Publication Date:
2018-01-20
Description:
The effect of CaO on the sulfide capacity of CaO-Al 2 O 3 -SiO 2 slags was studied from the viewpoint of the ionic structure of alumina in slag. The aluminum coordination number was analyzed using 27 Al 500-MHz solid nuclear magnetic resonance spectroscopy and the results were compared with those of the sulfide capacity analysis. The sulfide capacity of slag, in the peralkaline region 〈X cao /XA1 2 o 3 〉1.0), exhibited a linear relationship with respect to basicity (a 0 2-) as excess free Ca 2+ formed a four-coordinated aluminum unit structure ( [ IV ] Al; AlO 4 5- ) and stabilized the sulfide ions. However, sulfide capacity in the peraluminous region (X cao /X A 12os 〈1.0) exhibited a nonlinear relationship with respect to basicity (a o 2- ) owing to the structure of higher-coordinated aluminum units ( [V] Al, [ VI ] Al; Al 3+ ) and the relative lack of Ca 2+ . Therefore, the sulfide capacity of high Al 2 O 3 -bearing slags strongly depended on the basicity (a o 2- ) and stability of sulfide ions (γ s 2- ), which depended on the competitive behavior of Ca 2+ owing to the structural changes in Al 2 O 3 . The effect of the aluminum coordination number on the sulfide capacity was discussed in detail using an analysis of the slag structure and thermodynamics model. This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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