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By J. M. Toguri

The viscosity of the molten FeO-Fe2O3-Si0z system in the composition range of interest to copper smelting has been investigated using a rotating cylinder technique. The silica content of the slag was varied from 20 to 35 wt percent while the oxygen pressure of the system was varied from 10-7 10-11 atm. The temperature range investigated was from 1200 to 1350°C. It was found that the viscosity of the slag generally decreased with increasing temperature and increasing oxygen pressure. As the silica content was increased, the viscosity was found to increase.

Jan 1, 1976

By Dai Yongnian

"The feasibility to vacuum distillation of a crude metal or an alloy was discussed. The equilibrium relationship between vapor phase and liquid phase in A-B system - - - - - PA/PB =BAa*/b has been derived. The separation coefficient, BA = rAPA/(rBPB) is a judgment criterion. By calculation PA/PB, the equilibrium composition diagram of vapor phase and liquid phase was drawn. By use of the equation derived by M. Olette, the relationship among the volatilization amounts of various impurities in a crude metal (yi) was further solved. 1-(X/100)= C =(1-Y1/100)1/02i . From yi value obtained in practice, 2i, Pi and then can be calcu-lated. The correct volatilization order of various impurities was obtained. These results can be applied to determine the practical conditions (temperture, vacuum degree, type of distilla¬tion furnace, times of distillation and control of product composition) in distillation of a crude metal or an alloy.INTRODUCTIONRefining and separation of various impurities from nonferrous crude metals by vacuum distillation have many the advantages of high metal recovery, impurities recovered in metallic state, flowsheet simplified, good enviromental protection, low operation costs and in complex equipment. So in recent years this method has been adopted widely.Vacuum distillation has also been studied and used in separation of various elements from non-ferrous alloys and the area of its application is being extended rapidly.At this situation, some problems have been put up: What kind of impurities can be removed from crude metals? What kind of alloys can be separated by vacuum distillation? In present paper, attemps have been made to answer these problems and combine with practical results to analyse some valuable data obtained from testwork on vacuum distillation of crude tin and Pb-Sn alloy."

Jan 1, 1988

By Sergio N. Monteiro

Polymeric matrix composites reinforced with coir fibers are being used in many industrial applications such as automobile interior panels and cushions. These composites have relatively low mechanical strength due to the weak fiber/matrix interface. The objective of the present work was to investigate the effect of a surface alkali treatment of the curaua fiber on the mechanical behavior of polyester composites with different amounts of these fibers. The treatment, also known as mercerization, was performed with distinct concentrations, 0.1 and 10% of NaOH at 1 min and 1 hour, before incorporation of the coir fibers into the polyester composite. The results showed no significant change in comparison to similar untreated coir fiber composites. A microstructure analysis revealed that, in addition to reducing the hydrophilic characteristic of the fiber,the treatment also affects the surface morphology and impairs the fiber/matrix interfacial strength.

Jan 1, 2009

By Daojin Cao

Aiming at many controversial reports on Raman spectral pattern of octamolybdate ion in aqueous solution appearing in the literature, a new method for the establishment of corresponding relation between Raman spectral pattern and chemical components of aqueous molybdate solution was put forward using spectroscopy measure and component analyses of saturated solution of ammonium octamolybdate hydrate known structure. It was found that the main characteristic of Raman spectral pattern of the saturated solution was described as the same ?double-peaks, hereinto a weak peak at the boundary? as some literature, but chemical components of the saturated solution were affirmed to be octamolybdate ion (Mo8O264-) and double protonated heptamolybdate ion (H2Mo7O244-), which were in equilibrium in aqueous solution each other. The authors propose that the pattern of the saturated solution can be regarded as the standard pattern of primiparous octamolybdate ion during acidified molybdate solution. It is satisfying that the standard pattern is applied to the identification of primiparous octamolybdate ion during acidified molybdate solution.

Jan 1, 2006

By S. Castro, P. Alfaro, C. Moctezuma

IMMSA operates a conventional roasting-leaching-purification-electrolysis plant for the production of zinc from concentrates in San Luis Potosi, Mexico. The leaching circuit was designed to take into consideration a feed mixture to the roaster with a maximum iron content of 7%. Since the start-up of the plant in 1982, the zinc recovery increased to 94.5%. However, an increase in the iron content in 1997 caused an important decrease in the global zinc recovery. Two new steps were added to the leaching circuit and modifications were made to the other steps in order to increase zinc extraction. Two new automated press filters were installed to replace the original vacuum drum filters and to minimize soluble zinc losses. Additionally, the residue treatment steps in purification were modified and a calcium removal circuit is just starting operation. These actions, besides improving the operations, have as the main objective to increase the global zinc recovery to levels above 94.5%.

