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By H. Scott Swinden

"ForewordA symposium on base metal deposits was held in Bathurst, New Brunswick, from June 10-13, 1990, sponsored jointly by the Geological Surveys Branch of the New Brunswick Department of Natural Resources and Energy, the New Brunswick Prospectors and Developers Association, and the Geology Division of the Canadian Institute of Mining, Metallurgy and Petroleum . Papers prepared for the symposuim are being published as a series of articles in the CIM Bulletin. This second paper (the first was by Fyffe, et al., in Vol. 83, No. 938) in the series presents an overview of the paleotectonic settings of massive sulphide deposits in the Dunnage Zone of Newfoundland with emphasis on volcanic geochemistry.ABSTRACTCambrian and Ordovician volcanic sequences of central Newfoundland, which record the history of the Iapetus Ocean, are prolific hosts to volcanogenic massive sulphide (VMS) deposits. Geochemical, isotopic and geochronological studies show that the vestiges of Iapetus in Newfoundland probably record a complex series of island arcs and back-arc basins that were marginal to, rather than part of, the main ocean basin of Iapetus. The geochemical and isotopic data provide a means of characterizing the tectonic environment of individual volcanic sequences, and allow us to identify a number of distinct tectonic environments in which VMS depositiontook place.Four tectonic environments have been identified as being associated with VMS deposition: (I) back-arc environments hosting VMS deposits include both N-MORB-type ophiolites (e.g. Skidder?) and volcanic sequences with oceanic island (or within plate) tholeiite characteristics (e.g. Great Burnt Lake); (2) primitive arc environments include both supra-subduction zone (SSZ) ophiolites (e.g. Betts Cove, Rambler) and volcanic/epiclastic sequences (e.g. Point Leamington, Duck Pond) and are characterized by abundant arc tholeiites, with lesser refractory lavas and rhyolites; (3) mature arc environments comprise dominantly thick felsic and mafic volcanic piles in the Buchans - Robert's Arm Belt (including the Buchans camp) and are characterized by dominantly calc alkalic basalt and andesite; and (4) continental rift environments occur in the Hermitage Flexure area (e.g. Strickland deposit) and are characterized by dominantly felsic volcanic sequences.Island arc environments are by far the most prolific hosts to VMS deposits. Patterns of VMS distribution in central Newfoundland show that similar tectonic settings may be recorded by very different stratigraphic sequences (e.g. both ophiolites and thick volcanic/ epiclastic sequences may record primitive arc rifting) and emphasize the importance of the rifting in VMS generation, irrespective of the details of the tectonic or stratigraphic setting. The ability to judge the prospectiveness of a volcanic sequence by using whole rock geochemistry to evaluate its tectonic environment may prove useful in area selection at the grassroots exploration level."

Jan 1, 1991

By I. Farr, M. R. Mock, J. C. Robison

"HPAL and POX autoclave vapor-space gasses are vented through an autoclave PCV (Pressure Control Valve). The downstream steam-born mist of liquid droplets and solid particles travels in excess of 1000 m/s with megawatts of kinetic power at temperatures up to 160 C. The characteristics of downstream states often result in problems with corrosion, erosion, noise and vibration. Comprehension of those and related characteristics aids in improved pressure control, overpressure control and autoclave level control. We introduce compressible multiphase flow concepts and constructs germane to such flow including choked flow, continuous phase change, shock waves and supersonic flow plumes. Flow modeling based on first principles quantitatively predicts such flows providing a tool for component sizing and a method to estimate effects of water injection on flow. Insight deduced from modeling aids in mitigation of afore mentioned problems of which we share some from-site examples.INTRODUCTION First principles related to fluid thermodynamics and compressible flow have been employed akin to their application in the rocket industry. We will present the results of the application of those principles conceptually and authentically without mathematical rigour while using language of the pertinent disciplines. The autoclave (AC) vapor space over the slurry of a POX (Pressure Oxidation) or HPAL (High-Pressure Acid Leach) system (depicted in Figure 1) is vented via a PCV (pressure control valve) followed by certain ducting, and perhaps a nozzle, before exiting at atmospheric (typically) pressure. As indicated by its name the PCV controls the AC pressure as the flow control component of a pressure control loop."

