Search Documents

By Donald V. Currie

"The Alberta and Northwest Chamber of Mines was founded in Edmonton, Alberta in 1935. The organization represented private sector mining explorers and developers in the province and north west Canada. The Chamber aided and abetted the establishment of the two territorial mining associations. Because of corporate human resource department creation by north of sixty mine operators, the Chamber refocused on Alberta and broadened its perspective to include activities beyond mining. In 1977 the name changed to the Alberta Chamber of resources. The slogan (in more modern terms vision, mandate, goal, etc) remains as Orderly Development of Canada's Resources.The sixty-three year reputation of the Chamber, built on volunteer rather than staff contribution, is the principal reason for any success. The key has truly been the reputation, not an image, as all activities have been solution oriented.This presentation provides insight into the structure and methodology applied by the organization, and reviews some of the successes and failures during the period 1985 to present. Examples discussed include:• Canada-Alberta Partnership on Minerals 1992-1995• Regional Upgrader Business Plan• National Oil Sands Task Force• Lakeland and Waterways Railway"

Jan 1, 1998

"Yara Siilinjärvi in Finland is the Western Europe's only apatite mine. Annually it produces one million tons of apatite concentrate, which creates 10 million tons of tailings. At the beginning of 2017, Yara replaced their conventional TSF with a new tailings treatment plant, which increased the solids content of the slurry from 45–48% to 66–68%, making it possible to deposit as a paste. This extended the life-span of the current TSF from 2020 to 2035. This paper presents the storyline of the Yara paste plant project. The project began with laboratory testing and then progressed to pilot-scale thickening and beaching trials. After successful pilot trials, the final process design was implemented. Process automation played a key role in the project. An advanced control system is needed to maintain process stability and the desired operation point in various operational circumstances. Since commissioning the paste plant has been running consistently with an underflow solids content of 66-68%, with average beach slope angles of 3.5 degrees in the tailings disposal area. Robust thickener operation also leads to the trouble-free high-density pumping and high availability of the plan. During first year of operation the plant’s availability has been very good, over 97%, and currently, the plant is operated remotely from the main concentrator plant.INTRODUCTION The Yara Siilinjärvi Plant is owned by Yara International, a Norwegian fertiliser company. Yara Siilinjärvi is Western Europe's only apatite mine, and it primarily produces apatite concentrate for its Siilinjärvi phosphoric acid plant. A portion of the concentrate is also dried and shipped to other Yara fertiliser plants. The site annually produces one million tons of apatite concentrate, which creates approximately 10 million tons of tailings. Extending the lifespan of the 1150-hectare tailings storage facility has been studied in Siilinjärvi for a long time. The aim has been to use the same tailings area footprint, without any new land purchases or major dam increases. An important part of the process has been to study the possibilities for using new technologies, especially thickened tailings technology (Ruhanen, 2014)."

Jan 1, 2019

By V. Aitken

Line-of-sight radio control has received widespread acceptance for use in many mining methods because today’s technology offers improved economics and personnel safety. Significant advances in higher autonomy for mining machines are not currently seeing widespread use even though they offer great future potential. With autonomous capabilities being a longer-term goal, a logical sequence of advances based on TeleRemote control is proposed. Under Tele - Remote control, the operator is in direct control of the machine at all times. Three levels of Tele - Remote control systems are presented including line-of-sight, extended line-of-sight, and full load-haul-dump applications. Distributed control and sensing subsystems arranged in a vehicle control area network support incremental system expansion through the three levels of TeleRemote control and prepare the machine for integration of higher levels of automation as mature technology becomes available. This approach allows full exploitation of today’s mining automation technology with a flexible future growth path.

