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Mass Spectrometric Measurements of the Gas Phase Composition over Mould Powder Samples in Vacuum Conditions at 50‐1550°C
Author(s) -
Shilov Andrei,
Holappa Lauri
Publication year - 2006
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.200606465
Subject(s) - analytical chemistry (journal) , knudsen number , materials science , volatility (finance) , volatilisation , atmospheric temperature range , metallurgy , chemistry , environmental chemistry , thermodynamics , financial economics , economics , physics , organic chemistry
Heating and melting of mould powders in a steel caster may lead to harmful gaseous emissions into the atmosphere. In the present work the volatility of commercial mould powders used in continuous casting processes was studied by the mass spectrometric Knudsen effusion method. Partial pressures of the vapour phase components were measured under vacuum conditions in the temperature range 50‐1550°C at a heating rate of 100°C/hour. In the temperature interval 50‐600°C gas phase is formed by H 2 O and CO 2 . At higher temperatures the principle vapour species are Na, NaF, Na 2 F 2 , KF, SiF 4 , SiF 2 , SiO, CaF 2 , and CO. Gaseous AIF 3 , MgF 2 and AIOF were identified less reliably. A preliminary decarburised sample exhibited a noticeably different vaporisation pattern. HF was not detected. Under plant conditions SiF 4 was pointed out as the most probable air polluting vapour component.