| The present study is concerned with the development of novel techniques of purifying recycled aluminum which may be less expensive than the present techniques (electrochemical refining, dilution by addition of purer metal,...). It has been proposed to remove the impurities as chlorides, firstly by adding a molten salt and secondly by bubbling a mixture of an inert gas (argon) and chlorine in the liquid metal. To study the possible chemical exchanges for the system metallic phase-molten salt-gas, thermodynamic databases were prepared for the two liquid phases using the F*A*C*T thermodynamic database computing system, which has been under development for many years in the Centre for Research in Computational Thermochemistry (CRCT) at the Ecole Polytechnique de Montreal.; For the metallic phase, the main impurities that are considered are iron Fe, potassium K and sodium Na. We also consider magnesium Mg, which is an alloying element for beverage cans.; For the molten salt, the species that are considered are the following: NaCl, KCl, AlCl{dollar}sb3{dollar}, MgCl{dollar}sb2{dollar}, FeCl{dollar}sb2{dollar} and FeCl{dollar}sb3{dollar}. The fifteen binary systems, the basic region of the ternary system NaCl-KCl-AlCl{dollar}sb3{dollar} and the ternary liquids NaCl-KCl-MgCl{dollar}sb2{dollar} and NaCl-KCl-FeCl{dollar}sb2{dollar} were studied. (Abstract shortened by UMI.)... |