Jan 1, 2017

By T. Crivits

"Phase equilibria in the ‘Cu2O’-‘Fe2O3’-SiO2 system, the base slag system in copper production, were recently determined. However, the addition of MgO, commonly present in the slag, drastically changes the phase equilibria in this system. The present study focuses on the phase equilibria in the ‘Cu2O’-‘Fe2O3’-MgO-SiO2 system in equilibrium with metallic copper.Recently, an experimental procedure has been developed that resolved a number of experimental difficulties. This procedure has been successfully applied to characterise several complex industrial copper slags. It includes a high-temperature equilibration followed by rapid quenching and electron probe X-ray micro-analysis (EPMA). The methodology was adapted to the present system and used to determine the liquidus at SiO2 saturation and in contact with high-MgO phases in between 1100 and 1250 °C in Cu2Orich slags.The results indicate a maximum solubility of MgO in the system at 1200 °C of 5 wt%. The boundary line between tridymite and spinel lies 3-4 wt% closer to the SiO2 apex for every 2 wt% MgO added. These new data on the high-copper slags are important for optimisation of the direct-to blister"

Jan 1, 2014

By N. Hosking, M. Nichols

Aluminum alloys are increasingly used for automotive body construction but are susceptible to filiform corrosion or paint blistering in service. Filiform corrosion resistance of two 6000-series aluminum alloys was investigated in this work. Test panels were produced with full automotive coating layers and scribed parallel and perpendicular to the rolling direction. The corrosion exposure comprised an inoculation step with acidified salt solution followed by a 6-week exposure period at 95% relative humidity and either 25°C or 70°C. Greatest corrosion activity was measured on the alloy with higher copper content, AA6111. Higher temperature exposure led to greatly enhanced corrosion activity for AA6111 compared to the lower temperature exposure. The 70°C exposure also led to greater mean corrosion-affected area measurements for the low copper aluminum alloy, AA6022, but the effect was not as stark as that observed for AA6111. Rolling direction affected the propagation direction, and possibly mechanism, of the corrosion effects. Cross-sectional analysis revealed dense corrosion products within the filament, comprising mostly aluminum and oxygen but with traces of chloride and sulphate. Development of varying filament and blister types on a single test panel and the progression of corrosion underneath a filament into the substrate indicate that several corrosion mechanisms can develop on the test panel, testament to the complexity of the corroding surface developed on an aluminum automotive body panel.

Jan 1, 2015

By C S. Beals

The Dominion Observatory was founded in 1905 and, from the beginning, it work included research in both astronomical and geophysical science. During its first years, up to 1916, the Observatory also included geodetic surveying as part of it scientific program. Although, at the beginning of the century, geophysics did not have the close connection with mineral exploration that it now holds , the founders of the Observatory were men of vision, and they laid a solid foundation for the application of the techniques of geomagnetism, gravity and seismology to an understanding of the Canadian terrain of plain , mountains, seacoasts and shield area . The particular sphere which the Observatory occupies in the field of geophysics has been evolving over a period of many years and it has now a rather definite relation to the work of other government bodies, university science departments and industrial organizations. We have, for example, an over-all responsibility for the regional magnetic mapping of Canada and, as the magnetic field is subject to slow but steady changes, we produce new magnetic maps of the country every five years. These maps indicate the strength and direction of the magnetic field, the variation of the compass and the rate of change of the magnetic elements.

