Basic refractories magnesia-based

Refractories can be classified as acidic or basic, depending on the properties of the oxides in question. A basic refractory must not be used in contact with acid, and an acidic refractory must not be used in contact with a base. Classify magnesia and silica as acidic or basic refractories. 

Refractories can be classified in two ways. One way is based on chemical composition. The various refractories are silica (Si02), alumina (AI2O3), magnesia (MgO), chromia (Cr203), alumino-silicate, and magnesia-chromia. In the second method, the refractories are classified as acidic, basic, and neutral refractories. This classification is based on the behavior of refractories toward slags. Following is a brief discussion of each of these classes. 

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