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In today's world of strong competition and environmental consciousness, finding alternative materials that can be extensively used has become vital. As we all know the aluminum industry in India procreate a large amount of solid waste, like as red mud. During Bayer's alumina refining technique, Red-mud is created. Dumping Red-mud contaminates the soil and water, as well as covering valuable property, because it contains some harmful substances. Red mud can be used in mortar and concrete technologies to partially substitute cement in construction activities by studying the cementation behavior of the material. Because Red-mud, a waste product from the alumina industry, is free, using it to partially substitute cement is cost-effective. Because wastes no longer have any industrial applications, they can be used as a raw material in civil engineering area in a novel way. An experiment was carried out to partially substitute cement in concrete with red mud for different percentages (0, 5, 10, 15, 20 and 25 percent) by taking into consideration the cementitious behavior of the red mud. The compression, tensile, & flexural behavior of cement mortar specimens are researched and given within the scope of the cement's mechanical strength. The current article summaries research on the use of red mud as a partial replacement for cement in mortar & concrete, as well as its impact on mechanical and durability aspects. [ABSTRACT FROM AUTHOR]

At the enterprises for the production of aluminum, equipped with electrolyzers with self-baking anodes, during technological operations for the maintenance of baths and adjusting the chemical composition of the electrolyte, alumina and fluoride salts spill out through the ventilation grilles to the "zero" marks of the potrooms. As a result, an alumina-containing estimate of a complex variable composition is formed, containing a significant amount of valuable components - Na3AlF6, Al2O3, AlF3. In the process of sweepings collecting the estimate particles of valuable alumina turn out to be mixed with various materials (pieces of asphalt and concrete, sand), which leads to contamination of raw materials with iron and silicon-containing compounds (SiO2, Fe2O3) and makes it impossible to return it to the electrolysis process. This article is devoted to the issue of creating a technological scheme for processing alumina-containing estimates to reduce the content of SiO2, Fe2O3 impurities. According to the results of studying the phase composition of the samples, it was found that the estimate mainly consists of cryolite, chiolite, corundum, quartz, feldspar, carbonaceous matter and the technogenic phase of the composition (NaF)-1,5CaF2-AlF3. Highest concentrations of Si (1,91 %) and Fe (0,62 %) were found in size class of -0,63+0,315 mm. On the basis of microscopic studies, the contrasting properties of the raw materials were established. The developed hardware and technological scheme of processing allows for the processing of alumina-containing estimate, which will provide a product yield in the amount of 90% with Fe2O3 content - up to 1% and SiO2 - 1.5%, which will improve the technical and economic performance of production. [ABSTRACT FROM AUTHOR]

This paper analyzes the rapid development of the Brazilian aluminum industry and the subsequent deindustrialization of its most technologically advanced and capital-intensive processing stage. The paper argues that the interaction of five phases of globalization over the last century and a half with the strategies of aluminum firms and state development strategies explains this dramatic rise and decline. [ABSTRACT FROM AUTHOR]

Current research activities at the Institute for Metal Forming Technology of the University of Stuttgart are focusing on the manufacturing of hybrid components using semi-solid forming strategies. One process investigated is the joining of different materials in the semi-solid state and is so called “thixojoining”. In this process, metallic inlays are inserted into the semi-solid forming die before the actual forming process and are then joined with a material which was heated up to its semi-solid state. Earlier investigations have shown that using this process a very well-shaped form closure can be produced. Furthermore, it was found that sometimes intermetallic phases are built between the different materials, which decisively influence the part properties of such hybrid components for its future application. Within the framework presented in this paper, inlays made of aluminum, brass and steel were joined with aluminum in the semi-solid state. The aim of the investigations was to create an intermetallic bond between the different materials. For this investigations the liquid phase fraction of the aluminum and the temperature of the inlay were varied in order to determine the influence on the formation of the intermetallic phase. Forming trials were performed using a semi-solid forming die with a disk shaped design. Furthermore, the intermetallic phase built was investigated using microsections. [ABSTRACT FROM AUTHOR]

High-pressure die casting (HPDC) is a popular manufacturing process for aluminum processing. The slow shot phase in HPDC is the first phase of this process. During this phase, the molten metal is pushed towards the cavity under moderate plunger movement. The so-called shot curve describes this plunger movement. A good design of the shot curve is important to produce high-quality cast parts. Three partially competing process goals characterize the slow shot phase: (1) reducing air entrapment, (2) avoiding temperature loss, and (3) minimizing oxide caused by the air-aluminum contact. Due to the rough process conditions with high pressure and temperature, it is hard to design the shot curve experimentally. There exist a few design rules that are based on theoretical considerations. Nevertheless, the quality of the shot curve design still depends on the experience of the machine operator. To improve the shot curve it seems to be natural to use numerical optimization. This work compares different optimization strategies for the slow shot phase optimization. The aim is to find the best optimization approach on a simple test problem. [ABSTRACT FROM AUTHOR]

Red mud is an industrial waste generated during aluminum production from bauxite whereas rice husk ash is an agricultural waste from burning of rice husk that could cause negative impact on the environment if not properly managed. This study demonstrates the utilization of red mud in combination with rice husk ash to form a geopolymer-based material which can be used as bricks or replacement for traditional cement materials. The focus of this study is on the leachability of heavy metals in the raw materials and the geopolymer as this would be significant in assessing the environmental impact of the product. Leachability of metals such as Cu, Zn, Cd, Pb, Fe, and Cr was evaluated based on European (EN 124572-2 EU CEN TC292/ CEN TC 308) standard with pH value 7. Results indicate that the leachability of these metals in the geopolymer matrix is lower than that of the raw materials. [ABSTRACT FROM AUTHOR]

