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Aluminum and its alloys are important and essential materials in contemporary life, due they have been serving to produce since structural aerospace and automobiles to construction materials and cans, thanks to the high specific strength, corrosion resistance, light weight and recyclability. This last characteristic has started to grow in interest, due to the need for alternatives to environmental conservation integrated to the productivity growth. In Mexico, alkaline batteries are the highest consumption and each one of the spend batteries get 30% of high purity ZnO, additionally; One of the materials with higher levels of recycling is aluminum cans (Al-Mg-Mn), which 240 tons are discarded daily. These two materials can be processed through the metallothermic reduction of oxides, which refer to the extraction of metals reducing their metal oxides by aluminum. Therefore, the production of Al-Zn-Mg alloys using ZnO powders is quite feasible. This paper analyzes the effect of temperature (750, 775 and 800°C), treatment time (0-240min) and initial magnesium content on the metallothermic reduction, to determine the variation of the concentration of Zn in the alloy. Using emission spectrometry chemical analysis, scanning electron microscopy and X ray diffraction in samples obtained as a function of temperature and treatment time, the results obtained showed that it is possible the manufacturing of Al-Zn-Mg alloys containing of up to 5.27 wt. % Zn.Some Bioinspired Ideas To Use Polymer Systems For Metal Enrichment
What are the lessons that we can learn from biology concerning metal enrichment at low temperatures and in aqueous environment? The answers to this question might give some rules for the effective design of new “metal harvesting” systems that could be effective both in metal recovery from industrial waste waters and also for metal enrichment from natural resources. The advantage of bioinspired strategies in terms of low temperature processing is obvious. Based on extensive studies that have been done mainly during the last 2 decades, the understanding of key steps, for example in mineralization of magnetic particles within magnetotactic bacteria, has progressed a lot. Microbiology and molecular biotechnology contributed very much to the deeper understanding of the molecular mechanisms that are involved in the metal enrichment processes that are part of the inorganic particle design. While microbiologists focus on biotechnological processing of metal containing species with the help of microorganism, a biomimetic approach should use a minimum or even no biofunctional compartments to realize the same goal. Material science based strategies should analyze key principles that biological species use to enrich metals and / or to control conversion of metal ions into different inorganic compound relevant in metallurgical processing. The lecture likes to discuss some ideas using polymer structures, in particular polymer microparticles to use in artificial metal enriching systems. Key questions to address are related to the following topics: 1) Preparation of artificial hollow spheres as containments for ion enrichment (against the concentration gradient!!) 2) Controlling chemical transformations and structure formation inside confined structures like microcapsules or larger structural units as liquid marbles. 3) Analytical detection of chemical reactions inside microstructures in order to achieve a process control. The interdisciplinary lecture should stimulate the discussion of possible future strategies along this line between specialists from very different fields and it will also emphasize on speculative ideas which may help to solve some problems in environmentally friendly and energy saving future technologies in metallurgy.Technology Of Secondary Niobium Raw Material Recovery
In this work, the results of researches on niobium’s sublimates electron-beam remelting processing are submitted. A problem of sublimate processing is connected with inconstancy and heterogeneity of chemical and phase compositions. Existing technologies do not provide high extraction of niobium. They are expensive and ecologically unsafe. An offered combined technology allows receiving chemical concentrates, containing 60-70% niobium, by oxidizing roasting of sublimates and subsequent steps leaching of cake by alkali and acid solutions. By methods of rational planning of the metallurgical experiment and kinetic analysis of periodic processes, semi empirical multifactor models of the sulfuric acid leaching of oxidized Al–Nb subli-mates by the solutions are obtained. The results of larger scaled laboratory tests indicate the adequacy of the obtained regularities to actual processes, as well as the possibility of practical implementation of the suggested combined technology for processing sublimates of the electron-beam remelting of niobium.