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By T. G. Carter

"Tremendous progress has been made in recent years towards developing computational tools that allow ready solution of most common rock engineering problems, with amongst the most advanced of the tools focusing on evaluating engineered openings within Synthetic Rock Masses. These new codes have the potential to allow much more realistic design, but they must not be used without careful calibration – prior to – during and – post completion of any modelling. This paper explores some of the pitfalls of inadequate data collection and suggests more emphasis be given to calibration. Guidelines for minimum levels of parameter data are suggested for improving application of basic to sophisticated modelling codes.INTRODUCTION & BACKGROUNDTremendous progress has been made in recent years towards developing computational tools that allow ready solution of most common rock engineering problems. The degree of sophistication now possible with some of the available codes allows one to tackle extremely complex problems that were not thought tractable even a decade ago. Indeed, generation of synthetic numerical rock masses, based on discrete fracture network representations that closely mimic actual rock mass conditions, such as are shown in Figure 1, is today relatively straightforward, and not as user-challenging as employing state-of-the-art codes of even a few decades ago. This is largely because major improvements in computer graphics and in availability of ready-made user-friendly input-output interfaces have paralleled development of these new codes, now in some cases outpacing actual new analytical/procedure developments. This is something of a reversal from the first few decades of DOS-based rock engineering computational experience, when only rudimentary graphics were available and user-friendly input-output interfaces were virtually non-existent."

Jan 1, 2015

By W. E. Oching, M. M. Ghomshei

Attracting and retaining workers in mining industry has become an uphill battle to many mining companies. As workers with significant experience retire, it is getting more difficult to attract not only new workers but also top talent to the mining industry to replace professionals exiting the workforce. To make matters worse, students’ enrolment in the post-secondary mining programs in Canada and USA is continuously declining year after year for reasons not directly linked to job market. This raises a question of how can the future needs of mining be met? This paper focuses on avenues for collaboration of industry and educational institutions to meet the current and future needs of mining. It provides effective approaches that mining institutes can engage with program advisory committees, role of the mining industry in supporting both faculty and students, how to harness the benefits of diverse workforce in the country and use of innovative technologies to attract young workers in mining. This work presents Human Resources (HR) professionals with tools that they can use to hire and retain skilled workers with strong interest to work in the mining industry. It also provides HR professionals with an opportunity to re-evaluate their restructuring practices during economic downturns as they reduce number of employees on temporary or permanent basis. The paper stresses the need of working together of the mining stakeholders including mining industry, academic institutions, First Nations’ communities and provincial(state) and federal governments to meet the current and future demands of mining as the industry experiences shortage of labour and low students’ enrolment in post-secondary mining programs. It is shown that mining educational institutes can enhance their programs and recruitments through establishing a better communication with all stakeholders. This communication can be facilitated by creating a national advisory board, to work with all mining programs at the national level for sustainable mining.

Jan 1, 2023

By T. Grammatikopoulos, SGS Canada Inc.

