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By A. Galley, R. Tosdal, F. Robert

The Canada Mining Innovation Council (CMIC) Exploration Innovation Consortium developed a 10-year business case for developing new discovery criteria, exploration techniques, and better data management and analysis to improve exploration success in deep, remote, and covered terrains. Within this context, the CMIC devised a five-year project proposal to create improved multiparameter exploration tools to detect ore systems and more efficient vectoring toward high-grade mineralized cores. The Footprints project was approved March 2013. More than CAD$13 million funding was provided through the CMIC-led joint sponsorship from 30 companies and the Natural Sciences and Engineering Research Council. Consistent industry leadership and integration of dedicated industry and academic expertise has the project on track for reaching its well-defined objectives.

Jan 1, 2014

By Gleason

"From June 16 to 19, more than 1,400 tunneling and underground construction professionals gathered in Chicago, IL for the bienial Rapid Excavation and Tunneling Conference (RETC). There, they were greeted by a full technical program and an exciting exhibit hall that provided a comprehensive look at the world’s bustling tunneling and underground construction industry.The successful conference was a reflection of the industry itself, which is to say, busy. As much of the world has begun to focus on creating a cleaner and greener environment, the global tunneling industry has seen an uptick in infrastructure projects move from design-build to construction phase. With a global shift away from the use of fossil fuels, major cities around the world are looking to increase public transportation options, which leads to the need for more transportation tunnels. And as urban populations continue to grow, the need for clean water calls for more tunnels, and as urban footprints continue to expand, the need to increase and update combined sewage overflow tunnel grows with them.During two and a half days, more than 20 sessions covering all of these topics were presented at the Hyatt Regency in Chicago, many to packed rooms in which every seat was taken and people were standing along the side and back walls.RETC is a biennial conference and one of the largest in the North America for the tunneling and underground construction industries. As such, it hosts a robust exhibit floor. This year 172 vendors occupied 205 booth spaces. The exhibit included everything from tunnel boring machine manufacturers, like Robbins and Herrenknecht, to the companies that supply all kinds of parts and services to the industry."

Sep 1, 2019

By C. Moreland

Fluidized low-temperature carbonization of coal, a recent development, offers a possibility of reducing fuel costs of coal-burning electric ?generating plants. The Research Council of Alberta have built a pilot plant and are conducting a programme to -develop a carbomzation plant for Alberta sub-bituminous coals which will produce char suitable for use as a .boiler fuel, and tar of a potentially high value as a ?chemical raw material. The economies of the process as a whole, and the value of the tar, have yet to be assessed.

Jan 1, 1958

By K. Andres

This paper presents the vibrating mill technology and summarizes the grinding principle of ultra fine grinding. In addition, a variety of operations is described and the benefits of these different operating modes? product size and efficiency are specified. A case study of an industrial application is presented to show the integration of vibrating mills into grinding circuits. The primary focus is the overall process scheme of this technology, the installation and operating costs, as well as the design parameters required for best performance. The vibrating mill can be used in a wide range of applications for process engineering duties. For a wide range of applications, from soft to extremely hard products, which require ultra fine grinding, surface activation or homogenization, the vibrating mill is well proven. Due to its easy operation, versatility and operation efficiency, the PALLA? vibrating mill gains in importance in the mineral processing industry. Keywords: Coal, comminution, grinding, mineral processing

Jan 1, 2010

By William P. Blake

THE use of diamonds upon a large scale in drilling rocks, and the substitution to a certain degree of rotary diamond drills for the ordinary steel percussion drills, marks a new era in the art of mining. Since the invention by Leschot of the diamond drill, it has steadily advanced in its utility and range of application, and in the appreciation of miners and engineers. I t must be claimed as one of the many gifts of science to the arts ; and it is, in particular, one of the fruits of the scientific education given at the Ecole Centrale, at Paris. Members are all, doubtless, more or less familiar with the construction of the drill and of the machinery by which it is applied in boring. I t is, therefore, my present purpose only to direct your attention to some recent marked improvements, made by the American Diamond Drill Company, by which the economy and efficiency of the machines have been increased. Form of Bit.-The annular or ring form of the drill-head or bit was, I believe, the earliest; and it is still in use, without essential modification, wherever it is desired to obtain a sample " core" or specimen of the rock traversed. But for mere drilling, regardless ~f the preservation of a test-core, a solid-head bit is preferred, except for very large holes. Until recently, these solid-head bits were made with a pointed cutting face shaped like an obtuse cone. This form was assumed to be the best, being most in accordance with the experience obtained with percussion drills. I t is found, however, that the exact reverse