Jan 1, 1963

By M. L. F. Paullo, S. Cristian Mejia, D. Roehl

"Rock fracture simulation most often presents non-linear behaviour due to loss of material integrity and strain concentration in the fracture zone. These strains generate local instabilities that propagate to the global system of equilibrium equations, generating convergence problems of the numerical solution. Often, in such cases, analyses in the post-critical regime are unfeasible. To overcome the numerical difficulties associated with problems of stiffness loss in the post-critical regime control methods, also called continuation methods, are employed. Among them are the arc-length method, the energy control method and the indirect displacement control method. These methods are employed in conjunction with a Newton- Raphson scheme for the solution of non-linear systems of equations. However, depending on the system instability, convergence in not guaranteed even with very small increments. In the present work these control techniques are investigated in combination with cohesive elements to simulate rock fracture. The constitutive model employed with the cohesive elements represents stiffness degradation through a damage law, which leads to serious convergence difficulties as reported in the literature. Here the continuation methods mentioned are applied to a Mode I rock fracture problem and to hydraulic fracture simulations. The effectiveness of the different continuation methods is compared.INTRODUCTIONThe process of rock fracture induced by the fluid pressure is called hydraulic fracturing. The propagation of a hydraulic fracture is a complex process, which is basically defined by the mechanical deformation of the rock, the fluid flow within the fracture and the fracture propagation itself (Mokryakov, 2011). In the works of Bendezu et al. (2013), Chen (2012) and Carrier et al. (2012), vertical hydraulic fracture propagation is modeled by cohesive elements with traction-separation law. The softening behavior of rock in post-critical regime is demonstrated by experimental testing and is characterized mainly by high strains and low stresses (Crowder and Bawden, 2004). This nonlinear behaviour can arise due to material nonlinearity, such as micro-cracking and damage, leading to softening behaviour (Chandrakant, S.D., 2012). The cohesive fracture model considers in its formulation the softening behaviour that most rocks present in post-critical regime with propagation criteria."

Jan 1, 2015

By S. Kivrak

The firms in construction industry could not sufficiently adapt the rapidly emerging information technologies in recent years into their corporate structures. Therefore, in an effort to further exploit the benefits of information technology (IT), integration of the experiences and backgrounds of construction industry and the advantages of IT, is one of the most open-ended fields for improvement in this industry. Utilization of IT in the construction sites will positively affect the efficiency, productivity, quality and health & safety issues in the construction sites thus the cost and completion time of the projects. Within this context, augmented reality technology, which brings a new perspective into IT, can be put into the service of construction industry. Augmented reality which has been designed to improve the services in many application domains such as school education, military warfare, military trainings, industrial maintenance, retail and medical, can be defined in the simplest form as augmenting the real world with information from the virtual world. The main aim of this study, which presents an overview of an ongoing project, is to develop an innovative method by making a construction worker, foreman, equipment operator or a site engineer watch a very comprehensive and informative animation which will enable the said staff to perform or supervise all the phases of the activity he or she is in charge for in a more efficient, productive, safer and qualified manner by means of smart glasses using augmented reality systems. In this respect, training material related with the activities in the construction sites will be prepared and with a well-fictionalized scenario, animations exhibiting all the phases and details regarding the related activity (e.g. masonry, formwork and rebar works etc.), method of statement, correct and incorrect applications in comparison-wise manner, will be produced. Therefore, the user will be able to reach the training material, method statements etc. in the animations about the activity he or she is in charge for, enabling him or her to figure out the work as prescribed in the specifications. Basic trainings about the system will be given to target group, i.e. construction workers, foremen, operators, site engineers and managers working in the construction sites to apply the system on sites after all the system was tested. After the testings, to determine the effectiveness of this system, semi-structured interviews and survey questionnaires will be conducted among the mentioned target group. Therefore, the potential benefits of this system to the construction industry can be determined. The main target of this study is to implement an efficient, thorough construction management by orienting the staff in the construction sites to perform efficient, safe and qualified works by means of smart glasses that use augmented reality. There are relatively few studies about the implementations of augmented reality technology in construction. The outputs to be attained in the end of the study have the potential of improvement of time, cost, quality and safety parameters by ensuring a qualified, safe, efficient and productive construction management via augmented reality technology in the construction industry.

