced for the modeling of jointed rock masses. Pre-existing discontinuities are explicitly accounted for in the model by using a modified contact logic that ensures an explicit and constitutive mechanical behavior of the joint planes. In addition, rock bridges can be spatially distributed along these joint planes following a prescribed probabilistic technique. Jennings’ formulation (Jennings, 1970) is considered as one of the first rock slope analysis that evaluates the shear resistance to sliding as a weighted combination of the shear resistance of the intact rock and the joint planes. The validity of this formulation is discussed in the present study. Contrary to the Jennings’ formulation, we show that tensile failure is an important mechanism, particularly as the dip angle of the sliding plane increases.

Jan 1, 2015

The writer presents a concise summary of eleven recent discoveries made in the Maritime Appalachian area, with suggestions for fur the research. This information may prove helpful to geologists working in other fields and to students contemplating further avenues of research in mining geology and exploration. INTRODUCTION THIS paper is not intended as a research study on the subject, but i. merely a brief review of eleven discoveries that have been made in the Canadian Appalachian area. Furthermore, this is not a critical analysis of the merits of any one geophysical method, but it is an un-prejudiced observation of how these discoveries were actually made and what techniques were apparently most fruitful. Some generalizations are attempted whicl1 may suggest further avenues of research in the field of mining exploration. The writer wishes to thank his colleagues in the field for their comments, which he was able to in-corporate into this paper. In particular, he is grateful to Dr. Paul Bevan and

Jan 1, 1963

By Richard P. Curtin, John M. Goris, Lewis A. Martin

Cable bolt supports are being recognized as an effective ground control system in under-ground coal mines in North America, and their use has increased considerably during the past few years. The U.S. Bureau of Mines personnel are conducting both laboratory and field tests to evaluate the performance of these supports under a variety of conditions and to establish realistic design guidelines. This paper describes efforts to evaluate the capability of cable bolts to resist the high shear forces often present in longwall operations. Shear tests were conducted on pairs of 0.025 m3 (0.88 cu. ft) concrete blocks having joint surfaces ranging from rough to smooth. Tests were conducted on blocks both with and without reinforcement with 15.2 mm (0.6 in.) diameter steel cables. During each shear test, the loads and displacements along the normal and shear axes, as well as loads on the cable, were monitored. Cableloads were determined using strain gauges attached to the outside surfaces of the barrel-and-wedge anchors used for pretensioning the cables. Test results show that a cable bolt placed across a joint more than doubled shear resistance of shear blocks having both smooth and rough joints.

Jan 1, 1996

By S. A. Bunk, E. C. Eccleston, J. J. Amsden

Fluidized bed technology has been widely applied to mineral and metallurgical processes. Over the years, modeling of fluidization technology has progressed to a level at which basic design parameters can usually be defined based on empirical correlations. In addition, scale-up considerations have become better understood, and significant advances have been made in the area of computer simulation. Despite these advances, fluidization is a complex phenomenon, and modeling tools remain limited in their ability to simultaneously model both fluidization and chemical process parameters. As a result, almost all mineral and metallurgical applications of fluidized bed technology require pilot testing prior commercial scale design. This paper outlines pilot plant testing requirements and process development considerations for development of low technical risk commercial designs.

Jan 1, 2011

By D. Verhulst

The Altair process digests ilmenite concentrate in high-chloride HC1 solution, with complete dissolution of titanium and iron. The Fe(III) ions are reduced to the ferrous form, and the solution is cooled to produce crystalline ferrous chloride. Titanium is transferred by solvent extraction into a purified, concentrated Ti stream, which is spray-hydrolyzed to produce TiO2 hydrate. The hydrate is further calcined with additives to generate a high-quality pigment. All the chloride streams are recycled. In the original flowsheet, the iron chloride is pyrohydrolyzed by spray roasting to regenerate 18% HCl, which is subsequently converted to HC1 gas and water by pressure-swing distillation. A modified flowsheet includes an alternative to iron chloride spray roasting, producing more concentrated HCl and decreasing the amount of solution to be distilled. Improvements in digestion, solvent extraction and final pigment production are also introduced. A 100 t/y pilot plant is being built and will test the new concepts and confirm the overall water, acid and impurity balances of the process.

