Tap hole clay or mud gun mass are required to plug the Blast Furnace tap hole. It has many technological parameters, which must be evaluated to design and manufacture a good tap hole clay. In the physical requirements, a tap hole clay mass must close the tap hole smoothly, and maintain the tap hole length for the duration of the tap hole closure. Further, it must open easily using the existing drill hole machine available in the plant. The tap hole clays are subjected to fluctuating high temperatures, thermal shock and are prone to early erosion, and therefore, to obtain a trouble-free cast, a good and strong tap hole clay mass of requisite physical and chemical properties are required. The most important physical need is to achieve a constant tap hole length, which also helps to operate the Blast Furnace at high pressure, and thereby increasing the productivity of the hot metal products. The most important chemical parameters are the design of a stable Tar-Resin bonding material up to high temperature, and to stabilise the "Mushroom" where erosion by hot metal and slag is maximum. For this, it is necessary to induct Thermal Resistant and Corrosion Resistant material into the tap hole mix. This paper deals with the essential high temperature properties that are required to manufacture a good workable tap hole clay. Further, it is necessary to examine the various parameters that affect the working of the tap hole clay, with respect to the application of the product in the harsh working environment of the Blast Furnace. In the tap hole clay, the results of which are presented in this paper, have been developed after extensive laboratory trails and Blast Furnace field trails. These tap hole clays or mud gun mass have been successfully applied in several Blast Furnaces of the southern region of India.
展开▼
