Abstract: A method for cleaning of a roller screen transporting and screening particles by means of at least three rotating rollers. The rollers are installed in succession at given clearances and arranged transversally in relation to the transport direction of the particles to screen a desired range of particle sizes. At least one roller changes its circumferential velocity and/or its rotational direction over time at defined time intervals for defined time periods such that for this defined time period for at least one pair of neighbored rollers one roller has a higher circumferential velocity than the other and/or both rollers roll in opposite rotational directions.

Abstract: A method for cleaning of a roller screen transporting and screening particles by means of at least three rotating rollers. The rollers are installed in succession at given clearances and arranged transversally in relation to the transport direction of the particles to screen a desired range of particle sizes. At least one roller changes its circumferential velocity and/or its rotational direction over time at defined time intervals for defined time periods such that for this defined time period for at least one pair of neighbored rollers one roller has a higher circumferential velocity than the other and/or both rollers roll in opposite rotational directions.

Abstract: A method for charging pallet cars of a traveling grate for the thermal treatment of bulk material includes in a first step a first layer is applied as a hearth layer on a grate surface of the pallet car. In at least one second step a second layer at the same time or successively is applied as a side layer on two opposed side walls of the pallet car and a third layer is applied as green pellet layer between the side layers and on the hearth layer. The pellets used for the grate and the side layer differ in terms of their diameter and size distribution.

Abstract: A method for charging pallet cars of a traveling grate for the thermal treatment of bulk material includes in a first step a first layer is applied as a hearth layer on a grate surface of the pallet car. In at least one second step a second layer at the same time or successively is applied as a side layer on two opposed side walls of the pallet car and a third layer is applied as green pellet layer between the side layers and on the hearth layer. The pellets used for the grate and the side layer differ in terms of their diameter and size distribution.

Abstract: The direct reduced iron (DRI) which for at least 80 wt-% has a grain size of not more than 3 mm is melted in an electric arc furnace. The furnace contains a bath of liquid iron. During the operation of the furnace a foamy slag layer is formed on the bath and the DRI falls by gravity through at least one movable lance into the foamy slag layer on the iron bath. Preferably, the distance of the aperture of the lance to the iron bath is kept practically constant.

Abstract: The granular sponge iron is supplied to a roller press at temperatures of 600 to 850.degree. C. for molding the hot briquets. There is produced a strip structure of sponge iron containing formed hot briquets, which are arranged at a distance from each other. By smashing the strip structure, the hot briquets are separated from each other, so that fragments of the strip structure are obtained. The hot briquets and at least part of the fragments are cooled to temperatures in the range from 20 to 400.degree. C., and the cooled briquets and fragments are passed through a rotary drum. In the rotary drum, fine-grained fines of the briquets and fragments are produced. Subsequently, these fines are separated from the briquets and fragments, as they exhibit a pyrophoric behavior.