Jan 1, 2000

By Kimberly Conner-Mills

Due to increasingly stringent worldwide environmental regulations for gaseous, aqueous and solid waste emissions, conventional smelting technology cannot effectively process arsenic containing materials. Many globally significant copper properties have copper sulfide mineralogy that has a high arsenic content present as enargite with significant contained precious metals. As global copper, silver and gold demand increases while significant world resources decrease, treatment of sulfide orebodies with enargite is becoming increasingly important. Methods to selectively dissolve and fix arsenic, leaving behind clean copper and precious metals-bearing concentrates could effectively treat these ores.

By E. Gratz, U. Pal, A. Powell, S. Pati, J. Milshtein

"The solid oxide membrane (SOM) process has been used at 1150 'C to produce magnesium by direct electrolysis of its oxide. Magnesium oxide is dissolved in a molten CaF2-MgF2 ionic flux. An oxygen-ion-conducting yttria-stabilized zirconia (YSZ) SOM membrane separates the cathode and the flux from the anode. During electrolysis, magnesium ions are reduced at the cathode and Mg(g) bubbles out of the flux into a separate condenser. The flux has a small solubility for magnesium which imparts electronic conductivity to the flux. The electronic conductivity decreases current efficiency of the process and also degrades the YSZ membrane. This study investigates different methods for reducing the electronic conductivity of the flux due to magnesium solubility. One effective method shown here is inert gas flushing near the magnesium nucleation site. Potentiodynamic and potentiostatic experiments along with AC impedance spectroscopy are used to characterize the effectiveness of the approach.IntroductionMagnesium is the third most abundant metal in the earth's crust. Since magnesium is the lightest of all metals used for construction alloys, magnesium is the leading candidate to replace steel and aluminum in automobiles. Automobile manufacturers would like to increase magnesium content from 4-5kg per vehicle to 40-IOOkg per vehicle [I]. Using magnesium alloys instead of steel and aluminum can reduce automobile weight and improve fuel efficiency. However, in order for automobile manufactures to make this change, it is generally believed that new cost effective methods of magnesium production must emerge.One approach for magnesium production which has been shown to be effective on a laboratory scale is the direct electrolysis of magnesium oxide utilizing an oxygen-ion-conducting solid oxide membrane (SOM), this is known as the SOM process [2]. A recent study estimated that a commercial SOM plant could produce magnesium from magnesium oxide at a cost that is 40% less than current technologies [3]."

Jan 1, 2012

By Nobuyuki Higashiyama, Ikuo Yonezu

"Hydrogen-absorbing alloys containing rare-earth elements are used in high capacity nickel-metal hydride secondary batteries,' hydrogen storage systems for portable fuel cells, and refrigeration systems. New hydrogen-absorbing alloys containing rare-earth elements have also been developed and introduced into these applications. High performance in nickel-metal hydride secondary batteries is strongly demanded because of the remarkable advancements in portable electric appliances. A large hydrogen absorption capacity, high electrochemical reactivity and superior corrosion resistance in an alkaline solution are required for hydrogen-absorbing alloys used in nickel-metal hydride batteries. The aim of this investigation is to improve the performance of conventional LaNi5 type hydrogen-absorbing alloys. For example, Mm(Ni-Co-Al-Mn)„ type hydrogen-absorbing alloys with various non-stoichiometric compositions were developed. In addition, a new process of rapid quenching process was applied for preparing these hydrogen-absorbing alloys in order to improve their performance.IntroductionRecently, the trend in electronic appliances toward portability has increased the demand for high capacity of secondary batteries as power sources. Since nickel-metal hydride batteries were first commercialized in 1990 in Japan, they have become increasingly popular as power sources for cellular phones, portable computers, electric shavers, and other, products.The performance of a nickel-metal hydride battery, such as its discharge capacity, high rate capability, and charge-discharge cycle life, strongly depends on the characteristics of the hydrogen-absorbing alloy negative electrode. Many types of hydrogen-absorbing alloys have been developed so far. For a hydrogen absorbing alloy to be used as the negative electrode material, (1) it must allow a large amount of hydrogen to be absorbed and desorbed in an alkaline solution, (2) its reaction rate should be high, and. (3) it must have long term durability under repeated charge-discharge cycling. However, LaNi5, a typical rare earth-nickel type alloy, shows significant capacity deterioration during repeated charge-discharge cycling. Therefore the first step in its development was to obtain sufficient corrosion resistance of the LaNi5 alloy for its use as an electrode material. A partial replacement of nickel with cobalt and a substitution of the lanthanum- content with misch metal (Mm), a mixture of rare earth elements such as lanthanum, cerium, praseodymium and neodymium, were very useful in improving the charge-discharge cycle life. However, the discharge capacity of the alloy was still not sufficient for a practical battery. A study of the effect of the partial substitution of aluminum and manganese showed that the best alloy composition was Mm(Ni-Co-Al-Mn)x, as follows.The stoichiometry x of Mm(Ni-Co-Al-Mn)x largely affects the discharge capacity and cycle life. Theose alloys with non-stoichiometric alloys with the compositions of [Mm(Ni-Co-AMn)x: 4.7<x<4.8] have a large capacity and a long cycle life. Nogami' et al. reported that 'a non-stoichiometric alloy with a Mm(Ni-Co-Al-Mn)x (x=4.76) composition showed approximately 10% higher discharge capacity than the stoichiometric alloy (x=5) [1] and greater influence of x on the electrochemical properties of multi-component AB„ type hydrogen-absorbing alloys for batteries."