By Geo. W. Bain

PRODUCERS of building stone have had to seek new and attractive uses for their output to supplement the diminished orders for standard products. Lunar is the direct result of the need of new outlets for marble and is. probably the most ingenious and attractive type to reach the market in a quarter of a century. It is a highly translucent stone which retains the same glistening sparkle in transmitted light that marble exhibits by incident rays. This sparkle sets it apart entirely from translucencies made of glass or even onyx, alabaster, and the distinctive exceedingly fine textured calcite marbles produced in Alabama and quarried formerly in northern Vermont and Quebec.

Jan 1, 1936

By Gavin Ritson, Chris Ward

"The oil sands industry is still fairly young with the first viable oil sand operation having been started in Alberta in 1960. Since then numerous modifications and improvements have been tried and implemented. The current process makes use of high velocity pumping of oil sands slurry with hot water (hydrotransport) to achieve separation of bitumen from the sand.A number of the oil sands processes have been adapted from unit operations that are used in mineral processing, such as crushing, screening, flotation, cycloning and thickening. This paper outlines a typical oil sands process flowsheet and investigates the differences and similarities in technologies and costs to other mineral processing industries. It also considers the very large throughputs required, and presents some of the difficulties and challenges currently faced by the industry as a result of high demand for oil and environmental pressures.INTRODUCTIONOil sands (also known as tar sands) deposits are found throughout the world. The Athabasca Oil Sands deposit in Aberta is the largest of these. Oil sands consist of a mixture of crude bitumen (a semi-solid form of crude oil), silica sand, clay minerals, and water. The Athabasca, Peace River and Cold Lake deposits cover 141,000 square kilometers and contain about 1.7 trillion barrels (270×109 m3) of bitumen in-place, comparable in magnitude to the world's total proven reserves of conventional oil"

Jan 1, 2009

By J. Redstone, A. R. Laplante

Sidbec-Normines operates six large iron ore concentrate regrinding mills in parallel and open circuit at its Port-Cartier pelletizing plant. Grinding kinetics in these mills were characterized for slurry densities varying between 70 and 89% solids, using a lumped parameter size discrete model. Optimum grinding conditions were encountered at 83.5 to 84% solids. Higher densities decreased the normalized selection function and increased slurry short-circuiting, yielding a sharply coarser mill discharge. At lower slurry densities, the normalized selection function decreased and the mill discharge coarsened slightly. The grinding kinetic model predicted particle size distributions within the mill. These were found to vary significantly from the feed to the discharge end. This is likely to cause nonlinear breakage kinetics.

Jan 1, 1985

By D. R. Dolinar

Geogrids can be used as surface control on both the roof and rib in underground mines to prevent the fall of small pieces of rock and material from between the primary supports. The use of screen material such as geogrid can significantly reduce the number of ground fall injuries caused by these small rock falls. Because of the potential for reducing injuries through the use of screen, the National Institute for Occupational Safety and Health (NIOSH) has conducted tests on screen materials including geogrid to determine their support characteristics and identify parameters that can affect their performance with respect to maintaining broken or failed rock. A specially designed test frame installed in the NIOSH Mine Roof Simulator (MRS) has been used to evaluate the load and stiffness characteristics of the screen material. Two types of geogrids with various designs have been tested-a polyester yarn and a polypropylene grid. The load-displacement characteristics of these grids were determined and the load capacity and stiffness were calculated through 20in of displacement. The load capacity and stiffness of the geogrid in general are shown to be related to the ultimate tensile strength of the screen material.

