Recovery of zinc and some of its valuable salts from secondary resources and wastes

• Published in: Hydrometallurgy Vol. 37; no. 1; pp. 23 - 32
• Main Authors: Rabah, M.A., El-Sayed, A.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.1995; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Hydrometallurgy; Metals. Metallurgy; Oxidation; Production of metals; Production of non ferrous metals. Process materials; Q1; Salts; Recovery metals; Waste treatment; Concentration effect; Temperature effect; Acid leaching; Lixiviation; Pyrometallurgy; Recycling; Experimental study; Zinc; Metal scrap; Hydrometallurgy
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/0304-386X(94)00015-U

In Egypt, several kinds of recurring zinc-containing waste materials are available for metal zinc recovery. These include zinc scrap from spent dry cell batteries, zinc dross and zinc ash. These secondary resources were analyzed and their zinc contents determined. Pyrometallurgical and hydrometallurgical recovery processes for zinc and its salts were carried out. The factors affecting the performance and efficiency of the processes; such as particle size, temperature, concentration of acid leaching and time were studied. The results obtained revealed that zinc metal is successfully recovered from these secondary resources. The recovery efficiency amounts to 89% and 63% for zinc waste materials having a particle size diameter of + 1.25 mm and (− 0.4 + 0.315 mm), respectively. An optimum percentage of 10% weight of ammonium chloride fluxing agent was obtained. The optimum temperature for the recovery process was 600°C. With respect to the fine fraction of zinc dross, zinc ash and the slag left after pyrometallurgical treatment, acid leaching for extraction of the metal salts yields salts with a high efficiency (99%). The cost of recovery is acceptable on the basis of the low price of the materials input and energy consumption. Results were explained by an oxidation model and a salt refining mechanism.