Jan 1, 2000

By Laurent Cohen

Since the 1970s, Solvent Extraction (SX) in hydrometallurgical processes has been a key enabling technology in the production of high-purity metals. Examples include copper, rare earth oxides, uranium, cobalt and nickel. Notwithstanding incremental improvements in extractant formulations, few breakthroughs can be recounted in this industry outside of the initial amine-, oxime- or phosphine-based reagent chemistries. However, the advent of lithium-ion batteries and their stringent requirements for critical materials (lithium, cobalt and nickel) offer new challenges and opportunities for SX. Solvay recently introduced a new extractant for lithium, CYANEX® 936, and developed unique modeling software capabilities in cobalt/nickel separation using CYANEX® 272, zinc SX using DEHPA® and rare earth separations using CYANEX® 572. This paper discusses trends in SX and provides insight on processing of critical materials essential to energy sources. It also summarizes the technical and economic benefits based on extractant selection and advances in modeling.

By Chen Dong, Yuanling Gao, Jilai Xue, Jun Zhu, Luxing Feng

"Porous Ni-Ti alloy has many applications in a wide range of engineering areas. The porous NiTi alloys were prepared from Ti and Ni powders in sintering process under argon atmosphere. The major chemical compositions of the sintered Ni-Ti body were Ni Ti, Nh Ti4O and Nh Ti, respectively, the internal pore structures were characterized by image analysis technique, which were dependent on various processing parameters such as sintering temperature, amount of poreforming agent, forming pressure, etc. The results show that the porous alloy samples had the characteristics of uniform pore and high open porosity; pore-forming agent and sintering temperature are important factors in porous; pressure affected the sintered products' pore, by affecting the combination of alloy powder with pore-forming agent.IntroductionPorous Ni-Ti alloy materials exhibit not only excellent shape-memory and superelasticity, high yield strength and ductility, good corrosion resistance and biocompatibility, but also have low density, low stiffness, and high energy absorption rate due to their porous structures [1]. In recent years, these porous Ni-Ti alloys have found applications in a wide range of engineering areas, such as bone implants [2-4], impedance-matching connectors [5], energy-absorbing structures [6,7], separators [8] and actuators [9], etc.Pore characteristics can play very important role in determining of the performance of porous NiTi alloys. For example, when the alloys are used to repair or replace hard tissue implant material, the pore shape and size not only determine their mechanical properties, but also have great effect on the fluid transmission of human body. The pore characteristics can also influence the stressstrain behavior of the porous Ni-Ti alloy and, thus, strongly affect their mechanical properties, superelasticity, and fracture mechanisms [10].In this study, the Ni-Ti alloys with high porosity were prepared in a powder sintering process under argon gas. The pore characteristics were investigated using SEM, XRD and image analysis techniques, especially in association with the content of pore-forming agent, sintering temperature and compacting pressure."

