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By A. Bouajila

To stay competitive in an open market, mineral industries have to optimise their processes, lower their production costs and improve the commercial value of their products. Up to a recent past, they were impaired in this attempt by a lack of adequate devices allowing reliable on-line and real-time process monitoring (detection or measurement). Process monitoring for process control and the product characterisation for quality control are quite different tasks. Planners and researchers should be fully aware of this when evaluating or developing monitoring equipment for on-line process control. This paper will comment on some aspects of sensor specifications, during the design and the evaluation steps, related to sampling, measurement (accuracy, sensitivity, delay and correlation to the process) and suitability to the exploitation environment. Examples of R&D projects promoted by COREM for various industrial applications will be presented.

May 1, 2001

By Hao Zhang

Site inspection is an important component of safety management system. In current practices, the inspectors evaluate the safety condition on a construction site with the assistance of a standardised checklist. However, the checklist emphasizes on evaluating the implementation of safety management system, but provides limited task-specific check items for assessing whether the individual construction tasks are conducted under safe condition and in a safe manner. To address this issue, the research presented in this paper aims to provide safety practitioners with comprehensive and taskspecific safety information to promote effective risk identification and facilitate strategic risk control during site inspection. Specifically, this research first builds a project-specific safety information database, which stores potential risks and control measures for each construction task. The research team then develops a mobile decision support tool to retrieve information from the database and support safer decision-making on site. The tool supports users in two ways: one is to provide daily risk checklists and risk control strategies to guide step-by-step inspection alongside the project schedule; the other is to let users input any safety-related keywords during the safety inspection process and the tool returns relevant safety information by applying text mining algorithms. It is ongoing research. This paper presents an overall research framework and discusses the progress in developing safety database and data retrieval concepts. The outcome of the project will help enhance safety management practices and reduce possible risky working conditions on a construction site.

Aug 1, 2013

By B. L. Moreau

Certain gas wells tend to form hydrates in the production tubing. This paper outlines a method developed and used by the Author's company to overcome the problem. The injection of glycol to control hydrates results in sufficient dehydration to allow the gas to be trans-ported through a field-gathering system b a treatment plant. Sub-surface injection of glycol also offers a method of introducing corrosion inhibitors into the gas stream. The major operating difficulties have been overcome and the system is now in use in the northeastern part of British Columbia.

Jan 1, 1958

By D. Groenveld, M. Rozou

"Recent trends move towards automation, smart sensors, internet of things, powerful DCS, and more data. Are those trends already utilized in a real time production environment? Today operators still have to monitor several complex processes at the same time and predict their behavior based on an overwhelming amount of data available.The fact of the operator being overloaded and humans being unable to process multivariable problems shows the need of a tool merging essential data and providing consistent, sound decisions for long-term profitability.This paper shows a successful execution of ABB’s process improvement services in Aitik (Boliden SA), a copper mine located in Sweden. Soft sensors, fuzzy rule blocks and model predictive control were seamlessly integrated in the control system of the grinding area, resulting in proper control of mill loads and particle size without violation of any constraints.INTRODUCTIONDepending on the ore characteristics and the targeted plant capacity, the design of the grinding circuit may vary significantly. Typically, the circuit consists of several mills (rod, ball, SAG, AG) in series and/or parallel with a number of classifiers and sumps at appropriate locations. The goal of the grinding section is to reduce the ore particle size to a level that enables efficient separation between gangue and precious metals in the subsiding processing step. The trade-off between quality and quantity has to be made. It is also crucial to execute this process step at the lowest possible energy and grinding media consumption.An optimal grinding process controller must manage to maintain a given fresh feed level while keeping the product size within a given range without violating any constraints such as power, torque or load limits. To accomplish the aforementioned, it is necessary to manipulate the ore feed rate, water feed rate and the mill speed. The most significant disturbances adding another degree of complexity to this control problem are ore hardness and the amount of circulating load."

