The main purpose of large fabric is to repair the damage of converter trunnion, large surface and around the steel outlet. It is made of high quality magnesia as the main raw material, plus special binder, sintering agent, coagulant promoter and through special production process. There are two kinds of charging materials: carbon charging and non - carbon charging. The carbonaceous charging has the characteristics of good fluidity, high adhesion strength, erosion resistance and long service life. Compared with the carbonaceous patching materials, the non-carbonaceous patching materials have better fluidity, less environmental smoke, shorter sintering time and less pollution.