A blast furnace for ironmaking production wherein iron ore is at least partly reduced by a reducing gas which is injected in the stack of the blast furnace. The blast furnace includes an external and an internal wall, having a thickness T.sub.int, in contact with matters charged into the blast furnace. The thickness T.sub.int of the internal wall is substantially constant above and below the injection area of a reducing gas.

A metallurgical vessel structure and method is provided for producing low-impurity Magnesia-Carbon reclaimed aggregate suitable for reuse in the production of high purity Magnesia-Carbon refractory. A metallurgical vessel is assembled with a non-reactive or chemically similar backup lining. The entire height of the working lining wall is Magnesia-Carbon brick suitable for reuse. The working lining is exposed to a metal making high temperature process, and the working lining is sequentially demolished. Due to the assembly of vessel, metallurgical practice, and ease of demolishing the vessel, there is little to no need for sorting, such that the used Magnesia-Carbon brick are easily converted into low impurity Magnesia-Carbon reclaimed aggregate. A refractory composed of low-impurity Magnesia aggregate reclaimed from the method is also contemplated.

This invention refers to a technically and economically viable process for recovery of relevant metallic and non-metallic contents from mining residues, particularly the bauxite residue, using it in its integral form. Such a process route uses energy from microwaves, assisted leaching and logic sequencing of steps that allow a technically and economically viable removal of components from the bauxite residue, particularly the residue from the Bayer process. The invention also refers to a microwave reactor that is appropriate for performing the above-mentioned process, as well as to a method for heating a mining product.

The present invention relates to inorganic fibres having a composition comprising: 61.0 to 70.8 wt % SiO.sub.2; 28.0 to 39.0 wt % CaO; 0.10 to 0.85 wt % MgO other components, if any, providing the balance up to 100 wt %, The sum of SiO.sub.2 and CaO is greater than or equal to 98.8 wt % and the other components comprise less than 0.70 wt % Al.sub.2O.sub.3, if any.

A refractory ring structure for forming a section of an inner wall or liner of a metallurgical vessel is provided. The refractory ring structure comprises a continuous top surface; a continuous bottom surface; a continuous arcuate inner surface extending from the top surface to the bottom surface and defining a cavity; a continuous arcuate outer surface opposite the inner surface and extending between the top surface and the bottom surface; and a continuous protrusion or a plurality of protrusions extending from the inner surface for lifting the ring structure. The refractory ring structure comprises a heat resistant, refractory material suitable for use in the inner wall of a metallurgical vessel. Also provided herein are a metallurgical vessel comprising a refractory ring structure as disclosed herein, and a method for providing or replacing all or a section of a refractory inner wall or liner of a metallurgical vessel.

A modular dome structure (5) for a masonry oven, which includes a plurality of interlocking wall modules (60) abutting one another to form a wall of the dome and a base (7) upon which the wall modules are mounted. Each wall module (60) is formed of a plurality of blocks (63) hingedly interconnected together and shaped so as to form an arch segment of the dome wall when facing surfaces of adjacent blocks (63) of the wall module (60) abut and interlock with one another.

Thermal storage unit including: a receptacle including orifices allowing a heat-transfer fluid to be introduced into and extracted, and a stack of bricks, arranged in the receptacle in superposed strata, each stratum having lower and upper large faces and defining a plurality of ducts opening via lower and upper openings, the stack including a pair of strata of a lower and upper stratum, the upper and lower large faces of the lower and upper stratum being separated to define a passage, placing an upper opening of a lower duct of the lower stratum in fluidic communication with at least one lower opening, entirely offset with respect to the upper opening, of at least one upper duct of the upper stratum, the lower large face of the upper stratum closing off, at least partially, the upper opening, when the upper opening is observed, along its axis, from the lower duct.

A furnace stave comprising a plurality of internal channels or conduits for circulating cooling fluid through the stave; an inlet and an outlet channel associated with each internal channel or conduit; wherein one of the internal channels or conduits is disposed in a protrusion from the stave.

A furnace stave comprising a plurality of internal channels or conduits for circulating cooling fluid through the stave; an inlet and an outlet channel associated with each internal channel or conduit; wherein one of the internal channels or conduits is disposed in a protrusion from the stave.

The invention relates to a conveying system for conveying a material to be conveyed along a conveying path. The conveying system includes a conveying chamber in which the conveying path is arranged. At least one component of a conveying mechanism for conveying the material to be conveyed is arranged outside the conveying chamber. The conveying mechanism includes a traction drive having at least one traction element by means of which carrying elements can be moved in order to convey the material to be conveyed. The carrying elements are arranged in the conveying chamber and protrude through a through-opening out of the conveying chamber. Inside the conveying chamber and/or in the region of the through-opening, the surfaces of the carrying elements are at least partially provided with a thermal insulation material.