Jan 1, 2016

By D. J. Scarpato

"Slope construction in shale can present some interesting challenges for geotechnical design engineers and contractors alike. There are challenges that can be expected and designed-for; however, all too frequently, such challenges manifest themselves as “surprises” in the field. Common constructability challenges can include those such as drill hole deviation during drilling for controlled blasting; and, excavation slope instability arising from inconsistent perimeter control drilling. Drill hole deviation results from the cumulative effects from both drilling mechanics and rock mass conditions. Once a hole has initiated the deviation trajectory, it is difficult to rectify drill steel position. Although such challenges are not necessarily unique to shale, they are often exacerbated by weak, weathered and transversely isotropic nature of bedrock conditions. All too often, the working assumption is that shale is “soft” and easily excavatable; however, this blanket assumption can prove to be costly. This paper is intended to provide design professionals and contractors with the practical considerations needed to avoid the “surprises” associated with drill hole deviation, and minimize the potential for costly claims.INTRODUCTIONFor all the slopes that have been excavated worldwide, and for such advancements in excavation technology and field characterization, one might be tempted to believe that the industry almost has slope development down to a science. This is frequently not the case, especially for weak/weathered and anisotropic bedrock. Excavation contractors are still pushed to the limits of what their technology can achieve, and engineers are all too often called to the field during construction, to make potentially risky onthe- fly decisions relative to excavatability, short and long-term slope stability, and project safety. Although there have been a host of other research papers and journal articles that have been written on the subject of deviation over the past 30 years (Brown, Geen, Sinha, 1981), the problems associated with drill hole deviation are still all too frequent. This fact is especially true for civil engineering surface excavations in bedrock."

Jan 1, 2015

By Kevin C. Milne

"The solution of problems associated with development of a sour gas reserve will be of increasing importance in tl1e next few years if gas export is approved •by the National Energy Board. The purpose of this paper is to review briefly the history of the Carstairs gas field, and tCI describe in a general manner the reservoir, and the producing and processing facilities.HISTORYThe Carstairs gas field was discovered in April 1958 when the discovery well, Home Carstairs 10-17, was successfully completed as a gas well in the Elkton member of the Turner Valley formation. Geo-graphic location of the field is shown in Figure No. 1. Note that the field is about five miles west of the town of Carstairs, Alberta, which in turn is about 40 miles north of Calgary. Drilling subsequent to the discovery well resulted in three addition-al producing wells and one dry hole during I.958; two producing wells during 1959; and one producing well and one dry hole during 1960. Thus, seven producing wells and two dry holes have been drilled in the Carstairs field to date.In November 1959 a 12-section block in the Carstairs field was unitized on a surface acre basis. Mean-while, in June 1959, operators in the field executed an ""Interim Plant Agreement"" that provided the money needed to start construction of a joint venture processing plant and gathering system. Construction of the plant and gathering system was completed in February 1960."

Jan 1, 1960

By Loui Geoffroy, Philippe Gaultier, Martin Piotte, Claude Coache, André Drouin

"Automatic driving at high speed of an underground truck was tested at Brunswick mine in September 1995. Modifications to the truck included: a remote interface to control actuators, front and back video cameras to follow a roof mounted optical guide and proportional hydraulic controls on the steering.The mathematical model of the hydraulic system was adjusted using least square regression. The steering data, used in calculating the regression parameters, were acquired from the moving truck. The automatic steering control used three measured variables: lateral deviation, angular deviation and steering angle. Lateral deviations are obtained using the cameras, which are in continuous view of the guide, while steering angles are acquired from an extensiometer placed at the articulation point of the vehicle. Gain scheduling was used to compensate for vehicle speed and available hydraulic flow. Non-linear characteristics of the modeled hydraulic system were offset using open loop compensation.Speeds up to 23 km/h in forward direction and 13 km/h in reverse were achieved deviaduring continuous testing along one of the mine’s production drifts. Proportional steering was essential in achieving high speeds, as it enabled more precise positioning of the vehicle’s steering direction while reducing the abuses on cylinder and cylinder pins via diminished oscillations about the optical guide at high speeds."

Jan 1, 1997

By M. Bigdeli Karimi

In this study, the effect of strain level and holding time in semisolid temperature range via SIMA process on AS21 Mg alloy was investigated. Some cylindrical samples of this alloy with 1cm in height and 2.5cm in diameter (H/D=0.4) were compressed to 10%, 20%, 30% and 40% at 300-C. Then, the samples were reheated in semisolid temperature range at 614°C for various times. The results of optical microscopy and image analysis showed that with increasing of strain and holding time, dendritic structure changed to equi-axed structure, gradually. Also, the best conditions to obtain good globular structure were achieved. Furthermore, it was seen that after compression and reheating, Mg2Si intermetallics with Chinese script morphology converted to dispersed-fine particles which were distributed into the ci-Mg grains.

