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By N. Parnian

"Carryover of caustic soda (NaOH) in the steam path caused catastrophic failure of superheater 304H stainless steel tubes in a steam generator and led to an unexpected shutdown after just five months of continuous service of petrochemical following the start of production. The cause of the failure was studied, with a focus on the formation of sigma phase in the weld joint and effect of caustic embrittlement on stress corrosion cracking (SCC). The cracks were examined at the seam weld, heat affected zone (HAZ), and Ubend areas. Hardness was measured for the base metal, HAZ, and weld metal, and microstructures were examined using optical microscopy and scanning electron microscopy (SEM). Crack initiation is attributed to gouging on the precipitated carbide at the HAZ and also the formation of sigma phase in the weld metal, as shown by energy dispersive X-ray (EDX) analysis. In addition, cracking was propagated by caustic embrittlement because of residual stresses and hammering. Finally, the characteristic feature of fracture was illustrated by SEM fractography, and consists mostly of intergranular SCC and some quasicleavage transgranular. INTRODUCTIONThree key factors are needed for the initiation and propagation of intergranular stress corrosion cracking (IGSCC): a susceptible material, a corrosive environment, and sufficient stress. Although austenitic stainless steels are susceptible to sensitization and IGSCC, they are widely used in boiler and superheater tubes because of their high corrosion resistance, high oxidation resistance, acceptable mechanical characteristics at elevated temperatures, and low cost.Sodium hydroxide is injected to neutralize acidic constituents in the steam path, but caustic can concentrate in boiler tubes and attack the surface metal (known as gouging) even traces of caustic in the steam can deposit on surfaces and cause local concentrations of several percent (ASM handbook, 1992). Not only sensitized grains but also sigma phase formed in the weld metal can initiate caustic cracking. In this research, the cause of the failure of 304H stainless steel superheater tubes in a methanol petrochemical plant in Iran was studied with a focus on the effects of caustic embrittlement on IGSCC."

Jan 1, 2012

By K. E. Barnes

"The “Jameson Cell” flotation cell was developed at Mount Isa Mines in the late 1980’s to address deficiencies in our flotation column installations. Early base metal installations had a variable record. The test work and trials showed they made an improvement metallurgically when operated correctly, but performance of the early installations was hindered by a range of operational and maintenance issues. The installations needed to be more robust, and we needed a better understanding of how to successfully integrate the cells into the plant flow sheet.During the 1990’s, Jameson Cells had great success in coal fines flotation and organic removal in SXEW applications, and became the standard in these applications in Australia. These installations improved the cell design and materials of construction and the cell flow sheet design, to make it low wear with self-regulating control, producing good performance with little operator input.These improvements have enabled a fresh look at the use of Jameson Cells in base metals. Recent new installations have shown significant benefits in “hybrid” circuits, that combine the best features of both Jameson Cells and conventional flotation cells, achieving better overall circuit performance in a smaller footprint than either technology could do by itself.Case studies of successful base metal applications are discussed, using size-by-size mineralogical performance to explain the improved circuit performance. The new methods of flow sheet test work design are also described."

Jan 1, 2006

By M. Jahazi, J. Gholipour

Design and manufacturing of parts using hydroforming process require knowledge about material behaviour and tribological effects during hydroforming. Lubrication is one of the key issues in successfully hydroform the tubes. A Ni-based super alloy tube with 50.8 mm (2 inches) outer diameter and 0.9 mm (0.035 inches) thickness is considered for this research to study the effect of lubricants on the formability of the tubes. Hydroforming of a hollow compressor blade is considered for this project. A combination of press forming and hydroforming is employed to produce the part. LS-DYNA, an explicit dynamic finite element code, is used to model the experiments. Different lubricants are modeled using different coefficient of friction in the model. Predicted results for strain distribution at a critical section of the tube are extracted for each case to evaluate the effect of different lubricants on the process.