Aug 1, 2013

By Adam J. Szladow

"INTRODUCTIONThe low calorific value and the high moisture and ash contents of run-of-mine (r.o.rn.) lignite limits the utilization of Saskatchewan lignites to thermal power plants in Saskatchewan, Manitoba and western Ontario. On the other hand, the low sulphur content and the low mining cost make lignites potentially attractive for new coal markets, if suitable processes can be found for upgrading. Economic upgrading to a higher quality fuel would make lignites more acceptable for industrial and utility boilers.This paper presents a summary of the process engineering evaluation of coal upgrading technologies conducted in support of a study of selected lignite upgrading processes. The summary presents the relative advantages and offers specific comments on the application of coal upgrading technologies for lignites. ResourcesLignite comprises the largest fossil fuel energy deposits in Saskatchewan. The total resources of immediate and future interest exceed 27 billion tonnes. The measured and indicated lignite resources of immediate interest are large enough to last for over 200 years at the current production rate of about 10 million tonnes per year (Table 1).Saskatchewan lignitedeposits are present in three different geologic formations: (I) the Ravenscrag Formation of Paleocene Age in southern Saskatchewan; (2) the Swan River Formation of Lower Cretaceous Age in central north Saskatchewan; and (3) the Judith River Formation of Upper Cretaceous Age in central west Saskatchewan. The deposits in the Swan River and Judith River Formation are not currently of economic interest.The Ravenscrag deposits are confmed to four lignite basins, namely: the Estevan, the Willow Bunch, the Wood Mountain and the Cypress basin (Fig. 1). The estimated resources of immediate interest in the four basins are over 7 billion tonnes (Table I). These resources include lignite seams at least 1.5 m thick, at depths of less than 45 m.The average quality of lignite varies relatively little between the four basins considering the distance between deposits (Table 2). There is, however, a progressive increase in moisture and ash content, and a decrease in calorific value and carbon content as one moves westward from the Estevan to Wood Mountain and Cypress basins. The Estevan area deposits are of higher rank despite the fact that they are stratigraphically younger than the Willow Bunch deposits (Cameron and Marconi, 1979).In upgrading lignite to a higher quality fuel, it is important to know not only the average proximate and ultimate analysis (Table 2) but also other lignite characteristics influencing the product quality . For example, Figure 2 shows the effect of lignite HIC ratio on the product equilibrium moisture for hydrothermal treatment of lignite. It is apparent that lignites with a higher HIC ratio, or high liptinite content yield much better quality product for the same hydrotreatment conditions. Other examples of lignite characteristics which are important in upgrading include distribution of sulphur forms and mineral matter, maceral composition and degree of surface oxidation."

Jan 1, 1989

By M. Zanini, D. Wong

ABSTRACT: Metals market improvements in 2005 drove the desire to increase nickel throughput and the production of nickel oxide sinter at the Vale Ltd. Copper Cliff smelter. Significant difficulties were encountered due to the unreliable quality of Bessemer matte being produced. Concentrate feed changes and the loss of technical and operational expertise during the previous market downturn contributed to the challenge of making the required improvements. Significant progress has been made in the converter aisle by focusing on employee engagement and standardizing best operating practices for a new generation of skimmers. This paper documents these initiatives and seeks to balance the art and science of converting.

Jan 1, 2012

By Paul B. Batten

Shutdown is a generic term for what may be called an Outage, Turn Around (TAR) or Overhaul etc. Running a plant shutdown well has always been key to the financial contribution of a mine. However, something important has changed. The post pandemic reality is that it is harder to retain workers and many of those near retirement just didn’t come back to work. This is creating a shortage of experienced people and a workforce that changes employers easily. We are seeing the impact of this manifested in the erosion of established maintenance and supply chain processes that now struggle to yield the plant runtime that could once be taken for granted. The scope, cost and duration of a shutdown varies widely depending on the nature of the work and the equipment being renewed. The PM of an electric shovel might require a week of downtime and cost $100,000. A gold plant may need to go down for 3 days when its time to change mill liners and cost $500,000. A turnaround in a refinery can take more than a month and cost multi millions. Despite the huge differences.

Jan 1, 2023

By F J. Pearce

The Steel Company of Canada, utilizing the S-L process, has produced partially and highly reduced pellets for use in the blast furnace. Experimental blast furnace tests, using reduced pellet burdens, have been carried out. The changes in production rate, fuel rate and general performance of both the S-L and the blast furnace processes are indicated. Introduction T HE ore burdens for a blast furnace may be improved in two ways: chemically, by concentrating the ore to a high degree of purity; and physically, by agglomerating or closely sizing the ore particles. Today, many b1ast furnaces are charged with closely sized agglomerates, some of which contain upwards of 66 per cent iron. The further improvement of these burdens by chemical concentration may, in many instances, be uneconomic due to the large losses of iron that occur during processing. Assuming that it would be possible to reject all of the gangue minerals, the maximum level of concentration of iron in the hematitic ores would be only about 70 per cent.

