Hot briquetted iron

Host-guest chemistry Hostile environments Hot briquetted iron... 

Direct Reduction. Direct reduction processes are distinguished from other ironmaking processes in that iron oxide is converted to metallic iron without melting. Because this product, called direct reduced iron (DRI), is soHd, it is most suitable for melting in an electric arc furnace (EAF) as a substitute for scrap (see Furnaces, electric). The briquetted form of DRI, hot briquetted iron (HBI) is used when the product is to be transported. Briquetting increases density and chemical stabiUty. The predominant direct reduction processes (MIDREX and HyL III) are based on natural gas as a fuel and reductant source. They are economically attractive in regions where natural gas is cheap and abundant, especially if iron ore is available nearby (see Iron BY DIRECT reduction). ... 

DRI can be produced in pellet, lump, or briquette form. When produced in pellets or lumps, DRI retains the shape and form of the iron oxide material fed to the DR process. The removal of oxygen from the iron oxide during direct reduction leaves voids, giving the DRI a spongy appearance when viewed through a microscope. Thus, DRI in these forms tends to have lower apparent density, greater porosity, and more specific surface area than iron ore. In the hot briquetted form it is known as hot briquetted iron (HBI). Typical physical properties of DRI forms are shown in Table 1. 

Scrap metal Direct reduced iron Hot briquetted iron Cold pig iron Hot metal... 

SPIREX A DR process for making iron powder or hot briquetted iron from iron ore fines. Three stages are used. The first is a circulating fluidized bed preheater whose turbulent conditions reduce the particle size of the ore. The second and third stages achieve the reduction in fluidized beds, fed by reducing gases from a MIDREX reformer. Developed by Midrex Direct Reduction Corporation and Kobe Steel. A demonstration plant was scheduled to be built at the Kobe Steel plant in Venezuela in 1997. 

Host microorganisms, for industrial enzyme production, 10 264-265 Host oxide lattice structure, 19 403 Hot air food driers, 12 85 Hot and cold composite curves, 13 222 Hot-box resins, 12 273 Hot briquetted iron (HBI), 14 492-494, 509 21 412... 

All true (producing exclusively for export) merchant DR plants use roller presses to produce hot briquetted iron (HBI) although other methods of densification and shaping are also feasible (Section 13.3, Patents 5-9). Profitable merchant plants use ores that are more likely to produce fines or avoid the additional cost of procuring high-quality lump ore or pellets altogether by feeding natural ore fines or concentrates direcdy into fluid-bed reactors. As mentioned before, such facilities require hot den-... 

Fig. 6.9-7 Micrographs comparing the structures of direct reduced iron (DRI, left) and hot briquetted iron (HBI, right) (Section 13.3, ref. 146)...

Figure 6.5.3 World steel production and metallic charge (SM Siemens Martin, HBI hot briquetted iron, BF blast furnace. Adapted from Schmoele and Luengen (2007).

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