Contaminated aluminium scraps are often recycled in Tilting Rotary Furnaces under a salt flux. The salt flux has three main functions: protect the metal surface against oxidation, promote the coalescence and remove the impurities (mainly oxides) from the metal bath. The last aim leads to an evolution of the salt flux during the recycling process: the oxide content continually increases, the salt flux is therefore changed into a salt slag and the salt properties are altered. This paper focuses on coalescence of aluminium chips in salt slag in TRF and the influence of cryolite. Different salt slags were synthetized from salt and non-metallic solid residue from the recycling of salt slag. The experiments were conducted in a lab-scale tilting rotary furnace and several salt slag compositions were considered. It was shown that the coalescence is linked to oxide and cryolite content of the salt slag.
展开▼
