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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

By J. K. Shaw

The science of low temperature engineering is well entrenched in mining. Uses for common cryogens, including liquid oxygen (LOX), liquid nitrogen (LN2), and liquefied natural gas (LNG) in the gas and minerals industries are reviewed. Potential future applications are discussed within the scope of mining, particularly in refrigeration and ventilation. The second part of this paper focuses on the Linde cycle, which is at the heart of most liquefaction plants. Steady state equations describing the mass and energy flows are presented. The paper concludes by explaining the concept of a wind powered Linde- Hampson cryogenic cycle and assessing, with scoping calculations, the technological feasibility of producing cryogens with an intermittent source of (renewable) energy.

Aug 1, 2013

By D. C. Downing

"I THANK YOU for the invitation which The Mining Society of Nova Scotia extended, originally to Gordon Berry, manager 'of our Point Tupper Refinery, to join you at this meeting and discuss refining and petrochemicals in their relation to this region. There are natural advantages in Nova Scotia which have made possible, and will continue to make possible, sizeable developments both in petroleum refining and in chemicals. Equally, however, as is the case everywhere, there are certain constraints. For clarity in this presentation, I will state some of these constraints right at the beginning. First, of any future developments from now on, only a small proportion of the products can be expected to go into local markets. I can make the point best with a few figures. Petroleum companies all have market forecasts. None ever work out to be perfect, but the trends are relatively predictable and the orders of magnitude are certainly correct. Estimates for the use of all refined petroleum products in the four Atlantic provinces are:"

Jan 1, 1973

By E. Vesely, A. Saxena

"SAG mill liners are designed for protecting the mill shell and providing lifting power for ore charge and grinding media. Due to the impacts from the charge and the grinding media, the liner experiences dimple, plastic deformation, strain hardening, fatigue, peening and final failure. Because of the collisional environment directly measuring such dynamical loads is extremely difficult if not impossible. In this study we tried to evaluate the liner failure risk by simulating the collisions of solid particles with mill liner using Discrete Element Method (DEM). DEM simulation has been proved to be a very useful tool in evaluation of granular flow and its impacts on the solid structure. But there are certain limits in DEM coherently, such as the number of solid elements, the computer runtime, etc. Here we first present the general feature of the particle-liner collision in terms of impact force and collision energy. Then the effects of parameter selection is discussed. Our simulations show the fatal collisional event of huge impact force is very rare and the collisional events of low impact is much more frequent. The fatal event may contribute most to the liner failure. The rarity of the fatal events may be missed in a short runtime simulation. This technical challenge combined with lacking of criterion to evaluate varying impact loads in fatigue problems may further complicate the evaluation. Should we use the largest impact force alone or we should use the more frequent events is an open question and requires more effort. In order to evaluate the quality of liner design, we proposed a relative comparison method. In the end we show the implication and application of this method in liner optimization by a work example. In particular, the effects of the charge level of grinding balls and their size on the operation performance is presented.INTRODUCTION Grinding is one of the most important and expensive steps of mineral processing. A variety of grinding mills such as rod mills, ball mills, semi-autogenous (SAG) mills and autogenous (AG) mills are being utilized for comminution of mineral ores (Gupta & Yan, 2016). Up to today, SAG mills and AG mills have been widely used to reduce operation costs and increase throughput. In an AG mill, a rotating drum throws larger rocks of ore in a cascading motion which causes impact breakage of larger rocks and compressive grinding of finer particles. Unlike AG mills, SAG mills use steel grinding balls to break ores of size quite small such that they cannot be easily broken in AG mill. SAG mill liners are designed for protecting the mill shell and providing lifting power for ore charge and grinding media. Due to the impacts from the charge and the grinding media, the liner experiences dimple, plastic deformation, strain hardening, fatigue, peening and final failure. Quality and performance of SAG mill liners play a fundamental role to enhance efficiency of grinding mills, because failure of liners is the major cause for unexpected breakdown (Banisi, Hadizadeh, Mahmoudabadi, & Eilkhany, 2006)."

Jan 1, 2019

By Haipeng Li, Jacob Masliyah, Barun Gorain, Jian Huang, Qingxia Liu, Zhenghe Xu, AuTec Innovative Extractive Solutions Ltd.

