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By Hani Henein, J. Barry Wiskel

"The easy accessibility and power of the PC, as well as the education of our engineering students in the use of these tools, are compelling reasons for developing computer aided instructional (CAI) tools. There are a wide range of areas in the engineering curriculum where students must learn the steps and the process of applying judgement in problem solving. In the typical course instruction, · an instructor introduces theory to students; the application of the theory to solving problems is often demonstrated in the abstract. Students therefore spend a significant amount of time learning how to apply the theory to problem solving. Additional time and effort must then be spent to get students to the point of learning concepts and integrating this knowledge. A number of computer aided packages have therefore been developed for use in several courses in the materials science and engineering curriculum that encompass both calculational and instructional capabilities. This paper presents an overview of some of these packages which include the solution of a non-linear equation, the instruction of binary diffusion couples, an introduction of crystallography, an introduction to heat transfer and the solution of thermodynamic stability diagrams. The context in which these CAI Tutorials were developed and are being used will be discussed. The pitfalls in the development of these packages will also be discussed. The use of the tutorials has important implications on the expectations from an engineering education of both instructor and student.IntroductionTraditionally, it is quite routine to teach engineering students how to use a computer (the PC today for undergraduates) as a tool in performing engineering calculations or in simulating a process or a unit operation. This often takes the form of one course in computer programming, whether it is Fortran, Visual basic or a spreadsheet, and another course in numerical computation. However, the materials and electronic revolution have brought about considerable advances in computer power and speed, and accessibility. Today, the manipulation of digital images, movies, and speech are commonplace on a desktop PC.' Many mathematical models that were executed only on workstations can now be readily handled on a PC. Concurrently, more of our students own a PC even if their curriculum does not require them to purchase one. Today, virtually every university student has been introduced to the PC in either their elementary or high school education. Hence, the increased capabilities and accessibility of the PC and the familiarity of students with this tool make it compelling to explore its use as an educational tool for our engineering students. This is not a traditional role of a computer in our engineering curriculum."

Jan 1, 2000

By J. W. Holzenthaler

Teams continue to play a major role at the Phelps Dodge Mining Company El Paso Operations, especially during the present time of low copper prices. The El Paso Operations' teams have taken the initiative during this copper market downturn and have helped reduce operating costs significantly. Because of this, Phelps Dodge El Paso Operations has continued to grow within the team process by creating a total, non- exempt salaried workforce. In the last year alone, the El Paso Operations have implemented three major initiatives to accommodate the team process. The first was the creation of "guiding principles", a policies and procedures handbook. Second was the "zero and beyond" safety initiative. Third was team compensation. In addition, the Copper Products Company has now adopted a work-team environment, following the lead of the refinery.

Jan 1, 1999

By Chi Ru?an

Sollutions of ammonium chloride, nitrate and sulfate were studied in extraction of rare earths absorbed on a low-grade, kaolilnitic ore recently discovered in southern China. The results of percolation leaching tests and the recovery of the rare-earth values from these solutions are presented.

Jan 1, 1989

By V. A. Bryukvin

A hydroelectrochemical technology has been proposed and experimentally proven for processing metallic gold- and silver-containing concentrates on the basis of copper and copper alloys obtained as a result of preliminary physico-mechanical upgrading of electronic scrap. The proposed technology is based on hydroelectrochemical leaching of scrap using reversible electric current and diluted nitric acid solutions, containing complexing agents, permitting complete separation of gold from the nonferrous matrix without involving gold in the process, and dissolving copper, zinc, lead and tin virtually without any emission of nitrose gases.

Jan 1, 2006

By Chia-Fu Chang

We revise the applicability of the theory of self-organized criticality (SOC) to the process of magnetic relaxation in type-II superconductors. It is demonstrated that the driving parameter of self-organization of vortices is the energy barrier for flux creep and not the current density. Power spectrum of the magnetic noise due to vortex avalanches is calculated and is predicted to vary with time during relaxation.

