Abstract: This invention provides chemical processes for the treatment of industrial steelworks waste, especially those from an electric arc furnace, called “flue dust,” to allow for the subsequent recovery of metals (e.g. zinc and iron) from the dust. The main purposes of the process are: (i) the opening of the crystalline webs (zinc ferrite) originally formed in the flue dust, with the simultaneous production of soluble sulfates in aqueous medium; (ii) and the destruction of possible dioxins without subsequent regeneration. The processes encompass production of salts or sulfates of the metals in the flue dust, utilizing concentrated sulfuric acid and reagents or catalysts by dry medium, at normal pressure and moderate temperatures. The processes promotes reaction of sulfuric acid with elements found in the flue dust to maintain a homogenous mixture without the presence of water, and prevent agglomeration of the particles through the addition of secondary reagents and catalysts.