Jan 1, 1964

By S. S. Burns

"AbstractShovels of 18 cubic yard capacity and larger are described which incorporate advanced technology and techniques providing performance and operation tailored to meet the needs of open-pit mining.To achieve the goal s of increased production at lower cost with consideration of maximum availability, lower energy consumption per ton and low •impact on pit power, Harnischfeger Corporation developed a solid -state drive system (""Electrotorque"" - P&H trademark) and applied unique transmission methods.To date, more than 250,000 hours of experience in different parts of the world under varying operating and environmental conditions has proven that the ""Electrotorque"" shovel is the shovel of the future, today.This paper will discuss the electrical features and touch briefly on some mechanical features.Introduction to ""Electrotorque""THE hoist, crowd, propel and swing machinery of an electric mining shovel are driven by direct-current motors.A D.C. motor is used instead of an A.C. motor because the torque output per ampere input is at a maximum and the fact that it is doubly-fed (armature and field ) provides optimum flexibility in control.The power that is available in the pit is alternating current power. It is therefore necessary to change or convert this A.C. power to D.C. power so that the D.C. motors can be used."

Jan 1, 1977

By T. E. Wakefield

"Final Galloway (stage) designs for vertical drill and blast shaft sinking projects evolve from complex thought patterns which integrate operational processes, systems and methods of communication, power supply, drilling, blasting, ventilating, mucking, supporting, surveying, dewatering, sealing, concrete lining and shaft furnishing. Attention to ergonomic design detail at the shaftsman / structure interface is at the heart of safe and successful multi-deck working platforms. For economy the end product must have a low mass to reduce suspension rope end loads to be able to use smaller suspension hoists and have lighter headframe structures, be robust to withstand concussion damage, be easily constructible on site, be maintainable in the shaft barrel, and comply with safety and legislated standards. This paper’s ambition is to describe a systematic design framework and sequenced thought process that delivers a product that is engineered with excellence, illustrated by making use of two designs that evolved during recent Galloway projects, one destined for a large diameter man/material shaft, the other for a ventilation shaft. The stage engineering iterative process starts with mapping permanent and sinking hoisting layouts, followed by laying out horizontal deck plans, mostly constrained by the permanent shaft purpose and configuration, whilst maximizing openings to enable muck to be removed rapidly for the best sinking cycles. Concurrently the designer needs to understand the chosen sinking methodologies in conjunction with crewing to determine the number of decks and fix their spacing. Insufficient access to move and line up formwork, set reinforcing rods and pour concrete in the confined spaces of the stage is an inherent major risk to be mitigated. An iterative and integrative process follows for the primary configuration which delves into increasing design detail, accommodating all other methodology influences, resulting in 3D layouts for further risk assessment, review and fine tuning by seasoned shaftsmen. INTRODUCTION Documented colliery shaft sinking practice from the late 1800’s makes reference to purpose built walling (bricked lining) cribs with floors suspended in sinking shafts, thereby allowing shaft lining to proceed concurrently with the excavation. Improvements were made by Sir William Galloway who introduced two decks supported at the corners by angle irons. The sinking stage, or Galloway, has developed substantially over time to be the in-barrel heart of the sinking operation, with overwhelming complexity for those who have to design one for the first time."

Jan 1, 2019

By F. M. Clement

British Columbia, unlike the Prairie Provinces, cannot lay claim to vast prairies. She can, however, claim many valleys, uplands and plateaus that are capable of marked agricultural development. It has been said that British Columbia is not an agricultural province. This may or may not be true, but at the present time agricultural production in this province stands second only to that of forestry. The industry has advanced from a total production of 8 millions in 1908 to a total production of 60 millions in 1924, a total increase of approximately 650 per cent in 16 years. In the last 10 years production has increased from 30 millions to 60 millions. No other industry can point to such a rapid development. In 1908 British Columbia imported 12 million dollars worth of foods compared to the 8 millions which were produced at home. In 1924 she imported 20 million dollars worth of foods compared to the 60 millions worth produced at home. In addition we exported foods to the value of approximately 10 million dollars. British Columbia is therefore self-sufficing in-so-far as values ar.e concerned except for approximately 10 millions of dollars. It is not to be expected that this province will ever grow all the coarse grains that she may require: these, along with certain meats, will always be a heavy item in the imports. We are concerned at the present time more with the value of the products than with the quantities produced: in other words, with quantities only in-so-far as ? quantities improve value.

