1. High temperature resistance. The heating temperature of the aluminum melting furnace is generally between 900 and 1300 ℃, and the refractory material should have the property of not being easy to melt under the action of high temperature.

2. The high temperature structure is strong. Various refractory materials begin to soften before melting, thereby reducing structural strength.

Therefore, the refractory material should also have the property of not being easy to soften at high temperature under the load of the furnace masonry or other mechanical vibration.

3. The volume should be stable when used for a long time under high temperature. In the long-term high temperature use of refractory materials, the physical and chemical changes inside the masonry will produce volume shrinkage or volume expansion. Whether it is shrinkage or expansion, it will cause damage to the masonry. Therefore, refractory materials are required to be stable in volume at high temperatures.

4. Good resistance to rapid cold and rapid heat. During the use of the aluminum melting furnace, due to the sudden temperature change, the temperature of each part of the material is uneven, and the internal stress of the masonry will cause the material to crack and peel off. Therefore, refractory materials should have good resistance to rapid cold and heat to resist such damage.

5. It does not pollute the aluminum melt, and it is not corroded by the aluminum melt. During the use of refractory materials, one of the main reasons for its damage is corrosion due to the effect of slag, metal and furnace gas. Therefore, refractory materials must have the ability to resist this erosion. Similarly, the refractory material in contact with the molten metal should not chemically react with the molten aluminum to contaminate the molten metal during use. Otherwise, it will be impossible to ensure the required melting quality.

6. Low air permeability and low heat loss. Air permeability is one of the indicators for evaluating the density of refractory products. In some cases, it can determine the service life of the products; in addition, the aluminum melting furnace consumes a lot of heat energy during the working process, and it is always the user's expectation to improve the thermal efficiency of the furnace. Hope, therefore, in addition to thermal insulation materials, refractory materials are also required to have a certain thermal insulation effect.

7. It has a certain shape and correct size, and the price is low. When refractory materials are supplied in the form of bricks, the external dimensions of the refractory bricks are required to be regular with small tolerances. Because the bricks are filled with refractory mud, and the structural strength of the refractory mud is lower than that of refractory materials, irregular refractory bricks increase the filling, thereby reducing the life of refractory materials.

In fact, there is no refractory material that can meet all the above requirements. Shaped and unshaped refractory products need to be used together. Therefore, the design of the furnace and the user should reasonably select refractory materials for each part according to specific conditions.