Jan 1, 2006

By Johnny Zhang, Yang Anguo, Li Weifeng, Xueyi Guo

"SKSTM oxygen bottom blowing smelting technology was developed by SKS-ENFI at SKS Smelter, Hunan in the 1990s to replace the conventional sintering process and thus to meet the high national EHS standard for lead.Since then, two major milestones have been achieved:1. Since 2002, the SKS oxygen bottom blowing smelting-blast furnace reduction has been in operation at SKS, YGL, Chizhou smelter etc. Now in China, about 50% of the lead (4.2 millions t/year) is produced using SKS process; and2. Since 2008, the blast furnace has been replaced by direct reduction of molten rich lead slag at YGJ smelter, which is more energy-efficient since no slag cooling is required. This two stage process (SKS Oxidation- Direct Reduction) is named as the YGL process.Since 2008, numerous technological innovations have been implemented in the furnace design, process control, and maintenance at YGL. The plant has been successfully demonstrated its unique excellent performances on all aspects from processing capacity, product quality, energy reduction, cost reduction and emission reduction. The purpose of this report is to update all the improvements with proven tracks.Meanwhile, a preliminary comparison on the following aspects between the YGL process and other similar technologies has been discussed:1. Plant design and operating conditions;2. Mass and heat balances, metal (Pb, Ag) recovery;3. Consumables, oxygen gun and refractory lining life;4. Energy consumption and operating costs;5. Sulfur capture and emission reduction etc.It is concluded that the modified SKSTM process is a clean SO2-free emission process. The process is characteristic of other features such as no extra fuel addition, low capital with a small foot-print design, low OPEX, high throughput, easy operation, long refractory lining life and high productivity (95%+ on line time annually). It offers an alternative cost-effective technology for lead smelting industry."

Jan 1, 2014

By Marty Hudyma

Large seismic events have been reported in mines in the Sudbury mining camp for more than 70 years. Nevertheless, no detailed record of the events has been compiled. In 2008, the Sudbury Regional Seismic Network (SRSN) research project was initiated to collect more accurate data with regard to the magnitude and locations of mining-induced seismic events in and near the mines in the Sudbury Basin. The data is used to better understand the mechanisms of the events and cause-effect relations between mining and seismic events. Through the collection of a central database of large seismic events, new insight is being be gained into why some mines are much more prone to large events than others. Fifteen low cost seismic stations have been distributed throughout the Sudbury basin. The data from each seismic station is uploaded to a central server using the internet. Data recorded on the SRSN is processed on a daily basis, and a weekly summary of blasts and events is issued to project sponsors. Seismic events smaller than local magnitude +1.0 have been identified and located. Event location accuracy is less than 2 kilometres, however, many events have been located less than 1 km from a mine. The SRSN fills a seismic monitoring gap between the in-mine microseismic monitoring systems and the earthquake monitoring system operated by the Geological Survey of Canada. Since July 2008, more than 600 mine blasts and more than 450 mining-induced seismic events have been recorded in the Sudbury basin. This paper primarily discusses the technical aspects of the design and operation of the SRSN. The SRSN is a Canadian Mining Industry Research Organisation (CAMIRO) research project, with industry sponsorship and support from FNX Mining, Itasca Canada, Vale Inco and Xstrata Nickel.

Oct 1, 2010

By George Rice

Foreword Following the explosion in the Hillcrest mine, which occurred in the evening of Sunday, September 19th, 1926, and in which two men lost their lives, the writer was invited by the Hon. J.E. Brownlee, Premier of Alberta, to conduct an investigation into the causes of the disaster, and to make such recommendations as seemed advisable with a view to minimizing as far as possible the chance of future explosions in this and similar Alberta coal mines. Accordingly, the mine was visited, and extensive investigations were made underground on October 21st, 2.2.nd, and 25th, in company with Mr. John T. Stirling, Chief Inspector of Mines for Alberta, Mr. Moses Johnson, District Inspector for the Crowsnest Pass District, Mr. J as. A. Richards, Inspector of Mines, Edmonton, and also Mr. Thomas Davies, manager, and other officials of the Hillcrest mine. Hearings of the coroner's inquest were also attended on October 20th and 23rd, when testimony regarding the explosion was given by various witnesses. The following paper summarizes my general observations in tracing the place of origin of the explosion, and my efforts to determine the cause of ignition. Certain recommendations arc also made, and the writer invites discussion on these and the other matters dealt with in the paper.

Jan 1, 1928

By John C. Taylor

A resource document, prepared for the Royal Commission on the Health and Safety of Workers in Mines, which outlines aspects of occupational health and safety in the Canadian metallurgical industry has been expanded to provide examples of some practical solutions. General process descriptions are provided in conjunction with some of the major potential hazards associated with each step. Emissions to the working environment, particularly around converters, are discussed. Newer metallurgical processes, the role of automation and other advances in the metallurgical industry are described with respect to their impact on the work place. The role of staff and unit employees in providing safe working conditions in the complex metallurgical plant of today is outlined and the need for close cooperation within the human sector emphasized. The technology is available and is being applied to integrate the complex process requirements with realistic regulations to control emissions and provide a safe, healthy environment in metallurgical plants.