Jan 1, 2007

By Micheal Mayhew

"This presentation will provide information and facts on the drilling and blasting within a frozen shaft using a full face methodology. The Author will briefly discuss the history of the sinking of a frozen shaft in Saskatchewan, the challenges faced, and the solutions delivered. The case study will include a discussion describing the series of events that led to the decision to adopt a full face blasting methodology. The case study will describe key elements such as the drilling pattern, hole size and depth, explosive products and blast vibration monitoring systems. INTRODUCTION During the shaft sinking process at a project in Saskatchewan, it was recommended that a drill & blast benching method be utilized. Following an evaluation of the site, the geological conditions proved amenable to a ground freezing system that would stabilize the rock formations and prevent inflows of water into the shaft (Table 1).The shaft sinking process required that the ground surrounding the proposed shaft be frozen by drilling several near vertical freeze holes radially at a specified distance from the edge of the proposed shaft excavation. This would allow for the circulation of a chilled brine solution down the freeze holes. The circulation is achieved by means of stainless steel pipes encased within each other to provide a delivery and return conduit for the brine (Figure 1). As a result of this periphery freezing, the ground within the shaft excavation is also predominately frozen.The finished internal diameter of the shaft was 5.5 meters with varying overall excavation diameters to facilitate different liner designs used for various rock formations. For the most part, the fully unsupported/unfinished excavated diameter of the shaft varied from 6.9 meters to 8.5 meters depending on the zone excavated. The challenge was that the proposed drill and blast excavation method posed a significant risk due to the potential to damage the freeze wall and pipes during blasting. The decision was made to commence the excavation through mechanical excavation (i.e. chip and cut) methods then change to a drill and blast method utilizing a split benching design. Through this process, the team encountered five main challenges: 1. Sub-horizontal geological structures and slips that affected blasting performance and sometimes resulted in a sloping surface to the top of the bench; 2. Confined working area for the crews and equipment due to a limited work area as a result of utilizing the split (half) bench drill and blast methodology; 3. Mechanical chipping and cutting of the one-meter buffer zone to the final shaft diameter; 4. Crews working on extremely slippery uneven frozen rock and ice surfaces, which affected safety and efficiency; 5. Establishing a blast vibration monitoring system to determine if the drilling and blasting of the full shaft excavation diameter were acceptable."

Jan 1, 2019

By P. Cavanagh

Summary This paper discusses the fundamental principles which allow the development of a new method for studying the deformation and failure of metals in terms of 'internal microstrains'. Internal microstrains mechanical and magnetic properties are defined and their influence on of metals is outlined. A research programme at present in progress will determine whether magnetic measurements of internal microstrains give sufficiently accurate values for predicting the performance of metals under service conditions. These magnetic test techniques are also being used to detect the beginning of plastic deformation and to trace the development of deformation processes and failure. Results of the experimental work in each field will be published. Introduction Any attempts are being made to develop a complete theory embracing the mechanical behaviour of metals. In spite of the amount of experimental data available, the theoretical approach is rather difficult, since most of the mechanical properties of a metal are determined by deviations from the pure chemical composition or the perfect crystal. Both types of deviation are difficult to reproduce experimentally and to describe theoretically. In general, there are three main avenues of approach to the problem being followed today.

Jan 1, 1950

By A. Golabchi

Building Information Modeling (BIM) is an increasingly popular method for generating and managing facility information during the life cycle of a building, ranging from facility conceptualization, through design, construction and its operational life. Organizations involved in Facility Management (FM) have the opportunity to use BIM as a knowledge repository to document evolving facility information and to support decisions made by the facility managers during the operational life of a facility. This paper demonstrates the potential of using BIM to develop algorithms that automate decision making for FM applications. The potential of utilizing BIM as an analysis tool is demonstrated through the scenario of HVAC (Heating, Ventilation, and Air Conditioning) system failure in an operating facility. In case of a typical HVAC malfunction today, facility occupants record complaints in a ticketing database maintained by the FM organization. Upon receiving notification of HVAC system failure, facility inspectors visit the location to confirm the reported failure. Upon confirmation, facility managers review building plans and specifications to develop a detailed plan of action to repair any HVAC components suspected of damage. Based on the plan of action, inspectors visit the facility to inspect and, in case of damage, repair the appropriate HVAC system components. These FM practices ? as currently implemented across the industry ? are labor intensive, time consuming, and often rely on unreliable and outdated information. To address these shortcomings, the authors propose an alternative methodology of HVAC fault detection in operational buildings. The authors implement an algorithm that leverages complaint ticket data and automates BIM to determine potentially damaged HVAC system components. Based on the list of HVAC components suspected of damage, the algorithm develops a plan of action for the facility inspectors. Finally, the authors discuss the advantages of the proposed method as well as the challenges of implementing automated BIM-enabled decision making processes in the FM industry.