Jan 1, 1925

By F. Vagnon, A. M. Ferrero, M. Pirulli, A. Segalini

"The topic of this study is the design of flexible fences to mitigate the risk due to debris flow phenomena by means of theoretical and experimental studies analysed in framework of the Rock Engineering System (RES).The study of the interaction between debris flows and flexible barriers is a major challenge since many different aspects concerning both the slope characteristics and the structure features are involved. Debris flows are often triggered by the mobilization of debris deposits that are generated by rock fall of adjacent rock walls. The rock debris deposits are difficult to be characterized by the physical and mechanical point of view due to their large variability in volume distribution and, moreover, when dealing with high mountains environment, they are also strongly affected by the presence of water at different phases (solid or liquid) depending on the temperature. The debris deposit turns unstable in relation with the geotechnical and environmental features of the areas and the instability evolution in high mountain steep valley is often a debris flow. Debris flow destructive potential is very high and protections are often needed to reduce the debris flow risk.This complexity determines the needs of comprehensive study able to include the global basin dynamic and the environmental conditions. An a-priori analysis of the influence of the different aspects can be useful to focus on the real driving aspects of the problem. Due to the complexity of the system the application of the RES methodology is recommended in order to clearly define the different assumptions needed, their influence on the simulations and a comparison among them.RES allows investigating triggering criteria, flow and depositional processes and interaction of flows with protection fences in a rational way. For this purpose, an interaction matrix is created: it summarizes the key geotechnical parameters that influence debris flows, their interactions and debris/engineering protection opera behaviour. The goal is to quantify the diagonal-off terms to assess the residual risk after barrier construction, using back analysis from real debris flow event and data collection from literature.This methodology is applied to analyze a debris flow event in the Italian Western Alps where numerical analyses are carried on to assess flow characteristics to be used for fence design through the application of an analytical and numerical model developed by the authors (Brighenti et al, 2013). In particular, the velocity and deposition heights have been estimated using the numerical code RASH3D (Pirulli, 2010), which is a single-phase model based on depth-averaged Saint Venant equations. Pathways of different lengths are studied to assess the input data necessary to design the protection barrier and to determine the associated risk. Simulation of the barrier at different places along the valley will also allow to determine optimal barrier location in terms of minimum residual risks by comparing the velocity, the volume and the energy of the debris after the barrier impact.The work will produce a possible design scheme to be adopted in this environment."

Jan 1, 2015

By Louis R. Bernier

Since 1978, most systematic studies of AMD passive treatment with limestone drains (LD) have dealt with coal mines in the United States. The authors present in this paper the first results of a triennial study initiated in 1999 on the performance of LD installed at the Ni-Cu Lorraine old mine site in Temiscamingue during a remediation plan that involved the installation of a cover with capillary barrier effects (CCBE) over the reactive pyrrhotite-rich tailings. Typically, a LD is a trench enclosed by impervious materials filled with crushed limestone and may be oxic or anoxic. Four LD (one filled with marble and 3 with dolomite) were installed at the Lorraine site. The LD have been in operation since May 1999 and are performing differently. The most contaminated mine effluent flows south and is directed towards 3 LD filled with crushed dolomite, while a 4th LD was filled with crushed marble and installed west. The LD filled with marble has been generating maximum alkalinity since the beginning of the passive treatment. Two of the dolomite drains have been generating alkalinity since mid-summer 1999, but one is not, even if a substantial pH raise was observed. A pH above 5.5 is required usually for the dolomite drains to start generating alkalinity. The installation of LD at the Lorraine site contributes significantly to the reduction of metals and sulphates loading.

May 1, 2001

By M. Kreuh

An investigation of the pressure pulse spectrum generated by the gas dispersion processes in a Peirce Smith copper converter was undertaken via the simultaneous measurement of four tuyeres using high frequency pressure transducers. The data was captured, stored, and analyzed using digital data processing techniques; including power spectral density plots, band-pass filtering, and a principal component analysis (PCA). The process was characterized throughout by a dominant 3 Hz pulse signature attributed to the formation of lateral gas envelopes. In particular, test tuyeres in the tuyere line tended to operate synchronously at the dominant frequency, regardless of operating conditions tested and despite being distributed along the converter. Synchronous behavior is thought to arise from the acoustic coupling and possible resonance behavior of the gas delivery system on the converter.