"The Nechalacho rare metal deposit, located in the Northwest Territories, Canada, is currently being taken through Feasibility Study by Avalon Rare Metals Inc. QEMSCAN analysis and supplementary electron microprobe analysis were utilized to identify and quantify the mineralogy of the deposit, and determine REE distribution among the minerals. QEMSCAN mineralogy was performed to provide textural information on the mineralization, determine the variability of the ore and identify REE domains, and the liberation and association of the REE minerals. The sample matrix consists predominantly of silicate minerals. The REE minerals include allanite, monazite, synchysite, columbite, fergusonite, and bastnaesite. Zircon is present in considerable amounts and is a REE carrier. Fergusonite and zircon account for most of the HREE, and monazite, allanite, synchysite and bastnaesite the LREE. QEMSCAN mineralogical data is extremely valuable in assessing the mineralogy of the ore. The data are implemented to define the mineralogy of the ore body, support metallurgical test work, and predict recoveries and grades.INTRODUCTIONThe term rare earth elements (REE) is used to describe the 15 lanthanide elements or metals and, more recently, the metals yttrium and scandium, which display similar physical and chemical properties.Economic and potentially economic REE deposits form two main groups, a more commonly occurring “light rare earth element” (LREE) group containing lanthanum, cerium, praseodymium, neodymium, and samarium and a less commonly occurring “heavy rare earth element” (HREE) group which, in addition to the LREE, contains elevated concentrations of the more valuable REE, europium, gadolinium, terbium, dysprosium, holmium, yttrium, erbium, thulium, ytterbium, lutetium and scandium. The first group is hosted primarily by carbonatites and the second by highly alkaline (Na + K > Al) silicate igneous rocks. The LREE are produced mainly from bastnaesite, monazite, etc., while HREE are produced almost exclusively from low-grade secondary ion adsorption clay deposits in which the REE are adsorbed onto the surfaces of kaolinite and halloysite, clay minerals produced by the weathering of granite and sediments. HREE are also found in fegusonite, zircon, xenotime, etc but are not produced presently from these minerals. China is responsible for 97% of the World’s production of the REE, mainly from the giant Bayan Obo, carbonatite-related deposit and from the clay deposits mentioned above.Quantitative automated mineralogy is increasingly being applied to ore deposits. It helps users to understand and improve mineralogical parameters for geological and metallurgical purposes. Data include textural characterization, to quantification and distribution of ore and gangue minerals, liberation and association of the REE minerals. The data can be used to define mineralogical domains and predict the metallurgical response of the ore (Gunning, de Souza, & Grammatikopoulos, 2009)."

Jan 1, 2012

By D. M. Morrison

"Microseismic systems at five mines in the Sudbury Basin provide the basic data for Falconbridge Limited's rockburst research. Daily and long-term analysis of this data as well as underground observations has confirmed the fault-slip mechanism of rock bursting at three mines. A detailed analysis of the complete history of Falconbridge Mine is being conducted and Distinct Element numerical models are being used to simulate both the stick-slip behaviour of faults and the dynamic effects of the induced vibrations on rock and backfill. University research includes acoustic tomographic imaging of the rock mass based on seismic wave propagation and collection of full micro seismic waveforms to allow application of advanced seismic and statistical analysis techniques. INTRODUCTIONFalconbridge Limited currently has five mines operating in the Sudbury Basin: East, Lockerby, Onaping, Fraser, and Strathcona Mines, which along with the Falconbridge open pit produced 2.8 million tonnes of ore in 1986. The underground mines range from about 600 m to 2000 m below surface and one of the consequences of mining at these depths is the occurrence of rockbursts.Research into rockburst phenomena at Falconbridge began over 25 years ago and research is continuing in an effort to avoid the problem by improved mine design, to protect mine openings from damage by design of effective support systems and to better understand the processes which precede a major fault slip rockburst. Since the early 1980s, significant progress has been made due principally to micro seismic monitoring and advances in microcomputer technology coupled with detailed underground investigations.It is now possible to identify the fault-slip mechanism as the cause of many of the rockbursts which occur at Falconbridge mines. By gaining an understanding of effect of mining-induced stresses on the pre-existing geological structures, areas which may experience rock bursting can be identified and can be protected against severe damage by appropriate support techniques."

Jan 1, 1989

By Robert B. Parsons

"Two recent decisions by the Canadian courts could reduce the taxes paid by many profitable mines in Canada. At a time when the mining sector is hurting from an ever increasing tax burden and soft prices, the results of two cases are welcome news. Mining companies are well advised to check prior years' tax returns in the context of these developments. IntroductionSince 1976, the income tax legislation has provided a reduced rate of tax for taxpayers engaged in the mining of mineral resources, through the mechanism of the ""resource allowance"". The deduction given for the resource allowance effectively reduces the federal rate of tax by one quarter on resource profits. In general terms, ""resource profits"" are defined to include a taxpayer's income from: the production and processing in Canada of ore to any stage that is not beyond the prime metal stage (or the pellet stage or its equivalent in the case of iron ore); and, royalties computed with reference to the amount of value of production from mining operations in Canada.In computing income from these sources, the taxpayer must deduct expenses that may reasonably be regarded as applicable to those sources, with the exception of expenditures for Canadian exploration and development or financing costs.As a result of the mechanics of the calculation of the resource allowance, one quickly realizes that the lower the expenses deducted from the resource profits, the higher the resource profits and consequently the higher the 25% resource allowance. The impact of the recent court cases is to narrow the range of expenses which are required to be deducted in the determination of the resource profits.The two cases are outlined below."

