Industrial steelmaking (EAF) flue dust was characterized in terms of chemical and phase compositions, leaching behaviour in 20% sulphuric acid solution as well as leaching thermal effect. Waste product contained about 43% Zn, 27% Fe, 19% O, about 3% Pb and Mn and lesser amounts of other elements (Ca, Si, Mo, etc.). It consisted mainly of oxide-type compounds of iron and zinc. Dissolution of metals (Zn, Fe, Mn) from the dust was determined in a dependence of solid to liquid ratio (50-200 g/L), temperature (20-80oC) and leaching time (up to 120 min). The best result of 60% zinc recovery was obtained for 50 g dust/L and a temperature of 80oC. Leaching of the material was an exothermic process with a reaction heat of about –318 kJ/kg. Precipitation purification of the solution was realized using various ratios of H2O2 to NH3aq. A product of this stage was hydrated iron(III) oxide. Final solution was used for zinc electrowinning. Despite that pure zinc was obtained the highest cathodic current efficiency was only 40%.

Codeposition of antimony and tin from acidic chloride and chloride-sulfate baths was investigated. The calculations of distribution of species showed domination of neutral SnCl2 and anionic SbCl4 – complexes in chloride solution, while in the presence of sulfate ions neutral SnSO4 and cationic SbCl2+ complexes were found. Cyclic voltammetry, anodic stripping analysis and potentiostatic measurements showed that antimony deposited favorably and the reaction run under limiting control. Analysis of chronoamperometric curves suggested instantaneous nucleation of the solid phase in the chloride bath, but progressive model was more probable in the presence of sulfate ions.

Oxide fraction of industrial zinc ash from hot dip galvanizing was characterized in terms of composition and leaching behaviour in 10% sulfuric acid solution. Waste product contained about 68% Zn, 6% Cl, 3% Al, 1% Fe, 0.7% Si, 0.5% Pb and minor percentages of other metals (Mn, Cu, Ti etc.). It consisted mainly of zinc oxide contaminated with metallic zinc, zinc hydroxide chloride and silica. Dissolution of the metals from the material was determined as a function of solid to liquid ratio (50-150 kg/m3), temperature (20°C and 35°C) and agitation rate (300 and 900 rpm). The best results (50 g/dm3 Zn(II) at 78% zinc recovery) were obtained for 100 kg/m3 and the temperature of 20°C. Increase in the agitation rate had weak effect on the zinc yield. The final solutions were contaminated mainly by Fe(II, III) ions. Leaching of the material was an exothermic process with the reaction heat of about 800 kJ/kg.