The spinel structure refractory for intermediate frequency furnace developed by our company is a kind of neutral refractory,which is composed of high- purity fused corundum and high-purity fused magnesia sintered at 1680C in strict proportion,forming a stable phase with excellent slag and metal erosion resistance.High temperature,good volume stability,strong thermal impact resistance,non-stick slag and smooth lining surface are the important characteristics of the material.At the same time,this series of materials have the characteritics of high strength and stable backing layer,which can prevent steel puncture and leakage to the maximum extent.For conventional quartz,liquid phase occurs between refractory particles at 1600℃,so theoretically it can only be used to melt cast iron and low-melting non-ferrous metals.