Jan 1, 1991

By H. R. Butler, R. N. Browne

"The International Nickel Company of Canada Limited consumes some 33 ½ millions of gallons of fresh water and reuses more than 100 millions of gallons of water daily. The continuing search for suitable recycle methodology has enabled the Company to put one 25,000 TPD mill on line utilizing recycled water entirely and a second 35,000 TPD mill is under construction which will likewise employ the concept of recycled water. Future milling plans are aimed at the replacement of all fresh water with recycled water, including sewage effluent and mine waste water.WATER REUSE AT INCO’s SUDBURY MILLSAs man searches unexplored horizons for new and economic industry, he must be constantly and acutely aware of the presence or absence of that precious commodity without which Industry, indeed Man himself, could not survive -- W A T E R. The water requirements of the world today are magnanimous, considering that in 1960 the estimated consumption in the United States was over 300 billion GPD (l) or more than 1,700 GPD per person(5) The magnitude of the problem can be visualized as one considers that three times this quantity of water will be required in the United States by the year 2000, when the dependable supplies of water are estimated to be only two-thirds of that required(2). How, then can we continue to wreak such havoc on that life-sustaining substance - WATER?"

Jan 1, 1970

The introduction consists of back-ground information, of an historical and statistical nature, relating to the Thompson mine. The geological presentation is based on illustrations that are intended to provide a progressively closer look at the ore occurrence. The illustrations consist of an index map, a geological map of a 15-by 85-mile area including the Thompson mine, a series of four maps dealing with the geophysics and geology of a 6-by 4\f.j-mile area at Thompson, a mine level plan and corresponding section, two sto11e 11lans and corresponding sections, and photo-graphs and photomicrogra11hs of the various one types. T HE Thompson mine is located about 400 miles due north of Winnipeg. The ore deposit was dis-covered in February, 1956. Five years later on March 25, 1961, the Thompson production facilities were officially dedicated with the shearing of the first nickel produced at the Thompson refinery. Full production, at an annual rate of more than 75,000,000 lbs. of refined nickel, was attained later in the year.

Jan 1, 1963

By S. Espley, T. Nyabeze, D. Beneteau

"Many mentorship programs are available to Canadian mining industry employees. Some are company-led initiatives, whereas others are provided through educational institutions or nonprofit organizations. In 2016, a national survey was launched to gain insight into perceptions of what mentorship is, learn about available programs, and collate experiences with formal and informal mentorship opportunities. This paper outlines survey findings and delivers recommendations to industry for consideration in employee mentorship programs. In addition, mining industry leaders share their mentor/mentee perspectives. The intent of this paper is to bring awareness of best practices that can help employees grow and develop in their profession.RÉSUMÉ Les employés de l’industrie minière canadienne ont accès à de nombreux programmes d’encadrement. Certains sont des initiatives menées par les sociétés, d’autres sont proposées par le biais d’établissements d’enseignement ou d’organismes à but non lucratif. En 2016, une enquête à l’échelle nationale a été lancée en vue d’obtenir des informations quant à la perception de ce qu’est réellement l’encadrement, de découvrir les programmes proposés et de comparer les expériences aux possibilités d’encadrement, officielles ou non. Cet article présente les résultats de cette enquête et fournit des recommandations à l’intention de l’industrie afin qu’elle les prenne en compte dans ses programmes d’encadrement des employés. En outre, des chefs de file de l’industrie minière partagent leurs points de vue conseillers/protégés. L’intention de cet article est de sensibiliser les employés aux meilleures pratiques, ce qui les aidera à évoluer et à se développer dans leur profession. INTRODUCTIONThis paper about mentorship in the mining industry is based on voluntary responses to a cold survey, written and circulated by the authors. In 2016, a link to an online mentorship survey was circulated to males and females in the mining industry with the belief that mentorship programs should be available to everyone. The link was delivered via the authors’ personal networks in mining, the CIM Reporter, Women in Mining (WIM) email blasts, LinkedIn, and Facebook. This paper summarizes the answers to the survey questions. The paper is a follow up to one by the same authors (Nyabeze, Espley, & Beneteau, 2010), which was written to gain insight into why women join and stay in the mining industry, and to learn why the overall representation of women is low."