Jan 1, 1978

By H. Marquis

This paper is concerned with an analysis of a number of failures of large-size, hypervelocity light gas gun chambers and barrels. A brief description of the light gas gun principle and of the various types of guns is first given. The failures and the investigations carried out are then described in detail, with the failures divided into two groups. The first group comprises those failures caused by certain conditions to which the guns may be submitted, and includes, for example, severe local heating of the bore surface causing hardening and cracking of the steel. These conditions were accidental and steps were taken to prevent them. The remaining failures were due to faults in the material or in the heat-treatment, manufacturing or assembling procedures. Specific problems, such as hydrogen embrittlement, and the use of high strength gun barrels above their ductile-brittle transition temperature by preheating prior to firing, are briefly considered. Some interesting observations are also presented on the use of surface markings, and angles of fracture of large fragments, as an

Jan 1, 1962

By Karl J. C. Harries

Mineral Agreements and Royalties

Jan 1, 2003

By Gerald Blackmore

"This paper suggests that with the settlement of long-term contracts of fifteen years' duration, with prospects of extension, the coal mining industry has, for the first time, a complete commercial justification for large-scale planning.The labour costs of coal production over past years are analyzed and, with the acceptance of the premise that the basic shift rates are certain to rise in the years to come, the paper suggests that forward planning should provide &r capital investment to make a traditionally labour-dense industry into a capital-dense industry.Automated methods of manpower deployment and timekeeping and the monitoring of all equipment back to a central control point are discussed as ail-important means of obtaining maximum utilization of high-cost capital investment.Principles of payment of the work-force, and the utilization of equipment 24 hours a day, seven days a week and the maximum number of days a year, are dealt with as means of achieving maximum capital utilization. Some of the new technical underground and coal preparation problems which will undoubtedly result from the concentration of workings and maximum machine utilization are discussed, and the author makes suggestions as to how these might be solved.In short, the author predicts that if the coal mining industry is prepared to recognize the problems and invest in modern equipment backed by highly trained staff. then the outcome will justify the high capital investment involved. He stresses the importance of human communications in achieving this end."

Jan 1, 1970

By G. J. Simandl

"Since the 1980s, China has become the predominant producer of REEs. Recently, it introduced REE export quotas and this started a world-scale REE exploration rush. REE resources are concentrated in carbonatite-related deposits, peralkaline igneous rocks, pegmatites, REE ± P veins, ion adsorption clays, placers, and some deep ocean sediments. REEs could also be derived as a by-product of phosphate fertilizer, U processing, Ti-Zr-bearing placers, and exploitation of Olympic Dam-type sub-type of IOCG deposits. The ideal REE development target would be located in a politically stable jurisdiction such as Canada. REE grade and tonnage, mineralogy, and permissive metallurgy are some of the key technical factors that could be used to screen projects. INTRODUCTIONAccording to the International Union of Pure and Applied Chemistry (IUPAC), the term “rare earth elements” (REEs) encompasses yttrium (Y), scandium (Sc), and the lanthanide series: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). This definition is used throughout this paper.REEs are subdivided into light (LREE) and heavy (HREE) categories. LREEs include, Sc, La, Ce, Pr, Nd, Sm, Eu, and Gd and HREE include Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. Promethium (Pm) does not occur in nature. Concentrations of individual LREEs in the upper crust of the Earth are comparable to those of base metals. Even the least abundant REE (Lu) is about 200 times more abundant than gold.The production of REEs, reported in the form of oxides (REOs), for 2011 is estimated at 140 000 t (Figure 1a). Although high technology industries can substitute several REEs with other materials, these substitutes are typically more expensive or less effective than the REEs they replace. A number of countries, including the United States, consider several REEs essential for national security, their economy, and a general reduction in green house gas emissions. The forecasted demand for individual LREOs is much higher than that of HREOs (Figure 2). Dy, Eu, Tb, Nd, and Y are essential for the US economy and subject to predicted supply disruptions (U.S. Department of Energy, 2010)."

Jan 1, 2012

By Thomas Glück

Established and emerging mining companies face significant challenges in managing their operations and projects. Outcomes often do not meet the expectations of all the stakeholders of particular developments. This paper reviews typical management practises used by mining companies to undertake mining projects and improve their operations. A simple application of the House of Quality (HOQ) tool used in the Quality Functional Deployment (QFD) management approach is presented. It is shown that a QFDMMPtg approach could lead to innovation in mining processing plant development practice.

