In the event of unstable CDQ operation,it would cause serious damages to the CDQ chamber refractory,like cracks and flake-offs,which needs a series of repairs,such as on the cooling section of the CDQ proper,bracket,ring beam,inner ring duct,chamber mouth,side wall of the primary deduster and high temperature expansion joint,etc.to meet the requirement for normal production.Since the conventional bricklaying takes longer time,there would be differential expansion between the existing wall and the newly-built,and the joint in between has poor strength.Therefore the new casting technology can repair the joint between the existing wall and the new wall with consistent expansion and with high strength of the brickwork in one piece.