Feb 27, 2013

A novel solvent extraction process, called the SOHNEX process, has been developed at the University of Utah. In this process, the organic and the aqueous phases flow countercurrently in a horizontal vessel, and the emulsion between the two liquid phases is generated by high-velocity gas jets injected at the bottom. The gas jets are located at certain intervals along the bottom of the vessel with phase disengagement zones on either side of the plume zone created by the gas jet. The system is simple, having no mechanical moving parts or complex internal structures, and yet provides good contact between the phases with minimal backmixing. Tests have shown that emulsions with a wide range of specific interfacial area, including that typically encountered in mixer-settlers, can be generated in this process. It has significant built-in flexibility of operation including the control of the flowrate and hold-up of each liquid phase. The SOHNEX process overcomes the difficulties in the operation of conventional solvent extraction equipment such as mixer-settlers and column extractors. A major advantage of the SOHNEX process is that the energy of mixing can be closely controlled by adjusting the strength of the gas jet. This allows an optimal control of the drop-size distribution of the dispersed phase and thus the specific interfacial area. The process is continuous, and any number of extraction and separation stages may be built into a single vessel. The gas can be recirculated in a closed loop, thus eliminating solvent loss and mist problems, especially for high-temperature operations. The SOHNEX problem can handle solutions that contain suspended solids and that form third phases. The simplicity of the equipment and operation with low maintenance will mean much reduced capital and operating costs as well as low environmental risks and improved safety. The SOHNEX process has been tested for continuous copper extraction from a dilute solution. Calculations also showed that uranium and other radioactive elements can readily be extracted in a small unit of the SOHNEX extractor while satisfying the nuclear criticality condition.

Jan 1, 2000

By Ian J. Graham

Brothers volcano, in the southern Kermadec Arc, is host to two hydrothermal vent fields with very different geology, permeability, vent fluid compositions and mineralogy (see de Ronde et al. and Ditchburn et al. this volume). The NW caldera site contains mineral deposits (sulfide chimneys and crusts), which are either Cu-rich (?magmatic?) or, more commonly, Zn-rich (?epithermal?). The lower cone site, in contrast, is characterized by native sulfur mounds and spires. It has been proposed (see de Ronde et al. this volume) that the metals, especially Cu and possibly also Au, enter the hydrothermal system via injection and degassing of magma and/or the dissolution of metal-rich glasses. They are then transported rapidly upwards via magmatic volatiles along long (c. 2.5 km), narrow (c. 300 m diameter) pipes, consistent with evidence of vent fluids forming at higher than hydrostatic pressures, at relatively shallow depths. The NW caldera and cone sites may represent stages along a continuum between magmatic-hydrothermal and water/rock-dominated end-members. In this context, investigation of melt inclusions in conjunction with other geochemical and petrological research was carried out to ascertain the metal transporting conditions that may have led to mineral deposition and ore formation. Sixteen melt inclusions in plagioclase were analyzed for their chemical compositions from a typical cone dacite sample using LA-ICPMS at the University of Tasmania. The inclusions are typically glassy and commonly occur with other inclusions such as apatite, clinopyroxene, zircon, magnetite, sulfides and/or low-density fluids (Fig. 1). Major (XRF) and trace element (ICPMS) analyses were performed on whole rock samples collected during the 2005 Shinkai 6500 expedition. Haase et al., (2006) has also reported EPMA glass analyses from cone dacites, which may be used for comparison (Table 1). [ ]

Jan 1, 2010

By H. O. Seigel

This is an introductory paper on a new method of prospecting for mineral deposits which has been developed by Scintrex Limited. The method, which we call Luminex, for luminescent mineral exploration, is based on time- resolved mineral luminescence created by an ultraviolet light source. It has the ability to detect and resolve a group of key minerals which are either ore minerals themselves, or more often, are accessory or pathfinder minerals for certain types of economic ore deposits. Fortunately, these minerals are commonly found at the earth's surface, even in areas of considerable weathering. The method extends the range of mineral deposits which are remotely detectable from the air to include those such as tungsten, tin, molybdenum, gold and bedded lead-zinc deposits and, is therefore, a natural supplement to our three classical methods of airborne geophysics.

