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By Dean S. Rogers

"In February 1980, Dome Mines Limited announced a $50 million expansion program which would result in a 50% increase in mill capacity from the present 1,815 tonnes per day to an eventual production rate of 2, 720 tonnes per day in the year 1984. As an integral and necessary part of this planned expansion, a new vertical production shaft, No. 8 Shaft, would be sunk from surface to a depth of 1,645 metres.Throughout the seventy-year history of mining at the Dome, gold has been found in a number of different rock types and in association with a number of different structural settings. However, the key to successfully locating ore deposits lies in the recognition of the favourable environments in which they generally occur. First and foremost, the exercise of locating the No. 8 shaft became an exercise in geological deduction based on the projection of these favourable lithologic environments.In November 1980, after detailed engineering work was completed, the total cost of the project was estimated at $75.5 million 1980 dollars or $91 million dollars allowing for inflation over a four-year construction period. These estimates include the shaft, significant replacement and alterations to the milling process, and an upgrading of the plant."

Jan 1, 1982

By Hani S. Mitri

Overhand cut-and-fill mining of narrow vein orebodies inevitably leads to the creation of horizontal pillars. As the thickness of the overlying crown pillar diminishes, stresses build up in the pillar. More often than not, this situation causes an increased level of seismicity and possible pillar burst. One well-known strategy to reduce the hazard of crown and sill pillar burst in cut-and-fill vein mining is that of destress blasting. The paper first reviews the methods used for the monitoring and assessment of potential pillar burst in narrow vein cut-and-fill mining. The influence of horizontal stress, mine depth and pillar thickness on stress build-up in the crown pillar is examined through a characteristic narrow vein numerical model. The paper then presents, with reference to three mine case studies, the benefits of destress blasting and the factors affecting its success as a ground control technique.

Oct 1, 2001

By J. S. Stachulak

"The main ventilation design features adopted at Inco to safeguard personnel against the effects of fires are described in this paper. Measures taken to prevent and detect fires due to spontaneous combustion, and fires involving conveyor belts, are described in detail.IntroductionConsidering the over-all picture of present-day mining operations, the expenditure required to provide a proper system of mine ventilation and fife control should be regarded as a sound investment that will pay back in increased mining efficiency, improved safety, health, and morale of the miners.Mine ventilation control and mine fife detection and fighting are inseparable, because a ventilation system can spread deadly products of combustion just as efficiently as it does life-sustaining oxygen. Therefore, the possibility of a mine fife occurring is of particular concern.The first objective is to prevent a fife.The second objective is to design the ventilation system so that a positive fresh air supply can be ensured on each main level regardless of the location of the fife.The third objective is to be able to detect the fife at an early stage and to extinguish it before it can develop into a major fife. Accordingly, at Inco, very extensive measures are taken to prevent fires and to locate, isolate and extinguish them rapidly. To obtain an early warning, it is not sufficient to know that a fife has started, but it is also necessary to know where the fife is burning."

Jan 1, 1994

By J. S. Stacbulak

"The main ventilation design features adopted at Inco to safeguard personnel against the effects of fires are described in this paper. Measures taken to prevent and detect fires due to spontaneous combustion, and fires involving conveyor belts, are described in detail.IntroductionConsidering the over-all picture of present-day mining operations, the expenditure required to provide a proper system of mine ventilation and fife control should be regarded as a sound investment that will pay back in increased mining efficiency, improved safety, health, and morale of the miners.Mine ventilation control and mine fife detection and fighting are inseparable, because a ventilation system can spread deadly products of combustion just as efficiently as it does life-sustaining oxygen. Therefore, the possibility of a mine fife occurring is of particular concern.The flirt objective is to prevent a fife. The second objective is to design the ventilation system so that a positive fresh air supply can be ensured on each main level regardless of the location of the fife. The third objective is to be able to detect the fife at an early stage and to extinguish it before it can develop into a major fife.Accordingly, at Inco, very extensive measures are taken to prevent fires and to locate, isolate and extinguish them rapidly. To obtain an early warning, it is not sufficient to know that a fife has started, but it is also necessary to know where the fife is burning."

