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By Bruce R. Conard

Consideration of environmental and human health issues in metallurgy is growing rapidly. While not all metallurgists need to have detailed expertise in environmental and health questions, they should be aware of the challenges the metals industry faces, be able to interact with colleagues in other sciences and contribute to sound metal resource management. Hydrometallurgists occupy a unique position among metallurgists because of their knowledge of the behaviour of metals in aqueous systems, which are of fundamental importance in understanding environmental chemistry and human toxicology. As a result, hydrometallurgists should more frequently and passionately lend their expertise in assessing environmental and health risks of metals and in helping to develop effective global guidelines, regulations and process and product stewardship strategies, thereby enabling metals to continue their beneficial service to society.

Jan 1, 2003

By J. A. Jensen

In-situ composites were produced in both Ti matrix (Ti-20Y) and Mg matrix (Mg-20Ti, Mg- 20Nb, Mg-20Fe, and Mg-8Li) alloys. In Ti-20Y, a < 1010 > fiber texture formed in both the Ti and Y phases, and UTS increased from 240 MPa, (as-cast) to 950 MPa after deformation processing to a true strain of 7.3. Deformation processing produced smaller UTS increases in the Mg-matrix composites, but they showed exceptional resistance to weakening from exposure to elevated temperatures. The Mg-20Fe, Mg-20Nb. and Mg-20Ti composites tolerated 6-hour exposure to 400°C with no reduction in their 250 to 300 MPa room temperature UTS. All composites studied had excellent ductility and machinability.

Jan 1, 1995

By K. Rajani Kanth

Environmental problem is the major concern for any industry and there is a great need to that along green lines. Sangam Dairy being one of the most famous and wide spread Dairies in India, produces wide spectrum of milk products. The BOD levels of effluent water of this industry with MIF treatment were found to be around 100 ppm. Lot of research has been expended in the past to bring down the BOD levels to bare minimum. The main objective of the present study is to minimize the BOD level to the required level stipulated by environmental standards by employing various seeding materials. For this purpose microbes like Bacillus Subtiles, Pseudomonas, Aspergillas, Staphylococcus, and Pencilium have been employed and BOD levels were analyzed. Various Reagents, solutions with different dilution levels have been successfully prepared. Initial and final Dissolved Oxygen levels were determined before and after incubation. From the DO data, BOD was evaluated for all samples and comparison analysis of various seeding material was carried to suggest the efficient seeding material for the ETP plant. In the process, solutions of different dilutions have been prepared using difficult reagents. These samples are treated with above mentioned microbes and BOD levels are estimated. It has been observed that staphylococcus and Pseudomonas proved to be the best seeding materials. When there microbes have employed BOD levels fall to less than 10 and 20 ppm respectively

Jan 1, 2006

By Lauri E. K. Holappa

The aim of the metallurgical process development is, nowadays, to search for the shortest, most economical, more environmentally friendly and sustainable route to convert raw materials to finished products. Recent progress in steelmaking processes ? BOF and EAF - has also motivated to search for more advanced casting technologies to shorten process route. Continuous casting, which became industrially feasible in the 1960s, is now a mainstream technology with over 90% share of the world steel casting. After the 1980s, the increase in steel production and consumption, particularly from automobile, construction and home appliances industries, required steel manufacturers to accelerate production with more concise procedures, so that near-net-shape casting took the trend of development in order to bypass and simplify the downstream processes, e.g. cold/hot rolling mill or extrusion mill, to directly obtain finished products with required geometries. Progress in flat and long products changed the industrial operation pattern, strengthened steel production efficiency, and formed the operation concepts of the integrated steelworks and mini-mills, respectively. Thin slab casting and strip casting have represented the most important progress and promise, in the recent years, of such innovations furthermore strengthening the production efficiency and, concurrently, coinciding with the demands of environmental protection and sustainability. This paper reviews the most recent progresses in near-net-shape casting and prospects the impacts to steel industries as well as the development trends of steel production, in general.