Jan 1, 2006

By C. Allen

A series of zinc chloride electrowinning tests was carried out in a laboratory scale cell to evaluate the effect of temperature, current density, electrolyte composition, gas sparging and additives on the performance of the cell with respect to current efficiency, voltage, specific energy consumption and deposit morphology. The anode material was DSA for chlorine evolution and the cathode was made of aluminum. At 400 A/m2 current density, a current efficiency of 90.9%, a voltage of 3.4 V and an energy consumption of 2.78 kWh/kg were observed. Air sparging was found beneficial but was not pursued for health and safety reasons. Various additives in the same chemical family as tetrabutyl ammonium chloride (TBAC1) were tested. Both TBAC1 and tetrabutyl ammonium bromide were found to be equally effective. Attempts to carry out the electrolysis at 1200 A/m2 were not as successful.

Jan 1, 2000

By Jiann-Yang Hwang

The economic growth in new developing countries such as China and India has stimulated strong demands in basic materials such as steel. World steel production has exceeded the milestone of a billion tons a year recently. However, the blast furnace technology, which was invented in 1340 A.D., is still the fundamental route for today?s steel production. It is important to develop a new generation of steelmaking technology that can meet the society?s needs from the energy, environmental and economic standpoints in the 21st century. The new microwave and electric arc heating technology discussed in this paper provides a totally different mass and heat transfer mechanism from the conventional blast furnace technology and offers a great potential to meet our society?s needs.

Jan 1, 2006

By Michael L. Sorokin

The metallic nickel production by converting of nickel matte is analysed from the thermodynamic point of view using earlier developed thermodynamic models for sulphide, metal and slag phase. Three-suffix Margules equations are used to calculate thermodynamic properties of melts. Potential diagrams of Ni-FeS-OSiO2 system are calculated for various temperatures and Fe to Ni ratios. The diagrams used for consideration about possibilities of the direct one-stage metallic nickel production.

Jan 1, 1995

By Donald R. Sadoway

Fused salt electrolysis is used extensively in the primary extraction of metals (electrowinning), in the refining of metals (electrorefining), and in the formation of coatings (electroplating). In the case of rare earths, fused salt electrolysis competes with nonelectrochemical processes to make the same products. However, fused salt electrolysis has the potential to produce these metals in a variety of technologically useful forms: thin films and epitaxial layers, powders, and a variety of nonequilibrium structures. The theory and practice of fused salt electrolysis as it applies to the extraction, refining and plating of rare earth metals are described. The potential of fused salt electrolysis to synthesize advanced materials containing the rare earth elements is assessed.

Jan 1, 1989

By H. Aminian

Copper electrowinning (EW) is an important process in connection with the solvent extraction to produce pure and marketable copper cathodes. A phenomenological model was developed to simulate the copper electrowinning process. The simulator is used to predict the operation of the Mines Gaspe pilot plant electrowinning cells put in operation in 1996. Results confirm the potential of the simulator that would subsequently be used for student training, process optimization and assessing the performances of control strategies.

Jan 1, 1999

By L. A. Barta

A new process for the leaching of chalcopyrite concentrates has been developed and tested in miniplant campaigns and locked cycle testwork carried out between 1996 and 1999. The process involves pressure leaching in a sulphuric acid solution, e.g. raffinate from copper solvent extraction. Iron in the feeds is precipitated predominantly as hematite in the autoclave, simultaneously with copper extraction. Gold and silver in the pressure leach residue are recoverable by conventional cyanidation, following flotation to remove elemental sulphur by-product. The results of recent miniplant tests and batch locked cycle tests are provided.

Jan 1, 1999

By Jean-François Domgin

This paper aims at presenting numerical results showing the impact of different parameters on the limitation of entrained slag from ladle to tundish during the ladle drainage. These parameters are process parameters, slag properties or external actuator acting directly on ladle slag behaviour. Numerical simulations based on the use of the CFD Fluent software illustrate the vortexing and non-vortexing phenomena appearing during the ladle drainage. This numerical tool validated by experimental data acquired on water model has been applied to industrial configurations. It shows that the slag properties (viscosity, surface tension?) or some modifications of parameters (slide gate opening, geometry of the ladle bottom?) have a positive effect on the slag entrainment and also on the decrease of the ladle heel. Finally, the modelling of the behaviour of an external actuator injecting some gas in the region of the nozzle reveals interesting possibility for reducing slag entrainment from ladle to tundish during the final steps of the drainage.