Jan 1, 1994

By Andrew Dobson, Cheryl Allen, Enrique Acuña

"Totten Mine return air raise was designed with two parallel fans equipped with silencers to reduce the noise emitted from the outlets into the environment. As development and production of the mine progressed through the past years, the silencer system needed to be upgraded, and additional maintenance strategies have been necessary to meet the regulatory noise limits enforced by the province of Ontario. The current mine plan will require the fans to reach the upper limit of their capacity by Q1 2019. To achieve this operational target, additional silencing capability has been required and Totten Mine has explored alternatives to further extend the noise silencing capacity available considering the current constraints at the mine site. The alternatives included a new silencer baffle design and a new layout that have allowed doubling the length of the silencer system. Using acoustic measurement data collected on several occasions, this paper presents and discusses the performance of the various silencing systems which have been installed on the return air fans at Totten Mine.INTRODUCTION Vale Canada Limited’s Totten Mine is a base metal, underground mine extracting nickel and copper, situated in the Sudbury Basin of Ontario. The mine initiated operations at the end of 2013, and is equipped with two main return air fans and two main fresh air fans located on surface. Both fresh air and return air fans are set in a parallel arrangement to operate as integrated units and are equipped with variable frequency drives (VFDs) to allow for the remote modification of their operating set point, usually between 600 to 880 rpm, depending on the mine’s requirements. The main return air raise (RAR) fans are also equipped with dissipative baffle silencers to attenuate the noise emitted to the environment. Approximately four years ago, acoustical measurements conducted to verify compliance with the applicable regulatory criteria, and respond to noise concerns from neighboring residents, concluded that the sound emissions of the main return air raise exceeded the noise design parameters. The acoustic tones of the fans were audible offsite, at a residential location, approximately 9 km northeast of the mine site. The elevated sound levels and offsite audibility was due to degradation of the original discharge silencers from moisture and particulate being drawn from underground workings and passing through the silencer baffles. The audibility was also due to an outlet directivity pattern which directed noise towards the residential location."

Jan 1, 2019

By Nicholas C. Williams

This paper presents the development of a demand reduction and responsive strategy capable of reducing the electrical power demand, particularly during peak conditions. The work presented includes a case study of a UK colliery. Areas explained are the equipment installation at the mine; the development of the demand reduction strategy including the load profile database and prediction optimisation model. Some live production data from the power meter installation at the mine is also presented.

Aug 1, 2013

By Moatassem Abdallah

Buildings in the United States account for 72% of electricity consumption, 40% of energy consumption, 13% of water consumption, 39% of carbon footprint, and 30% of waste output. In order to minimize these negative environmental impacts, many public and private owners are requesting that their buildings be more sustainable and certified under the widely known programs such as leadership in energy and environmental design for existing buildings (LEED-EB). To accomplish this, buildings are increasingly integrating green building measures including energy efficient lighting, motion sensors, thermal pane glass, geothermal heat pumps, EnergyStar rated HVAC systems, photovoltaic systems, and wind turbines. This research paper presents the development of an automated decision support system (DSS) that is designed to optimize the selection of green building measures which can be used to upgrade existing buildings. The developed DSS incorporates two optimization models that are capable of (i) minimizing the total upgrade costs required to accomplish a specified LEED-EB certification level such as silver or gold; and (ii) maximizing the number of accredited LEED-EB points within a specified budget of upgrade costs. The DSS is designed to identify a set of optimal upgrade decisions that accomplishes these two optimization objectives. An application example is used to illustrate the capabilities of the DSS and to validate its result.

Aug 1, 2013

By S. Mao

Total station has been predominantly applied in stationary survey scenarios in construction. With the moving target tracking and point survey automation functions, a robotic total station (RTS) lends itself well to more dynamic applications. Nevertheless, a RTS unit is still unable to track multiple targets simultaneously or to survey a target point when the line-of-sight is temporarily unavailable. In this paper, we propose a methodology to synchronize and automate multiple RTS units intended to address dynamic tracking and surveying applications in the construction field. By using the application programming interface (API) from the manufacturer, we implement the proposed methodology and the prototype system integrates two RTS units in regard to space and time and communicates survey command instructions among RTS units through wireless networks. The two RTS units can be operated to survey the two ends of one swinging sling concurrently in order to retrieve the actual length of the sling within several millimeters accuracy. Besides, in applications where line-of-sight between a target object and one RTS unit cannot be guaranteed all the time, continuous surveying can be materialized by automatically delegating the task to another synchronized RTS unit with clear view of the target object. A field test was conducted to demonstrate the application of the proposed automation approach in which sling length was measured of a rigging framework used for lifting industrial modules. The testing results are presented and achievable accuracy and reliability are discussed. The proposed solution overcomes the limitations of global positioning system (GPS) and laser scanning and holds high potential to provide cost effective solutions to many dynamic field applications.