Aug 1, 2013

By M. A. Power

The diamondiferous Drybones Bay kimberlite pipe is the largest pipe (900 m by 400 m) discovered to date in the Northwest Territories. The pipe intrudes granodiorite of the Archean age Defeat Pluton and contains crater, reworked crater (epiclastic) and diatreme facies kimberlite. In-situ measurements of seismic p-wave velocity were recorded with in-line refraction arrays over representative areas. Refractions from fresh kimberlite were recorded over epiclastic facies kimberlite in the eastern portion of the pipe and returned an average velocity of 4300 m/s. Refractions from weathered kimberlite were recorded on all lines and returned velocities ranging from 1900 m/s to 2200 m/s. Granite surrounding the pipe returned an average velocity of 5400 m/s. The results indicate that there is a definite contrast in seismic velocities between kimberlite and country rocks at Drybones Bay and suggest that seismic refraction surveys may be an effective means of screening kimberlite targets in glaciated areas underlain by igneous or metamorphic rocks.

Jan 1, 1998

By L. Van Wyk, J. Fernandez, J. Suarez, L. J. Diaz, A. Uria, D. Breeuwer

"Ventilation is an essential component of any underground mine, playing a vital role in ensuring the health and safety of workers, and a mine’s continuous operation. At a time when mining companies are increasingly having to move to deeper underground operations in pursuit of high-grade ore-bodies, the search is on for more efficient ventilation systems that will allow mining to be carried out at even deeper levels whilst ensuring the protection of workers and the maximisation of productivity through temperature management and the lowering of energy costs. Mining companies today are looking for innovative ways to deliver new technologies and procedures to enhance their mine’s profitability. Energy consumption by mine ventilation systems is higher than ever due to stringent specifications of underground equipment (primarily combustion engine emissions), air quality standards and mining at deeper levels which all require more powerful ventilation systems. With energy costs associated with operating ventilation systems being a mine’s second-highest cost of production after labour, finding the optimal ventilation solution is critical to a mine’s performance. Proper fan design remains a major factor in reducing capital expenditures (CAPEX) and operational expenditures (OPEX), which means that there are compelling reasons for making use of comprehensive factory testing at full power before fans are dispatched to site to simulate the mine’s current and future design requirements, and thus verify the fan’s effectiveness in ‘real’ conditions.INTRODUCTION A primary mine fan is considered the heartbeat of the entire mine ventilation system, drawing fresh air from the surface and providing a safe environment for miners. A ventilation system’s lack of performance often leads to a reduction in acceptable air quality levels for underground working operations and can potentially have an adverse impact on production rates."

Jan 1, 2019

By Wilson Pascheto

One of the main outcomes of a capital project is the reliability of a new plant, system or equipment. During 20 years of experience working in various capital projects for the mining industry, the author experienced failures which have caused significant losses to Owners, in many cases amounting to millions of dollars and almost jeopardizing entire projects. Often, failures were related to faulty design, shop fabrication and/or construction. Therefore, significant opportunities exist in the Mining Industry to improve the success rate of capital projects, improve on-line time at start-up, minimize the occurrence of unplanned maintenance due to equipment failures, and all this with positive contribution to health and safety. This paper presents some examples of failures and how they could have been prevented by proper Quality Assurance methodology. It also discusses some of the main challenges in the implementation of such methodology, including awareness of the Materials discipline and availability of trained Engineers.

Jan 1, 2015

By W. Grell

"In this paper, two methods of standardizing mill language are proposed; one is based on metric units and the other on English units. Tentative procedures for chemical and screen analysis based on published methods are proposed.Standard procedures for determining work index, and for leaching, flotation, and classification tests are outlined.Objects of Standardization:(1) to improve communication -(a) among gold metallurgists(b) with other branches of mineral dressing(c) with mineral dressing in other countries(d) with general scientific procedure(2) to improve mill control by -(a) standard methods of analysis (i)(ii)(iii)(b) standard methods of calcula tiort(c) standard accounting proceduresin the plantin the mill laboratoryin the assay office(3) to improve mill test work and investigationAreas of Standardization(1) Nomenclature or terminology(2) Measuring techniques(3) Test procedures(4) Accounting procedures"

Jan 1, 1966

By S. Kamado

Development of new SF6 alternative cover gas with low global warming potential is strongly desired for melting and casting of magnesium alloys. We have tried to apply several kinds of HFC and HFE gases with low potential from 30 to 950 as protection gases to AZ91D alloy melt in the temperature range of 650 to 800°C. As a result, protective film consisted of MgF2 and MgO is formed on the melt surface and ignition-proof effect is sufficiently obtained at all the temperature ranges even when flow rates of mixed gases containing CO2 as a carrier gas are almost the same as those using SF6 gas. Reduction of global warming potential exceeds 98% at 650°C and 89% at 800°C in comparison with a mixed gas of CO2 and SF6.