Jan 1, 2006

By Ruben Alvarado

The need to increase business competitiveness while complying with environmental requirements represent the great challenge that the Caletones smelter has decided to face in a new development project with a compromising and willing alliance with its workers. To date, the project is at the feasibility stage, with start up scheduled for the middle of the year 2002. The processing capacity of the Teniente Converters will be increased to levels up to 2400 tpd of chalcopyrite-based concentrates containing 30% Cu, by means of more intensive use of oxygen and improved stabilization of the overall operation. Productivity increses in the converting of white metal and the pyrometallurgical treatment of slag are also planned. As a result of related strategies, the productivity of the supporting facilities, included the capacitiy of the sulfuric acid plants, will be increased. An intensive and well-designed labor-upgrading scheme will allow the transformation of every worker into an expert in his working areas, thus becoming an active driving force in technology development. Mechanization, appropiate infrastructure, and complete process control and instrumentation will give to the skilled and motivated personnel the necessary tools in order to attain the highest potential ever reached with the Teniente technology. The necessary investment for this project based on the adding facilities to the existing plant is only a third of that required to reach the same objective for a greenfield plant, thus yielding a very high return on investment.

Jan 1, 1999

By A. Kapilashrami

Slag foaming proves to be both blessing and curse for the process productivity, depending on where in the process it occurs. In pyrometallurgical processes, slag foaming is often a result of chemical reactions taking place in the slag. As the slag composition and reaction rates are changing, foaming occurs under dynamic conditions. In the present work, slag foaming was studied with XRF. The foam displayed a fluctuating behaviour, unaccountable by existing models. The concept of foaming index was found not to be satisfactory in describing the foam, resulting in the need for alternative theories. The rate of fluctuations was seen to be related to the difference between rate of gas generation and rate of gas escape from the system (Ug-Ue) as well as the bubble sizes. Thus, model development of dynamic foaming phenomenon has to take the effective chemical reaction rate as well as the bubble sizes into consideration. The first step in obtaining foam is to form bubbles. In the present work, gas bubbles were generated through chemical reaction at interface between two immiscible liquids and the bubble formation was studied optically. The gas bubble size was seen to be uninfluenced by the reaction rate. However, bubble formation was seen to take place in one of the phases and since the bubbles consequently traversed the interface under the influence of buoyancy, the viscosity of the first phase was found to influence the final bubble size where increased viscosity would yield a larger bubble size.

Jan 1, 2006

By Carlos Maurício Fontes Vieira, Sergio Neves Monteiro

"A ceramic body traditionally used to produce bricks and roofing tiles with kaolinitic clays was reformulated by the addition of sand and illitic clay. The objective was to obtain a ceramic product with better technological properties. Specimens were made by uniaxial press-molding at 20 MPa and then fired at 850, 900 and 950°C. The determined technological properties were: linear shrinkage, water absorption and flexural rupture strength. The results showed that both sand and illitic clay contribute to reduce the water absorption of the industrial clayey body. With respect to the flexural behavior, it was observed that the incorporation of sand decreased the mechanical strength. On the other hand, the illitic, incorporated in an amounts of 30 wt.% contributed to increase the mechanical strength of the clayey ceramic.IntroductionCeramic bodies industrially fabricated in the county of Campos, north of the State of Rio de Janeiro, in Brazil, are still empirically elaborated using a mixture of local clays. These clays are predominantly kaolinitic mineral in nature, associated with high plasticity and elevated weight loss during the firing stage. Due to the excessive plasticity of the ceramic bodies, dimensional defects, which occur after drying and firing are usually obtained. Moreover, the kaolinitic nature and the presence of aluminum hydroxide (gibbsite) confer a refractory behavior to the local clays, which impairs sintering during the firing operation. In the case of clay ceramic products for civil construction, this results in greater porosity associated with elevated values of water absorption and low mechanical strength [1,2]. To avoid these problems, it is necessary to reformulate the ceramic body composition. The addition of both non-plastic materials to reduce plasticity and fluxes to condition the refractoriness is a possible alternative.As an alternative to reduce the plasticity of clayey ceramics sand, which is predominantly constituted of silica, can be used. The incorporation of sand in amounts of up to 25 wt.% to a clayey ceramic body used for roofing tiles fabrication was studied by Vieira et al. [3]. In that work specimens were prepared by extrusion and fired at 850°C. The results indicated that in the pre-firing stages the sand improved the workability of the investigated clayey ceramic body and facilitates the drying stage. It was also observed that the incorporated sand significantly improved the physical and mechanical properties of the clayey ceramic after firing. On the other hand, the apport of flux oxides could be done by the use of illitic clays that have a higher amount of alkaline oxides in comparison with the kaolinitics clays."

