Voest-alpine Aktiengesellschaft

Vereinigte Osterreichische Eisen- Und Stahlwerke-alpine Montan

Gunther Saiger

Horst Sulzbacher

Kurt Stift

In a process for treating porous iron-containing particles, in particular iron sponge, performed for preventing reoxidation and/or corrosion during storage and transport it is proposed to roll the iron sponge particles in dust-shaped calcined lime stone (lime dust) and then to humidify the particles with an amount of water which is smaller than required for completely hydrating the calcined lime stone. Hydrophobing additives such as stearates, oleates, paraffins, oils, soaps or waste materials containing fats and soaps are added to the dust-shaped calcined lime stone, said hydrophobing additives being preferably added to the slaking water in form of water-soluble compounds such as ammonium stearate. The hydrophobic additives can be mixed with the calcined lime stone and optionally iron oxide dust. The process can also be performed such that two coatings are applied to the iron sponge particles to be treated in which case the hydrophobing additives are added within the second coating only.

Process for treating iron sponge

For protecting iron sponge particles against reoxidation and/or corrosion a coating comprising CaO as well as iron or iron oxides as adhesion promotor is applied onto the iron sponge particles. Water is subsequently sprayed onto this coating whereupon a second coating of a mixture of dust-shaped CaO and a carbon carrier is applied. This second coating is subsequently humidified with a smaller amount of water than would be necessary for completely slaking the CaO contained within the second coating.

Process for treating metallic starting materials for smelting plants,

A process for treating sponge iron to protect it against reoxidation and/or corrosion during storage and transit comprising the steps of tumbling sponge iron which is in particle form with a pre-prepared blend of caustic lime powder and an adhesion promoting additive selected from the group consisting of iron oxide or mixtures thereof with iron to produce a coated product, the blend containing 1 to 20% by weight iron oxide; and then moistening the coated product with an amount of water less than the amount of water required for complete hydration of the caustic lime.

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Trofaiach, Austria

Gunther Saiger