Jan 1, 2006

By Martin Junker

This Notwithstanding all the debates on climate change and renewable energy, coal remains the world's no.1 primary energy source even in the 21st century. In 2011 alone, total output rose from 420 million t to around 6.6 billion t. Similar growth rates are also expected for the next few years. In order to meet demand, new seams are being tapped and others mined far more extensively. In most cases, this means a move from open-cast to deep mining, and extracting coal from ever greater depths. At the same time, extraction processes such as the room and pillar method are being replaced by longwall mining, which significantly increases seam yield and therefore output. The depth of extraction with new, modified mining methods is increasing rapidly around the world - in most countries, much more rapidly than the corresponding expertise. A trade in mining expertise has therefore developed alongside the coal trade proper. Germany relies on coal imports, but can export mining industry services and advanced mining equipment. Geological conditions in the Ruhr and Saar coalfields forced Germany to drive forward development of deep working for hard coal years ago. For 30 years now, Germany has been mining hard coal at depths of over 1,000 m, and excavation is now at depths up to 1,600 m. Deeper extraction and more extensive excavation posed new challenges for both miners and equipment. Intelligent logistics, modern roadway development methods and longwall mining with ploughs or shearers combined with optimised process coordination offered pioneering solutions - solutions to enable costeffective coal extraction in the long term without compromising safety. Countries such as Russia, the Ukraine, China and the Czech Republic, where extraction is now reaching similar depths, can now benefit from this experience: they do not need to go through the same process of trial and development, but can draw on Germany's findings and ultimately save on costs. Now, Germany is offering this knowledge and experience on the international market on a client- and deposit-specific basis to continue providing mining countries with safe and cost-effective coal mining solutions and secure the energy supply. The presentation gives a number of examples of how international mining companies have used expertise from Germany to better meet the challenges of deep mining.

Aug 1, 2013

By J. E. Gill

Discovered in 1952, the deposits have been explored by diamond drilling on and near a group of islands in lake Nipissing and from under-ground workings. The ore mineral is a uranian pyrochlore. It occurs in breccia zones in association with calcite, apatite, a?cmite, feldsiiars, biotite, magnetite, sulphides, and fluorite in varying amounts. The pyrochlore concentrations occur in a steeply-dipping gneiss series with some crystalline limestone. Trends indicate a ring structure 114 miles in diameter. The main ore zone shows evidence of repeated brecciation and a succession of replacements .giving rise to a complex of rock types. Pegmatite and lamprophyre dykes cut the ore as do calcite-fluorite veins and later faults with small displacements. Columbium and uranium occur al-most exclusively in pyrochlore, but the proportions vary. There is no tantalum and only small amounts of titanium.

Jan 1, 1957

By W. A. Bell

The Carboniferous system of rocks in the Maritime Provinces include as workable mineral and organic substances, gypsum, anhydrite, salt, coal, building stones, grindstones, limestones, brick-clay shales, fire-clay shales, oil shales, etc. The system is, therefore, pre-eminently of economic value to the provinces in which it occurs, and the more knowledge we may gain concerning it, the more we may be prepared to aid in the development of these useful substances. For this purpose it is not sufficient to state that the ground upon which we stand is underlain by Carboniferous rocks. In-discriminate digging or drilling will not open many new mines of wealth, however difficult it may be to dampen the optimism of gamblers. For mineral wealth has not been scattered in the rocks haphazard, now here, now there, but its distribution has been the result of natural earth forces acting at intervals throughout the countless millions of years that have elapsed since our planet was born. As regards the majority of metalliferous deposits, the earth forces involved have resulted in the penetration of surface or sub-surface rocks by molten rock-matter and associated mineral solutions from deep-seated sources. But the economic Carboniferous deposits that have been mentioned are themselves types of bedded surface rocks rather than immigrant deposits, and their formation and geological history is closely related to that of the rocks with which they are interbedded.