Jan 1, 1983

By Raymond S. Weimer

Of the several characteristics of a coal that influence its suitability for use in a given piece of burning equipment, the clinkering and slagging characteristics of the ash of the coal are highly important. They determine the maximum rate at which the coal may be burned on a stoker or in pulverized form without difficulty from damage to metal parts, from erosion of refractory walls, or from stoppage of gas passages by accumulation on the tubes. They also determine the minimum rate at which a slag-tap furnace may be operated without difficulty in removal of the ash in fluid form. Need for a Better Criterion In common with other producers and users of coal, the Northern Illinois Coal Corporation has long used the available methods for the measurement of the clinkering characteristics of coal ash, chemical composition and fusion temperature of the ash, as criteria for the selection of coal that would suit the particular requirements of its customers. These two available criteria have greatly helped in the problem of selection but it is unnecessary to dwell upon the fact that they are not completely adequate for the purpose. The composition of the ash and its clinkering tendency vary widely over the company's mining area. In a certain period, some years ago, an unusual amount of severe clinkering of the ash of coal shipped made extremely acute the need for a better criterion of the clinkering that might be expected. It was also desirable that the criterion result from a reasonably rapid method, so that the clinkering characteristics of the coal would be known before shipment. Complaints on the severe clinkering of the ash came from only a fraction of the output of the mine but the occurrence of the clinkering seemed quite unpredictable. Attempts to relate the chemical composition of the ash and the fusion temperatures to the clinkering were unsuccessful. Coal from the area of the mine in which the fusion temperature of the ash was the lowest gave the least trouble from clinker-ing. Chemical analysis of the ash from that section giving the most trouble showed high contents of iron and low contents of silica, but frequently these were not greatly different from those of coals that gave little trouble from clinker. Aside from the clinkering difficulty, the coal was quite satisfactory. The ash content was normal and high rates of burning could be obtained, but again and again such severe clinkering would occur that the furnace would be shut down because of the accumulation of clinker. Examination of the clinker from the customers' plants showed that the clinkers that adhered to the grates and fouled the fuel beds were hard, flat, dense, and usually dark in color. Coal that was satisfactory gave clinkers that were softer, bulky rather than flat, of low density, and usually lighter in color.

Jan 1, 1944

By Raymond S. Weimer

Of the several characteristics of a coal that influence its suitability for use in a given piece of burning equipment, the clinkering and slagging characteristics of the ash of the coal are highly important. They determine the maximum rate at which the coal may be burned on a stoker or in pulverized form without difficulty from damage to metal parts, from erosion of refractory walls, or from stoppage of gas passages by accumulation on the tubes. They also determine the minimum rate at which a slag-tap furnace may be operated without difficulty in removal of the ash in fluid form. Need for a Better Criterion In common with other producers and users of coal, the Northern Illinois Coal Corporation has long used the available methods for the measurement of the clinkering characteristics of coal ash, chemical composition and fusion temperature of the ash, as criteria for the selection of coal that would suit the particular requirements of its customers. These two available criteria have greatly helped in the problem of selection but it is unnecessary to dwell upon the fact that they are not completely adequate for the purpose. The composition of the ash and its clinkering tendency vary widely over the company's mining area. In a certain period, some years ago, an unusual amount of severe clinkering of the ash of coal shipped made extremely acute the need for a better criterion of the clinkering that might be expected. It was also desirable that the criterion result from a reasonably rapid method, so that the clinkering characteristics of the coal would be known before shipment. Complaints on the severe clinkering of the ash came from only a fraction of the output of the mine but the occurrence of the clinkering seemed quite unpredictable. Attempts to relate the chemical composition of the ash and the fusion temperatures to the clinkering were unsuccessful. Coal from the area of the mine in which the fusion temperature of the ash was the lowest gave the least trouble from clinker-ing. Chemical analysis of the ash from that section giving the most trouble showed high contents of iron and low contents of silica, but frequently these were not greatly different from those of coals that gave little trouble from clinker. Aside from the clinkering difficulty, the coal was quite satisfactory. The ash content was normal and high rates of burning could be obtained, but again and again such severe clinkering would occur that the furnace would be shut down because of the accumulation of clinker. Examination of the clinker from the customers' plants showed that the clinkers that adhered to the grates and fouled the fuel beds were hard, flat, dense, and usually dark in color. Coal that was satisfactory gave clinkers that were softer, bulky rather than flat, of low density, and usually lighter in color.