Jan 1, 1998

By M. S. Diederichs, J. Oke

Surface limitations and a need for more direct transportation routes require serious consideration be given to the development of underground construction works in geotechnically unfavourable conditions. Due to geographical and logistical limitations, the construction of these underground works is restricted to difficult ground conditions that require temporary pre-support before excavation in order to avoid tunnel collapse or severe surface settlement. One type of pre-support is the umbrella arch system, which has been gaining popularity due to cost and time commitment in comparison with other pre-support systems (e.g., ground freezing). The umbrella arch system has been employed with significant frequency around the world, yet without a complete understanding about the mechanical response of the system. As such, literature has found the temporary support system to be both under and over designed with regard to safety and/or economical impact. The authors of this paper have made three major contributions to increase understanding of the umbrella arch system and to help optimize the design process. Firstly, the authors have developed nomenclature in order to categorize and define umbrella arch elements and systems, which also stimulated the creation of the empirically driven Umbrella Arch Selection Chart. Secondly, the authors have established a design methodology that is primarily based on advanced numerical modelling techniques to aid in the optimized design of the umbrella arch arrangement for site specific conditions. Thirdly, the authors have developed a semi-analytical model for umbrella arch systems employed in squeezing ground conditions by incorporating elastic foundation theory as well as convergence confinement theory. These three major contributions to such a widely employed tunnelling pre-support system will be introduced and explained in detail, and will include discussion of how each is incorporated in the complete tunnel support design process and throughout the construction and monitoring phase of a project.

Jan 1, 2015

By Anthony A. Zoobkoff

Gotcha! ? What Did I Just Agree To? ? You can?t repeat or use anything you heard. ? Did you agree before you knew what you were going to be given, told or shown? ? If you knew what you were to be given, told or shown, would you have still agreed?

May 1, 2013

By Edith Lafontaine

Modern underground mines operate fleets of mobile production equipment including drill jumbos, long-hole drills, load-haul-dump machines, trucks and bolters. Their availability has a substantial impact onto production cost and thus onto mine profitability. Through appropriate collection of pertinent data and information, use of adequate performance measures and their analyses, mine operators can identify the most promising and cost effective opportunities to get more from their equipment and to reduce the overall cost. This paper presents results of the study aimed to review and analyse means and measures used to quantify equipment availability and its contributing factors (reliability, maintainability and maintenance support) in several Canadian underground mines. It overviews current reporting procedures, sources, quality and quantity of the data and information collected as well as examines performance measures and their definitions used by the surveyed mines. Problems concerning data acquisition as well as meaningfulness and usefulness of the above mentioned metrics are also discussed. The paper concludes with some suggestions and recommendations concerning several aspects of equipment availability assessment. It is believed that the latter may become a more useful tool for mine operators in their efforts to reduce production cost than it seems to be the case at present.

May 1, 2007

By Andrew L. Mular, Robert P. Edwards

"The operation of flotation circuits is often regarded as a combination of art and science. Expert systems offer a method by which the art may be captured and supervisory control of flotation circuits fully realized. Operating knowledge, the art, can be consistently employed to enhance regulatory control through the judicious application of an expert system. Using an expert system, a supervisory control routine was developed, and success- fully implemented, in the copper flotation circuit at Brenda Mines Ltd.The expert system ran in conjunction with regulatory PI controllers on a personal computer. The expert system received assays via an on-stream analyzer and adjusted regulatory loop set points as required in real-time. From its commissioning in November, 1989, to the end of the mine 's operation in June, 1990, it was enthusiastically embraced by the operators and attained operating levels superior to those achievable manually.IntroductionExpert system (ES) software springs from research into artificial intelligence and is currently making significant inroads into business and industry. ES proponents make many attractive claims; they are a means of capturing the knowledge of experts and they can be programmed by non-programmers. To date, most uses of this software in the process industry are in off-line applications, meaning that the applications are not tied directly to operating (on-line) environments. Moreover, in on-line environments, they are typically employed as advisors and only suggest changes. Human operators are required to close-the-loop to the process. Yet, an ES should be applicable to operating environments and, if the claims of the proponents are valid, should also be better than existing tools. As an intelligent controller an ES must use the knowledge of experienced operators, apply it directly to a process and do this without the intervention of human operators. On-line applications have been successfully employed in the closed loop control of SAG circuits (Herbst et al., 1989) and flotation circuits (Hales, 1989). Harris and Kosick (1988)detail an implementation for flotation control at the Polaris Mine."