Jan 1, 2006

By Corby G. Anderson

Today, with a stringent economic and environmental climate prevailing in the copper business, there is increased interest in evaluating new processing alternatives for production. Hydrometallurgical pressure oxidation of copper concentrates is one of the more viable approaches and several technological candidates have emerged. Of these, an overlooked but industrially proven methodology utilizing nitrogen species catalyzation in the oxidizing pressure leach system may prove to be a feasible process alternative for the future. In this paper, the history of the system and its application to chalcopyrite concentrates will be outlined. In particular, a methodology for effective treatment of precious metals bearing chalcopyrite concentrates via partial oxidation at low temperatures and pressures will be discussed. Finally, the perceived economics of this unique industrially proven process will be delineated.

Jan 1, 1999

By Takeshi Yoshikawa

For the development of low-cost silicon refining process for solar cells, the present authors have been studying the low temperature refining technique, ?solidification refining of Si with Si-Al melts at 1173 ? 1273K?. In the present work, we have investigated the B removal in that refining, utilizing the segregation effect and also the effect of Ti addition to the melt. Segregation ratio of B between solid Si and Si-Al melt was measured by the temperature gradient zone melting technique and it indicated the B removal fraction would be as much as 90%. Titanium addition to the melt was found to produce the TiB2 precipitation with soluble B in that melt and bring the effective B removal of refined Si to its content of 1ppma.

Jan 1, 2006

By Henry Freiser

For the last several years, a systematic investigation of the equilibrium extraction behavior of selective tervalent lanthanides with representative chelating extractions of a variety of chelating agent families has been undertaken for the purpose of learning how to obtain chelating extractants of improved selectivity for separating individual lanthanide ions. The equilibrium extraction data (expressed as log Kex) for each reagent system are linearly related to the reciprocal ionic radius of the tervalent lanthanide ions. The role of adduct formation, steric hindrance, as well as the nature of the bonding atom in the chelate ring, represent some of the factors affecting selectivity arising out of our database of over 200 individual extraction systems, which will be discussed.

Jan 1, 1989

By Pradip

The selective adsorption of chemisorbing fatty acids at high temperatures together with the addition of soda ash and lignin sulfonate as depressants is the key to the industrial processing of bastnaesite ores. This paper presents the results of a fundamental investigation that indicate that alkyl hydroxamates can be an alternative collector for the beneficiation of bastnaesite ores that contain barite and calcite as the principal gangue minerals. The primary mechanism for providing sites for the chemisorption of hydroxamate on bastnaesite appears to be through dissolution of cations, formation of the respective hydroxo complexes and readsorption at the interface.

Jan 1, 1989

By Malcolm J. Harrison

The problems associated with the flow control of abrasive slurries and solids laden fluids creates reliability problems in many mining operations. Conventional valves such as pinch, knife gate and plug types cannot always function reliably in such harsh operating environments. Due to the technological advances in the hard coating industry, ball valves can now be produced with internal surfaces protected from the erosive effects of these applications. Pressures well in excess of the capability of conventional 1000 kPa working pressure valves can now be handled reliably. The significant advantages of minimizing down-time and lowering maintenance costs can now be realized with metal seated ball valves.

Jan 1, 1999

By Peter J. Hancock

The pyrometallurgical .processing of non-ferrous, complex materials and wastes will be surveyed. Pyrometallurgy offers the most versatile way of processing a large variety of such materials because of its high temperatures, closely-controlled oxidation potential and the availability of commercially-proven reactor configurations. Some current industrial applications will be reviewed and possible new applications as well as future trends will be outlined.

Jan 1, 1994

By L. N. Ertzeva

The process for thermal treatment of current pyrrhotite concentrate in reducing environment with the use of disperse metal iron as an iron-bearing additive (optimal volume 20-30%), with downstream magnetic separation of the calcine, has been studied. The reduction process has been performed in conditions emulating those of both tube and fluidize-bed furnaces.

Jan 1, 2006

By David B. George

In spite of the many well-known problems inherent in Pierce-Smith converting, it remains the dominant copper converting process. Continuous copper converting and direct concentrate to blister smelting have been commercially available for over 25 years and now produce approximately 15% of copper smelter production. The two fully commercialized continuous converting processes, Mitsubishi MI Process and Kennecott-Outokumpu Flash Converting, and several emerging converting processes are reviewed with view of their potential, limitations, and environmental performance. Some myths regarding these technologies and Peirce-Smith converting are also challenged.

Jan 1, 2002