Jan 1, 1944

By Thor Skjeggedal

The Norwegian contracting firm A/S Høyer-Ellefsen has for the last 2.5 years carried out substantial pregrouting in a 7600m long tunnel just outside the city of Oslo. This has been done to avoid groundwater lowering and consequent damage to surface structures. A WIRTH TBM is used in combination with a 2 boom Atlas Copco hydraulic jumbo for the drilling of groutholes in front of the machine. The detailed procedure for the drilling and grouting will be discussed, and the results obtained will be presented.

Jan 1, 1981

By J. Q. Chen

The elastic-plastic behavior and the fracture mechanisms of two 2198 Al-Cu-Li thin sheets are investigated. The first material (2 mm thick) is in a recrystallized state after cold rolling. The second material (6 mm thick) is hot rolled and has a fibrous grain structure. The two materials are studied in both T351 and T851 conditions. Tensile tests are carried out along different sheet directions using flat and notched specimens. Fracture resistance was characterized using Kahn tear specimens and M(T) panels. Macroscopic fracture surface of smooth tensile specimens depends not only on testing material but also on the loading direction. For Kahn tear specimens, fracture is initiated in a small flat triangle whereas slant fracture is observed during crack propagation. Fracture mechanisms were investigated using scanning electron microscopy (SEM) and X-ray 3D tomography.

Jan 1, 2011

By K. C. Ko

The pit slope angle dictates the economics as much as the depth of the pit. Steeper slope provides more ore reserves, at the same time, the steeper slope presents higher probability of instability and associated maintenance problems. While large open pit mines mostly belonged to nonferrous metals in the past, other mines are becoming deeper as the mine economics permits deeper mine operations, Such minerals include coal, uranium, phosphate, and others. There are some basic differences between an open pit slope and slopes that are encountered in usual civil engineering work such as dam embankments and highway cuts (Figure 1). The stability of the civil engineering slope changes continuously with time due to ground-water movements, weathering, etc. But the stability of the open pit slope (Figure 2) changes more drastically day-to-day or even hour-to-hour, These changes occur because not only is the slope geometry being continuously changed by the mining operation, but also different geology and geologic structures are being exposed on the slope. Even when a particular slope area is not presently being mined, excavation in adjacent areas can affect the general condition of that slope area. A pit will experience some slope failures during its life.

Jan 1, 1977

The Resource Management Act has been in force now for approximately ten months. This Act, and the Crown Minerals Act which accompanied it, have substantially changed the manner by which mining operations and other resource uses obtain access to resources and are subject to controls of their environmental effects. This paper briefly summarises the key elements of the regulatory provisions of the Resource Management Act. It identifies the types of resource consents required, and discusses these and procedural matters in relation to mining in Otago. It addresses the transitional provisions and highlights inconsistencies and difficulties in the implementation of these provisions. This paper identifies potential future developments in the planning and regulatory environment relating to mining in Otago.

Jan 1, 1992

By A. Plugatyr, C. P. Baxter

"Bessemer matte iron content is a critical process parameter that needs to be closely monitored and controlled in order to achieve optimal Ni/Cu smelter returns. Current process control practices during Ni/Cu converting often rely on visual observations and typically involve matte sampling to confirm that target composition was reached. A high-level techno-economic analysis study was carried out to evaluate potential direct benefits of advanced process control during the final stages of Ni/Cu matte converting. The results indicate that the magnitude of direct benefits will largely depend on matte iron control practices already implemented as well as matte iron set point. Preliminary assessment suggests that under the assumptions used in this study, implementation of advanced process control can potentially result in additional revenues ranging from several hundreds of thousands to tens of millions of US dollars per year per converter producing about 200 tonnes of Bessemer matte per day based on Ni, Cu, and Co metal recoveries alone.INTRODUCTION Real-time measurement of molten metal elemental composition, arguably, remains one of the key unresolved issues impeding full automation and real-time optimization of pyrometallurgical operations in different industrial areas, including non-ferrous metals and ferro-alloys. In particular, current process control practices during Ni/Cu matte converting often rely on visual observations and typically involve matte sampling in order to confirm target matte composition. In addition to being time consuming, this approach relies heavily on operator experience and diligence, and, therefore, requires continuous performance and quality control efforts. For instance, the need to improve quality of the Bessemer matte (BM) at the Copper Cliff smelter has prompted an impressive staff engagement and training campaign that was carried out by Vale’s team in the late 2000’s (Zanini, Wong, & Cooke, 2012). This training exercise was executed to address the compounded effect of several operational challenges, namely demand for higher throughputs, changes in the feed concentrate composition, increased feed variability, loss of process knowledge and expertise due to retirement, as well as lack of a comprehensive approach to improving the overall performance of the flowsheet rather than meeting production targets for intermediate products. Although the campaign was very successful and has resulted in significant improvements in the Bessemer matte quality, it has also highlighted the need to move away from “the-art-of-converting” and develop analytical tools that would enable real-time process monitoring."