Jan 1, 1992

By D. Krippner, C. Nexhip, D. George-Kennedy, P. Gebski, R. Kaur, W. L. Ying

ABSTRACT Water-Cooled Tapblocks Are Essential Components Of Modern Smelting Furnaces. Uninterrupted Operation Of A Tapblock Is Critical For The Optimal Operation Of A Furnace. This Critical Function, Together With Exposure To Extreme Conditions, Drives The Need For An Efficient And Reliable Means For Tapblock Monitoring. The Main Objective Of Tapblock Monitoring Is To Help Optimize The Life Of The Tapblocks By Better Scheduling Inner Refractory Relining And Protecting Operators By Preventing Sudden Deterioration Of The Tapblock. A Taphole Acoustic Monitoring (TAM) System Was Developed To Meet The Above Requirements. This Paper Describes The Principles Of The TAM System And Selected Case Studies.

Jan 1, 2013

By R. Simon, A. Khosravi

"Tensile strength of rock samples is measured by direct and indirect tensile tests in accordance with standard guidelines. Due to the difficulties in performing direct tensile test, the indirect tensile (Brazilian) test is conventionally carried out to obtain the ultimate tensile strength. A limited number of studies have been conducted to investigate the role of sample size (length to diameter ratio = L/D) in the stress distribution of the Brazilian test using numerical and analytical methods. These investigations showed that the tensile stress distribution along the loading diameter is not uniform. They also indicated that the difference between the tensile stress at the middle part and at the sides of the sample with higher L/D ratio is greater than that in the other samples.The objective of this study is to show the effect of tensile stress distribution on the fracture surface created by the Brazilian test from a morphological point of view on the samples with different L/D ratio. Hence, a series of fracture surfaces created using the Brazilian tests on the rock samples with L/D of 0.5, 0.75, 1, 1.25 and 1.5 were investigated.In this study, all fracture surfaces were scanned by a 3D laser profilommeter. A number of roughness profiles parallel and perpendicular to loading axis have been selected from the samples with different L/D ratio and spacing of 1 mm. The results show that the roughness of the profiles perpendicular to the loading axis increases with an increase of L/D ratio, while the roughness of the profiles parallel to the loading axis decreases. Furthermore, some roughness profiles parallel to the loading axis were chosen and divided into three segments. The results revealed that the segment in adjacent to the upper loading platen possesses higher roughness than the other segments."

Jan 1, 2015

By R. R. Tatiya

"The ultimate aim of a mine design is to determine the development work involved and resources required by adopting one or more specific alternatives. A part of the process is the production of mining plans/designs, an outline of the amount of work and costs involved as well as a prediction of the revenues expected. The paper aims to examine these aspects of mine design using the computer models developed. These models are capable of designing and performing economic analysis for one or more stopes for a continuous orebody. IntroductionTatiya and Allen (1987) have described ’defining stope boundaries using a computer.’ Using the stope boundaries defined or even hypothetical ones, algorithms have been prepared to design the layouts of the following stoping methods: 1. sublevel stoping (longitudinal as well as transverse);2. DTH (Down-the-hole) stoping; and3. flat back cut and fill stoping with posts and pillars.Tatiya (1989) presented this work at the 21st symposium on the application of computers and operations research in the mineral industry (APCOM). Economic analysis of a stope is the additional feature incorporated with these algorithms.The system has been tested by an economic analysis of the three stoping methods modeled for a small portion of a deposit of a copper mining complex. The deposits at this mining complex form lenses of varying shapes and sizes, having low copper content. These chalcopyrite lenses are steeply inclined with a thickness in the range of 5 m to 60 m. The strata are competent and suitable for underground mining.In different sections of the mines different sets of equipment are used to perform the basic unit operations. Some of the ore handling levels in the mines are trackless, the rest are tracked."