Jan 1, 2018

By F. W. Gray

A GEOLOGICAL study seeking to determine, for economic purposes, the value of the Sydney coalfield as a source of coal supply. Limitations of the coalfield come under two main heads: (a) Areal extent of the undersea coalfield. (b) The distance from shore at which coal can be mined at a cost of production permitting its profitable sale. Conclusions reached are that the areal extent of seams below the Phalen seam is of. small economic importance, and that non-persistence of these seams in full thickness and quality in the undersea extension of the coalfield will put an end to profitable mining before any limitations connected with distance from the shore-line become operative. With respect to the Phalen seam, non-persistence or deterioration of the seam will become effective in the western part of the coalfield, and less certainly in the eastern part of the coalfield, before operation of limitations by distance from shore. In the central portion of the coalfield, the seam probably persists in commercially workable thickness and quality to beyond the limit of mining set by distance from the shore-line. With respect to the seams above the Phalen seam between the Mountain fault on the extreme western boundary of the coalfield and the assumed termination of the deposition area on the eastern extremity of the field near South Head of Morien, there appear to be only such limitations as arise from engineering approach, distance from shore, sufficiency of strata cover between the sea-floor and the upper coal seams, and quality of the coal (with certain reservations as to the continuity of the upper seams under Sydney harbour and in the Sydney Mines-Little Bras d'Or district). Some of these seams have fragmentary land outcroppings from which their persistence seaward is assumed, and there may be other and still higher seams in the strata column which are entirely submarine.

Jan 1, 1941

By A. Desbiens, A. Pomerleau

During the summer of 1994, a new PID-based control strategy was installed on line B of the grinding circuit at the Kidd Creek Division of Falconbridge Ltd. Part I of this paper described the methodology used to select the appropriate control strategy using a phenomenological dynamic simulator. Part II presents the implementation of the control strategy. Prior to the controller installation, it was necessary to solve various problems related to the process, such as a cyclic behaviour of the rod mill feed tonnage, a problem related to the mill water source and the calibration of the flowmeters. Once these problems were solved, the control strategy was accomplished in two steps. Step 1 corresponds to the installation of control loops to regulate the pump box level and the cyclone overflow density. Step 2 describes the implementation of a loop to control the cyclone feed density. According to Part I, a loop to control the circulating load is also part of the original design. However, reasons are given to explain the rejection of this loop. For both steps, technical procedures such as filtering, process identification and controller tuning are detailed. Finally, the operator’s interface is briefly described.

Jan 1, 1997

By D. Holz

In this work we present a novel level set-based model for the real-time simulation of soil deformations. A level set defined by a signed distance function and sampled in a regular 3D grid represents and tracks the soil volume under deformation. Moving away from classical 2.5D heightfield representations of soil to a full 3D volume representation allows for improved tracking of cutting tool operations and the simulation of near-vertical or vertical soil faces. The proposed level set representation furthermore provides a versatile mathematical platform for modeling additional effects such as soil slip, and does not suffer from the sampling limitations of commonly used heightfields. Cutting forces applied to the tool are simulated via a formulation based on the Fundamental Equation of Earthmoving, modified to support inclined soil surfaces and transient states of tool motion. Discretisation of this 2D cutting force model with respect to the tool surface allows capturing the effects of irregular 3D terrain shapes on blades and buckets. The surcharge created during cutting operations is tracked in the form of particles and included in the soil failure force computation. We make use of an adaptive, hybrid level set-based and particle-based soil deformation scheme, which allows the soil deformation to be simulated in real-time.

