The effects of cooling rate on leaching behavior of some ferrous and non-ferrous slag systems
2012 (English)In: Model Concept and Experiments: 9th International Conference on Molten Slags, Fluxes and Salts, Bejing 27-30 May 2012, 2012Conference paper (Refereed)
It has been proven that pyrometallurgical slags can be given favorable physico-mechanical characteristics which make them suitable for use in civil engineering applications providing fulfillment of various technical and environmental criteria, of which slag leaching behavior is one of the main concerns. Numerous investigations have been carried out over the last several decades to clarify the influence of cooling rate on microstructure and properties of the slag systems; however, there is controversy in the literature as to the effect of rapid cooling, e.g. water granulation, on release of potentially toxic elements. In the current work, a ladle slag, a basic oxygen furnace (BOF) slag, two different electric arc furnace (EAF) slags, from low-alloyed and high-alloyed steel production, and three different “fayalite-type” slags, from zinc-copper smelting processes with different Fe/SiO2 ratios, are investigated. Semi-rapidly solidified (in crucible system) and water granulated samples for each composition were prepared. The solidified materials were characterized using commonly applied characterization techniques. The experimental work is compared with thermodynamic calculations using the FactSageTM thermodynamic package. Standard European leaching tests were carried out for all samples to investigate the slag leaching behaviors. Results show that rapid solidification and generated amorphous structure do not necessarily immobilize environmentally concerned elements in the glassy network. Instead, due to several factors, a higher reactivity is observed and trace elements dissolve more readily in the aqueous solution. The main reasons behind such a behavior including higher contents of metastable phases, different surface structures, oxidation and increased amount of grain boundaries are thoroughly discussed.
Place, publisher, year, edition, pages
Research subject Process Metallurgy
IdentifiersURN: urn:nbn:se:ltu:diva-34725Local ID: 901400db-b969-40f0-987a-f52e2f9e225fOAI: oai:DiVA.org:ltu-34725DiVA: diva2:1007976
International Conference on Molten Slags, Fluxes and Salts : 27/05/2012 - 30/05/2012
Godkänd; 2012; 20120224 (sinmos)2016-09-302016-09-30Bibliographically approved