"Froth flotation is widely used to selectively separate one or more minerals from an ore over a wide range of particle sizes with high efficiency. Bubble–particle attachment is one of the most critical steps in flotation. The objective of this project is to demonstrate the need for an innovative dual bubble generator to improve flotation efficiency. This dual bubble generator was designed to generate two different sizes (micron size and typical flotation size) bubbles. The micron size bubbles generated on the crevices of particle surfaces in venturi type of cavitation tubes enhanced the attachment of fine particles to the bubbles in conventional flotation systems. They also acted as a secondary collector, which has the potential to reduce operation cost and improve flotation recovery. The dual bubble generator was evaluated for a double refractory gold ore with 3g/t Au, 1.5 wt% TCM (total carbonaceous matter) and 0.7 wt% sulfides. The results were compared with those obtained using a commercial bubble generator. Compared with the commercial bubble generator, the dual bubble generator showed not only a higher gold recovery, but also an improved separation efficiency, demonstrating the potential of dual bubble generator in fine particle flotation.INTRODUCTIONFroth flotation has been widely used in mineral processing and waste water treatment. However, flotation has been proven inefficient for fine particle recovery although it becomes increasingly inevitable to process fine particles with the depletion of easy processing ores. The critical problem of fine particle flotation is the low attachment of fine particles to flotation size bubbles due to their low collision rate. Based on a commonly acceptable flotation model given by R =F*[Pc*Pa*(1-Pd)], the probability of bubble–particle collision (Pc), attachment (Pa) and particles detachment from air bubbles (Pd) collectively determines fine particle recovery (R) (Yoon and Luttrell, 1986). Since Pc = (3Dp/Db) where Dp and Db are diameters of particles and bubbles, respectively, bubble size and particle size impact the bubble-particle collision in opposite directions. It is evident that the probability of bubble–particle collision decreases with decreasing the size of particles, leading to a low recovery of fine particles. In this case, reducing the bubble size and/or increasing the apparent size of particles by fine particle aggregation are clear means to improve fine particle recovery."

Jan 1, 2016

By W. J. D. Stone

"For several years, the existence of a deposit of barite (BaS04) near Brookfield, Nova Scotia, has been known. A very large deposit of strontium (SrS04) near Sydney, Cape Breton, is a more recent discovery. Cape Chemical Syndicate has been formed to work the deposits. A five-million-dollar integrated mineral processing and chemical plant is planned for Sydney to produce various compounds of barium and strontium. The mineral processing plant includes the Jones Wet Magnetic Separator and will produce high-purity barite and celestite. These products will be processed further in the fine grinding plant and the chemical plant. The general project is described, covering the deposits, processing and markets."

Jan 1, 1969

By D. Gagnon, B. Dubreuil, J. -M. Lalancette, D. Lemieux

"The pilot scale extraction of gold with a brine of sodium chloride and bromide at 30 ºC, in an atmosphere of halogens at atmospheric pressure, leads to gold chloride with 95% gold recovery. The use of dilute hypohalites (1 – 3%) instead of free halogens, which is strong enough to oxidize hypobromite into bromine, simplifies the recycling of halogens by electrolysis. With the recycling of water and brine, the regeneration of hypohalites and with a barren solid that is inert and stable. The Nichromet Extraction technology is a green process where the protection of the environment does not preclude profitability.INTRODUCTIONThe use of chlorides for the extraction of gold predates the discovery of chlorine by Scheele in 1774. In the Plattner chlorination process (Christy, 1888) sodium chloride and copper salt were used to promote gold recovery by amalgamation with variable results. The introduction of the cyanide technology in 1889 has led to a general use of this method for gold recovery. In the last decades, a return to chlorine in extractive processes has been noted (Ferron, Fleming, O’Kane and Dreisinger, 2002), mostly because of environmental pressure for non-cyanide technologies.This paper describes a closed circuit proprietary approach (Lalancette, 2009) developed and piloted by Nichromet Extraction Inc. for the extraction of precious metals with recycled mixed halogens; chlorine and bromine from hypohalites. DESCRIPTION OF THE PROCESSThe attack of gold by halogens can vary significantly. The rate of reaction is substantially higher with bromine (Br2) than with chlorine (Cl2), by a factor of more than five, although the oxidation potential of Cl2 is higher than Br2, as shown in Equation 1a and Equation 1b (Latimer, 1952)."