Aug 1, 2013

By K. J. K. Weglo, M. U. Savich

"At the Falconbridge Limited, Canadian Nickel Division, Sudbury Operations, we investigated the ""NO NOISE"" ear muffs model NN3-F which is a Swedish product with foam-filled sealing rings (the Hellberg Standard Volume Hearing Protector). It is used extensively at Falconbridge mines in Sudbury.The research which was carried out in the four Falconbridge mines was conducted under three different headings: manufacturer's attenuation data (psychophysical method), clamping force and head size (bizygomatic diameter), and attenuation tests (physical methods) under working conditions.Manufacturers of hearing protectors claim their products offer noise reductions of 23 decibels (NRR) or more, but they fail to point out that this reduction is obtainable only under ideal conditions. The reality of attenuation under working conditions, as several studies have found, is quite different.Methods for using short measurements to determine the noise exposure index, and for controlling muff-wearing habits, were developed at the Elliot Lake Laboratory. Measurements taken at Falconbridge on ""NO NOISE"" ear muffs revealed that they have a practical attenuation of some IO to 13 decibels. It is important to note here that measurements also revealed that clamping force (thus attenuation) was in an inverse relationship with ear muff comfort. Measuring attenuation using noise dosimeters was a difficult job. Not a single surveyor would accept these measurements (physical method) for absolute accuracy. Apart from that, it was impossible to measure, in one shift, more than two work stations. Because of this, we sought a solution: measuring head size and clamping force in relation to actual attenuations.A detailed analysis of the relationship between attenuation and head size/clamping force was done at four mines. Standard deviation ellipses (standard error ellipses) for head size versus clamping force are in close agreement with measurements that were carried out. In order to measure clamping force an apparatus was constructed and a method for measuring suspension system durability is described in Appendices Band C of this report. At the same time we sought to reduce deterioration of ear muffs in mines as well as to put in place a system whereby attenuation can be controlled and improved. The clamping force apparatus can be operated automatically. The proposed control system is quick, simple and efficient . This system is equally applicable in small and large mining operations, and it can be totally automated and the data computerized for audit of the results. This control system is a new step in controlling ear muff attenuation in working environments.From these measurements of NN3-F ""NO NOISE"" muffs it can be concluded that ear muffs are not the total solution to protect the worker from noise.As the results were evaluated folio wing measurement, Falconbridge switched from the NN3-F ""NO NOISE"" muffs to approximately 90% Mark V ""NO NOISE"" muffs and 10% Mark V MSA muffs. These new muffs showed much better head size versus clamping force relationship and can be expected to produce 14 dBA or better attenuation of noise. RESUMEUne étude des casques antibruit ""NO NOISE"" modèle NN3-F, de fabrication suédoise, avec anneaux d'étanchéité en mousse (dispositif de protection contre le bruit ""Hellberg "" pour volume ordinaire)a été effectuée Ii la Falconbridge Ltd. , Division canadienne du nickel aux installations de Sudbury . Ces casques sont largement utilisés dans les mines de la Falconbridge Ii Sudbury.Cette étude aeu lieuen milieu de travail dans les quatre mines de la Falconbridge sous trois rubriques différentes soit: les données d'atténuation du bruit du fabricant (méthode psychophysique), la force de serrage et la taille de la tète (diamètre bizygomatique), et les essais d’atténuation de bruit (méthodes physiques). Les fabricants de dispositifs de protection contre le bruit prétendent que leurs produits offrent une réduction du bruit s'élevant Ii"