In the aluminum industry providing good quality materials is of utmost importance. Recently, after surface roughness, surface color became a role-playing factor for the customer. Producers require measurable values for classifying the surface decolorization to settle an agreement between the factory and the customer during a complaint. In this study two sources of the surface decolorization are identified in the case of aluminum-magnesium alloy sheets. Based on the results an evaluation scheme is introduced, which analyses the color components of the reflected light from the aluminum-magnesium sheet surface. [ABSTRACT FROM AUTHOR]

High-pressure die casting is an important process in the field of aluminum processing. Especially during the slow shot phase, the process parameters immensely influence the cast part quality. At the current state of the art, the appropriate process parameters are identified based on running-in trials and significant experience. To translate this experience into a mathematical framework is the aim of this work. The idea is to shift the running-in trials to the computer--now in the form of a numerical optimization. In view of the optimization, this paper presents a selection of objective functions. These are assessed with the respect to (1) their suitability as an overall quality measure of the casting process and (2) the extent to which they reflect the goals of the casting process. [ABSTRACT FROM AUTHOR]

Needless to say that the combined lot sizing and cutting stock problem is very relevant in a wide range of manufacturing industries. This paper presents an algorithmic solution approach to overcome the difficulty in solving non-linear integer formulation of the problem. The algorithm is based on the traditional approach where the lot sizing is determined for each period, and then the best cutting patterns are generated. However the algorithm adopts a backward lot-sizing based on available capacity and purchase cost burden index. Using 85 instances, the performance of the algorithm is assessed in terms of trim loss and computation time for a range of different piece lengths; number of final products; and number of scheduling periods. Good results are produced when compared with the practiced performance. [ABSTRACT FROM AUTHOR]

The application of ultrasonic scattering methodologies to measure inclusions in metals in the liquid state could enable the development of techniques for understanding non-metallic particulate inclusion content or cleanliness at different process areas. The MV20/20 ultrasonic system developed for the aluminum industry has achieved some success. However, the operational temperatures evident in steel production suggest many practical issues in designing an ultrasonic measurement system due to the inability to propagate an ultrasonic pulse directly into liquid steel. This paper describes the latest developments of a novel disposable ultrasonic probe that overcomes pulse introduction difficulties as well as some of the associated issues evident in liquid steel application. A trial at the Corus pilot plant facility in the U.K shows that probe design can be used to detect backwall signals at a distance of 20 cm with a signal to noise ratio in the region of 10 dB. [ABSTRACT FROM AUTHOR]

A study of materials used in the molds production to aluminium rims manufacture in the MADEAL S.A. factory was carried out for apply a plasma assisted surface treatment consists in growing TiAlN hard coatings that it protects this molds in the productive process. This coating resists high oxidation temperatures, of the other of 800 °C, high hardness (2800 Vickers) and low friction coefficient. A plasma assisted repetitive pulsed arcs mono-evaporator system was used in the grow of the TiAlN coatings, the TiAlN target is a sinterized 50% Ti and 50% Al, in the substrate they were used two types of steel that compose the molds injection pieces for the rims production. These materials were subjected to linear and fluctuating thermal changes in the Bruker axs X-Ray diffractometer temperature chamber, what simulated the molds thermal variation in the rims production process and they were compared with TiAlN coatings subjected to same thermal changes. The Materials characterization, before and later of thermal process, was carried out using XRD, SPM and EDS techniques, to analyze the crystallographic, topographic and chemical surface structure behaviours. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

How well is the "Washington Consensus" surviving local politics in the long run? When it comes to structural reform, how predictable are the proponents and opponents of privatization? Using Venezuela as a case study, this paper examines the relationship between the trajectory of neoliberalism and local processes of implementation. More specifically, it explores one aspect affecting neoliberalism's trajectory, public opinion, as a causal variable to explain outcomes of one type of neoliberal structural reform, privatization. This paper analyzes this relationship in the specific context of efforts to privatize state-owned aluminum and steel assets in Ciudad Guayana, Venezuela. Despite strong unions in these industries and a locally economy entirely dependent on these state-owned industries, there was little opposition to privatization, only concern about its local effects. After reviewing the privatization process at a national level and recounting the tension between local aspirations for privatization and the global structures constraining them, I present results from long-term content analysis, in-depth interviews as well as original survey data to show that despite a willingness among the population to face the risks of privatization, local groups also worked to have their interests represented in sale contracts. Even though local preferences in the non-core region were successfully articulated as part of sales contracts, long-term global price declines along with a global oversupply of steel and aluminum as well as steel and aluminum companies ultimately constrained the extent to which these provisions protecting workers and the local economy were fulfilled. [ABSTRACT FROM AUTHOR]

This paper presents the results of multi-performance optimization model of the Bayer bauxite leaching process in aluminum production. Data was collected under the industrial conditions from alumina plant "Biroč" in Zvornik, Bosnia and Herzegovina. The leaching paramethers (temperature of leaching, leaching time and CaO supplement) were analzyed as influencing factors in multi-response optimization of process outputs (Al2O3 losses, Al2O3 overall losses, Na2O losses in autoclave sludge, as well as the utilization of Al2O3 from the leaching of the sludge). The Taguchi orthogonal array (L16'), the signal-tonoise ratio (S/N), and ANOVA are used in this study to optimize the considered process inputs in regard to four measured process outputs. Furthermore, all S/N values in optimization model were fuzzified to obtain single universal output measure, which was than tested by ANOVA to determine the optimal set of input factors that could lead to the better efficiency of disscused process. [ABSTRACT FROM AUTHOR]