Formalization of concepts of the processes occurring in melting aluminum rejects in tilting rotory furnaces.

The experience of aluminum remelting in a tilting rotor furnace (TRF) showed that the present level of understanding about the melting process is not enough to explain the observed effect and to control it consciously. Certain uncontrolled losses of metal result from that. The attempts to optimize the economic parameters (to reduce the melting time, reduce the amount of the used fluxing agent) from relatively rich aluminum raw materials (50 and more per cent of metal) sometimes result in nothing. hi the language of metallurgists it is called the 100% melting loss. It is implied that all the metal has burned out, i.e. has passed into an oxide state. In fact it was found out in the studies of the refused slag that the most part of the metal is left in slag in the form of small spherical drops covered with the oxide film. Such effects made it necessary to pay more attention to the processes, occurring in this situation The phenomenological model proposed for consideration is the result of generalization of visual observation of the processes of re-melting different types of aluminum raw materials at the rotor inclined furnaces and the analysis of the results of the laboratory researches of the initial raw materials, refused slag and dust in the exhaust gases. The stated fact is mainly related to melting different types of aluminum rejects in the mode of "dry" melting with lower amount of the fluxing agent when secondary dross is in the loose dispersed state. In the process of melting in the environment of permanently mixed furnace feed the solid aluminum can pass into different states and simultaneously be in an oxide form, small railing, drops, mess and swamp and be removed with the exhaust gases in the form of dust and volatile compounds formed in the result of chemical interaction of aluminum with the fluxing agents. In the model are considered certain possible reactions of transition of the metal from some states to other ones at different stages of melting for different types of raw materials. The reactions determining the process of melting of different types of raw materials were tabulated.