Coil mortar has properties such as high strength, high density, and high insulation. It is a corundum-based mortar specially designed to protect the coils of coreless induction furnaces. Coil mortar has good viscosity and is very easy to apply. The smooth surface formed by applying it on the coil can buffer the expansion and contraction of the working lining. In addition, coil mortar can also effectively prevent the leakage of molten metal and protect the coil from being punctured by molten metal.