Jan 1, 2013

By R. R. Beebe

"Laboratory and pilot-scale tests are almost invariably required before metallurgical development can proceed. Difficulties with sampling, as well as with classical chemical and physical scaleups, are normally anticipated and relatively well-understood, but more subjective factors also come into play, including misunderstandings of the operating scheme chosen, wrong ""lessons"" learned from similar operations, failures to handle data appropriately, and even arbitrary intervention by management. The paper examines some of these subjective factors and suggests ways to guard against them. Several anecdotal case studies are used as examples, including when and where to heap leach or to mill specific types of gold ore.When the Romans first exploited the gold-rich gossans at Rio Tinto, they were guided by analyses and tests that delineated the ore deposits, identified the richer portions, and measured the gold recoveries achieved. There is little evidence, however, to suggest that test data were used to develop improved methods of metallurgical extraction. Indeed, it is likely that ores too difficult to treat were simply passed by, at least until improvements in full-scale operations could deal with them. For example, it is not difficult to imagine that an early metallurgist might test a tin ore by placing some in a fire; a smallscale emulation of the method actually used in practice."

Jan 1, 1997

By Nils Eivind Kamfjord, Halvard Tveit, Ingeborg Solheim

"Because of its negative environmental effect the attention towards NO emissions increases. This again leads to new demands from the authorities for better surveillance and control of emissions. Earlier and recent industrial measurements towards FeSi- and Si-metal furnaces reveal quite high NO-emission. The NO is believed to be produced in the combustion zone above the furnace surface, mainly as thermal NO.In order to expand the knowledge on NO-formation in silicon metal production, a pilot scale experiment in a 440 kVA silicon furnace has been carried out. The experimental set-up was designed with a view to be able to copy and manipulate the formation mechanisms for NO by controlling the flow of false air into the off-gas system.The resulting NO-values corresponding to the different air inlet to the furnace top, show significantly differences between the different air inlet geometries.IntroductionNOx is the common notion for the two gases nitric oxide (NO) and nitrogen dioxide (NO2). Since combustion of fuels, such as gasoline, diesel, bio diesel, propane, coal, and ethanol, forms NOx the dominating contributors to NOx emissions are the on-/offshore transportation industry and power generation based on fossil fuels [1]."

Jan 1, 2012

By Tzu-Chien Lin, Jack Tsai, Ming-Yu Lin, Der-Ray Huang, Jiin-Sen Chen, Jing-Xuan Lin

