Refractory cement is made from a combination of materials like calcined alumina, ganister/silicon carbide, zirconia, ceramic clay, and lime among other materials. 

It is typically made from a mixture of refractory aggregates, bonding agents, and other materials that are designed to withstand high temperatures. The specific composition of refractory cement can vary depending on the intended use of the product, 

These materials are chosen for their ability to withstand high temperatures and their low thermal expansion coefficients, which helps to prevent cracking or other damage to the cement. Refractory cement is often used in the construction of furnaces, kilns, and other high-temperature equipment, as well as in the manufacture of firebricks and other refractory products.

Refractory cement and refractory mortar are both high-temperature resistant materials that are used in various industrial applications. However, there are some key differences between the two:

• Composition: Refractory cement and refractory mortar are made from different materials and have different compositions. Refractory cement is typically made from a mixture of refractory aggregates, bonding agents, and other materials, while refractory mortar is made from a mixture of refractory cement and fine refractory aggregate.
• Use: Refractory cement is typically used for constructing or repairing the structural elements of a furnace or other high-temperature equipment, while refractory mortar is used for filling in gaps and joints between refractory bricks or other masonry units.
• Consistency: Refractory cement is typically thicker and more paste-like in consistency, while refractory mortar is thinner and more pourable.
• Setting time: Refractory cement typically has a longer setting time than refractory mortar, which allows for more time to shape and form the material during construction.

Overall, the main difference between refractory cement and refractory mortar is in the intended use and application of the materials. Refractory cement is used for constructing or repairing the structural elements of a furnace or other high-temperature equipment, while refractory mortar is typically used for filling in gaps and joints between refractory bricks or other masonry units.