Process for treating iron sponge

摘要

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.