Jan 1, 2007

By R. H. Chambers, L. Alderman

"The paper is introduced by an examination of the factors which have led to the present world-wide interest in charging preheated coal to coke ovens. Various possible methods of preheating and charging the coal are considered and reasons are given for the adoption of the methods chosen. The design of the pilot preheating plant for the British Coke Research Association is discussed and its influence on the design of the commercial units for the South African Iron and Steel Corporation's plant at Pretoria and the British Steel Corporation's plant at Beighton are explained. Operating procedures on the pilot plant are described, particularly with regard to the charging of the preheated coal. Design features of the commercial installations, engineered by Simon-Carves Ltd., are explained with emphasis on the built-in safety of the control system of the preheating plant, and the particular problems associated with the erection of such plants on working coke oven batteries. Commissioning and operating procedures are described and the problems associated with the integration of the preheating plant into the normal pushing schedule of the plant are discussed. Preliminary operating results with regard to the effect of preheating on coal throughput on the commercial plants and on the properties of the coke produced are given."

Jan 1, 1972

By Rakesh Kumar, Rajabrahma K., A. K. Verma, V. Mukesh

"In this study, laboratory investigation as well as numerical investigation is carried out to ascertain the transition from one mode to another for Semi-circular bend setup. Laboratory investigation is carried by varying the span length (s/2R); crack length (a/R); notch angle (a); and notch thickness (t). The specimen consists of cement, sand and water mixture in a ratio of 1:1:0.5 by weight and are prepared as per the ISRM standards (2014). Tests are conducted by a servo controlled universal testing machine at a strain rate of 0.2 mm/ min. The results are collected in terms of failure load, crack mouth opening displacement (CMOD) and images of crack initiation and propagation.Image analysis of laboratory tested samples shows that crack initiates at the notch tip when the notch inclination angle is 0°. As the notch angle increases (i.e. 30° and 60°) the fracture begins to initiate behind the notch tip. The direction of crack propagation in front and back side of the sample is same for notch inclination angle is 0° whereas it differs more and more as crack inclination increases. The transition represents the change in mode of failure from mode I (0°), mode II (30°) and mixed mode I/II fracture (60°).Finite element method used to find the transition based on MTS failure criterion. The inclination of notch is varied like 40, 42, 44, 45, and 50 deg and FEM analysis shows that the transition from mode-I to Mode-II take place at 49 deg. The same procedure can be extended to find the transition from mode-II to mode-III."

Jan 1, 2015

By S. S. Al-Thyabat, A. M. Ghrair

"Printed circuit board (PCB) is the main part of any electric or electronic device, providing mechanical support and electric connection for the board eclectic components such as capacitors, resistors, diodes etc. PCB consists of non-conductive substrate overlaid with one or more layers of copper sheets. They also contain appreciable amounts of base metals (copper, nickel, tine, and aluminum) and precious metals (gold, silver, and rare earth elements (REE)) which end up in the landfill at the PCB end-of-life.PCB recycling E-waste in general is a profitable business; many valuable raw materials, precious and base metals, can be extracted with high purity. Approximately, one metric tonne of PCBs may contain 80-1500 g of gold and 160–210 kg of copper. The precious metals recovered from PCBs occur at concentrations higher than commercially mined minerals. Also PCB recycling is very important to our environment since many heavy metals (e.g. lead) may be leached from the landfills to the underground reservoirs. In Jordan, however, the work conducted on E-waste and PCB recycling in particular is limited; currently most of the E-waste is either exported or dumped in the landfill.In this work, a combination of physical (magnetic separation), physicochemical (flotation), and chemical methods (leaching) were used to compare metals concentrations in leach liquors produced from a concentrates resulted from a combination of these methods. It was found the leach liquor of the magnetic fraction of the PCB coarse size gave the highest concentration of Fe, Al, and Ni while concentration of Cu was higher in leach liquor of nonmagnetic sink fraction. On the other hand, metals concentration almost similar for both sink and float of the fine size fractions, indicating even distribution of metals concentrations in the fine size fractions."

Jan 1, 2016