A method of operating a plant having a furnace including at least two vertical shafts connected by an overflow duct, wherein at least one burner is arranged above the overflow duct in each case such that the burner gases therefrom flow downward in burning operation of the respective shaft. A cooling gas supply is provided beneath the overflow duct in each case such that, in combination with the operation of a burner in the burner-operated shaft, the burner gas flowing downward is deflected in the direction of the overflow duct by the cooling gas ascending in the burner-operated shaft, and a supply of cooling gas is adjusted such that the temperature of the burner charge through which the burner gas flows at least in the burner-operated shaft is kept above the deacidification temperature thereof.

Smelting metalliferous feed material process forming molten metal in smelting apparatus including smelt cyclone above and communicating with smelting vessel to contain molten metal and slag bath, including: partially reducing and melting feed material in smelt cyclone, allowing the molten partially reduced feed material flow downwardly into vessel, supplying oxygen-containing gas and carbonaceous material to vessel, smelting molten partially reduced feed material in molten metal and slag bath in vessel forming molten metal discharged from vessel and reaction products projected upwardly from molten bath, at least partially combusting combustible materials in reaction products in vessel space above molten bath, supplying oxygen-containing gas to smelt cyclone. Further combusting reaction products in smelt cyclone, discharging from smelt cyclone offgas including reaction products, supplying oxygen-containing gas into offgas duct upstream high temperature section combusting remaining offgas combustible materials while sufficiently hot for safe ignition and avoiding downstream burner-managed incineration.

A furnace may include at least two vertical shafts, each of which may have at an upper end thereof an inlet for material to be burnt and at a lower end thereof a burnt material outlet. The inlet and the outlet may be connected by a transfer channel. In each case, at least one main burner may be positioned above the transfer channel, and a cooling gas inlet may be positioned below the transfer channel. At least one additional burner may be positioned below the transfer channel in each of the shafts. Such a furnace can be operated such that the material to be burnt in the currently fired shaft is at least partially calcined in a main burning zone above the transfer channel, and then thermally aftertreated in an additional burning zone positioned between the transfer channel and the additional burner.

A furnace may include at least two vertical shafts, each of which may have at an upper end thereof an inlet for material to be burnt and at a lower end thereof a burnt material outlet. The inlet and the outlet may be connected by a transfer channel. In each case, at least one main burner may be positioned above the transfer channel, and a cooling gas inlet may be positioned below the transfer channel. At least one additional burner may be positioned below the transfer channel in each of the shafts. Such a furnace can be operated such that the material to be burnt in the currently fired shaft is at least partially calcined in a main burning zone above the transfer channel, and then thermally aftertreated in an additional burning zone positioned between the transfer channel and the additional burner.

The present invention relates to a waterless system and method for cooling a metallurgical processing furnace. Supercritical carbon dioxide (sCO.sub.2) is used as a coolant, as opposed to water, which provides several advantages. For example, sCO.sub.2 can be used at higher temperatures, the risk of an explosion (with use of water) is eliminated, there are no problems with regard to reverse solubility of water at higher temperatures that can foul passageways, and smaller cooling passages can be used thus reducing the cost of cooling panels. A system is disclosed which uses a reservoir to store the sCO.sub.2, a compressor or pump to cause the delivery of the sCO.sub.2 to cooling passages in the furnace, a pressure reducing valve or a turbine to decrease the pressure of the sCO.sub.2, and a heat exchanger to cool the sCO.sub.2 to a liquid state as the sCO.sub.2 travels back to the reservoir.

A device for producing expanded granulated material from mineral material in the form of grains of sand with an expanding agent includes a furnace with a furnace shaft, having an upper end and a lower end. A conveying section extends between the two ends and passes through a number of heating zones arranged separately from one another in a conveying direction. The device also includes at least one feeder in order to charge at least the unexpanded material into the furnace shaft at one of the two ends in the direction of the other of the two ends. At least one directing element is at least partly arranged in the furnace shaft and forms a gap with an inner wall of the furnace shaft, at least in the region of one of the two ends. The at least one feeder is designed for charging the material into the gap.

All of a cast-iron or cast-copper stave cooler's weight is supported inside a furnace containment shell by a single gas-tight steel collar on its backside face. All the coolant piping in each cooler has every external fluid connection collected and routed together through the one steel collar. A wear protection barrier is disposed on the hot face. At least one of horizontal rows of ribs and channels retain metal inserts or refractory bricks, or pockets that assist in the retention of castable cement and/or accretions frozen in place from a melt, or an application of an area of hardfacing that is welded on in bead, crosshatch, or weave pattern.

All of a cast-iron or cast-copper stave cooler's weight is supported inside a furnace containment shell by a single gas-tight steel collar on its backside face. All the coolant piping in each cooler has every external fluid connection collected and routed together through the one steel collar. A wear protection barrier is disposed on the hot face. At least one of horizontal rows of ribs and channels retain metal inserts or refractory bricks, or pockets that assist in the retention of castable cement and/or accretions frozen in place from a melt, or an application of an area of hardfacing that is welded on in bead, crosshatch, or weave pattern.

A device for mounting and/or dismantling staves on/from an inner wall of a shaft furnace, the device including a circular monorail for supporting at least one stave positioning hoist, where the monorail is divided into at least four separate arc portions, where each arc portion is connected to a neighboring arc portion by means of a rotatable connection, the arc portions are moveable between an unfolded position, in which the arc portions form a circular monorail, and a folded position, in which the overall size of the monorail is, in one direction, reduced.

A device for cooling the supporting trunnions of a distribution spout of a charging installation of a shaft furnace, wherein the spout is mounted pivotably about a horizontal axis on a shell coaxial with the furnace and the spout is attached rotatably to the trunnions driven in rotation by a drive component. The trunnions are directly attached for rotation by their ends to output shafts of reduction gears and include internal cooling channels. The cooling device includes feed and return ducts for the cooling water circulating in the internal channels. The feed and return ducts are connected to the trunnions by connectors fixed to the cylindrical surface of the trunnions. The feed and return ducts are arranged to permit rotational displacement of the connectors about the pivot axis of the spout during pivoting of the spout, in particular by passing through oblong slots extending circumferentially in the wall of bearings supporting the driving reduction gears.