A burner for a metal-melting furnace can releasably receive a tapered plug in sealing engagement with an access passage aligned with an air passage. The burner may be configured to extend through a wall of the metal-melting furnace so that the air passage is through a front face within the furnace and so that the access passage is through a rear face outside of the furnace. The access passage may be aligned with the air passage to permit a rigid structure to be passed through the burner from outside the furnace to dislodge build-up of solidified metal from the air passage. The tapered plug may be moveable between a sealing configuration of being received in a seat to seal the access passage during burner operation and a cleaning configuration of being removed from the seat to expose the access passage for insertion of the rigid structure.

The present disclosure provides a cutting device. The cutting device includes a shaft, two or more gussets, two or more radial cutting members, and a circumferential cutting member. The shaft extends from a first end to a second end. The two or more gussets include at least a first gusset and a second gusset extending radially away from the shaft. The two or more radial cutting members include at least a first radial cutting member axially supported by the first gusset and a second radial cutting member axially supported by the second gusset. The circumferential cutting member is axially supported by each of the first gusset and the second gusset.

A burner for a metal-melting furnace can releasably receive a tapered plug in sealing engagement with an access passage aligned with an air passage. The burner may be configured to extend through a wall of the metal-melting furnace so that the air passage is through a front face within the furnace and so that the access passage is through a rear face outside of the furnace. The access passage may be aligned with the air passage to permit a rigid structure to be passed through the burner from outside the furnace to dislodge build-up of solidified metal from the air passage. The tapered plug may be moveable between a sealing configuration of being received in a seat to seal the access passage during burner operation and a cleaning configuration of being removed from the seat to expose the access passage for insertion of the rigid structure.

A slag door for a melting furnace for the production of steel is suitable to be associated with an aperture provided in a lateral wall of the melting furnace and to cooperate with a slag channel provided inside the melting furnace itself.

A slag door arrangement (10) for a metallurgical furnace (1) includes a furnace vessel (2) with a slag tunnel (8) having a rectangular opening cross section extending laterally through the furnace vessel (2). A pivoting movement of the slag door about a horizontal pivoting axis and a lifting movement of the slag door in a direction perpendicular to the horizontal pivoting axis are independent of each other. A method for cleaning a slag opening of such a metallurgical furnace (1) includes pivoting the slag door to perform a cleaning movement from a position of the slag door in the slag tunnel near the interior of the furnace towards the outside of the furnace out of the slag tunnel at controllably different distances (clearances) from the bottom of the slag opening or of the slag tunnel.

An apparatus for removing a blockage in a solids injection lance extending into a direct smelting vessel The solids injection lance has a single inlet coupled to a section of supply line that conveys gas and solids to the solids injection lance and that is upstream and co-axial with the solids injection lance. The apparatus has a tool that extends through the supply line section and the solids injection lance to remove a blockage of solid material and an assembly for advancing the tool through the solids injection lance and the supply line section to the blockage from an upstream side of the blockage.

A method of removing a blockage in a solids injection lance under normal operating conditions of a direct smelting vessel is disclosed. The direct smelting vessel contains a bath of molten metal and slag and the solids injection lance extends into the direct smelting vessel and has an outlet end that is submerged in the molten slag. The solids injection lance further has a single inlet coupled to a section of supply line that conveys gas and solid feed material to the solids injection lance. The method comprises (a) advancing a blockage-removing tool through the supply line section and through the solids injection lance to an upstream side of the blockage, (b) operating the tool under elevated gas pressure conditions to remove the blockage such that solid feed material and gas are able to flow through the solids injection lance. The method further comprises (c) retracting the tool from the solids injection lance and the supply line section. Also disclosed is an apparatus for removing a blockage in a solids injection lance extending into a direct smelting vessel.

A device for producing expanded granulated material from grains of sand with an expanding agent includes a furnace with a furnace shaft, which has upper and lower ends. A conveying section extends between the ends and passes through separately-arranged heating zones in a conveying direction. At least one feeder charges at least the unexpanded material into the furnace shaft at one end toward the other end. At least one rotatable shaft insert is arranged at least in sections in the furnace shaft and has at least one scraper blade forming with an inner wall of the furnace shaft at least one gap having a gap width and being designed, during rotation of the at least one shaft insert in an operating state of the device, to remove caking on the inner wall at least in sections if a thickness of the caking is greater than the respective gap width.

A burner for a metal-melting furnace can releasably receive a tapered plug in sealing engagement with an access passage aligned with an air passage. The burner may be configured to extend through a wall of the metal-melting furnace so that the air passage is through a front face within the furnace and so that the access passage is through a rear face outside of the furnace. The access passage may be aligned with the air passage to permit a rigid structure to be passed through the burner from outside the furnace to dislodge build-up of solidified metal from the air passage. The tapered plug may be moveable between a sealing configuration of being received in a seat to seal the access passage during burner operation and a cleaning configuration of being removed from the seat to expose the access passage for insertion of the rigid structure.

An apparatus for removing a blockage in a solids injection lance extending into a direct smelting vessel The solids injection lance has a single inlet coupled to a section of supply line that conveys gas and solids to the solids injection lance and that is upstream and co-axial with the solids injection lance. The apparatus has a tool that extends through the supply line section and the solids injection lance to remove a blockage of solid material and an assembly for advancing the tool through the solids injection lance and the supply line section to the blockage from an upstream side of the blockage.