A taphole in a blast furnace is plugged up by charging a mud into the taphole, driving a steel rod into the mud by means of an opener, stopping the driving of the steel rod into the mud when a rear end of the steel rod positions in the middle of the furnace wall and again charging a mud into a cavity behind the rear end of the steel rod embedded in the mud.

The subject invention or inventions involves providing a device which serves to substantially retard or prevent the flow of slag through a taphole of a furnace or other vessel containing molten steel, thereby improving the quality or grade of the metal. The device comprises a plug which is of such a character that when inserted in a taphole and the furnace is tilted the taphole will move to a position below the level of the layer of slag until the plug is disintegrated or destroyed by the metal to automatically allow substantially only the latter to enter and flow through the taphole or passage.

An expandable tap hole plug includes a plug comprising a cylindrical member having a circular nose and an outwardly extending flexible sidewall forming a variable obtuse angle with respect to the nose. The plug is adatepd to be oriented within a tap hole of a metallurgical vessel with the nose directed towards the interior of the vessel. An expander, in the form of a truncated cone, has a base and spokes extending outwardly from the base forming a variable obtuse angle with respect to the base. The expander is inverted relative to the plug and is attached to the plug with the spokes of the expander engaging the sidewall of the plug. The angle between the side section and base of the expander is varied so as to vary the angle of the sidewall of the plug relative to the nose thereof to block the tap hole.

A stopper plug for sealing the tap hole of a molten metal receptacle is formed of refractory materials, fibrous substances, and consumable-disintegrable materials in a hollow conical plug that is expandable in a tap hole by movement of a wedge-shaped member therein, the expanded stopper plug being capable of effectively sealing the tap hole for a predetermined time.

A plug for temporarily closing a tap hole in a metal making furnace comprises a plug body insertable into the tap hole. The plug body comprises a ceramic blanket. A plurality of biasing springs are disposed inside the blanket and are held in a retracted condition by a heat-sensitive retaining band which extends around an outer periphery of the plug. A plurality of metal strips are disposed on an outer surface of the plug to protect the blanket. When the plug is inserted into a tap hole, the band is melted by the high temperatures therein, enabling the spring to expand the plug into contact with a surface of the tap hole.