Introduction
Refractory materials are made to be chemically and physically not likely to change significantly or to
deteriorate suddenly at high temperatures (above 500oC) and are used in different types of high temperature
vessels such as linings for furnaces, kilns, converters, reactors, ladles. Depending on the working and
application conditions, refractories must have certain properties, for example, they must have a certain amount
of resistance to thermal shocks, be chemically inert and / or have a specific value of thermal conductivity and
thermal expansion coefficient (1).
Refractories are one type of ceramic material that has the potential to maintain its physical and
chemical properties when used at high temperature. Because of its unique properties it can be suitable for the
requirements of production factories such as metal casting plants, The primary task of these heat-resistant
materials in metal casting is to isolate the product of high temperature from the external environment or as a
container to place the dissolved product. Therefore, knowledge of the properties of heat-resistant materials is
necessary in the metal casting industry(2).
Refractories are mostly used in basic metal industries. In the steel-making process, the molten iron from
the blast furnace is purified from the impurities including C, S, P, Mn, etc(3). One of the basic conditions that
refractories should be characterized by refractory slag.In the aluminum metal industry, the requirements of the
thermal materials are completely different from those of the thermal materials used in the steel industry, for
example, in the process of refining the aluminum, although the temperature used is lower compared with the
heat in the steel industry, but there is an important problem is the penetration in refractories. Hence, the
refractory should be choosing so that it has a non wetting characteristic to molten aluminum(4).