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By F. Mucciardi

While flash smelting and converting are capturing a greater share of the market, injection through circular injectors will remain with us for the foreseeable future. The use of top lances for injection is a key feature in several processes (e.g. Mitsubishi, Ausmelt). Tuyeres, on the other hand, are incorporated into a number of processes (e.g. Noranda, Peirce-Smith). To date no lances or tuyeres are cooled by an external source. The reagent provides the bulk of the cooling. With limited cooling, it is normal to have substantial wear on the nozzles - especially in the case of lances. To overcome the issue of wear, a new patented injector (lance or tuyere) has been developed by Noranda and McGill University. This novel unit is based on heat pipe technology. It can operate for an extended period of time without wearing. Enhanced lance/tuyere life is achieved by operating the injector at a low enough temperature that promotes the formation of a thin frozen layer on the outer body of the unit. The vaporizing and condensing substance within the unit acts to cool' the high heat flux portions and dissipate the heat to areas of low heat flux outside the vessel. A fairly large number of tests have been conducted with a prototype unit. The tests have shown that the heat pipe lance is a viable unit. In this paper is detailed a test which illustrates how the lance functions when pure oxygen is injected into copper matte. In addition, the findings from a basic study of a heat pipe in high heat flux environments are also presented.

Jan 1, 1999

By M. E. Coleman, G. Money

"Clyde Materials Handling is an established customer-driven solutions provider, which utilizes its knowledge, expertise and technologies to transform the production processes of its customers, who operate in the ferrous and non-ferrous metals industries.With over 30 years experience in the process improvement industry, Clyde Materials Handling has helped their global customer base transform the way in which they operate their processes, which has enabled them to generate sustainable economic benefit and maintain their positions as leaders in their respective markets.Clyde Materials Handling has supported operators within the metals market by developing and deploying pneumatic conveying and pneumatic injection technologies. These environmentally supportive and sustainable solutions have been used to transport raw materials within operating facilities, from storage to silo, as well as injecting these materials directly into the heart of production processes.Clyde Materials Handling has worked closely with their customers, such as Codelco in Chile, where their pneumatic solutions have been used to inject a consistent, pulseless and accurate flow of copper concentrate into a bath smelter, which has helped to fuel the operational capacity, availability and productivity.This paper will discuss and highlight the ways in which pneumatic injection technologies, created by Clyde Materials Handling, and applied in partnership with their customers, have helped to improve the operational performance of the production processes of operators across the non-ferrous metals markets with specific reference to applications in the Peirce Smith Converter.Clyde Materials Handling has applications injecting Electronic Scraps, Dusts, Reverts, and other additives to the Peirce Smith Converter. They also have experience of modified PS Units used for Slag Cleaning. There experience with the Codelco Teniente Converter is also directly related to this area of operation."

Jan 1, 2009

By A. J. Williams, T. N. Croft, M. Cross

"The computational modelling of extrusion and forging processes is now well established. In this work a novel approach is described which utilises finite volume methods on unstructured meshes. This technique can be used to solve simultaneously for fluid flow, heat transfer and non-linear solid mechanics and their interactions. The approach involves the solution of free surface non-Newtonian fluid flow equations in an Eulerian context to track the behaviour of the workpiece and its extrusion/forging, and the solution of the solid mechanics equations in the Lagrangian context to predict the deformation/stress behaviour of the die. Some preliminary examples of this approach will be discussed.IntroductionThe computational modelling of extrusion and forging processes is now well established. Within the last 20 years the finite element method has become the most commonly used technique to simulate metal forming processes [1]-[4]. The Lagrangian and Eulerian type of formulation have been the two major approaches to this problem.Lagrangian methods are efficient and suitable for handling non-linear problems in which small strains prevail, boundary conditions do not change with the course of deformation, and where mesh distortion is not a critical factor in the analysis. Unfortunately, the above points are essential to any accurate metal forming analysis. The problems of mesh distortion and element entanglement pose a serious drawback on the use of such methods. Some automatic remeshing techniques have been developed for Lagrangian finite element analyses of metal forming problems [5]-[7]. However, these methods are not robust and efficient enough to remedy the mesh distortion problems in general. An alternative is to update the mesh manually but this is not always possible, and even when it is feasible it involves major interaction by the user. In addition, remeshing is usually applied to the whole domain which is not necessary and increases CPU time. The complexities associated with remeshing also affect the ability to parallelise the code."

