Hydrometallurgical Treatment of EAF Dust by Direct Sulphuric Acid Leaching at Atmospheric Pressure

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• 作者：V. Montenegro ; S. Agatzini-Leonardou ; P. Oustadakis…
• 关键词：EAFD ; Water washing ; Leaching ; Sulphuric acid ; EAF dust
• 刊名：Waste and Biomass Valorization
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：7
• 期：6
• 页码：1531-1548
• 全文大小：8,935 KB
• 刊物类别：Engineering
• 刊物主题：Engineering, general
  Environment
  Waste Management and Waste Technology
  Industrial Pollution Prevention
  Renewable and Green Energy
  Environmental Engineering
  
• 出版者：Springer Netherlands
• ISSN：1877-265X
• 卷排序：7

文摘

The present paper presents a part of the research efforts of the laboratory of Metallurgy, National Technical University of Athens, Greece, aiming at developing a purely hydrometallurgical method, able to treat the zincferous dust, generated during the production of steel from scraps in Electric Arc Furnace (EAF), efficiently and economically and especially so for annual capacities lower than 50,000 tonnes of dust, for which the currently applied industrial methods are not economical. The proposed method is based on direct sulphuric acid leaching of the EAF dust and it succeeds to recover the valuable metals contained in it, such as zinc, lead and cadmium, converting the initially hazardous waste into a residue suitable to be fed to cement industry. The EAF dust sample, provided by a Greek steel plant, was initially leached with water, at certain conditions, to remove as much of the contained calcium as possible without co-dissolution of other metals. The washed dust was further subjected to three–stage leaching at atmospheric pressure, using sulphuric acid concentrations of 2N and 3N and temperatures 25 °C, at the first stage, and 95 °C, at the second and third stages. Total percent extraction values achieved were 97 % for zinc and 97 % for cadmium. Almost all lead, 99.7 %, remained undissolved as lead sulphate in the leach residues. It was shown experimentally that lead can be recovered as saleable lead sulphide while zinc can be recovered from the pregnant solution by solvent extraction with D2EHPA. Finally, based on the results, a conceptual flowsheet of the proposed integrated hydrometallurgical method for the treatment of EAF dust was established and is given.