Jan 1, 1986

By J. Tuzo Wilson

"AT ANY TIME, it is a pleasure to me to be invited to address The Canadian Institute of Mining and Metallurgy because it represents an industry and men with whom I have been happily, if peripherally, associated continuously for forty years. This year, it is a particular pleasure because I believe that an important subject has arisen which I propose to discuss.This is a major discovery in the earth sciences, first fully revealed this winter, but already widely accepted. The basis of this revolution, for it is no less, is that measurements of three different features of the earth all change in exactly the same ratios. These ratios are the same in all parts of the world. The results from one set are thus being used to make precise numerical predictions about all the sets in all parts of the world. No such accurate correlations and predictions have ever been found before in geology or areal geophysics. The whole subject of earth science has thereby been radically altered.The first of these measurements is that of the direction of magnetic polarity in lava flows. When piles of young lavas are examined with the aid of a pocket compass, it is noted that some flows are magnetized in the direction of the earth's field and some in the reverse direction (Figure 1). By accurately dating enough flows, a time scale of the dates of reversals has been established. During the past four million years, nine reversals have occurred synchronously all over the world (Cox, Darymple and Doell, 1967, McDougall and Chamalaun, 1966) (Figure 2). It appears that the scale can be extended back to Precambrian times (McMahon and Strangway, 1967). This time scale is the first of the 'three identical ratios."

Jan 1, 1968

By B. Voyzelle

The deterioration of highway and bridge infrastructure has received considerable attention in recent years because of the billions of dollars needed for repair and rehabilitation. A major factor contributing to this problem is the corrosion of steel reinforcement. Reinforcing steels with good corrosion resistance and relatively low price are therefore essential for maintenance, cost reduction and service-life extension of the steel-reinforced structures. This article describes the development of low-alloying steels that offers good corrosion resistance with reasonably low cost. Topics include steel microstructures, mechanical properties, corrosion performance, industrial applications and economic aspects.

Jan 1, 2005

By H. D. Goodfellow, R. A. Elliott

"This paper covers the evolution of large mills and autogenous grinding and compares grinding practice in the iron ore industry with that in the base metal industries. Comments on novel methods of grinding are presented for discussion. Recent developments in the field of classification are briefly reviewed. A systems analysis approach to grinding circuits is discussed. Finally, a point is made for establishing a group within the industry with the purpose of developing a comprehensive evaluation of grinding research and development."

Jan 1, 1971

By I. V. Kojo

Continuous development of technologies has been self-explanatory for Outokumpu Technology's engineers for decades. The aim in the development has always been the improvement of profitability of the copper production but also the sustainability of the processing i.e. high copper recovery, low external fossil based energy utilization, high emission captures and of course low operation and investment costs. Outokumpu Technology's long-term view of the development is a change towards continuous processes and elimination of number of unit operations in smelting i.e. elimination of possible sources of emissions. Outokumpu blister smelting processes i.e. Outokumpu Direct-to-Blister Flash Smelting and Kennecott-Outokumpu Flash Converting have shown excellent operational results during the years of operation and it is expected that soon more than 10 % of the world primary copper is produced by these technologies. The paper will give some background of this development trend.