Jan 1, 2001

By Yong-Moo Cheong

When the zirconium pressure tube(PT) is in contact with the calandria tube(CT) in the pressurized heavy water reactor(PHWR), the temperature gradient between the inner and outer wall of the PT results in a thermal diffusion of hydrogen(deuterium) and hydride blisters are formed on the outer surface of the PT. Since Zr-2.5Nb pressure tubes have a high risk for the formation of blisters during their operation in a PHWR, there is a strong incentive to develop a method for the non-destructive detection of the blisters grown on the tube surfaces. However, because there is little mismatch in an acoustic impedance between the hydride blisters and zirconium matrix, it is not easy to distinguish the boundary between the blister and the zirconium matrix with the conventional ultrasonic methods. This study has focused on the development of an ultrasonic method to detect the hydride blisters formed on Zr-2.5Nb pressure tubes. Hydride blisters were grown on the outer surface of a Zr-2.5Nb pressure tube using a cold finger attached to steady state thermal diffusion equipment. Ultrasonic velocity ratio method as well as conventional ultrasonic parameters with an immersion technique was developed to detect small hydride blisters on the Zr-2.5Nb pressure tubes.

Jan 1, 2006

By Donald P. Ziegler, James F. Klausner, Srinivas S. Garimella

"By 2015, nearly half the world's population will live in ""water stressed"" areas. Production of fresh water utilizing waste heat from industrial processes has been identified globally as a research priority.About 15% of the electricity required to produce aluminum is lost as waste heat in the off-gas. However, the low temperature (low grade) of the heat limits reuse. The off-gases contain 50-150 ppm SO2 ; tightening regulations coupled with increasing coke sulfur levels are motivating SO2 control, for which seawater scrubbing is attractive for smelters with suitable access.We describe a process that produces fresh water, utilizing the waste heat while scrubbing SO2 . It uses direct contact between seawater and off-gas to humidify the off-gas. The vapor is subsequently condensed. In smelter trials, a unit treating a slip stream produced high quality water in the anticipated quantity, attaining over 95% SO2 scrubbing. Future work involves scaling the process to be economically attractive.BackgroundPopulation growth, coupled with industrialization and urbanization, are increasing demand for water. Water scarcity already affects every continent. Around 1.2 billion people, or almost one-fifth of the world's population, live in areas of water scarcity, and 500 million people are approaching this situation. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions (< 1,700 m3 per person annually) [1]. An assessment by the U.S. General Accounting Office revealed that under normal conditions, by 2013, water managers in 36 states in the USA anticipate water shortages, and that the number might grow to 46 states under drought conditions [2].The obvious choice to alleviate water scarcity is the 97% of available water in the oceans, which is saline and requires desalination for use in biological, agricultural and industrial applications. Technologies developed for desalination include Thermal Distillation, Reverse Osmosis (RO), Electro-Dialysis, and Vacuum Freezing. Distillation and RO are the most commercially prominent. Thermal distillation technologies include Multiple Effect Distillation (MED) and Multi-Stage Flashing (MSF). The report commissioned by the World Bank [3] is one of the many excellent references on desalination technologies. According to the International Desalination Association working paper [4], there were more than 17,348 industrial scale desalination plants installed or contracted by 2004. The total production from these plants is on the order of 8.3 billion imperial gallons per day. RO provides 47.2% of the total capacity. The leading thermal process, MSF, provides 36.5% of the total capacity. Although MSF and RO technologies currently provide the most cost effective means for desalination, their drawback is that they are very energy intensive, and whether or not they remain cost effective strongly depends on energy prices and energy supply."

Jan 1, 2012

By Paul C. Turner

In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium, and titanium cost has prevented its use in non-aerospace applications including the automotive and heavy vehicle industries.

