Overview Primary ProductionAluminosilicate castables, which are widely used in aluminum transformation furnaces, are susceptible to chemical reactions between molten aluminum and the furnace refractory lining. To prevent those reactions, commercial additives such as BaSO 4 , CaF 2 , and AlF 3 are generally added in castables. This article presents and analyzes the effect of various amounts of the above additives as well as the influence of pre-firing temperatures on the corrosion behavior of an aluminosilicate low cement castable matrix in contact with liquid Al5%Mg alloy.

No abstract

No abstract

No abstract

The corrosion of aluminosilicate refractories by molten aluminum, such as in melting and holding furnaces, generally leads to the formation of an alumina deposit on the refractory. In the presence of alkalies and under a reducing atmosphere the extent of corrosion is increased. This could he related to the transformation of the alumina to sodium aluminate, whose formation kinetics are increased under a reducing atmosphere, promoting the formation of aluminum nitride. In melting and holding furnaces, the alkalies could originate from the presence of a cryolitic bath in the metal charge and/or from the refractories. In the latter case, it was shown that aluminum nonwetting refractory castables containing aluminum fluoride as the nonwetting agent could lead to severe corrosion in the above applications if their alkali content is such that it promotes the formation of /3-alumina. [