Aug 1, 2013

By D. Runnels, A. Allaire, J. Torrealba-Vargas

Data mining and modelling of operational data involves the discovery of patterns in large datasets for future use in benchmarking and plant optimization. The modern pattern of discovery in large data sets involves statistical techniques, machine learning and new visualization tools. Former examples of data mining are revisited and presented in this document. INTRODUCTION A network of enthusiastic and active professionals is currently developing and maintaining several open source statistical software tools (packages) for data analysis (example Rstudio, Orange, Spyder, etc.). The advantages of the open source software philosophy are the fast development and testing of the solutions presented to the community. Books and support are available for each software application. Since each modern work activity generates massive amounts of data, it is attractive to learn and test those available tools considering that we are at the door of the new work revolution coined as “Mine 4.0”. Data mining involves collecting large datasets, the preparation and cleaning of a dataset (term named data wrangling), the uploading of the data to a database program capable of handling big datasets, the development of prediction models and the presentation of the results. Machine learning techniques help to develop mathematical models and algorithms that could be used to improve the performance on a specific task. Mine operations are producing an incredible amount of data each day and the need to analyze those results seems to be impossible due to the lack of time, as well as the lack of skills to investigate the data collected. If we add to this the traditional habit of working in silos, an additional challenge is to consolidate databases from different departments in search of trends that could help to optimize production.

Jan 1, 2019

By D. G. Osborne

"The paper describes current 'tools' available to the coal preparation engineer for carrying out the evaluation of data, process design, selection of equipment and layout and design of coal preparation plants.Laboratory and pilot-scale equipment is widely available and test data can be used to provide valuable design information regarding capacities and sizing for specific applications. Pilot plants, unless they fit closely to the basic design envisaged for the eventual commercial plant, C(In often provide only limited useful information.Computing aids such as equipment simulation, plant modelling, etc. are becoming widely applied for establishing design criteria and investigating flowsheet options . Other computer tools such as computer-aided design systems are taking over some of the time-consuming tasks of detailed layout and design and estimation of quantities, etc. and providing the means for detailed examination of more than a single option.Besides computer modelling there is also physical modelling of plant buildings, plant sites and entire proposed mining areas; the former can be especially useful in finalizing design and threading' pipework and electrical reticulation systems through the plant without the resultant risk of impairment of flow, obstruction or wastefulness. Not the least of the benefits of plant models is the assistance provided for training new operating and maintenance staff."

Jan 1, 1985

By D. E. Smith, M. K. Murthy

"The commercial potential of a silica-kaolin deposit that occurs on the banks of and close to the Missinaibi River in the District of Cochrane, Ontario, is under evaluation by Algocen Mines Limited. The geological features of the deposit, as well as its probable origin, are described. Mineralogical analysis of the deposit samples indicates that the principal minerals are quartz and kaolinite clay; it is estimated that about 20 per cent of the deposit is kaolin clay. The impurity minerals present are: a slightly magnetic Fe-Ti oxide mineral, goethite, muscovite mica, tour-maline, staurolite, anatase and zircon. Laboratory research studies are in progress to develop and evaluate suit-able methods for the separation of silica sand from kaolin. Results to date indicate that good-quality silica sand with an Fe,03 content in the range of 0.012 to 0.025 per cent can be produced. It appears that the clay portion can also be beneficiated to yield products meeting commercial requirements. It has been possible to beneficiate a portion of theetlay to obtain the particle size distribution now specified by industry. However, research is continuing to develop suitable separation and beneficiation methods which can produce kaolin clay meeting all the commercial requirements."

Jan 1, 1970

By J. W. Sanger

The establishment of a central steam-heating system in Winnipeg and its inauguration in October, 1924, has attracted a considerable amount of attention. Not only does it excite the curiosity of the engineer, but it has stirred financial and civic bodies throughout Canada to such a degree that there is now a much keener general interest in this particular type of public utility than has been shown heretofore. This does not mean that we may expect a mushroom growth of central-heating systems in all our larger Canadian cities in the near future, but it does mean that the pioneer work which Winnipeg is now doing will undoubtedly be used to guide others in their judgment as to the feasibility of similar projects elsewhere. The success of the municipal hydro-electric system in Winnipeg, and the low rates for electricity resulting therefrom, was without a doubt the most important factor influencing the citizens of Winnipeg to venture into this new field. The events which led up to the central steam-heating proposal in Winnipeg are interesting.

Jan 1, 1926

By S. Orangi

A representative sample of ramming paste from a peripheral seam in an aluminium electrolysis cell was taken in order to develop a process to fabricate ramming paste samples in the laboratory. To this end, paste material was compacted in multilayers in a mould designed to be representative of peripheral seams in Alcoa's smelters. The density distribution in the representative sample was measured ranging from 1.51-1.76 g/cm3. The density range obtained by the proposed methodology in laboratory is 1.47-1.77 g/cm3. The results demonstrate that the proposed fabrication method adequately duplicates paste density from the cell for both one and two layer compaction. Finally, preliminary results related to the compressive strength and Young's modulus of laboratory samples were obtained at various temperatures and are presented in this paper.