Jan 1, 2015

By R. F. Favreau, L. C. Lang

"In modern blasting technology blasts are designed and analysed on an energy-mass-time relationship. The energy of the explosive is derived by computer analysis and the work potential of the available energy is expressed in numerical values. The mass involved in the blast is determined by the geometry of the blast and by the rock density. Time is also a relevant parameter, because time is required to complete the three basic stages of the breakage process.For successful application of the blasting parameters the basic mechanism of the breakage process must be understood.The physical-mechanical properties of the rock, local structural geology and the thermodynamic properties of the explosives can be brought together to create a computer model of a blast with which it is possible to predict separately the results of each parameter and to express the predicted degree of change in any parameter by actual numbers.A long-range project has started to create a ""bank"" of rock properties for as many Canadian and foreign mines as possible. A computer model has been successfully applied to predicting the effect of varying the ratio of spacing to burden at constant rock volume and significantly improved results are achieved, as the S/B ratio is increased up to about 2 to 2.5.High-speed photography has been applied to determine the time that has elapsed between zero time and the beginning of movement of the mass. The results assist in determining minimum and optimum delay time required for multiple-row blasting.The approach as described in the paper is now well proven and is clearly superior to previous methods based on powder factors and human assessment."

Jan 1, 1972

By C. Droun

"Low back pains account for about 13 per cent of all compensation claims made to the Quebec Workmen's Compensation Commission and cost the employers a sum exceeding ten million dollars. The frequency and cost of these health problems in Quebec metal mines are proportional to the provincial trends. An elaborate review of the literature on the causes, nature and prevention of low back pain is made in this presentation. A prevention program for low back pain has been designed in cooperation with a team of seven medical specialists and two physiotherapists for the Quebec metal mines. The program is especially designed for persons who have had low back pain, in order to prevent a recurrence, and for persons beginning to feel chronic difficulties. It is based on existing programs at the Hawthorne Plant of Western Electric Company and at Minnesota Mining and Manufacturing, but it requires a much different approach because of the nature of medical care available at the mining sites. The program is difficult because it involves a change of attitude for every employee and every supervisor. The program, so far, is beneficial because several men are now seriously engaged in an active program of reconditioning and because the problem of low back pain ie beginning to be seen from a new angle."

Jan 1, 1973

By Shahé Shnorhokian

A study was conducted on the seismic activities and associated rockburst events that took place at an underground Canadian metal mine over a period of five years. In the first stage, a back analysis of the microseismic database led to the identification of clusters of major events. The locations of these clusters were identified with respect to the local geology and the planned mining sequence. In the second stage, a numerical model was constructed using the finite difference code FLAC3D to simulate the in-situ stress, mine geometry, local geology, and stope sequence. Mining-induced stress fields were compared against two rockburst events that took place during this period, as well as against the various geologic units present. It was shown that by combining microseismic analysis and numerical modeling, it was possible to provide a basis for evaluating the influence of the in-situ stress regimes and stope sequencing on mining-induced seismic response.

May 1, 2011

By D. Beneteau, D. Milne

"Advances in technology provide educators with valuable tools to enhance their teaching and efficiently deliver content to larger audiences. University educators are often encouraged to become more “research intensive” and to increase student enrollment. Faced with these pressures, there is a tendency to use technology to improve teaching efficiencies rather than to enhance existing teaching approaches. Practical learning in applied engineering courses would suffer greatly if hands-on experience is not emphasized. This paper discusses advantages and limitations of new technologies applied to learning, and methods to incorporate more hands-on experiential teaching techniques to applied mining engineering courses.RÉSUMÉ Les avancées technologiques fournissent aux éducateurs des outils intéressants pour rehausser leur enseignement et livrer efficacement de la matière à de grands auditoires. Les éducateurs universitaires sont souvent encouragés à devenir plus « axés sur la recherche » et d’augmenter l’inscription d’étudiants. Face à ces pressions, il y a une tendance à utiliser la technologie pour améliorer l’efficacité d’enseignement plutôt que de rehausser les approches existantes d’enseignement. L’apprentissage concret dans les cours d’ingénierie appliquée souffrirait grandement si l’accent n’est pas mis sur l’expérience pratique. Le présent article discute des avantages et des limitations des nouvelles technologies appliquées à l’apprentissage et des méthodes pour incorporer plus de techniques expérimentales pratiques aux cours de génie minier appliqué."