"In this paper, some DVD-R discs have been selected for long time light exposure test and high temperature and humidity test. Generally, recordable media under long time light exposure maybe be defected seriously. If we use Jitter value 8% as a reference to determine the life time of DVD-R samples, some discs defect after 5 hours of light exposure while some discs can endure over 25 hours. Also if we use reflectivity 45% to determine the life time, some discs defect after 30 hours light exposure while some discs can endure over 40 hours. From our results, the good samples show good characteristics of PI error. The absorption spectrum of recordable media is a good reference to justify the quality of dye media. These results can be used to estimate the life time of recordable discs.IntroductionIn general, the life time of DVD-R with a layer of organic dye recording layer is required for preservation in decades. In addition to optical characteristics and thermal properties, we still need to consider the stability of the dye in recording media. The presentation of the color on organic dye is not only related to the material's property but also related to the light exposure. In this study, we focus on the absorption characteristics and reflectivity of organic dye in optical recording layer after light exposure. The optical properties of discs depend on the functional groups and molecular structure [1]. According to ""DVD Specifications for Recordable Disc (DVD- R)"", the reflectivity should higher than 40%. From measured reflectivity, we can confirm that the important issue is whether dye be affected by light exposure or not. Because each specific functional group absorbs the specific spectrum, we can check the characteristics of functional groups from their UV/Visible Spectra. We also use High-performance liquid chromatography (HPLC) to detect the different components of dye on the recording layer [2]. The jitter value test is to test the error cause by digital signal of recording media. If we use jitter value 8% as a reference to determine the life time of DVD-R samples, the purpose of this study is to investigate the jitter values of recording media after high light exposure and high temperature/humidity test. The results of these test will be helpful for the development of long-life optical storage media."

Jan 1, 2012

By Michael S. Moats, Alexander Derrick

"The Winand Diagram was developed and has been used for decades to illustrate the interaction between polarization, mass transport and inhibition on the resulting structure of a metal electrodeposit. Recently, Adcock et al. criticized the Winand Diagram and developed their own structural diagram based on nucleation and plating overpotentials. Their work was based on zinc electrodeposition using a galvanostatic staircase method. This work explores the nucleation and plating overpotentials for copper electrodeposition using conditions typical for primary electrowinning and the galvanostatic staircase experimental technique. Additionally, the effects of organic additives and plating substrate on these overpotentials are reported.IntroductionThe control of electrodeposited structures is critically important to modem electrometallurgy operations to insure proper quality and efficient energy use. Electrodeposition of base metals for primary recovery (e.g. electrowinning or electrorefining), while similar to plating for decorative or device manufacturing, differs in the need to produce deposits that cover large areas and grow to significant thickness. Thus, controlling nucleation and particularly growth of electrodeposits is critically important for base metal electrometallurgical operations.The control of nucleation and growth on an industrial scale is most influenced by five parameters - current density, temperature, metal concentration, electrolyte agitation and additives. The effects of these parameters on electrodeposition are interrelated. To describe their effects on the type ofelectrodeposits generated and provide practitioners with a useful tool, Winand developed what is known as the Winand Diagram [1-2]. An adapted version of the Winand Diagram is shown in Figure 1.Winand characterized electrodeposits using Fischer's classification [3] and plotted the various deposit types versus inhibition on a vertical axis and the ratio of current density to bulk metal concentration on the horizontal axis. Inhibition intensity is a complex parameter and is still not well understood even though Fischer introduced the term in 1960 [4]. Often, inhibition intensity is simplified to equal the concentration of organic additive at the deposit surface and is related to the inverse of the exchange current density of the metal being deposited. The ratio of current density to bulk metal concentration is used to represent the ratio of crystallization overvoltage to mass transport of the depositing ion. As such i/iL could also be along the horizontal axis, where iL is the limiting current density of the electrodeposition reaction."