Jan 1, 2012

By E. Swartzman

"DURING 1951, experimental cleaning studies on both fines and larger sizes of certain Canadian coals were conducted on a relatively large scale in two pilot plants in the United States, large enough to be considered as small commercial units, and in one commercial plant in Canada.One of the pilot plants was a wet washer of a type which apparently has never been .used in Canada, nor has any Canadian coal been tested in it before. In the other pilot plant and in the commercial plant, dry cleaning equipment was used. The commercial plant is the first of its kind to be employed in Canada, and this type is used only to a limited extent in the United States.Fine-Coal Cleaning ExperimentsTest PlantsHydrotator and Hydrotator-Classifier combination pilot-plant with a capacity of about twenty tons per hour. This is a classifier type washer adapted for cleaning fine coal as well as certain intermediate sizes. The Hydrotator deals with that portion of a coal retained on approximately a 24-mesh Tyler sieve, whereas the Hydrotator-Classifier deals with the minus 24-mesh fines."

Jan 1, 1952

By L. E. Puddington, A. L. Mular

"Since the inception of spherical agglomeration, few investigations to exploit commercially the technique in the metallurgical field have been conducted. Of these, none appear to have been carried sufficiently far to demonstrate commercial feasibility.This paper describes a continuous agglomeration-separation process that can rapidly handle large tonnages of ore material. A small pilot plant de-signed from information obtained with the semi-batch unit described herein is currently in operation.In the absence of a reagent recovery system or cheap reagents, the process is probably not economically attractive for many common ores. However, for iron ores, the fuel content of the agglomerates can be used in a subsequent step such as direct reduction."

Jan 1, 1968

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 S. Hopkins, R. Preston, S. Gillis

"This paper examines typical visual inspections of operational soft rock mine shafts and discusses some of the challenges involved, many of which are associated with inconsistent inspection practices. The paper presents the development of a more standardized approach to periodic shaft inspections that supplement the more frequent inspections performed by shaft crews at the mine. This approach helps to keep an accurate record of changing conditions, compare conditions between multiple mine sites, as well as prioritize and plan potential remedial work. INTRODUCTION Shaft inspections, whether they are performed daily or weekly by members of the shaft crew at the mine, or periodically by consultants, traditionally involve a visual inspection undertaken with personnel traveling on an inspection deck on the conveyance, taking notes and photos. Inspections are typically required by mining regulations and carried out to identify and address hazards before a safety incident occurs that could cause harm to people or damage to property, as well as to help plan required maintenance work. Depending on the site, there can be many challenges associated with inspections in the shaft, especially compared to a typical inspection at surface. Some of these challenges are associated with the shaft environment itself, while others are related to the subjectivity of inspections and a lack of standardization, particularly between multiple sites within the same operating company. Recognizing these challenges, a more consistent and repeatable approach to shaft inspections in soft rock mines is evolving. This approach involves reviewing available historical data, comparing sites with similar conditions, establishing survey control, documenting observations and measurements with locations, and updating as-built or condition drawings. Part of this standardized approach is the implementation of an innovative 360-degree camera with a high-power lighting system that can be used either remotely or alongside personnel completing a traditional visual inspection. The system uses six cameras to take photos at a rate of 15 frames per second, with the image data subsequently processed and stitched, then joined into a high-resolution video. This tool improves time-efficiency, objectivity, and repeatability of inspections."