Jan 1, 2011

"Conveyed coal flows have been diverted on the basis of real time ash analysis since the 1980s. Many coarse particle separation methods are available through screens, jigs, heavy media separation, particle sorters, to name a few, however bulk diversion requires a representative, continuous analysis to ensure diversion decisions can be made with confidence. Sensors also need to be able to provide measurements at useful time increments so that small tonnages can be diverted for maximum selectivity. Particle separation typically requires high capital costs and there are limitations either in throughput tonnage or particle size or both. Few techniques are able to provide robust and representative analysis of conveyed flows in a useful time basis. Prompt Gamma Neutron Activation Analysis provides multi-elemental analysis of conveyed bulk materials and has been proven in the minerals industry since 2003. This paper outlines the success of this technology in minerals applications in iron ore, phosphate rock and most recently in copper-gold ores, including its use in bulk diversion.INTRODUCTION Naturally occurring quality variability, or heterogeneity, in mineral deposits enables separation and recovery of the valuable components through mining and processing operations. There are distinct advantages in processing the minimum quantity of material to achieve the highest possible yield. Unfortunately, declining ore grades has resulted in larger scale operations and a subsequent loss in selectivity for mining operations. As limits are approached on the practical size of equipment, there is more motivation to investigate alternative solutions. Mining companies are subject to increasing social resistance to growing waste disposal requirements in addition to higher energy and transport costs. Major savings are available by reducing the quantities of material processed where pre-concentration can be effectively applied at early stages in the process. One of the simplest ways to pre-concentrate is to measure the bulk material and reject waste soon after mining so that minimal expense is incurred and that only higher quality material is sent to processing operations. This bulk sorting can occur within the mining operations and has major benefits through energy and other consumables savings. This paper discusses the application of real time analysis technologies suitable for bulk sorting within the minerals industry. Technology that has proven representative for conveyed material bulk analysis and its successful applications to date is explained. Analysis using a sensing technique is only one component of a successful bulk sorting process; the importance of effective diversion systems and a bulk sorting strategy are also discussed. The bulk sorting stage may be one component of a system that could include additional downstream technologies such as particle based sorting systems on a diverted stream."

Jan 1, 2018

By S. Ianos, C. Vibert

Type and shape of large dams founded on rock depend upon the expected deformation of their foundation. Their design consequently requires the assessment of the deformability of the rock mass at large scale. Seismic refraction, laboratory tests on rock samples and empirical formulas can provide an order of magnitude of the deformation modulus, with a limited degree of reliability. Direct in-situ measurement of the deformability of a volume of rock is therefore preferred, which integrate the effect of discontinuities, such as plate loading tests, dilatometric tests, etc. The authors have been compiling results obtained by in-situ deformability tests on a number of dam sites, including the Scarabée (“Petite Sismique”) method. This last method consists in thoroughly analysing the shape of seismic wave forms transmitted through the rock mass. It has been used since now more than 40 years over a large number of dam foundations, and has proved to provide a satisfactory assessment of the static deformation modulus. After comparing the results obtained from different methods on six dam sites, the Authors conclude that their reliability closely depends upon the size of the loading device in relation to the spacing of the discontinuities. Attempts to correlate results from different types of in-situ loading tests reveal difficult, because closely depending upon local geotechnical conditions at test location. Plate jacking tests appear to be the most reliable, because involving a relatively large volume of rock. On the other hand, the Scarabée method (“Petite Sismique”) allows a rapid assessment of the deformation characteristics of the rock mass at large scale, and has been found to provide values generally in agreement with those from plate loading tests, while dilatometric or flat-jack tests were found too dependent upon local conditions. The Authors conclude that preference should be given first to the Scarabée method, which uses light equipment and is quickly performed, together with an accurate geological and geotechnical assessment for interpretation. In a second stage, Scarabée shall be complemented by adequately performed plate jacking tests in selected locations, in order to cross-check results and refine the assessment. The general accordance between the results of the two methods, which both can integrate anisotropy of rock masses, justifies this statement.