Jan 1, 2012

By Maria Kuttig, Christian Ruback, Gerhard Tober, Petra Maier

"It has been demonstrated that there is a strong relationship between work hardening with various post heat treatment and cyclic deformation behavior of structural steel S275. This study contributes to a project developing a process for the complex forming of steel, which combines rolling and bending. Due to the complex geometry of the final work piece, the deformation degree varies greatly. The forming temperature, as well as post heat treatruent, influences recrystallization processes in dependence of the local deformation degree, resulting in inhomogeneous microstructure of the work piece, which affects the quasi-static and dynamic properties. Cyclic creep and hardening or softening has been monitored during constant amplitude loading at stresses near fatigue strength in normalized condition. Work hardening, stress relief or recrystallization influence the cyclic deformation behavior and produces cyclic creep effects. Cyclic softening or hardening and creep were observed to occur in parallel. To what extent these properties are noted depends on the deformation degree.IntroductionThis work is part of a research project developing a new process for the three dimensional forming of steel. For the final product the fatigue strength influenced by the forming parameters is very important. Due to its complex geometry, the formed final plate has different deformation degrees. This leads to different recrystallization behavior and heat treatruent will have different effects on the microstructure. The peak deformation degree cp of the plate will be around -0.5 what leads to the analysis using rolling from 22 mm to 13 mm of thickness. The quasi-static material properties are very important for calculating the preliminary design. However, work pieces which are cyclic loaded need fatigue tests to describe the in-service material behavior. [l] For the prediction and to guarantee the wanted life-time of the part cyclic deformation tests are important. [2, p.23-32] When it is assumed that the work piece will only loaded in cyclic tension, fatigue testing will be done from zero to a maximum force value. In preliminary tests this value is the tensile fatigue strength from a Smith diagram. During processing, here forming, work hardening takes place resulting in strengthening. Therefore, in further tests maximum load can be increased to monitor cyclic deformation mechanism in more detail. However, to study cyclic creep and hardening and softening data should be evaluate over sufficient life time and should not fracture too soon."

Jan 1, 2013

By D. G. C. Robertson

Counter-current staged reactors offer several advantages over batch reactors for mass transfer between two phases. Several metallurgical reactor designs have utilized the counter-current principle, e.g. the WORCA and QSL processes. But before the principle can be widely adopted, it will be necessary to overcome several significant problems. These include the need to minimize longitudinal mixing in a single reactor or to use several separate staged reactors and to carry out different reactions in sequence, e.g. phosphorus oxidation and sulfur reduction. Theoretical and experimental approaches to these problems will be discussed in the paper.

Jan 1, 1988

By Yoshiaki Suzuki

In 1996, Saganoseki smelter & refinery successfully shifted to a single flash smelting furnace operation and increased the copper production capacity to 450,000mtpy in 1998. As the next step, Saganoseki planned to further increase the productivity in the smelting process. Applying the latest technology and carrying out technological innovations the throughput of the flash smelting furnace has been increased to 195 tons per hour and the matte grade has been raised to 68%. In 2005, six PS converters have been successfully consolidated into four by maintaining the production capacity. This paper introduces recent operation conditions and results of implementation of technological improvements.

Jan 1, 2006

By M. D. Bishop

Loss of organic solvent extraction circuits occurs through several accepted methods. Losses are commonly attributed to entrainment of the plant organic and evaporative loss of diluent. Evaporative losses of diluent have been estimated using various models or by considering all losses over and above entrainment to be due to evaporation. Other possible loss mechanisms are discussed and data on losses during weather conditions are presented. Accurate estimation of evaporative loss is vitally important to the industry due to both cost factors and environmental concerns. Data for and description of the Diffusive Flux Model are presented as an improved-method of estimating evaporative losses:

Jan 1, 1999

By W. Dutton, D. Simms

"The clearing of tuyeres on copper and nickel converters or similar metallurgical, vessels has, for many years, been done using mainly a manually- operated ""puncher"". One such device is the ""Gaspe Puncher"" developed in 1962 at Noranda's Gaspe Smelter. In an attempt to remove the operator from the cab of the Puncher, and to relieve him of a tedious, uncomfortable job, Noranda's Horne Division, in cooperation with Heath & Sherwood (1964) Limited and the Noranda Research Centre, undertook to automate the Gaspe Puncher used on the Noranda Continuous Smelting Process Reactor.The automated puncher is controlled by a Texas Instruments Model 530C Programmable Controller (PLC). Position measurement and control is done using non-contact position measuring equipment from the Tele-Controls Division of Geodimeter Inc. The entire automation system was installed on an existing Gaspe Puncher with minimum disruption to the operation of the smelting process. The operator's panel allows the user to ""block out"" any individual tuyere, and to select any of a variety of operating modes.The development of the automated puncher is described, and the results of several months operation are given.IntroductionThe tuyeres of copper and nickel converters and similar metallurgical vessels become blocked with solidified material formed by the cooling action of the blowing air. This restricts the converting operation. Clearing these blocked tuyeres has for many years been done mainly using a manually-operated ""puncher"" which uses a hydraulic or pneumatically-operated piston to drive a steel bar into the tuyere. The Gaspe Puncher, developed at Noranda's Gaspe Smelter in 1962 is one such device. It is currently being built and sold by Heath & Sherwood (1964) Limited, under license to Noranda. There are over 200 units in operation world-wide.In an attempt to remove the Puncher operator from the cab of the Puncher, and to relieve him of a tedious, uncomfortable job, and to increase productivity, Noranda's Horne Division, in cooperation with Heath & Sherwood (1964) Limited and the Noranda Research Centre, undertook to automate the Gaspe Puncher used on the Noranda Continuous Smelting Process Reactor. This paper describes the development of the automated Gaspe Puncher, its installation at the Horne Smelter, and the results of its operation after several months."