Jan 1, 1924

By Jie Zhu

Coal bumps are a special form of release of geologic strain energy that has already been one of the most dangerous hazards to underground mining safety in China. A number of coal-bump models have been developed to quantify coal failure under assumption that a bump is a kind of non-gas induced outburst. However, some technical experts in charge of micro-seismic and gas monitoring have found unusual gas emissions before and after bump, which suggests that it is possible for gas to trigger coal bumps. Considering the coal reservoir as geological body composed of the coal matrix and gas, a new model based on Lippmann?s bump model is proposed to understand the initiation of coal bumps. The redistribution zone from excavation of a roadway has been calculated and analyzed regarding its relation with mining depth. It is shown that high gas pressure may push the coal seam to overstep the critical state due to extension of the plastic disturbed zone, and this is harmful to the stability of coal seam. This model successfully explains the bump phenomena of the Xinzhouyao mine at shallow depth.

Aug 1, 2013

"The QEMSCAN system is the third generation of automated mineral analysis systems that began with the QEM*SEM at CSIRO 30 years ago (Butcher et al. 2000). It is now a successful commercial instrument with 39 instruments in operation around the world. Back Scattered Electrons (BSE) and Energy Dispersive (EDS) X-Ray spectra are used to create digital mineral images with mineral identification occurring online. Low-count EDS spectra are used preferentially to BSE brightness, allowing minerals to be accurately identified by chemical composition. Individual minerals or groups of similar compositions are identified by comparison to a comprehensive mineral database incorporated into the QEMSCAN software. Optical mineralogy and Scanning Electron Microscopy is a metallurgists’ tool for determining the ore process mineralogy and delivering a better flowsheet. These techniques have limitations, provide limited information and sometimes fail to provide representative information. In contrast, QEMSCAN provides information on the nature and occurrence of all mineral species present plus the liberation characteristics, looking at thousands of particles in the sample presented. Some of the data presented includes:• Particle and grain sizes• Dominant mineral species• Particle shape• Calculated metal content• Density• Deportment of elements of interest between the mineral phases• Quantitative mineralogy• Mineral associations, locking and liberation• Textural relationships (particle images)It can also be used on concentrates, polished sections or drill core. This is a significant improvement in ore characterisation providing lithology, mineralogy, liberation, ore grade and porosity from a sample. Theoretical grade-recovery curves can be created to be mineralogically limited from QEMSCAN analysis which, when compared with metallurgical results, are valuable in evaluating whether liberation or chemical selectivity is driving flotation performance. A number of case study examples are given where the QEMSCAN had a significant bearing on future project development at an early stage of exploration and mine development."

Jan 1, 2012

By D. M. Maijer, S. M. Mohseni, A. B. Phillion

The microstructure evolution kinetics of aluminum alloy B206 during artificial aging has been investigated using non-isothermal calorimetry. A combination of differential-scanning calorimetry (DSC) and tensile tests have been utilized to develop an Avrami model to predict the precipitation kinetics as a function of the thermal processing parameters. The Avrami coefficients, found based on a Kissinger analysis, compare well against those reported in the literature for aluminum-copper alloys. The rapid precipitation kinetics predicted by the Avrami model at temperatures higher than 200°C were assessed through a qualitative comparison against hardness measurement results. In contrast to the continuous hardening observed at 150°C, the material softens with continuing heat treatment at 250°C resulting in an overaged state. This can be attributed to the rapid precipitation kinetics at this temperature, leading to the termination of the precipitation-hardening effects at early stages of artificial aging.

Jan 1, 2015