Jan 1, 2019

By W. G. Campbell

"The region discussed comprises approximately eight million acres spreading across the Arctic Circle in Yukon and North West Territories.Encouraged by four years of surface geological and geophysical work, which strongly suggested that suit-able conditions existed for the entrapment of oil and gas, a decision was reached to drill. In due course two holes were drilled; Eagle Plains No. 1 drilled to 9589 in 1957-8 and Western Minerals Chance No. 1 spudded in 1959 is being deepened this year.Thick sections of sedimentary rocks occur on both sides of the Richardson Mountains, however, most of our activities have been concentrated to date on the west side in the Eagle Plains basin. Here are found stratigraphic units ranging from Precambrian to Tertiary age. The drilling of the two exploratory wells proved the presence of these strata at depth and have confirmed the presence of promising structures. A geological cross-section across Eagle Plains presents an interpretation of these conditions.Physical and engineering aspects of exploration in the northern Yukon and North West Territories are de-pendent largely upon seasons and transportation. Reconnaissance gravity and surface geologic mapping by air presents no serious problems. However, seismic operations on the ground are greatly affected by the season, presence of permafrost and mobility of equipment.The actual drilling of the hole may well be the simple part of a wildcat undertaking once equipment and supplies are on location. Over-all planning, assembling supplies, transporting equipment and personnel seems to be the real job. Serious consideration must be given to per-ma-frost effect in the drilling pro-gram and on surface installations as well.Programming for -the various exploration activities should be under-taken well in advance of the actual doing. Considerable extra costs may be the results of crash programs. Costs are high, and the rewards uncertain. Economic evaluation is based •on the long term outlook."

Jan 1, 1960

By E. L. Bruce

Red lake is a body of water some thirty miles in length lying about forty miles northwest of the outlet of Lac Seul. It forms one of several large lake expansions on a river which enters the English river from the north, twenty miles below Lac Seul. Before the construction of the National Transcontinental railway a long canoe journey was necessary to reach that part of the English river, and Red lake, two days travel beyond, was one of the furthest outposts of the trading companies in that difficultly accessible triangle of country between Lake Winnipeg, James Bay and the English and Albany rivers. The Hudson's Bay Company post at Red lake is said to be one of the earliest established in the district but there are no records at the post, and as the English and Albany rivers never were used to any great extent as travel routes there is no mention of the place in the diaries of any of the early explorers. Dr. Bell passed through Red lake on his excursion to the Berens river country in 1883, and a brief note mentions that Huronian rocks were seen. To Dr. Dowling, however, belongs the credit for the first thorough description of this basin of sediments and basic volcanics. In 1893 he followed the course of Dr. Bell's trip, of ten years previous, through Red lake to the upper part of the Berens river.

Jan 1, 1926

By E. A. Morris

It has been shown that Alberta oil-sands fluid coke can be effectively used to reduce SO2 to elemental sulphur while simultaneously producing sulphur-impregnated activated carbon (SlAC). In the capture of mercury from industrial flue gases, SIAC has proven to be a highly effective adsorbent material. The current research aims at developing an existing SlAC technology to meet the needs of copper smelters for mitigating both mercury and SO2 emissions, while making elemental sulphur as a co-product. The challenge behind this undertaking is that these flue gases generally contain percent levels of 02 and H20 vapour (2-12%). The focus of this study is therefore on the feasibility of reducing SO2 using fluid coke under copper smelter flue gas conditions, as well as the optimisation of SIAC properties for capturing vapour phase mercury. It is hypothesised that mercury capacity is strongly affected by the 02 potential of the activation gas due to changes in surface sulphur types arising from different reduced sulphur species. To verify this, gas chromatography is used to analyse the reaction products while XPS and XANES will be used to describe the nature of sulphur on the SlAC surface. CVAFS analysis of mercury capacity will finalise the hypothesis assessment. Preliminary results indicate that 02 at 5% does not play a significant role in SSA or pore development. As expected, increased residence time contributes to SO2 reduction and elemental S yield.

Jan 1, 2007

By T. G. Joseph, M. Welz

ABSTRACT: Joseph (2002) introduced passive seismic monitoring to measure mining equipment performance. This paper evaluates the potential of passive seismic monitoring to correlate mining equipment operation with oil sands surface response, with a mining hauler as the seismic source. When applied to moving haulers, this action–reaction approach is complex. Vibrations from on-board equipment, such as pumps and tires, dirty the signal with noise. To facilitate any correlation, the signal must be cleaned up. Existing geophysical analytical techniques were manipulated to evaluate the noise problem and to filter sufficiently to permit an evaluation of whether a mining equipment action–ground response relationshipis in fact discernable.

Jan 1, 2011

By A. A. Brant

"Improving geological and geophysical evaluation should serve to reduce the early-stage risk assessment and there-by contribute to exploration expenditure stimulation. The limitations of present-day methods are reviewed, particularly as to anomaly causes, depth penetration and quantitative physical interpretative abilities. Some of the problems now under study are discussed. Future developments expected include the treatment of quantitized geologic and geophysical data, as well as continuing attempts toward computerized interpretation."

