Bubble formation and dynamic slag foaming phenomena
2006 (English)In: 2006 TMS Fall Extraction and Processing Division: Sohn International Symposium, 2006, p. 233-245Conference paper, Published paper (Refereed)
Abstract [en]
Slag foaming proves to be both blessing and curse for the process productivity, depending on where in the process it occurs. In pyrometallurgical processes, slag foaming is often a result of chemical reactions taking place in the slag. As the slag composition and reaction rates are changing, foaming occurs under dynamic conditions. In the present work, slag foaming was studied with XRF. The foam displayed a fluctuating behaviour, unaccountable by existing models. The concept of foaming index was found not to be satisfactory in describing the foam, resulting in the need for alternative theories. The rate of fluctuations was seen to be related to the difference between rate of gas generation and rate of gas escape from the system (Ug-Ue) as well as the bubble sizes. Thus, model development of dynamic foaming phenomenon has to take the effective chemical reaction rate as well as the bubble sizes into consideration. The first step in obtaining foam is to form bubbles. In the present work, gas bubbles were generated through chemical reaction at interface between two immiscible liquids and the bubble formation was studied optically. The gas bubble size was seen to be uninfluenced by the reaction rate. However, bubble formation was seen to take place in one of the phases and since the bubbles consequently traversed the interface under the influence of buoyancy, the viscosity of the first phase was found to influence the final bubble size where increased viscosity would yield a larger bubble size.
Place, publisher, year, edition, pages
2006. p. 233-245
Series
2006 TMS Fall Extraction and Processing Division: Sohn International Symposium ; 2
Keywords [en]
Bubble, Foaming, Slags, Steelmaking, Bubbles (in fluids), Buoyancy, Foams, Pyrometallurgy, Reaction kinetics, Foaming index, Immiscible liquids, Slag foaming
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-155870Scopus ID: 2-s2.0-33846040374ISBN: 0873396332 (print)ISBN: 9780873396332 (print)OAI: oai:DiVA.org:kth-155870DiVA, id: diva2:764033
Conference
2006 TMS Fall Extraction and Processing Division: Sohn International Symposium, 27 August 2006 through 31 August 2006, San Diego, CA
Note
QC 20141118
2014-11-182014-11-132022-09-08Bibliographically approved