Jan 1, 2006

During industrial copper electrowinning, a fraction of the electrolyte becomes entrained with the oxygen gas bubbles that are evolved at the anodes. The fraction of entrained bubbles increases from the bottom of the anode to the top, resulting in a bubble distribution that appears as an inverted wedge between the cathode and anode. Since the bubbles act as insulating spheres, electrolyte resistance increases from the bottom of the electrodes to the top resulting in correspondingly higher local current densities and uneven copper growth along the cathode. To counter-act the inherent tendency toward excessive copper growth near the bottom of the cathodes, the use of tapered anodes was examined. The potential improvement in cathode current distribution was evaluated by comparing the primary current distributions for 2-D computer models of a copper electrowinning cell with plate shaped anodes against one with tapered anodes.

Jan 1, 2007

By H. B. Lumsden

This paper is intended to deal merely with the commercial development of some of the principal non-metallic mineral resources in the three prairie provinces- Manitoba, Saskatchewan, and Alberta. Coal is not included in this summary. Building Stone First and foremost, mention may be made of the building stone now being produced at Tyndall, Manitoba. This is a mottled limestone and is declared by experts to be one of the finest building stones in America, both as regards durability and appearance. It has been used very extensively both for exterior and interior work, not only in western Canada, but also in the principal cities as far east as Montreal. The stone is the "'Upper Mottled Limestone", which forms the summit of the Trenton (Ordovician) strata in the Lake Winnipeg basin. Quarries are at present being operated at Garson and Tyndall . The area where this stone is known to be available extends in a north and south direction for a distance of three miles, and the main productive ridge is probably about one half mile wide. The outlook for the future of the industry is extremely promising, as the stone is becoming increasingly popular in Eastern Canada, more particularly for interior work.

Jan 1, 1928

By J. Güntner

A significant portion of Outotec's business relates to the application of fluidized bed for processing a wide range of industrial materials, including gold ore and gold concentrate. As part of the former Lurgi and Boliden organization, our division constructed the first industrial reactor for roasting sulphur-bearing materials in 1950, based on the principles of fluidized bed technology. This process, when combined with efficient heat recovery and off-gas treatment and its conversion to sulphuric acid, became the standard for processing sulphur-bearing ores. In the last 60 years we have delivered more than 265 plants and developed (in addition to the standard fluidized bed solution) variants of the fluidization technology, such as the circulating fluidized bed and the bubbling fluidized bed. This paper describes the different options of the fluidized bed technology for gold roasting reflecting on main process design criteria.

Jan 1, 2011

By M. D. Griffith

"Ventilation models are a vital tool to ensure ventilation designs can provide airflow to all work areas in a mine. Airway resistance and variations in natural ventilation pressures will affect simulated airflow and heat distribution through a mine. Validating ventilation model resistances and pressures to the exact underground conditions can be difficult and the variances can contribute to significantly different simulation results depending on the structure of the ventilation design. The study will use sensitivity analysis to explore examples of variability of simulated airflow due to small resistance, heat and natural ventilation changes and thereby help the user identify both trustworthy and potentially unreliable parts of a mine ventilation model. INTRODUCTION Mine ventilation network modeling is a vital tool for ventilation professionals and has become increasingly relied upon during the design and operation phase of mine ventilation systems. However, they provide only an approximation of reality, and caution must always be exercised when drawing conclusions or making decisions based on simulated data. Ventilation modelling should be performed by persons with a sound fundamental knowledge of ventilation and ideally should be validated with field data, but in large mines, or mines which are yet to be mined, accurate input of the simulation variables can be difficult, and errors and inaccuracies may be difficult or impossible to avoid. This study discusses and investigates the sensitivity of the mine ventilation simulation results to input errors. In addition, there are limitations to what steady-state airflow and heat simulations can model, regardless of the accuracy of the model inputs. In some situations, steady-state solvers cannot capture the dynamic changing behavior of a ventilation system. This study will also describe and apply techniques to analyze the natural variability of mine conditions on ventilation models. The consequences of poor accuracy in some parts of a mine model may impact on the health and safety criteria of ventilation designs. For example, if an airway is required to flow in a particular direction and quantity, then despite a ventilation model showing correctly designed conditions, small errors in input values may result in incorrect prediction of the direction or quantity of airflow. This may create unexpected buildup of heat or gases during operational activities, causing safety issues or operational delays. The ability to know which parts of a mine ventilation model have increased potential for poor simulation results will allow engineers to consider the ventilation design and make changes if required to better guarantee the required design flows."

Jan 1, 2019