Jan 1, 1989

By Nathanael Hudson, Ruel A. Overfelt, Sushil H. Bhavnani

"In the aerospace and automotive industries, complex shapes exist which require casting. The problem with these cast parts is the empiricism required to develop the casting process and the accompanying time and expense to develop that process.There has been an interest in using fluidized beds to allow molding sand to better encapsulate the complicated surface geometries of lost foam patterns. Fluidization coupled with a mixing jet helps to homogenize the sand through stirring and may improve the integrity of the casting.At issue is the hydrodynamics of the sand and air around the foam pattern. The commercial package PHOENlCSTM is used to simulate the flow around the pre-casting foam geometry. Employing a two fluid approach, each component is considered a fluid that interpenetrates the other phase. To this end, the kinetic theory of granular 'flow for the sand phase was incorporated into the re-compilable PHOENlCSTM code.The results of this study consist of time-averaged void fraction patterns, with voidage being defined as the fraction of air in the mixture, around the foam pattern submerged in a two-dimensional fluidized bed. The model was benchmarked against past fluidized bed experiments. In order to better understand the dependence of the void fraction pattern around the lost foam pattern, certain physical parameters are varied and the resultant void fraction maps are predicted with the model. Physical parameters such as the aspect ratio of length to width, the placement of the mixing jet, and different mixing jet velocities are varied to illustrate the dependence of the time-averaged void fraction on those variables.Results consistently indicate the presence of channeling around the lost foam pattern, with the extent of the channeling and void formation reliant to a greater degree upon the placement of the mixing jet, and to a lesser degree on mixing jet velocity and aspect ratio.The increase in radial position of the mixing jet from the bed centerline had the desirable effect of granting the churning benefits of a penetrating jet, while at the same time minimizing the formation of excess void fraction at the top of the pattern."

Jan 1, 2001

By S. Kang, D. G. C. Robertson

Slag cleaning furnaces require extensive wall cooling because they involve the use of a superheated slag bath. This is in direct contrast to smelting furnaces, where the wall is usually (but not always) protected by "banks" of solid charge. In order to understand the heat transfer and flow in slag cleaning furnaces a number of model studies have been carried out using molten wax to simulate the slag. Wax is a good model fluid because, like slag, it has a high Prandtl number. Wax models cannot simulate the behavior close to the electrodes (DC arc or AC submerged), but they can and do give a good simulation of the flow and heat transfer at the wall. An understanding of these phenomena is of great importance for the design of cooling panels in the walls of the furnace. Since superheated molten slag will eventually wear away any refractory bricks over time, the wall cooling must be designed to form a frozen layer of slag, referred to as a "freeze lining". The heat flux density (Q/A) required to do this is given by Q/A = h* ?T, where h is the heat transfer coefficient in the slag phase at the wall, and Li T is the superheat (bulk slag temperature - liquidus temperature). Both Q/A and h vary greatly with position and both are usually a maximum at the slag line. In the experimental work, molten wax baths were heated by block heaters to provide similar energy densities to those encountered in commercial slag cleaning furnaces. This procedure was considered to be valid since most of the electrical energy into a furnace bath is dissipated as heat. Gas stirring was used to simulate the gas evolved at the electrode in real furnaces - the quantity of this gas could be estimated from a knowledge of electrode consumption. The similarity criterion was equal gas flow per unit area of surface, in model and prototype. Heat transfer coefficients were measured in the models as a function of power density, gas stirring, superheat, etc., and could be related to the full-scale operations by the use of dimensional analysis.