Jan 1, 2007

By Evelynn Stirling

"The paper/presentation will review the evolution of diesel technology from older diesel engines (1990 vintage) through to the latest technology as a result of the ever changing emissions regulations. It will encompass the EPA Tier levels as well as the latest Euro Stage V emissions. The next step with technology will be to address the CO2 emissions, which translates to improving fuel efficiencies of the product as well as other technologies like battery electric, hybrid and fuel cells. As technology progresses it also becomes important to improve connective diagnostic systems to support maintenance practices and improve efficiencies. What will also be presented will be the key emissions changes to the different gaseous and particle mass elements as the products have transitioned from the EPA Tier 3 through to Tier 4 Final regulations. Offering a range of different technologies to the underground mining market matters as not all pieces of equipment will perform optimally due to its duty cycle and application. INTRODUCTION Rudolf Diesel built his first well-known prototype of the high-compression engine in 1897. Since that time, the diesel engine has evolved into one of the world’s most capable and reliable forms of power generation. Diesel engines can be found in a wide variety of vehicles and equipment, powering everything from agriculture and construction equipment to power generators and marine vessels. In the early days the emissions from diesels was very poor and extensive work has been accomplished over the decades to make the product more environmentally friendly. This is more important in underground mining where the space is limited and ventilation is expensive and challenging. DISCUSSION The key driver of the development of diesel technology is the legislation globally around engine emissions. The emission level requirements over the years has forced diesel engine manufacturers to build a deep technical understanding of the system and how to innovate and optimize key elements of the engine. Cummins expertise has been built over the years as the diesel engine has evolved from a relatively simple mechanical engine to an electronic system with advanced air handling, fuel system, after treatment, and controls. Cummins has also continued to expand into systems beyond diesel, including natural gas. Many new components have been added to diesel engines to reduce emissions while improving fuel efficiency and reliability and, at the same time, reduce the total cost of ownership to the customer."

Jan 1, 2019

By A. Oja, M. Lahtinen, P. Salonen, B. Saxen

Most of the secondary and low grade zinc raw materials cannot be treated successfully by either conventional roasting - leaching - electrowinning (RLE) process or even by atmospheric direct leaching process. The problems arising especially from high impurity content of these raw materials can be effectively solved by implementation of the solvent extraction process. The utilization of solvent extraction process has been demonstrated by Outotec with raw materials like Waelz oxide, crude zinc oxide and zinc containing concentrator tailings. Based on batch and continuous test work it has been shown that SHG quality zinc can be produced even from the lowest grade raw materials. Impurity control in the solvent extraction process has been examined. The solvent extraction process is the key feature of the whole zinc plant for such raw materials. However, design of the entire zinc process including neutralization and bleed treatment is important for optimization of investment and operation costs of the plant. Very careful evaluation of the zinc process with modern simulation tools is essential. The optimized Outotec zinc process ensures a sustainable and profitable process containing minimal effluent and requiring little residue treatment.

Jan 1, 2014

By Min-Yuan Cheng

Heavy rainfall and typhoon oftentimes cause the collapse of hillslopes across mountain roads. Disastrous consequences of slope collapses necessitate the approach for predicting their occurrences. In practice, slope collapse prediction can be formulated as a deterministic classification problem with two class labels, namely ?collapse? and ?non-collapse?. Nevertheless, due to the criticality and the uncertainty of the problem, evaluating the collapse susceptibility of an area is a challenging task. This study proposes a novel Artificial Intelligence (AI) approach, named as K-Nearest Neighbor Based Bayesian Classifier (KNNBC), to deal with slope collapse assessment. In the proposed model, Bayesian inference is used as a framework to achieve probabilistic prediction of slope collapse. Meanwhile, K-Nearest Neighbor (K-NN) is employed as a density estimation technique. Equipped with probabilistic outputs, the K-NNBC is able to yield predictions with different levels of confidence and diminish misclassified cases. Experimental results point out that the proposed model is very helpful for decision-makers in slope collapse assessment and disaster prevention planning.

Aug 1, 2013

By J. Laganiere

A considerable part of the sulphuric acid requirements of the Aluminum Company of Canada's Arvida smelter comes from the burning of 180-200 tons per day of zinc '"'sulphide concentrates in a 22-ft.-diam-eter fluidized bed roaster. The plant and its operation were fully de-scribed in a publication that appeared about ten year ago (1). A simplified flowsheet of the roasting and gas-cleaning sections of the plant is given in Figure 1. The wet zinc sulphide concentrates are un-loaded into a pug mixer, by means of a Pay loader, and mixed with water in a mixing tank to make a slurry of 80 per cent solids. The slurry is transferred to a .feed tank and then introduced into the roaster at a point four feet above the constriction plate, which is the height of the settled bed of zinc calcines. The roasting temperature is con-

Jan 1, 1963