Jan 1, 2018

By H. H. Rachford, J. Douglas, D. W. Peaceman

A numerical solution of equations describing two-phase flow in porous media shows promise in providing a technique for predicting the displacermet from satlds of oil by water or gas. The description includes the influence of relative permeability, fluid viscosities and densities, graviry, and capillary pressure, and, tholrgh tested ortly for two-dimensional cases, should be eqlmlly applicable in three-dimensional geometry. Two memorical methods ore presented: the first method is quite general in its applicability; the second method can be used only with certain types of boundary conditions but requires less computing. Comparisons of computed results with data from Inhoratory models are presented. These data were taken on a water flood of a strarified model and on water floods of a five-spot model for favorable and unfavorable mobility ratios. On the stratified model, excellent agreement with recovery at breakthrough was obtained; agreement with recovery after breakthrough was poor. In the five-spot model, good agreement was obtainecl with recovery at and after breakthrough. The purpose of this paper is twofold: first, to present a reservoir engineering method requiring knowledge only of rock geometry and the normally measured rock and fluid properties for calculating the multi-dimensional flow of water displacing oil from porous, water-wet rock containing connate water; and, second, to investigate the validity of the method by comparing results of calculations with previously observed displacements in laboratory models. The availability of such a verified technique of reservoir analysis would afford major advantages. First, it would demonstrate that the fundamental macroscopic concepts of two-phase fluid mechanics, i.e., relative permeability and capillary pressure, yield an adequate description of the physical process. Also, since most reservoir rocks appear to be water-wet and contain connate water along with oil, it would provide a method of technical and economic value for calculating the course of oil displacement by water directly from measured reservoir and fluid properties. It is important to emphasize that the calculation is subject only to the limitations of detail and precision of reservoir information, but not to limitations introduced by simplifying assumptions. Further, it would providc almost the only means of examining the influence of factors such as the size and extent of reservoir inhomogeneities and uncertainties in the basic reservoir data. Knowledge of this influence is essential in stating quantitatively the detail required to define a reservoir and in establishing the relation between the uncertainty in the definition of reservoir properties and the reliability of predicted performance. Moreover, in the process of solving a particular problem much detailed information would become available about the displacement process. For example, at each point in the reservoir for all stages of the displace ment. the calculations would yield not only the water and oil saturations but also the direction and magnitude of fluid velocities and the local fluid mobilities. Such dctail is potentially of great value in giving insight into the mechanics of particular displacements. The development of such a method has long been the goal of research in the application of numerical an-alysis to petroleum reservoir enginecrinz. The most complete treatment of the displacement process published to date is that of Douglas. Blair, and Wagner,' which, however, was limited to flow in a single dimension. The method presented in the present work is hascd on the numerical solution of a finite difference analogue of the multi-dimensional differential system describing the displacement process. Although current work has considered only displacement of oil by water from water-wet sands, the differential system for other immiscible displacements, such as gas displacing oil with which it is in phase equilibrium, is quite similar. It should therefore be expected that the technique described will be applicable to displacement by gas as well. The description of the simultaneous flow of fluids through porous media in terms of relative perrncability and capillary pressure has been adequately discussed in the literature and standard textbooks. Sec, for exampje, Muskat. Chapter VII.'