Jan 1, 2011

By Thomas Schuman, Jaan Kers, Lucas N. W. Damoah, Xiangjun Zuo, Lifeng Zhang

"Rapid technological innovation has propelled the use of electronic equipment leading to the generation of more and more waste electrical and electronic equipments (WEEE). Printed wiring board (PWB) is a component made of one or more layers of insulating material with electrical conductors. To investigate an environmentally friendly process to recycle PWBs, PWB samples with and without additives were pyrolyzed. Liquid, gas and solid products were achieved with different conversion fraction. Analysis of the exhaust gases from the experiments using GC-MS and MS showed that without CaCO3 additives poisonous gases such as C6H6 and HBr were produced which were adequately controlled if CaCO3 was added.IntroductionPyrolysis is one of the best methods for treating complex mixtures of waste polymers and to recover the material and energy content. The process consists of thermal decomposition at moderate temperatures in total absence or small amount of oxygen in which the structures of polymers break down into smaller intermediate products "". The decomposition temperature of a substance is the temperature at which the substance breaks up into smaller substances or into its constituent atoms 2). Thermal treatment of PWBs were reported using DC Arc Plasma furnace 3), and fixed bed reactor 4). One drawback in dealing with thermal treatment of PWB scraps is the likely production of super-toxic halogenated dibenzodioxins and dibenzofurans from the bromine containing structures. Pyrolysis of organic materials contained in waste PWBs leads to the formation of gases, oils, and chars which can be used as chemical feedstock or fuels ""'. Dehalogenation of the pyrolysis product of electronic scraps is essential to make it commercially acceptable. It would be obviously the most advantageous solution as pyrolysis and dehalogenation are carried out simultaneously. Reported pyrolysis investigations are at experimental stage and have been carried out in vacuum, molten salt, fluidized bed, rotary kiln, entrained, stationary, and moving bed reactors 7). Comparing to the incineration and combustion of PWBs, the pyrolysis process has several characteristics: 8'"">) 1). Converting the organic solid substance into fuel gas, fuel oil and carbon-black as storage energy; 2) Emitting toxic substances such as sulfur, bromine and heavy metals in wastes; and 3) Keeping metals from being oxidized. Although many researches into the pyrolysis of PWB wastes have been reported, most of the works have been carried out using analytical pyrolysis techniques or very small batch reactors ""~'5). Also, most of the works for the pyrolysis of PWBs haves concentrated on the composition of the organic products, particularly the brominated organics. The current study is to investigate the pyrolysis of PWB powders in a small TG-DTA scale and a 50-gram tube furnace scale."

Jan 1, 2011

By Leonard A. Duval

This concept employs a viable energy saving method that uses a solvent to separate oil from particle matter; it can be used in metal forming industries to deoil sludges, oxides, and particle matter that is presently committed to landfill. If oily particles are used in their oily state, severe consequences to environmental control systems such as explosions or filter blinding, occur in the air handling equipment. This is due to the presence of hydrocarbons in the stack gases resulting from the oily particles. After deoiling, the particles can be recycled and the separated oil can be used as a fuel. The process does not produce a waste of it&apos;s own and does not harm air or water. It demonstrates the dual benefits of being commercially viable and in the national interest of conserving resources.

Jan 1, 1994

By G. Gomathi, K. Asokan, K. Subramanian

An electrochemical reactor with anode and cathode chambers separated by a composite perfluoro polymer cation exchange membrane was designed, fabricated and used for the reduction of dissolved carbon dioxide under ambient conditions to formate. The flow reactor enhanced the mass transfer of carbon dioxide compared to the batch reactor. Experiments were conducted using two different perfluoro polymer membranes - Nafion 961. Efficacy of CO2 reduction on various cathode materials (Cd, Pb, Sn and Zn plated stainless steel woven mesh) were determined. Optimum values of flow rate and current density were evaluated for the energy efficient formation of formate in aqueous KHCO3 (pH 7.5-8.5) buffer solutions.

Jan 1, 2008

By Ali Unal, Ali I. Kahveci

Alcoa developed a fractional crystallization process some 30 years ago as a method to purify aluminum. Depending on the purity of feed metal, it has been commercially used to make 3N7-6N purity aluminum. As an extension of this technology, Alcoa has experimented with purifying various aluminum alloy scrap for the purpose of recycling. Purified aluminum alloy scrap can be reused for making the same alloy. This presentation will discuss Alcoa fractional crystallization technology and its application to alloy scrap processing. Process capabilities and the partitioning of eutectic and peritectic impurities during fractional crystallization will be discussed for the alloy systems investigated.