Jan 1, 1998

By Guangyuan Li

A 3-D block-spring model (BSM) has been developed for simulating the behaviour of jointed rocks. The model uses a discontinuous formulation and an iterative procedure to solve the large displacements in jointed and faulted rock masses. The 3-D BSM has been used to simulate mining excavations in jointed rocks around an open pit and underground settings. The applications have demonstrated that it is a practical tool to solve complicated problems of rock mechanics in civil and mining engineering. This model has recently been modified to incorporate complex geological conditions, such as underground water flow (seepage), unstable blocks and the time-dependent behavior of backfill materials. To demonstrate the capability of the 3-D model this paper presents the fundamentals of the 3- D BSM and its application for open-pit mining. A complete computer package BSM3D has been developed based on the 3-D block-spring model. The package consists of a solving engine for numerical analysis and a Windows based processor for mesh generation and results display. The multi-functioned pre-processor provides tools and menus to help users setting up models easily and conveniently. The fully featured post-processor allows users to view the results in different windows and orientations. The graphical results include contours, vectors, animation of rock movement, and the failure state of the rock structures.

May 1, 2001

By James Mackie

The Vancouver Stock Exchange (VSE) has been providing venture capital for start-up companies since 1907. Ninety years' experience in the junior mining industry has enabled the VSE to develop policies and procedures tailored to the unique needs of start-up companies. Policies and procedures applicable to listed companies are documented in the Corporate Finance Services Department "Policy and Procedures Manual." Approximately 50% of the companies listed on the VSE are in the mineral exploration and development business. The largest number are exploring base metal, precious metal or diamond properties. A recent count shows that about 20 companies are exploring industrial mineral or non-metallic deposits. The minerals sought by these companies include limestone, decorative stone, building stone, lava rock, wollastonite, zeolite, garnet and graphite. There are two basic routes to obtaining VSE financing for an industrial mineral property. The owner can either sell an interest in the property to a listed company or form a company and have it listed on the VSE. In each instance, the listed company is responsible for raising funds to develop the property. A typical financing consists of the sale of company securities byway ofeitherprivate placement or prospectus offering.

Jan 1, 2001

By B. W. Clyburn

"Coals from the Corporation's Lingan and No. 26 mines are classified as high-volatile A bituminous, with a very low inherent ash and containing a/l essential properties to provide metallurgical coal, with the exception of a high sulphur content. Only through proper cleaning at low specific gravity can the pyritic sulphur fraction of the coal be liberated to an extent where final sulphur meets coking standards. This first section of the paper deals with the operation of a Dutch State Mines heavy-media cyclone circuit to achieve an actual separation in the region of 1.30 specific gravity. A discussion of the parameter of control which must be applied along with an appraisal of the results obtained is included in the paper.IntroductionVery high fluidity and unusually low ash are the outstanding characteristics of coal from Devco's mines in the Harbour seam of the Sydney coal field.However, sulphur content, mainly pyritic, ranges from 1 to 2.5070. To obtain the low and consistent sulphur level required in metallurgical coking coals, preparation at low specific gravity is required .Metallurgical coke is used as the fuel in an iron blast furnace. Its sulphur content largely determines the quantity of slag required to remove it and therefore influences furnace productivity and unit costs.Typical data on the various coal properties of importance in the production of coke are included in Table I. Necessity of Low-Gravity SeparationThe design of any coal preparation plant requires the study of washability properties of the coal to be treated to determine the quantity and quality of coal produced at a given specific gravity along with the difficulty in accomplishing that separation.Their low ash content allows the important washability aspects of Harbour seam coals to be represented by sulphur! specific gravity curves (Fig. I). This particular example indicates that a yield of 54.5% is attained, at a sulphur content of 1.20%, for a perfect separating device operating with a 1.29 S.G. cut point.Material rejected from this separation still contains usable coal, which is recovered as middlings by separating at a higher gravity."