Jan 1, 2015

By Donald E. Wakefeld

"The pace at which mining will occur in Northern regions and Arctic lands will depend on the answers to a number of questions. Who are the local aboriginal participants? What land uses are they pursuing? What are their objectives? What is their understanding of the process of mining development? This paper will focus on the last question, communicating the process of mineral development to local aboriginal communities.IntroductionIn the environmental impact hearings for the BHP-DiaMet diamond mine, the smaller Dene Treaty 8 Nation argued for the settlement of its Land Claims as a pre-condition to development. However, the larger Dene Treaty 11 Nation were prepared to permit the mine to proceed on the basis that their people would receive benefits during the construction and operation of the mine.Wherever mining is the significant basis for tax revenues and economic development expectations may be encouraged beyond the realities of the situation. Izok Lake has been known for several decades as a significant mineral deposit but because of its size and the transportation costs involved, it is now a “frozen” ore body. The extent of its mineralization at current metal prices will not support the mining and processing costs without substantial government support for infrastructure and roads. At the opposite side of Canada, Voisey’s Bay clearly satisfies all technical criteria but, nonetheless, two Inuit groups, the Innu, and Métis, have all made LandClaims relating to the mine area.Contrasting the mineral deposits at Voisey’s Bay and Izok Lake emphasizes that the timing of production is dependent on factors such as the grade and amount of reserves, their market price, location and availability of government support. Nonetheless, it is this author’s thesis that given an economic orebody the next most important factor is good communications. It is his view that Arctic mineral development will occur quickly only where good communication has resulted in the trust and mutual respect necessary to implement the mammoth cultural changes required."

Jan 1, 1996

By A. Mitrašinovic, A. Wolf

"The aim of this investigation was to determine the most suitable additive for recovering metals from converter slags generated during Ni extraction. Fluxes analyzed were silica and lime and reductants included pig iron, ferrosilicon and copper-silicon compound. Slag was settled at 1300°C for one hour to simulate the smelting environment. The newly formed matte and slag were characterized by chemical composition and morphology. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with traces of magnetite. Entrained matte was present in the slag mostly as prills of Ni3S2-FeS matrix and a Cu2S-FeS secondary phase below 10µm in diameter. Kinetic parameters of matte formation, valuable metal recovery rates and partition coefficients were deduced. Silica additions generated higher partition coefficients for copper and nickel than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and partition coefficients. Silica additions favoured the formation a higher grade matte while lime additions will hinder metal recovery. Pig iron, ferrosilicon and Cu30Si were the most effective reductants for valuable metals recovery. Cu10Si and coke additions had little to no effect on valuable metals recovery."

Jan 1, 2015

By L. Trytten, S. Bass, P. Nawrocki, J. Mercer

The Sherritt Fort Site nickel refinery and fertilizer plant has been operating continuously since 1954. The ammonia leach process uses ammonia and sulphuric acid, producing nickel and cobalt and an ammonium sulphate byproduct. One of the features of an ammonium sulphate based process is the aggressive nature of ammonium sulphate to concrete and structural steel. After six decades of operation, portions of the structural steel and concrete at the Sherritt facility have become degraded. Infrastructure replacement programs started in earnest more than a decade ago with pipe racks and electrical infrastructure, and have now progressed into building steel. Replacing and repairing this infrastructure within the tight constraints of an operating plant poses several difficult challenges. This paper will outline the approach taken to accomplish this difficult work, and discuss key learnings from the ongoing program.

Jan 1, 2015

By B. Krysa, J. Qiu

The zinc pressure leach plant at HBM&S's operations is now in its fifteenth year of operation. Current pressure leach operation is steady at a concentrate processing rate of around 26.5 tonnes per hour. A new cellhouse with a design capacity of 124,000 tonnes per annum and the capability of expansion of up to 154,000 tonnes per annum was commissioned in July 2001. The potential to expand the capacity of the pressure leach circuit and associated processes, as well as the purification circuit and casting plant, to meet the maximum capacity of the cellhouse has been investigated. This paper reviews current operation of the zinc plant, as well as the possibility of a capacity increase without major process modifications or major capital expenditures.

Jan 1, 2008

By D. K. Matlock, D. J. Hamre, J. G. Speer

Ultrafine ferrite (UFF) grains may be produced in surface layers of plate steels using controlled intermediate cooling followed by deformation. Experiments were conducted using a 0.12 C - 1.26 Mn steel on a Gleeble 1500 hot deformation simulator. Taguchi designed experiments were used to evaluate prior austenite grain size, intermediate cooling rate, intermediate cooling temperature, intermediate hold time and amount of reduction in order to observe the effects of variables and their interactions on the final microstructure while minimizing the number of required test runs. Evaluation of resulting microstructures and mechanical properties revealed a preferred thermal and mechanical history for developing ultrafine microstructures in surface layers of plate steels. Application of the fundamental concepts of phase transformations to industrial plate rolling is considered.

Jan 1, 2004