Jan 1, 1967

By W A. Bardswich

The numerous factors associated with the prov1s1on of satisfactory air conditions in hot and humid Canadian mines are described. The main heat sources are auto-compression and the actual flow of heat from the rock. Temperatures reach 97°F at a depth of 8,100 feet. Various methods used in coping with high temperatures are described, including the use of ice stopes and heat exchangers. Moisture control, desirable air volumes and velocities, sizes of airways and methods of distribution are important considerations. A comparison of the temperatures, humidities and types of airways of two deep mines should prove useful in the design of future ventilation systems. Introduction OUTDOOR temperatures in northern Ontario vary from a low of around -40°F in winter to a high of about +90°F in summer. The average annual mean temperature over a 12-year period was +35°F, with a summer mean of 54 o and a winter mean of 16°. Because of low outdoor temperatures, a number of northern mines must heat fresh air for underground ventilation in winter; others, with high rock temperatures, are faced with a year-round cooling problem.

Jan 1, 1965

By M. S. Fotheringham

Recognition of the Growing Importance of Iron and Steel Few Canadians have yet become aware that Canada's vast iron ore resources, the greater part of which is only now beginning to be developed, will inevitably have a profound effect on the entire Canadian economy, benefitting in some measure the lives of all Canadians. The great iron mining developments of Ontario, Newfoundland, Quebec, and Labrador are destined to make Canada one of the world's major producers and exporters of this material, on which our industrial civilization is?based. These developments will create new employment, new communities, new transportation facilities, and new investment opportunities. Iron ore is the foundation and the keystone of modern mechanized civilization. The most prosperous nations of the world are the highest per capita consumers of iron and steel, and in these countries the per capita consumption is increasing steadily despite the advent of light metals, plastics, and other competitive materials. Three-quarters of the human race have too little steel -and consequently too little mechanization -to provide for themselves the necessities and comforts of civilized living. Progressively they will demand, and acquire, the machines, the transportation and communication facilities now lacking, and they will win them by making greater use of the world's iron resources. It is the good fortune of this generation that Canada's 'iron age' is just getting well under way.

Jan 1, 1951

By T. C. Holmes

"Dome mine, in the Porcupine mining camp of northern Ontario, is one of the important gold mines of Canada, its production of gold from the commencement in 1910 to the end of 1946 having a value of $149,000,000.GENERAL GEOLOGYThe oldest rocks in the mine are greenstones of Keewatin age(l). Those to the south are known as the southern greenstones, but little is known of their structure. Those in the northwest part of Fig. 1 and the north part of Fig. 2 are known as the northern greenstones or greenstone 'nose'. They face north, dip steeply north, and end to the east against an unconformity which pitches northeast about 20°. The volcanics are overlain unconformably by Timiskaming .conglomerate and slate. All these rocks are cut by porphyry. Closely associated with the porphyry is a group of rocks that have suffered extreme alteration. Diabase dykes intrude all the other rocks and the ore. The principal massive rocks in the mine are two adjacent flows known asthe andesite (south) and dacite (Fig. 1). They are composed chiefly ofmassive, medium-grained lava. Pillows, flow lines, and other typically volcanicfeatures are found along the tops of both flows and at other places in theandesite. These parts nearly everywhere show a slight schistosity panllelwith the flows except in the orebodies, where they are massive."

Jan 1, 1954

By Suman Giri

Non-Intrusive Load Monitoring (NILM) is a method of extracting appliance-level power consumption information from aggregate circuit-level data with the goal of giving users feedback regarding their energy consumption so they can take control of their consumption habits. In this paper, we present a novel algorithm for classification of on and off states of appliances. We compare the performance of our algorithm in on state detection with a pervious paper that evaluated the same dataset and show that it performs up to 13% better. We also present the results of a case study where we collected data for different modes of a cooktop, microwave and dishwasher and used our algorithms to perform power estimation. The error on ten different setups in the test bed ranges from 1% to 32%. We discuss our results and lay out ideas for future work.

Aug 1, 2013