Jan 1, 1980

By Linda Dufour

"Autoclaves have been in commercial use in the mining industry since the early 1950's the initial applications included tin, uranium, cobalt, nickel and copper extraction under both acidic and alkaline conditions. These circuits varied in batch or continuous operation. The geometry has been spherical, vertical, and horizontal type with up to six agitators, with throughput as high as 1000 stpd.Presently autoclaves are a good process selection for many refractory sulphide gold bearing ores. The first application of pressure oxidation in the gold industry was at the Homestake Mcglaughlin's Mine which was commissioned in 1985. This was an acidic pressure oxidation process treating 3000 stpd in three four compartment horizontal autoclaves 14' diameter and 53' long. Since the initiation of autoclaves for the treatment of gold bearing sulphides, there are presently 16 gold autoclaves operating worldwide varying in size up to 18'4"" inside diameter. There are seven autoclaves for the treatment of refractory sulphide gold bearing ores to be commissioned in 1997 and 1998.Autoclave technology has progressed extensively since the mid-eighties. Operational experience has made rapid progress and the result is much smoother and safer autoclave operation. There have been many advances in autoclave technology design. For example, the use of exotic materials for corrosion resistance to reduce down time for maintenance. The instrumentation involved in autoclave operation is very sophisticated which allows for many safety features. The advanced design has allowed for greater availability and as a result operating costs and maintenance costs have decreased. These technological advancements have made autoclave technology more safe and this has resulted in a greater acceptance of this type of operation. Many of the gold autoclave facilities operate up to 9 months continuously without shutdowns. The advancement of autoclave technology has inspired many new applications.Because of the outstanding operation of autoclaves in the gold industry, many other applications for autoclave technology are being considered. The following is a list of autoclave applications:"

Jan 1, 1997

By Nicola Robjohns, Kenneth A. Grace, Jane Spooner

"The important volume end use sectors for the rare earth elements and yttrium continue to be in steelmaking, petroleum cracking catalysts and glass polishing. The market sectors which may provide future high volume demand, to replace the older sectors where demand has declined over the past decade, include magnets, automobile catalysts, ceramics and superconductors. Increases in production capacity in all major rare earth producing countries are expected to restrain large price increases for high purity rare earth oxides over the short term. A sharp increase in demand for yttrium in advanced ceramics and superconductors would lead to a shortage in separation capacity, however, and to a corresponding rise in prices for separated rare earths.IntroductionWhile visiting the Geology Department of the University of Toronto in 1981, Professor Lu from the Institute of Geochemistry of Academia Sinica at Gweiyang in China introduced one of his seminars with the observation that in China, rare earths are not rare at all.Indeed, while being rare in terms of abundance as measured by, say, the Clarke scale, the rare earth elements, like many other low abundance elements, are subject to geological, geochemical and mineralogical concentration.The rare earth elements comprise the fifteen inner transition elements of Group IIIB, Period 6, of the periodic table, from lanthanum to lutetium (the lanthanides), as set out in Table 1. The rare earths constitute a distinct group as they have extremely similar chemical characteristics due to the uniformity of their outer electron shells. The element yttrium is usually, by convention, included in the rare earth group as it occurs with the rare earths in nature and has properties very similar to them.The rare earths are divided into two subgroups, the ""light"" rare earths, made up of the first seven elements of the series, lanthanum to europium, and the ""heavy"" rare earths, comprising the remaining eight elements, gadolinium to lutetium, plus yttrium. These two subgroups are also referred to as the cerium subgroup and the yttrium subgroup, respectively. The subdivision is based on differences in the atomic radii resulting in somewhat different properties for the two subgroups."

Jan 1, 1991

By Y. Guglielmi, C. Gout, P. Henry, P. Dick

The key questions about fault reactivation in shales concern the potential enhanced fluid displacement through a previously low-permeability aseismic shale formation. Here we selected a critically-stressed fault cross-cutting the underground research facility of Tournemire (France) which is located in Toarcian shales. Several inclined boreholes were drilled across the 8.5 m thick fault zone characterized by a fractured damage zone (FDZ) and a central 2.4 m thick complex core (FC) made of multiple shear bands with gouge intercalated with highly fractured lenses. The fault was pressurized using a straddle packer system defining a 2.4m long injection chamber normal to the fault surface. Three fault zone intervals were tested, two in the fault damage zone and one in the fault core. A three-dimensional displacement sensor set in the chamber allowed continuous synchronous coupled monitoring of fault movements, injection pressure and flow rate. An anticlockwise 0.22-to-0.05 mm fault slip was captured associated with a 10-to-100 hydraulic aperture increase of the fault. Preliminary analyses of the experiments show that leakage in the fault zone is controlled by strength and stress magnitude contrasts between the fault core and the fault damage zone. Fault damage zone discontinuities display a much higher peak static friction angle than the fault core shear zones, respectively of 34 and 22° that could be related to complex interactions between healing and sealing processes. Fault core leakage is much more dependent on strain than on effective stress variations. Discontinuous, pulse-like leakage, develops following complex failure processes that may simultaneously take place in the gouge zones and along the large pre-existing discontinuities. Such results may be of importance in evaluating fault seal integrity in oil and gas exploration, production or CO2 storage or underground excavations monitoring.

