Abstract: A method and apparatus for the production of prereduced iron ore, DRI, sponge iron or the like by the gaseous reduction of iron-oxide containing particles in a reduction system which comprises a preheating device for the iron ore particles. The preheating device preserves the strength of the iron ore particles through the reduction system by preheating the particles with non-reducing (or preferably oxidizing) gas, whereby the DRI or like material produced is stronger than if it were processed in a reduction reactor without said preheating device. The invention thereby avoids sticking and fines production problems which some iron ores cause in the reduction reactor. The preheating device also produces other advantages in the reduction system as, for example, that the reducing gas reaches a higher degree of oxidation in the reduction reactor whereby the productivity of the reduction system increases as a result of the decreased amount of reducing gas as well as the decreased residence time required.

Abstract: Method and apparatus for pneumatically transporting solid and abrasive particulate materials at high temperature, by means of a carrier gas through a plurality of co-axial straight pipes. The pipes are maintained under constant tension by applying a force across at least one expansion joint coupling said pipes in order to maintain said pipes straight against the forces acting on said pipes which tend to cause bending and deformation thereof, as for example: thermal elongation, the weight of the solids conveyed through said pipes, the friction forces between said pipes and its supporting frame, and the pressure of the carrier gas inside said pipes. The constant tensioning force may be applied for example, by means of hydraulic cylinders in combination with a telescopic water-cooled sleeve.