[Chemical and technological caracterization of some secondary pulverous materials recycled in metallurgy]

Putting in practice the recycling projects of the damaging secondary powder products as dust, scale (mixture of oxides - fabrication defect appearing at rolling) or sand resulted in steel industry effluents removal, needs to be characterized from physical, chemical and technological point of view: This paper aims to realise a new classification of the damaging material and new definitions for their characteristics. The proposed groups are: producing characteristics, impact characteristics, removal characteristics and recycling valorisation characteristics. To underline the technological importance of the used characteristics as work instruments has been programmed experimental researches regarding the diminishing of the recycling of the dust and the sand obtained after the electric arc furnace gas removal and scale from rolling. The characteristics of recycling valorisation have been assessed: chemical composition and Zn assimilation ratio in the steel, the efficiency in liquid steel, the degree of replacing the scrap iron and the recycling chemical composition.