Jan 1, 2000

By Alexandra Anderson

A computational fluid dynamic (CFD) model has been developed using ANSYS Fluent 17.0 to help identify areas of high wear within the refractory lining of a secondary lead reverberatory furnace. Once a base case simulation was validated using data from an operational furnace, areas of potentially high refractory wear were determined through the calculation of the temperature and velocity distributions within the furnace and on the hot face of the refractory lining. The CFD model was used to assess whether the predicted areas of high refractory wear could be minimized through changes burden geometry. The results showed that shape of the burden geometry greatly affected the overall flow patterns and heat transfer within the furnace.

By J. K. Brimacombe, I. V. Samarasekera, B. G. Thomas

"Mathematical models have been developed for the processing of static cast steel ingots and are app1ied to investigate the mechanisms for the formation of panel cracks. Panel cracking is an intermittent but persistent defect that causes affected steel ingots to be scrapped. A two-dimensional, finite-element, heat-transfer model was formulated and employed to calculate the temperature distribution in both large and small steel ingots during the various processing stages from initial casting to the start of rolling, including solidification, cooling in the mold and in air, reheating in the soaking pit, and subsequent air cooling. The stress state in the ingot arising from the calculated temperature variations was then determined. This involved the development of a transient, elasto-visco-plastic, finite element, thermal stress model, including the effects of phase transformation volume changes and kinetics creep, and temperature-dependent, mechanical properties. The results of the mathematical model predictions of temperature and stress were then used to determine the mechanisms and to suggest solutions for two different types of panel crack formation. Mid-face panel cracks apparently form during air cooling when the mid-face surface temperature is between the Arl and 500~C. Off-corner panel cracks appear to initiate internally during the early stages of reheating but do not propagate to the surface until much later. IntroductionPanel crack formation in static-cast steel ingots is a defect that has been plaguing the steel industry for several decades. Although the problem is intermittent, it is also serious since affected ingots must be scrapped. Panel cracks are manifested as two distinct types of cracking problems. ""Mid-face"" panel cracks are found exclusively in small, 2 to 6 ton, medium carbon steel (0.3 to 0.7% C) ingots and usually exhibit a single, continuous, longitudinal crack down the center of one of the ingot faces as shown in Fig. l (l). ""Off-corner"" panel cracks often form roughly oval, discontinuous crack patterns on the wide faces of large, 20 to 30 ton ingots as seen in Fig. 2 (2). They affect only low carbon steels (0. l to 0.2% C) with high manganese content. Both defects affect only aluminum-treated steels and are caused by a combination of intermediate temperature ductility loss involving aluminum-nitride precipitation and thermal stress generation. The ductility problem has received a good deal of attention which was the subject of a recent review (3). The present study was undertaken to investigate the thermal stress aspects of the problem through the development of mathematical models of heat transfer and stress generation in static-cast steel ingots. The ultimate objective was to elucidate the mechanisms of formation for both types of panel crack and to evaluate possible solutions to the problem."

Jan 1, 1986

By Emilia Visileanu, Eftalea Carpus

"The strategy of developing the Romanian textile industry sub-sectors envisages the achieving of certain superior production indices, from a physical and value point of view, in 2010, a quantitative increase of textile wastes by 14% in 2010 as compared to 2000, implicitly. The percentage of the turned-to-profit wastes will have an increasing tendency, from 53.6% in 2000 to 74.7% in 2010. The article synthetically presents the innovative elements of the technology of processing the industry textile wastes.1. Introduction“People will need to re-adopt this sense of rarity that has been forgotten over the last two centuries. Humans need to collect, sort, recover, going back to the old ideal of alchemists: complete the material cycle, turn waste into resource, reduce all forms of predatory behaviour as much as possible”Irrespective of the historical period, geographical positioning, economic power or employed technologies, wastes resulted and will result in a bigger or smaller quantity as long as life and activity on Earth go on. The negative effects of these over the environment factors and implicitly over population health are well known all over the world and not approaching this matter enough may have catastrophic consequences over life. Having in view these aspects, finding solutions for diminishing the general waste quantity and limiting the negative effects of those products is important, by effecting the reusing of the recyclable ones in the production processes as secondary raw materials, and by ecologically treating and storing those than cannot be reused.2. Experiments and researchesThe textile industry affects the environment by the high water, energy and chemical consumption, as well as by the high quantity of wastes that are the result of using an impressive number of chemical substances and technological processes.The development strategy of the Romanian textile industry sub-sectors foresees, for 2010, the achieving of certain higher production indices as compared to 2000, both in terms of materials (as merchandise) and in terms of value, which implicitly leads to a quantitative increase of wastes.The flexible, economic and ecologic technologies which include systems of waste preliminary preparing (cutting, opening) and conventional or non-conventional system of processing the recovered fibres lay at the basis of substantiating the activity of implementing the notion of zero wastes."