Jan 1, 1999

By Thomas Niehoff, Dave Stoffel

"Energy in the form of natural gas, oil and electricity is expensive and will continue to be a rare resource in the future. Recycling of metals, instead of primary production, is a logical and crucial step towards energy conservation. Energy consumption can be impacted by using advanced combustion systems for metals recycling. Air-fuel combustion has been the conventional method to melt and recycle metals. Global competitive pressures, “greenhouse” gas emissions, and high energy prices force melt shop operations to optimize energy usage and reduce overall operating costs. Oxy-fuel combustion and process technology can be applied to metal recycling operations to meet these objectives. Linde has converted several hundred furnaces from air-fuel to oxy-fuel technology and has extensive experience in optimizing the use of oxygen in furnaces. Additionally, Linde has the process knowledge necessary to avoid costly start-up issues that can accompany the transition to oxy-fuel technology. This paper will describe the benefits and potential issues for conversion to oxy-fuel.IntroductionThe furnace combustion system is the heart of a fossil fuel fired melting process and must be properly matched to the furnace to work as one cohesive unit. Furnaces vary widely in size, shape and features. Rotary furnaces are barrel-shaped and can be designed for tilting or nontilting operation. In a rotary furnace, the products of combustion create a single or double pass through the furnace prior to exiting. Reverberatory furnaces are box-shaped and can also be designed for tilting or non-tilting operation. Reverberatory furnaces are constructed of single or multiple chambers, with or without metal bath movement, and designed for continuous or batch processing. Different furnaces are used for different feedstock materials and products.Furnace combustion systems also vary in many ways. Combustion systems can be of air-fuel or oxy-fuel based technologies, or a combination of the two, resulting in an air-oxy-fuel system. Each of these types of systems has different combustion characteristics which can produce very different results. Here we will describe specific differences in melting processes and their associated energy requirements."

Jan 1, 2009

By N. J. Rarmrez, C. Perez, J. D. Calderon, L. Lopez

"Among the thermal characterization of any material, one of the variables to know is the coefficient of thermal conductivity because this value can tell how much heat passes through the material and if the material could be used as an isolator. In order to determine this parameter is required some kind of special equipment and controlled conditions which implies high costs in the development of tests. The present paper proposes a design of a low cost measurement system in order to determine this coefficient with the lower possible error. This equipment was thought for companies or labs where they do not have the economic resources or the infrastructure (environmental controlled labs, heat flux transducers, human resources with specialized knowledge) to do this kind of tests.The system is based on ASTM C 518 - 04 [l] and integrated by two plates (one that contains a thermal resistance and which temperature is controlled by a closed loop controller and the other one with a route of water flow). The thermal resistance is actuated by a relay and a supervisor system checks the total time the relay is on in order to determine the effective power applied to the system. The contact faces of the plates contain a group of temperature sensors connected to a data acquisition system that process and record the temperature in each measurement point.With the power applied to the system, the measurement of temperatures and a process of calibration is possible to determine the coefficient of thermal conductivity. IntroductionWithin the thermal characterization of a material of known variables is the coefficient of heat transfer, since this value can know the amount of heat the material is capable of transferring or isolating. To determine this ratio requires specialized equipment and controlled conditions, which implies high costs in the development of a test. This article proposes a design of a low cost machine to allow closer this coefficient with the least possible error. This equipment was done thinking about companies that do not have the infrastructure (laboratories, controlled environment, heat flux sensors, human resources expertise) and financial resources to conduct these tests."

Jan 1, 2011