Jan 1, 2001

By S. Viswanathan, A. S. Sabau

"Dimensional changes between a pattern die and its corresponding investment casting part occur as a result of complex phenomena such as thermal expansion/contraction and hot deformation (elastic, plastic, and creep) during the processing of the pattern material (wax), mold material (shell) and solidifying alloy. Determining the pattern tooling dimensions is crucial to the dimensional control of the investment casting process. To date, computational methodologies have not been applied to the prediction of dimensional changes in investment castings.This paper deals with the evaluation of wax pattern dimensions, which is one important factor in determining pattern tooling dimensions in investment casting. Cerita 29-51, an industrial wax, is considered in this study. The wax pattern dimensions are determined by considering its thermo physical and thermomechanical properties, restraint of geometrical features by the metal die, and process parameters such as dwell time, platen temperature, injection pressure, and injection temperature.IntroductionThe investment casting process involves making a disposable wax pattern by injecting wax into a metal mold, building a ceramic shell mold around the wax pattern by the application of a series of ceramic coatings to the wax pattern, dewaxing the ceramic shell mold, and casting the alloy into the shell mold. Dimensional changes between the pattern tooling and its corresponding cast part occur as a result of thermal expansion, shrinkage, hot deformation, and creep of the pattern .material (wax), mold material (shell), and solidifying alloy during the processing [1]."

Jan 1, 2001

By Vijaya Thangavelu

Biological leaching of low-grade nickel laterite is based on a non-traditional leaching of oxide minerals using heterotrophic micro-organisms. The organisms solubilise metals by excreting organic acids; these acids then form complexes with heavy metals. High salinity of water supplies and soils in the vicinity of nickel laterite ore bodies is a major abiotic stress to fungi and represents a major challenge in the application of bioleaching process in-situ. Salinity exposes fungi cells to Na+ toxicity and osmotic stress. This study examined the salt tolerance development of Aspergillus foetidus based on gradual acclimatization of organism, its salt threshold and the salinity effect on its metabolism. The biological leaching of weathered saprolite ore with the resulting halotolerant organism under saline conditions was assessed. It was observed that salinity stress affected the organism?s growth and energy utilization

Jan 1, 2006

By Y. F. Liang

Fe-6.5wt.%Si alloy has excellent soft magnetic properties compared with conventional silicon steel. It is very brittle at room temperature due to appearance of ordered phases, like B2 and DO3. In this paper, we investigate the effect of ordering on cold workability of this alloy. Methods of rapid quenching and hot rolling were utilized. It is found that rapid quenching and proper heat treatment of the hot rolled sheet could decrease the degree of order due to the very high solidification rate and high cooling rate. The rapid quenched sheet and hot rolled sheet after proper heat treatment could be cold rolled without crack. Microstructure, phase ordering, micro hardness, and cold rolling properties were investigated by Optical Microscope, X-ray Diffraction, Micro Hardness Indenter and Four-high Mill.

Jan 1, 2009

By Jacques J. Eksteen

Any effort to improve the metallurgical control of industrial furnaces employed in the primary extraction of high carbon ferroalloys are bound to fail unless the variability of the melt is not fully accounted for. A number of sampling campaigns were performed on both 3phase AC submerged arc and single phase DC open arc furnaces at different smelter sites in South Africa where High Carbon Ferrochrome is produced. It was found that the heterogeneity between multiple samples during a single taps were much higher that for heterogeneity found within a sample. Moreover, this heterogeneity (as quantified by the relative standard deviation per tap) varied with the operating conditions of the furnace, the element monitored and the type of furnace. A relationship was found between the relative standard deviation of certain elements and the degree of subcooling of the melt.

Jan 1, 2006

By Jinwu Kang

The hydraulic turbine blade of the matensitic stainless steel (Cr13%,Ni5%,Mo1%) is a kind of large and curved shape, which is susceptible to deformation in both casting and heat treatment processes. The coupling analysis of heat transfer, phase transformation and stress in heat treatment process of the turbine blade for Three Gorges Project is carried out by using Deform-3D software. Its temperature fields, phase fields and stress fields in heat treatment process are obtained. And its deformation is predicted. In the cooling process of normalizing, the blade exhibits relatively large deformation. Based on the stress analysis and deformation prediction in heat treatment process, an algorithm for the determination of reverse deformation of the blade casting in heat treatment process is presented. And the reverse deformation distribution of blade is obtained.