Jan 1, 2016

By S. C. Radopoulou

Pavement condition assessment is an indispensable constituent in maintaining roadway infrastructure. Current practices for pavement condition assessment are labor intensive which introduce subjectivity in pavement rating and are time consuming. Automated methods rely on full 3D reconstruction of the pavement surface which introduces high equipment and computation costs. This paper presents a methodology for detection of patch type distresses in asphalt pavement images. This method uses filtering and histogram equalization for clearing and enhancing the image accordingly. It continues by applying the morphological process of closing, along with some rules based on the characteristics of a patch when captured in an image, to finally detect the area it occupies. Criteria for area, length, and width of a patch as seen in an image are taken into account to decide whether a probable patch is actually a patch. The method has been implemented in C#. The preliminary experiments demonstrate it produces promising recognition results

Aug 1, 2013

By John A. Wells, Leticia Conca, Kenneth G. Thomas

"Since about 2002 there has been significant capital cost escalation, not inflation, in the mining industry causing turmoil for successful project completion. Project capital costs have more than doubled and some cases tripled in this time period. This has rendered many projects to be economically challenged and in some cases not viable. In addition higher than expected operating costs have further adversely affected project metrics such as NPV and IRR. Capital cost increases for projects have been widely reported globally. This current paper reviews three items. Firstly, why such capital increases and the various components that make up capital estimates. Secondly, it looks at reasons why preliminary estimates, for example at scoping and pre-feasibility level, have been lower than the ultimate constructed costs. Such increases and differences in estimates have caused major problems for mine builders and have led to a general nervousness on the part of those providing project finance. Thirdly, what discipline is needed in project execution in an attempt to mitigate such capital increases. The paper will hopefully give a better understanding of the various issues and factors involved for those in the mining industry.INTRODUCTION The years 2012 and 2013 were a turbulent time for the mining industry. The European economic crisis, politics, metal price volatility and a wave of changes of CEO´s in some of the major mining companies all contributed to a challenging couple of years. Two issues stood out. First, the huge increases reported in the capital costs of projects, where increases of 100% - 300% were not uncommon and in some cases exceeded that during the first decade of the 21st century. Second, company write downs related to takeovers during the boom and the stabilization/correction in commodity prices. These have led to great uncertainty, made it difficult (or impossible) to raise project financing costs, contributed to the changes at CEO level and placed many projects either on hold or cancelled altogether. It is commonplace now to read of companies talking of reduced capital expenditure and making a complete review of their projects and operations to contain costs."

Jan 1, 2014

By D. Wolfe, R. Cleminson

"The Aurora North mine has been operating for more than ten years, and is the source of over half of Syncrude’s bitumen production. The slurry systems at Aurora experience high rates of wear, and mission lengths on current slurry pumps are nominally 1500-2000 hours. Recent work has enabled a better understanding of the significant adverse effect of large particle impingement damage to impeller vane leading edges - which is the known life determining issue for Aurora hydrotransport pumps. A new pump design has been developed with a larger diameter impeller and increased vane lengths, and is expected to triple Aurora’s mission length for hydrotransport pumps.INTRODUCTIONSlurry Pumps are Critical Equipment at SyncrudeSlurry pumps are a critical component in Syncrude’s operations. In a typical Aurora application, each pump stage helps move over 8000 dry tonnes per hour of oil sand, plus an equal volume of process water that has been added to create the slurry. The average impeller life in oil sand hydrotransport service at Aurora has been nominally 1500-2000 hours, or 12-16 million tonnes of oil sand pumped. Generally, the slurry pump application at Aurora has proven very difficult to improve due to the unique combination of high sand abrasivity, 125 mm (5”) large particle top size (lumps), and high flow rate relative to basic pump size; a factor that results in higher than optimal impeller vane speeds for the service conditions.PROJECT BASISSlurry Pumps are the Reliability Bottleneck at AuroraSlurry pumps are currently the shortest-lived components that determine the overall system run length at Aurora, in Hydrotransport, Extraction and Tailings. Vibrating screens and piping had been previous bottlenecks, but their reliability has been improved through upgrades in equipment design and wear materials. Both vibrating screens and piping can now achieve 4000 hour mission lengths."

Jan 1, 2013

By E. Van Den Neste

A concise historical review is given of the Overpelt plant and the general principles of zinc hydrometallurgy are briefly outlined, together with a description of the new electrolytic zinc plant ore roasting process and, more particularly, the original Overpelt roasting process. A detailed description of the flowsheet of the zinc electrowinning plant, .with an annual capacity of 100,000 t, successfully put into operation in May 1974, is given. The treatment of the residues is performed following the goethite process ; the purification is continuous in two steps; the tank house is equipped with cells containing jumbo cathodes; the handling and stripping of the cathodes is fully mechanized. Concluding the description, some metallurgical and other features of the project are explained in detail.

Jan 1, 1977