Recycling Technologies for Secondary Zn-Pb Resources, Muammer Kaya, Editör, Springer, London/Berlin , New York, ss.151-204, 2023
This chapter covers the most significant Zn secondary leaching using inorganic sulphuric acid (H2SO4) as lixiviant. The physical, chemical and thermodynamic properties of Zn compounds and H2SO4 are introduced in detail. The effects of reagent concentration, temperature, time, particle size, solid/liquid ratio, and oxidant addition on Zn dissolution are covered. The effects of sulfating roasting on Zn-ferrite are explained. Previous studies on Zn leaching were summarized along with possible reactions. EAF dust leaching, Waelz slag treatment, metal recovery from various metallurgical slags, bottom ash treatment, e-waste recycling, etc., can be used for secondary Zn metals recovery. Other than metallurgical waste, EoL automobiles, appliances, die-cast parts, trimmings, and offcuts are also available for metal recycling. Zn can be recovered from various tailings, scraps, and residues at all stages of production and use. The main secondary sources of the metals are sludges and tailings from the processing of some nonferrous metals (such as Zn, Pb, and Cu), remelted Zn/Pb ingots or pigs, dust from EAF and brass smelting, waste from hot-dip galvanizing, spent batteries and metallic scraps, etc. This chapter mainly focuses on the effect of leaching parameters using H2SO4 for Zn-oxidized ores and secondaries. Firstly, the properties of H2SO4 as a leach lixiviant are described. Then the effects of leaching temperature, reagent concentration, particle size, solid/liquid ratio, and oxidant addition on metal dissolution are summarized. A case study for leaching Turkish oxidized Pb–Zn flotation tailings leaching results is introduced. Finally, previous H2SO4 leach results for Zn ores and secondaries are extensive.