Jan 1, 2010

By Ahmadzadegan. Arash, Anil Saigal, Michael A. Zimmerman

"In this study, the rheology of liquid crystalline polymer (LCP) melts through simplified 2-D and 3-D die geometries is simulated using Polyflow™. It is known that rheological properties of LCPs are close to long chain polymers and their directionality is close to those of small molecule liquid crystals (SMLCs). As a result, different rheological models (both viscoelastic and generalized Newtonian) for long chain polymers in Polyflow™ were investigated based on the available capillary rheometer data. By varying the parameters in these models, it is possible to adjust the effect of shear viscosity, normal stress differences and relaxations times on the rheology of the polymer. The free surface of the extrudate coming out of the die is simulated and the amount of die swell for different types of rheological models is compared. This study indicates that the Bird-Carreau model best applies to thermotropic LCP materials as quantified by die swell. Since the rheology of the LCPs affects the orientation of the crystals, the result of this simulation can be further used to predict the orientation of crystallines inside and outside the die.IntroductionAny rod like molecule or crystal tends to orient itself in the direction of shear as it moves within a flow. Since polymers consist of long chains of molecules, they experience the same phenomena when flowing in the melt condition. For most polymers, the molecules change direction and distribute uniformly in space during the solidification. However due to the higher inertia of the crystals in the liquid crystalline polymers, the oriented crystals will keep their order during the solidification and as a result the final product will show anisotropy in material properties."

Jan 1, 2012

By A. S. Usmani

The flow associated with the pouring of molten metal into moulds has been modelled on the basis of certain simplifying assumptions. A finite element based Navier-Stokes equation solver has been used to analyse the flow. The velocities obtained from the Navier-Stokes equation solver are used to advect a pseudo-concentration function for modelling the fluid front. A simple problem with a known analytical solution is solved first to test the model. Subsequently, several more examples with varied geometrical configurations are modelled, including one with curved flow boundaries.

Jan 1, 1992

By Tian Sugui

By means of the measurement of the enduring property and microstructure observation, an investigation has been made into the influences of the element Re and TCP phase on the enduring property of the single crystal nickel base superalloys. Results show that the needle-like TCP phase is precipitated along the <110> orientation on {111} planes in Re-containing/free superalloys during the long term aging, the TCP phase is identified as µ phase, and the precipitated µ phase in 4.5%Re alloy is gradually spheroidized during aging. Thereinto, the needle-like µ phase may obviously decrease the enduring lifetimes of the alloys due to the consumption of the refractory elements and the effect of the stress concentration. But the stress concentration is not easily generated in the regions near the spherical-like µ phase, which is a main reason of reducing the enduring lifetime of 4.5%Re alloy to a small extent.

Jan 1, 2010

By Olga Frank-Kamenetskaya

The experimental results of study of atmospheric corrosion processes on Saint-Petersburg bronze monuments surface, received in situ and by means of simulating experiments, have been discussed. Influence of the time factor on corrosion film (patina) mineral composition has been analyzed. Direct dependence between patina mineral composition and environmental conditions has been proved. The sequence of patina phases crystallization has been established. Effect of the chemical composition and heterogeneity of artistic bronze and also monument surface structure on the rate of corrosion process has been regarded. The time variations of mass of the crystallized in the hydrochloric acid vapor phases have been investigated. The kinetic laws of their development at the initial stage of formation, indicating simple (non chain) reactions, have been revealed.

Jan 1, 2006

By Oliver Zach

To know as much as possible about the condition of the refractory material (lining thickness, slag layer, build ups, ...) in an high temperature furnace is very important due to the safety and economic impacts. The new CONSCAN system offers the possibility to measure the inner surface of an furnace, and based on this results to calculate the thickness of the refractory lining, slag layer, build ups,.... The CONSCAN System provides this results as figures and graphics. This system is also working under hot conditions so it is not necessary to cool down the furnace. Based on these results the process control and the refractory lining concept could be optimized for maximum campaign life of the furnace.