Jan 1, 2015

By William Shaw

Conditional simulation is now an accepted tool for managing ore block design at a number of operating mines. It provides a way to consider the quality of data, local continuity and economic risk in defining ore and waste across the cut-off boundary. In addition a computer based system can ensure consistency in making decisions to meet multiple criteria such as cut-off grades, minimum ore-block size and contaminant grade limits. The development of a procedure for using multiple criteria allows ore blocks to be defined using alternative strategies depending on the specific production requirements. This has introduced the opportunity to define ore blocks for different destinations based on their material types and opens the way for geometallurgical modelling to be incorporated into grade control.

Oct 1, 2009

By J. Ran

"Hangingwall sloughing is the major cause of unplanned stope dilution in open stope mining. Understanding the hangingwall sloughing mechanism can guide the stope design in minimizing the unplanned dilution and improving muck size and therefore mining efficiency. Though the modified stability graph method may be adopted to assess the hangingwall stability, for mines where the hangingwall is inaccessible, the required parameters are difficult to define and some of the simple influential factors cannot be easily identified in this method to provide guidelines for stope design.This paper identifies the main modes of hangingwall sloughing in open stope mining based on detailed data collected from mined-out stopes and site observations, applies the voussoir beam notation to analysis of the hangingwall sloughing mechanism, compares the model analysis results with the collected stope data, and provides guidelines for stope design and model application. Finally, examples are given to demonstrate the time and support effects on hangingwall sloughing and stope dilution."

Jan 1, 2002

By Louis M. Perlman

CAN PRESENT TRENDS CONTINUE? Can population growth in the world keep going at the average rates of the last few decades, till, say, the year 2000? And beyond? At the same time, can we expect steady increases in mineral consumption per head, all over the world, as the living standards of many nations converge toward the living standards of North America? If they do converge? Does the total fund of world resources extend, with foreseeable techniques, to supplying the consequent demands for metals, non-metallic minerals and energy? Do we have the requisite economic and scientific techniques available to answer these questions? Certainly, we cannot forecast over decades with any certainty. There are many, of course, who seem to believe that by the simple fitting of trends, they can tell us something about the world and resource constraints in the year 2000, twenty-three years from now. It is significant that many studies of this sort have added sustenance to the 'doom-watching' fraternity of commentators. The reason is simple. The extrapolation of exponential trends into the distant future frequently leads to the most astounding and impossible scenarios. Another feature of exponential growth is the suddenness with which certain fixed limits are approached. It took world population two hundreds years to increase by 1/2 a billion, from 1650 to 1850. Yet some U.N. estimates suggest that the net addition to human population will be over 2 billion between now and the end of the century. Thus, the present world population would increase from a little under four thousand million today to rather over six thousand million in the year 2000.

Jan 1, 1977

By R. S. McCaffrey

In addition to its importance in agricultural production, Wisconsin is a very large manufacturing state and its rank in the metal working industries is probably first among the States of the Union per unit of population. The University of Wisconsin is a state supported institution and the Wisconsin tradition has always emphasized the relation of the University to the state and its responsibility to exercise its leader-ship where it might, in any and every way, for the development and benefit of the state and the community. The Department of Metallurgy of the University realized its responsibilities in the carrying out of the co-operative tradition and, two' years ago, an experiment was started in co-operative research between the University and certain of the industrial plants of the state. At the present time this work has so far progressed that it is no longer an experiment, and its results prove that this co-operative research may be carried on very advantageously and that, under the conditions existing in the state, the method employed has been satisfactory.

Jan 1, 1926