Jan 1, 2008

By G. Richards

The Trail smelter of Teck Metals Ltd. produces about 90,000 tonnes of lead per year through two stages of refining following KIVCETTM smelting. Bullion from the KIVCET furnace is first treated in a pyro-refining plant in preparation for Betts electrorefining which makes 99.99% pure lead. Pyro-refining consists of number of integrated unit operations to remove primarily copper, arsenic, antimony and tin. The operation of this plant to meet the specifications for electrorefining requires attention to bullion management and selective use of reagents. The processes used for pyro-refining are reviewed in terms of chemistry and control.

By S. -H. Jeon, Y. -S. Choi

"The three dimensional current distribution on the rectangular cathode is predicted using a boundary element method with a linear element of trigonal type. The effect of cell geometry and anode shape on current distribution is simulated. Calculated results compare well with experimental results. The proper combination of anode size and distance between electrodes increase the current uniformity.The importance of electrodeposition as a fabrication technology in the electronics industry is large and growing. The main advantages of this wet processing method, in comparison to other dry processing methods, lie in its high yield, rapid processing and low cost. In nearly every application of electrodeposition the pursuit of deposit uniformity, especially thickness uniformity, has been technically imperative. The thickness uniformity of the deposit depends largely on the current distribution over the cathode. The current distribution is primarily determined by the geometrical characteristics of the electrodes and the cell. Also the polarization at the electrode surface and the mass transfer affect the current distribution.The current distribution is an important consideration for those involved in designing electrochemical systems and electroplating systems in particular. Although it is important, the common practice in industry is to use trial and error method to design the cell that optimize the uniformity of current distributions in electroplating. The purpose of this paper is to illustrate the useof boundary element method to predict three-dimensional current distribution in rectangular cell.The calculation of the current distribution is possible by various numerical techniques, which include the finite difference method (FDM)1, the finite element method (FEM)2, and the boundary element method (BEM)3,4. These methods of the numerical calculation have various problems, respectively, but the BEM is considered to be the most efficient. This is due to the fact that the BEM has the advantage of solving field equations only on the surface of a calculation domain. A good comparison between the BEM and the FEM for the secondary current distribution in a Hull cell was made by Matlosz et al.5The fundamentals on the theory of current distribution in electroplating are well-established in the literature by a number of authors.6, 7, 8 However, a small fraction of these works have been specially addressed to three-dimensional analysis, and, mostly thel·10 have focused on the problem qualitatively rather than quantitatively.Extending the previous work to three-dimension, we developed the program for the quantitative calculation of 3-dimensional current distribution using a boundary element method with a linear element of trigonal type. Integrals with singularity from the fundamental solution have been analytically computed and it is shown in detail in the Iiterature11. This paper deals with the three dimensional current distribution for the electrode position of copper in a cubic type cell and the effect of anode shape, size and the distance between electrodes on current distribution is studied."

Jan 1, 1997

By A. J. Paul

Traditionally, 16"/50 caliber projectile shells have been fabricated from forged steel. The Naval Surface Warfare Center (NAVSWC) has determined that cost savings of approximately 60% (-$4.7M/year) as well as improved shell fragmentation can be achieved by casting these shells from austempered ductile iron. One of the technical concerns arising out of this material substitution is the role of the casting process in controlling the quality of the cast shells. Optimizing the process through proper orientation of the mold, placement of chills, superheat, etc., can minimize shrinkage porosity and, consequently, flaw size. For this purpose, the mold filling and subsequent solidification of the projectiles was simulated using a 3-D, fully transient, coupled fluid flow and heat transfer model based on finite differences. Several casting orientations were investigated and the casting parameters were varied to optimize the process and minimize casting defects. A comprehensive software tool, which was developed using state-of- the-art visualization techniques, has been used to analyze the process of casting. Emphasis is placed on the use of this visualization tool as an aid to the foundry engineer for process optimization.

Jan 1, 1992