Jan 1, 2006

By Gary R. Adams

Coating thickness control is typically difficult with touch-up solders for galvanized steel, and corrosion properties and abrasion resistance are sometimes poor. This paper reports on progress in ILZRO-sponsored research to develop an improved touch-up solder. Encouraging results were achieved in torch soldering trials with zinc-tin based alloys. Mouldability and coating thickness control were achieved over a practical working temperature range in which the solders consisted of a viscous mixture of solid primary zinc phase particles in a liquid zinc-tin eutectic matrix The mouldability was dependent on the microstructure of the starting material, and optimum structures could be obtained through control of casting solidification rates and/or by the addition of small amounts of copper. Hardness and preliminary corrosion test results showed potentially good mechanical and corrosion behaviour. The absence of toxic materials ensures environmental friendliness. Comprehensive performance testing is continuing on selected experimental zinc-tin-copper touch-up solders.

Jan 1, 1992

The effect of rare earth element Y (0-2.0at.%) on the microstructure of TiAl alloys at the as cast and rapidly solidified conditions has been investigated. The results show that the addition of Y greatly refined the microstructure of TiAl alloys at both conditions. The refinement is more significantly with higher Y content. The refinement of Y in the cast alloys is attributed to that the strip-shaped Y-rich phase locating on the grain boundaries impedes the grain growth during solidification. In the rapidly solidified alloys, Y-rich phase dispersing uniformly as spherical particles in the matrix acts as heterogeneous nucleation sites which increases the nucleation rate of ??phase during the ????phase transformation, and produces a refined initial microstructure during solidification. Higher cooling rate restricts the grain growth during subsequent cooling.

Jan 1, 2010

By S. Illendula, B. Q. Li, R. A. Mirshams

"An integrated mathematical model is developed to represent the thermomechanical behavior of the materials and microstructure evolution during metal forging. The model development is based on the finite element solution of the thermoviscoplastic deformation of metals coupled with the internal state variable model describing the microstructure evolution involving work hardening, recovery, recrystallization and grain size distribution. The procedures for the integration of the microstructure model into the macro finite element model are described. Computed results for both macro and micro phenomena during metal forging, such thermomechanical deformation such as velocity field and effective strain rate and materials characteristics such as distribution of grain size and recrystallization volume fraction, are presented.1. IntroductionThermomechanical behavior and material microstructural evolution are two critical, interrelated aspects associated with metal workpiece undergoing large plastic deformations such as encountered in forging processes. In much of the modeling work up to date, these two aspects have been addressed separately. Die designs and forging processes are investigated using finite element based thermomechanical models while material dynamics during forging is studied, more often than not, as a separate subject. For many industrial applications, especially those involving novel, light and high strength materials, it is critical to combine these two aspects into a single, integrated model so that materials dynamics and thermomechanical deformation during forging processes can be considered simultaneously [1], thereby providing required information for intelligent process design and optimal process control."

Jan 1, 1998

By Zhang Chuanfu

Keywords: modified coprecipitation method, Ni-Co alloy powders, solid-solution oxalate, growth mechanism Homogeneous solid-solution oxalates of Ni2+ and Co2+ ions were synthesized by modified coprecipitation method and the composition and morphology of the fibrous solid-solution oxalates precursor were characterized by XRD, IR, DTA/TG and SEM analysis. The effects of feeding methods, pH values, precipitation temperature, reactant concentration, addition surfactant, alcohol washing and drying process on the morphology and dispersion of the precursor were investigated in detail. The experimental results showed that the coprecipitated powders have characteristics that are different from those of the mechanical mixtures with the same stoichiometry. Based on the observations of precursors growth and SEM morphology of the precursor, the oriented attachment was proposed for the well-aligned growth of the fibrous Ni-Co alloy precursor particles.

Jan 1, 2005